SU1533751A1 - Method of extracting platinum metals - Google Patents

Abstract

The invention relates to methods for the recovery of platinum metals and allows the reusable sorbent to be used. The essence of the invention is that the concentrate of platinum metals is decomposed in a mixture of hydrochloric and nitric acids, evaporated, hydrochloric acid is added and evaporated to dryness. After this, the salts are dissolved in a solution of 0.1 M hydrochloric and 0.5 M sulfuric acids and, after preparation, are passed through a sorption column with POLYORGS-XIH or XVH or IVH sorbent at a speed of 10-12 cm ³ / min. From the solution after sorption of platinum metals, nickel, copper, and iron are quantitated. The saturated sorbent is treated successively with a 2-3 M solution of ammonia and a 2-4 M solution of hydrochloric acid, desorbate the platinum group by 50-99%. After desorption, the sorbent is directed again to the sorption of platinoids. 2 hp f-ly, 3 tab.

Description

The invention relates to the recovery of platinum metals, in particular, the separation of platinum metals by sorption on complexing sorbents for further analytical control of non-ferrous metals and iron in platinum-containing materials.

The purpose of the invention is to provide the possibility of repeated use of the sorbent.

Example 1. A portion of a concentrate of platinum metals 0.2-1.0 g decompose 30-40 cm3 mixture of hydrochloric and

nitric acid (3: 1), evaporated to wet salts. 10-15 cm3 of concentrated hydrochloric acid are added to the residue and evaporated to dryness. After this, the salts are dissolved in a mixture of 70-75 cm3 of a solution of 0.1 M hydrochloric acid and 0.5 M sulfuric when heated. After cooling, they are transferred to a volumetric flask with a capacity of 100-200 cm3, brought to the mark with the same solution of a mixture of acids, and the sorption separation of platinum metals from nickel, copper and iron is carried out. The solution is filtered through a dry filter (red ribbon) into a sorption column with a diameter of 3 cm and a height of 18-19 cm, which is placed

POLYORGS-XIH or XVH or IVH sorbent in the form of disks with a diameter of 3 cm and a layer height of 8-9 cm (mass of air-dry sorbent 3.5-4.0 g, transmission speed 10-12 cm3 / min). From the solution after sorption of platinum metals, nickel, copper, and iron are quantitated.

Table 1 shows the results of quantitative determination of nickel, copper and iron in the CO composition of platinum concentrates (POLYORGS-XIN sorbent).

From Table 1 it follows that in the sorption separation of platinum metals, half-exchanges are well consistent with the results of the determination of nickel, copper, and iron with 1–10-fold use of the sorbent.

After the sorbent is saturated with residual amounts of platinum metals (sorption-desorption more than 10 times), the penetration of platinum metals into the solution together with non-ferrous and

Nickel, copper, and gland determinations are overestimated.

After sorption, the platinum metals are desorbed from the sorbent, 80-100 cm3 of 2.5 M ammonia and 3 M hydrochloric acid are passed through the sorbent layer at a rate of 8-10 cm3 / min, then washed with water to pH 0., 1-1 , 0. After that, the sorbent is reused.

Thus, well-matched results from the determination of nickel, copper and iron show the possibility of repeated use of the sorbent in the sorption-desorption cycle (up to 10 times) without destroying it and changing the capacitance characteristics.

Example 2. After sorption separation of platinum metals from nickel, copper and iron, the POLIORGS-IV and POLYORGS-XVH sorbents (with benzimidazole functional groups) or POLYORGS-IV and POLYORGS-XVH sorbents are treated sequentially with an ammonia solution of 2-3 M and 2-4 M solution of hydrochloric acid with sequential processing of the sorbent in artificial mixtures, simulating the composition of real technological products. Quantitative determination of platinum metals in eluates was carried out by the atomic absorption method, the results are presented in Table 2.

ten

„

15

20

thirty

40

35

H 37514

From the table it can be seen that mto sequential desorption of 2.5 M ammonia and 3 M hydrochloric acid gives the greatest degree of extraction in terms of the sum of platinum metals,,: Ft 49,, 7; Pd 99.4-99.5; Rn 47.0-49.2; Rh 46,2-48,5.

The amount of platinum metals in the sorbent remaining after desorption does not affect the subsequent sorption separation. At the same time, the capacitance and kinetic properties of the sorbents used do not change until they are saturated with non-desorbed platinum metals (i.e., under these desorption conditions, the sorbent is used repeatedly in the sorption-desorption cycle). POLYORGS-XIH sorbent containing benzimidazole functional groups in the sorption desorption cycle is used up to saturation 8-10 times. POLYORGS-IVH and XVH with methylpyrazole groups are used 4-6 and 2-4 times, respectively. After desorption with ammonia and hydrochloric acid solutions, the sorbent does not require additional preparation for sorption.

Example 3. The proposed method is carried out using technological products with an established content of noble and ignoble elements and a platinum concentrate GSO composition: GSO 2208-81 - KP-1 platinum concentrate; GSO 23b7 82 - KP-2 platinum concentrate; GSO 2368-82 - KP-3 platinum concentrate.

The results of desorption of platinum metals in technological products are presented in gab3. From this it follows that the use of ammonia and hydrochloric acid solution allows to elute from the sorbent with its repeated use the bulk of platinum metals (50-99%).

The reusable sorption separation of platinum metals on the same sorbent, followed by their desorption, was used to quantify nickel, copper, and iron in

platinum materials (on

an example of a POLYORGS-XIH sorbent operating in a sorption-desorption cycle up to 10 times).

The technical and economic efficiency of the proposed method lies in the fact that, excluding the ashing and resolution of the sorbent, its consumption is reduced by 8-10 times.

515

Claims (3)

1. A method of extracting platinum metals for the subsequent analytical determination of nickel, copper and iron in platinum-containing materials, including sorption on a complexing sorbent containing benzimidazole or 3 (5) -methyl pyrazole groups, characterized in that 37516 repeated use of the sorbent, a sorbent saturated with platinum metals, are sequentially contacted with ammonia and hydrochloric acid solutions. 2. The method according to claim 1, characterized in that use 2-3 M solution of ammonia. five 3. Method pop.1, characterized in that a 2 M hydrochloric acid solution is used. Table 1 1533751 In continuation of tAll