SU980812A1 - Method of recovering noble metals from solutions - Google Patents

Description

The invention relates to a process for the recovery of noble metals from solutions and can be used in non-ferrous metallurgy to more completely isolate the noble metals from their nickel-cobalt and copper process solutions.

Platinum metals, gold and silver are in solutions of electrolytic nickel refining baths, as well as in solutions of electrolyte sludge processing into platinum concentrates in the form of solid fine particles and in dissolved ionic form.

The selection of noble metals from primary solutions reduces their losses in subsequent processing with recycled products.

A known method of extracting sludge from anolyte nickel proizvodstvv by filtering it on a candle. filters with filtering elements of porous chamotone-concrete ceramics W.

The main mass of sludge is released on the filters, however, the filtration quality is low and the content of fine suspension in the filtrate is about 10 mg / l. Also in the filtrate

platinoids remain in the ionic form (up to 30-50% of the initial).

A known method for the recovery of metals by sorption with various ionites f.

However, to implement the known method, special equipment is required. In addition, the presence of fine sludge particles in

10 solutions significantly reduces the exchange capacity of sorbents.

The closest to the invention in technical essence and the achieved result is the method of extracting noble metals from solutions, including filtering solutions, through a filtering element with a porous polyethylene partition and with a special container,

20 in which there is a filtering material that provides chemical treatment of chlorine compounds and other elements H.

However, due to the fact that the poly25 ethylene filter and chemical filter are structurally separated, the device becomes more complex and requires additional capital and operating costs. In addition, the method of metal extraction by two-stage filtration does not allow the extraction of trace elements from solutions, such as platinum metals. The aim of the invention is to increase the degree of extraction of platinum metals and to make the process cheaper. According to the method for extracting precious metals from solutions, including filtering through a porous filter element from sintered polyethylene, filtering is carried out through an element made in the form of a high-molecular weight sintered cartridge. polyethylene with a pore size of 5-15 microns, filled with a sorbent with a grain size of 450-700 microns. An increase in the degree of extraction of platinum metals is achieved due to the complete release of platinum-containing solid particles on a porous filter element from sintered high-molecular-weight polyethylene (PMP) with pore sizes of 5-15 µm and due to sorption of platinum compounds in ionic form on sorbent grains placed inside an item. The technology became cheaper due to the preservation by the sorbent of a high exchange capacity for platinoids, which is provided by fine cleaning of the solution on the porous HFM from mechanical impurities. The grain size of the sorbent in the swollen state should be in the range of 450-700 µm, the excess of the sizes is connected with the reduction of the assigned active surface of the grains, the reduction of the grain size below 450 µm increases the hydraulic resistance on the drainage grid. The pore sizes of sintered HFM are limited to 5–15 µm under favorable circumstances: the upper limit provides for the fineness of cleaning the solution from mechanical impurities (0.1 mg / l), the lower limit is due to the need to maintain sufficient permeability of the filter septum (1.5–2 ), which provides almost complete capture of platinoids with a minimum amount of equipment. A solution characteristic of technological processes in nickel-cobalt production was used in the processing of sludge, containing, g / l: nickel 86.2; cobalt 0.32; iron 0.33; - copper 52,6; chlorine ion 40.6; sulfuric acid 10.2; solid suspension, 46 mg / l, noble metal content in the solid phase,%: rhodium 14.8; iridium 17.7; ruthenium 15.6; content of noble metals in the dissolved state, mg / l: rhodium 4,3; iridium 11.4; ruthenium 5.6; in the amount of 21.3. The solution is fed under a pressure of 2.4-2.6 mg / cm2 to a cartridge filter equipped with one filter cartridge in the form of a hollow cylinder 2 with walls and a bottom made of a high-frequency magnetic material with a pore size of 5-15 μm. The cartridge is filled to the top with a layer of 3 grains of resin brand AMP, prepared by known methods, the grain size of the resin is 450-700 microns. The mouth of the cartridge is blocked by a stainless steel drainage mesh of smooth fabrication No. 160 (GOST 3187-76). The flow rate of the solution through the filter on average for 40 hours of operation is 32 l / h. In control experiments at approximately the same flow rate, variants without filling the cartridge with resin and filling the cartridge with resin with a pore size of 30-45 µm were carried out. Data on the degree of extraction of platinum metals are presented in the table.

0.2

0.4 0.1 0.3 0.1 0.3 0.1 0.3 0.1 0.35

0.2

3.6

21.3 0.1 21.3 3.2 0.1 21.3 2.5 0.1 21.3 2.5

The results of the experiments show, as follows from the presented data, that filtration through fine-porous PMF and sorbent allows to achieve high recovery of platinum metals from the solution (about 99%), the amount of platinum satellites in the leakage and the filtrate more than 3 mg / l is detected after cleaning 1000 l of solution that corresponds to the exchange capacity of the sorbent 5%. The same amount of resin, placed in the cartridge of the high-precision magnetic fluids with a pore size of 30-45 microns, completely omitted only 200 liters of dissolved platinoids after cleaning, which corresponds to the use of a sorbent exchange capacity of less than 1.0%,

Thus, with the use of HFM with a pore size of 5–15 µm, a significant reduction in the consumption of AMP resin (5–6 times) is achieved, the technical and economic effect is due to an increase in the degree of extraction of platinum satellites by 0.1–0.2%, a decrease in the ion-exchange rate. resin 5-6 times and reducing the size of the equipment by 25-3t)%.

Table continuation

Claims (3)

1.Plaksin N.N., Popkov I.N. Izv. universities. Tsvetna metallurgists, 1963, p. 5.57. 2. Eelikman A.N., Voldman G.M. Bel vska LB Theory of hydrometallurgical processes. M., Metallurgists, 1975, p. 260 3. The UK patent number 1314710, cl. B 01 0. 15/00, 1973 (prototype).