Method for comprehensively recovering valuable metals by synergistically utilizing waste platinum and palladium leaching residues and copper residues
Through the coordinated use of waste platinum-palladium leaching slag and copper slag, the methods of CaO and Na2O flux and waste cathode carbon reducing agent are adopted to achieve efficient recycling of platinum, palladium, copper and iron, and the solution is to solve the problem of waste platinum-palladium leaching slag. The problem of low recovery rate of valence metals reduces costs and improves economic benefits.
Patent Information
- Application Number
- CN202411556592.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-04
- Publication Date
- 2025-02-07
AI Technical Summary
The recovery rates of platinum and palladium in waste platinum and palladium leaching slag are low, and there is a risk of environmental hazards, and there is no close industrial chain of low-cost recycling.
By synergistically using waste platinum-palladium leaching slag with copper slag, CaO and Na2O are used as flux, and waste cathode carbon is used as reducing agent, reducing and smelting is carried out under an inert carrier gas atmosphere, platinum-palladium is captured to form a Fe-based-PGMs alloy. And the valuable metal is separated and recovered by slow cooling at high temperature.
The efficient recovery rates of platinum, palladium, copper and iron in waste platinum and palladium leaching slag-copper slag were achieved, reaching 99.57%, 99.75%, 97.01% and 97.21% respectively, and environmentally friendly aluminosilicate-based microcrystals were generated. Glass, reduces costs and improves economic benefits.
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Figure CN119391993A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of resource recovery and utilization, and in particular to a method for comprehensive recovery of valuable metals by coordinated utilization of waste platinum-palladium leaching slag-copper slag. Background Art
[0002] Among the platinum group metals, platinum and palladium are the most widely used and consumed. Among them, Pt / Pd-Al2O3 catalysts are widely used in petrochemicals, fine chemicals, hydrogen peroxide industry and other fields. They have the characteristics of high catalytic efficiency, good selectivity and long life.
[0003] The recovery methods of Pt / Pd-Al2O3 waste catalysts mainly include pyrometallurgy and hydrometallurgy. Due to the short process flow, low energy consumption and cost of the hydrometallurgy, the current process for recovering platinum and palladium from waste Pt / Pd-Al2O3 catalysts is mainly based on the hydrometallurgy. There are many types of secondary resources of platinum and palladium, and the impurity content varies. It is necessary to formulate reasonable recovery processes according to the characteristics of different raw materials, including active component dissolution method, carrier dissolution method and full dissolution method. For example, in the active component dissolution method, platinum group metals are easily wrapped by carriers or carbon deposits, resulting in low leaching rates, and pretreatment is required by roasting, oxidation, reduction and other methods. Although matching leaching methods are selected for different material characteristics, the contents of Pt and Pd in the leached residue of waste Pt / Pd-Al2O3 catalysts treated by the hydrometallurgy are still 100~200 g / t and 40~80 g / t, which are still 2~10 g / t higher than the precious metal grade in the original ore. Due to the relatively low recovery value, it is currently in a state of unified sale after large-scale storage, and a close industrial chain of low-cost recovery has not been formed, which poses a risk of harming the environment.
[0004] In view of the above situation, it is necessary to study the method of comprehensive recovery of valuable metals by synergistic utilization of waste platinum and palladium leaching slag-copper slag to solve the above technical problems. Summary of the invention
[0005] The object of the present invention is to provide a method for comprehensive recovery of valuable metals by synergistic utilization of waste platinum-palladium leaching slag-copper slag, which can make the recovery rates of valuable metals such as platinum, palladium, copper and iron in the waste platinum-palladium leaching slag-copper slag as high as 99.57%, 99.75%, 97.01% and 97.21% respectively.
[0006] To achieve the above object, the present invention provides a method for comprehensive recovery of valuable metals by synergistic utilization of waste platinum and palladium leaching residues and copper slag, comprising the following steps: Grinding and sieving the waste platinum-palladium leaching slag and the copper slag respectively to obtain waste platinum-palladium leaching slag powder and copper slag powder; adding the copper slag powder to the waste platinum-palladium leaching slag powder and mixing the two evenly to obtain a mixed powder; After adding a reducing agent and a flux to the mixed powder, reduction smelting is performed for 30 to 180 min at a temperature of 1300 to 1550 °C under an inert carrier gas atmosphere until the metal oxides in the slag are reduced to form metal elements and the platinum and palladium are captured to form an Fe-based-PGMs alloy; The smelted slag is slowly cooled, the slag phase of the slag is located in the upper layer, and the alloy phase settles in the bottom layer; the slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy.
