KR20020049889A - apparatus for recycling self-generated sludge in non-coking coal and fine ore based ironmaking - Google Patents

Abstract

PURPOSE: An apparatus for recycling self-generated sludge is provided to increase productivity of the iron ingot manufacturing facility by adding a certain amount of the sludge to a high temperature lump iron manufacturing facility, thereby charging the sludge into a melter gasifier for recycling. CONSTITUTION: The apparatus for recycling self-generated sludge in an iron ingot manufacturing facility using non-coking coal and fine iron ore comprises a dryer(101) sludge that is discharged from a dehydrator(100) and solidified; a pulverizer(102) pulverizing the dried sludge discharged from the drier(101) into a powder shape having grain size of 1 mm or less; a classifier(103) classifying the pulverized sludge powder into a certain grain size; an upper storage hopper(104) in which sludge powder is stored, into which nitrogen gas is supplied through a nitrogen supply pipe(205) so that an inner atmosphere of the upper storage hopper(104) is maintained to the inert state, and on an exhaust port of which a dust collector(105) is mounted; a lower storage hopper(108) which is connected to the lower part of the upper storage hopper(104) by means of a flexible pipe(106) and a cutout valve(107) and equipped with upper and lower level switches(111,112) detecting high and low levels of sludge powder supplied through the cutout valve(107), and on which a weight measuring instrument(109) continuously measuring weight variation of the injected sludge powder is mounted; a rotation discharger which is installed at the lower part of a discharging port of the lower storage hopper(108) to control a discharge amount of the sludge powder as controlling the number of revolutions according to signals of the weight measuring instrument(109); and a blowing pipe(24) supplying the sludge powder discharged from the rotation discharger to a third ore pipe(203) using nitrogen gas.

Description

Apparatus for recycling self-generated sludge in non-coking coal and fine ore based ironmaking}

The present invention relates to an apparatus for recycling by-product moist sludge in molten iron manufacturing equipment using ordinary coal and iron ore, and more particularly, as a process dispersion in the process of manufacturing molten iron using ordinary coal and fine iron ore. In the process of manufacturing molten iron using ordinary coal and iron ore, which can reduce the external discharge amount of the final sludge and reduce the treatment cost and improve the process productivity by enabling the recycling of iron and moisture sludge to the process itself. It relates to a by-product sludge recycling apparatus.

In general, the blast furnace method, which is widely used in molten iron production facilities, has a certain level of strength due to the characteristics of the reactor, and requires raw materials having a particle size that can ensure the breathability of the furnace. As a carbon source used as a fuel and a reducing agent, specific raw coal is used. Processed coke is used, and as iron source, it mainly depends on sintered ore which has undergone a series of hardening processes.

Accordingly, the present blast furnace method must be accompanied by raw material pretreatment facilities such as coke manufacturing facilities, raw material coal, sintering facilities for compacting ores, pelletizing facilities, etc. The competitiveness of the current blast furnace method is rapidly being eroded by the enormous investment costs for environ- mental pollution prevention facilities to overcome global regulations on environmental pollutants generated from facilities.

In order to cope with the above situation, countries around the world directly use general coal as fuel and reducing agent, and as a source of iron, develop new steel making process using molten iron ore, which accounts for more than 80% of the world's ore production. Spurs on

The molten iron manufacturing equipment using the conventional general coal and iron ore directly related to the above technology is disclosed in US Patent No. 5,534,046.

According to the above publication, the overall process is as shown in Figure 1, three stages of the fluidized reduction reactor and the coal-filled bed consisting of a preheating furnace (2), preliminary reduction reactor (3) and the final reduction reactor (4), etc. Consisting of a molten gasifier (1), the iron ore (hereinafter referred to as spectroscopy) at room temperature continuously charged into the preheating furnace 2, which is the uppermost reactor, is referred to as the first, second and third ore conduits 201. High temperature is supplied through the first and second and third gas pipes 301, 302 and 303 from the melt gasifier 1 while sequentially passing through the three-stage flow reduction path through 202 and 203. It is converted into a high-temperature reduction spectroscopy having a temperature rise and a reduction of 90% or more by contacting a reducing air stream, and the reduction spectroscopy is continuously charged into the molten gasifier 1 in which the coal filling layer is formed, and is then discharged in the coal filling layer. As it is melted, it is converted into molten iron and discharged outside the molten gasifier 1. .

