CN212451496U - Pretreatment device for light steel scrap - Google Patents

Abstract

The utility model discloses a preprocessing device of light-duty steel scrap belongs to the iron and steel field of smelting, broken system, steel scrap heating dezincification system, steel scrap hot pressing piece system, hot pressing piece heat transfer system that link to each other including the order. Compared with the prior art, the light scrap steel can be pressed into the steel plate with the density as high as 6.0t/m³The recovery rate of the heavy scrap steel can be improved by 4.4% in the steelmaking process; 92 percent of zinc in the scrap steel is removed, and the harm of the zinc to the blast furnace production of the iron and steel enterprises is greatly reduced.

Description

Pretreatment device for light steel scrap

Technical Field

The utility model belongs to the technical field of the steelmaking raw materials prepares, concretely relates to broken, the steel scrap heating dezincification of steel scrap, steel scrap hot pressing piece, high temperature steel scrap hot conveying system.

Background

The steel scrap is a main raw material produced by an electric arc furnace for steelmaking and is also an important raw material produced by the converter, the steel scrap is divided into different types such as heavy waste, medium waste, light thin material and the like according to the thickness, the size, the specific gravity and the like, and the light steel scrap such as the light waste, the light thin material and the like can seriously influence the steelmaking production rhythm due to irregular size and small bulk density during steelmaking production, so that the yield is reduced, the cost is increased, and the consumption of steel and iron materials is increased.

The galvanized materials account for a large proportion in light scrap steel, most of zinc in the galvanized materials can be brought out along with steelmaking dust removal ash in the steelmaking process, so that the zinc content in the steelmaking dust removal ash is increased, the zinc content of primary dust removal ash can reach 0.5-1%, the ash amount generated by each ton of steel can reach about 30kg, the zinc content of secondary dust removal ash and tertiary dust removal ash can reach 1-5%, the production amount of each ton of steel is about 1kg, the cost of the low-zinc dust removal ash for the zinc extraction process is too high and cannot be accepted by nonferrous metal smelting factories, and the steelmaking dust removal ash contains more than 50% of iron, so the steelmaking dust removal ash is mainly applied to producing sintered ores and being used for blast furnace ironmaking at present, but the harm of zinc to blast furnace smelting is extremely serious, the zinc absorbs heat in a high-temperature region and is reduced and evaporated in the high-temperature region, and is oxidized and evaporated in the low-temperature region, After being condensed, the condensed slag adheres to the furnace burden to move up and down and circulate continuously, the enrichment in the blast furnace is up to 80 times, the precious heat of a high-temperature area is wasted greatly, the fuel ratio of the blast furnace is increased greatly, the yield is reduced greatly, malignant accidents such as malignant tumors, material collapse, furnace coolness and the like can be caused seriously, and the yield, the quality and the cost of the blast furnace are seriously influenced. Therefore, the requirement of the iron-making industry on the zinc load of the blast furnace is very strict, 1000m³The zinc content of the sintering ore entering the furnace is required to be not more than 0.01% by the blast furnace above grade, and practice proves that under the condition that about 100kg of light scrap steel is added to each ton of steel of the converter, after the fly ash is used for sintering production with matched productivity, the zinc content of the sintering ore can reach more than 0.03%, exceeds the iron-making requirement by more than 3 times, the influence on the fuel ratio of the blast furnace can reach more than 20kg/t, and the influence on the iron-making yield can reach more than 10%.

The main current methods for treating light scrap are cold briquetting and crushing, which only increase the bulk density properly but do not change the performance substantially, the recovery rate of iron is less than 90%, and the problem of zinc is still unsolved.

