CS232583B1 - Method of processing secondary raw materials containing precious metals - Google Patents

Abstract

The method relates to the recovery of platinum-rhodium and copper alloys. First, the secondary raw material is converted into a separable form, e.g. by burning the flammable component or by subcooling to a cryogenic temperature, after which the thermally treated raw material is ground and sorted on a sieve. The undersize fractions obtained are gravitationally separated in the form of a suspension into a heavy fraction containing precious metals, and the oversize fractions are magnetically separated. The first concentrate of precious metals is obtained from the magnetic product by mechanical treatment. At the same time, the non-magnetic product with the heavy fraction from the gravitational separation is selectively freed from non-ferrous metals and impurities by at least one-stage chemical treatment and is thus converted into another concentrate of precious metals. The combined concentrates of precious metals are leached in an inorganic acid, or in mixtures thereof, and thus the final concentrate is obtained.

Description

VEJNAR PAVEL ing. CSc., KENCLOVA ZDENA, MNISEK POD BRDY,

HORÁK VÁCLAV ing., PRAGUE, MALINA JOSEF, PRAGUE (54) Processing of secondary raw materials containing precious metals

The method relates to the recovery of platinum-rhodium-copper alloys. First, the secondary feedstock is converted into a releasable form, e.g., by burning the flammable component or subcooling to a cryogenic temperature, after which the heat-treated feedstock is ground and screened. The undersized fractions obtained are broken down by gravity in the form of a suspension and a heavy fraction containing precious metals is separated and the oversize fractions are magnetically separated. The first precious metal concentrate is obtained from the magnetic product by mechanical treatment. At the same time, the non-magnetic product with a heavy fraction from gravity separation by at least a one-stage chemical treatment is selectively freed of non-ferrous metals and impurities and thereby converted to a further precious metal concentrate. The combined precious metal concentrates are leached in the inorganic acid or mixtures thereof to obtain the final concentrate.

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The invention relates to a process for the treatment of multi-component secondary raw materials containing precious metals and / or their alloys, in particular thermosondes.

Many industrial sectors use products such as measuring instrument components that contain precious metals and their alloys. After losing their functional properties, these products are then transferred to secondary raw materials · It is already known to process secondary raw materials containing metals and plastics, eg waste cables, which are first granulated, eg · cutting * and then separate in several stages their individual folders. In these processes, said feedstocks usually contain a single metal component, even in an amount of the order of 10%. However, in those cases, they are multi-component systems with a relatively low content of precious metals consisting of several metal components, insulating materials such as glass, ceramics, sealants, rubber, plastics and possibly other components obtained during use of the product , the industrial process of processing into a precious metal concentrate is difficult or unknown. Usually, the recovery of precious metals from these secondary raw materials is done only by hand disassembling and sorting the raw material.

The above-mentioned shortcomings are eliminated by the method of processing of secondary raw materials containing precious metals, especially thermosondes. According to the invention, the principle is that the secondary raw material is first converted into a releasable form, for example by burning a combustible component. The heat-treated raw material is ground and screened on a 0.1 oz 50 mm sieve and the subnets obtained are suspended in the form of a suspension by gravity, for example to shake the weir, into a heavy fraction containing precious metals. The oversize fractions are magnetically separated and a precious metal concentrate is obtained from the obtained magnetic product by mechanical treatment, for example by screening. At the same time

232 583 are the aomagnetic product together with the heavy fraction from gravitational separation by at least a one-stage chemical treatment selectively frees non-ferrous metals and impurities and is thus converted into another precious metal concentrate. According to another embodiment of the invention, the secondary raw material is converted to a releasable form by cryo-lowering to the cryogenic temperature, after which it is washed before being dried.

under the corner of your finger on the quarry.hr icLo d & & /,

The combined precious metal concentrates are leached in inorganic acid or in mixtures thereof, thereby obtaining an undersized concentrate containing at least 95% by weight, precious metals »

The process according to the invention is simple and allows, in contrast to many manual processes used hitherto, with a high yield and economically advantageous processing of secondary raw materials with a very low content of the precious metal component.

