A kind of method for preparing tellurium powder

Abstract

The invention discloses a method for preparing tellurium powder. The method comprises the following steps that (1), tellurium dioxide is added to a sodium hydroxide solution, and stirring and then filtering are conducted; (2), the solution filtered in the first step is used as electrolyte and subjected to rotational flow electrodeposition, and after electrodeposition is completed, the electrolyte is filtered, and an electrodeposition product is obtained; and (3), the electrodeposition product obtained in the second step is added to an oxalic acid solution and boiled and washed, and the tellurium powder is obtained after filtering and drying. According to the method, the rotational flow electrodeposition technology is used for the preparation of the tellurium powder for the first time, the flow velocity of the solution is increased with the help of the electrodeposition technology, the tellurium ion concentration of the surface of an electrode is increased, the thickness of a diffusion layer is lowered, the limiting current density is increased, electrodeposition precipitation of tellurium in the solution with the low tellurium content under the high current density is achieved, and the method is a process which is economical and environmentally friendly and is suitable for industrial production.

Description

technical field [0001] The invention belongs to the field of metallurgy, in particular to a method for preparing tellurium powder. Background technique [0002] Tellurium is one of the indispensable materials in modern industry and high-tech industry. It is known as the vitamin of modern industry, national defense and cutting-edge technology. It is widely used in chemical industry, metallurgy, medicine, glass ceramics, electronic appliances, national defense, energy and other fields. [0003] Industrial tellurium is mainly used as a metallurgical additive, which can effectively improve the cutting performance of low-carbon high-speed cutting steel and high-strength steel; improve the electrical conductivity, thermal conductivity and fatigue resistance of copper-based alloys; improve the corrosion resistance, hardness and strength of lead-based alloys. [0004] High-purity tellurium is also an important photoelectric and thermoelectric material. In the photoelectric field, Pb...

AI Technical Summary

Problems solved by technology

The above two methods have their own defects. The use of chemical methods to prepare tellurium powder requires a large amount of chemical reagents and high production costs. After the reaction, a large amount of sodium sulfate and sodium chloride remain in the liquid, which is difficult to recycle and pollutes the environment.

Tellurium powder is prepared by electrolysis, and the tellurium concentration at the end of the electrolyte is about 100g / L. It is necessary to return to the acid neutralization step to prepare tellurium dioxide again, resulting in the consumption of a large amount of acid and alkali; part of the tellurium is oxidized to sodium tellurate, which is difficult to recover. The direct recovery rate of tellurium is low, only 60-70%