At present, the method for treating zinc in scrap steel in the steel industry is to carry out secondary treatment on generated steelmaking fly ash after scrap steel is used in steelmaking, the application is not wide, more than all, the method is to apply the steelmaking primary fly ash to sintering and ironmaking, enrich zinc in blast furnace cloth bag fly ash and then carry out treatment, the main treatment methods include a rotary hearth furnace method, a rotary kiln method, and a method of centralized treatment by using a small-sized sintering machine and a small-sized blast furnace, but the method has the following problems:

1) the production amount of the steelmaking primary dedusting ash is large, the quantity of the steelmaking primary dedusting ash is three times of the total amount of the steelmaking secondary dedusting ash, the steelmaking tertiary dedusting ash and the blast furnace cloth bag dedusting ash, the zinc amount is only about 0.7%, and the recovery rate of zinc is only 50%, so more enterprises can only select to apply to sintering and iron making, and after the zinc is enriched in the blast furnace cloth bag dedusting ash, the zinc is recovered, and thus, the blast furnace production is influenced certainly.

2) The process for treating the fly ash by adopting the methods of a rotary hearth furnace, a rotary kiln and the like has the advantages that the zinc content in the treated product still reaches about 0.4 percent, so the lower the zinc content in the fly ash is, the lower the recovery rate is, the average zinc content of the two-time and three-time fly ash for steelmaking and the average zinc content of the fly ash for bag dedusting of a blast furnace are only about 2 percent under the normal condition, the recovery rate of zinc is only about 80 percent, and the rest zinc still needs to return to the steelmaking or the blast furnace for continuous circulation.

3) The process for treating the dust-removing ash by using the special agglomeration machine and the small-sized smelting furnace has the advantages that zinc does not enter a normal steel production procedure in theory, the recovery rate is highest, but when the process is used for smelting a high-zinc raw material, the fuel consumption is more than 1.5 times of that of the common iron-making production, and a large amount of energy is wasted.

In summary, the current treatment technologies do not collect zinc in the scrap from the source, so that either one-time damage to blast furnace production is caused or a large amount of energy is wasted, and thus, the current treatment technologies are not widely popularized. How to do from the source can not only effectively recover the zinc in the scrap steel, directly avoid the harm to iron-making production, but also improve the production efficiency of steelmaking, increase the usage amount and yield of light scrap steel, reduce energy consumption, and can be popularized more widely, which is the main problem existing in the prior art.

SUMMERY OF THE UTILITY MODEL

The technical task of the utility model is to provide a preprocessing device of light-duty steel scrap to the not enough of above prior art. The method is a circular economy technology which simultaneously has the advantages of improving the efficiency, reducing the energy consumption, recovering wastes, treating the symptoms and the root causes, removing most of zinc elements in the scrap steel through high temperature, avoiding the influence on blast furnace smelting in the application process, greatly improving the use value of the light scrap steel, effectively extracting the zinc in the scrap steel for refining metal zinc, and finally loading a high-temperature scrap steel hot-pressing block into a steelmaking furnace through a hot-conveying system, thereby reducing the waste of energy sources, improving the adding amount and smelting rhythm of the converter scrap steel, reducing the energy consumption, recovering wastes, and treating the symptoms and the root causes

The technical proposal of the utility model for solving the technical problem is that: the utility model provides a preprocessing device of light-duty steel scrap which characterized in that: comprises a scrap steel crushing system, a scrap steel heating dezincification system, a scrap steel hot-pressing block system and a hot-pressing block hot-conveying system which are sequentially connected; the scrap steel crushing system comprises a scrap steel crusher and a belt conveyor which are sequentially connected; the waste steel heating and dezincification system comprises a waste steel crushing bin, an electronic belt scale, a charging belt conveyor, a rotary kiln, a combustion-supporting fan, a gas burner, a bag-type dust remover and a dust-removing fan; the scrap steel crushing bin is connected to the tail part of the rotary kiln through an electronic belt scale and a charging belt conveyor; the head of the rotary kiln is provided with a gas burner connected with a combustion fan; the tail part of the rotary kiln is provided with a bag-type dust collector connected with a dust collection fan; the scrap steel hot-pressing system comprises a distributor and a hydraulic machine which are sequentially connected, wherein the hydraulic machine is connected with a hydraulic station; the hot-pressing block hot-conveying system comprises a conveyor, a hot-pressing block storage bin, a crane and a heat-preservation transport vehicle.