[0007] Specifically, after XRD and XRF analysis, the components in the waste platinum-palladium leaching slag are Al2O3, and the components in the copper slag are Fe2SiO4 and Fe3O4.
[0008] Preferably, the mass ratio of the waste platinum-palladium leaching residue to the copper residue in step (1) is 0.2-1.0:1.
[0009] Preferably, the amount of the reducing agent added in step (2) is 5-30% of the mass of the copper slag, and the reducing agent is waste cathode carbon.
[0010] Preferably, the flux in step (2) is CaO and Na2O, and the mass ratio of CaO to Na2O is 1:1 to 1:5.
[0011] Specifically, the amount of CaO and Na2O added is determined by the alkalinity ((CaO+Na2O) / (Al2O3+SiO2)), and the alkalinity range is 0.4~1.2.
[0012] Preferably, in step (2), before reduction smelting, the temperature is raised to 1000° C. at 7° C. / min at room temperature in a positive pressure atmosphere furnace, and then raised to 1300-1550° C. at 5° C. / min.
[0013] Preferably, the inert carrier gas atmosphere in step (2) is nitrogen or argon, with a flow rate of 50-200 mL / min.
[0014] Preferably, the sieving in step (2) is through a 50-200 mesh sieve.
[0015] (1) The present invention uses SiO2-Al2O3-CaO in the mixed slag as the basic slag system, uses CaO and Na2O as fluxes, and waste cathode carbon as a reducing agent to reduce metals such as iron and copper to capture platinum and palladium in the waste platinum-palladium leaching slag. The smelting slag is slowly cooled at high temperature to prepare environmentally friendly aluminosilicate glass-ceramics. After cooling, the alloy ingot and the slag are physically separated to recover the valuable metals platinum, palladium, copper and iron.
[0016] (2) The present invention uses copper slag, a solid waste generated during the copper smelting process, and utilizes metals such as Fe and Cu therein as collectors, and CaO, SiO2, etc. in the slag as slag-forming agents, thereby realizing the recovery of iron and copper resources in the copper slag and platinum group metals in the waste platinum and palladium leaching slag. Compared with traditional iron capture, the present invention can reduce the amount of Fe added and the amount of slag-forming agent added, thereby improving the utilization rate of secondary resources, greatly reducing costs, and improving economic benefits.
[0017] (3) The reducing agent used in the present invention is waste cathode carbon, which is a solid hazardous waste generated in the aluminum smelting process. Compared with the reducing agent (anthracite, coke) used in the traditional method, it has higher economic and environmental benefits.
[0018] (4) The present invention significantly reduces the viscosity and melting point of the slag and improves the fluidity of the slag by adding a small amount of CaO and Na2O flux. In addition, the density of this type of slag composed of SiO2, Al2O3, CaO, and Na2O is relatively small, which is significantly different from the density of the alloy, thereby enhancing the aggregation, growth, and directional capture of the molten iron liquid in the molten state, and improving the slag-gold separation effect. The recovery rates of platinum, palladium, copper, and iron in the generated Fe-based-PGMs alloy are as high as 99.57%, 99.75%, 97.01%, and 97.21%, respectively, and the contents in the microcrystalline glass slag are 0.12 g / t, 0.08 g / t, 0.02 g / t, and 1.16 g / t, respectively.
[0019] (5) The microcrystalline glass slag obtained by the present invention is an environmentally friendly aluminum-silicon microcrystalline glass, and the toxicity leaching results meet the US-EPA standards. The microcrystalline glass can be regarded as a harmless material, which realizes the high-value utilization of slag and can be widely used in the construction and decoration industry, energy, electronics industry, aerospace, optics and other fields. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a process flow chart of the present invention.
[0021] Figure 2 The XRD spectrum of the raw materials used in the present invention, wherein (a) is copper slag and (b) is waste catalyst leaching slag.
[0022] Figure 3 This is the XRD spectrum of the microcrystalline glass obtained in Example 2 of the present invention.
[0023] Figure 4 It is a bar chart showing the determination of the contents of platinum, palladium, iron and copper in the smelting slags of Examples 1, 2 and 3 of the present invention.
[0024] Figure 5 It is a bar chart of the calculated recoveries of platinum, palladium, iron and copper in Examples 1, 2 and 3 of the present invention.
[0025] Figure 6It is a bar graph of the results of the toxicity leaching experiment of the microcrystalline glass prepared in Example 2 of the present invention. DETAILED DESCRIPTION
[0026] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limitations of the present invention. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.
