Search

CN-117720315-B - Preparation process of sulfur-containing tailing baking-free brick

CN117720315BCN 117720315 BCN117720315 BCN 117720315BCN-117720315-B

Abstract

The invention discloses a process for preparing sulfur-containing tailing baking-free bricks, which comprises the steps of (1) mixing ethanol and water to prepare a mixing liquid, and then adding silicate cement powder, gypsum powder and sodium alginate powder into the mixing liquid to form slurry. And coating the slurry on the surface of the sulfur-containing tailing, and then naturally curing to obtain the sulfur-containing tailing aggregate. (2) Uniformly mixing the fly ash, the lithium slag, the sulfur-containing tailing aggregate, the cement, the water reducing agent and water, and then pressing and molding the obtained mixture and curing to obtain the sulfur-containing tailing baking-free brick. The process can effectively improve the chemical stability of the sulfur-containing tailings, and alleviate the problem that the sulfur-containing tailings are easy to cause the deterioration of the mechanical properties of baking-free bricks.

Inventors

  • DING DAN
  • ZHANG ZHIGUO
  • SHAN SHIFENG
  • LUO CHUANHUA
  • CHEN PEIYUAN
  • ZHANG SHIWEN
  • YU MIN
  • ZHENG YONGHONG

Assignees

  • 安徽省地质矿产勘查局321地质队
  • 安徽理工大学

Dates

Publication Date
20260512
Application Date
20231218
Priority Date
20231212

Claims (15)

  1. 1. The preparation process of the sulfur-containing tailing baking-free brick is characterized by comprising the following steps of: (1) Mixing ethanol and water to prepare a mixing solution, and then adding silicate cement powder, gypsum powder and sodium alginate powder into the mixing solution to form slurry, wherein the mixing solution, the silicate cement powder, the gypsum powder and the sodium alginate powder are mixed according to the proportion of 5ml to 0.4-0.55 g to 0.06-0.08 g and 0.1-0.15 g; (2) The method comprises the steps of uniformly mixing 25-35 parts by weight of fly ash, lithium slag, 20-30 parts by weight of sulfur-containing tailing aggregate, 45-60 parts by weight of cement, 10-16 parts by weight of water and 1.8-2.4 parts by weight of 20-27 parts by weight of water, and then compacting and curing the obtained mixture to obtain the sulfur-containing tailing baking-free brick, wherein the mixture also comprises 5-8 parts by weight of repairing agent and 0.7-1.2 parts by weight of curing agent, and the preparation method comprises the following steps: (i) Mixing ethylene-vinyl acetate copolymer rubber powder with absolute ethyl alcohol to prepare coating liquid; (ii) Mixing corncob particles with a saturated aqueous solution of methyl silanol sodium salt, standing, taking out and drying after the corncob particles are adsorbed and saturated; (iii) And (3) coating the surface of the diphenylmethane diisocyanate particles by applying the coating liquid, and then heating and curing to obtain the curing agent.
  2. 2. The process for preparing sulfur-containing tailing baking-free bricks according to claim 1, wherein in the step (1), the mass fraction of ethanol in the mixing liquid is 60-70%.
  3. 3. The process for preparing sulfur-containing tailing baking-free bricks according to claim 1, wherein in the step (1), the ratio of the slurry to the sulfur-containing tailing is 30-35 parts by weight and 92-100 parts by weight.
  4. 4. The process for preparing sulfur-containing tailing baking-free bricks of claim 1, wherein in the step (1), the particle size of the sulfur-containing tailing is 5-10 mm.
  5. 5. The process for preparing sulfur-containing tailing baking-free bricks according to claim 1, wherein in the step (1), the curing time is 2-5 days.
  6. 6. The process for preparing sulfur-containing tailing baking-free bricks of claim 1, wherein in the step (ii), the solid content of the coating liquid is 40-45%.
  7. 7. The process for preparing sulfur-containing tailing baking-free bricks according to claim 1, wherein in the step (ii), the temperature of the heat curing treatment is 50-65 ℃ and the time is 20-30 min.
  8. 8. The process for producing sulfur-containing tailing baking-free bricks of claim 1, wherein in the step (iii), the particle size of the diphenylmethane diisocyanate is 20 to 40 mesh.
  9. 9. The process for preparing sulfur-containing tailing baking-free bricks of claim 1, wherein in the step (iii), the solid content of the coating liquid is 40-45%.
  10. 10. The process for preparing sulfur-containing tailing baking-free bricks according to claim 1, wherein in the step (iii), the temperature of the heat curing treatment is 50-65 ℃ for 15-25 min.
  11. 11. The process for producing a sulfur-containing tailing baking-free brick according to any one of claims 1 to 10, further comprising 2 to 4 parts by weight of fiber yarn in step (2).
  12. 12. The process for preparing sulfur-containing tailing baking-free bricks of claim 11, wherein the fiber filaments comprise at least one of polypropylene fiber, polyacrylonitrile fiber and carbon fiber.
  13. 13. The process for preparing sulfur-containing tailing baking-free bricks of claim 12, wherein the length of the fiber filaments is 10-35 mm.
  14. 14. The process for producing a sulfur-containing tailing baking-free brick according to any one of claims 1 to 7, wherein in the step (2), the water reducing agent comprises any one of a polycarboxylic acid water reducing agent, a sulfamate water reducing agent, and a naphthalene water reducing agent.
  15. 15. The process for preparing sulfur-containing tailing baking-free bricks according to claim 1, wherein the water reducing rate of the water reducer is 20-30%.

