WO1993014228A1

WO1993014228A1 - Improved plant and process for fluidized bed reduction of ore

Info

Publication number: WO1993014228A1
Application number: PCT/US1992/000457
Authority: WO
Inventors: Roy H. Whipp
Original assignee: Whipp Roy H
Priority date: 1992-01-17
Filing date: 1992-01-17
Publication date: 1993-07-22
Also published as: AU1267192A

Abstract

An improved FIOR processing plant (11) and method for reducing raw iron ore fines into a 90+ % metallized briquette product utilizing a multi-stage fluidized bed reactor (403, 405, 407) in which reducing and fluidizing gases being introduced into an intermediate zone (403) of the reducing tower (401) above the stage or stages where final metallization occurs. Said processing plant (11) including an ore preparation (101) and feed assembly (201), a multi-stage reactor assembly (401), a briquetting assembly (801), a recycle gas assembly (601), a reducing gas assembly (501), and a heat recuperation assembly (603).

Description

IMPROVED PLANT & PROCESS FOR FLUIDIZED BED REDUCTION

OF ORE BACKGROUND OF THE INVENTION Field of the Invention

This invention relates to a method for reducing ore; and more particularly to an improved FIOR method for producing a stable, reduced iron ore from ore fines. Description of the Prior Art

Previously, there have been a number of methods and processes for reducing ore by means of fluidized-bed reactors, which use gas or gas mixtures to reduce the ore and to fluidize the bed. The reducing and fluidizing gas for these processes is produced in special plants, for instance by the steam-reforming process, starting from hydrocarbons and steam. However, that process requires separate plants for gas production and these are very costly, thus markedly increasing the cost of the final product.

Another way of preparing the reducing gases is also known, involving the partial combustion of fuel oil and other higher hydrocarbons.

The injection of a sub-stoichiometric mixture of hydrocarbons and air directly into the reducing bed has also been proposed. Although this does away with the costly plants previously needed to make reducing gases, it has its drawbacks: for instance, the sulphur content of the fuel oil, which contaminates the metal produced, the fact that part of the hydrocarbon cracks producing carbon black directly in the reducing bed, and the fact that the nitrogen contained in the air used builds up in the plant.

Accordingly, there is a need for a process eliminating these drawbacks, permitting direct reduction of ores in fluid beds cheaply and with no possibility of the metal produced being contaminated with sulphur.

The FIOR process was developed by ESSO Research and Engineering Company in the late 1950's and early 1960's. The process was intended to produce Direct Reduced Iron (DRI) briquettes by a Fluidized Iron Ore Reduction (FIOR) processing scheme which used iron ore fines as a feedstock. The fluidizing gas was provided by the reforming of light hydrocarbon gases.

The first process development work was done at a 5 ton/day pilot plant at the ESSO Research Labs in Baton Rouge, La. Test work began in 1962 and terminated in1966. Based upon the preliminary results of this test work, a semi-commercial plant was built in Darmouth, Nova Scotia. The plant had a design capacity of 300 tons/day, and operated from 1965 to 1969. A total of 56,000 tons of DRI briquettes were produced, equivalent to only 15% of the expected production at the design rate.

During the ensuing years, the plant operations personnel continued to improve the process by way of mechanical and operational refinements. These refinements were often implemented in the field without benefit of engineering studies, due to the limited resources of the company. These improvements resulted in a steady increase in production, and the plant reached 96% of design production in 1986.

Competing pellet based DRI processes cannot utilize iron ore fines for feed as the FIOR process does. These processes had previously required much less energy per ton of product, but their energy consumptions have increased recently as they have incorporated hot briquetting, a process that FIOR research pioneered. Therefore, an improved FIOR design could be more viable than competing DRI processes for many areas which possess large quantities of ore fines, have low energy costs, and need to export DRI. The net result of this developmental process is that the present plant design and operation has improved over the original contemplated designs. A new plant utilizing the FIOR process would have to incorporate the changes in order to be thermally efficient and economical. in addition to these already implemented changes, a new plant design would have to include equipment and process improvements that are made possible by current technology and by better knowledge of the process shortcomings.

The previous design was not intended to be thermally efficient due to the very low natural gas prices that were prevalent 15 years ago. Today, a DRI plant has to be as thermally efficient as possible due to the high incidence of fuel cost upon the overral production cost, even in countries with relatively inexpensive energy. The improved design contemplates a 25% decrease in energy requirements as compared to the previous design.

The plot configuration utilized in the previous design was not optimized with respect to economy of layout. The previous design is a hybrid of old refinery and steelmaking technology, and is characterized by large plot areas. Competing DRI processes are much more compact. A more compact FIOR plant layout would result in economies of construction (less piping and structure) and operation (fewer operators). The improved design will result in a reduction in plant operating equipment plot areas of up to 40%, and a decrease in operating manpower of up to 25%.

Another area covered by the improved design is mechanical reliability. Some pieces of mechanical equipment that have historically been troublesome in the previous design are either replaced by more reliable equipment or removed in the improved design. In addition, design improvements have been included to eliminate problems of dust ingestion into equipment, which has caused equipment operating problems in the previous design.

Summary of the Invention The present invention is directed to an improved process for reducing ore utilizing a multi-stage fluidized bed reactor in which the reducing and fluidizing gases are the products of partial combustion of methane with oxygen, the gases being introduced into an intermediate zone of the reducing tower above the stage or stages where final metallization occurs. The process takes place at pressures of between 1 and 15 atmospheres and methane and oxygen in sub-stoichiometric proportions, are introduced into a combustion chamber, the outlet of which is connected to the reactor in an intermediate zone, for instance: between the last and the next-to-the-last reduction beds. In the reduction chamber the methane reacts with the oxygen to produce carbon monoxide, hydrogen and water and a small percentage of carbon dioxide. Part of the methane, generally less than 10%, remains unburnt and circulates in the reactors without causing trouble. The gas thus produced, together with the gas coming from the lower stages of metallization, passes through the upper beds where the ore is in a low-reduced state. In this way the amounts of CO2 and H2O present do not hinder the progress of this phase of the reduction process. Once the reducing gas has passed through the reactor and emerged from its top, the dust and the water it has picked up are separated out and the CO2 removed, after which the gas is reheated and sent to the last reducing bed.

In this way, the reducing gas, composed essentially of CO and H2, is fed precisely in the zone where the presence of a pure reducing gas is most necessary, thus completing the ore reduction process. The carbon black produced in the partial combustion chamber can be removed before it enters through the grating of the overlying fluidized bed.

Accordingly, it is the principal object of this invention to provide a more efficient FIOR process.

A further object of this invention is to provide a more economical FIOR process.

A further object of this invention is to provide a more compact FIOR process.

A further object of this invention is to provide a process where fouling of reactor internals is minimized or reduced.

A further object of this invention is to provide a stable reduced product which is easily transported over long distances. Brief Description of the Drawings

For a fuller understanding of the nature of the present invention, reference should be had to the following detailed description taken in connnection with the accompanying drawings in which:

Figure 1 is a perspective view of the overall plant including ore preheat reactor assembly, reducing reactor assembly, and recycle gas assembly.

Figure 2 is a perspective view of the ore preparation and feed system.

Figure 3 is a perspective view of the reducing gas, reformed heat recuperation, reformed gas cooling and shift, and reformed gas

CO2 removal systems .

Figure 4 is a perspective view of the briquetting system.

Like reference numerals refer to like parts thoughout the several views of the drawings and numbers in ( ) correspond to stream properties . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The Plant Assembly: As shown in Figure 1, the present invention is directed towards a processing plant assembly, generally referred to as 11, and process for reducing finely divided iron oxide material in a circulating fluidized bed. Hereinafter, individual components and assemblies shall be referred to numerically and may be referenced in the drawings. In addition, flow streams and product referred to in the process description shall be referred to by numerals in parentheses ( ) and may be referenced in the table included at the end of the detailed description describing the composition of said flow streams and product.

Referring to Figure 1, the processing plant assembly 11 is comprised of an ore preparation assembly 101, an ore feed assembly 201, a preheat reactor assembly 301, a reducing reactor assembly 401, a reducing gas preparation assembly 501, a recycle gas assembly 601, a reducing gas delivery assembly 701, a briquetting assembly 801, and, a utilities assembly. The Ore Preparation Assembly

Referring to Figures 1 and 2, the ore preparation assembly 101 is comprised of an ore feed loading hopper 103 for loading ore from trucks, etcetera; a conveyor belt 105 for conveying ore from the hopper 103 to a drier feed bin 107; a drier weigh feeder 109 for conveying a measured amount of ore to an ore drier 111; an air blower 113 for blowing combustion air through a furnace section of the drier 111; dry cyclones 115 for separating entrained ore fines from combustion gases leaving the drier 111; a conveyor 117 for conveying ore from the drier 111 to a splitter hopper 119; a diverter gate 121 for diverting ore from said splitter hopper 119 to two main ore feed bins 123, 125.

Wet iron ore fines under 1/2" in diameter and with a suitable particle size distribution for use in fluid beds are loaded into the ore feed loading hopper 103, which is located at grade. The fines are transferred from the hopper 103 by a conveyor belt 105 to the drier feed bin 107. The drier feed bin 107 includes a drier weigh feeder 109 located at the discharge outlet. The feeder 109 provides an adjustable, continuous ore fine feed rate in order that ore may be metered out at a pre-determined rate to the ore drier 111.

The ore drier 111 is a rotary kiln drier burning natural gas fuel provided at natural gas inlet 112 in a stream of air provided by a blower 113. The ore drier 111 dries the wet iron ore fines under 1/2" to a free water content of under 0.2% and a temperature of 100-110°C. The dried ore fines exitting the drier 111 are deposited onto a conveyor 117 for further transport.

Combustion gases exiting from the drier 111 are directed by an exhaust pipe network 127 through dry cyclones 115 in order to remove entrained ore fines, through a venturi type scrubber 129 to clean the exhaust gases, through an induced draft fan 131 utilized to accelerate the flow of exhaust gases, and out of a vent stack 133 into the atmosphere. The de-entrained ore fines settle to the bottom of the dry cyclones 115 where they are either re-directed onto the conveyor 117 with the ore fines mainstream or are deposited into a storage pile 116.

The conveyor 117 provides a transport means for conveying fines from the the drier feed bin 107 to the two main ore feed bins 123, 125. A splitter hopper 119 and diverter gate 121 are located above the two ore feed bins 123, 125 and beneath the end of the conveyor 117 for diverting fines into either or each of the respective main feed bins 123, 125 from the conveyor 117. The two main feed bins 123, 125 have level probes to avoid overfilling and closable outlets at the bottom to allow for flow of ore fines into the ore feed assembly 201, and include a storage capacity of a 10-12 hour inventory of fines. The 10-12 hour storage capacity allows the ore preparation assembly to be shut down for maintenance without affecting plant operation. The Ore Feed Assembly

Referring to Figures 1 and 2, the ore feed assembly 201 is comprised of two variable speed feed conveyors 203 and 205; two high angle flexible wall type conveyors 207 and 209; two discharge chutes 211 and 213; a lockhopper surge bin 215; a lockhopper charge conveyor 217; a weigh, bin 219 including multiple load cells 221; a diverter valve 223; two reactor ore feed systems 225, 227; two rotating drum feeders 261, 263; and, preheater reactor connecting pipes 269, 271 equipped with isolation valves 273, 275.

Two variable speed feed conveyors 203, 205 located beneath the main feed bins 123, 125 are each designed to handle a feed capacity of up to 120% of the plant design feed rate to the preheat reactor assembly 301 and transport the ore from the two main ore feed bins 123, 125 onto two high angle flexible wall type conveyors 207, 209. The excess capacity of the conveyors 203, 205 allows for usage of only one conveyor 203 or 205, one main feed bin 123 or 125, and one conveyor 207 or 209 during a given period of time. The design is such that the feed bin 123 feeds into the conveyors 203 and 207; while the feed bin 125 feeds into the conveyors 205 and 209. The high angle conveyors 207, 209 carry the ore fines to the top of a reactor structure, which contains the preheat and reactor assemblies 301, 401 and is about 80 meters above grade. From the high angle conveyors 207, 209, the ore is fed through two special discharge chutes 211, 213, corresponding to respective of the conveyors 207, 209, and into a lockhopper surge bin 215 located at the top entrance of the reactor structure. The lockhopper surge bin 215 is implemented in order to assure constant ore feed to the preheat assembly 301. A lockhopper charge conveyor 217 is located beneath the discharge port of the surge bin 215 and transports ore from the lockhopper surge bin 215 to the weigh bin 219. The weigh bin 219 includes multiple load cells 221 for weighing a pre-determined charge of ore. Once this pre-determined amount has been deposited into the weigh bin 219, the charge conveyor 217 automatically shuts down.

The surge bin 215 includes level probes for maintaining surge bin levels within a pre-determined range. The level probes connect to controls monitoring the speed of said variable speed conveyors 203, 205 for automatic adjustment of feed rate depending on the surge bin levels.

Once the weigh bin 219 is filled, a valve is opened at the bottom of said weigh bin 219 and a diverter valve 223 located beneath the weigh bin 219 directs the depositing of fines into one of two ore feed systems 225, 227.

The two reactor ore feed systems 225, 227 are situated in parallel, where each of said reactor ore feed systems 225, 227 is designed to individually meet a pre-specified preheat reactor ore feed rate in order that one of the two feed systems 225, 227 may deliver said pre-specified preheat reactor ore feed rate in the event of mechanical failure of the other feed system 225, 227. Each of said reactor ore feed systems 225,- 227 comprises an upper lockhopper 229, 231 respectively, a lower lockhopper 233, 235 respectively, connected in series, and a pressurizing system (not shown) for pressurizing the respective lockhoppers 229, 231, 233, 235. Each of said lockhoppers 229, 231, 233, 235 comprise a conical pressure vessel 237, 239, 241, 243; and, a material inlet valve 245, 247, 249, 251.

The weigh bin 219 being located above the upper lockhoppers 229, 231 allows for gravity feed to the respective reactor ore feed sy ms 225, 227. When the weigh bin 219 is emptying its co ents, the material inlet valves 245, 247 of the upper lockhoppers 229, 231 are open to receive the dry ore fines at atmospheric pressure. During this filling process, the material inlet valves 249, 251 of the lower lockhoppers 233, 235 remain closed in order to maintain the lower lockhopper pressure at pre-determined preheat reactor pressure levels. Once the contents of the weigh bin 219 have been emptied into the upper lockhoppers 229, 231, the material inlet valves 245, 247 are closed and the upper lockhoppers 229, 231 are pressurizable.

The upper and lower lockhopper pressure vessels 237,239, 241, 243 are respectively pressurizable by said pressurizing system to a pre-determined preheat reactor pressure, such that the pressure of said upper and lower vessels may be equalized, once the pressure between the two lockhoppers is equal, and the lower lockhoppers 233, 235 have a low ore inventory, the material inlet valves 249, 251 opens and the entire ore charge is transferred to the lower lockhoppers 233, 235 by gravity. The material inlet valves 249, 251 between the two lockhoppers then closes and the upper lockhoppers 229, 231 are de-pressurized to await another charge. The ore contained in the lower lockhopper 233, 235 is metered into the preheat reactor assembly 301 by rotating drum feeder 261, 263. The conducts 269, 271 connect the lockhoppers 233, 235 to the preheat reactor assembly 301. The Ore Preparation and Feed Process

Referring to Figure 2, wet iron ore fines under 1/2" in diameter and with a suitable particle size distribution for use in fluid beds are loaded into an ore feed loading hopper 103 located at grade. The fines are transferred from the hopper by a conveyor belt 105 to a drier feed bin 107 which is equipped with a drier weigh feeder 109 at the discharge of the bin. The feeder provides a constant but adjustable ore fines feed rate to the ore drier 111.