In addition, in the melting gasifier 1, bulky coal is continuously supplied from the upper part of the furnace to form a coal filling layer having a constant height inside the furnace, and a plurality of tuyere formed at the lower end of the filling layer outer wall. Oxygen is blown into the packed bed through the coal, and the coal is burned in the packed bed, and the combustion gas is converted into a high temperature reducing air stream while raising the packed bed, through the first gas pipe 303 of the molten gasifier 1. While a part is discharged, it is supplied to the three-stage flow reduction reactor, while a part is discharged out of the process through the water treatment facility 6 so that the pressure applied to the melt gasifier 1 is kept constant.

In the reduction reactor, the flow reactor described above, the final flue gas and the flue gas for pressure control of the molten gasifier 1 pass through the collecting facilities 6 and 7, respectively, and come into contact with the process water continuously supplied from the collecting facility. After the water is removed and cooled, the process water is discharged separately from the process water, and the discharged process water, which is separated from the gas from the collecting facility 6 and 7, is contained inside the water treatment facility 8. Dust is removed and reused.

The movement of each flow reaction period of the ore through the three-stage flow reduction path is carried out by the first, second, and three ore ore ore conduits 201, 202, and 203 connecting the flow reduction paths adjacent to each other. In the conduit 201, 202, 203, the upper and lower flow reduction of the upper flow by the high temperature reduction gas flow and gravity formed from the lower flow reduction to the upper flow reduction path by the pressure difference between the upper and lower ends Ore flow formed from the flow reducing path from the bottom is formed to cross each other.

On the other hand, as a method of charging the reduced reduction iron continuously discharged from the final reduction path (4) into the molten gasifier (1) using a portion of the high-temperature reducing gas supplied to the three-stage flow reduction reactor as a transport gas And charged into the molten gasifier (1) and charged into the molten gasifier (1), and reduced iron is produced as a high-temperature iron oxide (HBI) manufacturing apparatus (5), and the molten gasifier is manufactured using a separate transfer facility ( The method of charging after transferring to 1) is proposed, but the latter is applied to the commercial facilities of the process currently being promoted.

On the other hand, in the above process, a large amount of dust is contained in the process by-product gas due to the role of ordinary coal in the melt gasifier and the spectroscopic differentiation in the flow reduction reactor, and thus, the by-product gas collector facility ( 6) (7) is a by-product of the water treatment plant (8) of the process water circulated and used, and a large amount of moist dust (hereinafter referred to as sludge) is generated, which is about 200 tons per day based on the 2000 tons daily production facility. Is coming.

As shown in Table 1, the by-product sludge contains a large amount of carbon and iron components.

Sludge Composition (Dry Basis) T.Fe Carbon Ash Content rate (%) 24.7 38.2 38.1

Currently, more than 90% of the by-product sludge is buried, and the burden of landfill costs and environmental pollution is increased in the conventional sludge treatment method, and carbon and iron contained in the sludge can be reused. Despite this, it will be discarded. Therefore, when the by-product sludge is reused in the process itself, the treatment cost is reduced by reducing the by-product sludge emission, and the production cost is reduced by utilizing carbon and iron in the sludge to improve the overall productivity of the process. It can be increased.

Therefore, the present invention has been made to solve the above problems, the purpose is to dehydrate, dry and crush the by-product sludge produced in the process of manufacturing molten iron using ordinary coal and iron ore and together with the reducing iron Provides by-product sludge recycling apparatus in molten iron manufacturing equipment using ordinary coal and iron ore that can increase the productivity of molten iron manufacturing equipment by mixing up to a certain amount in the high temperature lump iron manufacturing equipment so as to be agglomerated and recycled. I would like to.