In the optimization scheme, the device further comprises a steel shot bin, an iron scrap bin, a steel shot electronic belt scale and an iron scrap electronic belt scale.

In the hot-pressing block hot-conveying system, the conveyor is a plate conveyor, and the crane is an electromagnetic chuck crane.

The conveyor and the hot-pressing block storage bin are provided with heat-insulating covers.

The carriage of the heat-insulation transport vehicle is insulated by adopting a light refractory heat-insulation material, and is provided with a heat-insulation cover.

Compared with the prior art, the utility model discloses following outstanding beneficial effect has:

1. pressing light scrap steel into the steel plate with the density as high as 6.0t/m³The recovery rate of the heavy scrap steel can be improved by 4.4% in the steelmaking process;

2. 92 percent of zinc in the scrap steel is removed, so that the harm of the zinc to the blast furnace production of the iron and steel enterprises is greatly reduced;

3. the zinc content in the collected dust reaches 48 percent, so that the method becomes a raw material for efficiently refining the metal zinc, and because the zinc content is very high, the refining difficulty and cost are greatly reduced, and the recovery rate of zinc is improved.

4. The heat preservation and heat delivery technology of the hot-pressing blocks is adopted, so that the heat of the hot-pressing blocks is effectively utilized, the consumption of molten iron of 11kg/t is reduced, and the steelmaking capacity is improved.

Drawings

Fig. 1 is a process flow diagram of the present invention.

Detailed Description

The invention is further described with reference to the drawings and the detailed description.

Referring to fig. 1, the utility model provides a light-duty steel scrap's preliminary treatment system, it includes broken system 100 of steel scrap, steel scrap heating dezincification system 200, steel scrap hot briquetting system 300, hot briquetting hot conveying system 400 that the order links to each other.

The scrap crushing system 100 includes a scrap crusher 12 and a belt conveyor 13 connected in series. Light scrap in a scrap yard 11 is loaded into a hopper of a scrap crusher 12 by a loader, an electromagnetic chuck, or the like, the scrap crusher 12 is operated to crush scrap into a crushed piece of 200mm or less, and the crushed piece is conveyed to a scrap crushing bin 21 of the scrap heating dezincification system 200 by a belt conveyor 13. The scrap steel is crushed into small-particle-size crushed materials of 0mm to 200mm, so that the heating efficiency and the hot pressing efficiency are improved.

The waste steel heating and dezincification system 200 comprises a waste steel crushing bin 21, an electronic belt scale 22, a charging belt conveyor 23, a rotary kiln 24, a combustion fan 25, a gas burner 26, a bag-type dust remover 27 and a dust removing fan 28. The scrap steel crushing bin 21 is connected to the tail part of the rotary kiln 24 through an electronic belt scale 22 and a charging belt conveyor 23. The head of the rotary kiln 24 is provided with a gas burner 26 connected with a combustion fan 25. The tail of the rotary kiln 24 is provided with a bag-type dust collector 27 connected with a dust collection fan 28.

For steel particles and iron filings to be added, the system also comprises a steel particle bin 21 ', an iron filings bin 21', a steel particle electronic belt scale 22 'and an iron filings electronic belt scale 22'. The materials such as broken scrap steel, steel particles, scrap iron and the like are prepared according to a certain proportion and feeding quantity by using a corresponding electronic belt scale, and the proportion of the broken materials is between 20% and 100% according to the actual production condition.