The ore drier 111 is a rotary kiln drier which dries the wet iron ore (39) to a free water content of under 0.2%. The drier 111 burns natural gas (41) in a stream of air (42) provided by a blower 113. The combustion gases (43) exiting from the drier pass through dry cyclones 115 where part of the entrained fine ore particles are removed. The fines can either be returned to the dried ore being transported to the main ore feed bins 123, 125, or they can be diverted to the ore storage area 116 in the event that there are excess fines in the reducing reactor circuit. The combustion gases are directed along a line 127 to be cleaned in a venturi type scrubber 129, exhausted via an induced draft fan 131, and vented through a vent stack 133.

The dried ore (40) exits the drier at a temperature of 100-110 °C, and is transported by a conveyor 117 to a splitter hopper located above the two main ore feed bins 123, 125. The ore fines are directed to one of the two bins by means of a diverter gate 121. The bins are equipped with level probes to avoid overfilling.

The two main feed bins contain a 10-12 hour inventory of iron ore. This allows the ore preparation area to be shut down for maintenance without affecting plant operation. The bins are equipped with variable speed feed conveyors 203, 205 on the bottom. The variable speed feed conveyors are designed for up to 120% of the design dry ore feed rate to the reactor circuit, which permits using only one main feed bin and one conveyor at a time. The feed conveyor in service discharges onto a high angle flexible wall type conveyor 207 or 209 which carries the ore fines to the top of the reactor structure, about 80 meters above grade. Each main feed bin is equipped with a flexible wall conveyor in order to guarantee constant ore feed to the process. The discharge chutes of the two flexible wall conveyors terminate in a lockhopper surge bin 215 at the top of the reactor structure.

The lockhopper surge bin is equipped with a lockhopper charge conveyor 217 which feeds ore into a weigh bin sitting on load cells. The charge conveyor shuts down when the total weight in the bin reaches a preset amount. A diverter valve 223 located below the weigh bin directs the ore charge to one of the two ore feed systems. The lockhopper surge bin is equipped with level probes which speed up or slow down the variable speed feed conveyor on the main ore feed bin that is in service in order to maintain the lockhopper surge bin level within an acceptable range.

There are two parallel reactor ore feed systems which consist of two lockhoppers in series. A lockhopper is a conical pressure vessel which has material inlet and outlet valves as well as a pressurizing system using compressed air. Once the ore charge has been weighed into the upper lockhopper 229 or 231 from the surge bin, the upper mineral inlet valve is closed and the lockhopper is pressurized to preheat reactor pressure. Once the pressure between the two lockhoppers is equal, and the lower lockhopper has a low ore inventory, the valve between the two lockhoppers opens and the entire ore charge is transferred to the lower lockhopper 233 or 235 by gravity. The valve between the two lockhoppers then closes and the upper lockhopper is depressurized to await another charge. The ore contained in the lower lockhopper is metered into the preheat reactor by a rotating drum feeder 261 or 263.

Both of the two parallel ore feed lockhopper systems are designed for up to 120% of the design ore feed rate to the preheat reactor. Normally both systems are in service at a 50% capacity. In case of a mechanical failure in one of the two systems, it is removed from service and the capacity of the other system is increased to 100% in order to maintain ore feed rate. The Preheat Reactor Assembly

Referring to Figure 1, the preheat reactor assembly 301 is comprised of an ore preheat reactor 303 including dry ore feed inlet ports 305, 307, preheated dry ore (33) feed outlet ports 308, 314, an air intake port 310, and a gas exhaust port 312; a combustion air supply assembly 309; a natural gas supply assembly 311; an exhaust gas assembly 313; and, a preheat reactor feeder assembly 315.

The preheat reactor 303 comprises a carbon steel shell; a dual insulation and refractory layer internally lining said shell; a gas distribution grid in the lower part of the reactor 303; and, a cyclone system in the upper part of the reactor. The grid and cyclone system are made of heat resistant alloy. The grid comprises a flat perforated circular plate that is slightly smaller in diameter than the inside of the reactor. The circular plate is sealed to said steel shell by means of a vertical cylinder comprised of thin plate steel supported centrally by vertical, small diameter tubes jutting through holes perforated in said circular plate and welded in place.

The cyclone system is comprised of pairs of primary and secondary cyclones. The cyclones are located in front of the gas exhaust port 312 and are designed to remove entrained iron ore fines from exiting combustion gases. A recycle conduit connects the material outlet of the cyclone to the bottom of the reactor 303 providing a path for de-entrained ore fines to be returned to the main ore fines flowstream prior to exiting through the ore outlet port 308.

The air intake port 310 is located at the bottom of the reactor 303, so that any entering air flow is forced through said tubes providing an evenly distributed gaseous flow across the cross sectional area of said preheat reactor. A combustion air supply assembly 309 is designed to provide desired quantities of forced air flow through the intake port 310, developing a counter-current flow to the ore fines gravity flow, and creating a fluidized bed of iron ore fines.

A series of natural gas burners are located inside said preheat reactor 303 about 1 meter above the grid and are supplied by a natural gas assembly 311. Preferably, an air to natural gas ratio is maintained so that there is about 2% 02 content in the flue gas for good combustion.

The combustion air supply assembly 309 includes a centrifugal air compressor 317 and a reformer heat recuperation system 319. The centrifugal air compressor 317 is equipped with suction filters to eliminate dust and water-cooled intercoolers to remove the heat of compression. The combustion air is compressed to about 13-14 kg/cm2, and is preheated to 700-750 degrees C in the reformer heat recuperator system 319.

The exhaust gas assembly 313 includes a refractory lined reactor outlet pipe 321; a gas quench assembly 323, aventuri type scrubber 326; an exhaust line 325 including two pressure letdown valves 327, 328; and, a stack 329. The refractory lined reactor outlet pipe 321 connects the gas exhaust port 312 to the gas quench assembly 323. From the gas quench assembly 323, the exhaust line 325 carries the cooled exhaust gas through the venturi scrubber 326, through the pressure letdown valves 327, 328 for depressurizing the exiting gases before release, and through the stack 329 for release into the atmosphere.

The preheat reactor feeder assembly 315 includes a fabric of linking refractory lined pipes extending from the ore feeder assembly 301 through the preheat reactor and to the reactor assembly 401. A pair of refractory lined, preheat reactor ore inlet pipes 331, 333 connect the dry ore feeder outlet pipes 269, 271 to the ore inlet ports 305, 307 located near the top of said preheat reactor 303. The ore inlet pipes include isolation valves for maintaining constant solid flow from said feeder assembly 201 and into the reactor assembly 301. Additionally, an inert gas source supplies a flow of inert gas into said refractory lined pipe preventing air from being carried within said inlet pipe and into the reactor assembly 301. A pair of refractory lined preheater outlet pipes 335, 337 connect the outlet ports 308, 314 of preheat reactor 303 to the inlet ports of reactor 403. The preheater outlet pipes 335, 337 include cycling slide valves for maintaining continuity of ore fines flow. The resulting cascading structure provides a flow path for ore fines to travel downward in a gravity flow through the preheat reactor 303 and to the reactor assembly 401 in series fashion, where the feeder assembly 201, preheat reactor assembly 301, and the reactor assembly 401 have been fixed in graduated, decreasing height to facilitate gravity flow of the iron ore fines. The preheater outlet pipes 335, 337 include cycling slide valves for maintenance of a constant solid flow from the preheat reactor 303. Additionally, an inert gas source supplies a flow of inert gas into said refractory lined pipes preventing air from being carried within. The Ore Preheat Reactor Process

Referring to Figure 1, the dry iron ore (32) from the two ore feed systems passes through pipes equipped with isolation valves into the ore preheat reactor 303. The function of the preheat reactor is to heat the ore to reaction temperature and to remove hydrated water and some sulfur and phosphorous from the ore. This is accomplished by fluidizing the iron ore fines in an upflowing air stream (13) and burning natural gas (24) that is injected into the fluid bed. Since the temperature of the bed is about 750°C, the natural gas burns upon contact with air. A slight excess of air is provided. The combustion air is provided by a centrifugal air compressor 317 equipped with suction filters to eliminate dust and with water cooled intercoolers to remove the heat of compression. The air is compressed to about 13-14 kg/cm2 with the centrifugal air compressor 317, and is preheated to 700-750 °C in the reformer heat recuperator system 319. The natural gas is injected by a series of burners located around the reactor about 1 meter above the grid. The air to gas ratio is maintained so that there is about 2% 02 in the flue gas (dry). A purge gas consisting of steam is injected to the burners to prevent plugging when natural gas flow is low.

The preheat reactor is constructed of a carbon steel shell and has a dual layer internal lining of insulation and refractory. The reactor contains a gas distribution grid in the lower part and a cyclone system in the upper part. These components are constructed of a heat resistant alloy. The grid consists of a flat perforated circular plate that is slightly smaller in diameter than the inside of the reactor. The plate is sealed to the vessel shell by way of a vertical cylinder made of thin plate, and is supported in the center by vertical pipes. Small diameter tubes are placed through the holes perforated in the flat plate and are welded in place. The fluidizing air which enters through the bottom of the reactor is forced through the tubes, which provides an even air flow distribution across the cross-sectional area of the reactor.

The cyclones consist of pairs of primary and secondary cyclones which remove entrained iron ore fines from the combustion gases exiting the fluid bed. The fines removed by the cyclones are returned to the fluid bed. The gases (31) exit the cyclones through outlet pipes and pass through a refractory lined reactor outlet pipe 321 to the quench and gas cleanup assemblies 323, 326. The combustion gases have to be cooled and scrubbed of fines prior to being vented. The cooling is done by a water quench assembly 323, although it is possible to cool the gas by producing steam in an exchanger. After cooling, the gases are scrubbed in a venturi type scrubber 326, and are vented via pressure letdown valves 327, 328 to a stack.

The preheat reactor 303 is connected to the first reducing reactor 403 by two refractory lined pipes 335, 337 equipped with cycling slide valves which maintain a constant solids flow to the reactor assembly 401. A flow of inert gas is injected into the lines 335, 337 to prevent air from being carried into the reactor assembly 401. The Reducing Reactor Assembly

Referring to Figure 1, The reducing reactor assembly 401 is comprised of a series of three ore reducing reactors 403, 405, 407; a reactor ore feeder assembly 409; and, a reducing gas feeder assembly 411.

The three ore reducing reactors 403, 405, 407 are oriented in a graduated grade, series arrangement, where reactor 403 is fixed at a highest grade level and is referred to as the uppermost reactor 403 and reactor 407 is fixed at a lowest grade level and is referred to as the lowermost reactor 407. Each of said three reducing reactors 403, 405, 407 include two ore inlet ports 419, 421; two ore outlet ports 423, 425; a reducing gas intake port 427; a reducing gas exhaust port 429; a vertical, upper reaction chamber 431, downwardly connected to a lower, narrower, vertical reaction chamber 433. The reducing gas intake port 427 is located at the bottom of the lower reaction chamber 433 for receiving fluidizing gas, and, the reducing gas exhaust port 429 is located at the top of the upper reaction chamber 431 for passing the fluidizing gas out of the respective reactor. The respective ore outlet ports 423, 425 are located near the bottom of the lower reaction chamber 433 for passing the reduced ore out of the respective reactor, and, the respective ore inlet ports 419, 421 are located at the top of the upper reaction chamber 431 for receiving ore fines; a cyclone separator (not shown) is located within the upper reaction chamber 431 and in front of the gas exhaust port 429, in order to separate entrained ore fines from the circulating fluidization gas before passing out of the respective reactor; a recycling conduit (not shown) connects the material exhaust portion of the cyclone separator to the bottom of the lower reaction chamber 433 establishing a channel through which the de-entrained fines may flow to rejoin the mainstream ore flow prior to passing through the ore outlet ports 423, 425.

The cyclone separator comprises a pair of primary cyclones and externally actuated valves, where the externally actuated valves seal off the cyclones in the event said cyclones become plugged with iron ore fines. By utilizing only primary versus a primary-secondary pair of cyclones as in the preheater reactor the vessel height can be reduced by 5 feet.

Each of said reactors comprises a carbon steel shell, and a dual insulation and refractory layer internally lining said shell. Each of the reactors further include a gas distribution grid located across the cross-section of the lower part of the lower vessel 433, where the grid provides a distribution path through which an upflowing stream of reducing gas is forced to pass resulting in an evenly distributed, counter-current flow to that of the iron ore fines developing a fluidized bed of said fines.

The gas distribution grid is formed of heat resistant alloy and comprises a flat perforated circular plate that is slightly smaller in diameter than the inside of the reactor. The circular plate is sealed to said carbon steel shell by a vertical cylinder made of thin plate steel and supported centrally by vertical, small diameter tubes which jut through holes perforated in the circular plate and are welded in place. It is these tubes through which the reducing gas stream is forced to provide an evenly distributed reducing gas flow across the cross sectional area of said reactor. In the case of reactor 403 and 405, the tubes are replaced with cones to prevent rapid plugging of the grid by reduced ore fines carried by the gas.

The reactors incorporate the same design features as the preheat reactor, except that they are larger in diameter and have only primary cyclones instead of primary-secondary sets. The cyclones are equipped with externally actuated valves which allow the cyclones to be sealed off if they plug up with iron ore fines.

The reactor ore feeder assembly 409 includes a fabric of linking refractory lined pipes extending from the preheat reactor assembly 301 through the reactors of the reactor assembly 401 and to the briquette feeder assembly 801. A pair of refractory lined, preheater ore outlet pipes 335, 337 connect the preheater ore feed outlet ports 308, 314 located near the bottom of said preheat reactor 303 to the ore inlet ports 419, 421 of the uppermost reactor 403. The ore inlet pipes 335, 337 include cycling slide valves for maintaining constant solid flow from said preheat reactor 303 and into the reactor assembly 401. Additionally, an inert gas source supplies a flow of inert gas into said refractory lined pipe preventing air from being carried within said inlet pipe and into the reactor assembly 401. A pair of refractory lined outlet pipes 435, 437 connect the outlet ports of reactor 403 to the inlet ports of reactor 405; a pair of refractory lined outlet pipes 439, 441 connect the outlet ports of reactor 405 to the inlet ports of reactor 407; and, a pair of refractory lined outlet pipes 443, 445 connect the outlet ports of reactor 407 to the inlet ports of the briquetting assembly 801. The resulting structure of cascading reactors and piping provides a flow path for ore fines to travel downward in a gravity flow through each of the reactors and to the briquetting assembly 801 in series fashion, where each of said ore reactors has been fixed in graduated, decreasing height from said uppermost reactor 403 to said lowermost reactor 407. Said refractory lined pipes 443, 445 extending from the lowermost reactor 407 include cycling slide valves for maintenance of a constant solid flow from said lowermost reactor 407. Additionally, an inert gas source supplies a flow of inert gas into said refractory lined pipes preventing air from being carried within.

The reducing gas feeder assembly 411 includes: 1) a pipe 447 connecting the intake port of the lowermost reactor 407 to a reducing gas assembly 701 supplying recycled and fresh pressurized reducing (hydrogen) gas; 2) a pipe 449 connecting the exhaust port of the lowermost reactor 407 to the intake port of the reactor 405; 3) a pipe 451 connecting the exhaust port of the reactor 405 to the intake port of the uppermost reactor 403; 4) a pipe 453 connecting the exhaust port of the uppermost reactor 403 to a recycle gas assembly 601; and, a pipe 448 connecting an inlet port of reactor 407 to a supply for providing fine oxide powder for preventing deflύidization, small quantities of natural gas to maintain carbon control, and small quantities of sulfur, if required to protect reducing gas heater tubes from metal dusting attack. Said reducing gas assembly 701 supplying a reduction agent. The Reducing Reactor Process

Referring to Figure 1, the function of the reducing reactors is to remove oxygen from the iron ore fines (33) in fluidized beds using a reducing gas (27) as the fluidizing medium. There are three fluid beds (33,34,35) in series. The ore fines flow downwards by gravity and the gas flows upward between the reactors in a counter-current manner. This counter-current contacting results in a higher utilization of the reducing gas as compared to a single or dual fluid bed system.

