CA2845422A1 - Integrating coke oven blast furnace operation for direct steelmaking and elimination of slag production - Google Patents

Abstract

A zigzag route of making a mistake and then correcting it is practiced in the present in the major route of integrated route of steel production. Impurities (sulfur, metallic residue) containing Coke is produced and when this is charged into blast furnace an impure inferior product is produced. Gases and charge are processed counter current in the blast furnace creating large blown out material requiring recovering and agglomeration it ,sintering plant. Next two processes namely BOF and Ladle processing are to rectify the previous mistake of iron making and steelmaking.
Steel is cast in large size ingots and blooms having internal and external defects so surface scarfing and reheating and size reduction, scale disposing is done until the product becomes appropriate for next operation of rolling. Lot of cutting and re-joining is done producing defective portions. The rolling operation is done in air and then storing in air. The rusted surface has to be prepared by annealing and pickling for next operation of coating. Pickling creates deep defects and non uniformity in steel structure.
Cold rolling is liable to produce micro-cracks in the internal structure of metal.
Against this back ground in the presence process steel is produced using high purity gases and iron ore: steel is produced directly .Unwanted ingredients in iron ore are slaged off. Alloying elements when desired are added some as ores and some after steel is formed in blast furnace.
Energy is recovered from liquid steel and it is directly made into appropriate temperature and dimension to perform next operation. Near net size products are produced which are given on line heat treatment in controlled atmosphere. The steel is brought in to air after required surface protection has been performed. On line heat-treatment eliminates the cold rolling.
Intermediate cutting is seldom performed where there is need of certain relaxation between two operation closed atmospheres accumulators are provided,

Description

Integrating Coke oven Blast furnace operation for Direct Steelmaking and elimination of slag production.
This above named invention is of far reaching consequences for integrated Blast furnace Bof steel making technology.
It will create a more precise, straight forward, continuous process from start to finish liable to automation and control, without generation solid or gaseous waste.
Most of the present heavy set up will be utilized for this new technology with some external modifications. Units which become redundant will be by-passed.
Present unit operations of Sintering plant, Steelmaking, De-oxidation, Ingots, Blooms, Slab casting, reheating furnaces, scale disposal and much of cutting and welding will give way to the point operations with introduction new on line operations which will make the product better in mechanical properties and resistant to external damages.
I will first describe the basic unit namely coke ovens which is base of all this change.
It is the production of high purity high energy gases CO3H2 in oven operation which make all this possible. Further separating these gases into CO and H2 and joining with these 02 and N2 from air will make the foundation of new chemical world.
While fulfilling the needs for new requirements from these ovens; these will also provide some petrochemicals which use to be provided by coking process which is now stopped.
Coke oven complex produces coke, byproducts, and coal gases from coal .The coke oven byproduct plant is designed for production solid fuel for process needs to cover the steel mill's own requirement and some excess coke for foundry purposes.
The requirements for the steel mill in solid fuel for process needs are made up of the blast furnace demand for the metallurgical coke. There is an additional demand for coke breeze for sintering plant refractory making (fire clay), coke oven and by product plant is also part of coke production plant.
For all these requirements the coke and breeze is 960 thousand tons per annum, for a steel mill of one million tons of steel per annum.
The coke oven and by product plant has been designed as follows:
-coal handling plant -coke oven plant -by-product plant-Auxiliary facilities: water supply, sewerage, steam supply, electric power supply, repair posts, laboratory, recoveries plant facilities, communication and signaling facilities.
The cove oven plant consists of two coke oven batteries, 49 ovens in each, their carbonizing chambers having 30.4 cu.m effective capacity; the coal tower 3200 tons capacity and two 80 meter stacks having 3.6 m upper inner diameter.
On the coke side, running along the ovens, there are quenching car tracks, the coke wharf for discharging the quenching coke from the quenching car, and the quenching station with facilities for settling and delivery of water for coke quenching.
On the pushing side of the coke oven battery are coke pusher tracks and stacks with collecting and common flues.

Coke ovens of under jet and control of coke oven gas and air, with twin heating flues and recirculation of waste heat gases. Coke ovens to be heated with coke oven gas.
Dimension of carbonization chamber.
Length =15000rrun Height =5200 mm Width =410 mm Effective volume of carbonization chamber cu.m =30.3 Number of charging holes pcs =3 Number of gas off-take holes, pcs =2 Single charge 3-5 mm =22 ton Oven cycle, hours =15 By ¨ Products Recovery Plant The by product recovery plant consists of the following sections and facilities:
Tar condensation and gas cooling station, Machine room.
Ammonium sulfate section Section of final gas cooling and purification of gas from naphthalene.
Sulfuric acid storage Tar and solar oil storage Gas Bleeder.
The following are usually produced at the by-product recovery plant:
Tar Ammonium sulphate Solar oil used for generation.
Gas is cooled through tubular heat exchangers. and then through electrostatic precipitator.
Changing coke ovens to perform new technology.
This new technology is to produce high purity CO,H2 gases , (with small % of N2 )from the ovens from a charge of sulfur containing coal and house hold garbage (biomass.
annual crop residues) This changed technology and small changes in setup is described below and illustrated with figure 1.
Ovens are changed coal or mixed hydrocarbons (coals and garbage) gasifier. The operation of coal charging machine is stopped and small charge hoppers are made over every ovens one for coal and two for mix charge. From these hoppers the materials are charged by screw feeders continuously into the oven. The gas off takes is used for gases inlet one for oxygen and one for steam or CO2. The material is gasified in side oven and bottom of the oven is made slanting so that ash is its self gathered at the exit pipe. At the exit pipe product gases which are reducing gases flow to an exit pipe upward going to previous gases collection mains and pipes, The ash is made to flow trough a controlled screw to &collecting hopper. The ash from this collecting hopper is taken away by previously coke carrying trolley. The coke gate is closed with refractory, small pipe for out going of ashes and gas is made Each oven is heated at the outside by burners using small percentage of purified product gases produced by the oven, A simplified chemical process taking place inside the oven is described as following.
Assume coal as Carbon.

