Method for recovering antimony, arsenic and alkali from secondary arsenic alkaline residue

Abstract

The invention relates to a method for recovering antimony, arsenic and alkali from secondary arsenic alkaline residue. The method comprises the following steps of (1), adding the secondary arsenic alkali residue and a reducing agent into a crucible, conducting mixing, putting the mixture into a reaction furnace, introducing inert gas, and conducting stirring and heating; and (2), receiving arsenicsteam containing antimony in the upper part of the reaction furnace, conducting cooling, crystallizing and dust collecting to obtain an antimony-containing crude arsenic product, discharging reactionalkali residue from the outlet of the lower part of the reaction furnace, and cooling to obtain sodium oxide. The method can be used for effectively, thoroughly and harmlessly treating the secondaryarsenic alkali residue, can accelerate the treatment of a large amount of secondary arsenic alkali residue which is overstocked currently, and has good environmental protection benefits and social benefits; the sodium oxide obtained through the method can be used as a glass manufacturing raw material and has relatively good economic benefits; and meanwhile, the method is short in technological process, convenient to operate, free of secondary pollution, less in investment, fast in effectiveness and suitable for industrial treatment of the secondary arsenic alkali residue.

Description

technical field [0001] The invention relates to a method for comprehensive recycling of arsenic-alkali slag, in particular to a method for recycling antimony, arsenic and alkali through secondary high-temperature pyrotechnic harmless treatment of arsenic-alkali slag. Background technique [0002] In the process of antimony smelting, a large amount of primary arsenic-alkali slag with high content of antimony and arsenic will be produced due to the removal of arsenic by refining. The residue after antimony is called secondary arsenic-alkali residue. The antimony content of secondary arsenic-alkali residue is generally about 1%, and the arsenic content is generally in the range of 6-20%. The secondary arsenic-alkali slag can be leached conventionally, most of the arsenic is leached in the form of sodium arsenate, but about 0.5%-4.0% of arsenic cannot be leached, and the antimony content in the leached arsenic-alkali slag is about 2% . This kind of slag is very difficult to de...

AI Technical Summary

Problems solved by technology

This kind of slag is very difficult to deal with, antimony is difficult to achieve industrial recycling, and arsenic cannot meet the national standard for external heaping, so it cannot be externally heaped, and it can only be stored permanently. Due to the high content of arsenic in sodium phosphate products, it is difficult to take out because there is no market, and they can only continue to be stored permanently. Therefore, the conventional leaching method of arsenic-alkali slag has not achieved the purpose of comprehensive utilization, and the environmental protection problem still cannot be completely solved.

[0003] CN201110320455.8, CN201210060719.5, CN201210137936.X disclose the method of separating antimony and arsenic in arsenic-alkali slag by hydrothermal leaching, antimony and arsenic valence state control, and high-temperature step-by-step crystallization and precipitation of arsenic-alkali slag to separate arsenic-alkali slag , the separated arsenic-alkali slag is dried to obtain sodium carbonate and sodium arsenate, which basically realizes the comprehensive recycling of antimony, arsenic and alkali in the arsenic-alkali slag, but there are several problems at the same time. The slag contains arsenic ≤ 0.5%, but it is still not thorough enough; two, the sodium carbonate of the obtained waste alkali slag contains arsenic ≤ 0.6%, which also affects the re-application of sodium carbonate; three, sodium arsenate, due to the strict requirements of environmental protection, cannot As a product for export and inventory, it cannot be disposed of, and there is a problem of environmental protection and secondary pollution

[0004] 201711471870.7 discloses a reduction smelting treatment method of arsenic-alkali slag. The carbon reduction smelting of high-antimony arsenic-alkali slag is carried out at 10~101325Pa, 900~1200℃ for 1-8 hours to prepare antimony, arsenic, and alkali sodium carbonate. The primary arsenic-alkali slag (containing 26.2% antimony, 9.68% arsenic, 5.85% lead, and 22.88% sodium) was treated, but the treatment of the secondary arsenic-alkali slag was not involved

If the above method is used to treat the secondary arsenic-alkali slag, the antimony existing in the form of sodium antimonate in the arsenic-alkali slag will be reduced at a very slow rate at 900~1200°C, making it difficult to recover and easily entrained in the secondary arsenic-alkali slag In the process, most of the antimony still exists in the arsenic-alkali slag, and a small part of the antimony can be reduced, so it is still impossible to realize the comprehensive recovery and utilization of antimony resources.

[0005] In a word, the current wet and pyroprocessing of arsenic-alkali slag cannot effectively recover antimony, arsenic, and alkali in secondary arsenic-alkali slag, especially it is difficult to effectively recover antimony, because the antimony content of secondary arsenic-alkali slag is relatively low. less antimony, it is difficult to recover antimony, and the reserves of secondary arsenic-alkali slag at home and abroad are huge, so it is urgent to find an effective and harmless method for recovering secondary arsenic-alkali slag