The iron ore fines increase in metallization or purity as they pass downward from reactor to reactor. The transfer between the reactors is made by two external refractory lined pipes which connect the reactors. The transfer lines have slide valves to initiate solids flow on start-up, but the valves are left open during normal operation. The entrance to the transfer lines is located about 2 meters above the gas distribution grid inside the reactor so that a dense phase fluidized bed exists above the grid. The ore fines fall into the transfer line by overflow and pass to the next lower reactor by gravity. A pressure seal is maintained in the transfer line by a column of fluidized solids at the solids exit from transfer line.

The reducing gas used to remove oxygen from the ore is of a pre-specified composition and is pre-heated to about 850-875 °C prior to entering the lowest reducing reactor. This is necessary since the reaction occurs much more rapidly at high temperature, and heat is required to sustain the endothermic reduction reaction. Higher temperature also makes the ore easier to briquette.

The pre-heated reducing gas passes through the grid of the bottom reactor 407 and reacts with the ore solids as it passes upwards through the fluid bed. The gas is cleaned of entrained solids in the cyclones, exits the reactor via a refractory lined pipe, and is passed on to the next reactor 405. The gas distribution grids of the middle and upper reducing reactors are provided with inverted cones instead of tubes. This prevents rapid plugging of the grid by reduced ore fines carried by the gas. The spent reducing gas (30) exiting the third reactor is sent on to the recycle gas assembly 601.

In order to prevent the defluidization of the iron ore particles in the fluid bed, an additive, which consists of a fine oxide powder, is added to the bottom reactor. The additive is metered into the reactor at a rate sufficient to provide about 0.3% of the additive on the product. A small amount of natural gas is also injected into the bottom reactor to maintain carbon control within range. Sulfur can also be added to the lowermost reducing reactor 407 to form a small amount of H2S if required to protect the reducing gas heater tubes from metal dusting attack.

Gas purges are provided for instrumentation pressure taps and to maintain blasting connections clean. All purges in the reactor circuit use dried process purge gas which comes from the spent reducing gas recycle assembly 601. The carrier gas for the additive is also process purge gas. By not using inert gas as purge, higher recycle rates are permitted and less recycle gas is purged, which improves system efficiency. The reduced iron product (36) is transferred from the bottom reducing reactor 407 to the briquetter feed drum 805 through a pneumatic transfer line. The solids withdrawal rate from the reactcr is controlled by a cycling slide valve at the reactor outlet, which results in a semi-pneumatic type of transport.

A quench drum 807 that is connected to the bottom reactor is provided for use when the briquetters are out of service, and the reducing reactors are in operation. A cycling slide valve in the line allows ore to be dumped at a regulable rate. It is necessary to maintain a flow of ore through the reactors at all times, and the quench drum allows this to be carried out even when the material can not be briquetted. The Reducing Gas Preparation Assembly

Referring to Figure 3, a fresh reducing gas (hydrogen) preparation assembly 501 produces hydrogen from natural gas; although other methods of producing the reducing gas are compatible with the process. The reducing gas preparation assembly 501 is comprised of a reformer 503 fueled by natural gas supplied by a utility, a condensate knockout drum for natural gas, a heat exchanger 515 for heating natural gas, an hydrogenation vessel 517, two desulfurization drums 519, 521, a steam drum 523, a forced draft fan 561, a reformed gas cooling and shift assembly, and, a reformed gas CO2 removal assembly. The reformed gas cooling and shift assembly includes a heat exchanger 535, a high temperature shift 537, and heat exchangers 515, 539. The reformed gas CO2 removal assembly includes a heat exchanger 541, absorption tower 545, regeneration tower 549, a lean solution pump 555, and an air cooled heat exchanger 559.

The natural gas main 505 provides a path through the condensate knockout drum 506 and a compressor (not shown) for compressing the natural gas to 25 kg/cm2 (if necessary), and connects to a reformer fuel line 507 and a reform gas line 509. The reformer fuel line 507 supplies natural gas to the furnace of the reformer 503. The reform gas line 509 and a hydrogen recycle line 511 connect to a mixture line 513; the natural gas and hydrogen being referred to as a mixture. The recycle line 511 injects a small hydrogen stream into the natural gas for hydrogenation of any sulfur compounds .

The mixture line 513 provides a path through a heat exchanger 515 , a hydrogenation vessel 517 containing a cobalt-molybdenum catalyst , and a series of two desulfurization drums 519 , 521 filled with Zinc Oxide. The heat exchanger 515 heats said mixture to 370°C, where heat is transferred by cooling reformed gas exiting the reformer 503 .

A boiler (steam drum) 523 provides a source of steam superheated to 500°C through exchanger 524 and passed along a steam line 525 to feed into the mixture line 513. The mixture line 513 then passes through a heat recuperation section 527 of the reformer 503. The mixture line 513 includes a heat exchanger 529 which is heated by combustion gases vented through said heat recuperation section 527. The exchanger 524 is also heated through the venting combustion gases in the heat recuperation section 527.

The reformer 503 includes nickel catalyst filled furnace tubes which connect to the mixture line 513 to provide a path for the mixture to flow through the furnace section 531 of the reformer. The furnace of said reformer 503 includes a furnace box. Said furnace box includes two rows of vertically oriented reformer tubes; an insulated, airtight shell and burners. The burners provide the heat necessary to heat the gas and for the endothermic reforming reaction. Said burners are located inside said insulated, airtight shell and utilize natural gas for fuel from line 507. The nickel catalyst filled furnace tubes empty into a reformed gas line 533.

The reformed gas line 533 passes through a heat exchanger 535, a high temperature shift reactor 537 including an iron-chrome catalyst, heat exchanger 515 for preheating natural and hydrogen gas mixture, a heat exchanger 539 for heating boiler feed water, a heat exchanger 541 for cooling the reformed gas and boiling a rich carbonate solution, and into an absorption tower 545 containing a downflowing potassium carbonate solution for absorbing most of the CO2 from the reformed gas. The purified reformed gas exiting tower 545 is split by two lines, the recycle hydrogen line 511 and the hydrogen delivery line 547.

A regeneration tower 549 connects to said absorption tower 545, receiving carbonate solution including H2O and CO2 from tower 545 through line 551 and returning stripped carbonate solution to said tower 545 along line 553. Within the regeneration tower 549, carbonate solution is flashed at atmospheric pressure at the top of the regeneration tower 549 and boiled through said heat exchanger 541 to release CO2 and H2O. The stripped carbonate solution is pumped back towards the top of tower 545 through pump 555 and a portion of the carbonate solution is diverted through line 557 and an air cooled heat exchanger 559.

A forced draft fan 561 including suction filters connects to said heat recuperation section 527 through an exhaust line. The forced draft fan increases flow of rate of the exiting combustion gases across heat exchangers 563,565, 567, 569, 571, 524, 529 located in the heat recuperation section and develops a more even heat exchange across said heat recuperation section. Heat exchanger 563 Page not transmitted by the receiving

Office to the International Bureau at the time of publication

Steam (3) required to combine with the desulfurized natural gas is superheated to 500 degrees C into the heat recuperation section 527. The desulfurized natural gas is combined with said superheated steam in a ratio of 3.3 moles of steam per mole of natural gas. The combined stream (5) is then heated to 600°C (6) in the heat recuperation section 527 of the reformer 503 and is introduced into catalyst filled furnace tubes inside the furnace section 531. The gases are heated to 825°C as they pass down the tubes and the reforming reaction is catalyzed by the nickel containing reformer catalyst to reach pre-specified gas composition levels (7).

The burners of the reformer furnace box use natural gas (18) to provide the heat necessary to heat the gas and for the endothermic reforming reaction. No purge gas is burnt in the reformer.

Combustion air for the burners is provided by a forced draft fan 575 located at grade. The air from the fan is passed through the heat recuperation section 527 of the reformer where it is preheated to about 300°C with the reformer combustion gases. By preheating combustion air in the reformer heat recuperation section 527, less reformer fuel (18) is required.

The forced draft fan 575 is equipped with suction filters to prevent the entrance of dust into the furnace. Dust pickup through the burners has been a serious problem with natural draft furnaces due to the quantity of dust present from ore and product handling. In this case, the dust is carried into the heat recuperation section 527 from the furnace section 531 where it plugs the fins of the finned tubes, causing a substantial loss of heat transfer capacity.

Referring to Figure 3, the combustion gases from the reformer burners are pulled through a heat recuperation system 527 which reduces the temperature of the combustion gases (14) from 970 to about 135°C by preheating feed streams for the reformer, preheat reactor air, and combustion air for the reformer burners. The combustion gases are moved by an induced draft fan 561 which exhausts the gases into a stack 583 that is shared with the reducing gas preheat furnace 711. Use of an induced draft fan 561 provides more precise draft control than is possible with natural draft furnaces. As the combustion gases pass from the reformer box to the induced draft fan, they exchange heat with the following process streams: 1. Preheat reactor air (13) (2d exchanger 571); 2. Steam and natural gas feed (5) (exchanger 529); 3. Steam (4) (superheat exchanger 524); 4. Preheat reactor air (1st exchanger 569); 5. Boiler feed water (Steam generation exchangers 565, 567); and, 6. Reformer combustion air (exchanger 563).

The combustion air and induced draft fans 575, 561 for the reformer and combustion air fans 745, 723 for the reducing gas furnace 711 are equipped with two electric motors using disengaging clutches. One motor will be connected to the plant emergency generator (not shown). Thus, both furnaces will remain online at normal capacity during a power failure.

The reformer 503 is operated at close to a stoichiometric combustion mixture of air (19) and natural gas (18) using an 02 analyzer which controls the air rate from the combustion air fan 575 automatically. As a result, the 02 level in the combustion gas (14) is low enough to allow the gas to be used as inert gas in the areas where inert blankets must be maintained. Part of the combustion gas from the induced draft fan 561 is sent to the utilities area for use as inert gas.

The reformed gas mixture (7) leaving the reformer tubes is cooled from 825°C to 370°C in an exchanger 535 which generates 25 kg/cm2 steam. The steam is delivered to the boiler 523 and used as the feed to the reformer 503 along with steam produced in the heat recuperation section 527. The cooled reformed gas (8) is passed through a high temperature shift (HTS) reactor 537 filled with an iron-chrome catalyst which further reacts the CO remaining in the reformed gas mixture with H2O to produce more H2 . The reaction is exothermic , which increases the exit agas temperature to 430°C.

The product gas (9) from the HTS reactor 537 is cooled to about 360°C in an exchanger 515 using incoming natural gas. The reformed gases (10) exiting the natural gas preheat exchanger 515 pass through a second exchanger 539 and are cooled to about 180°C by heating boiler feed water (20) for the reformer 503.

The reforming reaction which occurs in the reformer 503 and shift reactor 537 produces CO2. Since an excess of H2O is required for the reforming reaction, some H2O is still contained in the reformed gas. Both of these are oxidizing gases in the reactor system and must be largely eliminated from the reformed gas (11) in order that it be effective as a reducing gas. By removing the CO2 from the reformed gas to a low content (under 0.5%), the CO2 in the total reducing gas (27) can be maintained at the target value of about 3.5%, even at the higher recycle ratio used in the improved design.

The reformed gas exiting the BFW preheater exchanger 539 at about 180°C passes through a CO2 removal system which consists of a hot carbonate acid gas treating unit 543. The reformed gas (11) first enters an exchanger 541 where itreboils rich carbonate solution. It then passes through an absorption tower 545 where the gas is contacted by a downflowing potassium carbonate solution which absorbs most of the CO2 from the reformed gas. Water content of the reformed gas is also reduced by condensation. The lean carbonate solution is introduced to the absorption tower 545 at two points, which permits CO2 removal to under 0.5% in the purified reformed gas (25).

The rich carbonate solution, which contains CO2 and H2O removed from the reformed gas (11), is regenerated in a regeneration tower 549 by flashing the solution (17) to essentially atmospheric pressure at the top of the tower 549, and stripping the carbonate solution of CO2 and H2O by means of a reboiler (exchanger 541) at the bottom of the column. The regenerated, or lean, solution is pumped out of the bottom of the regeneration tower 549 and back to the absorption tower 545. Part of the regenerated solution leaving the pump 555 is passed through an air cooled exchanger 559 to cool it.

The CO2 and H2O (17) liberated from the rich solution in the regeneration tower 549 is vented from the top of the regeneration tower 549. Both these components can be recuperated if desired. The reformed gas (25) exiting the CO2 removal system will contain about 3.5% H2O and 0.5% CO2. The Recycle Gas System

Referring to Figure 1, the recycle gas assembly 601 is comprised of a water cooled quench tower 603, or alternatively a waste heat boiler, which receives spent reducing gas from the reactor assembly 401 through pipe 453; a venturi scrubber 604; a line 605 which carries the cooled spent reducing gas from said quench tower 603 and through said venturi scrubber 604; a centrifugal compressor 615; a reducing gas preheater 711; an air forced draft blower 723; and, an induced draft fan 645. Line 605 is bled by lines 607,609 delivering a small stream of spent reducing gas along line 607 for burning in a reducing gas preheater 711 in the reducing gas supply assembly 701 and a small stream of gas along line 609 for use as a reactor purge gas. Line 607 is further fed by a natural gas supply through line 613. Line 609, prior to delivery in the reactor assembly 401, passes through a drier and compressor for drying the purge gas and compressing to 20 kg/cm2. Line 605 passes through a compressor 615 and then combines with reformed gas delivered along line 547 into line 717. Line 717 then passes through the reducing gas preheater 711 where line 717 connects with line 447.

The reducing gas preheater 711 includes a heat recuperation section 719 and a furnace section 721. The furnace in the furnace section 721 is fueled by line 607 and preheated combustion air is supplied through an air compressor 723 along line 725. In order to preheat the combustion air, line 725 passes through the heat recuperation section 719 and includes a heat exchanger portion 727. The flue gases exit the heat recuperation section 719 along line 729. Line 729 passes through an induced draft fan 745 and into a stack 583, where the gases are exhausted into the atmosphere.

The reducing gas preheater furnace 711 is of a similar construction to the reformer. It has a radiant box with vertical alloy tubes, a heat recuperation section 719, a combustion air forced draft blower 723, and an induced draft fan 745 which exhausts to the common stack 583. The use of a combustion air fan equipped with a filter eliminates the problem of dust buildup on the heat recuperator tubes. The Process for Recycling and Delivering ReducingGas

Again referring to Figure 1, the spent reducing gas (30) exiting the top reducing reactor still contains a substantial amount of H2, but due to the high water content resulting from the reduction reaction, the reducing power is Page not transmitted by the receiving

Office to the International Bureau at the time of publication

The streams which are heated in the heat recuperation section 719 are the total reducing gas (27) and the combustion air. The reducing gas is heated to about 500°C in the recuperation section and to 875°C in the radiant box. The amount of preheat of the combustion air depends upon the furnace design. The reducing gas preheater combustion gases are cooled to about 135°C in the heat recuperation section 719. The Briquetting Assembly

Referring to Figures 1 and 4, The briquetting assembly 801 is comprised of a pipe 803 which is fed reduced fines from line 445; an atmospheric storage drum 805 where pipe 803 deposits its cargo; three briquetter feed lines 811, 813, 815; three briquetting machines 817; three rotating trommels 819; a hot screener 823; a water filled tank 829; a product conveyor 833; a water quench tank 837; a fines and chips conveyor 841; and, a bucket conveyor 847. An alternate route for fines from the reactor assembly 401 is provided along line 443 which deposits the fines into a quench tank 807. Said storage drum 805 may in turn dump its contents into the quench tank 807 through line 809 or send its contents along lines 811, 813, 815 to three briquetting machines, respectively, (where only one briquetter 817 is shown for clarity). Lines 811, 813, 815 include cycling slide valves for metering the flow of fines to the briquetters.