[0027] The XRD patterns of the waste platinum-palladium leaching residue and copper slag used in the following examples are as follows: Figure 2 As shown by Figure 2 It can be seen that the components in the waste platinum and palladium leaching slag are Al2O3, and the components in the copper slag are Fe2SiO4 and Fe3O4. Example 1
[0028] like Figure 1 As shown, the method for comprehensively recovering platinum, palladium, copper and iron by synergistic utilization of waste platinum-palladium leaching slag-copper slag comprises the following specific steps: grinding and sieving 25 g of copper slag and 25 g of waste platinum-palladium leaching slag to particle sizes of 200 and 100 mesh respectively, adding copper slag to the waste platinum-palladium leaching slag and mixing them evenly, wherein the ratio of the added amount of waste platinum-palladium leaching slag to copper slag is 1:1, and then heating to 1000°C at 7°C / min at room temperature under an inert carrier gas atmosphere (the inert carrier gas is nitrogen with a flow rate of 100 mL / min), and then heating to 1450°C at 5°C / min, reducing 180°C at a temperature of 1450°C, a basicity of 0.4, a reducing agent addition amount of 15%, and m(Na2O) / m(CaO)=1:3. min. During this process, oxides such as Fe3O4 are reduced to generate metal elements and capture platinum and palladium to form Fe-based-PGMs alloys. After the smelting slag is slowly cooled at high temperature, the slag phase of the slag is located in the upper layer and the alloy phase settles in the bottom layer. The slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy. The Fe-based-PGMs alloy contains valuable metals such as platinum, palladium, iron, and copper.
[0029] After the copper slag was reduced and captured in the above process, the contents of the remaining platinum, palladium, copper and iron in the slag were 9.55 g / t, 3.43 g / t, 0.12 g / t, 3.9 g / t ( Figure 4 ), the calculated recovery rates of platinum are 63.04%, palladium 96.19%, copper 82.09% and iron 90.63% ( Figure 5 ). Example 2
[0030] like Figure 1 As shown, the method for comprehensively recovering platinum, palladium, copper and iron by synergistic utilization of waste platinum-palladium leaching slag-copper slag comprises the following specific steps: grinding and sieving 25 g of copper slag and 25 g of waste platinum-palladium leaching slag to particle sizes of 200 and 100 mesh respectively, adding copper slag to the waste platinum-palladium leaching slag and mixing them evenly, wherein the ratio of the added amount of waste platinum-palladium leaching slag to copper slag is 1:1, and then heating to 1000°C at 7°C / min at room temperature under an inert carrier gas atmosphere (the inert carrier gas is nitrogen with a flow rate of 100 mL / min), and then heating to 1450°C at 5°C / min, reducing 180°C at a temperature of 1450°C, a basicity of 1.0, a reducing agent addition amount of 15%, and m(Na2O) / m(CaO)=1:3. min, during which Fe3O4 and other oxides are reduced to generate metal elements, and Pt / Pd is captured to form Fe-based-PGMs alloy. After the smelting slag is slowly cooled at high temperature, the slag phase is located in the upper layer, and the alloy phase settles in the bottom layer. The slag phase is aluminosilicate microcrystalline glass slag. The XRD diagram of the phase analysis ( Figure 3 ) indicates that it is aluminosilicate glass-ceramics. The alloy phase is Fe-based-PGMs alloy, which contains valuable metals such as platinum, palladium, iron, and copper.
[0031] After the copper slag was reduced and captured in the above process, the contents of the remaining platinum, palladium, copper and iron in the slag were 0.12 g / t, 0.08 g / t, 0.02 g / t, 1.16 g / t ( Figure 4 ), the calculated recovery rates of platinum are 99.57%, palladium are 99.75%, copper are 97.01%, and iron are 97.21% ( Figure 5 ). The prepared glass-ceramics were subjected to toxicity leaching experiments, such as Figure 6 As shown, the Cu, Zn, Pb, and F elements in the glass-ceramics all meet the US-EPA standards and can be regarded as harmless materials, thus achieving high-value utilization of slag. Example 3
[0032] like Figure 1As shown, the method for comprehensively recovering platinum, palladium, copper and iron by synergistic utilization of waste platinum-palladium leaching slag-copper slag comprises the following specific steps: grinding and sieving 25 g of copper slag and 25 g of waste platinum-palladium leaching slag to particle sizes of 200 and 100 mesh respectively, adding copper slag to the waste platinum-palladium leaching slag and mixing them evenly, wherein the ratio of the added amount of waste platinum-palladium leaching slag to copper slag is 1:1, and then heating to 1000°C at 7°C / min at room temperature under an inert carrier gas atmosphere (the inert carrier gas is nitrogen with a flow rate of 100 mL / min), and then heating to 1450°C at 5°C / min, reducing 180°C at a temperature of 1450°C, a basicity of 1.2, a reducing agent addition amount of 15%, and m(Na2O) / m(CaO)=1:3. min. During this process, oxides such as Fe3O4 are reduced to generate metal elements and capture platinum and palladium to form Fe-based-PGMs alloys. After the smelting slag is slowly cooled at high temperature, the slag phase of the slag is located in the upper layer and the alloy phase settles in the bottom layer. The slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy. The Fe-based-PGMs alloy contains valuable metals such as platinum, palladium, iron, and copper.
