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CN-121972151-A - Resource utilization method of coal gasification fine slag

CN121972151ACN 121972151 ACN121972151 ACN 121972151ACN-121972151-A

Abstract

The invention relates to the technical field of utilization of coal-based solid waste resources, and discloses a resource utilization method of coal gasification fine slag. The method comprises the steps of (1) pretreating gasified fine slag, mixing the pretreated gasified fine slag with an acid solution, carrying out ultrasonic cavitation treatment on the obtained mixture, (2) carrying out dispersion stabilization treatment and selective flocculation separation on the material obtained in the step (1) in the presence of a gray water dispersing agent and cationic polyacrylamide, then carrying out gravity sedimentation on the treated material to obtain a carbon-rich material, (3) mixing the carbon-rich material with a boron source, then roasting to obtain a boron modified material, and (4) purifying organic wastewater by using the boron modified material. The method has the characteristics of high carbon-ash separation efficiency, simple process flow and low medicament consumption, and provides a solution with industrialization potential for recycling coal-based solid waste and treating organic wastewater.

Inventors

  • LI RUINING
  • JING YUNHUAN
  • YANG HUIJUN
  • ZHANG QISHENG
  • WEI YONGQING
  • QI ZHILI
  • CAO JING
  • YOU RUI

Assignees

  • 国家能源集团宁夏煤业有限责任公司
  • 国家能源集团宁夏煤业有限责任公司煤炭化学工业技术研究院

Dates

Publication Date
20260505
Application Date
20251216

Claims (10)

  1. 1. The resource utilization method of coal gasification fine slag is characterized by comprising the following steps: (1) Pretreating gasified fine slag, mixing the pretreated gasified fine slag with an acid solution, and carrying out ultrasonic cavitation treatment on the obtained mixture; (2) Carrying out dispersion stabilization treatment and selective flocculation separation on the material obtained in the step (1) in the presence of a gray water dispersing agent and cationic polyacrylamide, and then carrying out gravity sedimentation on the treated material to obtain a carbon-rich material; (3) Mixing the carbon-rich material with a boron source, and roasting to obtain a boron modified material; (4) And purifying the organic wastewater by using the boron modified material.
  2. 2. The method according to claim 1, wherein in step (1), the solid-to-liquid ratio of the pretreated gasified slag to the acid solution is 1g:1-10mL; preferably, the acid in the acid solution is at least one of hydrochloric acid, sulfuric acid and nitric acid; preferably, the concentration of the acid solution is 6-20wt%.
  3. 3. The method according to claim 1 or 2, wherein in the step (1), the ultrasonic cavitation treatment conditions include a power of 300 to 500W for 5 to 30min.
  4. 4. The method according to claim 1, wherein in the step (2), the specific process of dispersion stabilization treatment and selective flocculation separation of the material obtained in the step (1) comprises the steps of carrying out first mixed contact on the material obtained in the step (1) and the grey water dispersing agent, and then carrying out second mixed contact on the material and the cationic polyacrylamide; Preferably, the conditions of the first mixing contact comprise a stirring speed of 300-600rpm for 5-30min; preferably, the conditions of the second mixing contact include a stirring speed of 300-600rpm for 5-30min.
  5. 5. The method according to claim 1 or 4, wherein the solid to liquid ratio of the pretreated gasified fine slag to the grey water dispersant is 1t:100-500L; Preferably, the grey water dispersant is selected from at least one of acrylic acid-maleic acid copolymer, polycarboxylic acid and beta-cyclodextrin polymer.
  6. 6. The method according to claim 1 or 4, wherein the mass ratio of the pretreated gasified fine slag to the cationic polyacrylamide is 1t:50-150g; preferably, the molecular weight of the cationic polyacrylamide is 800-1200 ten thousand; Preferably, the cationic polyacrylamide is used in the form of a cationic polyacrylamide solution, and the concentration of the cationic polyacrylamide solution is 0.2-1 wt%.
  7. 7. The method of claim 1, wherein in step (3), the mass ratio of the carbon-rich material to the boron source is 100:5-30; preferably, the boron source is selected from at least one of boric acid, boron oxide and borax.
  8. 8. The method according to claim 1 or 7, wherein in the step (3), the condition of the calcination includes a temperature rise rate of 1 to 10 ℃ per minute, a temperature of 500 to 850 ℃ and a time of 2 to 5 hours.
  9. 9. The method according to claim 1, wherein in the step (4), the purification treatment comprises mixing the boron modified material with the organic wastewater and performing adsorption pretreatment for 10-60min, and then adding persulfate to the system for 1-5h; Preferably, the solid-to-liquid ratio of the boron modified material to the organic wastewater is 0.05-0.3g:1L; Preferably, the ratio of the amount of persulfate material to the volume of the organic wastewater is 1-12mmol:1L.
  10. 10. The method of claim 9, wherein the mass ratio of the boron modified material to the persulfate is 1:3-10; Preferably, the persulfate is selected from at least one of sodium persulfate, potassium persulfate, and ammonium persulfate.

