Process for extracting tellurium from copper anode mud

Abstract

The invention discloses a technology for extracting tellurium from copper anode slime, which is characterized by comprising the following steps: (1) the copper anode slime is put into a sulfuric acid solution, oxygen is introduced into the sulfuric acid solution for oxidation sulfuric acid leaching; solid-liquid separation is carried out to obtain leachate containing copper and tellurium; and the leaching process being finished in a closed high-pressure device; (2) copper powder is added into the leachate to remove silver or selenium in the leachate by substitution, and the solid-liquid separation is carried out; (3) sulfur dioxide is introduced into the leachate obtained from the step (2) to precipitate the tellurium by reduction, and the solid-liquid separation is carried out to obtain crude tellurium; and (4) the crude tellurium is processed according to a conventional method to extract pure tellurium. The technology adopts one-section oxidation acid leaching to leach the copper and tellurium out, copper powder to remove the impurities of silver, selenium and the like by substitution, and sulfur dioxide to precipitate the tellurium by reduction (obtaining tellurium dioxide), and the tellurium dioxide precipitation is alkali-dissolved and then electrolyzed to obtain the tellurium, therefore, the flow is simple, the consumption of the copper powder is remarkably reduced, and the simplification of the technology is beneficial to improve the recovery ratio of the tellurium, which can achieve more than 90 percent.

Description

technical field [0001] The invention relates to a wet extraction process of scattered elements, a process for extracting tellurium from copper anode slime. Background technique [0002] At present, there are mainly two kinds of copper anode slime treatment processes at home and abroad: one is the (semi) wet process which is based on the wet method and combines the fire method and the wet method. This process is currently adopted by most domestic manufacturers. The main process It is "copper anode slime - sulfuration roasting and steaming selenium - dilute acid separation of copper - alkali leaching and separation of tellurium - electrolytic preparation of metal tellurium - chloride separation of gold - sodium sulfite separation of silver - gold and silver electrolytic refining", such as Jiangtong Guixi Smelter, Tongling Nonferrous Metals Metal companies, etc.; the second is the pyrotechnic process based on the fire method, which combines the wet method and the fire method. ...

AI Technical Summary

Problems solved by technology

The disadvantages are: (1) two-stage leaching of copper and tellurium, the process is complex, and acid and alkali are used alternately, resulting in increased consumption of chemicals, difficult wastewater treatment, and is not conducive to factory operation and management; (2) low recovery rates of selenium and tellurium, selenium, Tellurium recoveries are 90% and 85% respectively

The disadvantages are: (1) two-stage leaching of copper and tellurium, the process is complicated; (2) copper powder replaces the precipitated tellurium, and the obtained copper telluride needs to go through two stages of leaching (the first stage of oxidative acid leaching of copper, the second stage of alkali leaching tellurium), and then electrolyze tellurium from the alkali immersion solution, not only the process is complicated, but also a large amount of copper powder needs to be consumed

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