Method for recovering alkali, selenium and arsenic in arsenic-alkali residue from antimony smelting

Abstract

The invention discloses a method for recovering alkali, selenium and arsenic in arsenic-alkali residue from antimony smelting, comprising the following steps: (1) immersing arsenic-alkali residue in water, filtering and washing to obtain antimony slag and an arsenic-alkali solution; (2) concentrating the arsenic-alkali solution until concentration of arsenic is 12-17 g / L, introducing CO2 to obtainsodium hydrogen carbonate and primary crystallization mother liquor, concentrating the primary crystallization mother liquor until concentration of arsenic is 48-60 g / L, and introducing CO2 to obtainsodium hydrogen carbonate and secondary crystallization mother liquor; (3) using acid to regulate pH of the secondary crystallization mother liquor to 1-4, heating and reacting to obtain black selenium and a selenium-removed solution; and (4) carrying out SO2 reduction on the selenium-removed solution, conducting evaporation and concentration, cooling for crystallization and filtering to obtain arsenic trioxide and an arsenic-removed solution. By the above method, efficient recovery of alkali, selenium and arsenic in arsenic-alkali residue is realized, and effective enrichment of antimony isalso realized, oxidation for deep antimony removal is not required, arsenic-alkali separation is thorough, no sodium arsenate composite salt is generated, and acid consumption and use amount of a reducing agent are low. In addition, the process is concise, and the method has good economic and environmental benefits.

Description

technical field [0001] The invention relates to a method for disposing of arsenic-alkali slag from antimony smelting, in particular to a method for recovering alkali, selenium and arsenic from the arsenic-alkali slag, and belongs to the technical field of comprehensive recycling of metallurgical solid waste. Background technique [0002] my country's antimony resource reserves and output both rank first in the world, mainly concentrated in the Lengshuijiang tin mine area of ​​Hunan Province. The antimony ore reserves in this area account for more than 60% of the world's total reserves, and the output of antimony products accounts for 80% of the world's total output. At present, 95% of my country's antimony smelting production adopts pyrometallurgical smelting process. In the crude antimony refining process, soda ash is usually added to remove arsenic to obtain refined antimony, and at the same time, solid waste residue containing arsenic will be produced, that is, arsenic-alk...

AI Technical Summary

Problems solved by technology

For example, the sodium arsenate compound salt method is to recover the antimony in the arsenic-alkali slag by water leaching, concentrate and evaporate the leachate to dryness, and dry the physical water to obtain the sodium arsenate compound salt. This compound salt is still a hazardous solid waste, although it can be used as glass Clarifying agent, but the product components are unstable, which is easy to affect the quality of the glass. Now the environmental protection requirements are stricter, and its use is strictly restricted. At the same time, the sodium arsenate compound salt contains valuable components that can be recycled, and relevant recovery of components

CN 200410013369.2 discloses a method for separating and recovering sodium arsenate and alkali by fractional crystallization. The method uses the difference in solubility between sodium arsenate and sodium carbonate at high temperature to realize the separation and recovery of arsenic and alkali. The one-step crystallization product is mainly sodium arsenate At the same time, it also contains a small amount of alkali, and the second-step crystallization product is crude alkali, which is returned to the antimony smelting crude antimony refining dearsenic process, but the crude alkali contains 2.29% arsenic, which will cause a vicious circle of arsenic in the smelting system

CN200410023055.0 discloses a pollution-free arsenic-alkali slag treatment technology, which utilizes CO 2 Dealkalization, the carbonate after washing is returned to antimony smelting, and the aqueous solution system is circulated, but the arsenic content in the carbonate is high, and the arsenic content is still about 1% after washing. In addition, hydrogen sulfide will be produced during the dearsenization of sodium sulfide. The environment is relatively poor, and the sodium sulfate in the dearsenic solution is subsequently treated with barium hydroxide, and the treatment cost is relatively high

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