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CN-121972284-A - Coal for blast furnace injection and preparation method thereof

CN121972284ACN 121972284 ACN121972284 ACN 121972284ACN-121972284-A

Abstract

The invention belongs to the field of coal, and particularly discloses coal for blast furnace injection and a preparation method thereof. The invention adopts the method of selecting coal first and then concentrating ore, and finally blending the coal and ore to obtain the coal for blast furnace injection, not only adopts low-rank coal to produce the coal for blast furnace injection, but also improves the content of beneficial minerals of CaO in the coal for blast furnace injection, meets the requirements of the actual blast furnace injection process, obviously reduces the emission of gangue resources, reduces the retreatment cost of the gangue and reduces the environmental pressure.

Inventors

  • WANG ZHENFEI
  • WANG GUANPING
  • GAO FENGLI
  • WANG FENG
  • QIAO JUNQIANG
  • DU HONGMEI
  • WANG JIANYUAN
  • PENG DEJUN
  • WANG MENG

Assignees

  • 国能神东煤炭集团有限责任公司
  • 中国神华能源股份有限公司神东煤炭分公司

Dates

Publication Date
20260505
Application Date
20260121

Claims (10)

  1. 1. The preparation method of the coal for blast furnace injection is characterized by comprising the following steps: S1, separating low-rank coal and a medium through a shallow groove to obtain clean coal and gangue 1; S2, throwing the gangue 1 into a medium removing sieve to remove medium, so as to obtain upper-layer sieve materials, lower-layer sieve materials and lower-layer sieve ore pulp; s3, crushing the upper-layer screen material, and then throwing the crushed upper-layer screen material, the crushed lower-layer screen material and water into a cyclone for separation to obtain gangue 2 and gangue 3; s4, throwing the gangue 2 into a medium removal sieve for medium removal to obtain medium removal oversize materials of the gangue 2 and medium removal undersize materials of the gangue 2; s5, dehydrating the medium-removed oversize material of the gangue 2, and mixing the material with the clean coal to obtain the blast furnace injection coal.
  2. 2. The method for producing coal for blast furnace injection according to claim 1, wherein in step S1, the CaO mass percentage in the low-rank ash component is more than 12%.
  3. 3. The method for producing coal for injection into a blast furnace according to claim 1, wherein in step S1, the low-rank coal comprises at least one of weakly caking coal, non-caking coal, long flame coal, and brown coal.
  4. 4. The method for producing coal for blast furnace injection according to claim 1, wherein the medium removing sieve in step S2 is a double-layer straight line medium removing sieve, wherein the upper layer of the double-layer straight line medium removing sieve has a pore diameter of 2-4mm and the lower layer of the double-layer straight line medium removing sieve has a pore diameter of 0.5-1.5mm.
  5. 5. The method for producing coal for blast furnace injection according to claim 1, wherein in step S3, the cyclone is an aqueous medium cyclone, the aqueous medium cyclone comprises a cylindrical section and a conical section, the cone angle of the conical section is an obtuse angle, and a tangential back flushing port is provided at the junction of the cylindrical section and the conical section.
  6. 6. The method for producing coal for blast furnace injection according to claim 1, wherein in step S3, the crushing equipment comprises a hammer crusher, and the particle size of the crushed upper layer screen material is 25mm or less.
  7. 7. The method for producing coal for blast furnace injection according to claim 1, wherein in step S4, the medium removing sieve is a straight line medium removing sieve, and the diameter of the straight line medium removing sieve is 0.5-1mm.
  8. 8. The method for preparing the blast furnace injection coal according to claim 1, further comprising the step S6 of sequentially mixing and magnetically separating the materials under the medium removal sieves of the gangue 3 and the gangue 2 to obtain concentrate and tailings, wherein the concentrate is used as a medium in shallow groove separation, and the tailings enter a slime water treatment link.
  9. 9. The method for preparing coal for blast furnace injection according to claim 1, wherein in the step S1, the medium comprises a suspension of magnetite powder and water, and the separation density of the shallow tank separation is 1-2kg/L; And/or, in the step S3, the sorting density of the sorting is 2-3kg/L.
  10. 10. A blast furnace coal for injection, characterized in that the blast furnace coal for injection is produced by the method for producing a blast furnace coal for injection according to any one of claims 1 to 9, and the mass percentage of CaO in the blast furnace coal ash component is more than 20%.

