Method for strengthening precious metal recovery and all-component utilization through cooperation of plasma and smelting

Abstract

The invention provides a method for strengthening precious metal recovery and all-component utilization through cooperation of plasma and smelting, and relates to the field of solid waste recovery. Performing first mixing on the solid waste and a reducing agent to obtain a first mixture; under the working atmosphere, the first mixture is subjected to plasma smelting, and high-temperature liquid-state slag, a liquid-state sulfonium phase and a liquid-state alloy phase are obtained; the liquid sulfonium phase and the liquid alloy phase are subjected to hydrometallurgy to recover precious metal; carrying out water quenching on the high-temperature liquid slag to obtain a glass material; grinding and drying the glass material to obtain a treated glass material; carrying out second mixing on the treated glass material and a binder solution to obtain a second mixture; carrying out mould pressing and heat treatment on the second mixture to obtain glass ceramics; the solid waste comprises a waste automobile catalyst, flue gas desulfurization gypsum slag and cyanidation tailings and / or pyrite cinder. According to the method, various complex secondary resources are cooperatively processed through the plasma smelting technology, and efficient enrichment of precious metal and high-value conversion of all material components are achieved.

Description

Technical Field

[0001] The present application relates to the field of solid waste recycling, and in particular to a method for plasma synergistic smelting to enhance precious metal recovery and full component utilization. Background Art

[0002] Waste automotive catalysts are a valuable secondary resource for platinum group metals (PGMs), including platinum, palladium, and rhodium. Their recovery holds immense economic and strategic value. Cyanidation, a common process for gold extraction, produces cyanidation tailings containing residual gold (Au), silver (Ag), and various other metals, including iron and copper. This tailings not only occupies land but also poses serious environmental risks. Furthermore, the vast amount of flue gas desulfurization (FGD) gypsum slag (primarily composed of calcium sulfate) produced by industries such as coal-fired power plants poses an environmental challenge.

[0003] Sulfuric acid slag is primarily derived from the solid residue formed during the roasting of sulfide minerals to produce sulfuric acid. This type of slag typically contains high concentrations of iron oxides and is enriched with precious metals such as gold and silver, as well as valuable metal components such as copper, zinc, and lead. Due to the limitations of traditional processing techniques, the long-term storage of large quantities of sulphuric acid slag not only consumes land resources but also poses the potential risk of heavy metal leaching and environmental pollution. In the current context of green metallurgy and the development of a circular economy, sulphuric acid slag is gaining increasing attention for its dual properties as both an iron resource carrier and a precious metal enrichment medium.

[0004] Existing precious metal recovery technologies are mainly divided into pyrometallurgy and hydrometallurgy. Pyrometallurgy, such as plasma smelting, uses high temperatures to enrich precious metals into metal or matte phase collectors, and has the advantages of fast processing speed and strong adaptability to raw materials. However, traditional pyrometallurgical processes usually require the addition of large amounts of collectors and slag-forming agents (such as lime and quartz), which increases costs and energy consumption, and the resulting slag is usually treated as a low-value product or waste, failing to achieve high-value utilization of all components. Hydrometallurgical processes are complex, often use strong acids and alkalis, are prone to secondary pollution, and are not effective in treating complex multi-component raw materials.

[0005] Furthermore, the four types of solid waste mentioned above are currently typically treated or disposed of using separate, unrelated process routes. For example, spent catalysts are sent to specialized precious metal recovery plants, cyanide tailings are treated harmlessly or subjected to inefficient gold extraction, and desulfurization gypsum is primarily used to produce building materials or landfilled. This decentralized treatment model results in lengthy process chains, large equipment investments, high energy consumption, and low resource utilization.

[0006] Therefore, there is an urgent need to develop a new integrated technology that can synergistically process multiple solid wastes, reduce external material consumption through material circulation within the process, and achieve efficient recovery of precious metals and complete resource utilization of remaining components. Summary of the Invention

[0007] The purpose of this application is to provide a method for plasma synergistic smelting to enhance precious metal recovery and full component utilization to solve the above problems.