And biomass as Carbon and 1120.
2C +02 =2C0 AH = - 52,000 K.cal.
C +H20 = CO +H2 AH = + 42,000 K.cal To make heat balance some more biomass material and steam is added.
To carry the exit gases and ash at a temperature of about 1100 C heats through the oven walls is used; this heat is supplied by the combustion chambers operating at about 1200C.
The process is not restricted by kinetics of the process but by material transport.
Previously coal was used at an average of 1,5 ton per hour. Now the combine mass is processed at about 2 tons per hour. About 10 % of the product gases are recycled for energy need of the process.
The operation of the coke pusher and coke receiving is stopped.
The process ash from coal and biomass is taken by the coke trolley to the previous quenching stating which is used now for ash process. This ash is cooled to approx, 400 C
and its iron contents and separated by a magnet separator. The rest of the ash is dissolved in caustic soda. The products are used for the preparation of zeolites. The insoluble calcium maximum salt and other are used for their separation and recovery.
Nothing is thrown away.
The product gases from the ovens are collected and hot gases are taken to previously by-product area. Hear first some heat energy from these is used for electricity production .These gases at about 500 C taken to impurities removal by caustic soda.
Caustic soda is removed and recycled. The calcium sulfate is formed which is dried and marketed. This is explained on figure 3.
Theses gases can be separated into high purity CO, 112, N2.
byphysical adsorption and chemical purification. Nitrogen by pressure swing adsorption, CO and H2 (See figure 5 ) by zeolite adsorption process and nitrogen pressure swing adsorption.
These gases can be further changed to:
CO,H2 CO2 +112 (shift reaction) Carbon di-oxide is liquidified and transported.
Cryogenic separation of CO and H2 Production of C from CO
Production of porous graphite from C
Using CO and H2 to produce CH3OH. Use CO and CH3OH to produce Acetic acid. This acid will be a valuable component for new processes development.
Gases CO,H2 have about 30% more calorific value than natural gas.
All our new processes will produce electricity rather than consuming electricity.
No process water or heating electricity is used in the process.
In the following I describe how CaO, and MgO are used to establish basic foundations.
CaO, MgO ,A1203 ,Na2O are in cyclic role. .
Heat balance 15Ca0 +10A1 = 5A1203 + 15Ca +AH = 295 .000 Kcal 18Mg 0 +12 Al = 6A1203 +18 Mg +AH = 174,000 //
3[ 3Si02+ 4A1 =2A1203 + 3Si ] -All =3x 149,000 //

Thus for 100 kg moles of Ca0+Mg0 approx.35 mole silica is used to balance the energy requirement. This energy also includes energy require to volatile the Ca, Mg Na, and heat the circulating 112.
Ca, Mg, which are volatilized are made to under go reaction to reduceCO, CO2 and H20 to produce C2H2and C3H4 gases which being highly unsaturated can lead to self condensation, mutual condensation and saturation reaction with H2 thus starting the whole new field of petro-chemicals, gasoline, diesel, waxes and polymers in more systematic and controlled manner than crude oil cracking technology.
Energy recovery from off gases and conversion of CO2 and H20 to hydrocarbon gases is shown in figure 6 page 1 and 2.
Calculations for Ca and Mg are parallel. Basic data for Ca ,CaO, Mg and MgO is given in the following -AH fK.cal/kg.mol m.point C b.point C Cp K.cal/kg.mol.0 Ca 839 1484 26 CaO 157.5 2615 12 Mg 649 1000 7.8 MgO 143. 2825 3200 11.7 Mg2C3 19 10.
Using Ca and recycling of CaO

2 CO2+ Ca = CaC2 +4 CaO - EH = 440 K.cal This is large amount of heat and partially this heat to be carried away for electricity generation.
Circulating nitrogen will take out this heat to gas turbine.
Nitrogen is 50 kg mole per minute.
The product charge (CaC2 +4 CaO) is at about 1000 C is taken to the next reactor.
CaC2 is reacted with H20 CaC2+ H20 = C2H2+Ca0 -AH =-25 K.cal this heat is also taken to gas turbine Heat with CaO to recycle pipe =5 CaO @ 1000 C is going to reduction reactor C2H2 goes out and is reacted with H2 C2H2 + H2 =C2H4 AH=- 72 K.cal Cp-10 K.cal/kg.mol C
iH f ethylene= -17.K.cal/kg.mole Temperature of ethylene =1000 C
Heat from ethylene reactor is taken to gas turbine Heat released by Ca =700 * 26 * 5=91000 K.cal Heat from hydrogen cooling 10 *7* 800 =56,000 147,000 Kcal From nitrogen 50*8 * 800 =320,000 Electricity generated from all exit streams is 156 Kwh in one minute A scrap melting plant of 60 tons per hour will produce 9.MWhr.
Using Mg and recycling of MgO

3 CO2+ 8Mg = Mg2C3 +6 MgO - AH= 567 K.cal This is large amount of heat and partially this heat to be carried away for electricity generation.
Circulating nitrogen will take out this heat to gas turbine.

, Nitrogen is 60 kg mole per minute.
The product charge (Mg2C3 +6 MgO) is at about 1000 C is taken to the next reactor.
Mg2C3 is reacted with H20 Mg2C3 + 2H20 = C3114+2Mg0 -AH =-189 K.cal (approx) this heat is also taken to gas turbine Heat with MgO to recycle pipe =8 CaO @ 1000 C is going to reduction reactor C3H4 goes out and is reacted with H2 C3114 +112 =C3H6 AH=- 72 K.cal Cp-10 K.cal/kg.mol C
Ail4h6= -19 K.cal/mol Heat of reaction is taken to turbine Cp Mg0=12 K.cal /kg.mol Mg m.point = 653 b.point =1000 C
Heat released by Mg =27700 K.cal Heat from hydrogen cooling =20,000 47,000 Kcal From nitrogen 60*8 * 800 =384,000 Electricity generated from all exit streams is 143 Kwh in one minute Obtaining of Al from A1203 A special furnace which will work at 2200 C is shown in the attached figure 7.