A small feed drum is located on top of each of the briquetters 817 where the lines 811, 813, 815 deposit their respective loads. A helical feed screw forces fines between two counter-rotating rolls equipped with briquette shaped molds. One roll is fixed in place, while the other is compressible against the fixed roll with hydraulic cylinders. A rotating trommel 819 is located under the briquetters 817 for breaking strings of briquettes into individual units. A pipe 821 connects the exit port of the trommel 819 to the entry of a hot screener 823 located beneath the trommel. The screener 823 includes two screens 825, 827 for separating briquettes, chips, and fines. Screen 825 is a 1/2" screen and separates the briquettes from the fines and chips. The briquettes and large chips are able to slide and roll off the screen 823 and into a quench tank 829 including a discharge conveyor 831. The discharge conveyor 831 provides a path from the quench tank 829 and to a product conveyor 833. The product conveyor 833 provides a path to a briquette storage pile 835.

Screen 827 is located beneath screen 825 for receipt of smaller chips and fines and is comprised of a 1/2" grating. Of the smaller chips and fines, the larger chips are able to slide off the screen 827 and into a quench tank 837 including a discharge conveyor 839. The discharge conveyor 839 provides a path from the quench tank 837 and to a product conveyor 841. The product conveyor 841 provides a path to a chip storage pile 843. Smaller chips and fines fall through screen 827 where a conveyor 845 provides a path to a bucket conveyor 847. The bucket conveyor provides a path to the storage drum 805.

The entire briquetting assembly 801 through to the quench tanks 829, 837 is enclosed and maintainable under a positive pressure. Inert gas may be funneled into the briquetting assembly atmosphere in order to reduce potential oxidation. The Process for Brignetting

Referring to Figures 1 and 4, the hot reduced iron ore fines (36) must be briquetted in order to make a product that is resistant to reoxidation in storage and that can be easily handled and charged in steelmaking operations. The hot, reduced ore fines are transported from the bottom reducing reactor 407 to an atmospheric storage drum 805 which feeds the three briquetting machines 817.

The drum 805 is located directly above the lowest reducing reactor 407 which allows the briquetting machines 817 to be incorporated into the reactor structure, resulting in a more compact plant layout. The three briquetting machines 817 are designed so that each can handle slightly more than half the design plant capacity, which allows one machine to be shut down for maintenance at all times.

The reduced fines are metered from the storage drum 805 into the briquetting machines 817 through three feed lines 811, 813, 815 which each have a cycling slide valve to maintain flow control to the respective briquetting machines 817. The fines enter a small feed drum on top of the briquetting machine, and are forced between two counter-rotating rolls by a helical feed screw. The rolls are equipped with briquette shaped molds which compress the fines into briquettes. The compaction is achieved by a combination of the high pressure between the rolls and the high temperature of the fines, which makes them more compressible. The pressure is maintained by means of hydraulic cylinders that exert force against one of the two rolls. One roll is fixed and the other is allowed to move, which prevents roll breakage should a piece of metal pass through the machine.

The briquettes exit the machine 817 in a single string and are separated into individual briquettes in a rotating trommel 819. The individual briquettes, and fines and chips resulting from the trommel operation, leave the trommel in a combined stream and are separated in a hot screener 823 located below the trommels 819.

The briquetting machines 817 and trommels 819 are oriented so that the trommel discharges are in close proximity. This allows the briquettes (37) and fines/chips (38) to be transported to the screener 823 via metallic pipes which avoids the use of vibrating conveyors.

The hot screener 823 separates the briquettes from the fines and chips on two screens 825, 827. First, the product briquettes (37) are separated off on a 1/2" screen 825 and are quenched in a water filled tank 829 to 100 degrees C. The briquettes are discharged onto a product conveyor 833 where they are dried by the heat remaining in the briquette.

The fines and chips passing through the 1/2" screen 825 are further separated on a 1/4" screen 827. The chips between 1/2" and 1/4" removed on the screen are quenched in a water quench tank 837 and are discharged in a pile 843 by conveyor 841. This material is suitable for sale as a byproduct. The fine fraction under 1/4" passing through the screen 827 is recycled to the briquetters 817 via a bucket conveyor 847. The chips quench tank 837 is used to quench fines when they are not being recycled.

The entire briquetter system from the briquetter enclosure to the quench tanks 829, 837 is blanketed with inert gas under a slightly positive pressure. The inert gas has been treated to remove most of the CO2 in order to reduce the oxidation potential of the gas.

Line 443 equipped with a cycling slide valve is provided between the briquetter feed drum 805 and the reactor quench drum 807 in order to allow fines to be dumped when the briquetters are starting up or shutting down. The Utilities Assembly (System) and Process

The utilities assembly is comprised of a boiler feed water treating assembly; a machinery cooling water assembly; a process cooling water assembly; a package water assembly;a chilled water assembly; an inert gas cleanup and compression assembly; a forced air assembly; and, a backup electricity assembly.

In the boiler feed water treating assembly, boiler feed water is received from the industrial water main and is treated in sand and carbon filters prior to passing through deionizers. After the deionizers, the water is combined with the returning condensate from the generator steam turbine condenser and pumped to a deaerator where it is heated to 110°C with low pressure steam to drive off 02. The water can be further treated with hydrazine if required. The deaerator has a 1/2 hour inventory to allow operation during short term power failures.

In the machinery cooling water assembly, machinery cooling water is used to cool machinery in the process and to provide coolant in heat exchangers. The water is pumped to the users from the CCW sump and returns at a temperature of about 70°C. The water is cooled in a close heat exchange system to avoid contamination of the water by dust.

In the process cooling water assembly, process cooling water is required for cooling process gas streams and for scrubbing dust from process gas streams and from gases pulled through the dust collectors. The water returning from the various users goes to two primary and one secondary settling ponds where fine particles settle out, aided by a flocculant. The water is also cooled to about 60°C in the ponds. Two ponds are provided so that they can be cleaned on the run. Cooled water from the ponds is pumped to an evaporative type cooling tower where the water is cooled to about 30°C. Water is pumped from the sump to the users.

In the package water assembly, a package boiler is provided for driving the steam turbine generator, for plant steam, and for fluidization steam for the preheat reactor during a power outage. The boiler can also provide inert gas from the flue instead of using flue gas from the reformer if required.

In the chilled water assembly, a refrigerant type water chiller is provided to chill a small amount of cooling water to about 10°C. This chilled water is required for drying purge gas and instrument air.

In the inert gas cleanup and compression assembly, combustion gas from the reformer is cooled and dried using cooling water. The gas is compressed in one of two compressor lines to about 20 kg/cm2 and is passed through a small column where it is contacted with lean potassium carbonate solution. The CO2 content is reduced from about 13% to under 1% . The gas is then dried using chilled cooling water and sent on to the briquetting and reactor area for use in purges and to blanket the briquetting machines . A small amount of inert gas is compressed to 100 kg/cm2 and stored in tanks to be used for blasting plugged purges .

In the forced air assembly, instrument and utility air is provided by one of two electric motor driven compressors. The instrument air is dried using chilled water and dessicant. The instrument air is backed up by the 100 kg/cm2 inert gas storage tanks via a pressure letdown valve. in the backup electricity assembly, a condensing steam turbine driven electric generator provides sufficient power during power failures for the services listed below. Each of the pumps and compressors in the list has two 100% capacity units: one with electric motor drive hooked to the main supply and the other electric motor hooked to the generator. The fans are single units with two electric motor drives. The generator is in continuous service and provides power or backup power to the following: 1. Emergency plant lighting; 2. UPS backup; 3. Fire water pump; 4. One inert gas compressor; 5. One air compressor; 6. One BFW treating pump; 7. One BFW feed pump; 8. One machinery cooling water pump; 9. One process cooling water pump; 10. All four fans on the furnaces; and, 11. One BFW circulation pump (reformer).

The condensate from the condensing turbine is returned to the boiler feed water treating area for reuse.

Optionally, a gas turbine generator with steam generation by the exhaust gas can be used in place of the boiler with steam turbine driven electric generator.

STATE TABLES The following represents a compilation of the states of the various flow groups throughout the plant system. Numerals in parentheses ( ) are used to identify flow group, state, and makeup at each location throughout the plant.

Claims

What is claimed is : APPARATUS CLAIMS : 1. A processing plant for reducing finely divided iron oxide material in a circulating fluidized bed, comprising

an ore feed assembly ;

a reactor assembly;

reducing gas source means f or providing pressurized reducing gas ;

said reducing gas source means including reducing gas recycling means ;

inert gas source means for supplying a flow of inert gas ; said ore feed assembly including

temporary storage means for temporarily storing incoming iron ore;

ore feed conduit means for transferring dry iron ore from said ore feed assembly to said reactor assembly; said ore feed conduit means including first isolation valve means for maintaining steady flow of fines; and,

pressurizing means for pressurizing said ore feed conduit means; said reactor assembly including

preheat means for preheating said fines to a pre-determined reaction temperature and removing entrained water from said fines;

said preheat means including preheat ore inlet means and preheat ore outlet means;

said preheat ore inlet means connecting to said ore feed conduit means;

said preheat ore outlet means including cycling slide valve means for maintaining constant solids flow from said preheat means;

multiple ore reactors;

said multiple ore reactors including an uppermost reactor and a lowermost reactor;

each of said multiple ore reactors being located in graduated, decreasing height from said uppermost to said lowermost reactor; and,

reactor conduit means for connecting flow of fines downward and flow of reducing gas upward to and from each of said multiple ore reactors in series relation;

said uppermost reactor including

reducing gas outlet means for permitting flow of reducing gas out of said uppermost reactor and connecting to said reducing gas recycling assembly; and,

ore inlet means for permitting flow of fines into said uppermost reactor and connecting to said preheat ore outlet means;

said lowermost reactor including

reducing gas inlet means for permitting flow of reducing gas into said lowermost reactor and connecting to said reducing gas source means; and,

ore outlet means for permitting flow of fines out of said reactor assembly; said ore outlet means including second isolation valve means for maintaining steady flow of fines;

said ore outlet means and said ore feed conduit means connecting to said inert gas source means to prevent air from being carried with said fines into or out of said multiple ore reactors;

each of said multiple ore reactors including means for providing an evenly distributed, updraft of reducing gas through downward falling iron ore fines resulting in the development of a fluidized bed of said fines;

means for exhausting reducing gases exiting said fluidized bed; said means for exhausting including at least one pair of primary cyclones; said pair of primary cyclones removing entrained iron ore fines from exiting flue gases; said cyclones including externally actuated valve means for sealing off the cyclones in the event said cyclones become plugged with iron ore fines; and,

means for returning fines from said cyclones to said fluidized bed. 2. The processing plant as recited in claim 1, said ore feed assembly including

an ore preparation means for drying free water and separating oversize ore from said fines. 3. The processing plant as recited in claim 1, said preheat means comprising

a preheat reactor;

said preheat reactor including an upper reaction chamber, a lower reaction chamber, and a combustion chamber means for combusting of combustion gas and for heating said fines;

said upper reaction chamber downwardly connected to said lower reaction chamber;

said combustion chamber means being situated within said lower reaction chamber;

said preheat ore inlet means connecting to said upper reaction chamber;

said preheat ore outlet means connecting to said lower reaction chamber permitting a downward gravimetric flow of fines into said upper reaction chamber and out said lower reaction chamber;

combustion gas inlet means for connecting to said lower reaction chamber;

said flue gas outlet means connecting to said upper reaction chamber permitting an upward flow of flue gas into said lower reaction chamber and out said upper reaction chamber;

said fines and flue gas being mixable within said upper and lower reaction chambers to develop a fluidized bed;

separator means connected to the upper reaction chamber for separating the entrained fines from said flue gas;

recycling conduit means extending from said separator means to said lower chamber and providing a conduit for returning de-entrained fines to the said flow of fines; and,

fluidizing gas source means for supplying flue gas to said flue gas inlet means. 4. The processing plant as recited in claim 1, said processing plant including

a quench and gas cleanup assembly;

said preheat means including flue gas inlet means and flue gas outlet means;

said quench and gas cleanup assembly connecting to said flue gas outlet means;

said quench and gas cleanup assembly comprising gas cooling means for cooling exiting flue gases, scrubber means for scrubbing exiting gases, and

venting means for venting exiting gases; and, said venting means including pressure letdown valve means and at least one stack, said exiting gases being de-pressurized by said pressure letdown means and then released through said stack. 5. The processing plant as recited in claim 1, each of said multiple reactors including

an upper reaction chamber downwardly connected to a lower reaction chamber,

separator means connected to the upper reaction chamber for separating entrained fine ore particles from the circulating flluidized bed,

a recycling conduit means extending from said separator means to the lower reaction chamber and providing a conduit for returning de-entrained fines to the main flow of iron ore fines. 6. The processing plant as recited in claims 3 or 5, said separator means comprising

a cyclone separator. 7. The processing plant as recited in claim 1, said processing plant including

briquetting means for compressing and molding reduced fines into briquettes;

said briquetting means connecting to said ore outlet means. 8. The processing plant as recited in claim 1, said reducing gas source means including

natural gas source means for providing natural gas;

re f ormation means f or producing hydrogen reducing gas from said natural gas ;

said reformation means including a natural gas furnace ;

heat recuperation means for recovering heat from said natural gas furnace and utilizing heat to preheat oxygen, hydrogen, and natural gas utilized in said reactor assembly. 9. The processing plant as recited in claim 1, said processing plant producing a 90+% metallization product. Ore Preparation Assembly 10. In a processing plant for reducing wet iron ore fines under 1/2", an ore preparation assembly comprising:

an ore feed loading hopper;

a drier feed bin;

an ore drier;

a splitter hopper including a diverter gate;

multiple main feed bins including level probes; means for conveying fines from said ore feed loading hopper to said drier feed bin;

transport means for conveying the fines from said drier feed bin, through said ore drier and said splitter hopper and to said multiple main feed bins;

ore feed delivery means for delivering iron ore fines from said multiple main feed bins to a subsequent stage of the processing plant;

said diverter gate providing a means for diverting fines into each of the respective multiple main feed bins;

said drier feed bin including a drier weigh feeder;

said drier weigh feeder providing a constant, adjustable ore fine feed rate to said ore drier;

said multiple main feed bins including at least two main feed bins; and, said multiple main feed bins having a storage capacity of 10-12 hour inventory of fines. 11. The assembly as recited in claim 10, said ore drier comprising

a rotary kiln drier. 12. The assembly as recited in claim 10, said drier burning natural gas in a stream of air provided by a blower. 13. The assembly as recited in claim 10, said drier drying the fines to a free water content of under 0.2% and a temperature of 100-110°C. 14. The assembly as in claim 10, said ore feed delivery means comprising

variable speed feed conveyors individually capable of supplying up to 120% of design ore feed rate to the reactor circuits. Ore Feed Assembly: 15. In a processing plant for reducing iron ore fines under 1/2" including an ore preparation assembly with an ore feed delivery means and a reactor assembly with a top entrance, an ore feed assembly comprising:

controller means for controlling the flow of incoming iron ore from said ore feed delivery means;

ore feed conduit means for transferring iron ore from said ore feed delivery means to said reactor assembly; and,

pressurizing means for pressurizing said ore feed conduit means.

