Method for leaching tellurium in tellurium slag in co-oxidation mode

Abstract

The invention discloses a method for leaching tellurium in tellurium slag in a co-oxidation mode. The method comprises the following steps that 1, sodium chloride is added into a sulfuric acid solution and heated to 60 DEG C-90 DEG C, heat preservation is conducted, then, ozone is introduced, the tellurium slag is added, and stirring is conducted; and 2, under the condition that stirring is kept, hydrogen peroxide is introduced into the solution processed in the step 1, the solution and the ozone are subjected to oxidizing leaching in a synergetic mode, and solid-liquid separation is conducted after reaction lasts for 2-8 h, so that leaching slag and leaching liquid containing the tellurium are obtained. According to the method for leaching the tellurium in the tellurium slag in the co-oxidation mode, hydroxyl radicals very high in oxidizing capacity are produced under an O3 / H2O2 system; the stable structure of lead telluride and the stable structure of bismuthic acid copper are opened through the high oxidizing property of the hydroxyl radicals, so that the tellurium, bismuth and copper are exposed; the chlorine benignity characteristic of the tellurium and the bismuth is utilized, so that the leaching effect of the tellurium, the bismuth and the copper in the tellurium slag is good, the leaching rate of the tellurium reaches 99%, the leaching rate of the bismuth reaches 96%, and the leaching rate of the copper reaches 99%; and accordingly, the tellurium in the complex tellurium slag is efficiently and directly leached, and step-by-step recycling of the tellurium, the bismuth, the copper and antimony is facilitated.

Description

technical field [0001] The invention relates to a method for synergistically oxidizing and leaching tellurium in tellurium slag, in particular to a hydrometallurgical method for realizing synergistic leaching of tellurium slag and effective separation and enrichment of valuable metals. Background technique [0002] Tellurium is an important scattered metal. Due to its special physical and chemical properties, it is widely used in many fields such as metallurgy, chemical industry, petroleum, electronics, electrical, glass ceramics, pigments and medicine, especially telluride has high thermoelectric potential And good photoelectric conversion performance, making the development of tellurium in semiconductor refrigeration parts and solar energy particularly rapid. At present, tellurium is mainly recovered from copper concentrate and lead concentrate. After the copper concentrate or lead concentrate is treated by pyro-smelting electrolytic refining process, tellurium is enriched...

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Problems solved by technology

[0003] The phases of tellurium in tellurium slag are different, and the methods adopted are different. When the phases of tellurium in tellurium slag are mainly tellurium dioxide and sodium tellurite, the method to be adopted is alkaline leaching method, which is not suitable for tellurium dioxide. The treatment effect of tellurium slag with high content of sodium tellurite is good, but for the tellurium slag containing sodium tellurate and telluride, the effect of this method is relatively poor

For the tellurium slag containing sodium tellurate and telluride, the method adopted is oxidative acid leaching method, which is mainly in sulfuric acid medium, and the tellurium in sodium tellurate and telluride enters the solution through the oxidant, but the conventional oxidant is used to oxidize During acid leaching, the leaching rate of tellurium is less than 80%, while when leaching with potassium permanganate, although the leaching rate of tellurium can reach 90%, impurity ions are introduced, which increases the difficulty of subsequent separation and recovery of tellurium

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