The CO, CO2, Hz, H20 ,N2 gases in the flue gases can be recovered as hydrocarbon gases (C2H4 and C3H6 ) adding benefit to process.
Flue gases from the exhaust chimney of the coke oven battery are assumed to the following composition. CO,CO2,112,H20,N2. These gases are 10% of the total gases product of charge gasified from the coke-Ovens.
We assume that each oven gasifies the charge mix (50% coal +50% household garbage) 25% of these gases are mixed with flue gases.
Charge mix is C=72,H=12, N=4,0 =2,S=3 Ash 7 kg per 100 kg of charge.
Kg mole per ton of the gasified charge is C=60 kg.mole, H2=60 kg mole, N2=15 Kg.mole 02=6 kg.mole S=1 kg.mole.
Chemical analysis coke ash, per cent Silica Alumina CaO MgO Fe203 Mn 0 SO3 P2O5 TiO2 Alkalies Total 63.1 19.63 2.44 1.22 8.0 0.3 0.3 1.08 0.14 1.9 100 % of the this per hour is CO =60x2=12 kg.mole H2= 60x.2 =12 //
N2= 15x2 =3 //
These gases when burnt with stoichiometric amount of air The product amount is.
CO2= 12 Kg.mole H2 = 12 Kg.mole N2 =3 +48=51 Kg.mole , Heat generated =1392,000 K.cal Heat gone out with flue.
Flue exit temperature =350C.x 84x 8.5 (Cp)=249900 K.cal.
Heat transferred to gasification mass =11421,00 K. cal.
Flue gases when mixes with 25 of the gases produced CO2= 12 Kg.mole, CO= 30 Kg.mole H2 0= 12 Kg.mole,H2=30 I/
N2 =12 +48=51 Kg.mole +0.75=51.75 Total gases CO,CO2,H2,H20,N2. =135.75 Kg.mole These gases are divided 40% to be treated with Ca and 60% treated with Mg.
In the first step H20,N2. are removed by absorption.
The remaining gases are CO,CO2,H2= 30,+12,+ 30 Kg mole Treated with Ca =28.8 kg .mole CO+CO2 +112+ Ca = CaC2 +Ca + H21 CaC2+ H20 = C2H2 + CaO
CO+CO2 + 112 + 4Ca + H20 = C2H2 + 4Ca0 + H21' AH =- 426 K,cal C2H2 + 1121= C2H4 AH = -67 K.cal Total energy released = -493 K.cal Equivalent electricity obtained= 163 Kwh Product 15C21-14 = or 420 Kg per hr. OR Benzene 5 kg.mole and H2 Thus a basic series is started.
CaO is regenerated.
6Ca0 +4A1 = 2A1203 + 6Ca = 100 .000 Kcal 3Si02+ 4A1 = 2A1203 + 3Si -All =149,000 Thus for 6 kg moles of Ca0approx.3 mole silica is used to balance the energy requirement. This energy also includes energy require to volatile the Ca, and heat the circulating H2.
Ca formed is volatilized and re-start the reduction cycle The 4A1203 + 3Si formed go to the lower reactor Si is liquid but not volatile Si is filtered off the line and 4A1203 is reduced to Al and is recycled.
Energy is recovered as electricity =500 Kwh H2, CO are used to reduce 4A1203 .which is then recycled, Thus gain is C2H4, 420 kg.
Si 80 Kg.
Electricity =500 Kwh The Other 60 % gases are used by Magnesium cycle.
CO,CO2,H2= 30,+12,+ 30 Kg mole Treated with Mg =34.2 kg .mole 2C0+CO2 + H2 +6 Mg = Mg2C3 +4Mg0 + H21 Mg2C3+ 21120 = C3H4 + 2Mg0 2C0+CO2 + H2 +6Mg +2 H20 = C3H4 + 6Mg0 + H21 AH =- 591 K,cal C3H4 + H21 = C3H6 = -67 K.cal -13.4 +0.0 =-5 K.cal =6,=+ 8 K.cal Total energy released = -583 K.cal Equivalent electricity obtained= 194 Kwh Product 11C3H6 = or 462 Kg per hr.
OR C2114 C3H6= C51-110 + H2 = C5H12 a saturated proposed motor gasoline m.pt =36C
Thus a new basic series is started.
MgO is regenerated.
6Mg0 +4A1 = 2A1203 + 6Mg +MI = 40.000 Kcal 3Si02+ 4A1 = 2A1203 + 3Si -All =149,000 II
Thus for 6 kg moles of Mg approx.3 mole silica is used to balance the energy requirement. This energy also includes energy require to volatile the Mg, and heat the circulating H2.
Mg formed is volatilized and re-start the reduction cycle The 4A1203 + 3Si formed go to the lower reactor Si is liquid but not volatile Si is filtered off the line and 4A1203 is reduced to Al and is recycled.
Energy is recovered as electricity =500 Kwh H2, CO are used to reduce 4A1203 .which is then recycled, Thus gain is C3114, 440 kg.
Si 80 Kg.
Electricity =533 Kwh Si02 , A1203, MnO TiO2 are separated on treating with more Na20 Fe203 is separated magnetically The following CaO = 0.504 MgO = 0.336 SO3 = 0.042 P205 = 0.084 are changed into Ca2SiO4, Mg2SiO4, CaSO4, Ca3PO4.
Of the Si02 , A1203, MnO TiO2 Each one is separated individually And then the base zeolite of Si02 , A1203, is formed. in to this composition CaO is added for N2 adsorbing resin.
In to Si02 , A1203, base CuO is added for CO adsorbing zeolite.
There many varieties of zeolite all bases on SiO2, A1203, Annually from each oven 1000 Kg zeolite is made and from 49 ovens 49000 kg This gives revenue of about.98000 U.S $
Alternatively all ash is made water soluble by treating with acids and then complexed with EDTA. This is micro nutrient fertilizer and much required those soils using urea fertilizer. This will sell at about $5 per kg.

