Method for efficiently enriching platinum group metals by using copper trapping waste automobile exhaust catalyst

Abstract

The invention belongs to the technical field of solid waste resource recovery and metallurgy, and particularly relates to a method for efficiently enriching platinum group metals by using a copper trapping waste automobile exhaust catalyst, which comprises the following steps of: completely mixing a mixture of a waste catalyst, a collecting agent, a proper amount of slag former and a reducing agent in a mixer; then, putting the mixed material into a crucible, and putting the crucible into a medium-frequency induction furnace or an electric arc furnace; the furnace is heated to a given temperature and maintained for a period of time. After smelting, Cu-PGMs alloy, flue gas and slag are obtained, and the PGMs can be enriched by 10-25 times through the method.

Description

Technical Field

[0001] The invention belongs to the technical field of solid waste resource recovery and metallurgy, and specifically relates to a method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalysts. Background Art

[0002] Platinum group metals have many unique physical and chemical properties such as strong chemical stability, high catalytic properties, excellent electrical and thermal conductivity, etc. They are widely used in automobile exhaust purification, industrial catalysis, aerospace, atomic energy and environmental protection industries. Although they are not used in large quantities in these fields, they play a key role and are known as "industrial vitamins". The distribution of platinum group metal mineral resources is extremely unbalanced, and natural resources have disadvantages such as high mining difficulty and low grade. The global supply and source of platinum, palladium and rhodium in 2023. Including 228 tons of platinum, 305 tons of palladium, and 33.3 tons of rhodium, on the surface, the supply of platinum group metals meets the demand, but 132.6 tons of platinum group metals are recycled, that is, platinum group metals mined in nature can only meet 3 / 4 of the demand. Obviously, many regions around the world are facing serious risks in the supply of platinum group metals. The recycling of platinum group metals is becoming more and more important, as the production of automobile catalytic converters consumes more than 60% of PGMS usage for controlling automobile exhaust emissions. In addition, since waste catalysts usually contain coke, vanadium, nickel and other heavy metals, which may cause ground and water pollution and affect animal and plant life, they are classified as hazardous wastes and their disposal in landfills is restricted. Obviously, from the perspective of economy and environmental protection, the recovery of PGMS from waste catalysts is of great significance.

[0003] The recovery of platinum group metals is mainly carried out through two methods: wet process and pyrometallurgical process. The wet process uses acid and alkali solution to leach precious metals, and then concentrates them through precipitation and solvent extraction. Although the energy consumption is low, there are problems such as environmental pollution, high temperature and high pressure, and the use of expensive reagents. The pyrometallurgical process uses copper, nickel, lead, iron, etc. as collectors through high-temperature reactions to form alloys of platinum group metals and separate volatiles and slag. It has high efficiency and low environmental impact. Large companies such as Umicore, Johnson Matthey, Heraeus, Tanaka, etc. use pyrometallurgical enrichment technology to mix waste catalysts with slag-making agents and collectors to separate and enrich PGMs at high temperatures. Copper capture is more environmentally friendly than lead capture. The copper capture method for recovering PGMs from waste automobile exhaust catalysts has attracted widespread attention from researchers at home and abroad.

[0004] In summary, the main problems of the current technology of using copper to capture and recover PGMs in waste automobile exhaust catalysts are low PGMs capture efficiency, long smelting time and high energy consumption, poor slag fluidity, difficulty in slag-gold separation, and the PGMs concentration in the alloy needs to be improved. Therefore, it is necessary to establish a new technology for efficiently recovering PGMs from waste automobile exhaust catalysts. Summary of the invention

[0005] In view of the problems in the prior art, the present invention provides a method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst, so as to solve the problems of high smelting temperature, poor slag fluidity, difficulty in slag-gold separation, high energy consumption caused by long heat preservation and standing time, and easy loss of platinum group metals with flue gas in the existing pyrometallurgical smelting copper capture process.

[0006] Most of the platinum group metal elements in the waste catalyst exist in the form of metal oxides. Combined with the thermodynamic properties of platinum group metal oxides that are easily reduced, a new concept is proposed to achieve the reduction of platinum group metal oxides by using a reducing atmosphere to achieve efficient capture. Based on this idea, the present invention uses copper and copper compounds to capture platinum group metals, and through the reducing atmosphere and controlling the slag composition, it is beneficial to improve the capture rate of platinum group metals.