The following are two exemplary embodiments of the method of the invention. Example 1

54.7 kg of spent ternesonds used previously to measure the temperature of the molten metal baths were freed from the resilient polyethylene casing in a thermally self-supporting thermal manner and converted to crushable form. The fired portion, with a eea of 70% by weight, was milled in a ball mill and the milled material obtained was screened to a 1.5 mm mesh size. A predominantly silicate content, with a yield of 87.6% by weight, was mixed with science. The resulting suspension was blown in cone n by gravitationally resonance on a two-storey shaking weir. The heavy fraction, consisting of fine wire strands of platinum-rhodium Pt-Rh alloy and copper plungers, exhibited a mass yield of 2 (53 S6) in the next stage, free of copper leaching in the HgO-CO3-NH3 system while oxidizing with air oxygen.

After washing and drying, a platinum-rhodium Pt-Rh alloyancentrate was obtained practically free of other impurities with a weight yield of 0.072%. The wires, obtained with a weight yield of 10.1%, were converted into a precious metal concentrate by merely screening to 5 mm sieves and the sub-screen magnetically separated. Weight

232,563 the yield of the non-magnetic product was 0.0084%. Non-magnetic product from the first magnetic separation whose mass yield was

2.3%, containing predominantly copper and precious metals, was, similarly as heavy part of the gravity treatment, reworked chemically by leaching to a platinum-rhodium alloy concentrate with a mass yield of 0.048

Concentrates of precious metals obtained from leaching and non-magnetic product by leaching and from magnetic product were finally reworked together by leaching in hydrochloric acid to give virtually pure platinum-rhodium alloy wires.

Treatment of 37.9 kg of tanned thermosondes was obtained

3500 g of iron

1585 g of Cu concentrate (Cu copper content 61.2%)

42.2 g of platinum-rhodium Pt-Rh wires

32900 g of ceramic material Example 2

24.6 kg batch of spent Thermal probes originally used to measure the temperature of molten metal bath has been cooled to cryogenic temperatures © in liquid nitrogen and at a temperature below pedchlazení -80®C crushed to hammer mill crushing ₀ product was sized on a sieve of the / i ^ 5 mm. The undersize product, whose weight yield was 61.3, was ground in a ball mill to a grain size below 1.5 mm. This fraction was treated in the same manner as the fractions of fraction < 1.5 m in Example 1, e.g. in the form of a suspension on the shaking weir and the obtained heavy product was stripped of copper.

The supernatant fraction from screening with a weight yield of 38.7% was subjected to magnetic gseparation, whereby the magnetic product, with a weight yield of 6.7%, was processed as in Example 1 by merely screening to a mesh size of 5 mm. The non-magnetic product, with a weight yield of 32.0%, was gravitationally separated, yielding a light product of a crushed polyethylene shell with a weight yield of 31.3% and a precious metal concentrate with a weight yield of 0.65% which was chemically reworked as heavy the gravity treatment product of Example 1, i. The leach was stripped of copper and a precious metal concentrate was obtained.

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Combined precious metal concentrates of bullfinches have been chemically treated by leaching in hydrochloric acid ®31 as and Example 1 «

By processing 24.6 kg of thermosonders, these products were 1500 g of body

Hall g Cunkoneentrate (65.1% copper Cu)

18.7 g Pt-Hh platinum-rhodium wires

7700 g crushed plastic wicks

14250 g of ceramic material

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object of the invention

Claims (3)

1. A method of treating secondary raw materials containing a precious metal, in particular a thermo probe, characterized in that the secondary raw material is first converted into a separable form, for example by burning a combustible component, after which the heat treated raw material is ground and screened on a 0 , 2-50 mm, and the obtained undersize material was in the form of a suspension by gravity disintegrated, e.g., n ^ earthshatterring weir, into a heavy fraction containing precious metals and oversize fractions are magnetically separated from the resulting magnetic Kehoe product to mechanical treatment, e.g., _by sorting on a sieve , the precious metal concentrate is obtained, and at the same time, the non-magnetic product, together with the heavy fraction from gravity separation, is at least one-stage chemically treated to selectively remove non-ferrous metals and impurities, thereby converting it to the next precious metal concentrate » 2. The method according to claim 1, characterized in that the secondary crude is converted to a separable form by subcooling to cryogenic temperature, and then the subnets are subjected to a granulometric treatment prior to gravitational separation. 3o A process according to claims 1 and 2, characterized in that the combined precious metal concentrates are leached in the inorganic acid or mixtures thereof, thereby obtaining a purified concentrate containing at least 95% by weight of the precious metals »