[0008] To achieve the above objectives, the present application provides a method for plasma synergistic smelting to enhance precious metal recovery and full component utilization, comprising: performing a first mixing of the solid waste and the reducing agent to obtain a first mixture; Plasma melting the first mixture under a working atmosphere to obtain high-temperature liquid slag, liquid matte phase and liquid alloy phase; The liquid matte phase and the liquid alloy phase are subjected to hydrometallurgical recovery of precious metals respectively; The high-temperature liquid slag is water quenched to obtain glass frit; Grinding and drying the glass frit to obtain treated glass frit; performing a second mixing of the treated glass frit and the binder solution to obtain a second mixture; Molding and heat-treating the second mixture to obtain glass-ceramics; The solid waste includes waste automobile catalysts, flue gas desulfurization gypsum slag and cyanide tailings and / or sulfuric acid slag.

[0009] Optionally, the method for plasma synergistic smelting to enhance precious metal recovery and full component utilization satisfies at least one of the following conditions: A. The components of the waste automobile catalyst, calculated based on the total mass as 100%, include: Al2O335%-98%, SiO20%-40%, MgO 0%-15%, Fe2O30%-10%, CaO 0%-3%, and the balance is other catalytic additives and precious metals; The mass content of precious metals in the waste automobile catalyst is 1000-5000 g / t; B. The composition of the flue gas desulfurization gypsum slag includes CaSO4; C. The composition of the cyanide tailings, based on the total mass as 100%, includes: Fe2O315%-50%, SiO220%-50%, Al2O31%-10%, CaO 2-10%, Cu 0-5%, Pb 0-5%, Zn 0-5%, the balance is other metal oxides and sulfides and precious metals; The mass content of precious metals in the cyanide tailings is 10-250g / t; D. The composition of the sulfuric acid slag, taking the total mass as 100%, comprises: Fe2O330-90%, SiO25-20%, Al2O30.5-10%, CaO 0.5-10%, Cu 0-5%, Pb 0-5%, Zn 0-5%, the balance is other metal oxides and sulfides and precious metals; The mass content of the precious metal in the sulfuric acid slag is 5-300g / t; Optionally, the method for plasma synergistic smelting to enhance precious metal recovery and full component utilization satisfies at least one of the following conditions: A. in the first mixture, the mass ratio of CaO to SiO2 is 0.3-0.4:1, the mass ratio of MgO to SiO2 is 0.2-0.3:1, and the mass ratio of Al2O3 to SiO2 is 0.18-0.3:1; B. The mass of the iron element in the first mixture accounts for 10%-25% of the total mass, and the molar amount of the iron element is 1 to 2.5 times the molar amount of the sulfur element.

[0010] Optionally, the method for plasma synergistic smelting to enhance precious metal recovery and full component utilization satisfies at least one of the following conditions: A. the water content of the first mixture is less than 3%; B. the particle size of the first mixture is 20 mesh to 200 mesh; C. The reducing agent includes coke.

[0011] Optionally, the method for plasma synergistic smelting to enhance precious metal recovery and full component utilization satisfies at least one of the following conditions: A. The working atmosphere includes inert gas and / or reducing gas; B. The temperature of the plasma melting is 1550-1800°C and the time is 0.5-3h.

[0012] Optionally, the method for plasma synergistic smelting to enhance precious metal recovery and full component utilization satisfies at least one of the following conditions: A. When the working atmosphere includes argon and hydrogen, the molar amount of the reducing agent is 0.1-0.6 times the molar amount of the iron element; When the working atmosphere includes an inert gas, the molar amount of the reducing agent is 1.5-3 times the molar amount of the iron element; B. When the working atmosphere comprises argon and hydrogen, the total volume of the working atmosphere is calculated as 100%, including: 60%-90%Ar, 10%-40%H2; C. The total flow rate of the working gas introduced into the working atmosphere is 2-30m 3 / h.

[0013] Optionally, when preparing the first mixture, a formulation agent is also added; The formulation includes one or more of calcium-oxygen compounds, silicon-oxygen compounds, iron-oxygen compounds and magnesium-oxygen compounds.

[0014] Optionally, the method for plasma synergistic smelting to enhance precious metal recovery and full component utilization satisfies at least one of the following conditions: A. After the treatment, the proportion of -200 mesh particle size in the glass frit is 60%-85%; B. The moisture content of the glass frit after the treatment is less than 3%; C. The flexural strength of the glass-ceramics is ≥50 MPa, and the Vickers hardness is ≥19 Gpa.

[0015] Optionally, the method for plasma synergistic smelting to enhance precious metal recovery and full component utilization satisfies at least one of the following conditions: A. The mass of the binder in the binder solution is 8%-12% of the mass of the treated glass frit; B. The binder in the binder solution includes polyethylene glycol and polyvinyl alcohol; The mass ratio of the polyethylene glycol to the polyvinyl alcohol is 2-5:2; C. The mass concentration of the binder solution is 5%-8%.

