Method for separating and purifying rhodium in impurity-containing rhodium solution

Abstract

The invention discloses a method for separating and purifying rhodium in an impurity-containing rhodium solution. The method comprises the following process steps: S1, adjusting the acidity of the rhodium solution to 6-8 mol / L, and adding a prepared DETA solution to obtain filtrate I; S2, adding aqua regia into organic rhodium salt precipitate, heating and dissolving, adding hydrochloric acid to adjust the acidity of the solution to be 6mol / L and the rhodium concentration to be 50-80g / L, heating and boiling the solution, adding ammonium chloride to generate ammonium rhodate chloride precipitate, and quickly filtering to obtain filtrate II; and adding zinc powder into the filtrate to replace rhodium ions in the rhodium solution; S3, removing trace metal impurity ions through hydrogen type cationic resin; S4, adding hydrazine hydrate for reduction to prepare rhodium black; S5, mixing replacement slag, drying, and soaking with 1: 1 hydrochloric acid to remove zinc and other metal impurities; and S6, after filtering, dissolving filter residues with aqua regia, and returning the leachate to a purification process. The method has the characteristics of high direct recovery rate, simple operation process and high purity, and qualified rhodium powder with the purity of more than 99.95% can be obtained after the rhodium black is subjected to hydrogen reduction.

Description

technical field [0001] The invention relates to a method for extracting rhodium, in particular to a method for separating and purifying rhodium in an impurity-containing rhodium solution. Background technique [0002] The methods for separating and purifying rhodium from the solution include sodium nitrite complexation method, ammonification method, potential controlled precipitation method, hydrolysis method, solvent extraction method, etc. Sodium nitrite complexation is one of the most effective methods to remove base metal impurities in rhodium solution, but it is narrow in scope of materials and lengthy in process; ammonification method is based on the reaction of ammonium hexarhodium chlorate and ammonia water to generate pentaammonium dichloride- Precipitation with chlorine and rhodium, but the operation process of this method is cumbersome, and the recovery rate of rhodium is low; the potential control precipitation method will adsorb rhodium during the precipitation ...

AI Technical Summary

Problems solved by technology

But platinum generally exists with four valences in solution, and palladium exists with two valences, and divalent palladium does not react with tetramethylammonium chloride, so this method is limited to the separation and purification effect of the rhodium solution containing platinum and palladium impurities at the same time, and cannot Remove the effect of palladium

In addition, the precipitation operation takes a long time, and it needs to be boiled and refluxed for 36 hours to form a brown precipitate of rhodium, and a sufficient amount of boiling water is required for redissolving

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