RU2440429C1 - Method for obtaining concentrate containing rhenium and platinum - Google Patents

Abstract

FIELD: metallurgy. ^ SUBSTANCE: method involves simultaneous extraction of platinum and rhenium from acid solutions by introducing to the solution of sulphur-containing reducing agent (sodium thiosulfate). Then, deposit of sulphides and other connections of rhenium and platinum is separated from the solution. At that, sodium thiosulfate is added in the form of water solution by its uniform continuous supply to hot acid solution containing platinum and rhenium at the ratio of masses of reagent and soluble rhenium and platinum of 15 to 23. ^ EFFECT: reducing the flow of sulphur-containing reagent and increasing the extraction degree of platinum from acid solution to the concentrate owing to changing the procedure of introducing the precipitator reagent to acid solution containing platinum and rhenium. ^ 1 tbl, 1 ex

Description

A method of obtaining a concentrate containing platinum and rhenium from acidic solutions relates to hydrometallurgy of rare and noble metals, in particular to methods for producing concentrates of these metals from solutions containing them.

A known method of processing spent platinum-rhenium catalysts, including their hydrochlorination with transfer to a solution of platinum and rhenium, the subsequent deposition of a concentrate of compounds of platinum and rhenium, and then pyrometallurgical treatment of the precipitate in order to separate them [1].

The main disadvantage of this method is the low extraction of rhenium.

A known method [2] to obtain a concentrate containing rhenium and platinum from acid solutions containing them. The method includes the separation of sulfides and other compounds of platinum and rhenium by treatment with sodium thiosulfate at a ratio of the mass of the reagent and the dissolved platinum and rhenium from 26 to 75 and the subsequent separation of the precipitate from the solution.

This method is the closest in technical essence and the achieved result to the claimed and adopted as a prototype.

The disadvantage of this method is the high consumption of the reagent to achieve a given extraction from a solution of platinum and rhenium.

The technical result, which is achieved by the proposed method, is to reduce the consumption of sodium thiosulfate and increase the degree of extraction of rhenium from an acidic solution into a concentrate by changing the method of introducing a precipitating agent into an acidic solution containing platinum and rhenium.

The desired technical result is achieved by the fact that in the known method for producing a concentrate containing rhenium and platinum from acidic solutions, including introducing sodium thiosulfate into the solution, separating the obtained sulfides and other rhenium and platinum compounds from the solution, sodium thiosulfate is introduced in the form of an aqueous solution by continuous , uniformly feeding it into a hot, acidic solution containing platinum and rhenium with a mass ratio of the reagent and dissolved rhenium and platinum from 15 to 23.

The essence of the method is as follows. In a hot, acidic solution containing platinum and rhenium, sodium thiosulfate is introduced in the form of an aqueous solution by continuous, uniform supply. With this method of introducing the reagent into an acidic solution, a homogeneous mixture is formed immediately and approximately the same concentration of sodium thiosulfate is maintained during the entire time of platinum and rhenium precipitation. With given parameters, sodium thiosulfate is mainly spent on the main reaction - the precipitation of platinum and rhenium sulfides, due to which its consumption is significantly reduced. In addition, a large excess of the reagent per unit volume is not created, which usually leads to the activation of all kinds of adverse chemical reactions with its participation. Specifically conducted studies have shown that to achieve the degree of platinum and rhenium precipitation at the prototype level, this method requires significantly lower consumption of sodium thiosulfate, with a mass ratio of reagent and dissolved rhenium and platinum of 15 to 23. When the mass ratio of reagent and dissolved rhenium and platinum, which is less than 15, the degree of deposition of metals in the precipitate of sulfides decreases, and at more than 23 leads to unproductive consumption of the reagent.

Examples

To obtain a concentrate containing platinum and rhenium, 1.5 M hydrochloric acid with a volume of 0.3 L was used. The concentration of platinum and rhenium in this solution was 0.322 and 0.318 g / l, respectively. The solution was poured into a 0.5 L glass reactor equipped with a stirrer and a reflux condenser, heated to a temperature of 90-100 ° C, and the calculated mass of an aqueous solution of sodium thiosulfate (20 wt.% Na ₂ S ₂ O ₃ · 5H ₂ O in solution). After introducing the calculated mass of the reagent solution, the resulting pulp was warmed up for 10-15 minutes, the precipitate of sulfides and other compounds of platinum and rhenium was cooled and separated from the mother liquor. The residual concentration of platinum and rhenium in the mother liquor determined their degree of extraction. The results of the experiments are presented in the table.

Experience number The mass of the solution of sodium thiosulfate (t / s), g The ratio of M (t / s) / M (Pt, Re) The precipitate,% Pt Re one 19.2 1:20 99.6 98.2 2 9.6 1:10 98.8 67.3 3 28.8 1:30 99.7 98.4

Information sources

1. Bukin V.I., Igumnov M.S., Safonov V.V. and other processing of industrial waste and secondary raw materials containing rare, noble and non-ferrous metals. M .: "Business Capital", 2002, p.165.

2. A method of obtaining a concentrate containing rhenium and platinum from acidic solutions containing them. Pat. RU 2363744, IPC C22B 11/00 (2006.01). Publ. 08/10/2009, bull. Number 22.

Claims (1)

A method of obtaining a concentrate containing rhenium and platinum, including the joint separation of platinum and rhenium from acidic solutions by adding sodium thiosulfate to the solution and separating the precipitate of sulfides and other rhenium and platinum compounds from the solution, characterized in that sodium thiosulfate is introduced in the form of an aqueous solution by continuous uniform its submission to a hot acidic solution containing platinum and rhenium, with the ratio of the mass of the reagent and the dissolved rhenium and platinum from 15 to 23.