[0007] The technical solution of the present invention is:

[0008] A method for efficiently enriching platinum group metals by using a copper capture catalyst for waste automobile exhaust, comprising the following steps:

[0009] Step (1): using copper element or copper compound as a collector, mixing the collector, waste catalyst, reducing agent and slag-forming agent to obtain a mixed batch;

[0010] Step (2): Place the mixed ingredients obtained in step (1) in a medium frequency induction furnace or an arc furnace for smelting to obtain a Cu-PGMSs alloy, flue gas and slag; the Cu-PGMSs alloy is smelted by fire method to obtain platinum group metals. Electrolyze the platinum group metals to obtain anode mud or separate and purify after melting. The anode copper obtained by electrolysis can be used as a collector for copper capture, thereby realizing the resource utilization of copper.

[0011] In the above-mentioned method of efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalysts, preferably, the amount of the collector added in step (1) is 0.1-0.5 times the mass of the waste catalyst, the copper compound includes one or more of copper oxide, cuprous oxide, and copper carbonate, and the mass of the copper element is 0.08-0.14 times the mass of the waste automobile three-way exhaust catalyst. The reason why the metallic copper element has a strong ability to capture platinum group metals is that the lattice structure of metallic copper and platinum group metals is similar, and a wide concentration range of Cu-Pt, Cu-Pd, and Cu-Rh solid solutions can be formed at high temperatures. If the amount of copper is too little, the contact area between copper and platinum group metals is too small, and the capture rate of platinum group metals is low; if the amount of copper is too much, the subsequent process needs to separate copper from platinum group metals, which increases the cost of impurity removal in the subsequent process. Controlling the above ratio can better balance various factors. More preferably, the amount of cupric oxide, cuprous oxide, and cupric carbonate collector added is 0.25-0.4 times the mass of the waste catalyst, and the mass of the copper element is 0.1-0.14 times the mass of the waste catalyst. Further preferably, the mass of the copper element is 0.12 times the mass of the waste catalyst.

[0012] The above-mentioned method for efficiently enriching platinum group metals by copper capture of waste automobile exhaust catalysts, preferably, the waste catalyst in step (1) refers to a waste automobile ternary exhaust purification catalyst, the waste catalyst is supported by cordierite, and the waste catalyst contains 310g / t of platinum, 2410g / t of palladium, and 320g / t of rhodium.

[0013] In the above-mentioned method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst, preferably, the amount of the reducing agent in step (1) is 10%-50% of the catalyst raw material. The reducing agent forms a strong reducing atmosphere in the furnace, and by controlling the temperature, SiO2 is not reduced, and Si does not enter the copper to affect the subsequent wet separation and purification of platinum group metals.

[0014] In the above-mentioned method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst, the slag-forming agent in step (1) preferably comprises one or more of CaO, SiO2, Al2O3, and MgO. The addition of the slag-forming agent must strictly control the composition of the slag, and the amount and type of the slag-forming agent added must be adjusted according to the requirements of the slag.

[0015] The above-mentioned method of efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalysts, preferably, during the smelting of step (2), the mixed material is placed in a graphite crucible and then placed in a medium frequency induction furnace or an electric arc furnace. The reason why the graphite crucible is preferably used in a medium frequency induction furnace is that it is easier to form a reducing atmosphere in the furnace, which is conducive to the reduction of trace platinum group metal oxides in the catalyst, ensuring that the platinum group metals are in full contact with copper in a metallic state, and improving the capture rate. During smelting, the temperature is controlled to be 1300-1500°C and the time is 0.5-2h. Too low a smelting temperature will lead to a decrease in the capture rate, and too high a smelting temperature will shorten the life of the furnace lining. Too short a smelting time will result in a large amount of platinum group metals remaining in the slag during slag discharge, affecting the capture rate. Too long a smelting time is equivalent to a reduction in the amount of catalyst processed per unit time, increasing the recovery and collection cost.