A hydro gel of sodium Aluminate sodium silicate is prepared in appropriate ratio .It is age few hours at about 100 C .The product is characterized by XRD, SEM, and FT-IR
techniques.
The crystal structure of the product was determined as zeolite X by XRD. The morphology of SEM image for zeolite X is octahedron shape and FT-IR bands are in accordance with the other characterization results.
Top gases Per oven per hour gases produced are 260 kg mole which contain which contain 2 kg.mole sulfur. It will end up 168 Kg CaSO4 .
Also heat is extracted from gases these are cooled from 1100C to 500 C.
The electricity generated is =1.Mw in one hour per oven.
Second Case: when gases from coke oven are supplied to thermal power plant and turbo-blower station.
Total gases produced:
Each oven is producing 195 Kg.mole per hour. The battery of 49 ovens is producing 195x49=10,000 Kg mole The capacity of the blast furnace is doubled. To 120 ton per hour. It will require 5000 Kg.mole of CO,H2 gases. The remaining 5000 kg.mole is used for the electricity production at the thermal Power plant. Which will produces 100 MW per hr.
Purified gases 5000 kg mole from battery area are sent to thermal power plant and the purified gases (freed from N2) CO2, H20 are returned to petrochemical generation area of figure 6.
Gases from thermal power plant should be counted in the addition the balance given above Some 5000 Kg moles from other battery are sent to alumina reduction in the cycle of figure 6.
We assume that each oven gasifies the charge mix (50% coal +50% household garbage) 25% of these gases are mixed with flue gases.
C2H4, 420 kg.
Si 80 Kg.
Electricity =500 Kwh C3H4, 440 kg.
Si 80 Kg.
Electricity =533 Kwh Summary of oven process when TPP-TBS is not included Inputs Output (50 % coal with 15 Gaseous out put per oven per hour =98 $198 % ash content and Kg.mole @ 100 50% house hold Per battery 49 oven is;z15000 kg mole garbage with 1% This whole production is supplied to ash contents) power plant.
1 tons per hour Zeolite = $90 Garbage has CaSO4 =
variable moisture FeO =
is made 50% by Electricity=

adding steam. N2=324 ton per hour Cost $30 per ton $60 Ethylene=420kg $880 average Propylene=440 kg On dry basis CO2= $80 02+52 kg mole Distilled H20=
per hour Si =160 kg 160 Si02 = $5 CO2, H20 to green houses CO,H2 =160x13 kg mole for recycling Al.
Total $65 $1408 Average Variable+ Fixed costs $ = 100 Administrative and sales expense $ = 7 Payroll over head = 6 Plant overheads = 15 Property taxes = 5 Labour charges $ =35 Energy Cost $ =15 Cost summary $181 Net Saving per oven per hour $1262 Oxygen plant is 80 ton oxy per hour it means two oxygen plants per battery 1000 tons per day standard plant Top gases Per oven per hour gases produced are 260 kg mole which contain which contain 2 kg.mole sulfur. It will end up 168 Kg CaSO4 =
Also heat is extracted from gases these are cooled from 1100C to 500 C.
The electricity generated is =1.Mw in one hour per oven.
Total gases produced:
Each oven is producing 195 Kg.mole per hour. The battery of 49 ovens is producing 195x49=10,000 Kg mole The capacity of the blast furnace is doubled. To 120 ton per hour. It will require 5000 Kg.mole of CO,H2 gases. The remaining 5000 kg.mole is used for the electricity production at the thermal Power plant. Which will produces 100 MW per hr.
Purified gases 5000 kg mole from battery area are sent to thermal power plant and the purified gases (freed from N2) CO2, H20 are returned to petrochemical generation area of figure 6. for the present the further processing of these gases is not considered. But the principals of processing is given under blast furnace slag processing.
Gases from thermal power plant should be counted in the addition the balance given above Blast furnace capacity is doubled the reduction gases required by blast furnace are about 3600 kg mole per hour. Some 25000 Kg moles are sent to alumina reduction in the cycle of slag utilization.

[

Annually from each oven 1000 Kg zeolite is made and from 49 ovens 49000 kg This gives revenue of about.98000 U.S $
Input raw materials are Coal per battery per hour 49 ton City garbage is 49 ton per hour Garbage or annual crops residue must contain 50% moisture.
Oxygen plants.51 tons/hr N2=200 tons per hour.
Out put Ethylene 420 kg Propylene 440 Hydrogen used It is more appropriate to treat coke ovens steelmaking, and power system TTP-TBS( Thermal Power Plant, Turbo-Blower Station) as one working complex. The power extracted from blast furnace off gases is done local, the slag is treated on spot but gases after electricity generations are taken to Coke oven area.
Coke ovens gave approximately 5000 Kg.mole to the Thermal power plant@ 2.2 $
/kg mole.
List of figures on fuel gasification, hydrocarbon gases and energy recovery 1 Figure 1 c.o. Showing new process at the ovens 2 Figure 2 c.o. A general layout of coke oven battery 3 . Figure 3.c.o. Purification of Oven gases

4. Figure 4 c.o. A zeolite for Nitrogen absorption

5. Figure 5 c.o. page lof2. Separation of CO, N2, H2 by different adsorbents Figure 5 c.o. page 2of 2A detail of absorption and heat removal of absorbents.

6 Figure 6.c.o.page lof2Petrochemical productions at coke-Ovens Figure 6 c.o. page 2of 2 Petrochemical production at coke Oven.