[0033] After the copper slag was reduced and captured in the above process, the contents of the remaining platinum, palladium, copper and iron in the slag were 6.25 g / t, 2.08 g / t, 0.08 g / t, 4.1 g / t ( Figure 4 ), the calculated recovery rates of platinum are 67.85%, palladium 96.93%, copper 88.06% and iron 90.15% ( Figure 5 ). Example 4
[0034] like Figure 1As shown, the method for comprehensively recovering platinum, palladium, copper and iron by synergistic utilization of waste platinum-palladium leaching slag-copper slag comprises the following specific steps: grinding and sieving 25 g of copper slag and 25 g of waste platinum-palladium leaching slag to particle sizes of 200 and 100 mesh respectively, adding copper slag to the waste platinum-palladium leaching slag and mixing them evenly, wherein the ratio of the added amount of waste platinum-palladium leaching slag to copper slag is 1:1, and then heating to 1000°C at 7°C / min at room temperature under an inert carrier gas atmosphere (the inert carrier gas is nitrogen with a flow rate of 100 mL / min), and then heating to 1450°C at 5°C / min, reducing 180°C at a temperature of 1450°C, a basicity of 1.0, a reducing agent addition amount of 6%, and m(Na2O) / m(CaO)=1:3. min. During this process, oxides such as Fe3O4 are reduced to generate metal elements and capture platinum and palladium to form Fe-based-PGMs alloys. After the smelting slag is slowly cooled at high temperature, the slag phase of the slag is located in the upper layer and the alloy phase settles in the bottom layer. The slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy. The Fe-based-PGMs alloy contains valuable metals such as platinum, palladium, iron, and copper.
[0035] After the copper slag was reduced and captured in the above process, ICP analysis showed that the remaining platinum, palladium, copper and iron contents in the slag were 1.27 g / t, 0.92 g / t, 0.11 g / t and 11.13 g / t, respectively. The calculated recovery rates of platinum, palladium, copper and iron were 90.72%, 98.94%, 83.58% and 73.27%, respectively. Example 5
[0036] like Figure 1 As shown, the method for comprehensively recovering platinum, palladium, copper and iron by synergistic utilization of waste platinum-palladium leaching slag-copper slag comprises the following specific steps: grinding and sieving 25 g of copper slag and 25 g of waste platinum-palladium leaching slag to particle sizes of 200 and 100 mesh respectively, adding copper slag to the waste platinum-palladium leaching slag and mixing them evenly, wherein the ratio of the added amount of waste platinum-palladium leaching slag to copper slag is 1:1, and then heating to 1000°C at 7°C / min at room temperature under an inert carrier gas atmosphere (the inert carrier gas is nitrogen with a flow rate of 100 mL / min), and then heating to 1450°C at 5°C / min, reducing 180°C at a temperature of 1450°C, a basicity of 1.0, an amount of reducing agent added of 18% of the mass of the copper slag, and m(Na2O) / m(CaO)=1:3. min. During this process, oxides such as Fe3O4 are reduced to generate metal elements and capture platinum and palladium to form Fe-based-PGMs alloys. After the smelting slag is slowly cooled at high temperature, the slag phase of the slag is located in the upper layer and the alloy phase settles in the bottom layer. The slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy. The Fe-based-PGMs alloy contains valuable metals such as platinum, palladium, iron, and copper.