[0016] The above-mentioned method for efficiently enriching platinum group metals by copper capture of waste automobile exhaust catalyst, preferably, the slag obtained in step (2) comprises CaO, SiO2, Al2O3 and MgO, CaO-SiO2-Al2O 3- The mass proportion of CaO in MgO is 4-40%, the mass proportion of SiO2 is 30-50%, the mass proportion of Al2O3 is 15-30%, and the mass proportion of MgO is 7-10%. In addition to the four main components, the slag also contains substances such as Fe2O3 and ZrO2. The determination of the above slag can obtain a slag with a low melting point and low viscosity, which is conducive to the efficient capture of platinum group metals and the slag discharge. The present invention innovatively adopts CaO-SiO2-Al2O 3- The quaternary slag system with MgO as the main component can reduce the melting point and viscosity of the slag by controlling the proportion of each component and adjusting the ratio of Al2O3 and MgO, and can extend the service life of the lining and reduce the cost of use without adding sand, fluoride and other slag-making agents that are seriously corrosive to the lining. More preferably, according to some metallurgical experience, the mass proportion of MgO is fixed as CaO-SiO2-Al2O 3- 7-10% of the total mass of MgO. Preferably, the mass ratio of MgO is CaO-SiO2-Al2O 3- MgO accounts for 8% of the total mass.

[0017] The above-mentioned method for efficiently enriching platinum group metals by copper capture of waste automobile exhaust catalyst is preferably such that the CaO / SiO2 ratio of the slag after smelting is 0.18-1.2.

[0018] Advantages and beneficial effects of the present invention:

[0019] 1. Compared with the prior art, the capture and recovery process in the prior art is mainly based on the iron capture process, while the present invention directly captures platinum group metals through copper and copper compounds using a carbon reduction method to achieve efficient enrichment of platinum group metals;

[0020] 2. The present invention solves the problems of high smelting temperature, poor slag fluidity, difficulty in slag-gold separation, high energy consumption caused by long insulation and standing time, and easy loss of platinum group metals with flue gas in the existing pyrometallurgical copper capture process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0022] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings and preferred embodiments of the specification. The following embodiments are used to illustrate the present invention but cannot be used to limit the scope of the present invention.

[0023] In the following examples, the recovery rates of platinum, palladium and rhodium (taking Pt as an example) are calculated using the following formula (1) (the same below):

[0024]

[0025] m g is the mass of glass slag, g;

[0026] C Pt is the content of Pt in glass slag, g / t;

[0027] m r is the mass of spent catalyst, g;

[0028] is the Pt content in the spent catalyst, g / t.

[0029] Example 1.

[0030] like Figure 1 As shown, this embodiment provides a method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst, comprising the following steps:

[0031] 100g of waste automobile exhaust purification catalyst is used as raw material, and its main chemical components are Al2O3 34.86%, SiO2 35.89%, MgO 8.79%, CaO 0.26%, platinum 310g / t, palladium 2140g / t, and rhodium 320g / t. The collector copper powder, waste catalyst and slag-making agent are mixed and prepared; the mixture is smelted at 1450℃ in a medium frequency induction furnace using a graphite crucible in a weak reducing atmosphere for 1.5h to obtain a platinum-rich metal alloy. The amount of collector copper powder is 12g, the amount of carbon powder is 3g, and the MgO in the slag accounts for 3.3% of CaO-SiO2-Al2O 3-8% of the four main components of MgO; in the CaO-Al2O3-SiO2 ternary slag system, the contents of CaO, SiO2 and Al2O3 are 32% CaO, 40% SiO2 and 20% Al2O3 respectively. Among them, the amount of SiO2 added is 33.83g, the amount of MgO added is 5.15g, and the amount of CaO added is 55.78g. After waiting for the separation of slag and gold, 11.95g of copper alloy and 173g of smelting slag are obtained. The contents of platinum, palladium and rhodium in the slag are 1.25g / t, 10.76g / t and 2.74g / t respectively.

[0032] In this embodiment, it is calculated that the recovery rates of platinum, palladium and rhodium are 99.30%, 99.13% and 98.52% respectively.

[0033] Example 2.

[0034] like Figure 1 As shown, this embodiment provides a method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst, comprising the following steps:

[0035] 100g of waste automobile exhaust purification catalyst is used as raw material, and its main chemical components are Al2O3 34.86%, SiO2 35.89%, MgO 8.79%, CaO 0.26%, platinum 310g / t, palladium 2140g / t, and rhodium 320g / t. Copper oxide, waste catalyst, carbon powder and slag-making agent are mixed and prepared; the mixture is smelted at 1500℃ in a medium frequency induction furnace using a graphite crucible in a weak reducing atmosphere for 1.5h to obtain a platinum-rich metal alloy. The amount of copper oxide is 40g, the amount of carbon powder is 5g, and the MgO in the slag accounts for 3.3% of CaO-SiO2-Al2O 3- MgO accounts for 7% of the four main components; in the CaO-Al2O3-SiO2 ternary slag system, the contents of CaO, SiO2 and Al2O3 are 35.45% CaO, 42.55% SiO2 and 15% Al2O3 respectively, of which the amount of SiO2 added is 63g, the amount of MgO added is 7.48g, and the amount of CaO added is 82.39g. After the slag and gold are separated, 27.7g of copper alloy is obtained. The contents of platinum, palladium and rhodium in 230g slag are 1.31g / t, 8.40g / t and 2.21g / t respectively.