Description

Preparation process of sulfur-containing tailing baking-free brick Technical Field The invention relates to the technical field of baking-free brick preparation, in particular to a preparation process of sulfur-containing tailing baking-free bricks. Background The baking-free brick is a novel wall material which is prepared by using industrial waste residues (such as fly ash, coal gangue, tailing slag and the like) as main raw materials, and adopting the modes of pressing and forming by mechanical equipment, then naturally curing or steaming and the like without sintering at high temperature. The baking-free brick has a plurality of advantages as a substitute for the traditional baked brick, for example, the baking-free brick does not need high-temperature sintering, so that the baking-free brick is lower in energy consumption, carbon emission and the like, is more environment-friendly and is lower in manufacturing cost. In addition, the baking-free brick can realize larger-scale recycling of industrial waste residues, and the problems of land resource waste, environmental pollution and the like caused by accumulation of a large amount of industrial waste residues are relieved. Sulfur-containing tailings are waste residues generated in the process of mining metal ores (such as copper ores, gold ores and the like), and because pyrites (the main component is FeS 2) is frequently associated in the metal ores, the obtained tailings also contain high content of FeS 2, namely sulfur-containing tailings. When the waste residue is directly used as the raw material of the baking-free brick, cracks are easily generated in the baking-free brick, and the mechanical property is reduced. The main reason is that FeS 2 in the sulfur-containing tailings is easy to undergo oxidation reaction when encountering water and oxygen, and the formed sulfuric acid can react with the water-hydration product calcium hydroxide in the baking-free bricks to form calcium sulfate. These calcium sulfates further react with the unhydrated cement clinker calcium aluminate in the baking-free brick to form an expansive ettringite. When the ettringite is formed in the baking-free bricks which are cured and formed, expansion stress is easy to generate, cracks are formed in the baking-free bricks when the crack resistance limit of the baking-free bricks is exceeded, the mechanical properties of the baking-free bricks are reduced, and even the baking-free bricks are cracked when the mechanical properties of the baking-free bricks are severe. The characteristics of the sulfur-containing tailings lead to the fact that the sulfur-containing tailings are not suitable to be used as raw materials of baking-free bricks, and are also a key problem affecting the recycling utilization of the sulfur-containing tailings. Disclosure of Invention In view of the above, the invention provides a preparation process of a baking-free brick containing sulfur tailings, which can effectively improve the chemical stability of the sulfur-containing tailings and alleviate the problem that the sulfur-containing tailings are easy to cause the deterioration of the mechanical properties of the baking-free brick. Specifically, the invention discloses the following technical scheme. A preparation process of a sulfur-containing tailing baking-free brick comprises the following steps: (1) Mixing ethanol and water to obtain a mixture, and adding silicate cement powder, gypsum powder and sodium alginate powder to obtain slurry. And coating the slurry on the surface of the sulfur-containing tailing, and then naturally curing to obtain the sulfur-containing tailing aggregate for later use. (2) Uniformly mixing the fly ash, the lithium slag, the sulfur-containing tailing aggregate, the cement, the water reducing agent and water, and then pressing and molding the obtained mixture and curing to obtain the sulfur-containing tailing baking-free brick. Further, in the step (1), the mass fraction of the ethanol in the mixed solution is 60-70%. It contains a certain amount of water to partially hydrate the cement in the slurry coated on the sulfur-containing tailings, so that the slurry is cemented on the sulfur-containing tailings. In the step (1), the ratio of the mixing liquid, the silicate cement powder, the gypsum powder and the sodium alginate powder is 5ml to 0.4-0.55 g to 0.06-0.08 g and 0.1-0.15 g. Further, in the step (1), the ratio of the slurry to the sulfur-containing tailing is 30-35 parts by weight, and 92-100 parts by weight. Optionally, the particle size of the sulfur-containing tailings is 5-10 mm. Further, in the step (1), the curing time is 2-5 days. The slurry coated on the sulfur-containing tailing is hardened and glued to the tailing through curing, so that an active coating layer is formed, hydration reaction can be continuously carried out during subsequent preparation of the baking-free brick, the binding force between the sulfur-containing tailing aggregate and the b