[0037] After reduction and capture of the copper slag in the above process, ICP analysis showed that the remaining platinum, palladium, copper and iron contents in the slag were 0.53 g / t, 1.83 g / t, 0.03 g / t and 1.28 g / t, respectively. The calculated recovery rates of platinum, palladium, copper and iron were 97.29%, 97.32%, 95.52% and 96.93%, respectively. Example 6
[0038] like Figure 1 As shown, the method for comprehensively recovering platinum, palladium, copper and iron by synergistic utilization of waste platinum-palladium leaching slag-copper slag comprises the following specific steps: grinding and sieving 25 g of copper slag and 25 g of waste platinum-palladium leaching slag to particle sizes of 200 and 100 mesh respectively, adding copper slag to the waste platinum-palladium leaching slag and mixing them evenly, wherein the ratio of the added amount of waste platinum-palladium leaching slag to copper slag is 1:1, and then heating to 1000°C at 7°C / min at room temperature under an inert carrier gas atmosphere (the inert carrier gas is nitrogen with a flow rate of 100 mL / min), and then heating to 1450°C at 5°C / min, reducing 180°C under the conditions of temperature of 1450°C, alkalinity of 1.0, reducing agent addition amount of 30% of the mass of copper slag, and m(Na2O) / m(CaO)=1:1. min. During this process, oxides such as Fe3O4 are reduced to generate metal elements and capture platinum and palladium to form Fe-based-PGMs alloys. After the smelting slag is slowly cooled at high temperature, the slag phase of the slag is located in the upper layer and the alloy phase settles in the bottom layer. The slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy. The Fe-based-PGMs alloy contains valuable metals such as platinum, palladium, iron, and copper.
[0039] After reduction and capture of the copper slag in the above process, ICP analysis showed that the remaining platinum, palladium, copper and iron contents in the slag were 0.43 g / t, 1.69 g / t, 0.05 g / t and 0.98 g / t, respectively. The calculated recovery rates of platinum, palladium, copper and iron were 97.86%, 98.21%, 96.35% and 97.77%, respectively. Example 7
[0040] like Figure 1As shown, the method for comprehensively recovering platinum, palladium, copper and iron by synergistic utilization of waste platinum-palladium leaching slag-copper slag comprises the following specific steps: grinding and sieving 25 g of copper slag and 25 g of waste platinum-palladium leaching slag to particle sizes of 200 and 100 mesh respectively, adding copper slag to the waste platinum-palladium leaching slag and mixing them evenly, wherein the ratio of the added amount of waste platinum-palladium leaching slag to copper slag is 1:1, and then heating to 1000°C at 7°C / min at room temperature under an inert carrier gas atmosphere (the inert carrier gas is nitrogen with a flow rate of 100 mL / min), and then heating to 1450°C at 5°C / min, reducing 180°C at a temperature of 1450°C, a basicity of 1.0, an amount of reducing agent added of 15% of the mass of the copper slag, and m(Na2O) / m(CaO)=1:1. min. During this process, oxides such as Fe3O4 are reduced to generate metal elements and capture platinum and palladium to form Fe-based-PGMs alloys. After the smelting slag is slowly cooled at high temperature, the slag phase of the slag is located in the upper layer and the alloy phase settles in the bottom layer. The slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy. The Fe-based-PGMs alloy contains valuable metals such as platinum, palladium, iron, and copper.
[0041] After the copper slag was reduced and captured in the above process, ICP analysis showed that the remaining platinum, palladium, copper and iron contents in the slag were 8.19 g / t, 3.93 g / t, 0.12 g / t and 9.25 g / t, respectively. The calculated recovery rates of platinum, palladium, copper and iron were 53.63%, 93.43%, 82.09% and 77.79%, respectively. Example 8
[0042] like Figure 1 As shown, the method for comprehensively recovering platinum, palladium, copper and iron by synergistic utilization of waste platinum-palladium leaching slag-copper slag comprises the following specific steps: grinding and sieving 25 g of copper slag and 25 g of waste platinum-palladium leaching slag to particle sizes of 200 and 200 mesh respectively, adding copper slag to the waste platinum-palladium leaching slag and mixing them evenly, wherein the ratio of the amount of waste platinum-palladium leaching slag to the amount of copper slag added is 1:1, and then heating to 1000°C at 7°C / min at room temperature under an inert carrier gas atmosphere (the inert carrier gas is nitrogen with a flow rate of 100 mL / min), and then heating to 1450°C at 5°C / min, reducing 180°C at a temperature of 1450°C, a basicity of 1.0, an amount of reducing agent added of 15% of the mass of the copper slag, and m(Na2O) / m(CaO)=1:5. min. During this process, oxides such as Fe3O4 are reduced to generate metal elements and capture platinum and palladium to form Fe-based-PGMs alloys. After the smelting slag is slowly cooled at high temperature, the slag phase of the slag is located in the upper layer and the alloy phase settles in the bottom layer. The slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy. The Fe-based-PGMs alloy contains valuable metals such as platinum, palladium, iron, and copper.