16. The assembly as recited in claim 15, said ore feed conduit means including

temporary storage means for temporarily storing incoming iron ore from said ore feed delivery means. 17. The assembly as recited in claim 16, said temporary storage means including

a lockhopper surge bin. 18. The assembly as recited in claim 17, said lockhopper surge bin being located at the top entrance of said reactor assembly. 19. The assembly as recited in claim 17, said controller means including

level probe means for controlling the speed of said ore feed delivery means;

said level probe means being situated within said lockhopper surge bin in order to maintain surge bin levels within a pre-determined range. 20. The assembly as recited in claim 15, said ore feed conduit means including

a charge development system. 21. The assembly as recited in claim 20, said charge development system including:

a weigh bin;

lockhopper charge conveyor means for conveying fines from said lockhopper surge bin to said weigh bin; weighing means for weighing said weigh bin and an ore charge, said weighing means comprising multiple load cells, said weigh bin being located on said multiple load cells;

multiple ore feed assemblies;

diverter valve means for directing fines to one of said multiple ore feed assemblies, said diverter valve means being located below said weigh bin;

said multiple ore feed assemblies comprising a pair of reactor ore feed assemblies in parallel;

each of said pair of reactor ore feed assemblies being designed to meet a pre-specified reactor feed rate in order that one of said pair of reactor ore feed assemblies may deliver said feed rate in the event of mechanical failure;

each of said multiple reactor ore feed assemblies including an upper lockhopper and a lower lockhopper in series;

each of said lockhoppers comprising a conical pressure vessel and a material inlet valve;

each pair of upper and lower lockhoppers in series including a common valve means and a pressurizing port;

said weigh bin being located above the upper lockhopper;

said upper inlet valve means for closing said conical pressure vessel;

said pressurizing means connecting to said pressurizing port;

said upper and lower conical pressure vessels of each pair of upper and lower lockhoppers in series being pressurizable by said pressurizing means to a pre-determined reactor pressure;

where the pressure of said upper to lower vessels is equalized, ore may be transferred by said common valve means from the upper to the lower vessel; and, upon completion of transfer, said common valve means may be closed, the upper vessel de-pressurized, and the upper inlet valve opened to await another charge. 22 . The assembly as recited in claim 21 , said controller means automatically shutting down said lockhopper charge conveyor means upon delivery of a pre-specified charge of fines to said weigh bin. 23 . The assembly as recited in claim 15 , said ore feed conduit means including

isolation valves . Preheat Reactor Assembly 24 . In a processing plant for reducing wet iron ore fines under 1/2 " including a reactor assembly with a preheat reactor assembly and a stage subsequent to the preheat reactor assembly , and, an ore feed assembly with a pressurized ore feed conduit means for transferring iron ore from said ore feed delivery means to said reactor assembly , said preheat reactor assembly comprising:

a preheat reactor;

a quench and gas cleanup system;

an airstream source means for providing an airstream;

a natural gas source means for providing natural gas; said preheat reactor including:

a reactor vessel including an upper cavity portion and a lower cavity portion;

ore inlet port means for connecting said upper cavity portion to the ore feed delivery means;

gaseous exhaust port means for connecting said upper cavity portion to said quench and gas cleanup system;

ore outlet port means for providing an exit for ore fines from said lower cavity portion and out of said preheat reactor;

air intake port means connecting said lower cavity portion to said airstream source means and facilitating the development of an airstream upward from the lower cavity portion to the upper cavity portion and out of the gaseous exhaust port means;

said airstream passing through falling iron ore fines and developing a fluidized bed of iron ore fines within said reactor vessel;

said air intake port means being located below said ore outlet port means;

natural gas injection means for injecting natural gas into said airstream and for igniting said natural gas in said airstream;

said natural gas injection means including natural gas intake port means connecting said lower cavity portion to said natural gas source means; and,

combustion air means for providing combustion air and mixing combustion air with said natural gas to facilitate combustion, said mixture being referred to as flue gas. 25. The preheat reactor assembly as recited in claim 24, said preheat reactor being pressurized. 26. The preheat reactor assembly as recited in claim 24, said preheat reactor assembly including

airstream distribution means for developing an evenly distributed, upflowing airstream across the cross-section of said reactor vessel; said airstream distribution means being located between the air intake port means and the ore outlet port means in the lower cavity portion. 27. The preheat reactor assembly as recited in claim 24, said airstream distribution means including

a gas distribution grid. 28. The preheat reactor assembly as recited in claim 27, said gas distribution grid comprising

heat resistant alloy. 29. The preheat reactor assembly as recited in claim 24, said airstream distribution means comprising

a flat perforated circular plate;

a vertical cylinder comprising thin plate steel; and,

multiple vertical, small diameter tubes;

the outside diameter of said vertical cylinder in abutting relation with the inside diameter of said reactor vessel;

said vertical cylinder being seated in the bottom of said lower cavity portion and having an upward facing portion;

said flat perforated circular plate being slightly smaller in diameter than the inside diameter of said reactor vessel;

said flat perforated circular plate being fixed to said upward facing portion of the vertical cylinder;

said vertical, small diameter tubes jutting through perforations in said flat perforated circular plate and being fixed to said flat perforated circular plate;

said flat perforated circular plate being supported centrally by said vertical, small diameter tubes; said airsteam being forced into and directed upward through said vertical, small diameter tubes. 30. The preheat reactor assembly as recited in claim 29, said flat perforated circular plate having

an evenly distributed series of perforations across its cross sectional area producing an evenly distributed upward air flow across the cross sectional area of said preheat reactor as flue gas is delivered into said lower cavity portion and forced through said vertical, small diameter tubes. 31. The preheat reactor assembly as recited in claim 24, said preheat reactor assembly including

ore and gas separating means for separating entrained ore fines from gases exiting said gaseous exhaust port means and returning de-entrained ore fines to the mainstream flow of iron ore fines prior to said ore outlet port means;

said ore and gas separating means being located within said upper cavity portion and in front of said gaseous exhaust port means. 32. The preheat reactor assembly as recited in claim 31, said ore and gas separating means including

pairs of primary and secondary cyclones. 33. The preheat reactor assembly as recited in claim 32, said cyclones including

externally actuated valve means for sealing off the cyclones in the event said cyclones become plugged with iron ore fines.

34. The preheat reactor assembly as recited in claim 32, said cyclones comprising

heat resistant alloy. 35. The preheat reactor assembly as recited in claim 24, said ore outlet port means including

a refractory lined ore pipe;

said refractory lined pipe including cycling slide valve means for maintaining constant solids flow from said preheat reactor;

said refractory lined ore pipe connecting to a subsequent stage of the reactor assembly. 36. The preheat reactor assembly as recited in claim 35, said preheat reactor assembly including

inert gas source means for supplying a flow of inert gas into said refractory lined ore pipe and into the preheat reactor preventing air from being carried to a subsequent stage of the reactor assembly. 37. The preheat reactor assembly as recited in claim 24, said gaseous exhaust port means including multiple gas outlet pipes and a refractory lined gas outlet pipe;

said multiple gas outlet pipes connecting to said refractory lined gas outlet pipe;

said refractory lined gas outlet pipe connecting to said quench and gas cleanup system. 38. The preheat reactor assembly as recited in claim 37, said ore and gas separating means including cyclones;

said cyclones being positioned in front of said multiple gas outlet pipes. 39. The preheat reactor assembly as recited in claim 24, said quench and gas cleanup system including

gas cooling means for cooling exiting gases;

scrubber means for scrubbing exiting gases;

venting means for venting exiting gases;

said venting means including pressure letdown valve means for depressurizing exiting gases and at least one stack for releasing exiting gases; and,

conduit means connecting said gas cooling means, said scrubber means, and said venting means. 40. The preheat reactor assembly as recited in claim 24, said combustion air means including

a centrifugal air compressor;

said centrifugal air compressor including

suction filters to eliminate dust; and water cooled intercoolers to remove the heat of compression. 41. The preheat reactor assembly as recited in claim 40, said centrifugal air compressor compressing combustion air to about 13-14 kg/cm2. 42. The preheat reactor assembly as recited in claim 1, said combustion air means including

means for preheating combustion air to approximately 700-750 degrees C. 43. The preheat reactor assembly as recited in claim 42, said means for preheating combustion air including

a reformer heat recuperator system. 44. The preheat reactor assembly as recited in claim 24, said natural gas injection means comprising

a series of burners located within said lower cavity portion and about the circumference of said reactor vessel. 45. The preheat reactor assembly as recited in claim 44, said preheat reactor including a gas distribution means located within said lower cavity portion;

said natural gas injection means located above said gas distribution means. 46. The preheat reactor assembly as recited in claim 45, said natural gas injection means being located about 1 meter above the gas distribution means. 47. The preheat reactor assembly as recited in claim 24, said natural gas injection means in combination with said combustion air means maintaining an air to gas ratio of about 2% O2 mixing with the natural gas, the combination thereof being referred to as flue gas. 48. The preheat reactor assembly as recited in claim 44, said preheat reactor including

burner de-plugging means for preventing plugging of said burners. 49. The preheat reactor assembly as recited in claim 48, said burner de-plugging means including a purge gas injected through said burners. 50. The preheat reactor assembly as recited in claim 49, said purge gas comprising

steam. 51. The preheat reactor assembly as recited in claim 49, said purge gas being injectable when natural gas flow is low. 52. The assembly as recited in claim 24, said preheat reactor comprising

a carbon steel shell and a dual insulation and refractory layer;

said dual insulation and refractory layer internally lining said carbon steel shell. Reactor Assembly: 53. In a processing plant for reducing wet iron ore fines under 1/2" including a reactor assembly and an ore feed assembly with a pressurized ore feed conduit means for transferring iron ore from said ore feed delivery means to said reactor assembly, said reactor assembly comprising:

multiple reactors including an uppermost reactor and a lowermost reactor; each of said multiple reactors being positioned in graduated, decreasing height from said uppermost to said lowermost reactor;

a reducing gas source means for providing a supply of reducing gas into said lowermost reactor;

ore path means for establishing a path for flow of fines to and from each of said multiple reactors in order of graduated, decreasing height from said uppermost to said lowermost reactor;

reducing gas path means for establishing a path for flow of reducing gas to and from each of said multiple reactors in order of graduated, increasing height from said lowermost to said uppermost reactor;

said multiple reactors and said ore path means establishing a gravity path for the flow of ore fines;

said pressurized ore feed conduit means connecting to said uppermost reactor.

54. The reactor assembly as recited in claim 53, said reactor assembly including

a preheat reactor;

said preheat reactor being positioned above said uppermost reactor and connecting in series between said pressurized feed conduit means and said uppermost reactor. 55. The reactor assembly as recited in claim 53, each of said multiple reactors including:

a reactor vessel including an upper cavity portion and a lower cavity portion;

ore inlet port means for providing an entrance for ore fines into said upper cavity portion;

gas exhaust port means for providing an exit for exhaust gas from said upper cavity portion;

ore outlet port means for providing an exit for ore fines from said lower cavity portion;

gas intake port means for providing an entrance for reducing gas into said lower cavity portion;

said gas intake port means and said gas exhaust port means facilitating the development of a flowstream of reducing gas upward through said reactor vessel;

said flowstream passing through a downward flow path of iron ore fines and facilitating the development of a fluidized bed of iron ore fines within said reactor vessel. 56. The reactor assembly as recited in claim 55, said gas intake port means being located below said ore outlet port means. 57. The reactor assembly as recited in claim 53, said ore path means comprising

multiple refractory lined pipes. 58. The reactor assembly as recited in claim 53 , said ore path means including

cycling slide valve means for maintaining constant solids flow from said preheat reactor. 59. The reactor assembly as recited in claim 53 , said reducing gas path means comprising

multiple refractory lined pipes . 60. The reactor assembly as recited in claim 53 , said multiple reactors being pressurized. 61. The preheat reactor assembly as recited in claim 55, each of said multiple reactors including

flowstream distribution means for developing an evenly distributed, upflowing flowstream across the cross-section of said reactor vessel;

said flowstream distribution means being located above said gas intake port means. 62. The reactor assembly as recited in claim 61, said flowstream distribution means being located between said gas intake port means and said ore outlet port means. 63. The reactor assembly as recited in claim 61, said flowstream distribution means including

a gas distribution grid.

64. The reactor assembly as recited in claim 63, said gas distribution grid comprising heat resistant alloy. 65. The reactor assembly as recited in claim 61, said flowstream distribution means comprising

a flat perforated circular plate;

a vertical cylinder comprising thin plate steel; and,

multiple vertical, small diameter tubes;

said vertical cylinder being seated in the bottom of said lower cavity portion- and having an upward facing portion;

said flat perforated circular plate being supported centrally by said vertical, small diameter tubes ;

said flowsteam being forced into and directed upward through said vertical , small diameter tubes . 66. The reactor assembly as recited in claim 65, said flat perforated circular plate having

an evenly distributed series of perforations across its cross-sectional area producing an evenly distributed upward flow of reducing gas across the cross-sectional area of each of said multiple reactors as reducing gas is delivered into said lower cavity portion and forced through said vertical, small diameter tubes. 67. The reactor assembly as recited in claim 55, each of said multiple reactors including

ore and gas separating means for separating entrained ore fines from gases exiting said gas exhaust port means and returning de-entrained ore fines to the mainstream flow of iron ore fines prior to said ore outlet port means;

said ore and gas separating means being located within said upper cavity portion and in front of said gas exhaust port means. 68. The reactor assembly as recited in claim 67, said ore and gas separating means including

pairs of primary and secondary cyclones. 69. The reactor assembly as recited in claim 68, said cyclones including

externally actuated valve means for sealing off the cyclones in the event said cyclones become plugged with iron ore fines. 70. The reactor assembly as recited in claim 68, said cyclones comprising

heat resistant alloy. 71. The reactor assembly as recited in claim 53, said reactor assembly including

inert gas source means for supplying a flow of inert gas into said ore path means and said multiple reactors to reduce oxidizing effects. 72. The reactor assembly as recited in claim 53, said reactor assembly including

a gas recycling system connecting to said gas path means . 73. The reactor assembly as recited in claim 72, said reducing gas path means including

multiple gas outlet pipes and a refractory lined gas outlet pipe;

said refractory lined gas outlet pipe connecting to said gas recycling system. 74. The reactor assembly as recited in claim 55, said reactor assembly including

a gas recycling system connecting to said gas path means. 75. The reactor assembly as recited in claim 74, said reducing gas path means including

multiple gas outlet pipes and a refractory lined gas outlet pipe;

said multiple gas outlet pipes having a first end connecting to said gas exhaust port means of said uppermost reactor and a second end connecting to said refractory lined gas outlet pipe;

said refractory lined gas outlet pipe connecting to said gas recycling system. 76. The reactor assembly as recited in claim 73, said reactor assembly including

ore and gas separating means;

said ore and gas separating means including cyclones ; said cyclones being positioned in front of said multiple gas outlet pipes. 77. The reactor assembly as recited in claim 72, said gas recycling system including

scrubber means for scrubbing exiting reducing gas;

compressor means for re-pressurizing exiting reducing gas;

heater means for heating reducing gas; and, recycling conduit means connecting said scrubber means, said scrubber means and said heater means in series. 78. The reactor assembly as recited in claim 77, said recycling conduit means including

gas intake connecting means for connecting to said lowermost reactor;

gas exhaust connecting means for connecting to said uppermost reactor. 79. The reactor assembly as recited in claim 77, said heater including

a reformer heat recuperator system. 80 . The reactor assembly as recited in claim 77 , said gas recycling system including

reducing gas source connector means f or connecting said reducing gas source means to said recycling conduit means . 81. The assembly as recited in claim 53, each of said multiple reactors including

a carbon steel shell; and,

a dual insulation and refractory layer; said dual insulation and refractory layer internally lining said carbon steel shell. REDUCING GAS PREPARATION ASSEMBLY 82. In a processing plant for reducing wet iron ore fines under 1/2", a reducing gas preparation assembly for production of reducing gas comprising:

a natural gas source means for supplying natural gas to said reducing gas preparation assembly;

drier means for removing condensate from said natural gas;

compressor means for compressing the natural gas to 25 kg/cm2;

first heat exchanger means for heating said natural gas;

sulfur removal means for removing sulfur from said natural gas and creating a gas mixture;

steam source means for developing and delivering steam for said reducing gas preparation assembly;

steam mixing means for mixing cold steam with said gas mixture developing a steam and gas mixture;

second heat exchanger means for heating said steam and gas mixture;

first catalyzing means for catalyzing reactions in said steam and gas mixture developing hydrogen gas and creating a reformed gas mixture in an endothermic reaction;