Description

Coal for blast furnace injection and preparation method thereof Technical Field The invention belongs to the field of coal, and particularly relates to coal for blast furnace injection and a preparation method thereof. Background The blast furnace coal injection plays an increasingly important role in the steel smelting process. For example, the coal injection of a blast furnace generally comprises the following actions of (1) partially replacing metallurgical coke with pulverized coal, so that the iron-making coke ratio of the blast furnace is reduced, the pig iron cost is reduced, (2) adjusting the furnace condition heat system and stably operating, and (3) gasifying and burning the injected pulverized coal in front of a blast furnace tuyere to reduce the theoretical combustion degree, and simultaneously creating conditions for using high wind and oxygen-enriched blast for the blast furnace. Conventionally, clean coal separated by a low-rank coal power coal preparation plant is used as blast furnace injection coal blending, but in the separation process, useful minerals injected by a blast furnace through Cheng Youyi are lost along with gangue. The calcium element in the raw coal has positive effects on the viscosity improvement of blast furnace injection slag, the air permeability of a material column and the desulfurization capability of the slag, and meanwhile, along with the increase of the calcium oxide amount, the combustion curve has a tendency of moving leftwards, so that the addition of calcium has a certain catalytic effect on the combustion of coal dust. After catalytic combustion, the amount of unburned coal powder in the furnace can be obviously reduced, the theoretical combustion temperature can be improved, and the amount of molten agent in the blast furnace can be saved. Disclosure of Invention Aiming at the problem that useful minerals are lost in the process of producing the coal for blast furnace injection by the conventional coal preparation process in the prior art, the invention provides the coal for blast furnace injection and the preparation method thereof. In order to achieve the above purpose, the method specifically comprises the following technical scheme: in one aspect, the invention provides a method for preparing coal for blast furnace injection, comprising the following steps: S1, separating low-rank coal and a medium through a shallow groove to obtain clean coal and gangue 1; S2, throwing the gangue 1 into a medium removing sieve to remove medium, so as to obtain upper-layer sieve materials, lower-layer sieve materials and lower-layer sieve ore pulp; s3, crushing the upper-layer screen material, and then throwing the crushed upper-layer screen material, the crushed lower-layer screen material and water into a cyclone for separation to obtain gangue 2 and gangue 3; s4, throwing the gangue 2 into a medium removal sieve for medium removal to obtain medium removal oversize materials of the gangue 2 and medium removal undersize materials of the gangue 2; s5, dehydrating the medium-removed oversize material of the gangue 2, and mixing the material with the clean coal to obtain the blast furnace injection coal. In the method, low-rank coal is firstly subjected to shallow groove separation (namely coal preparation) to obtain clean coal and gangue, and the gangue is sequentially subjected to medium removal, crushing, cyclone separation, medium removal again and dehydration to obtain treated gangue materials (ore dressing), and then the treated gangue materials are blended with the clean coal to obtain the coal for blast furnace injection. The clean coal after shallow slot sorting is rich in organic minerals, and then the clean coal rich in organic minerals and the gangue rich in inorganic minerals are blended, so that the quality of original low-rank coal is improved, and especially the CaO content of the low-rank coal is improved, the adaptability of the low-rank coal in blast furnace injection is improved, the product value is improved, the waste rock resource emission is reduced, and a new idea is provided for expanding the application of the power coal. Therefore, the method for preparing the coal for blast furnace injection by firstly dressing coal and then dressing and finally blending the coal and the ore is adopted, the low-rank coal is adopted to produce the coal for blast furnace injection, the content of CaO beneficial minerals in the coal for blast furnace injection is increased, the requirement of the actual blast furnace injection process is met, and the emission of gangue resources is obviously reduced. Preferably, in step S1, the CaO mass percentage in the low-rank coal ash component is greater than 12%, more preferably greater than or equal to 15%, and still more preferably 15-20%. Preferably, in step S1, the low-rank coal includes at least one of weakly caking coal, non-caking coal, long-flame coal, or lignite. GB/T18512-2008 "coal technical Condition for blast fu