1 is an overall configuration diagram showing the by-product sludge recycling apparatus in the molten iron manufacturing equipment using the coal and powdered iron ore according to the present invention,

Figure 2 is a detailed view showing the distal end of the sludge powder pneumatic conduit inserted into the reducing iron loading conduit in the by-product sludge recycling apparatus in the molten iron manufacturing equipment using the coal and powdered iron ore according to the present invention.

Explanation of symbols on the main parts of the drawings

2 ..... Preheating Furnace 3 ..... Preliminary Reduction Furnace

4 ..... Final Reduction Furnace 5 .....

100 .... Dehydrator 101 .... Dryer

102 .... Crushers 103 .... Classifiers

104 .... Upper reservoir 105 .... Lower reservoir

106 .... Expansion pipe 107 .... Shut-off valve

203 .... Third Ore Conduit 205,206 .... Nitrogen Supply Conduit

As a technical configuration for achieving the above object, the present invention

It consists of a preheating furnace in which the reduced iron ore flows in and is reduced, a preliminary reduction reactor, a final reduction reactor consisting of a three-stage flow reduction furnace, a high temperature annealing iron manufacturing apparatus connected thereto, and a molten gasification furnace connected thereto, and between the flow reduction reactors. A first ore ore conduit through which the flow of ore and reducing gas flows, and a third ore conduit connecting between the final reduction path and the high temperature annealed iron making apparatus, and the exhaust gas conduit and the melt In the molten iron manufacturing equipment for manufacturing molten iron having a collector installed in the rear end of the pressure control exhaust gas conduit and a water treatment device connected to the collector,

A dehydrator for removing and solidifying water contained in the sludge discharged from the water treatment apparatus; A dryer for drying the sludge discharged from the dehydrator; A crusher for crushing the dried sludge discharged from the dryer into a powder having a particle size of 1 mm or less; A classifier classifying the sludge powder crushed by the crusher into a particle size of a predetermined size; An upper storage tank in which the sludge powder discharged from the classifier is stored, nitrogen gas is internally supplied through a nitrogen supply pipe to maintain the internal atmosphere in an inactive state, and a dust collector is installed at an outlet through which the supplied nitrogen gas is discharged; It is connected to the lower end of the upper reservoir via the expansion pipe and the shutoff valve, and equipped with upper and lower level switches for detecting the high and low level of the sludge powder supplied through the shutoff valve, and continuously changes the weight of the injected sludge powder A lower reservoir equipped with a weighing instrument for measuring with; A rotary extractor installed at the lower outlet of the lower reservoir to control the discharge of the sludge powder while adjusting the rotational speed according to the signal of the weighing instrument; By-products in the molten iron manufacturing equipment using coal and iron ore characterized in that it comprises a pneumatic conduit for supplying the sludge powder discharged from the rotary extractor as nitrogen gas supplied through the nitrogen supply conduit to the third ore conduit. By installing a sludge recycling system.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is an overall configuration diagram showing the by-product sludge recycling apparatus in the molten iron manufacturing equipment using a coal and powdered iron ore according to the present invention, Figure 2 is a molten iron manufacturing equipment using a coal and powdered iron ore according to the present invention A detailed view showing the distal end of the sludge powder pneumatic conduit inserted into the ring reducing iron charging conduit in the by-product sludge recycling apparatus.

1 and 2, the apparatus 200 of the present invention is a large amount contained in the exhaust gas in the collecting device (6) (7) installed in the exhaust pipe exhaust gas by-product generated during the process of manufacturing molten iron To remove the dust and to recycle the sludge as a by-product generated in the water treatment apparatus 8 for treating the removed dust as process water, such apparatus 200 is a dehydrator 100, dryer 101, crusher 102 ), A classifier 103, upper and lower reservoirs 104 and 105, rotary extractor 11 and the like.

