Method for extracting platinum and rhodium in platinum and rhodium mixed liquid

Abstract

The invention relates to a method for extracting platinum and rhodium in platinum and rhodium mixed liquid. The method comprises the following steps of: extracting the platinum the mixed liquid by taking n-octane as a diluting agent and N-butyl valnoctamide as an extracting agent prepared from solutes and adopting a first-stage extraction method; removing impurities from the rhodium and the impurities contained in raffinate through a cation exchange column to obtain a rhodium solution. According to the method, the platinum is extracted and separated by adopting the first-stage extraction method, and the extraction ratio E of the platinum is more than or equal to 99.5%; the rhodium is extracted by adopting a cation exchange column method. The method disclosed by the invention can be used for efficiently separating the platinum contained in the platinum and rhodium mixed liquid and ensures the extraction purity of the platinum and the rhodium.

Description

technical field [0001] The invention relates to the field of extraction of platinum group metals, in particular to a method for extracting platinum and rhodium in a platinum-rhodium mixture liquid. Background technique [0002] Platinum group metal elements are very rare in the earth's crust, and each ton of solid matter in the earth's crust contains a few tenths of grams to a few tenths of a few grams, the least of which is rhodium, etc., and one ton of solid matter in the earth's crust contains about 1×10 -3 grams of rhodium, a ton of solid matter in the earth's crust contains about 5×10 -3 gram platinum. Platinum and rhodium belong to the platinum group metals. Because of their high melting point, good electrical conductivity, corrosion resistance and high temperature stability, high temperature strength and high temperature creep ability, they become important materials for modern industry and national defense construction. Widely used in aviation, aerospace, missiles...

AI Technical Summary

Problems solved by technology

[0006] In the platinum extraction system prepared by the above-mentioned extractant in industry, the concentration of platinum waste liquid is generally around 10g / L or even lower. The reason is that if the concentration of platinum waste liquid is increased, the concentration of extraction associates formed during the extraction process is high. , leading to turbidity in the extraction system, difficulty in phase separation, and serious precipitation, resulting in the inability to extract and separate platinum, and the extraction system (such as 100% TBP, N235 + n-dodecane + octanol) prepared by the above-mentioned extractant is commonly used at present. It usually takes three to four repeated extractions to achieve a cumulative extraction rate of ≥99.5%. The extraction capacity of the extraction system (including the extraction agent, diluent, acid-base type and its concentration, etc.) is small, and the extraction capacity at one time is weak. Platinum The overall extraction efficiency is low

[0007] Due to the complex and diverse states of rhodium in solution, there is no suitable extractant for extracting rhodium at present.

Because platinum and rhodium are not easy to separate, it is impossible to separate platinum and rhodium using traditional cation exchange column methods and ensure the purity of the extracted rhodium