[0016] Optionally, the heat treatment includes a first heat treatment and a second heat treatment performed sequentially; The first heat treatment has a heating rate of 3-5°C / min, an end point temperature of 750-850°C, and a holding time of 2-4h; The heating rate of the second heat treatment is 2-3°C / min, the end temperature is 900-1050°C, and the holding time is 3-6h; The cooling rate of the heat treatment is 5-10°C / min.

[0017] Compared with the prior art, the advantages of this application include: The method of plasma synergistic smelting to enhance precious metal recovery and full component utilization provided in the present application utilizes plasma smelting technology to synergistically process a variety of complex secondary resources, and achieves efficient enrichment of precious metals and high-value conversion of all material components by in-situ generation of composite alloy capture agents and slag-forming agents; this method eliminates the disposal problems of various solid wastes at the source, avoids secondary pollution that may be generated during the dispersed treatment process, and reduces the amount of chemical reagents added during the smelting process, thereby greatly reducing fixed asset investment and processing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0019] Figure 1 This is a schematic flow chart of the method for plasma collaborative smelting enhanced precious metal recovery and full component utilization provided in Example 1. DETAILED DESCRIPTION

[0020] Currently, the treatment of four types of solid waste—spent automotive catalysts, flue gas desulfurization gypsum residue, and cyanide tailings and / or sulfuric acid cinders—is completely separate. This model results in significant duplication of investment and inefficient resource utilization. Furthermore, most metallurgical processes follow a linear economic model: "resources-products-wastes." Even recycling processes often generate new, difficult-to-treat waste residues or wastewater. To address the challenges presented by this model, this application proposes the following solution.

[0021] First, the solution provided in this application is explained in more detail as follows: The present application provides a method for plasma synergistic smelting to enhance precious metal recovery and full component utilization, comprising: performing a first mixing of the solid waste and the reducing agent to obtain a first mixture; Plasma melting the first mixture under a working atmosphere to obtain high-temperature liquid slag, liquid matte phase and liquid alloy phase; The liquid matte phase and the liquid alloy phase are subjected to hydrometallurgical recovery of precious metals respectively; The high-temperature liquid slag is water quenched to obtain glass frit; It should be noted that water quenching inhibits the uncontrolled natural crystallization of the high-temperature liquid slag during the cooling process, thereby obtaining an amorphous glass body with uniform chemical composition, namely glass frit; Grinding and drying the glass frit to obtain treated glass frit; performing a second mixing of the treated glass frit and the binder solution to obtain a second mixture; Molding and heat-treating the second mixture to obtain glass-ceramics; In some embodiments, the blank is pressed into a desired shape by molding or the like, and the desired shape is not limited and can be any desired shape; The solid waste includes waste automobile catalysts, flue gas desulfurization gypsum slag and cyanide tailings and / or sulfuric acid slag.

[0022] Traditional pyrometallurgical precious metal recovery generally uses a single metal as a collector, most commonly iron, copper, or lead. These single-metal collectors have different affinities for different precious metals, and at high temperatures, the partition coefficient of precious metals between the collector and slag is limited, resulting in some precious metal loss in the slag. This application recognizes that these four wastes have natural complementarity in their main chemical composition: spent automotive catalysts are rich in Al2O3 and SiO2 (slag skeleton), cyanide tailings / sulfuric acid slag are rich in Fe2O3 (collector precursor), and gypsum is rich in CaSO4 (slagging agent precursor). Non-major components in the waste play a key synergistic role in the high-temperature plasma smelting process: cyanide tailings / sulfuric acid slag are typically rich in metal oxides or residues such as Cu, Zn, and Pb. Under strong reducing conditions, these metallic elements react with FeO (from the reduction of Fe₂O₃) to form multicomponent matte phases such as Cu-Fe-S, Zn-Fe-S, and Pb-Fe-S, as well as intermetallic compounds such as Cu-Pt and Pd-Cu. The distribution coefficient of copper-based matte for palladium is 2-3 times higher than that of pure iron matte, and the capture capacity of lead-based alloys for platinum is superior to that of a single iron collector. This complex multicomponent system, composed of the "intrinsic" components of solid waste, generates an ideal phase separation (liquid slag, liquid matte, and liquid alloy) in the molten pool through in-situ chemical reactions, achieving differentiated and efficient enrichment of different precious metals.

