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CN-117819850-B - Firing method of sulfate slag-based porcelain aggregate with adjustable expansion coefficient

CN117819850BCN 117819850 BCN117819850 BCN 117819850BCN-117819850-B

Abstract

The invention belongs to the technical field of solid waste recycling, and relates to a firing method of a sulfate slag-based porcelain aggregate with adjustable expansion coefficient. Drying sulfuric acid residues, phosphorus mud and polluted soil, performing ball milling to obtain powder, uniformly mixing the powder with an expanding agent to obtain a mixed material, adding water into the mixed material to granulate the mixed material to obtain an aggregate biscuit, heating the aggregate biscuit to 100-120 ℃ for drying, heating the dried aggregate biscuit to 300-600 ℃ for preheating, continuously heating to 1080-1200 ℃ for firing, and quenching the fired sintered balls at room temperature to obtain the composite material. The firing method can realize the adjustment of expansion times and densities of the sulfuric acid slag-based porcelain aggregate through the adjustment in the preparation process, and can realize the utilization of high-value resources of various refractory solid wastes.

Inventors

  • YANG YANFENG
  • TIAN CHAO
  • SHAO YINGYING
  • MA JINWEI

Assignees

  • 山东山科生态环境研究院有限公司

Dates

Publication Date
20260505
Application Date
20231108

Claims (8)

  1. 1. A firing method of a sulfate slag-based porcelain aggregate with adjustable expansion times is characterized by drying sulfate slag, phosphorus mud and polluted soil, performing ball milling to obtain powder, uniformly mixing the powder with an expanding agent to obtain a mixed material, adding water into the mixed material to granulate the mixed material to obtain an aggregate biscuit, heating the aggregate biscuit to 100-120 ℃ to dry, heating the dried aggregate biscuit to 300-600 ℃ to perform preheating treatment, then continuously heating to 1080-1200 ℃ to perform firing treatment, and placing sintered balls after firing treatment in a room temperature condition to perform quenching treatment to obtain the porcelain aggregate; Wherein, the weight portion of the dry weight is calculated to be 40-60 portions of sulfate slag, 10-30 portions of phosphorus mud, 10-50 portions of polluted soil and 0.5-1 portion of expanding agent; The temperature programming rate of the preheating treatment is 5-15 ℃ per minute; or the heat preservation time of the preheating treatment is 10-25 min; The temperature programming rate of the firing treatment is 10-30 ℃ per minute; Or the heat preservation time of the firing treatment is 8-20 min.
  2. 2. The firing method of the expansion-multiple-adjustable sulfate slag-based porcelain aggregate according to claim 1, wherein the sulfate slag, the phosphorus mud and the polluted soil are dried until the moisture content is lower than 0.5% by mass.
  3. 3. The firing method of the sulfate slag-based porcelain aggregate with adjustable expansion coefficient according to claim 1, wherein the particle size of the powder is 80-100 meshes.
  4. 4. The firing method of the sulfate slag-based porcelain aggregate with adjustable expansion coefficient according to claim 1, wherein the ball milling condition is that the rotational speed of a ball mill is set to be 200-250 r/min, the overturning speed is set to be 4-8 times/min, and the ball milling time is 20-40 min.
  5. 5. A sulfate slag-based porcelain aggregate, characterized by being obtained by the firing method according to any one of claims 1 to 4.
  6. 6. The sulfate slag-based porcelain aggregate according to claim 5, wherein the density is 300-700 kg/m 3 and the barrel pressure strength is 4-8 MPa.
  7. 7. The sulfate slag-based porcelain aggregate according to claim 5, wherein the expansion ratio is 0.5 to 7.
  8. 8. Use of the sulfuric acid residue-based ceramized aggregate according to any one of claims 5 to 7 as a building material in a building.

