Method for recovering refined platinum from crude ammonium chloroplatinate

Abstract

The invention discloses a method for recovering refined platinum from crude ammonium chloroplatinate. The method is carried out according to the following steps of slurrying the crude ammonium chloroplatinate, carrying out heating and adding hydrochloric acid and sodium chlorate to obtain a mixed solution; boiling the mixed solution, adding ammonium chloride, and carrying out filtering after the mixed solution is cooled to obtain the high-purity ammonium chloroplatinate; slurrying the ammonium chloroplatinate, adjusting the pH value to 8-9, and adding hydrazine hydrate to obtain platinum elements; dissolving the platinum elements by using the hydrochloric acid and hydrogen peroxide to obtain a dissolving solution containing the platinum elements; precipitating the dissolving solution by adopting an ammonium chloride fractional precipitation method to obtain the ammonium chloroplatinate, and calcining the ammonium chloroplatinate to obtain sponge platinum; and finally, introducing oxygen into the sponge platinum, then introducing chlorine, carrying out the heating reaction, and heating and decomposing the product under an inert atmosphere, then introducing reducing gas under the inert atmosphere, and keeping constant temperature until the reaction is complete to obtain the metal platinum. According to the method, the ammonium chloroplatinate is refined to obtain the sponge platinum by adopting the hydrazine hydrate reduction-hydrochloric acid and hydrogen peroxide dissolving-ammonium chloride fractional precipitation method, 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.