Preparation method of electrolytic indium sulfate solution used in indium industry

Abstract

The invention discloses a preparation method of an indium sulfate electrolyte used in an indium industry. The preparation method comprises the following steps of: melting refined indium to an indium solution and pouring the indium solution into distilled water for water quenching to indium flowers; adding the obtained indium flowers in batches into heated concentrated sulfuric acid to stir to react till the indium flowers are fully dissolved, leaving the solution to stand to cool after the indium flowers are dissolved, and then depositing an indium sulfate solid after cooling; filtering the cooled indium sulfate to be separated from unreacted sulfuric acid, wherein the separated indium sulfate exists in form of the indium sulfate solid or water-containing indium sulfate crystals; then adding distilled water and sodium hydroxide to adjust the acidity of the solution and stirring the solution till the indium sulfate or the water-containing indium sulfate crystals are fully dissolved to obtain an indium sulfate solution; and finally, adding gelatin and sodium chloride into the indium sulfate solution to prepare the indium sulfate electrolyte. The preparation method for preparing the indium sulfate electrolyte is high in preparation speed and low in cost. The prepared novel electrolyte is supplemented to an electrolytic cell periodically, so that impurities in the electrolyte can be effectively controlled, a standard electrolytic operation is achieved, and the production difficulty of an enterprise is overcome.

Description

1. Technical field: [0001] The invention belongs to the technical field of nonferrous metallurgy, and in particular relates to a method for preparing an indium sulfate electrolyte used in the indium industry. 2. Background technology: [0002] Indium is a silvery-white metal with a slight bluish tinge. It is very soft and can be scratched with a fingernail. Indium is highly malleable and malleable, and can be pressed into pieces. Metal indium is mainly used in the manufacture of low-melting alloys, bearing alloys, semiconductors, point light sources and other raw materials. From room temperature to melting point, indium reacts slowly with oxygen in the air, forming a very thin oxide film on the surface; when the temperature is higher, it reacts with active non-metals. Bulk metal indium does not react with boiling water and alkaline solution, but powdered indium can react slowly with water to form indium hydroxide. Indium reacts slowly with cold dilute acid, and is easily s...

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Problems solved by technology

[0004] Indium sulfate solution is generally heated to 90°C with refined indium (purity above 99.99%) in aqueous sulfuric acid (sulfuric acid concentration 300g / L-500g / L) to melt; due to the physical and chemical properties of indium element, it dissolves slowly in dilute sulfuric acid. It takes a long time (6-8 hours for 1kg of refined indium to completely dissolve), which causes inconvenience to production

[0005] Due to the difficulty in preparing the traditional indium sulfate electrolyte, most domestic enterprises generally maintain electrolytic production by means of periodic circulation and lowering the pH value of the electrolyte, resulting in high impurities in the electrolyte, severe hydrogen evolution, poor quality of precipitated indium, and frequent occurrence of tin and lead in refined indium products. exceed the standard

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