third heat exchanger means for cooling said reformed gas mixture;

second catalyzing means for catalyzing reactions of CO with H2O in said reformed gas mixture to develop additional hydrogen gas in an exothermic reaction;

fourth heat exchanger means for cooling said reformed gas mixture; CO2 removal means for absorbing CO2 from said reformed gas, condensing H2O from said reformed gas, and developing said reducing gas; and,

path means for developing a path for gas to pass through each of the aforenamed means in series. 83. The reducing gas preparation assembly as recited in claim 82, said first heat exchanger using reformed gas to heat incoming natural gas. 84. The reducing gas preparation assembly as recited in claim 82 , said drier means comprising

a condensate knockout drum. 85. The reducing gas preparation assembly as recited in claim 82, said sulfur removal means including

a source means for injecting a small hydrogen stream into the natural gas for hydrogenation of any sulfur compounds. 86. The reducing gas preparation assembly as recited in claim 85, said sulfur removal means comprising

a first vessel;

said first vessel including a cobalt-molybdenum catalyst means for promoting the reaction of non-H2S compounds with H2 to form H2S compounds. 87. The reducing gas preparation assembly as recited in claim 85, said sulfur removal means comprising

a second and third vessel;

said second and third vessels being connected in series and including ZnO;

said ZnO reacting with H2S compounds in said natural gas; and, said reacted compounds being removable from said natural gas. 88. The reducing gas preparation assembly as recited in claim 82, said first catalyzing means comprising

a furnace means;

said furnace means including reformer tubes through which said steam and gas mixture is forced;

said reformer tubes include nickel catalyst means for catalyzing hydrogen gas reforming reactions. 89. The reducing gas preparation assembly as recited in claim 88, said furnace means including

at least two rows of vertically oriented reformer tubes;

an insulated, airtight shell;

forced draft fan means for providing combustion air;

natural gas injection means; and

burners;

said burners being located inside said insulated, airtight shell and utilizing natural gas for fuel. 90. The reducing gas preparation assembly as recited in claim 89, said furnace means including

combustion air pre-heat means for pre-heating combustion air prior to mixing with natural gas fuel. 91. The reducing gas preparation assembly as recited in claim 82, said steam source means including

boiler means;

a water source;

sump pump means for pumping boiler feed water from said water source to said boiler means. 92. The reducing gas preparation assembly as recited in claim 89, said furnace means including

heat recuperation means for transferring heat from gas exhaust to other flow paths;

said heat recuperation means including at least one heat exchanger means for transferring heat from said gas exhaust to another flow stream; and,

induced draft fan means for sucking gas exhaust through said heat recuperation means and over said at least one heat exchanger means. 93. The reducing gas preparation assembly as recited in claim 92, said processing plant including

a preheat reactor and reactor combustion air source means for supplying combustion air to said preheat reactor;

said heat recuperation means including reactor air heat exchanger means for preheating said combustion air supplied to said preheat reactor. 94. The reducing gas preparation assembly as recited in claim 92, said heat recuperation means including

superheated steam heat exchanger means for heating saturated steam supplied by said steam source means and developing superheated steam. 95. The reducing gas preparation assembly as recited in claim 92, said heat recuperation means including

said second heat exchanger means. 96. The reducing gas preparation assembly as recited in claim 92, said heat recuperation means including boiler feed water heat exchanger means for developing steam from boiler feed water,- said boiler feed water heat exchanger means integrating as a component of said steam source means. 97. The reducing gas preparation assembly as recited in claim 92, said induced draft fan means including

at least two electric motors;

each of said two electric motors including disengaging clutches. 98. The reducing gas preparation assembly as recited in claim 92, said processing plant including

a plant emergency power generator;

at least one of said two electric motors connecting to said plant emergency power generator. 99. The reducing gas preparation assembly as recited in claim 89, said forced draft fan means including

at least two electric motors;

each of said two electric motors including disengaging clutches. 100. The reducing gas preparation assembly as recited in claim 99, said processing plant including

a plant emergency power generator;

at least one of said two electric motors connecting to said plant emergency power generator. 101. The reducing gas preparation assembly as recited in claim 89, said furnace means including

an O2 analyzer and combustion air rate control means for maintaining approximately stoichiometric combustion mixture of combustion air and natural gas.

102. The reducing gas preparation assembly as recited in claim 89, said processing plant including

an inert gas source means;

said inert gas source means comprising exhaust gas from said furnace means. 103. The reducing gas preparation assembly as recited in claim 82, said second catalyzing means including

a high temperature shift reactor. 104. The reducing gas preparation assembly as recited in claim 82, said second catalyzing means including

an iron-chrome catalyst. 105. The reducing gas preparation assembly as recited in claim 82, said first heat exchanger means utilizing said reformed gas mixture as a heat source for heating natural gas. 106. The reducing gas preparation assembly as recited in claim 92, said steam source means including

boiler feed water heat exchanger means for preheating boiler feed water prior to reaching said boiler means;

said boiler feed water heat exchanger means transferring heat from said reformed gas mixture to said boiler feed water. 107. The reducing gas preparation assembly as recited in claim 82, said CO2 removal means including

a hot carbonate acid gas treating unit. 108. The reducing gas preparation assembly as recited in claim 82, said CO2 removal means including an absorption tower. 109. The reducing gas preparation assembly as recited in claim 108, said absorption tower including

potassium carbonate solution source means for providing a potassium carbonate solution to said absorption tower;

a flowpath means providing a downward flowpath for said potassium carbonate solution and an upward flowpath for said reformed gas mixture. 110. The reducing gas preparation assembly as recited in claim 109, said absorption tower including

means for introducing said potassium carbonate solution at least in two locations along said downward flowpath. 111. The reducing gas preparation assembly as recited in claim 82, said CO2 removal means effecting CO2 removal to under 0.5% of said reducing gas. 112. The reducing gas preparation assembly as recited in claim 109, said CO2 removal means including

a regenerator means for removing CO2 and H2O from said potassium carbonate solution. 113. The reducing gas preparation assembly as recited in claim 112, said regenerator means including

a regenerator tower;

said regenerator tower being open to the atmosphere. 114. The reducing gas preparation assembly as recited in claim 113, said regenerator tower including

a reboiler means for stripping the carbonate solution of CO2 and H2O and developing a regenerated solution;

said reboiler being at the bottom of said absorption tower. 115. The reducing gas preparation assembly as recited in claim 113, said regenerator tower including

a pump means for pumping said regenerated solution back to said absorption tower. 116. The reducing gas preparation assembly as recited in claim 113, said CO2 removal means including

an air cooled exchanger means for cooling said regenerated solution before re-entry into said absorption tower. GAS RECYCLING ASSEMBLY 117. In a processing plant for reducing wet iron ore fines under 1/2" including a reactor assembly, a gas recycling assembly for recycling reducing gas exiting said reactor assembly comprising:

waste heat boiler means for removing heat and moisture from incoming used wet reducing gas by generating steam and developing a cooled recycle gas;

scrubber means for scrubbing said cooled recycle gas and developing a cooled and scrubbed recycle gas; and, compressor means for compressing said cooled and scrubbed recycle gas prior to re-delivery to said reactor assembly. 118. The gas recycling assembly as recited in claim 117, said waste heat boiler means comprising a waste heat boiler. 119. The gas recycling assembly as recited in claim 117, said waste heat boiler means comprising

a quench tower. 120. The gas recycling assembly as recited in claim 117, said waste heat boiler means being water cooled. 121. The gas recycling assembly as recited in claim 117, said scrubber means comprising

a venturi scrubber. 122. The gas recycling assembly as recited in claim 117, said gas recycling assembly including

a furnace means; and,

a diverter conduit means for diverting a small amount of dry reducing gas for burning in said furnace means. 123. The gas recycling assembly as recited in claim 122, said gas recycle assembly including

recycle gas drier and compressor means for drying and compressing said dry reducing gas prior to delivery to said furnace means. 124. The gas recycling assembly as recited in claim 117, said compressor means comprising

a centrifugal compressor. 125. The gas recycling assembly as recited in claim 117, said processing plant including

a gas preparation assembly for developing a supply of reducing gas ;

said gas recycling assembly inc luding reducing gas injection means for inj ecting reducing gas from said gas preparation assembly into said cooled and scrubbed recycle gas . 126. The gas recycling assembly as recited in claim 125, said cooled and scrubbed recycle gas being combined with said reducing gas in a ratio approximating 3.5:1. 127. The gas recycling assembly as recited in claim 117, said gas recycle assembly including

H2S injector means for injecting small quantities of H2S into said cooled and scrubbed recycle gas. 128. The gas recycling assembly as recited in claim 117, said gas recycling assembly including

conduit means for delivering said cooled and scrubbed recycle gas to said reactor assembly. 129. The gas recycling assembly as recited in claim 128, said conduit means comprising

a refractory lined pipe. 130. The gas recycling assembly as recited in claim 117, said gas recycling assembly including

reducing gas preheater means for preheating said cooled and scrubbed recycle gas prior to delivery to said reactor assembly. 131. The gas recycling assembly as recited in claim 130, said reducing gas preheater comprising

furnace means for burning a fuel and providing a source of hot exhaust gases; Page not transmitted by the receiving

Office to the International Bureau at the time of publication

131, said preheater including

combustion air forced draft blower means for blowing combustion air through said at least one gas flowpath means;

said at least one gas flowpath means connecting to said reactor assembly. BRIQUETTING ASSEMBLY 138. In a processing plant for reducing wet iron ore fines under 1/2", said processing plant including a reactor assembly with a lowest reducing reactor and a reactor structure and having a design processing plant briquette production capacity; a briquetting assembly comprising:

an atmospheric storage drum;

multiple briquetting machines;

conveyor means for transporting fines from said lowest reducing reactor to said atmospheric storage drum;

conduit means for providing a gravity flow path for fines travelling from said atmospheric storage drum to said multiple briquetting machines; said conduit means including a cycling slide valve means for metering flow of said fines from said atmosperic storage drum;

each of said multiple briquetting machines comprising a pair of counter-rotating parallel rolls and a small feed drum; said small feed drum being situated on top of said multiple briquetting machines for receiving said flow of said fines; said small feed drum including a forced feed means for forcing said flow of said fines between said pair of counter-rotating parallel rolls;

each of said pair of counter-rotating parallel rolls including briquette shaped molds;

said flow of said fines being compressed into briquettes .

139. The briquetting assembly as recited in claim 138, said atmospheric storage drum being located directly above the lowest reducing reactor. 140. The briquetting assembly as recited in claim 138, said multiple briquetting machines being enclosed within the reactor structure. 141. The briquetting assembly as recited in claim 138 , each of said multiple briquetting machines being designed to produce more than half the design processing plant briquette production capacity. 142. The briquetting assembly as recited in claim 138, high compaction of fines into briquettes being achieved by a combination of high pressure between said pairs of counter-rotating parallel rolls and high temperature of said flow of said fines imparted from said reactor assembly. 143. The briquetting assembly as recited in claim 138, each of said multiple briquetting machines including hydraulic means for maintaining pressure forcing one of said counter-rotating parallel rolls against the other of said counter-rotating parallel rolls. 144. The briquetting assembly as recited in claim 138, one of said counter-rotating parallel rolls being fixed and the other of said counter-rotating parallel rolls being movable. 145. The briquetting assembly as recited in claim 138, said briquetting assembly including

briquette separator means for separating briquettes and briquette path means for delivering said briquettes from said multiple briquetting machines to said briquette separator means. 146. The briquetting assembly as recited in claim 145, said briquette separator means comprising

a rotating trommel. 147. The briquetting assembly as recited in claim 138, said briquetting assembly including

screening means for separating briquettes from fines and chips, and, path means for providing a path for briquettes, fines and/or chips from said multiple briquetting machines to said screening means. 148. The briquetting assembly as recited in claim 147, said screening means comprising

a hot screener. 149. The briquetting assembly as recited in claim 147, said path means comprising

pipes. 150. The briquetting assembly as recited in claim 147, said screening means comprising

at least two differently sized screen portions. 151. The briquetting assembly as recited in claim 147, said screening means including

a first screen portion for screening briquettes from said fines and chips. 152. The briquetting assembly as recited in claim 138, said forced feed means including a helical feed screw. 153 . The briquetting assembly as recited in claim 138 , said briquette assembly including a quench tank for cooling briquettes . 154. The briquetting assembly as recited in claim 138 , said quench tank cooling briquettes to approximately 100 C. 155. The briquetting assembly as recited in claim 138, said briquette assembly including

a product conveyor means for conveying briquettes to a destination and drying the briquettes with the remaining heat. 156. The briquetting assembly as recited in claim 138, said briquette assembly including

a quench tank for cooling large chips;

said quench tank including an enclosed quench box, water sprays, a vent gas stack for dissipating hydrogen production, a water chamber situated below said quench box for receiving said large chips; and a flight separator for transporting said large chips to a destination. 157. The briquetting assembly as recited in claim 138, said briquette assembly including

conveyor means for conveying large chips to a destination. 158. The briquetting assembly as recited in claim 138 , said briquetting assembly including

a small chips recycle means for transporting said small chips to said multiple briquetting machines .

159. The briquetting assembly as recited in claim 158, said small chips recycle means comprising

a bucket conveyor. 160. The briquetting assembly as recited in claim 138, said processing plant including

a briquetter enclosure;

said briquetting assemby including inert gas blanket means for blanketing substantially all of said briquette assembly with inert gas. 161. The briquetting assembly as recited in claim 160, said inert gas being maintainable under a slight positive pressure. 162. The briquetting assembly as recited in claim 160, said inert gas including

a low C02 content. 163. The briquetting assembly as recited in claim 138, said briquette assembly including

a conduit line and a reactor quench drum;

said conduit line including a cycling slide valve;

said conduit line connecting said briquetter feed drum and said reactor quench drum permitting fines to be dumped when said multiple briquetting machines are starting up or shutting down. 164. The briquetting assembly as recited in claim 138, one of said multiple briquetting machines being off-line without reduction in briquette production. UTILITIES ASSEMBLY 165. In a processing plant for reducing wet iron ore fines under 1/2", a utilities assembly comprising

conduit means for connecting the processing plant to an industrial water source to provide a source for boiler feed water;

sand and carbon filter means for filtering sand and carbon from boiler feed water; said sand and carbon filter means being located within said conduit means;

deionizer means for deionizing boiler feed water; said deionizer means being located within said conduit means;

deaerator means heating boiler feed water to 10°C with low pressure steam to drive off O2. 166. The utilities assembly as recited in claim 165, said processing plant including a generator steam turbine condenser;

boiler feed water being combined with returning condensate from the generator steam turbine condenser. 167. The utilities assembly as recited in claim 165, boiler feed water being treated with hydrazine. 168. The utilities assembly as recited in claim 165, said deaerator holding at least a 1/2 hour inventory of boiler feed water to allow operation during short term power failures . 169 . In a processing plant for reducing wet iron ore fines under 1/2 " , a utilities assembly comprising

a CCW sump; and

conduit means providing a path for machinery cooling water to be delivered from said CCW sump to said processing plant. 170. The utilities assembly as recited in claim 169, said processing plant including

heat exchangers;

said machinery cooling water providing coolant to said heat exchangers. 171. The utilities assembly as recited in claim 169, said utilities assembly including

return machinery cooling water conduit means for returning machinery cooling water to said CCW sump at a temperature of about 70°C. 172. The utilities assembly as recited in claim 169, said utilities assembly including

a closed heat exchange system;

said machinery cooling water being cooled in said closed heat exchange system to avoid contamination of machinery cooling water by dust. 173. In a processing plant for reducing wet iron ore fines under 1/2", a utilities assembly including

process cooling water source means for cooling and for scrubbing dust from process gas streams. 174. In a processing plant for reducing wet iron ore fines under 1/2", a utilities assembly including two primary and one secondary settling ponds;

return conduit means providing a path for water returning from the processing plant for deposit into said two primary and one secondary settling ponds.

