Method for removing iron ion impurities in copper salt at high efficiency

Abstract

The invention provides a method for removing iron ion impurities in copper salt at high efficiency. The method comprises the following steps of: firstly, adding hydrogen peroxide of which the weight is 1-3% as heavy as that of a copper salt water solution into the copper salt water solution to be treated, adding metastannic acid of which the weight is more than 0.12% as heavy as that of the copper salt water solution, and carrying out absorbing, filtering, evaporating, cooling crystallization, separating and drying to obtain a product. According to the method for removing iron ion impurities provided by the invention, the metastannic acid is taken as a sinking agent, and the metastannic acid is large in specific surface and high in adsorption capacity, so that the iron ion oxidized by the hydrogen peroxide in the copper salt water solution is absorbed in the manner of ferric hydroxide. Compared with the existing deironing technology, the whole impurity-removing technology has the characteristic of being simple to operate, high in impurity removal rate, low in cost, and less in environment pollution. The iron ion impurity content of the copper salt treated by the method provided by the invention can be reduced to be less than 5ppm, so that the method is suitable for being used in the electronic industry and the printed circuit board industry.

Description

technical field [0001] The invention relates to a method for removing impurities, in particular to a method for removing iron impurities in a metal salt solution, and more particularly to a method for efficiently removing iron ion impurities in copper salts. Background technique [0002] Copper salt is an important inorganic chemical product. Its use varies with its purity. For example, copper sulfate pentahydrate, commonly known as bile alum, copper alum or blue alum, can be used in chemical reagents when it is analytically pure, and can be used in petrochemical, industrial, and industrial grades. Electroplating and other industries have a wide range of uses, and can also be used as a mordant for cotton textiles to manufacture green and blue dyes, etc.; and high-purity copper salt products (impurity iron below 10ppm) are the first choice for copper deposition in the electronics industry and printed circuit board industry. important reagents. [0003] Copper salts are usual...

AI Technical Summary

Problems solved by technology

In the jarosite method, the pH value of the jarosite is in the range of 1 to 1.5, and the acidity in the jarosite generation process is increased. When 1 gram of iron generates jarosite, about 1.75 grams are released. Sulfuric acid, so to meet the pH value of jarosite formation, alkali must be used to neutralize the acid produced during the jarosite formation process, and the whole process needs to introduce a large amount of sodium ions, which has complex processes and many influencing factors problems; the neutralization hydrolysis method needs to use expensive high-purity copper carbonate to adjust the pH value of the solution in the range of 3.0 to 4.0, and has the disadvantages of large amount of residue and poor filtration performance of filter residue; in addition, due to the hydrolysis pH of copper and iron The values ​​are all relatively close, and it is difficult to realize that the impurity iron in the copper salt product is below 10ppm by using the jarosite method and the neutralization hydrolysis method; by using the organic solvent extraction method to remove iron, although the iron ion can be reduced to a very low level, it will introduce organic substances into the product, but it is very difficult to completely separate the organic substances in the copper salt solution