[0023] The core mechanism of plasma melting technology lies in its unique ultra-high temperature gradient field and active plasma environment, which provide ideal metallurgical reaction conditions for complex solid waste systems: the extreme ultra-high temperature conditions in the plasma arc zone instantly break the kinetic limitations in conventional pyrometallurgy, allowing refractory platinum group metal oxides (such as PtO2, RhO3) and complex aluminosilicate carriers to quickly dissociate. At the same time, the high-energy electrons and ions in the plasma produce a strong physicochemical activation effect on the surface of solid waste particles, significantly reducing the activation energy of precious metal reduction; more importantly, the strong electric and magnetic field effects formed in the plasma environment promote violent electromagnetic stirring inside the molten pool, accelerating the mass transfer process of multi-metal capture alloys such as Fe-Cu-Zn-Pb in the melt, allowing complex intermetallic compounds (such as Pt3Fe, PdCu, RhZn, etc.) that were originally difficult to achieve at conventional melting temperatures to be rapidly formed and reach thermodynamic equilibrium. Finally, driven by the density difference, the high-density precious metal-enriched metallographic phase and matte phase settle to the bottom of the furnace, and the low-density aluminosilicate slag floats up, achieving clear separation of the three phases and efficient enrichment and recovery of precious metals.

[0024] Therefore, this application solves the environmental problems of four different solid wastes through process synergy, in-situ synthesis, and utilization of all waste components. It also completely transforms them into valuable commodities, achieving maximum resource utilization efficiency and economic benefits. The specific analysis is as follows: On the one hand, in a reducing smelting atmosphere, metal oxides such as iron and copper in the cyanide tailings / sulfuric acid slag are reduced to metals and fused with other metal elements (such as lead and zinc) to form an in-situ multi-element alloy collector phase. This multi-element alloy collector phase has similar physical and chemical properties to precious metals, enabling efficient capture of platinum group metals such as platinum, palladium, and rhodium (PGMs) in spent automotive catalysts and gold in the cyanide tailings / sulfuric acid slag. On the other hand, the decomposition of desulfurized gypsum in a reducing atmosphere and high temperature, at temperatures above 1100°C, with carbon acting as a reducing agent, causes the following two core reactions: CaSO4 + 2C → CaS + 2CO2; 3CaSO4+ CaS → 4CaO + 4SO2; The generated CaO is a strong alkaline oxide. As a network-modifying component, it destroys the three-dimensional network structure of [SiO4] tetrahedrons and [AlO4] tetrahedrons, significantly reducing the melting point and viscosity of the aluminosilicate system, prompting the originally refractory SiO2-Al2O3 system to quickly transform into a CaO-MgO-Al2O3-SiO2 quaternary silicate melt with good fluidity. Under strong reducing conditions, sulfur dioxide gas will react with metallic iron in the molten pool to generate ferrous sulfide (FeS). The reaction is as follows: 3Fe + SO2 → FeS + 2FeO; The generated FeS reacts with a small amount of Cu that is not captured by the alloy phase to form iron-copper matte (FeS-Cu2S). This matte phase is insoluble in the metal phase and the slag phase. Since its density is between that of the metal and the slag, it will form an independent liquid phase layer. Among them, matte is an excellent capture agent for sulfur-philic elements. The cyanide tailings contain a certain amount of silver (Ag), which has a strong affinity for sulfur. Therefore, this in-situ formed iron-copper matte is primarily used to selectively enrich silver. This is equivalent to opening up an efficient "second capture channel" for specific elements such as silver in addition to the primary capture process. This not only improves the silver recovery rate but also simplifies the subsequent separation and purification of precious metals, allowing the Ag-rich matte phase to be treated separately from the PGMs (platinum group metals)-rich alloy phase. Compared with traditional iron or copper collectors, the in-situ formed composite alloy + matte phase collector can achieve higher and more comprehensive precious metal recovery rates, especially for complex raw materials (containing Pt, Pd, Rh, Au, and Ag). In addition, the present application uses a core process (plasma melting) to transform and redistribute matter and energy; the core chemical reagents required for the process are all generated in situ during the process from waste automobile catalysts, flue gas desulfurization gypsum slag and cyanide tailings and / or sulfuric acid slag. This is not only a cost savings, but also a closure of the material flow, reducing dependence on external primary resources. There is no waste at the output end of the process. The main product is an alloy phase enriched with precious metals, and the secondary product is a matte phase enriched with silver. Both are high-value intermediate products. The slag, which accounts for the largest mass fraction, is a high-quality raw material for producing high-value-added microcrystalline glass ceramics because its composition is precisely designed into an ideal CMAS system in the process.

