Preparation method for silica gel-loaded aminomethylpyridine chelating resin for deep copper removal

Abstract

The present invention relates to a preparation method for a silica gel-loaded aminomethylpyridine chelating resin for deep copper removal. According to the method, a silicane coupling agent reacts with 2-aminomethylpyridine under an anhydrous condition to generate an aminomethylpyridine modified silicane coupling agent; the aminomethylpyridine modified silicane coupling agent is grafted onto the surface of the activated silica gel. With the method of the present invention, the loading and the metal ion adsorption capacity of the functional groups of the chelating resin are effectively improved; the synthetic route is simple and economical. In addition, in the existing synthetic route, when silicon dioxide with the surface modification of the amino groups reacts with nitrapyrin to prepare the chelating resin, the alkality of the reaction system is high (the pH value is more than 11), and the silicon dioxide is dissolved, or the alkality of the reaction system is low (the pH value is less than 10), the nucleophilic substitution reaction efficiency between the nitrapyrin functional group and the amino group is low, and the loading of the functional group is not high. With the method of the present invention, the problems in the existing synthetic route are avoided.

Description

technical field [0001] The invention relates to a preparation method of a resin with strong selective chelation for copper ions, in particular to a preparation method of a deep copper-removing chelation resin loaded with aminomethylpyridine on silica gel. Background technique [0002] In cobalt metallurgy, in order to obtain high-quality electrolytic cobalt products, the cobalt electrolyte must be deeply purified to remove copper. This is because the standard potential of copper (+0.337V) is much more positive than that of cobalt (-0.28V). When the cobalt electrolyte contains copper ions, the copper ions are reduced on the cathode, so that the cathode electrode cobalt product cannot reach high-quality electricity. Cobalt requirements. The commonly used purification and copper removal methods for cobalt electrolyte mainly include chemical purification, extraction, ion exchange, and chelating resin adsorption. Among these methods, the chelating resin adsorption method has th...

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Problems solved by technology

Due to the large steric hindrance of alkoxy groups and the small specific surface area of ​​silica, the halogen group loading efficiency is low (P.K.Jal, S.Patel, B.K.Mishra, Chemical modification of silica surface by immobilization of functional groups for extractive concentration of metal ions)

At the same time, our research has found that when the chloromethylpyridine functional group is grafted onto the surface of silica loaded with amino groups on the surface, there are strict requirements on the pH value of the reaction system, and too high alkalinity (pH value greater than 11) will Dissolve the silica gel, and when the alkalinity is too low (pH value below 10), the efficiency of the nucleophilic substitution reaction between the chloromethylpyridine functional group and the amino group is low, which directly leads to a low loading of the functional group

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