Method for enriching valuable precious metal from scrap copper

Abstract

The invention discloses a method for enriching valuable noble metals from scrap copper, which comprises the following steps: placing scrap copper on a material conveyor belt, and separating high-value metals and mixed copper alloy materials in a manual assembly line manner; high-value metal is subjected to physical treatment, that is, mechanical crushing is conducted firstly, then wind power specific gravity separation is utilized, first crushed ash is obtained through dust collection, the remaining material is a first crushed material, and the first crushed ash is a first precious metal enrichment; physical treatment is conducted on the mixed copper alloy material, namely mechanical crushing is conducted firstly, then wind power specific gravity separation is conducted, second crushed ash is obtained through dust collection, the remaining material is a second crushed material, and the second crushed ash is a second precious metal enriched product; and the second crushed material is subjected to pyrogenic process smelting to form a melt, a slag removal agent is added into the melt for slag removal, the slag is dredged, and obtained slag is a third precious metal enrichment. According to the method, the high recovery rate of the valuable precious metal in the scrap copper can be guaranteed, the technological process can be greatly optimized, and energy consumption and use of chemical reagents are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of precious metal recovery, and in particular relates to a method for enriching valuable precious metals from scrap copper. Background Art

[0002] Recovering precious metals from copper scrap is a crucial step in resource recycling, with significant economic value and environmental significance. With the rapid development of the electronics industry, the generation of copper-containing waste materials, such as electronic waste, scrap cables, and industrial waste, has increased year by year. These waste materials not only contain large amounts of copper, but are also rich in valuable precious metals such as gold, silver, platinum, and palladium. Due to their unique physical and chemical properties, precious metals play an irreplaceable role in fields such as electronics, chemicals, jewelry, medicine, and the automotive industry. However, the content of precious metals in copper scrap is typically low, and they are mixed with other metal and non-metal components, making recovery difficult. Therefore, the development of efficient, environmentally friendly, and economical precious metal recovery technologies has become a research hotspot in the current field of resource recovery.

[0003] At present, the main technologies for recovering precious metals from scrap copper include pyrometallurgy and hydrometallurgy, which are widely used in industrial production. Although pyrometallurgy and hydrometallurgy have been widely used in the field of precious metal recovery, they still face many challenges in practical application: (1) Low efficiency of low-content precious metal recovery: The precious metal content in scrap copper is usually low, and existing methods are difficult to recover efficiently. Some precious metals are lost during the process, resulting in resource waste; (2) Environmental pollution: The high-temperature smelting process of pyrometallurgy produces a large amount of harmful gases and solid waste, and improper treatment of chemical waste liquid from hydrometallurgy can also cause environmental pollution; (3) Insufficient economic efficiency: The high energy consumption of pyrometallurgy and the high reagent cost of hydrometallurgy lead to poor economic efficiency of precious metal recovery, which is difficult to meet the needs of industrial large-scale production; (4) Process complexity: Existing methods usually require multiple steps, complex processes, large equipment investment, and high operational difficulty. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for enriching valuable precious metals from scrap copper in view of the shortcomings of the existing technology. The method can not only ensure a high recovery rate of valuable precious metals in scrap copper, but also significantly optimize the process flow and reduce energy consumption and the use of chemical reagents.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a method for enriching valuable precious metals from scrap copper, comprising the following steps:

[0006] S1. Place scrap copper on a material conveyor belt and manually sort high-value metals and mixed copper alloy materials in an assembly line according to the national standards "GB / T 38471-2023 Recycled Copper Raw Materials" and "GB / T 13587-2020 Copper and Copper Alloy Waste";

[0007] S2. Physically treating the high-value metals, i.e., first mechanically crushing the metals, then using wind-force gravity separation, obtaining crushed ash 1 by vacuuming, and the remaining material being crushed material 1, wherein the crushed ash 1 is a precious metal concentrate 1;

[0008] S3, physically treating the mixed copper alloy material, i.e., first mechanically crushing it, then using wind-force specific gravity sorting, obtaining crushed ash II by vacuuming, and the remaining material being crushed material II, wherein the crushed ash II is precious metal-enriched material II;

[0009] S4. The crushed material 2 is subjected to fire smelting to obtain a melt, a slag cleaning agent is added to the melt to remove the slag, and the slag is collected. The obtained slag is the precious metal enriched product 3.

[0010] Preferably, the high-value metals are gold / silver plating materials, gold / silver welding materials, and gold / silver contact materials, as categorized in accordance with the national standard "GB / T 38471-2023 Recycled Copper Raw Materials." Plating materials, such as copper alloy ornaments, crafts, and high-end bathroom faucets, are plated with gold or silver to enhance their luster. Welding materials, such as copper alloy pipes and copper tubes and rods, utilize gold or silver welding to ensure tight joints. Contact materials, such as electrical plugs or contacts, utilize gold or silver filling to enhance conductivity.

