Method for recovering and refining platinum from crude ammonium chloroplatinate

Abstract

The invention discloses a method for recovering and refining platinum from crude ammonium chloroplatinate. The crude ammonium chloroplatinate is slurried, hydrochloric acid and sodium chlorate are added, and a mixed solution is obtained; the mixed solution is boiled and kept for a fixed time, ammonium chloride is added, the mixed solution is cooled and filtered, and high-purity ammonium chloroplatinate is obtained; the high-purity ammonium chloroplatinate is slurried, the pH value is adjusted to 8-9 and heating is carried out, hydrazine hydrate is added for reduction, and a platinum element isobtained; the platinum element is dissolved with hydrochloric acid and hydrogen peroxide to obtain a dissolving solution; the dissolving solution is precipitated by adopting an ammonium chloride fractional precipitation method to obtain ammonium chloroplatinate, and the ammonium chloroplatinate obtained in the first step is calcined to obtain sponge platinum; and the sponge platinum is subjectedto deoxygenation treatment, washing and drying to obtain a sponge platinum product. According to the method, impurity elements in the crude ammonium chloroplatinate are removed by adopting an aqueoussolution chlorination method, the ammonium chloroplatinate is refined by reduction of hydrazine hydrate, dissolution of hydrogen peroxide and hydrogen peroxide and fractional precipitation of ammoniumchloride to obtain sponge platinum, and the whole process period is short.

Description

technical field [0001] The invention belongs to the technical field of nonferrous metal smelting, and in particular relates to a method for recovering and refining platinum from crude ammonium chloroplatinate. Background technique [0002] The traditional platinum refining process usually uses a solvent (commonly known as aqua regia) prepared by one volume of nitric acid and three volumes of hydrochloric acid to dissolve impure crude ammonium chloroplatinate under heating and boiling conditions. [0003] In order to realize the complete dissolution of ammonium chloroplatinate, it is necessary to add aqua regia more than 5-6 times, and the aqua regia must be prepared on the spot. The nitrate in the solution must be evaporated completely until it is nearly dry, and then add dilute hydrochloric acid for more than three times as thick as syrup. Finally, add dilute hydrochloric acid to the solution without nitrate and heat to boil to obtain a platinum solution. After cooling , a...

AI Technical Summary

Problems solved by technology

[0004] Due to the traditional platinum refining process, aqua regia is used as the solvent, which makes the dissolution process take a long time, and each process must be heated, resulting in high energy consumption and a large amount of reagents.