7 Figure 7 c.o. Recycling of A1203

8. Figure 8.c.o. Recovery of CO/CO2, H2/H20 from flue gases.

9. Figure 9.c.o A high technology Green house Iron making Plant A general set up of a conventional small size blast furnace BOF steel making route with apparatus units is shown in the following table.(About a million tons steel .per annum).
Main units Products Equipment Coke Oven and By- Coke 2 Batteries each containing products Plant 49 oven Sintering Plant Sinter 2 Sinter Machines Iron Making department Pig Iron 2 Blast furnaces Steel making Plant Cast Bloom, Cast Billet, 2 L.D. Convertors Cast Slab 1 Bloom caster , 1 Billet caster 2 Slab Casters Billet Mill Billets 800 mm reversible stand Hot Strip mill H.R. Coils/Plates 2 Reheating Furnaces 1700 mm stand Cold Rolling Mill C.R Coils/Sheets Four High reversible Galvanized ,Coils Sheets, machines Annealing H. R. Sheets furnaces Thermal Power Plant & Electricity 110 MW 3 Generators of 55 mm each Turbo-Blower Station Main Products: Coke, Pig Iron, Billets, Hot Rolled Sheets, Cold Rolled Sheets, Galvanized Sheets A zigzag route of making a mistake and then correcting it should be noticed.
Impurities containing Coke (Sulfur) is produced and when this is charged into blast furnace an impure inferior product is produced. Gases and charge are processed counter current in the blast furnace creating large blown out material so requiring the need of sintering (agglomeration) Next two steps namely BOF and Ladle processing are to rectify the previous mistake of iron making.
Steel is cast in large size ingots and blooms having internal and external defects so surface scarfing and reheating and size reduction, scale disposing is done until the product becomes appropriate for next operation rolling. Lot of cutting and re-joining is done producing defective portions.
The rolling operation is done in air and then storing in air. The rusted surface has to prepare by annealing and pickling to next operation of coating.
Pickling creates deep defects in steel structure.
Cold rolling is liable to produce micro-cracks in the internal structure of metal.
Against this Back ground in the presence process steel is produced using high purity gases and iron ore steel is produced directly .Unwanted ingredients in iron ore are slaged off. Alloying elements when desired are added after steel is formed in blast furnace.
Energy is recovered from liquid steel and it is directly made into appropriate to perform next operation. Near net size products are produced which are given on line heat treatment in controlled atmosphere. The steel is brought in to air after required surface protection has been performed. On line heat-treatment eliminates the cold rolling.
Intermediate cutting is seldom performed where there is need of certain relaxation between two operation closed atmospheres accumulators are provided, List of Figures On steel making and rolling Figure 1.sm Blast furnace Plan at Elevation 9.2 M hearth floor.
Figure 2.sm page lof 2 More details of the hearth plan.
Figure3. sm. Three Units in a set tundish, refractory filter, micro-particles formation Figure 4.sm Micro-particles steel carrier to shaping and rolling lines. An alternate to Figure 5.sm page 1 of 3 Figure 5.sm page 2 of3 Near net shape die casting Figure 5 sm. page 3 of 3 Extruding and casting of oxygen free ceramics Figure 6 sm. Steel plate rolling operation with thermo-mechanical treatment.

Page lof 2 Figure 6 sm. Steel plate rolling operation with thermo-mechanical treatment.
Page 2of 2 Figure 7 sm. Page lof3 Figure 7 sm. page 2of3 Figure 7 sm. page 3of3 Briefly stated conventional iron making in blast furnace process is changed to steel making.
Most of the virgin liquid steel is made through this route consisting of agglomeration (sintering), blast furnace, basic oxygen furnace to continuous cast. Our aim is to describe these conventional processes and then and describe a new short cut route of direct steel making to casting and rolling.
A Blast Furnace is iron making process in which iron ore in the form of sinter or pallets or graded lump iron are charged in binary or tertiary combinations.
Mostly a combination of sinter and graded lump iron ore is used. Fuel is coke made from metallurgical coal. Most of the slag forming flux is added during the sintering operation such but balancing additions (limestone plus dolomite) are made in the blast furnace along with charge. It is reduction smelting operation where certain degree of pre-reduction of the charge is achieved before it reached in the melting zone.
Most of the metals are reduced and join with the liquid iron accumulated in the bottom of the furnace.
A preheated blast of air is introduced in the furnace for the purpose of reduction smelting.
To reduce coke rate natural gas is added in the furnace, and air blast is enriched with oxygen.
The following information of the blast furnace operation is given to design new apparatus Blast Furnace operating conditions Table 4.2 Hot Blast Temperature 1100 C
Blast Moisture 8 g/ cu.m Oxygen contents 21 % by Volume Blast Pressure 1.5 bar Air required 1570 cu.m / steel Top gas Temperature 300 C
Pressure 3.5 bars Melting rate of furnace in terms of tons of coke (w.b.) burnt per 1 cu.m of furnace effective volume per day is 0.96 Top gas analysis Carbon dioxide 16.

CC
Nitrogen 55.

Top gas volume 2070 cu.m /thm Approximate technical Characteristic of Blast Furnace melt.
Table Description Unit Value Consumption of raw materials (w.b.):
Skip Coke kg/ton of hot metal 564 Fluxed sinter Lump ore 657 Hot Metal Analysis Fe 93.45 Silicon 0.7 Manganese 46 1.2 Phosphorus 0.11 Sulfur 66 0.03 Carbon 4.5 Copper, etc. traces Temperature C 1530 Slag Analysis Silica 37.2 Alumina 10.5 Titanium dioxide 46 0.8 Calcium Oxide 39.1 Magnesium Oxide 8.0 Manganese Oxide 1.3 Manganous oxide 66 0.3 Ferrous oxide 0.5 Alkalies 0.5 Sulfur 0.6 Rated slag weight Kg/ton hot metal 428.6 Table 4.5 Flue dust production (recovered) Kg. / ton hot metal 25 Scrap production 44 10 Effective volume utilization factor t/day 1750 Out put of iron making plant thou. t. / yr. 1,250 In modern blast furnace producing about 10,000 ton of hot metal per day on charge of sinter and acidic pellets ((90,10%) the coke rate is about 478 kg./hot metal and slag volume is 279 Kg.. Their top pressure is 1.5. bar and top temperature is 150 C. These have energy recovery by turbines from top gases.
Every bit of energy recovery is made, simultaneously increasing equipment input.
The small size iron making plant comprises following facilities.
Set up of Iron Making Plant.

The small size plant under discussion consist of two 1033 cu.m internal volume furnaces with related ancillaries (cast houses and bottom houses, block of hot blast stove, dust catchers, top skip hoists, b.f. control pulpit buildings, etc.).
Large size furnaces have conveyor charging and bell type charging replaced with continuous charging system. They have energy recovery from high pressure at the top exit.
The systems under discussion have:
-Burden bins with skip pits over bin conveyor gallery of raw materials delivery system and equipment for fine sinter and coke breeze removal.
-Substation of blast furnace 1 and 2.
Hot metal relining and slag dressing ladles.
.-Air supply and aspiration system -Oil supply system Administration building and laboratory.
-Hot metal ladles 20 and slag ladles about 15.
Top Construction.
For repair or erection top plat form has 100 ton electric crane supported on the furnace top and top of the dust catcher. It can carry the full assembly and place it on exact coordinates with auxiliary winches.
The main equipment on the furnace top are:
-Charging device with large bell of 4600 mm diameter and 36 cu.m space between the bells.
- burden distribution with the revolving hopper effective volume of 8. cu.m and the small bell diameter of 2200 mm.
- bell beams and four 300 mm diameter equaling values with build-in electric drives designed for pressure equalizing in the space between the bells before they are levered.
-Two chains tests for measuring stock line level.
Passage are provided for connecting the furnace top with the lift, inclined bridge and dust catcher.
Cast House and Bottom House Building.
It consists operating platform of the building and four railway tracks for hot metal, slag and auxiliary cargo. The building has 30 ton E. O.T. cranes operating over the cast house.
And 10 ton crane in the slag area. A runner for hot metal two runners for slag. Slag and hot metal ladle may be remote operated.
Tapping of the furnace 1750 tons per day times 8 tapping of hot metal will require three 140 tons hot metal ladles three 16 cu.m slag pot cars. For slag tapping through slag notch two slag cars are required.
All furnace operation opening and closing of taps and operation of snort valve are done from the control room.
Blast Furnace and Hot blast Stove Control Center Three storey 12 m wide control building is directly connoted with operating platform of furnace and the stoves.
On the third storey which is at same elevation as furnace operating platform are located main control board with control and measuring instruments, furnace charging light signal, operating board of the furnace panel for natural gas feed to tuyres. Here are also located the winch as operating the dust catcher shut-off valve, the furnace bleeder valves and the dust catcher bleeder and dust valves.