[0011] Preferably, the mixed copper alloy material is various brass alloy tubes, rods, joints, bronze, white copper parts, and red copper wires, tubes, and rods classified according to the national standard "GB / T 13587-2020 Copper and Copper Alloy Waste".

[0012] Preferably, the particle sizes of the crushed ash 1 and the crushed ash 2 are 20-120 meshes respectively, the diameters of the crushed material 1 and the crushed material 2 are 5-80 mm respectively, and the particle size of the slag is 50-160 meshes.

[0013] As a further preference, the mechanical crushing is carried out on a mechanical crusher, and the mechanical crushing tools on the mechanical crusher include a fixed knife and a movable knife. The gap between the fixed knife and the movable knife is 1.5 to 2.0 times the maximum diameter of the crushed material one and the crushed material two. The adjustable range of the gap between the fixed knife and the movable knife is 0.5 to 5 mm to ensure that after mechanical crushing, the diameters of the crushed material one and the crushed material two are 5 to 80 mm respectively.

[0014] Preferably, the pyrometallurgical smelting is carried out in an industrial frequency cored electric furnace, and the maximum temperature of the pyrometallurgical smelting is 1100-1200°C.

[0015] Preferably, the slag cleaning agent consists of borax, calcium fluoride, sodium carbonate, ammonium chloride, carbon powder and calcium carbonate.

[0016] As a further preference, the slag cleaning agent comprises by weight: 10-15% borax, 40-50% calcium fluoride, 10-15% sodium carbonate, 10-15% ammonium chloride, 5-10% carbon powder and 5-10% calcium carbonate.

[0017] Compared with the existing technology, the present invention has the following advantages: the present invention proposes an innovative precious metal recovery process, which can enrich valuable precious metals from scrap copper through assembly line sorting, mechanical crushing, wind specific gravity sorting, and pyrometallurgical smelting technology, thereby achieving efficient, environmentally friendly and economical precious metal enrichment, which can not only ensure a high recovery rate of valuable precious metals in scrap copper, but also greatly optimize the process flow and reduce energy consumption and the use of chemical reagents. The method of the present invention for enriching valuable precious metals from scrap copper has a recovery rate of more than 96.8% for the valuable precious metals in the scrap copper (i.e., more than 96.8% of the total amount of the valuable precious metals in the scrap copper is enriched into the first, second and third precious metal enrichments). In addition, the recovered first, second and third precious metal enrichments have an elemental gold (Au) content of approximately 20 to 100 g / t, an elemental silver (Ag) content of approximately 300 to 800 g / t, and a total platinum group metal (Ru, Rh, Pd, Os, Ir, Pt) content of approximately 0.4 to 1.0 g / t. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 4 is a process flow chart of the method of the present invention. DETAILED DESCRIPTION

[0019] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments. Any equipment or process not specified in the present invention is conventional in the art.

[0020] The method for enriching valuable precious metals from scrap copper of the embodiment, such as Figure 1 As shown, the following steps are included:

[0021] S1. Place scrap copper on a material conveyor belt and manually sort high-value metals and mixed copper alloy materials in an assembly line according to the national standards "GB / T 38471-2023 Recycled Copper Raw Materials" and "GB / T 13587-2020 Copper and Copper Alloy Waste". High-value metals include gold / silver materials for plating, gold / silver materials for welding, and gold / silver materials for contacts, as classified in accordance with the national standard "GB / T 38471-2023 Recycled Copper Raw Materials". Mixed copper alloy materials include various brass alloy tubes, rods, joints, bronze and white copper components, and red copper wires, tubes, and rods, as classified in accordance with the national standard "GB / T 13587-2020 Copper and Copper Alloy Waste".

[0022] S2. Physically process the high-value metals, i.e., first mechanically crush them, then use wind-driven gravity separation, obtain crushed ash 1 through dust collection, and the remaining material is crushed material 1. The crushed ash 1 is a precious metal concentrate 1, and the particle size of the crushed ash 1 is 20-120 mesh. The diameter of the crushed material 1 is 5-80 mm. The crushed material 1 can be sent to smelting equipment or a smelter for further processing;

[0023] S3. Physically treating the mixed copper alloy material, i.e., first mechanically crushing it, then using wind gravity separation, obtaining crushed ash II by vacuuming, and the remaining material is crushed material II, wherein the crushed ash II is precious metal enriched material II, the particle size of the crushed ash II is 20-120 mesh, and the diameter of the crushed material II is 5-80 mm;

[0024] S4. The crushed material No. 2 is subjected to fire smelting in an industrial frequency cored electric furnace to form a melt. The maximum temperature of the fire smelting is 1200°C. A slag cleaning agent is added to the melt to clean the slag. The slag is then scooped out with a slag scoop. The resulting slag is the precious metal enriched product No. 3. The particle size of the slag is 50-160 mesh.