175. The utilities assembly as recited in claim 174, said water returning including

fine particles;

said fine particles settling in said settling ponds. 176. The utilities assembly as recited in claim 175, said fine particle settling being aided by a flocculant. 177. The utilities assembly as recited in claim 174, said water returning being cooled to about 60°C in said settling ponds. 178. The utilities assembly as recited in claim 174, said utilities assembly including

an evaporative type cooling tower;

said water returning from the ponds being pumped to said evaporative type cooling tower. 179. The utilities assembly as recited in claim 178, said water returning being cooled to about 30°C in said evaporative type cooling tower. 180. In a processing plant for reducing wet iron ore fines under 1/2", a utilities assembly including

a steam turbine generator;

boiler means for driving the steam turbine generator, for providing steam for the processing plant, and for providing fluidizing steam. 181. The utilities assembly as recited in claim 180, said boiler means including

a flue;

said boiler means providing inert gas from said flue . 182. In a processing plant for reducing wet iron ore fines under 1/2", a utilities assembly including

a refrigerant type water chiller for providing chilled cooling water. 183. The utilities assembly as recited in claim 182, said chilled cooling water being chilled to about 10°C. 184. The utilities assembly as recited in claim 182, said chilled cooling water being used for drying purge gas and instrument air. 185. The utilities assembly as recited in claim 182, said processing plant including

a reformer with combustion gas;

said combustion gas from said reformer being cooled and dried using said chilled cooling water. 186. The utilities assembly as recited in claim 185, said processing plant including

briquetting and reactor assemblies;

said cooled and dried combustion gas being used as an inert gas for purging and for blanketting in the briquetting and reactor assemblies. 187. The utilities assembly as recited in claim 185, a small amount of inert gas being compressed to about 100 kg/cm2 and stored in tanks to be used for blasting plugged purges. 188. In a processing plant for reducing wet iron ore fines under 1/2", a utilities assembly including two electric motor driven compressors for providing instrument and utility air. 189. The utilities assembly as recited in claim 188, said instrument air being dried using chilled water and dessicant. 190. The utilities assembly as recited in claim 188, said utilities assembly including

an inert gas pressure means;

said inert gas pressure means including

a pressure letdown valve;

said instrument air being backed up by pressurized inert gas via said pressure letdown valve. 191. In a processing plant for reducing wet iron ore fines under 1/2", a utilities assembly including

a condensing steam turbine assembly; and, an electric generator;

said electric generator being driven by said condensing steam turbine assembly and providing power for emergency plant lighting, UPS backup, Fire water pump, inert gas compressor, air compressor, BFW treating pump, BFW feed pump, machinery cooling water pump, process cooling water pump, fans, and, BFW circulation pump. 192. The utilities assembly as recited in claim 191, condensate from said condensing turbine being recycled. 193. In a processing plant for reducing wet iron ore fines under 1/2", a utilities assembly including

a gas turbine generator with steam generation ia exhaust gas;

said gas turbine generator providing power for emergency plant lighting, UPS backup, Fire water pump, inert gas compressor, air compressor, BFW treating pump, BFW feed pump, machinery cooling water pump, process cooling water pump, fans, and, BFW circulation pump. PROCESS CLAIMS: 194. A process for fluidized iron ore reduction of raw iron ore fines under 1/2" in a processing plant including a multi-stage fluid bed reactor assembly, comprising:

a) a process for preparing and feeding raw iron ore fines comprising

drying said raw iron ore fines of free water to a temperature of about 100°C using a natural gas fired kiln;

screening oversize material;

pressurizing said raw iron ore fines and developing a pressurized raw ore charge;

continuously feeding said pressurized raw ore charge at a pre-determined ore feed rate into said reactor assembly, when said reactor assembly is in operation;

b) a process for preheating said fines comprising

developing a pressurized bed of iron ore in a preheat reactor;

developing a temperature of approximately 760°C by injecting and igniting natural gas and air within said bed of iron ore;

fluidizing said bed of iron ore by passing pressurized air, natural gas and combustion gases upward through said bed of iron ore; said pressurized air, natural gas and combustion gases being referred to as flue gas;

passing said pressurized raw ore charge through said fluidized bed;

removing entrained solids from said flue gas and re-inserting into said fluidized bed;

driving off residual and bound water from said raw ore charge; and,

bringing preheated ore charge temperature to reaction conditions and developing a preheated ore charge;

c) a process for reducing said fines including developing a plurality of pressurized beds of iron ore staggered downward from a first bed to a last bed;

fluidizing said plurality of beds by passing a product reducing gas upward through each of said plurality of beds from said last bed to said first bed;

removing oxygen from said fines by passing said preheated ore charge through each of said plurality of beds from said first bed to said last bed gravimetrically;

producing a 90%+ metallized reduced ore powder at a temperature of approximately 780-790°C;

d) a process for preparing fresh reducing gas comprising

producing a hydrogen effluent in a reformer by reacting natural gas with steam;

catalyzing said reacting of natural gas with steam with a nickel catalyst;

increasing hydrogen content in said hydrogen effluent by means of a water-gas shift reaction;

removing most CO2 and H2O from said effluent by passing said gas mixture through a Benfield CO2 removal system;

producing fresh reducing gas with a hydrogen content of approximately 86% on a wet basis ;

e) a proces s for recycling reducing gas comprising

removing cycled reducing gas from said first bed;

recycling said cycled reducing gas by passing said cycled reducing gas through a scrubber system to remove solids and water formed by the reaction of H2 with O2 in the reactors and producing a recycled reducing gas; and developing a product reducing gas for said reactor assembly by mixing fresh reducing gas and recycled reducing gas, compressing said fresh reducing gas and recycled reducing gas, and heating said fresh reducing gas and recycled reducing gas to reaction temperature in a furnace, and, passing said product reducing gas to the reactor assembly;

f) a process for briquetting reduced ore fines comprising

dissipating pressure of said reduced ore powder;

pressing said reduced ore powder between two revolving rolls and molding said reduced ore powder into semi-continuous sheets of briquettes;

breaking said semi-continuous sheets of briquettes into individual briquettes;

separating fines from said briquettes;

cooling and passivating said briquettes with air on a rotary cooler; and,

stacking said briquettes for shipment.

195. A process for fluidized iron ore reduction as in claim 194, said raw iron ore fines including

62 - 64% iron on a wet content basis. 196. A process for fluidized iron ore reduction as in claim 194, removing 3 - 7% free water from said raw iron ore fines in the kiln drier.

197. A process for fluidized iron ore reduction as in claim 194, removing bound water as said pressurized ore charge passes through the preheat reactor. 198. A process for fluidized iron ore reduction as in claim 194, removing entrained fines during recycling of cycled reducing gas with a water scrubber; and recovering said entrained fines in settling ponds. 199. A process for fluidized iron ore reduction as in claim 194 , depositing some carbon on said preheated ore charge in the reactor assembly to increase weight slightly. 200. A process for fluidized iron ore reduction as in claim 194, recovering 92 - 94% of said reduced ore powder in briquette form. 201. A process for fluidized iron ore reduction as in claim 194, molding said reduced ore powder into pillow-shaped briquettes roughly double the size of a charcoal briquette. 202. A process for fluidized iron ore reduction as in claim 194, said briquettes having

a mass of approximately .4 - .8 kilograms, depending on the size of the briquetter roll pocket. 203. A process for fluidized iron ore reduction as in claim 194, developing a briquette having a porosity, defined as the fraction of the bulk volume of the material occupied by voids, ranging from 25 - 30%.

204. A process for fluidized iron ore reduction as in claim 194, developing a briquette with a hard inert shell retarding back-oxidation. 205. A process for fluidized iron ore reduction as in claim 194, said hard inert shell being produced by applying high compression during briquette molding and subsequent air passivation. 206. A process for fluidized iron ore reduction as in claim 194, said briquettes being manageable as any bulk material and being largely unaffected by the elements including heavy rains. 207. A process for fluidized iron ore reduction as in claim 194, said briquettes including

a 90+% metallization and a total iron content of 90+% with a carbon level from .5 - 2.5% as desired. 208. A process for fluidized iron ore reduction as in claim 194, the loss of metallization being under 1%. 209. A process for fluidized iron ore reduction as in claim 194, said pre-determined ore feed rate approximating 90 tons/hour. 210. A process for fluidized iron ore reduction as in claim 194, producing briquettes at a rate approximating 60 tons/hour. 211. A process for fluidized iron ore reduction as in claim 194, producing hydrogen gas at aa rate approximating 34,000 cubic meters/hour with an 85.8% volumetric purity. 212. A process for fluidized iron ore reduction as in claim 194, said product reducing gas including

60% hydrogen and 22% CH4 by volume. 213. A process for fluidized iron ore reduction as in claim 194, the reactor temperatures approximating 700 - 800°C. 214. A process for fluidized iron ore reduction as in claim 194, said pressurized ore charge having up to 9.5-mm diameter particle size. 215. A process for fluidized iron ore reduction as in claim 194, said process for preparing and feeding ore including

developing a supply store of raw ore charge as needed in a storage bin to feed said raw ore charge to said reactor assembly continuously, when said reactor assembly is in operation. 216. A process for fluidized iron ore reduction as in claim 194, venting a small amount of said recycled reducing gas to a fuel gas system for pressure control. 217. A process for fluidized iron ore reduction as in claim 194, said process for fluidized iron ore reduction including

a process whereby utilities are provided. 218. A process for fluidized iron ore reduction as in claim 194, maintaining isolated conditions of said ore charge from the end of said preheat process until the end of said briquetting process. Process for Ore Preparation & Feed 219. In a process for fluidized iron ore reduction of raw iron ore fines under 1/2" in a processing plant including a multi-stage fluid bed reactor assembly, a process for ore preparation and feed comprising:

feeding a mainstream of iron ore fines into a drier;

drying said raw iron ore fines of free water to a temperature of about 100°C and developing a mainstream of dried fines;

screening oversize material away from said mainstream of dried fines;

pressurizing said mainstream of dried fines and developing a pressurized raw ore charge;

continuously feeding said pressurized raw ore charge at a pre-determined ore feed rate into said reactor assembly, when said reactor assembly is in operation. 220. A process for ore preparation and feed as in claim 219, said process for ore preparation and feed including

removing entrained fines from said drier by forcing said entrained fines through dry cyclones with drier combustion gases and a blower;

diverting de-entrained fines to said mainstream of dried fines;

scrubbing combustion gases exiting the cyclones with a venturi type scrubber and exhausting. 221. A process for ore preparation and feed as in claim 219, said process for ore preparation and feed including

developing a 10 -12 hour inventory of dried fines . 222. A process for ore preparation and feed as in claim 219, said process for ore preparation and feed including

drying said raw iron ore fines to a free water content of under 0.2%. 223. In a process for fluidized iron ore reduction of raw iron ore fines under 1/2" in a processing plant including a multi-stage fluid bed reactor assembly, a process for ore preparation and feed comprising:

feeding dried fines from feed bins to the top of said reactor structure utilizing a variable speed feed conveyor;

discharging said dried fines from discharge chutes into a lockhopper surge line;

varying the feed conveyor rate to maintain levels of dried fines in the surge line within pre-specified levels;

feeding dried fines from a surge bin into a weigh bin utilizing a charge conveyor to a pre-specified ore charge weight;

shutting down the charge conveyor once the pre-specified charge weight is achieved;

loading the ore charge into an upper lockhopper; sealing the upper lockhopper after the ore charge is loaded and pressurizing to a pre-specified preheat reactor pressure to which a lower lockhopper has previously been pressurized;

unloading the pressurized charge into the lower lockhopper; de-pressurizing the upper lockhopper to await loading of the next ore charge;

metering the ore from the lower lockhopper into the reactor assembly. 224. A process for ore preparation and feed as in claim 223, said process for ore preparation and feed including

loading a second pair of upper and lower lockhoppers in parallel relation with said upper and lower lockhoppers to assure maintenance of a pre-determined ore feed rate in the case of mechanical failure of one pair of lockhoppers.

Process for heating ore to Reaction Temperature and Removing Hydrated Water 225. In a process for fluidized iron ore reduction of raw iron ore fines under 1/2" in a processing plant including a multi-stage fluid bed reactor assembly including a preheat reactor, a process for pre-heating ore to reaction temperature and for removing hydrated water from iron ore fines comprising:

developing a pressurized bed of iron ore in a preheat reactor;

passing said pressurized raw ore charge through said fluidized bed;

driving off residual and bound water from said raw ore charge; and,

bringing preheated ore charge temperature to reaction conditions and developing a preheated ore charge. 226. A process for pre-heating ore to reaction temperature and for removing hydrated water from iron ore fines as in claim 225, said process for pre-heating ore to reaction temperature and for removing hydrated water from iron ore fines including:

facilitating the combustion of natural gas by enrichening said flue gas with pre-heated, compressed air to a level of 2% O2. 227. A process for pre-heating ore to reaction temperature and for removing hydrated water from iron ore fines as in claim 225, said process for pre-heating ore to reaction temperature and for removing hydrated water from iron ore fines including:

injecting purge gas comprising steam into the burners to prevent plugging when natural gas flow is low. 228. A process for pre-heating ore to reaction temperature and for removing hydrated water from iron ore fines as in claim 225, said process for pre-heating ore to reaction temperature and for removing hydrated water from iron ore fines including:

cooling combustion gases with a water quench or steam heat exchanger;

scrubbing the combustion gases in a venturi-type scrubber; venting the combustion gases through a series of pressure letdown valves and out a stack. 229. A process for pre-heating ore to reaction temperature and for removing hydrated water from iron ore fines as in claim 225, said process for pre-heating ore to reaction temperature and for removing hydrated water from iron ore fines including:

maintaining constant flow of solids through said preheat reactor with the use of gravity flow and through the operation of cycling slide valves within ore inlet pipes. 230. A process for pre-heating ore to reaction temperature and for removing hydrated water from iron ore fines as in claim 225, said process for pre-heating ore to reaction temperature and for removing hydrated water from iron ore fines including:

injecting a flow of inert gas through ore outlet pipes to prevent air from being carried into the balance of the reducing reactor assembly. Process for Reducing Iron Ore Fines in a Fluid Bed 231. In a process for fluidized iron ore reduction of raw iron ore fines under 1/2" in a processing plant including a multi-stage fluid bed reactor assembly including a preheat reactor, a process for reducing iron ore fines in a fluid bed comprising:

developing a plurality of pressurized beds of iron ore staggered downward from a first bed to a last bed;

fluidizing said plurality of pressurized beds by passing a product reducing gas upward through each of said plurality of pressurized beds from said last bed to said first bed; removing oxygen from said fines by passing said preheated ore charge through each of said plurality of beds from said first bed to said last bed gravimetrically;

producing a 90%+ metallized reduced ore powder at a temperature of approximately 780-790°C. 232. A process for reducing iron ore fines in a fluid bed as in claim 231, said process for reducing iron ore fines in a fluid bed including:

developing an evenly distributed upflowing stream of reducing gas through each of said plurality of beds with the use of a grid placed below each of said plurality of beds. 233. A process for reducing iron ore fines in a fluid bed as in claim 231, said process for reducing iron ore fines in a fluid bed including:

maintaining a pressure seal at the outlet to the reactor assembly by stacking ore in a column. 234. A process for reducing iron ore fines in a fluid bed as in claim 231, said process for reducing iron ore fines in a fluid bed including:

pre-heating reducing gas to 850-875°C prior to entering the last bed in order to speed and sustain the endothermic reduction reaction, and to make briquetting easier. 235. A process for reducing iron ore fines in a fluid bed as in claim 231, said process for reducing iron ore fines in a fluid bed including:

injecting a fine oxide powder into the last bed in order to prevent defluidization.