On the second storey at the elevation of 6500 mm are hot blast stoves control panel boards, grease lubrication stations, coolant supply inlets, laboratory, repair room for control and measuring instruments.
On the first storey are at floor level are filters, with gate valves for cleaning the water facilities to the furnace. And section for transformer substation supplying to b.f and stoves.
Operation and equipment changes in the blast furnace for direct production of steel and elimination of wastes:
Figure .1 Shown is plan at 8.8 meters which is liquid metal discharge bottom. The furnace floor level is raised by refractory lining so that no metal pool remains in the furnace when the furnace is desired to be made empty. The liquid steel level in the discharge trough few centimeters lower than furnace floor level. The through can be made empty by a bottom hole when desired, The circular trough length is made large enough that it is 3-4 meters to the opening in the hearth floor. The level of steel is approxØ5 meters and level of slag channel is above this height. It can have additive pipe near the exit and gases off take near the slag channel There can be two steel holes discharging steel. Steel is discharged to a tundish from which any slag goes to slag channel.
The tundish discharges steel to a filtering vessel which retains any inclusions. Both tundish and filtering vessel have quick changing means.
The filter refractory floor has appropriate sport for strength.
Thin liquid streams coming out of filtering vessel are met with cold Nitrogen and are made to drop bellow solidification point to 1350-1400 C.
The micro particle channel goes to steel lined over refractory vessels and transported to continuous extrusion presses.
1. Blast furnace bottom. At 8.8 meter elevation.
2. Liquid steel and slag discharge trough.
3. Steel discharge hole 4. Steel discharge hole.
5. Extension trough upto to open in heath floor.
6. discharge pipe into tundish 7. Tundish slag going to furnace slag.
8. Steel from tundish flowing into filtering vessel.
9 Micro particle channels valves Furnace Top Operation of large bell is stopped and its sealed a platform is welded near the top of bell and charge is introduced into the furnace by screw feeders at constant rate. The small bell is open all the time and it directly supply charge to the screw feeders.
The operation of charge trolley is kept as usual, No coke is charged, Only small size ore about 3 mm size is charged.
Gas uptake is closed and reduction gases are introduced into the furnace through one of them. Measurement instrument are placed in the other. Also oxygen about 10% of the reduction gases is introduced .The gases and particles follow co, current down ward to the slag region where hot air blast is introduced through the tuyers. All ore particles are melted and hot gases flow through the side channel to heat recover region the out going gases from heat recovery go to CO2,H20 recovery which are used for hydrocarbon gases Manu facing.
Slag flow to slag railways area where it's introduced into high temperature reactor simultaneously with Al. met with slag processing cooled with water and separated into water soluble sodium melt salts. and water insoluble Ca ,Mg silicates and further process as explained under coke oven section, for the preparation of zeolite or separation of high quality A1203 for market.
. Techno economic comparisons of new direct steel making route and conventional Blast furnace, Basic oxygen furnace route In the direct steel making (DSM) route all steps are forward to final product.
In the blast furnace basic oxygen furnace route (BF-BOF) A step is taken sintering forward a dirty product is obtained (liquid metal from BF)and then some steps are taken to clean that product ( BOF, Laddle metallurgy), before the net forward step is taken Conversion cost for BOF steel making route.
Integrated steelmaking -crude steel cost model Item$/unit Factor unit Unit cost Fixed Variable Total Iron ore 1.508 t 98 147.8 147.8 Iron ore 1.508 t 9.25 13.95 13.95 transport Coking coal 0.877 t 142 124.5 124.5 Coking 0.887 t 13.25 11.6 11.6 Coal transport Steel scrap 0.141 t 340 47.9 47.9 Scrap 0.141 t 5 0.71 0.71 delivery Oxygen 141 1\43 0.095 13.4 13.4 Ferroalloys 0.014 t 1175 16.45 16.45 Fluxes 0.497 t 50 24.85 24.85 Refractories 0.009 T 648 5.47 5.47 Other costs 1 15 3.75 12.25 15.00 By product -31.8 -31.8 credits Thermal -7.69 GJ 15.0 -115.3 -115.3 energy net Electricity 0.142 MWh 181 3.9 21.8 25.7 Labour , 0.65 Man hr 37.7 6.1 18.4 24.5 Capital 56.7 56.4 charges Total 70.1 311.4 381.5 Steel cost-2014 basic oxygen furnace route steel making cost-BOF
http:// www steel onthenet.com /cost- bof.html.

Conversion cost for BOF steel making route.
Integrated steelmaking -crude steel cost model Item$/unit Factor unit Unit cost Fixed Variable Total Iron ore 1.508 t 98 147.8 147.8 Iron ore 1.508 t 9.25 13.95 13.95 transport CO,H2 66 66.
gases from oven process Steel scrap Scrap delivery Oxygen Ferroalloys Fluxes Refractories 0.009 T 648 5.47 5.47 Other costs 1 15 3.75 12.25 15.00 By product -37.2 -37.2 credits Thermal - -20 -20.
energy net Electricity 0.142 MWh 181 3.9 21.8 25.7 Labour 0.65 Man hr 37.7 6.1 18.4 24.5 Capital 56.7 56.4 charges Total 70.1 230.9 297.3 Difference 484.2/ton At blast furnace exit there are three lines to be treated.
1.Liquid steel: Energy is to be extracted from it and it is made suitable to under go shaping , rolling and finishing process.
2. Liquid slag: Energy is to be extracted from it and useful ingredients from it extracted for market purposes.
3.Exhaust gases High temperature energy is extracted and useful gas ingredient reutilized.
Liquid steel from product trough is teemed to a tundish any slag is separated and diverted to slag line. Steel is filtered from inclusions and it made into micro-particles and cooled by nitrogen down to 1300C.The hot nitrogen is taken to energy recovery system of the plant.