Description

Resource utilization method of coal gasification fine slag Technical Field The invention relates to the technical field of utilization of coal-based solid waste resources, in particular to a resource utilization method of coal gasification fine slag. Background The gasification technology is used as a core technology of modern coal chemical industry, and a large amount of solid waste, namely coal gasification slag, is generated in the production process. The formation mechanism is that coal water slurry or powdered coal reacts with oxygen and steam in an entrained flow gasifier at high temperature to generate synthetic gas, and molten slag generated in the reaction process is cooled and is definitely divided into two parts, namely coarse slag directly discharged from the bottom of the gasifier, fine slag which is discharged along with the synthetic gas and is captured by a subsequent working section, namely gasified fine slag. The production of gasified fine slag is about 40% -60% of the total amount of gas slag, the fine slag enters a black water treatment system after being washed in a multistage circulation mode to form fine slag slurry, and the fine slag slurry is subjected to flocculation sedimentation and vacuum filtration dehydration treatment to finally obtain a filter cake-shaped material with the water content of 50% -60%. According to statistics, the production amount of coal gasification fine slag per year in China exceeds 8000 ten thousand tons, wherein the content of carbon residue is stabilized between 20% and 35%. From microstructure analysis, porous carbon residue in gasified fine slag and aluminosilicate glass body form a complex 'melting-embedding' structure in the high-temperature melting process, namely ash components are filled or adhered into carbonaceous pores. This tight binding characteristic directly results in a substantial reduction in separation efficiency of conventional physical separation methods. In addition, the gasified fine slag has the characteristics of high water content, high ash content, fine particle size, complex components and the like, and the large-scale resource utilization of the gasified fine slag faces serious challenges. At present, the treatment of gasified fine slag in China is mainly mixed with building materials or directly buried, the resource value of the gasified fine slag cannot be fully mined, and the maximum utilization of resources cannot be realized. Based on the above, there is a need to develop a coal gasification fine slag carbon-ash separation technology with high carbon-ash separation efficiency, simple process flow and low medicament consumption, so as to realize efficient recycling of coal gasification fine slag. Disclosure of Invention The invention aims to solve the problem that porous carbon residues and ash components of coal gasification fine slag are difficult to efficiently dissociate and separate in the prior art, so that the coal gasification fine slag cannot realize the maximum utilization of resources, and provides a resource utilization method of the coal gasification fine slag. The method has the characteristics of high carbon-ash separation efficiency, simple process flow and low medicament consumption, realizes the short-flow conversion of gasified fine slag from solid waste to high-efficiency catalyst through multi-process collaborative optimization, and provides a solution with industrialization potential for recycling coal-based solid waste and treating organic wastewater. In order to achieve the above purpose, the invention provides a resource utilization method of coal gasification fine slag, which comprises the following steps: (1) Pretreating gasified fine slag, mixing the pretreated gasified fine slag with an acid solution, and carrying out ultrasonic cavitation treatment on the obtained mixture; (2) Carrying out dispersion stabilization treatment and selective flocculation separation on the material obtained in the step (1) in the presence of a gray water dispersing agent and cationic polyacrylamide, and then carrying out gravity sedimentation on the treated material to obtain a carbon-rich material; (3) Mixing the carbon-rich material with a boron source, and roasting to obtain a boron modified material; (4) And purifying the organic wastewater by using the boron modified material. Preferably, in the step (1), the solid-to-liquid ratio of the pretreated gasified fine slag to the acid solution is 1g:1-10mL. Preferably, the acid in the acid solution is at least one of hydrochloric acid, sulfuric acid and nitric acid. Preferably, the concentration of the acid solution is 6-20wt%. Preferably, in the step (1), the ultrasonic cavitation treatment condition comprises power of 300-500W and time of 5-30min. Preferably, in the step (2), the specific process of carrying out dispersion stabilization treatment and selective flocculation separation on the material obtained in the step (1) comprises the steps of carrying out fi