That is, the dehydrator 100 is supplied with the sludge discharged to one side separated from the process water in the water treatment device 8 as the conveyor belt (100a) to remove and solidify the water contained in the sludge. At this time, the water content of the sludge is controlled to within 10%.

In addition, the dryer 101 is installed at the outlet side of the dehydrator 100 and is supplied with the sludge solidified by the dehydrator 100 and dried so that the water content of the sludge is within 1%, and the outlet side of the dryer 101. The crusher 102 installed in the dehydrator 100 and the dryer 101 is to crush the dried sludge in the form of a powder having a particle size of 1mm or less while passing through the water.

In addition, the classifier 103 is installed at a position that is crushed by the crusher 102 falls to the exit side, the sludge of 1mm or less, which is a reference value set by classifying the sludge in the form of powder falls into the lower portion, 1mm which is the set reference value The above sludge is circulated and supplied to the crusher 102 side.

In addition, the upper storage tank 104 is a nitrogen supply conduit 205 which is supplied with nitrogen gas in the vicinity of the lower to maintain a predetermined amount of sludge powder is dropped and discharged from the classifier 103, the inner atmosphere in an inactive state Communicating is connected, the discharge port discharged nitrogen gas supplied to the inside is equipped with a dust collector 105 to prevent the sludge powder is discharged to the atmosphere together with the discharge gas.

In addition, a lower reservoir 108 is installed at the lower end of the upper reservoir 104 via a flexible tube 106 and a shut-off valve 107 capable of upper and lower shafts, and the shutoff valve 108 is disposed at the lower reservoir 108. The upper and lower level switches 111 and 112 are mounted to detect the input amount of the sludge powder of the upper reservoir 104 supplied through the expansion pipe 106 during the opening operation of the 107, and the injected sludge powder Equipped with a weighing instrument 109 to continuously measure the weight change of the.

On the other hand, the lower outlet of the lower reservoir 108 is provided with a rotary extractor 11 for appropriately controlling the discharge of the sludge powder while adjusting the number of revolutions in accordance with the signal of the weighing instrument 109 installed in the lower reservoir 108 In addition, the rotary extractor (11) through the nitrogen supply conduit (206) to the third ore conduit (203) connecting the sludge powder discharged between the final reduction path (4) and the high temperature molten iron manufacturing apparatus (5) It connects with the pneumatic conduit 24 supplied as nitrogen gas supplied.

In addition, the connection portion of the pneumatic conduit 24 connected to the third ore conduit 203 to supply the sludge powder is formed to be inserted into the third ore conduit 203, as shown in FIG. Is composed of heat-resistant steel, the insertion depth of which is inserted from the side of the third ore conduit 203 to the range of 1/3 to 2/3 of the diameter of the third ore conduit 203, and the insertion angle θ is The outer surface of the three ore conduit 203 is about 45 °, the lower end is preferably formed to be incision so that the sludge powder discharged into the third ore conduit 203 can be immediately introduced into the reducing iron flow.

The operation and effects of the present invention having the configuration as described above will be described.

First, the sludge discharged from the water treatment device 8, which separates the dust contained in by-product gas generated from the molten iron manufacturing facility as process water, has a water content of about 50%, and the sludge is connected to the water treatment device 8. The tube 8a is supplied to the dehydrator 100 connected through the medium to solidify while dehydrating the water content to within 10%.

And, the sludge dehydrated and solidified in the dehydrator 100 is dried so that the water content is lowered to within 1% while continuously passing through the dryer 101, and the solidified and dried sludge is discharged to the crusher 102 side. In the crusher 102, the sludge is crushed into a powder form.

At this time, the sludge to be crushed is considered to be conveyed through the third ore conduit 203 so that the particle size is preferably 1mm or less, for this purpose, the sludge powder crushed in the crusher 102 is a classifier (103) As supplied to the) side, the sludge powder having a particle size of 1mm or less of the sludge powder supplied to the upper side of the classifier 103 is discharged to the lower side, while the sludge powder having a particle size of 1mm or more is the shredder 102 It is recycled to the side and crushed to have an appropriate particle size.