The micro-particles are collected in a carrier vessel which is a refractory ladle covered with steel sheet and also covered with refractory lined steel roof. It is transported to rolling mill area where it is connected to an extrusion system. Its lower valve feeds the micro-particles to the extruder. After discharging it return for refilling.
2. Liquid slag is discharged to a refractory vessel where other material for energy extraction and chemical formation are added.
The slag ingredients are Si02, A1203, CaO,Mg0, MnO,P205 ,S03 ,TiO2 and minute quantity of others.
Top gases are passed through heat extracting Gas turbine and then gases are separated from N2 and any other.
These are CO2,H20 of the product gas which are treated with slag ingredient to extract C and H2 ingredient from these.
Hot slag is dropped into a refractory lined high temperature reactor where Al and Si02 are added along with H2...
The reaction schemes and flow process are describe below and explained on the diagram figure We take half of exit CO2,H20 gases 250 Kg mol .100 Kg mole are reacted with Ca and 150 Kg with Mg.
3/4 of CO2 is liquidified and supplied for city uses and green houses.
50[2C 02 +5Ca + H20 = C2H2 +5 CaO -AH = 450 K.cal Kwh =150]
50[3C 02 +8Mg + 2H20 = C3H4 +8 MgO -AH = 662 K.cal Kwh =220]
C2H2, 50 Kg.mol Total electricity =66 MW
Total slag ingredients + Ca CaO 22.5 tons added out side MgO 24 tons CaO, is =250 kg mole Both pure white +Si02 =30 tons powders 30 tonsx15 = 450$ Mg @100/ton $4600 Mg0SiO2=400kg.mol 16+16 tons x15 A1203 recycled =480$ Si 650 Kg.mol Al =30 Tons @$1.5 27300 Recycled Electricity 66MW @ $
90/mw 5940 Toluene Acrylic acid 150 Net 37200 Steel produced @ 600x60 36,000 Alumina recycled is 13000 kg CaO, MgO and Si are not recycled.A1203 is recycled at the cost of 13.5 Kg.mole per Kg mole alumina Half of oxygen require is supplied by alumina.
Conversion cost model-Slab to hot Rolled coil HSM- Typical costs per tonne Typical hot strip mill conversion costs Item $/Unit Factor Unit Unit cost Fixed Variable Total Slab 1.035 T 500 517 517 Slab Transport 1.035 T 5 5 5 Manpower 1.0 MHPT 20 5 15 20 Natural Gas 1.5 GJ 9 14 14 Electricity 60 Kw/H 0.07 4 4 Work Roll n/a T 1 1 , 1 Consumables 2 2 2 Yield loss 0.035 T 46 2 2 Scrap Credit 0.035 T 350 (12) (12) Depreciation& 10 10 10 Others Sg&A Costs 5 5 5 Total HRC 20 548 558 Steel Cost model ¨hot rolled coil conversion costs-lire http://www.steelconthnet.com/cost-hre.html Producing New inter-metallic compound alloys:
Tertiary components can be devised forming inter-metallic compound of extra high strength non corrosive properties. These are non oxygen ceramic combining with steel, chromium, nickel ,manganese ,aluminum and refractory metals.
Non oxygen ceramic are silicon carbide .silicon nitride, and aluminum nitride, In the extrusion die in the beginning area silicon, carbon and third metal or silicon, nitrogen and third metal are introduced and extruded like single metal of steel or others. ( third metal is one from above metals). As silicon nitride is formed at 1300C
but not steel which will act as intra particles ductile phase. Thus new series of alloys is introduced.
Processing power plant gases It was pointed out in coke oven section that some 5000 Kg mole product gases are obtained .These gases are CO2 and H20 on equal molar basis. So 2500 CO2 Kg.mole are processed.
Ca material is obtained from calcium silicate the ratio of CaO and Si02 are adjusted as 2 to 1 and Al is added for energy balance as following 6 CaO +3 Si02 +8A1= 6Ca +3Si + 4A1203 AH = -50. 000 K.cal 9 MgO + 3Si02 + 10A1 = 9Mg +3Si + 5 A1203 AH =-89 ,000 Kcal.
Of the CO2: 1000 Kg mole are reacted with Ca 500[ 2 CO2 +5Ca + H20 = C2H2 +5 CaO AH =450,000 =150kwh]

, 500[ 3 CO2 +8Mg + 2H20 = C3H4 +8 MgO AH =-46620,000 =220kwh]
500[C2112 +5 CaO 150kwh]
500[C3H4 +8 MgO 220kwh]

H2 required to form saturated 500 C5H6 = 500[3H2]
Electricity formed 370x 500 = 185 MW
CaO 500 x5 x56 = 140,000 kg MgO 500 x 8x 40 =160,000 kg C5H12=72 x500 = 36,000 kg Si =5x 500 Kg.mole =78999 kg A1203 recycled. 7.7 Kg mole {for 5 CaO +8 MgO) Total 7.7x500 = 3850 kg.mole. or 208 tons per hour Aluminum units are more convenient to handle 25 tons per hour.
So CO2 200 for Ca and 300 for Mg. is handled the rest is transferred to green houses or liquidified for consumers Approximate return from this reduced size CaO 50 x5 x56 = 14,000 kg @$100/ton =1400 MgO 50 x 8x 40=16,000 kg =1600 C5H12=72 x50 = 3,600 kg =3600 Si =5x 50 Kg.mole =7899 kg =15800 Electricity 40 Mw =3600 A1203 recycled. 7.7 Kg mole {for 5 CaO +8 MgO) Total 7.7x50 = 385 kg.mole. or 21 tons per hour =$26000 720 Kg mol alumina { this will require 13.5( CO,H2) x720 Kg.mol or 9350 kg mole oxygen Half of this will be external oxygen. Or 150 ton of oxygen per hour)or about 300,000 ton aluminum plant per annum.
CO2+ H20,0igho = Plant Growth = Fuels = CO2 Definitions Pyrolysis: Decomposition of organic material by the action of heat.
Gasification: to change into gases by heating with chemical reaction.