[0025] In some embodiments, the plasma synergistic smelting enhanced precious metal recovery and full component utilization method meets at least one of the following conditions: A. The components of the waste automobile catalyst, calculated based on the total mass as 100%, include: Al2O335%-98%, SiO20%-40%, MgO 0%-15%, Fe2O30%-10%, CaO 0%-3%, and the balance is other catalytic additives and precious metals; Optionally, based on the total mass of the waste automobile catalyst being 100%, Al2O3 may be 35%, 40%, 50%, 60%, 70%, 80%, 90%, 98%, or any value between 35% and 98%, SiO2 may be 0%, 10%, 20%, 30%, 40%, or any value between 0% and 40%, MgO may be 0%, 5%, 10%, 15%, or any value between 0% and 15%, Fe2O3 may be 0%, 5%, 10%, or any value between 0% and 10%, and CaO may be 0%, 1%, 2%, 3%, or any value between 0% and 3%. The mass content of precious metals in the waste automobile catalyst is 1000-5000 g / t; Optionally, the mass content of the precious metal in the waste automobile catalyst may be 1000 g / t, 2000 g / t, 3000 g / t, 4000 g / t, 5000 g / t, or any value between 1000 and 5000 g / t; In some embodiments, the mass content of Pt in the waste automobile catalyst precious metals is 150-400 g / t, the mass content of Pd is 800-1500 g / t, and the mass content of Rh is 100-300 g / t; Optionally, the mass content of Pt may be 150 g / t, 200 g / t, 300 g / t, 400 g / t, or any value between 150 and 400 g / t; the mass content of Pd may be 800 g / t, 900 g / t, 1000 g / t, 1100 g / t, 1200 g / t, 1300 g / t, 1400 g / t, 1500 g / t, or any value between 800 and 1500 g / t; and the mass content of Rh may be 100 g / t, 200 g / t, 300 g / t, or any value between 100 and 300 g / t. B. The composition of the flue gas desulfurization gypsum slag includes CaSO4; C. The composition of the cyanide tailings, based on the total mass as 100%, includes: Fe2O315%-50%, SiO220%-50%, Al2O31%-10%, CaO 2-10%, Cu 0-5%, Pb 0-5%, Zn 0-5%, the balance is other metal oxides and sulfides and precious metals; Optionally, the composition of the cyanide tailings is calculated based on the total mass as 100%, Fe2O3 may be 15%, 20%, 30%, 40%, 50% or any value between 15% and 50%, SiO2 may be 20%, 30%, 40%, 50% or any value between 20% and 50%, Al2O3 may be 1%, 5%, 10% or any value between 1% and 10%, CaO may be 2%, 5%, 10% or any value between 2% and 10%, Cu may be 0%, 1%, 2%, 3%, 4%, 5% or any value between 0% and 5%, Pb may be 0%, 1%, 2%, 3%, 4%, 5% or any value between 0% and 5%, and Zn may be 0%, 1%, 2%, 3%, 4%, 5% or any value between 0% and 5%; The mass content of precious metals in the cyanide tailings is 10-250g / t; Optionally, the mass content of precious metals in the cyanide tailings may be 10 g / t, 50 g / t, 100 g / t, 150 g / t, 200 g / t, 250 g / t, or any value between 10 and 250 g / t; In some embodiments, the mass content of Au in the cyanide tailings precious metals is 0.5-50 g / t, and the mass content of Ag is 10-200 g / t; The mass content of Au in the cyanide tailings precious metal may be 0.5 g / t, 1 g / t, 5 g / t, 10 g / t, 20 g / t, 30 g / t, 40 g / t, 50 g / t or any value between 0.5 and 50 g / t; the mass content of Ag may be 10 g / t, 50 g / t, 100 g / t, 200 g / t or any value between 10 and 200 g / t; D. The composition of the sulfuric acid slag, taking the total mass as 100%, comprises: Fe2O330-90%, SiO25-20%, Al2O30.5-10%, CaO 0.5-10%, Cu 0-5%, Pb 0-5%, Zn 0-5%, the balance is other metal oxides and sulfides and precious metals; Optionally, the composition of the sulfuric acid slag is 100% by total mass, and Fe2O3 may be 30%, 40%, 50%, 60%, 70%, 80%, 90% or any value between 30-90%, SiO2 may be 5%, 10%, 15%, 20% or any value between 5-20%, Al2O3 may be 0.5%, 1%, 5%, 10% or any value between 0.5%-10%, CaO may be 0.5%, 1%, 2%, 5%, 10% or any value between 0.5%-10%, Cu may be 0%, 1%, 2%, 3%, 4%, 5% or any value between 0-5%, Pb may be 0%, 1%, 2%, 3%, 4%, 5% or any value between 0-5%, and Zn may be 0%, 1%, 2%, 3%, 4%, 5% or any value between 0-5%; The mass content of the precious metal in the sulfuric acid slag is 5-300g / t; Optionally, the mass content of the precious metal in the sulfuric acid slag can be 5 g / t, 10 g / t, 50 g / t, 100 g / t, 200 g / t, 300 g / t or any value between 5 and 300 g / t; In some embodiments, the mass content of Au in the sulfuric acid slag precious metals is 0.5-50 g / t, and the mass content of Ag is 10-250 g / t.