[0036] In this embodiment, it is calculated that the recovery rates of platinum, palladium and rhodium are 99.02%, 99.09% and 98.41% respectively.

[0037] Example 3.

[0038] like Figure 1 As shown, this embodiment provides a method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst, comprising the following steps:

[0039] 100g of waste automobile exhaust purification catalyst is used as raw material, and its main chemical components are Al2O3 34.86%, SiO2 35.89%, MgO 8.79%, CaO 0.26%, platinum 310g / t, palladium 2140g / t, and rhodium 320g / t. Cuprous oxide, waste catalyst, carbon powder and slag-making agent are mixed and prepared; the mixture is smelted at 1400℃ in a medium frequency induction furnace using a graphite crucible in a weak reducing atmosphere for 2h to obtain a platinum-rich metal alloy. The amount of cuprous oxide is 40g, the amount of carbon powder is 4g, and the MgO in the slag accounts for 3.3% of CaO-SiO2-Al2O 3- MgO is 9% of the four main components; in the CaO-Al2O3-SiO2 ternary slag system, the contents of CaO, SiO2 and Al2O3 are 31.56% CaO, 34.44% SiO2 and 25% Al2O3 respectively. Among them, the amount of SiO2 added is 12.13g, the amount of MgO added is 3.76g, and the amount of CaO added is 44.01g. After waiting for the separation of slag and gold, 35.16g copper alloy and 138g smelting slag are obtained. The contents of platinum, palladium and rhodium in the slag are 1.99g / t, 15.35g / t and 4.57g / t respectively.

[0040] In this embodiment, it is calculated that the recovery rates of platinum, palladium and rhodium are 99.11%, 99.01% and 98.03% respectively.

[0041] Example 4.

[0042] like Figure 1 As shown, this embodiment provides a method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst, comprising the following steps:

[0043] 100g of waste automobile exhaust purification catalyst is used as raw material, and its main chemical components are Al2O3 34.86%, SiO2 35.89%, MgO 8.79%, CaO 0.26%, platinum 310g / t, palladium 2140g / t, and rhodium 320g / t. Cuprous oxide, waste catalyst, carbon powder and slag-making agent are mixed and prepared; the mixture is smelted at 1500℃ in a medium frequency induction furnace using a graphite crucible in a weak reducing atmosphere for 1.5h to obtain a platinum-rich metal alloy. The amount of cuprous oxide is 35g, the amount of carbon powder is 4g, and the MgO in the slag accounts for 3.3% of CaO-SiO2-Al2O 3-7% of the four main components of MgO; in the CaO-Al2O3-SiO2 ternary slag system, the contents of CaO, SiO2 and Al2O3 are 30.06% CaO, 42.97% SiO2 and 20% Al2O3 respectively. Among them, the amount of SiO2 added is 42.97g, the amount of MgO added is 3.41g, and the amount of CaO added is 52.39g. After waiting for the separation of slag and gold, 29.86g of copper alloy and 172.3g of smelting slag are obtained. The contents of platinum, palladium and rhodium in the slag are 3.18g / t, 17.88g / t and 5.53g / t respectively.

[0044] In this embodiment, it is calculated that the recovery rates of platinum, palladium and rhodium are 98.23%, 98.56% and 97.01% respectively.

[0045] Example 5.

[0046] like Figure 1 As shown, this embodiment provides a method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst, comprising the following steps:

[0047] 100g of waste automobile exhaust purification catalyst is used as raw material, and its main chemical components are Al2O3 34.86%, SiO2 35.89%, MgO 8.79%, CaO 0.26%, platinum 310g / t, palladium 2140g / t, and rhodium 320g / t. Copper carbonate, waste catalyst, carbon powder and slag-making agent are mixed and prepared; the mixture is smelted at 1500℃ in a medium frequency induction furnace using a graphite crucible in a weak reducing atmosphere for 1.5h to obtain a platinum-rich metal alloy. The amount of copper carbonate is 45g, the amount of carbon powder is 7g, and the MgO in the slag accounts for 3.3% of CaO-SiO2-Al2O 3- 10% of the four main components of MgO; in the CaO-Al2O3-SiO2 ternary slag system, the contents of CaO, SiO2 and Al2O3 are 35.53% CaO, 39.47% SiO2 and 15% Al2O3 respectively. Among them, the amount of SiO2 added is 55.84g, the amount of MgO added is 14.45g, and the amount of CaO added is 82.57g. After waiting for the separation of slag and gold, 12.71g of copper alloy and 230.01g of smelting slag are obtained. The contents of platinum, palladium and rhodium in the slag are 2.07g / t, 7.54g / t and 4.97g / t respectively.

[0048] In this embodiment, it is calculated that the recovery rates of platinum, palladium and rhodium are 98.46%, 99.19% and 96.43% respectively.

[0049] Example 6

[0050] like Figure 1 As shown, this embodiment provides a method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst, comprising the following steps:

[0051] 100g of waste automobile exhaust purification catalyst is used as raw material, and its main chemical components are Al2O3 34.86%, SiO2 35.89%, MgO 8.79%, CaO 0.26%, platinum 310g / t, palladium 2140g / t, and rhodium 320g / t. Copper carbonate, waste catalyst, carbon powder and slag-making agent are mixed and prepared; the mixture is smelted at 1450℃ in a medium frequency induction furnace using a graphite crucible in a weak reducing atmosphere for 2h to obtain a platinum-rich metal alloy. The amount of copper carbonate is 35g, the amount of carbon powder is 8g, and the MgO in the slag accounts for 3.3% of CaO-SiO2-Al2O 3- MgO accounts for 7% of the four main components; in the CaO-Al2O3-SiO2 ternary slag system, the contents of CaO, SiO2 and Al2O3 are 32.45% CaO, 40.55% SiO2 and 20% Al2O3 respectively, of which the amount of SiO2 added is 37.79g, the amount of MgO added is 3.41g, and the amount of CaO added is 56.56g. After waiting for the slag and gold to be separated, 17.86g of copper alloy and 172.1g of smelting slag are obtained. The contents of platinum, palladium and rhodium in the slag are 4.77g / t, 23.37g / t and 9.06g / t respectively.

[0052] In this embodiment, it is calculated that the recovery rates of platinum, palladium and rhodium are 97.35%, 98.12% and 95.14% respectively.

[0053] Example 7.

[0054] like Figure 1 As shown, this embodiment provides a method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst, comprising the following steps:

[0055] 1kg of waste automobile exhaust purification catalyst is used as raw material, and its main chemical components are Al2O3 34.86%, SiO2 35.89%, MgO 8.79%, CaO 0.26%, platinum 310g / t, palladium 2140g / t, and rhodium 320g / t. Copper oxide, waste catalyst, and slag-making agent are mixed and prepared; the mixture is smelted at 1500℃ in a medium frequency induction furnace using a graphite crucible in a weak reducing atmosphere for 2 hours to obtain a platinum-rich metal alloy. The amount of copper oxide is 450g, the amount of carbon powder is 40g, and the MgO in the slag accounts for 1.3% of CaO-SiO2-Al2O 3-MgO accounts for 9% of the four main components; in the CaO-Al2O3-SiO2 ternary slag system, the contents of CaO, SiO2 and Al2O3 are 38% CaO, 38% SiO2 and 15% Al2O3 respectively, of which the amount of SiO2 added is 524.2g, the amount of MgO added is 121.3g, and the amount of CaO added is 883.1g. After waiting for the slag and gold to be separated, 316.48g of copper alloy and 2304g of smelting slag are obtained. The contents of platinum, palladium and rhodium in the slag are 1.04g / t, 5.95g / t and 1.77g / t respectively.

[0056] In this embodiment, it is calculated that the recovery rates of platinum, palladium and rhodium are 99.23%, 99.36% and 98.72% respectively.