[0043] After reduction and capture of the copper slag in the above process, ICP analysis showed that the remaining platinum, palladium, copper and iron contents in the slag were 1.18 g / t, 0.42 g / t, 0.03 g / t and 1.60 g / t, respectively. The calculated recovery rates of platinum, palladium, copper and iron were 93.71%, 99.36%, 94.93% and 96.15%, respectively. Example 9
[0044] like Figure 1 As shown, the method for comprehensively recovering platinum, palladium, copper and iron by synergistic utilization of waste platinum-palladium leaching slag-copper slag comprises the following specific steps: grinding and sieving 25 g of copper slag and 25 g of waste platinum-palladium leaching slag to particle sizes of 50 and 100 mesh respectively, adding copper slag to the waste platinum-palladium leaching slag and mixing them evenly, wherein the ratio of the added amount of waste platinum-palladium leaching slag to copper slag is 1:1, and then heating to 1000°C at 7°C / min at room temperature under an inert carrier gas atmosphere (the inert carrier gas is nitrogen with a flow rate of 100 mL / min), and then heating to 1375°C at 5°C / min, reducing 180°C at a temperature of 1375°C, a basicity of 1.0, an amount of reducing agent added of 15% of the mass of the copper slag, and m(Na2O) / m(CaO)=1:3. min. During this process, oxides such as Fe3O4 are reduced to generate metal elements and capture platinum and palladium to form Fe-based-PGMs alloys. After the smelting slag is slowly cooled at high temperature, the slag phase of the slag is located in the upper layer and the alloy phase settles in the bottom layer. The slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy. The Fe-based-PGMs alloy contains valuable metals such as platinum, palladium, iron, and copper.
[0045] After the copper slag was reduced and captured in the above process, ICP analysis showed that the remaining platinum, palladium, copper and iron contents in the slag were 15.13 g / t, 5.48 g / t, 0.21 g / t and 14.85 g / t, respectively. The calculated recovery rates of platinum, palladium, copper and iron were 19.03%, 90.55%, 69.11% and 64.34%, respectively. Example 10
[0046] like Figure 1As shown, the method for comprehensively recovering platinum, palladium, copper and iron by synergistic utilization of waste platinum-palladium leaching slag-copper slag comprises the following specific steps: grinding and sieving 25 g of copper slag and 25 g of waste platinum-palladium leaching slag to particle sizes of 150 and 100 mesh respectively, adding copper slag to the waste platinum-palladium leaching slag and mixing them evenly, wherein the ratio of the added amount of waste platinum-palladium leaching slag to copper slag is 1:1, and then heating to 1000°C at 7°C / min at room temperature under an inert carrier gas atmosphere (the inert carrier gas is nitrogen with a flow rate of 100 mL / min), and then heating to 1475°C at 5°C / min, reducing 180°C at a temperature of 1475°C, a basicity of 1.0, an amount of reducing agent added of 15% of the mass of the copper slag, and m(Na2O) / m(CaO)=1:3. min. During this process, oxides such as Fe3O4 are reduced to generate metal elements and capture platinum and palladium to form Fe-based-PGMs alloys. After the smelting slag is slowly cooled at high temperature, the slag phase of the slag is located in the upper layer and the alloy phase settles in the bottom layer. The slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy. The Fe-based-PGMs alloy contains valuable metals such as platinum, palladium, iron, and copper.
[0047] After the copper slag was reduced and captured in the above process, ICP analysis showed that the remaining platinum, palladium, copper and iron contents in the slag were 0.07 g / t, 0.05 g / t, 0.01 g / t and 0.61 g / t, respectively. The calculated recovery rates of platinum, palladium, copper and iron were 99.69%, 99.93%, 98.51% and 98.55%, respectively. Embodiment 11
[0048] like Figure 1 As shown, the method for comprehensively recovering platinum, palladium, copper and iron by synergistic utilization of waste platinum-palladium leaching slag-copper slag comprises the following specific steps: 8.3 g of copper slag and 41.7 g of waste platinum-palladium leaching slag are respectively ground and sieved to particle sizes of 200 and 100 mesh, and then the copper slag is added to the waste platinum-palladium leaching slag and mixed evenly, wherein the ratio of the added amount of copper slag to the waste platinum-palladium leaching slag is 0.2:1, and then under an inert carrier gas atmosphere (the inert carrier gas is nitrogen, with a flow rate of 100 mL / min), the temperature is increased to 1000°C at 7°C / min at room temperature, and then the temperature is increased to 1450°C at 5°C / min, and the temperature is reduced to 180°C at a temperature of 1450°C, a basicity of 1.0, a reducing agent addition amount of 15% of the mass of the copper slag, and m(Na2O) / m(CaO) =1:3. min. During this process, oxides such as Fe3O4 are reduced to generate metal elements and capture platinum and palladium to form Fe-based-PGMs alloys. After the smelting slag is slowly cooled at high temperature, the slag phase of the slag is located in the upper layer and the alloy phase settles in the bottom layer. The slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy. The Fe-based-PGMs alloy contains valuable metals such as platinum, palladium, iron, and copper.
