Method for resource utilization of arsenic alkali slag by extraction and separation

Abstract

The invention relates to a method for resource utilization of arsenic alkali slag by extraction and separation. The method comprises the following steps: adding glycerin into arsenic alkali slag subjected to crushing and grinding or placing slurry obtained through grinding of the arsenic alkali slag and the glycerin in a leaching tank for leaching and extraction, and performing solid-liquid separation to obtain antimony-enriched slag and a glycerin phase solution, wherein the obtained glycerin phase solution is a mixed solution containing arsenate and soda ash, the glycerin phase solution is subjected to cooling crystallization or freezing crystallization separation to obtain a mixture of arsenate crystals and soda ash crystals, and glycerin separated through cooling crystallization or freezing crystallization separation is recycled for the leaching and extraction of the arsenic alkali slag; the obtained antimony-enriched slag is a solid mixture containing antimonate and aluminosilicate minerals, and is used for returning antimony to refine or process antimony or antimony oxide and antimonate. The method has the advantages that the flow is short, the investment is relatively low, no waste water pollutants are generated in a separation process, the arsenic alkali slag is extracted and separated by a safe solvent, and the solvent can be recycled.

Description

technical field [0001] The invention relates to a method for resource utilization of arsenic-alkali slag, in particular to a method for extracting and separating arsenic-alkali slag for resource utilization. Background technique [0002] Arsenic-alkali slag is a kind of smelting waste slag mainly containing sodium arsenate, sodium antimonate and sodium carbonate produced during the antimony refining and arsenic removal process of antimony by fire method. Because sodium arsenate is highly toxic and easily soluble in water, it is extremely It is easy to cause environmental pollution incidents, and the solid hazardous waste that has been difficult to properly handle has restricted the healthy development of the antimony smelting industry to a certain extent. [0003] For the arsenic-alkali slag that is difficult to properly handle, scientific and technological workers at home and abroad have continuously carried out a large amount of research and practice. The various technical...

AI Technical Summary

Problems solved by technology

[0018] The above-mentioned fire treatment method requires harsh conditions for thermal reduction treatment, requiring a closed vacuum electric arc furnace, vacuuming with a vacuum pump, and forced vacuuming under high temperature conditions for 1 to 8 hours. The control requirements for this intermittent fire reduction treatment are very strict. , has high requirements for equipment and operation control, and may only be suitable for laboratory or small-batch metallurgical treatment, and the adaptability of large-scale industrial production is doubtful; it is also not suitable for processing arsenic-alkali slag containing a large amount of antimony, which uses a vacuum pump to continuously Under the condition of strong vacuuming at ≥800°C, the volatilization of antimony vapor will occur simultaneously with the sublimation of arsenic (arsenic sublimates at 615°C), and often only arsenic-antimony alloys are obtained; and it is difficult to deal with arsenic acid containing antimonate in large quantities Salt, using carbon as a reducing agent to smelt arsenic-alkali slag, the overall reducing ability is still extremely weak when the reducing temperature is lower than 800°C, and the reducing ability will be better when the temperature is above 900°C, and the higher the treatment temperature for hazardous waste, the less It’s just a problem of high energy consumption and higher equipment requirements, and the potential risk of accidents is even greater, and because the closed reduction furnace is used to rest the carbon powder to reduce the vacuum process, the crude antimony and lead still contains arsenic, and the reduction slag still contains arsenic. Not a small amount of arsenic (including soluble arsenate and insoluble arsenate) still only achieves the purpose of partial reduction and separation. Whether it is the return of crude antimony to refining or the return of reducing slag as arsenic removal agent, it has caused the cycle of arsenic

Even under strict control of the reaction conditions, the water leached slag separated from the reduced slag after water leaching still contains a certain amount of arsenic, which is still a hazardous solid waste that needs to be treated; the arsenic vapor or arsenic flue gas or elemental arsenic It is easy to be oxidized, especially in the process of forcibly pumping out from the high-temperature furnace with a vacuum pump to cooling. Even if a mixed atmosphere of inert gas and / or nitrogen and hydrogen and / or carbon monoxide is used, it is extremely difficult to recycle and reuse, which will easily lead to economical pollution. Poor performance or air pollution, and the vacuum pump relied on for vacuuming arsenic flue gas has extremely poor adaptability to metal particles or flue gas dust, making it difficult to ensure normal production and operation; or it is necessary to strictly control the equivalent ratio of sodium and phosphate The reaction conditions for the generation of trisodium phosphate are to simultaneously reduce the antimonate and arsenate in the arsenic-alkali slag to elemental antimony and elemental arsenic, but the production control habits of actual antimony smelting enterprises are difficult to guarantee the seemingly simple reaction conditions , and its processing energy consumption is high, and the potential pollution hazard is large, especially the arsenic-containing trisodium phosphate scum can easily flow into the agricultural fertilizer market quietly, resulting in uncontrollable spread of pollution

[0019] To sum up, the separation of arsenic, antimony, and alkali resources in the existing various arsenic-alkali slag treatment processes is relatively difficult, especially the disposal of arsenic is difficult, and problems such as environmental protection and economy are prominent