The prepared materials are loaded into the tail part of a rotary kiln 24 by a loading belt conveyor 23, a combustion fan 25 and a gas burner 26 are used at the head part of the rotary kiln 24 to burn gas or natural gas, the materials in the kiln are heated to about 900 ℃, the temperature of the materials is gradually reduced along with the flow of flue gas to the tail part of the rotary kiln 24 until the temperature is within 200 ℃, and the specific combustion temperature and the gas flow can be adjusted by combining the characteristics of waste steel and the zinc content in dust (the temperature is shown in an embodiment parameter table). Along with the rotation of the rotary kiln 24, the scrap steel moves from the tail part to the head part in the kiln, the temperature is gradually increased, when the temperature reaches above 900 ℃, metal zinc in the scrap steel is completely evaporated into zinc steam, and the zinc steam flows to the tail part of the kiln along with smoke and is finally collected by a bag-type dust collector 27. The movement time of the scrap steel in the rotary kiln is controlled to be 30-60 minutes, and the specific time needs to be adjusted by adjusting the charging speed and the rotary kiln running speed in combination with the characteristics of the scrap steel and the dezincification effect.

The bag-type dust collector 27 is mounted on a smoke hood at the tail of the rotary kiln 24 through a flue, and after zinc-containing dust is pumped into the bag-type dust collector 27 by using the dust removing fan 28 and collected, the smoke reaching the standard is discharged into the atmosphere. After the bag-type dust collector 27 is used for recycling, the zinc content in the produced zinc ash reaches more than 40%, and the zinc-containing dust is used as a raw material of a non-ferrous metal smelting factory and is used for refining metal zinc, so that the metal zinc is effectively recycled.

After zinc in the light scrap steel is extracted, the zinc content in the steelmaking fly ash can be greatly reduced during steelmaking production, so that the steelmaking fly ash is more effectively applied to sintering production in a large quantity, the problems of blast furnace wall nodulation, unsmooth furnace condition, high blast furnace fuel ratio and the like caused by zinc enrichment are avoided, and meanwhile, the zinc content in the blast furnace fly ash can be effectively controlled, so that the blast furnace cloth bag fly ash can be recycled for sintering, and the consumption of sintering solid fuel can be reduced due to a large amount of carbon contained in the blast furnace fly ash.

The scrap steel hot-pressing system 300 comprises a distributor 31 and a hydraulic machine 32 which are connected in sequence, wherein the hydraulic machine 32 is connected with a hydraulic station 33. The high-temperature steel scrap discharged from the tail of the rotary kiln 24 is loaded into a cylinder of a hydraulic press 32 after passing through a distributor 31, and then a hydraulic station 33 is operated to press the high-temperature steel scrap into blocks, wherein the bulk density reaches 6.0t/m under the pressure of more than 100MPa³The method is beneficial to charging and smelting of the steel-making converter or the electric arc furnace, improves the steel-making rhythm and the iron recovery rate, and reduces the charging difficulty of the converter.

The hot-pressing block hot-conveying system 400 comprises a plate conveyor 41, a hot-pressing block storage bin 42, an electromagnetic chuck crane 43 and a special heat-insulating transport vehicle 44. The scrap steel briquettes pressed by the hydraulic press 32 are conveyed 41 by a plate conveyor to a hot briquette storage bin 42, and then loaded into a special heat-insulating transport vehicle 44 by an electromagnetic chuck crane 43 and sent to a steel-making workshop. In order to reduce heat loss and achieve better heat transfer effect, the plate conveyor 41 and the hot-pressed block storage bin 42 must be insulated by heat-insulating covers, and the carriage of the heat-insulating transport vehicle 44 is insulated by adopting a light refractory heat-insulating material and is provided with a heat-insulating cover to ensure that the temperature of the hot-pressed block entering the converter workshop is not lower than 300 ℃. The temperature of the hot-pressed scrap steel can reach more than 600 ℃, and the scrap steel is conveyed to a steelmaking workshop by a special vehicle with heat preservation measures and directly enters a furnace, so that the waste of heat can be avoided.

For better verification, implement on certain scrap steel hot pressing production line in north of Hehe the utility model discloses the technique to apply hot pressing piece in certain iron and steel enterprise 60t converter, examined and tracked each item index and parameter, parameter and result data as follows.