Claims

Claims 1.
New operational role is assigned to coke ovens.
- from a charge of coal and carbonaceous material and oxidizing gases (Oxygen or oxygen plus nitrogen) reducing gases or reducing gases containing small percentage of oxidizing gases are produced within a oven. The ashes from charge materials are left at the bottom of the oven.
The ashes and product gases are made to flow out of the oven from a hole near the oven bottom on the coke side of the oven. The Coke door is closed with refractory.
The coke pusher action is stopped.
From the top holes on the oven top coal and carbonaceous materials is continuously charge by screw feeders fro charge bins over these holes.
-previous gases off takes are used inlet for Oxygen and steam or CO2.
Thermocouples and pilot flames are also provided through these holes.
Oven floor is made inclined so that coal ash flows out by inclination.
Ash and gases flow out together from the hole, from where gases go to the top to the previous gas off takes and ashes are made to flow out through control means to a collector.
Coke trolley now collect the ash after intervals and take to processing station previously coke quenching station.
Gases go to energy recover and purification set up. Here chemical compounds are produced from impurities in the gas. Chemical compounds are prepared for market, Solid ashes are freed of FeO and rest of the mass is changed to micro nutrient fertilizer or zeolite compounds.
Oven product gases are CO,H2and small percentage of N2. These may be separated into CO,H2 and N2 gases and then further used as desired .
2.
- A blast furnace is changed to co-current flowing rector for charge and gases, both flowing from top toward bottom.
-At the bottom liquid metal and slag are formed -Down coming material melt at the slag surface and product gases flow out of a side channel to upward for energy recovery and when the gases are near ambient temperature CO2 and H2O are recovered as purified gases from other product gases.
-The of heat recovery process acts as an electricity production unit.
-No solid particle flow out with gases.
-From the furnace out let three material namely steel, slag and product gases flow out which are led to different processing lines.
-Hot slag is introduced into a high temperature reactor where if required more slag forming ingredient namely CaO, MgO, SiO2 and liquid Al are added. Circulating H2 is also introduced. Volatile components Ca, Mg are gone out along with H2 from the top to fractionating columns: Ca in first column, Mg in next column and then if Zn, Na, and P
are present in next successive columns.
-SiO2 is reducing to Si but being non volatile will flow down ward along with Al2O3 which has formed in the exothermal mutual reactions.
-In a lower reactor Si is filtered from Al2O3 which goes to a reduction reactor .Here Al 2O3 is reduced to Al and energy is recovered from product gases CO2, H2O .

Al is recycled to perform the above described reactions.
-The CaO SiO2 or lime stone and MgO SiO2 Magnesite and similar material from slag are cheap materials which in the process become valuable Ca, Mg, and Si.
Ca when react with CO2 and then H2O (if CO,H2 are available these can be included) form C2H2 and CaO. The reaction being highly exothermic will also supply energy for power generation. Similarly Mg when react with CO2 and then H2O (if CO,H2 are available these can be included) form C3H4 and MgO .The reaction being highly exothermic will also supply energy for power generation.
The CaO and MgO formed are highly valuable and have market value. Thus from cheaper material valuable materials are obtained along with slag disposal, Al and Al2O3 in cyclic are engine for change.
C2H2 and C3H4 are used to form cyclic aromatic Toluene , Benzene or Xylene. Or straight chain ethylene and propylene with more use of H2 . These can further under go mutual condensation, cross condensation or reaction with other chemical to form endless chemical, polymer, gasoline, diesels, waxes, dyes etc. .
3.
The steel produced from Blast furnace is interstitial free steel (IF) to produce other steel alloying element are added. Those alloying element which are reducible with or before Iron are added in the charge.
-Those elements which are not reducible with iron are added in the trough after blast furnace exit in reduced form.
4.
Next three steps are to prepare the steel for final shape forming eliminating the big structures formation (blooms etc).Steel is passed through any impurity removal( tundish, filter) and then forming micro particles by cooling with nitrogen at about 1300 C.
-the stable particles are free of internal and external defects and can ne transported with picking up any impurity.
These particles are taken to the extrusion set ups at the head of rolling, casting facilities.
Near net shapes are extruded in plates, H shapes. Strips, Angles, Rails or any other shape at 1300 -1400C. These enter a chamber for cooling about 200 C and then taken up by shaping equipment in closed atmosphere.
- when the final product is plate it given a heat treatment rolling and then cut and pushed in side arrangement for coating and annealing All shapes like H shapes are given similar treatment like plate.
7.
A shape or dimension is changed at the extrusion die.
The extrusion die is high strength steel cylinder lined with dolomite refractory mono-lithically formed from dolomite solution in acetic acid.
It has embedded heat coils for temperature adjustment. It has pushing screws internally cooled with cold nitrogen. It has powerful gear motor arrangement for reach high compression for material to be pushed from 1200 to 1400 C.
The extrusion dies are made from silicon carbides externally adjustable for appropriate dimension of the extruded material, 8.

When the final product is strip it is rolled in an other group of rolling stands simultaneously temperature being adjusts to reach the exit temperature.
The strip may be taken to a lower level where coil formation and subsequent operation are done.
The strip may be taken straight and cut to required length and piled for annealing and shipment.
When the strip is meant for galvanizing the strip is passed though coating facilities before final cooling coiling or cutting.
9.
New extrusion lines for oxygen free ceramics. Silicon carbide, Silicon nitride, aluminum nitrides are started here. Which due to light weights and extra strength are expected to get some shear from steel.
These silicon and aluminum material are produced as in claim 3.
10.
No intermediate cutting and joining is done. Where flexibility in operation is required accumulator are provided under protected atmosphere.
11.
Nitrogen can be used as protected atmosphere for steel at temperature above 1000C.
below this temperature Argon is the protective atmosphere, backed by cold Nitrogen in second enclosure.