[0057] Example 8

[0058] like Figure 1 As shown, this embodiment provides a method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst, comprising the following steps:

[0059] 1kg of waste automobile exhaust purification catalyst is used as raw material, and its main chemical components are Al2O3 34.86%, SiO2 35.89%, MgO 8.79%, CaO 0.26%, platinum 310g / t, palladium 2140g / t, and rhodium 320g / t. Copper, waste catalyst, carbon powder and slag-making agent are mixed and prepared; the mixture is smelted in a medium frequency induction furnace using a graphite crucible at 1450℃ under a reducing atmosphere for 1.5h to obtain a platinum-rich metal alloy. The amount of copper is 140g, the carbon powder is 20g, and the MgO in the slag accounts for 3.3% of the CaO-SiO2-Al2O 3- 10% of the four main components of MgO; in the CaO-Al2O3-SiO2 ternary slag system, the contents of CaO, SiO2 and Al2O3 are 26.76% CaO, 38.24% SiO2 and 25% Al2O3 respectively. Among them, the amount of SiO2 added is 174.3g, the amount of MgO added is 51.5g, and the amount of CaO added is 373.1g. After waiting for the separation of slag and gold, 139.3g copper alloy and 1380.4g smelting slag are obtained. The contents of platinum, palladium and rhodium in the slag are 2.17g / t, 9.92g / t and 2.96g / t respectively.

[0060] In this embodiment, it is calculated that the recovery rates of platinum, palladium and rhodium are 99.03%, 99.36% and 98.72% respectively.

[0061] Example 9.

[0062] like Figure 1 As shown, this embodiment provides a method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst, comprising the following steps:

[0063] 20kg of waste automobile exhaust purification catalyst is used as raw material, and its main chemical components are Al2O3 34.86%, SiO2 35.89%, MgO 8.79%, CaO 0.26%, platinum 310g / t, palladium 2140g / t, and rhodium 320g / t. Copper, waste catalyst, carbon powder and slag-making agent are mixed and prepared; the mixture is smelted in a medium frequency induction furnace using a graphite crucible at 1500℃ under a reducing atmosphere for 2h to obtain a platinum-rich metal alloy. The amount of copper is 2400g, the carbon powder is 800g, and the MgO in the slag accounts for 3.3% of CaO-SiO2-Al2O 3- 8% of the four main components of MgO; in the CaO-Al2O3-SiO2 ternary slag system, the contents of CaO, SiO2 and Al2O3 are 32% CaO, 40% SiO2 and 20% Al2O3 respectively. Among them, the amount of SiO2 added is 6766g, the amount of MgO added is 1030g, and the amount of CaO added is 11156g. After waiting for the separation of slag and gold, 2386g of copper alloy and 34060g of smelting slag are obtained. The contents of platinum, palladium and rhodium in the slag are 1.09g / t, 6.03g / t and 2.27g / t respectively.

[0064] In this embodiment, it is calculated that the recovery rates of platinum, palladium and rhodium are 99.40%, 99.52% and 98.79% respectively.

Claims

1. A method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalysts, characterized in that: The following steps are involved: Step (1): using copper element or copper compound as a collector, mixing the collector, waste catalyst, reducing agent and slag-forming agent to obtain a mixed batch; Step (2): placing the mixed ingredients obtained in step (1) in a medium frequency induction furnace or an electric arc furnace for smelting to obtain a Cu-PGMSs alloy, flue gas and slag; the Cu-PGMSs alloy is pyrometallurgically smelted to obtain platinum group metals.

2. The method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst according to claim 1, characterized in that: The amount of the collector added in step (1) is 0.1-0.5 times the mass of the waste catalyst, and the copper compound includes one or more of cupric oxide, cuprous oxide, and cupric carbonate.

3. The method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst according to claim 1, characterized in that: The waste catalyst in step (1) is supported by cordierite, and contains 310 g / t of platinum, 2410 g / t of palladium, and 320 g / t of rhodium.

4. The method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst according to claim 1, characterized in that: The amount of the reducing agent in step (1) is 3%-20% of the catalyst raw material.

5. The method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst according to claim 1, characterized in that: The slag-forming agent in step (1) includes one or more of CaO, SiO2, Al2O3, and MgO.

6. The method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst according to claim 1, characterized in that: During the smelting in step (2), the temperature is controlled to be 1300-1500° C. and the time is 0.5-2 h.

7. The method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst according to claim 1, characterized in that: The slag obtained in step (2) includes CaO, SiO2, Al2O3 and MgO. 3- The mass proportion of CaO in MgO is 4-40%, the mass proportion of SiO2 is 30-50%, the mass proportion of Al2O3 is 15-30%, and the mass proportion of MgO is 7-10%.

8. The method for efficiently enriching platinum group metals by using copper to capture waste automobile exhaust catalyst according to claim 7, characterized in that: The CaO / SiO2 ratio is 0.18-1.2.

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