[0049] After reduction and capture of the copper slag in the above process, ICP analysis showed that the remaining platinum, palladium, copper and iron contents in the slag were 14.42 g / t, 23.42 g / t, 0.09 g / t and 9.01 g / t, respectively. The calculated recovery rates of platinum, palladium, copper and iron were 61.59%, 82.11%, 84.40% and 78.36%, respectively. Example 12
[0050] like Figure 1 As shown, the method for comprehensively recovering platinum, palladium, copper and iron by synergistic utilization of waste platinum-palladium leaching slag-copper slag comprises the following specific steps: grinding and sieving 22.2 g of copper slag and 27.8 g of waste platinum-palladium leaching slag to particle sizes of 100 and 100 mesh respectively, adding copper slag to the waste platinum-palladium leaching slag and mixing them evenly, wherein the ratio of the added amount of copper slag to the waste platinum-palladium leaching slag is 0.8:1, and then heating to 1000°C at 7°C / min at room temperature under an inert carrier gas atmosphere (the inert carrier gas is nitrogen with a flow rate of 100 mL / min), and then heating to 1450°C at 5°C / min, reducing 180°C at a temperature of 1450°C, a basicity of 1.0, an amount of reducing agent added of 15% of the mass of the copper slag, and m(Na2O) / m(CaO)=1:3. min. During this process, oxides such as Fe3O4 are reduced to generate metal elements and capture platinum and palladium to form Fe-based-PGMs alloys. After the smelting slag is slowly cooled at high temperature, the slag phase of the slag is located in the upper layer and the alloy phase settles in the bottom layer. The slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy. The Fe-based-PGMs alloy contains valuable metals such as platinum, palladium, iron, and copper.
[0051] After the copper slag was reduced and captured in the above process, ICP analysis showed that the contents of remaining platinum, palladium, copper and iron in the slag were 0.36 g / t, 0.06 g / t, 0.04 g / t and 3.34 g / t, respectively. The calculated recovery rates of platinum, palladium, copper and iron were 99.04%, 99.95%, 94.37% and 91.98%, respectively. Embodiment 13
[0052] like Figure 1As shown, the method for comprehensively recovering platinum, palladium, copper and iron by synergistic utilization of waste platinum-palladium leaching slag-copper slag comprises the following specific steps: grinding and sieving 25 g of copper slag and 25 g of waste platinum-palladium leaching slag to particle sizes of 200 and 100 mesh respectively, adding copper slag to the waste platinum-palladium leaching slag and mixing them evenly, wherein the ratio of the added amount of waste platinum-palladium leaching slag to copper slag is 1:1, and then heating to 1000°C at 7°C / min at room temperature under an inert carrier gas atmosphere (the inert carrier gas is nitrogen with a flow rate of 50 mL / min), and then heating to 1300°C at 5°C / min, reducing 60% of the copper slag under the conditions of temperature of 1300°C, alkalinity of 1.0, reducing agent addition amount of 5% of the mass of copper slag, and m(Na2O) / m(CaO)=1:3. min. During this process, oxides such as Fe3O4 are reduced to generate metal elements and capture platinum and palladium to form Fe-based-PGMs alloys. After the smelting slag is slowly cooled at high temperature, the slag phase of the slag is located in the upper layer and the alloy phase settles in the bottom layer. The slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy. The Fe-based-PGMs alloy contains valuable metals such as platinum, palladium, iron, and copper.