[0025] In the above steps S2 and S3, mechanical crushing is performed on a mechanical crusher respectively. The mechanical crushing tools on the mechanical crusher include a fixed knife and a movable knife. The gap between the fixed knife and the movable knife is 1.5 to 2.0 times the maximum diameter of the crushed material one and the crushed material two. The adjustable range of the gap between the fixed knife and the movable knife is 0.5 to 5 mm.

[0026] The slag cleaning agent used in the above step S4 is composed of borax, calcium fluoride, sodium carbonate, ammonium chloride, carbon powder and calcium carbonate, and its mass percentage composition is: borax 15%, calcium fluoride 45%, sodium carbonate 10%, ammonium chloride 15%, carbon powder 5% and calcium carbonate 10%.

[0027] Testing has shown that the above-mentioned method for enriching valuable precious metals from scrap copper achieves a recovery rate of over 96.8% for valuable precious metals in the scrap copper (i.e., over 96.8% of the total amount of valuable precious metals in the scrap copper is enriched in the first, second, and third precious metal enrichment products). Furthermore, the recovered first, second, and third precious metal enrichment products contain approximately 20 to 100 g / t of gold (Au), approximately 300 to 800 g / t of silver (Ag), and approximately 0.4 to 1.0 g / t of platinum group metals (Ru, Rh, Pd, Os, Ir, and Pt). This method can enrich valuable precious metals from scrap copper, achieving efficient, environmentally friendly, and economical precious metal enrichment. It not only ensures a high recovery rate for valuable precious metals in the scrap copper, but also significantly optimizes the process flow, reducing energy consumption and the use of chemical reagents.

Claims

1. A method for enriching precious metals from scrap copper, characterized in that: The following steps are involved: S1. Place scrap copper on a material conveyor belt and manually sort high-value metals and mixed copper alloy materials in an assembly line according to the national standards "GB / T 38471-2023 Recycled Copper Raw Materials" and "GB / T 13587-2020 Copper and Copper Alloy Waste"; S2. Physically treating the high-value metals, i.e., first mechanically crushing the metals, then using wind-force gravity separation, obtaining crushed ash 1 by vacuuming, and the remaining material being crushed material 1, wherein the crushed ash 1 is a precious metal concentrate 1; S3, physically treating the mixed copper alloy material, i.e., first mechanically crushing it, then using wind-force specific gravity sorting, obtaining crushed ash II by vacuuming, and the remaining material being crushed material II, wherein the crushed ash II is precious metal-enriched material II; S4. The crushed material 2 is subjected to fire smelting to obtain a melt, a slag cleaning agent is added to the melt to remove the slag, and the slag is collected. The obtained slag is the precious metal enriched product 3.

2. The method for enriching precious metals from scrap copper according to claim 1, characterized in that: The high-value metals are gold / silver materials for plating, gold / silver materials for welding and gold / silver materials for contacts classified according to the national standard GB / T 38471-2023 Recycled Copper Raw Materials.

3. The method for enriching precious metals from scrap copper according to claim 1, characterized in that: The mixed copper alloy materials are various brass alloy tubes, rods, joints, bronze, white copper parts, and red copper wires, tubes, and rods classified according to the national standard "GB / T 13587-2020 Copper and Copper Alloy Waste".

4. The method for enriching precious metals from scrap copper according to claim 1, characterized in that: The particle sizes of the crushed ash 1 and the crushed ash 2 are 20-120 meshes respectively, the diameters of the crushed material 1 and the crushed material 2 are 5-80 mm respectively, and the particle size of the slag is 50-160 meshes.

5. The method for enriching precious metals from scrap copper according to claim 4, characterized in that: The mechanical crushing is carried out on a mechanical crusher. The mechanical crushing tools on the mechanical crusher include a fixed knife and a movable knife. The gap between the fixed knife and the movable knife is 1.5 to 2.0 times the maximum diameter of the crushed material one and the crushed material two. The adjustable range of the gap between the fixed knife and the movable knife is 0.5 to 5 mm.

6. The method for enriching precious metals from scrap copper according to claim 1, characterized in that: The fire smelting is carried out in an industrial frequency cored electric furnace, and the maximum temperature of the fire smelting is 1100-1200°C.

7. The method for enriching precious metals from scrap copper according to claim 1, characterized in that: The slag cleaning agent consists of borax, calcium fluoride, sodium carbonate, ammonium chloride, carbon powder and calcium carbonate.

8. The method for enriching precious metals from scrap copper according to claim 7, characterized in that: The slag cleaning agent is composed of the following mass percentages: 10-15% borax, 40-50% calcium fluoride, 10-15% sodium carbonate, 10-15% ammonium chloride, 5-10% carbon powder and 5-10% calcium carbonate.

Images