Method and device for removing cadmium and thallium from high purity indium production

Abstract

The invention relates to a method for removing cadmium and thallium impurities in the process of producing high purity indium and an apparatus thereof, belonging to the smelting field of high purity non ferrous metal in smelting industry. The specific procedures of the invention are as follows: firstly, putting indium into a crucible and loading the crucible in a vacuum tank, disposing a cylindrical titanium plate on the lid of the crucible, covering a titanium sealing sleeve, folding the cover of the vacuum tank, starting up a water cooling system, and launching a vacuum pump; controlling degree of vacuum below 10 Pa; secondly, controlling temperature of the crucible bottom range from 400 to 1000 DEG C, implementing heat preservation for 1 to 5 hours, volatilizing cadmium and thallium impurities completely, and eventually, remaining the high purity indium in the crucible, thus achieving the objective of purification. The invention has the advantages of fast production speed, low power consumption, simple apparatus processing, and is applicable for large-scale production. As the addition of chemical reagents is not required in the production process, purity of the product is high and the production process is free from pollution and discharge of pollutants.

Description

technical field [0001] The invention relates to a method and a device for producing high-purity indium, belonging to the field of high-purity nonferrous metals in the smelting industry. Background technique [0002] Due to its good light permeability and conductivity, indium is mainly used in the production of ITO targets (for the production of liquid crystal displays and flat panel screens). This use is the main application field of indium, accounting for 70% of the global indium consumption. Several other consumption areas are: electronic semiconductor field, accounting for 12% of global consumption; solder and alloy field accounting for 12%; research industry accounting for 6%. In the application of indium, its purity is required to be above 99.995%, and impurity elements such as cadmium and thallium are required to be below 0.0005%. [0003] The process of purifying crude indium from 98% to 99.99% is mainly electrolysis, but because the potential of cadmium and thallium...

AI Technical Summary

Problems solved by technology

The iodine added in the smelting is also easy to sublimate, and the iodine vapor is very toxic

This method is more polluting to the environment, the operation time is long, the level of impurity removal is low, and the production cost is high. The addition of chemical reagents is easy to bring in new impurities and affect the purity of indium.

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