The sludge powder falling down through the classifier 103 is supplied into and stored in the upper storage tank 104 of the lower portion, wherein the upper storage tank is used to prevent ignition of the carbon component contained in the sludge. As the internal storage space of 104, nitrogen gas is supplied through the nitrogen supply conduit 205 to maintain the inside of the inert atmosphere. In addition, the nitrogen gas supplied into the upper reservoir 104 is discharged through an outlet installed on the upper side so as not to pressurize the inside of the upper reservoir 104, and externally through the outlet in the dust collector 105 installed at the outlet. Along with the discharged nitrogen gas, the discharged sludge powder is collected and recovered.

On the other hand, when the sludge powder stored in the lower reservoir 105 in communication with the upper reservoir 104 is a predetermined amount or less, since the sludge powder is not detected in the lower level switch 112 attached thereto, the upper reservoir ( When the shutoff valve 107 installed in the conduit connecting the 104 and the lower reservoir 105 is switched from the closed state to the opened state, the sludge powder in the upper reservoir 104 begins to be charged into the lower reservoir 105. . When the sludge powder charged in the lower reservoir 105 is detected by the upper level switch 112 mounted on the lower reservoir 105, the shutoff valve 107 opened by the detection signal is closed. This stops the sludge powder supply into the lower reservoir 105.

And, while the sludge powder is made or the rotary extractor 110 connected to the lower outlet of the lower reservoir 105, the sludge powder is sufficiently stored and weighing unit 109 for continuously measuring the weight change of the lower reservoir 108 and It is connected to the electrically connected configuration to control the extraction amount, the sludge powder discharged through the rotary extractor 109 is one end is connected to the outlet of the rotary extractor 109, the final reduction path ( 4) is discharged through the pneumatic conduit 24, the other end of which is connected to the third ore conduit 203 connecting between the high temperature annealed iron manufacturing apparatus (5).

At this time, the air supply conduit 24 is connected to the nitrogen supply conduit 206 and the sludge powder supplied as nitrogen gas supplied therefrom is supplied to the third ore conduit 203 and charged into the third. After being mixed with the reduced-reduction iron flow supplied through the ore conduit 203, it is transferred to the high-temperature-hardened iron manufacturing apparatus 5 and hardened together with the reduced-reduction iron.

In this case, when an excessive amount of sludge powder is mixed in the high temperature annealed iron manufacturing apparatus 5, the quality produced in the high temperature annealing agent manufacturing apparatus 5 may be deteriorated by the carbon component contained in the manufactured sludge. In addition, the extraction amount of the sludge powder extracted from the rotary extractor 110 is preferably limited to within 5% of the loading amount of the iron ore to the preheating furnace (2).

Table 2 shows the total reuse of the by-product sludge, and the density, compressive strength, and differentiation degree by the drop test of mixed iron dehydrated, dried and crushed sludge powder by weight ratio of about 5% in the reduced iron The mechanical properties related to the overall hardened iron quality were measured and presented, and they were also presented in preparation for the quality standards of iron hardened iron required for stable operation.

Mechanical Properties of Sludge Mixed Hardened Iron Compared to Quality Standard Density (g / cm3) Compressive Strength (Kg / cm ² ) + 9.5mm particle size fraction (%) after drop test Mixed iron oxide with mixed sludge powder 3.7 to 4.46 480-980 90.8 ~ 96.1 Hardened Iron Quality Standard > 4 > 400 > 90

Table 2 shows that the agglomerated iron manufactured by mixing the sludge powder satisfies the quality standard, which is a by-product generated when the general coal and the iron ore are manufactured by applying the apparatus according to the present invention to the molten iron manufacturing equipment. It shows that the total amount of sludge can be reused in the process itself.