236. A process for reducing iron ore fines in a fluid bed as in claim 231, said process for reducing iron ore fines in a fluid bed including:

injecting a small amount of natural gas to maintain carbon control within a pre-specified range, and optimally, sulfur to form a small amount of H2S if required to protect reducing gas heater tubes from metal dusting attack. 237. A process for reducing iron ore fines in a fluid bed as in claim 231, said process for reducing iron ore fines in a fluid bed including:

utilizing dried process gas purges for instrumentation pressure taps and for maintaining clean blasting connections where the dried process gas comes from the spent reducing gas recycle system. 238. A process for reducing iron ore fines in a fluid bed as in claim 231, said process for reducing iron ore fines in a fluid bed including:

transferrring the reduced iron product from the reactor assembly to a briquetter assembly through a pneumatic transfer line. 239. A process for reducing iron ore fines in a fluid bed as in claim 231, said process for reducing iron ore fines in a fluid bed including:

controlling solids withdrawal rate from the last bed by a cycling slide valve at the reactor assembly outlet resulting in a semi-pneumatic type of transport. 240. A process for reducing iron ore fines in a fluid bed as in claim 231, said process for reducing iron ore fines in a fluid bed including: quenching reduced product in a quench drum. Process for Preparing Reducing Gas 241. In a process for fluidized iron ore reduction of raw iron ore fines under 1/2" in a processing plant including a multi-stage fluid bed reactor assembly, a process for preparing fresh reducing gas comprising:

producing a hydrogen effluent in a reformer by reacting natural gas with steam;

catalyzing said reacting of natural gas with steam with a nickel catalyst;

producing fresh reducing gas with a hydrogen content of approximately 86% on a wet basis for said reactor assembly. 242. In a process for fluidized iron ore reduction of raw iron ore fines under 1/2" in a processing plant including a multi-stage fluid bed reactor assembly, a process for recycling reducing gas comprising:

removing cycled reducing gas from said first bed;

recycling said cycled reducing gas by passing said cycled reducing gas through a scrubber system to remove solids and water formed by the reaction of H2 with O2 in the reactors and producing a recycled reducing gas for said reactor assembly. 243. In a process for fluidized iron ore reduction of raw iron ore fines under 1/2" in a processing plant including a multi-stage fluid bed reactor assembly, a process for preparing reducing gas comprising:

passing natural gas from a natural gas source through a condensate knockout drum;

compressing natural gas to approximately 25 kg/cm2 if required;

adding a small recycle stream of hydrogen to the natural gas for hydrogenation of sulfur compounds;

preheating to 370°C in a heat exchanger, where heat is transferred by cooling the reformed gas;

catalyzing in a cobalt-molybdenum catalyst filled vessel promoting reaction of non-H2S components with H2 to form H2S, which can then be removed by ZnO;

passing through two ZnO filled vessels connected in series to remove H2S contained in the natural gas;

periodically re-filling vessels with ZnO;

mixing with superheated steam at 500°C in a ratio of 3.3 moles of steam per mole of natural gas;

heating to 600°C in the heat recuperation section of the reformer;

heating to 825°C while passing through nickel containing reformer catalyst to produce the reforming reaction;

providing combustion air for the burners by a forced draft;

preheating combustion air to about 300°C with the reformer combustion gases to reduce reformer fuel requirement;

passing combustion air through suction filters prior to entering furnace to prevent the entrance of dust. 244. A process for preparing reducing gas as in claim 243, said process for preparing reducing gas including: developing a product reducing gas for said reactor assembly by mixing fresh reducing gas and recycled reducing gas, compressing said fresh reducing gas and recycled reducing gas, and heating said fresh reducing gas and recycled reducing gas to reaction temperature in a furnace, and, passing said product reducing gas to the reactor assembly. 245. In a process for fluidized iron ore reduction of raw iron ore fines under 1/2" in a processing plant including a multi-stage fluid bed reactor assembly, a process for recycling reducing gas comprising:

cooling the spent reducing gas after it exits the reactors by generating steam in a wast heat boiler, or alternatively by quenching in a water cooled tower;

scrubbing in a venturi scrubber;

removing a small amount of gas and burning in the reducing gas preheater to prevent inert gas build-up;

compressing for return to reactors;

removing some of the recycle gas, drying, and compressing to about 20 kg/cm2 for use in the reactor purges;

compressing the balance of the gas in a centrifugal compressor and mixing with the product gas from the CO2 removal system in a ratio of 3.5 parts recycle gas to 1 part product gas (also referred to as makeup gas);

adding a small amount of H2S is added to the gas to prevent metal dusting of the reducing gas preheater, where sulfur is not being added directly to the reactors;

passing the combined gas stream (called total reducing gas) through a reducing gas preheater and heating to 850 to 875 °C;

separately heating the total reducing gas and the combustion air streams in the heat recuperation system; heating the reducing gas to about 500 °C in the recuperator and to 875 °C in the radiant box;

preheating the combustion air to temperatures dependant upon the furnace design;

passing the heated gas through a refractory lined pipe to the bottom reducing reactor;

cooling the reducing gas preheater combustion gases to about 135 °C in the heat recuperator. Process of Reformer Heat Recuperation 246. In a process for fluidized iron ore reduction of raw iron ore fines under 1/2" in a processing plant including a multi-stage fluid bed reactor assembly and a reformer assembly, a process for reformer heat recuperation comprising:

reducing the temperature of the combustion gases from 970°C to about 135°C by preheating feed streams for the reformer, preheat reactor air, and combustion air for the reformer burners;

forcing exit of the gases into a stack by means of an induced draft fan while, simultaneously, exchanging heat with the following process streams: 1. Preheat reactor air (2d exchanger); 2. Steam and natural gas feed; 3. Steam (superheat); 4. Preheat reactor air (1st exchanger); 5. Boiler feed water (Steam generation); 6. Reformer combustion air;

utilizing the cooled gas as an inert gas in the areas where inert blankets must be maintained. Process for Reformed Gas Cooling and Shift 247. In a process for fluidized iron ore reduction of raw iron ore fines under 1/2" in a processing plant including a multi-stage fluid bed reactor assembly and a reformer assembly, a process for reformed gas cooling and shift comprising:

cooling the reformed gas mixture leaving the reformer tubes from 825°C to 370°C while simultaneously generating 25 kg/cm2 steam by means of an exchanger;

utilizing the steam as part of the feed to the reformer [along with steam produced in the recuperator];

passing the cooled reformed gas through a high temperature shift (HTS) reactor filled with an iron-chrome catalyst for reacting the CO remaining in the reformed gas mixture with H2O to produce more H2;

cooling the product gas to about 360°C in a natural gas preheat exchanger using incoming natural gas;

passing the reformed gases through a second exchanger to cool to about 180°C while heating boiler feed water for the reformer. Process for Reformed Gas CO2 Removal 248. In a process for fluidized iron ore reduction of raw iron ore fines under 1/2" in a processing plant including a multi-stage fluid bed reactor assembly and a reformer assembly, a process for reformed gas CO2 removal comprising:

reboiling the reformed gas by means of an exchanger;

passing through an absorption tower where the reformed gas is contacted by a downflowing lean potassium carbonate solution which absorbs most of the CO2 from the reformed gas;

reducing water content of the reformed gas by condensation;

introducing said lean carbonate solution to the absorption tower at two points permiting CO2 removal to under 0.5% in the purified reformed gas;

regenerating the rich carbonate solution containing CO2 and H2O removed from the reformed gas in a regenerator tower by flashing the solution to essentially atmospheric pressure at the top of the tower;

stripping the carbonate solution of CO2 and H2O by means of a reboiler at the bottom of the column;

pumping the regenerated, or lean solution out of the bottom of the regenerator and back to the absorber;

cooling part of the regenerated solution with an air cooled exchanger;

venting the CO2 and H2O liberated from the rich solution from the top of the regenerator tower;

producing reformed gas exiting the CO2 removal system with a content of about 3.5% H2O and 0.5% CO2. Process for Briguetting 249. In a process for fluidized iron ore reduction of raw iron ore fines under 1/2" in a processing plant including a multi-stage fluid bed reactor assembly and a reformer assembly, a process for briquetting reduced iron ore fines, comprising:

transporting the hot, reduced ore fines from the bottom reducing reactor to an atmospheric storage drum which feeds the three briquetting machines;

metering the reduced fines from the storage drum into the briquetting machines be a cycling slide valve;

pouring The fines into a small feed drum on top of the briquetting machine;

forcing the fines between two counter-rotating rolls by a helical feed screw compressing the fines into briquettes ; separating the strings of briquettes from the mold into individual briquettes with a rotating trommel. 250. A process for briquetting reduced iron ore fines as in claim 249, said process for briquetting reduced iron ore fines including: separating the fines and chips from the briquettes with a screen. 251. A process for briquetting reduced iron ore fines as in claim 249, said process for briquetting reduced iron ore fines including: quenching the product briquettes in a water filled tank to 100°C;

discharging the briquettes onto a product conveyor where they are dried by the heat remaining in the briquettes. 252. A process for briquetting reduced iron ore fines as in claim 249, said process for briquetting reduced iron ore fines including: passing the briquettes, fines and chips over a 1/2" and 1/4" screen;

quenching the chips between 1/2" and 1/4" in diameter in a water quench tank and discharging in a pile for sale as a byproduct. 253. A process for briquetting reduced iron ore fines as in claim 252, said process for briquetting reduced iron ore fines including:

recycling the fine fraction under 1/4" diameter back to the briquetters via a bucket conveyor; alternatively, quenching fines in a quench tank when they are not being recycled. 254. A process for briquetting reduced iron ore fines as in claim 249, said process for briquetting reduced iron ore fines including:

blanketting the entire briquetter assembly with inert gas under a slightly positive pressure, where The inert gas is of low CO2 content in order to reduce the oxidation potential of the gas. 255. A process for briquetting reduced iron ore fines at temperatures above 700°C, which are easily fluidized and which oxidize readily, comprising

a) reduced iron ore fines are pneumatically transferred into a briquetter feed drum (or storage hopper) located above the briquetting building for substantially gravimetric feed and for reduction in mechanical transfer equipment, said feed drum allows exhaust of the pneumatic conveying gas with a minimum entrainment, the bottom portion has a sufficient capacity to ensure uninterrupted supply to any of multiple briquetting machines, and the feed drum is insulated to minimize heat losses;

b) the fines are discharged on feed lines for the respective briquetting machines while unwanted material is separated & discharged into a quench drum;

each feed line is insulated and include material flow control valves which admit solids through the feed line into the briquetter feed hoppers such that solids pass down the feed lines at a controlled rate sufficient to supply the briquetter without slugging or upsetting the operation of the feed hopper,

an improved feed screw in the feed hopper provides the controlled flow of the reduced iron ore fines to multiple briquetting rolls , water cooling is provided for the feed screw;

c) the reduced powder is pressed between revolving roll type briquetting presses shaping the material into a semi-continuous sheet of pillow-shaped briquettes , each roll assembly has eight segments which are secured with keys and shrink-on rings , mounted in an H-frame to accommodate side removal, roll pre-loading forces are developed by means of hydraulic cylinders , the hydraulic system is also utilized with auxiliary hydraulic cylinders to permit rapid removal of the roll assemblies , load cells are incorporated into the briquetter assembly to provide instrumentation for recording the separating forces at the operator ' s control console , water cooling is provided for the arbors of the roll assemblies and the shrink-on rings , the working surface of the segments is lubricated by proprietary compounds which are uniformly spread at a controlled rate across the width of the segments where the lubrication system is independent for each briquetter and the lubricant is automatically fed from a common supply source;

d) a semi-countinuous string of briquettes are discharged from the rolls and are gravimetrically fed to multiple trommels where the briquettes, are broken into individual units by tumbling and fines & chips are separated from the briquettes,

the trommels are similar to a rotary kiln with an adjustable slope angle and have a variable speed drive to optimize the retention time of the material, an internal screen separates fines and chips from the whole briquettes, two discharge chutes provide an exit from the trommels where one chute is for briquettes and the other is for fines & chips; e) the briquettes are evenly distributed onto a rotary cooler for cooling and passivating by air by means of multiple, airtight, inerted, vibrating conveyors which includes passing through a screening station for removal of fines & chips,

the cooler is a rotary grate type mounted on a central pedestal, high velocity air is discharge at about 300 m/minute from a plenum beneath the rotary grate of the cooler and through the briquettes, the briquettes are deposited onto the cooler at temperatures of 650+°C for passivation with a high degree of chemical stability; f) from the cooler, briquettes are removed by a magnetic drum unloader which discharges the briquettes onto a conveyor belt system which in turn stacks the briquettes in stock pile locations; and,

g) a one man central control room operates the entire briquetting plant. Process for Providing Utilities 256. A process for providing utilities comprising:

receiving boiler feed water from the industrial water main;

treating with sand and carbon filters ; passing through deionizers ;

mixing the feed water with returning condensate from the generator steam turbine condenser;

pumping to a deaerator and heating to 110 °C with low pressure steam to drive off 02 ;

adding hydrazine if required;

maintaining a 1 / 2 hour inventory in the deaerator to allow operation during short term power failures .

257. A process for providing utilities including a process for providing machinery cooling water to cool machinery and to provide coolant in heat exchangers, said process for providing machinery cooling water including:

pumping water to the users from a CCW sump;

cooling said water, on return, in a close heat exchange system to avoid contamination of the water by dust;

returning at a temperature of about 70 °C. 258. A process for providing utilities including a process for providing process cooling water required for cooling process gas streams and for scrubbing dust from process gas streams and from gases pulled through the dust collectors, said process for providing process cooling water including:

returning the water from the various users to two primary and one secondary settling ponds where fine particles settle out, aided by a flocculant where two ponds are provided so that they can be cleaned on the run;

cooling the water to about 60°C in the ponds; pumping cooled water from the ponds to an evaporative type cooling tower where the water is cooled to about 30 °C;

pumping water from the sump to the users;

chilling a small amount of cooling water to about 10°C utilizing a refrigerant type water chiller providing chilled water for drying purge gas and instrument air;

cooling and drying combustion gas from the reformer using the chilled cooling water. 259. A process for providing utilities including a process for providing instrument and utility air including: utilizing one of two electric motor driven compressors;

drying air using chilled water and dessicant; backing up air with 100 kg/cm2 inert gas storage tanks via a pressure letdown valve. 260. A process for providing utilities including a process for providing a backup for protection against power failures including:

utilizing a condensing steam turbine driven electric generator to provide sufficient power for: 1. Emergency plant lighting, 2. UPS backup, 3. Fire water pump, 4. One inert gas compressor, 5. One air compressor, 6. One BFW treating pump, 7. One BFW feed pump, 8. One machinery cooling water pump, 9. One process cooling water pump, 10. All four fans on the furnaces, 11. One BFW circulation pump (reformer), where alternatively, a gas turbine generator with steam generation by the exhaust gas can be used in place of the boiler with steam turbine driven electric generator;

maintaining redundancy capability for each of the above-named pumps and compressors by specifying 100% capacity capability of each unit, and hooking one of each unit with electric motor drive to the generator;

maintaining two electric motor drives on each fan where The fans are single units;

maintaining the generator in continuous service. Process for Maintenance 261. A process for maintaining a briquetting facility including:

rotating three crews in shifts;

developing two shifts per day; providing each crew with a maintenance foreman, mechanic and two assistants;

drawing welders from plant maintenance crews as needed.

262. A process for maintaining a briquetting facility including:

daily lubrication of valves, briquetters, trommels, and conveyors, adjustment of slide valve operators inspection of cheekplate and adjustment if necessary. 263 . A process for maintaining a briquetting facility including:

routine changeout of rolls ( if necessary) , repair of trommel , removal / cleaning of feed screw , removal/cleaning of slide valve, changeout of cheekplates , maintenance of roll lubrication system. 264. A process for maintaining a briquetting facility including :

semi-annual repair of refractory in surge drum, removal and/ or repair of ball valves in feed lines , cleanout of dust removal system, changeout of damaged trommel internals, changeout of damaged conveyor belts , overhaul of vibrating conveyors .