A method for enriching and purifying indium from acid leaching solution containing ito waste by salting out

Abstract

The invention discloses a method for enriching and purifying indium from an ITO-containing waste acid leaching solution by utilizing salting-out, and belongs to the technical field of recycling and utilization of ITO-containing waste materials. Adjust the hydrochloric acid system containing ITO waste, and then add a salting-out agent; use A336NO3 to extract, separate the liquid and remove impurities, and realize the separation of the ionic liquid phase 1 of Fe3+ and Sn2+ from the raffinate 1 containing In3+; wash and purify the ionic liquid phase with hydrochloric acid 1 after recycling, NaOH adjusts the acidity of raffinate 1 and then adds A336NO3 to extract and recover indium; the obtained oil-liquid mixed phase 2 separates and removes impurities, and obtains ionic liquid phase 2 and tail liquid 2 containing In3+; ionic liquid Phase 2 is eluted with hydrochloric acid to obtain a high-purity In enrichment solution, and the purified ionic liquid phase 2 is recycled. The invention is based on an ionic liquid extraction system, utilizes the salting-out effect to adjust the anion system in the solution, realizes efficient separation of impurity tin and iron, and efficient enrichment and purification of indium.

Description

technical field

[0001] The invention belongs to the technical field of recycling ITO-containing waste materials, in particular to a method for enriching and purifying indium from an ITO-containing waste material pickling solution by using salting-out. Background technique

[0002] As a rare metal, indium reserves are extremely rare worldwide, and its abundance in the earth's crust is only 4.0×10 -8 , is 1 / 6 of gold, and the primary ore with a grade of more than 0.002% has the value of smelting, and has been listed as a strategic reserve resource by various countries. Indium and its compounds have good electrical conductivity and light transmission, and more than 75% are used in ITO thin films (In 2 o 3 :SnOx=9:1) preparation of product.

[0003] Usually, the largest amount of ITO waste comes from LCD glass and ITO targets. Therefore, typical ITO-containing waste refers to waste liquid crystal displays and ITO waste targets. Because the amount of indium is much higher tha...

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