[0053] After the copper slag was reduced and captured in the above process, ICP analysis showed that the remaining platinum, palladium, copper and iron contents in the slag were 3.45 g / t, 0.91 g / t, 0.07 g / t and 5.56 g / t, respectively. The calculated recovery rates of platinum, palladium, copper and iron were 80.85%, 98.55%, 90.15% and 86.65%, respectively. Embodiment 14
[0054] like Figure 1 As shown, the method for comprehensively recovering platinum, palladium, copper and iron by synergistic utilization of waste platinum-palladium leaching slag-copper slag comprises the following specific steps: grinding and sieving 25 g of copper slag and 25 g of waste platinum-palladium leaching slag to particle sizes of 200 and 100 mesh respectively, adding copper slag to the waste platinum-palladium leaching slag and mixing them evenly, wherein the ratio of the amount of waste platinum-palladium leaching slag to the amount of copper slag added is 1:1, and then heating to 1000°C at 7°C / min at room temperature under an inert carrier gas atmosphere (the inert carrier gas is nitrogen with a flow rate of 200 mL / min), and then heating to 1550°C at 5°C / min, reducing 150°C at a temperature of 1550°C, a basicity of 1.0, an amount of reducing agent added of 30% of the mass of the copper slag, and m(Na2O) / m(CaO)=1:3. min. During this process, oxides such as Fe3O4 are reduced to generate metal elements and capture platinum and palladium to form Fe-based-PGMs alloys. After the smelting slag is slowly cooled at high temperature, the slag phase of the slag is located in the upper layer and the alloy phase settles in the bottom layer. The slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy. The Fe-based-PGMs alloy contains valuable metals such as platinum, palladium, iron, and copper.
[0055] After the copper slag was reduced and captured in the above process, ICP analysis showed that the remaining platinum, palladium, copper and iron contents in the slag were 0.19 g / t, 0.05 g / t, 0.02 g / t and 0.09 g / t, respectively. The calculated recovery rates of platinum, palladium, copper and iron were 99.21%, 99.94%, 97.61% and 99.62%, respectively.
[0056] In summary, the present invention uses waste platinum-palladium leaching slag-copper slag as raw materials, SiO2-Al2O3-CaO as the basic slag system in the mixed slag, CaO and Na2O as fluxes, and waste cathode carbon as a reducing agent, and the recovery rates of platinum, palladium, copper and iron are as high as 99.57%, 99.75%, 97.01% and 97.21% respectively. The present invention has great significance for the efficient and comprehensive utilization of waste platinum-palladium leaching slag and copper slag.
[0057] The above disclosure is only part of the embodiments of the present invention, which cannot be used to limit the scope of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention are still within the scope of the invention.
Claims
1. A method for comprehensive recovery of valuable metals by synergistic utilization of waste platinum and palladium leaching residues and copper slag, characterized in that: The steps include: (1) Grinding and sieving the waste platinum-palladium leaching slag and copper slag respectively to obtain waste platinum-palladium leaching slag powder and copper slag powder; adding the copper slag powder to the waste platinum-palladium leaching slag powder and mixing the two evenly to obtain a mixed powder; (2) After adding a reducing agent and a flux to the mixed powder, reduction smelting is performed at a temperature of 1300-1550 °C for 30-180 min under an inert carrier gas atmosphere until the metal oxides in the slag are reduced to form metal elements and platinum and palladium are captured to form an Fe-based-PGMs alloy; (3) The smelted slag is slowly cooled, the slag phase of the slag is located in the upper layer, and the alloy phase settles to the bottom layer; the slag phase is aluminosilicate microcrystalline glass slag, and the alloy phase is Fe-based-PGMs alloy.
2. The method for comprehensive recovery of valuable metals by synergistic utilization of waste platinum and palladium leaching residues and copper slag as claimed in claim 1, characterized in that: The mass ratio of the waste platinum-palladium leaching residue to the copper residue in step (1) is 0.2-1.0:
1.
3. The method for comprehensive recovery of valuable metals by synergistic utilization of waste platinum and palladium leaching residues and copper slag as claimed in claim 1, characterized in that: The amount of the reducing agent added in step (2) is 5-30% of the mass of the copper slag, and the reducing agent is waste cathode carbon.
4. The method for comprehensive recovery of valuable metals by synergistic utilization of waste platinum and palladium leaching residues and copper slag as claimed in claim 1, characterized in that: The flux in step (2) is CaO and Na2O, and the mass ratio of CaO to Na2O is 1:1~1:
5.
5. The method for comprehensive recovery of valuable metals by synergistic utilization of waste platinum and palladium leaching residues and copper slag as claimed in claim 1, characterized in that: In step (2), before reduction smelting, the temperature is raised to 1000°C at 7°C / min at room temperature in a positive pressure atmosphere furnace, and then raised to 1300-1550°C at 5°C / min.
6. The method for comprehensive recovery of valuable metals by synergistic utilization of waste platinum and palladium leaching residues and copper slag as claimed in claim 1, characterized in that: The inert carrier gas atmosphere in step (2) is nitrogen or argon, with a flow rate of 50-200 mL / min.
7. The method for comprehensive recovery of valuable metals by synergistic utilization of waste platinum and palladium leaching residues and copper slag as claimed in claim 1, characterized in that: The sieving in step (2) is performed through a 50-200 mesh sieve.