According to the present invention having the above-described configuration, after drying and crushing a part of the by-product sludge in a facility for manufacturing molten iron using ordinary coal and iron ore ore, the final reduction path and the iron hardened iron manufacturing device are connected to each other It is charged into the transported ore conduit and is agglomerated together with the final reduced iron in the agglomerated iron manufacturing apparatus and charged into a molten gasifier, thereby reducing the amount of by-product sludge, thereby reducing the sludge treatment cost, and carbon contained in the sludge. And the iron component can be recycled in the process to reduce the loss of raw materials, while reducing the environmental pollution by the by-product sludge generated during the production of molten iron, while improving the work productivity is obtained.

While the invention has been shown and described with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit or scope of the invention as set forth in the claims below. I would like to clarify that knowledge is easy to know.

Claims (3)

Preheating furnace (2), preliminary reduction furnace (3), final reduction furnace (4) consisting of a preheating furnace (2) in which reduced iron ore flows, the high-temperature annealed iron manufacturing apparatus (5) connected thereto, and melting connected thereto The first and second ore conduits 201 and 202, the final reduction path 4, and the high-temperature annealed iron manufacturing apparatus, each comprising a gasification furnace 1, in which ore and reducing gas flow between the flow reduction paths. (5) a collecting device provided with a third ore conduit 203 connecting therebetween, and installed at the rear of the exhaust gas conduit 204 of the three-stage flow reduction reactor and the exhaust gas conduit 303 for pressure control of the molten gas furnace 1. (6) (7) and a molten iron manufacturing facility for manufacturing molten iron having a water treatment device (8) connected to the collecting device (6) (7), A dehydrator 100 for removing and solidifying water contained in the sludge discharged from the water treatment device 8; A dryer (101) for drying the sludge discharged from the dehydrator (100); A crusher 102 for crushing the dried sludge discharged from the dryer 101 into a powder having a particle size of 1 mm or less; A classifier (103) for classifying the sludge powder crushed by the crusher (102) into a particle size of a predetermined size; The sludge powder discharged from the classifier 103 is stored, and the nitrogen gas is internally supplied through the nitrogen supply conduit 205 to maintain the internal atmosphere in an inactive state, and the dust collector 105 is discharged to the discharge port through which the supplied nitrogen gas is discharged. An upper reservoir 104 mounted thereon; Upper and lower levels of the upper and lower reservoirs 104 are connected to each other via the expansion pipe 106 and the shutoff valve 107 and detect the high and low levels of the sludge powder supplied through the shutoff valve 107. A lower reservoir 108 having switches 111 and 112 and equipped with a weighing instrument 109 for continuously measuring the weight change of the injected sludge powder; A rotary extractor (110) installed at a lower outlet of the lower reservoir (108) to control discharge of sludge powder while adjusting the number of revolutions according to the signal of the weighing unit (109); It characterized in that it comprises a pneumatic conduit 24 for supplying the sludge powder discharged from the rotary extractor 110 as a nitrogen gas supplied through the nitrogen supply conduit 206 to the third ore conduit 203. By-product sludge recycling apparatus in molten iron manufacturing equipment using coal and iron ore. The method of claim 1, The pneumatic conduit 24 is composed of a heat-resistant steel material, the connection portion is inserted into the third ore conduit 203, the insertion depth is 1 of the diameter of the third ore conduit 203 from the side of the third ore conduit 203. Inserted in the range of / 3 to 2/3, the insertion angle (θ) is about 45 ° with respect to the outer surface of the third ore conduit 203, the lower end is discharged into the third ore conduit (203) By-product sludge recycling apparatus for molten iron manufacturing equipment using ordinary coal and iron ore, characterized in that the sludge powder is cut to be immediately introduced into the reducing iron flow. The method of claim 1, The weighing unit 109 preheats the extraction amount of the sludge powder extracted from the rotary extractor 110 so that the quality produced in the high temperature compaction agent manufacturing apparatus 5 is not deteriorated by the carbon component included in the sludge. A by-product sludge recycling apparatus for molten iron manufacturing equipment using ordinary coal and iron ore, characterized in that it controls within 5% of the amount of iron ore charged to the furnace (2).