Description

Firing method of sulfate slag-based porcelain aggregate with adjustable expansion coefficient Technical Field The invention belongs to the technical field of solid waste recycling, and relates to a firing method of a sulfate slag-based porcelain aggregate with adjustable expansion coefficient. Background The disclosure of this background section is only intended to increase the understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art already known to those of ordinary skill in the art. The sulfuric acid slag is solid residue obtained after the pyrite is subjected to high-temperature roasting, desulfurization and oxidation in a fluidized bed furnace to prepare acid, 0.8-1.1 t of slag can be produced when 1t of sulfuric acid is produced, and annual yield is huge. The sulfuric acid slag mainly comprises Fe 2O3、Fe3O4、CaSO4 and SiO 2, and contains toxic and harmful elements such as heavy metals copper, lead, zinc, sulfur, arsenic and the like, so that under the condition of long-term storage, a large amount of land is occupied, and the ecological environment can be greatly polluted when entering water and soil. Therefore, a high-value sulfuric acid residue resource utilization technology needs to be developed to meet the requirement of abolished city-free city construction. In the process of preparing the ceramsite and the ceramic material, clay or a binder is required to be added for preparation and molding. The inventor finds that in the process of preparing the porcelain aggregate by utilizing raw materials such as sulfuric acid residues, the difference of chemical components is large due to different reasons such as regions and batches, and expansion times and densities cannot be effectively regulated and controlled in the process of preparing the porcelain aggregate, so that the yield of the sulfuric acid residue porcelain aggregate is difficult to improve, and meanwhile, the utilization of high-value building materials of the sulfuric acid residues is influenced. Disclosure of Invention In order to solve the defects of the prior art, the invention aims to provide the firing method of the sulfate slag-based porcelain aggregate with adjustable expansion coefficient, which not only can realize the adjustment of the expansion coefficient and the density of the sulfate slag-based porcelain aggregate through the adjustment in the preparation process, but also can realize the utilization of various high-value resources of difficult-to-treat solid waste. In order to achieve the above purpose, the technical scheme of the invention is as follows: On the one hand, the firing method of the sulfate slag-based porcelain aggregate with adjustable expansion coefficient comprises the steps of drying sulfate slag, phosphorus mud and polluted soil, performing ball milling to obtain powder, uniformly mixing the powder with an expanding agent to obtain a mixed material, adding water into the mixed material to granulate the mixed material to obtain an aggregate biscuit, heating the aggregate biscuit to 100-120 ℃ to dry, programming the dried aggregate biscuit to 300-600 ℃ to perform preheating treatment, continuing programming to 1080-1200 ℃ to perform firing treatment, and placing sintered balls after the firing treatment under room temperature to perform quenching treatment to obtain the porcelain aggregate; the dry weight of the slag is 40-60 parts of sulfate slag, 10-30 parts of phosphorus mud, 10-50 parts of polluted soil and 0.5-1 part of expanding agent. The expansion mechanism of the porcelain aggregate prepared by the invention is that in the high-temperature firing process, fe2O3, C and other substances in the raw materials react to release gas, and meanwhile, the formed liquid phase wraps the gas, and the honeycomb porous structure is formed after cooling. The content of SiO 2 in the sulfuric acid residue raw material adopted by the invention is 30-42%, and the content of Fe 2O3 is 45-55%. The high content Fe 2O3 reacts with phosphorus mud, polluted soil and C in the added expanding agent to release CO, CO 2 and other gases, and the generated liquid phase is wrapped in the rapid heating stage, so that the aggregate expands. Besides the influence of raw material components, the expansion of the aggregate also has a certain influence on the sintering system of the aggregate, and the possible reactions in the preparation process are as follows (1) - (5): C+O2→CO2 (1) C+CO2→2CO (2) 2Fe2O3+C→4FeO+CO2 (3) 3Fe2O3+CO→2Fe3O4+CO2 (4) Fe3O4+C→3FeO+CO (5) According to the invention, through adjusting the proportion of different raw materials, the adding proportion of the expanding agent, the heating program and the firing temperature, the aggregate generates gases with different volumes under different conditions, thereby realizing the purpose of adjusting and controlling the expansion multiple and the densi