Method for separating antimony and arsenic from antimony and arsenic-containing ash through oxidation and alkaline leaching

Abstract

The invention relates to a method for separating antimony and arsenic from antimony and arsenic-containing ash through an oxidation and alkaline leaching process. The method comprises the specific steps that the antimony and arsenic-containing ash and an alkaline solution with a certain concentration are mixed and then placed in an alkali-resisting and pressure-resisting reaction kettle, and a gaseous oxidizing agent of a certain pressure is introduced into the reaction kettle to conduct a reaction at a certain temperature; after the reaction is completed, liquid-solid separation is carried out when slurry is cooled to the temperature below 90 DEG C, and a liquid phase is returned to the pressure alkaline leaching procedure; a filter cake is subjected to multistage countercurrent washing and filtering with hot water, and arsenic-enriched washing liquid and an antimonite filter cake are obtained; the antimonite filter cake can serve as an antimony concentrate for preparation of antimony oxide powder; and the arsenic-enriched washing liquid is evaporated, then cooled and crystallized, the crystallization end-point temperature and the crystallization time are controlled, arsenate crystals can be obtained after liquid-solid separation, and crystallization mother liquor is alkaline liquor containing a little amount of arsenic and is returned for the leaching process of the antimony and arsenic-containing ash. By means of the method, the process is simple, antimony and arsenic are separated thoroughly, harm caused by arsenic volatilization during the roasting process and arsenic hydride gas produced through the acid leaching process can be avoided, and environmental friendliness is achieved.

Description

technical field [0001] The invention belongs to the technical field of smelting special metal antimony and arsenic. Background technique [0002] In some pyrometallurgical processes, soot containing a certain amount of antimony and arsenic (such as copper blast furnace soot, etc.) is often produced, which has a certain recovery value. Since antimony, arsenic and their oxides are extremely volatile, antimony and arsenic are generally recovered by volatile roasting. For example, using a reverberatory furnace to reduce and volatilize copper blast furnace soot or other slag containing antimony and arsenic can obtain soot with high antimony and arsenic content, in which the content of antimony can reach 10% to 40% (mass fraction), and the content of arsenic can reach 10%. ~60% (mass fraction), with significant enrichment effect. However, due to the ineffective separation of antimony and arsenic in the obtained soot, it is not conducive to the further utilization of antimony and...

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Problems solved by technology

CN102233229A discloses a fire separation method, which uses the difference in volatilization temperature of arsenic trioxide and antimony trioxide to realize step-by-step volatilization, specifically volatilizing arsenic trioxide at 680°C, and then raising the temperature to 850°C to volatilize antimony trioxide ; However, the pyrotechnic process has high energy consumption, the separation of antimony and arsenic is not complete, and there are problems such as arsenic-containing dust pollution

CN1312392 discloses a kind of method of wet separation, and this method adopts Na 2 The mixed alkali solution of S and NaOH leaches antimony and arsenic synchronously, and then 2 o 2 Oxidize the sulfur immersion solution to obtain crude sodium antimonate precipitation and oxidation solution containing sodium arsenate; pickle the crude sodium antimonate precipitation with HCl and neutralize it with NaOH to obtain sodium pyroantimonate, and obtain the oxidation solution containing sodium arsenate by heating Sodium arsenate i

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