(1) Production scheme

(2) Production index

(3) Effect of steel-smelting application

Use the utility model discloses the briquetting of technical production, per ton steel use 50kg to replace light thin material, and all the other steel scraps still use medium-sized steel scrap, produce Q235 type steel billet, the contrast of steelmaking index is as follows:

note: the iron yield of the light thin material is obtained according to experience, and the calculation method of the iron yield of the light thin material and various hot-pressing blocks comprises the following steps: (iron content of iron blank-iron content of molten iron per ton of steel X iron content of molten iron X iron yield of molten iron-consumption of other scrap steel per ton of steel X iron yield of scrap steel)/consumption of light sheet or hot briquette X iron content. Wherein the iron content of the steel billet is 99 percent, the iron content of the molten iron is 94 percent, the iron yield is 98 percent, and the iron content of other scrap steel is 98 percent, and the iron yield is 98 percent.

(4) Comprehensive analysis

Use the utility model discloses the technique, when all using light-duty steel scrap, the zinc content that the rate of recovery of zinc reaches 92%, in the dust removal ash reaches 48%, when being applied to steelmaking production, the yield of iron has risen 4.4% than the direct light thin material that uses, simultaneously owing to adopt the hot-charging measure for the heat of hot pressing piece has obtained effective utilization, and then has reduced 11kg/t molten iron consumption, has improved the steelmaking productivity.

Use the utility model discloses the technique is joining in marriage and is adding partial steel shot, iron fillings after, each item index has the decline trend, nevertheless joins in marriage and still can obtain better index relatively under the circumstances that the volume of adding does not exceed 50%, in order to reach better index, does not suggest joining in marriage steel shot, iron fillings, unless zinc-containing steel scrap resource is not enough the time can suitably consider.

It should be noted that while the invention has been described in detail with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various obvious changes can be made therein without departing from the spirit and scope of the invention.

Claims (5)

1. The utility model provides a preprocessing device of light-duty steel scrap which characterized in that: comprises a scrap steel crushing system, a scrap steel heating dezincification system, a scrap steel hot-pressing system and a hot-pressing block hot-conveying system which are sequentially connected; the scrap steel crushing system comprises a scrap steel crusher and a belt conveyor which are sequentially connected; the waste steel heating dezincification system comprises a waste steel crushing bin, an electronic belt scale, a charging belt conveyor, a rotary kiln, a combustion-supporting fan, a gas burner, a bag-type dust remover and a dust-removing fan; the scrap steel crushing bin is connected to the tail part of the rotary kiln through an electronic belt scale and a charging belt conveyor; the head of the rotary kiln is provided with a gas burner connected with a combustion fan; the tail part of the rotary kiln is provided with a bag-type dust collector connected with a dust collection fan; the scrap steel hot-pressing system comprises a distributor and a hydraulic machine which are sequentially connected, wherein the hydraulic machine is connected with a hydraulic station; the hot-pressing block hot-conveying system comprises a conveyor, a hot-pressing block storage bin, a crane and a heat-preservation transport vehicle.

2. The pretreatment device of light scrap steel according to claim 1, characterized in that: the iron scrap conveyor also comprises a steel shot bin, an iron scrap bin, a steel shot electronic belt scale and an iron scrap electronic belt scale.

3. The pretreatment device of light scrap steel according to claim 1, characterized in that: in the hot-press block hot-conveying system, the conveyor is a plate conveyor, and the crane is an electromagnetic chuck crane.

4. The pretreatment device of light scrap steel according to claim 1, characterized in that: the conveyor and the hot-pressing block storage bin are provided with heat-insulating covers.

5. The pretreatment device of light scrap steel according to claim 1, characterized in that: the carriage of the heat-insulation transport vehicle is insulated by adopting a light fireproof heat-insulation material, and is provided with a heat-insulation cover.

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