A method for deep recovery of tellurium by cascade swirl electrolysis

Abstract

The invention discloses a method for deep recovering of tellurium through cascade cyclone electrolysis. The method comprises the following steps: carrying out primary cyclone electrolysis on an electrolyte prepared from tellurium dioxide and an inorganic strong alkali solution, and obtaining a primary electrolytic cathode tellurium and a primary electrolytic post-solution when the tellurium concentration in the electrolyte reaches a primary electrolysis end point; carrying out secondary cyclone electrolysis on the primary electrolytic post-solution, and obtaining secondary cathode tellurium and a secondary electrolytic post-solution when the concentration of tellurium in the primary electrolytic post-solution is reduced to a secondary electrolysis end point; uniformly mixing and crushing the primary cathode tellurium and the secondary cathode tellurium, and then carrying out ultrasonic washing to remove impurities so as to obtain a 4N cathode tellurium product. According to the method,large current density is adopted in the primary cyclone electrolysis, the electrolysis period is remarkably shortened, and the tellurium electrolysis efficiency is improved; a relatively common current density is adopted in secondary cyclone electrolysis, co-deposition of impurity elements Pb and Se is strictly controlled, the recovery rate of tellurium is greatly increased, and circulation and overstock of tellurium in an electrolysis system are powerfully reduced.

Description

technical field [0001] The invention belongs to the field of rare metal metallurgy, and in particular relates to a method for deeply recovering tellurium by cascade swirl electrolysis. Background technique [0002] Tellurium is an important scattered metal. Due to its excellent thermoelectric and photoelectric properties, it is widely used in metallurgy, chemical industry, electronics, glass, photovoltaics and medicine, and is a supporting material for contemporary high-tech. Especially as the basic material of cadmium telluride thin-film solar cells, the demand for tellurium continues to grow rapidly. [0003] The abundance of tellurium in the earth's crust is only 6×10 -6 , no independent tellurium ore with industrial mining value has been found. Tellurium is mainly associated with copper and lead sulfide ores. Currently, tellurium is mainly recovered from copper anode slime as a by-product. [0004] The main process flow of tellurium recovery is ball milling→water imm...

AI Technical Summary

Problems solved by technology

[0005] According to the research and analysis of the inventor, the main problems in tellurium electrolysis are as follows: ① the requirement for the concentration range of tellurium in the electrolyte is relatively high

② The current density of the electrolysis process is 40-60A / m 2 , the electrolysis speed is low, and the electrolysis cycle is long

②The primary direct recovery rate is low, only 50-60%. A large amount of tellurium circulates and backlogs in the electrolysis system along with the neutralization, purification, precipitation, liquid production, and electrolysis of the post-electrolysis solution, resulting in relatively high production costs. High consumption

This invention patent is electrolyzed at low tellurium concentration and high current density, Pb, Se and other impurities and tellurium are co-deposited on the cathode, resulting in low current efficiency, only 60-70%; and the tellurium concentration in the electrolyte is only 10-20g / L, resulting in low equipment capacity and utilization

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