CN-122010441-A - Resource utilization method of sulfuric acid aluminate waste residues

Abstract

The invention relates to the technical field of resource utilization, in particular to a method for recycling aluminum sulfate acid waste residues. The method comprises the steps of mixing alkaline substances with sulfides to prepare an alkaline composite material, and mixing the alkaline composite material with aluminum sulfate acidic waste residues to react to obtain an admixture. According to the method, an alkaline composite material and sulfuric acid aluminate waste residues are mixed and reacted, and water in the waste residues is evaporated by utilizing heat generated by an acid-base neutralization reaction, so that a neutral admixture is obtained. The main components of the admixture are calcium silicate, calcium sulfoaluminate and a small amount of unreacted aluminum, calcium and magnesium oxide, and the admixture has good gelation property, and can not only effectively solidify heavy metal ions, but also improve the later strength of the material when used for preparing concrete or cement products.

Inventors

• QIU YU
• FENG YIBIAO
• LIU GANG
• LIN YOUSHENG
• HUANG BAO
• ZHENG HAOWEN
• YOU LIXIAN
• WU HAO
• ZHENG YAOHUI

Assignees

• 福建省金皇环保科技股份有限公司

Dates

Publication Date

20260512

Application Date

20251230

Claims (10)

1. 1. A method for recycling the sulfuric acid aluminate waste residue is characterized by mixing alkaline substances with sulfides to prepare an alkaline composite material, and mixing the alkaline composite material with the aluminum sulfate acid waste residue to react to obtain an admixture.
2. 2. The method for recycling aluminum sulfate acid waste residues according to claim 1, wherein the alkaline substance comprises alkaline industrial byproducts and alkaline components.
3. 3. The method for recycling aluminum sulfate acid waste residue according to claim 2, wherein the alkaline industrial by-products comprise at least one of papermaking white mud, refined steel slag and carbide slag.
4. 4. The method for recycling aluminum sulfate acid waste residue according to claim 2, wherein the alkaline component comprises at least one of calcium hydroxide and magnesium hydroxide.
5. 5. The method for recycling aluminum sulfate acid waste residues according to claim 2, wherein the alkaline composite material comprises, by weight, 80-90 parts of alkaline industrial byproducts, 5-10 parts of alkaline components and 5-10 parts of sulfides.
6. 6. The method for recycling aluminum sulfate acid waste residues according to claim 1, wherein the sulfide is at least one of sodium sulfide and ammonium sulfide.
7. 7. The method for recycling aluminum sulfate acid waste residues according to claim 1, wherein the pH of the alkaline composite material is 11.5-12.5.
8. 8. The method for recycling aluminum sulfate acid waste residues according to claim 1, wherein the pH of the aluminum sulfate acid waste residues is 2.5-3.
9. 9. The method for recycling aluminum sulfate acid waste residues according to claim 1, wherein the mass ratio of the alkaline composite material to the aluminum sulfate acid waste residues is 1:1.8-2.2.
10. 10. The method for recycling aluminum sulfate acid waste residues according to claim 1, wherein the admixture is used for preparing portland cement or concrete.

Description

Resource utilization method of sulfuric acid aluminate waste residues Technical Field The invention relates to the technical field of resource utilization, in particular to a method for recycling aluminum sulfate acid waste residues. Background The water treatment chemical industry can produce aluminum sulfate acid waste residues with strong acid characteristics in the production process, the waste residues are mainly produced by the reaction of bauxite, sulfuric acid and the like serving as production raw materials, and the components mainly comprise silicate, aluminum oxide, ferric oxide and the like, and part of the waste residues contain heavy metal ions such as lead (Pb), nickel (Ni), chromium (Cr) and the like and acidic substances which are not completely reacted. The waste residue contains a large amount of acidic substances such as sulfuric acid and the like, and possibly carries harmful components such as heavy metals and the like, and if the waste residue is not properly treated, serious harm is caused to the ecological environment. At present, the disposal modes of the sulfuric acid aluminate waste residues mainly comprise a landfill method, a neutralization stabilization method and a solidification method. Direct landfill is the primary disposal mode, and waste residues are transported to a special landfill site for storage. In some cases, the waste residue is simply dehydrated or preliminarily mixed with alkaline materials to reduce acidity, but the chemical properties of the waste residue are not thoroughly changed. This method relies on an impermeable system to prevent contaminant migration, which is a "tip-control" technique. The landfill mode permanently occupies land resources, and needs to continuously maintain an anti-seepage system and percolate treatment facilities, so that economic burden exists for a long time. The neutralization stabilization treatment is to neutralize the waste residue by adding lime, so that the pH value is raised to be neutral or slightly alkaline. In this process, soluble metal ions such as aluminum, iron, etc. form hydroxide precipitates, and part of the heavy metal ions co-precipitate or adsorb to the newly formed solid phase. The neutralized product is usually subjected to filter pressing and dehydration to form stabilized slag, and then landfill or recycling attempt is performed. The neutralization treatment consumes a large amount of lime or industrial alkali, the reaction releases heat severely, the operation environment is bad, and the operation cost is high. Moreover, high-concentration sulfate in the waste residue is difficult to remove by conventional neutralization, and metal hydroxide in the neutralized product can be redissolved and released (such as 'acid return' phenomenon) under the action of environmental pH change or carbonation, so that secondary release of pollutants is caused, and the soil salinization and the water mineralization degree are increased. The solidifying technology is to mix cement, lime or high molecular polymer and other solidifying agent with waste slag to fix pollutant in the solidified matter through physical encapsulation and chemical bonding. The method aims to reduce the permeability of waste residues and the leaching toxicity of pollutants, so that the waste residues can meet the landfill site standard or can be used as low-end building materials such as roadbed materials. Under the long-term weathering, freeze thawing or acid precipitation erosion, the microstructure of the solidified body can be damaged, and heavy metals and high-concentration sulfate are gradually leached out to pollute the underground water and soil. Disclosure of Invention The invention aims to solve the technical problem of providing a method for recycling aluminum sulfate acidic waste residues, which has high stability and is not easy to pollute. In order to solve the technical problems, the technical scheme adopted by the invention is that the method for recycling the aluminum sulfate acidic waste residues is used for mixing alkaline substances and sulfides to prepare an alkaline composite material, and the alkaline composite material and the aluminum sulfate acidic waste residues are mixed and reacted to obtain an admixture. The method for recycling the aluminum sulfate acid waste residue has the beneficial effects that the alkaline composite material and the aluminum sulfate acid waste residue are mixed and reacted, and the heat generated by the acid-base neutralization reaction is utilized to evaporate the water in the waste residue, so that the neutral admixture is obtained. The main components of the admixture are calcium silicate, calcium sulfoaluminate and a small amount of unreacted aluminum, calcium and magnesium oxide, and the admixture has good gelation property, and can not only effectively solidify heavy metal ions, but also improve the later strength of the material when used for preparing concrete or cement products. Detailed De