[0026] Optionally, the mass content of Au in the sulfuric acid slag precious metal may be 0.5 g / t, 1 g / t, 5 g / t, 10 g / t, 20 g / t, 30 g / t, 40 g / t, 50 g / t, or any value between 0.5 and 50 g / t; the mass content of Ag may be 10 g / t, 50 g / t, 100 g / t, 150 g / t, 200 g / t, 250 g / t, or any value between 10 and 250 g / t; In some embodiments, the plasma synergistic smelting enhanced precious metal recovery and full component utilization method meets at least one of the following conditions: A. in the first mixture, the mass ratio of CaO to SiO2 is 0.3-0.4:1, the mass ratio of MgO to SiO2 is 0.2-0.3:1, and the mass ratio of Al2O3 to SiO2 is 0.18-0.3:1; Optionally, the mass ratio of CaO to SiO2 in the first mixture may be 0.3:1, 0.35:1, 0.4:1, or any value between 0.3 and 0.4:1; the mass ratio of MgO to SiO2 may be 0.2:1, 0.25:1, 0.3:1, or any value between 0.2 and 0.3:1; and the mass ratio of Al2O3 to SiO2 may be 0.18:1, 0.2:1, 0.3:1, or any value between 0.18 and 0.3:1; It should be noted that the reasons and beneficial effects of the above mass ratio limitations are as follows: the CaO / SiO2 mass ratio is controlled within the range of 0.3-0.4, which ensures that the silicate melt has appropriate alkalinity and fluidity, which can effectively promote the rapid separation of the precious metal phase and the slag phase, and provide an ideal CaO-SiO2 basic network structure for the subsequent preparation of microcrystalline glass from the slag; the MgO / SiO2 mass ratio is controlled within the range of 0.2-0.3, which can not only stabilize the high-temperature melt structure and prevent excessive corrosion of the furnace lining, but more importantly, the magnesium-containing silicate phase formed under this ratio is formed in the microcrystalline glass. During the preparation process, it can act as a nucleating agent to promote uniform crystallite precipitation, improving the mechanical strength and chemical stability of the glass. Controlling the Al2O3 / SiO2 mass ratio within the range of 0.18-0.3 balances the rational regulation of melt viscosity during smelting and the performance optimization of the glass-ceramics product. At this ratio, Al2O3 ensures good melt fluidity at 1550-1800°C while forming a rigid aluminum oxide tetrahedron network structure in the glass-ceramics, significantly enhancing the strength of the final product and achieving dual optimization of metallurgical separation efficiency and resource-based product quality. B. The mass of the iron element in the first mixture accounts for 10%-25% of the total mass, and the molar amount of the iron element is 1 to 2.5 times the molar amount of the sulfur element.

[0027] Optionally, the mass of the iron element in the first mixture may account for 10%, 15%, 20%, 25% or any value between 10% and 25% of the total mass, and the molar amount of the iron element may be 1 times, 1.5 times, 2 times, 2.5 times or any value between 1 times and 2.5 times the molar amount of the sulfur element; It should be noted that the limitation of 10%-25% by mass of iron element and 1-2.5 times of Fe / S molar ratio is based on comprehensive consideration of precious metal capture mechanism and phase equilibrium optimization: when the iron content is lower than 10%, the number of FeS-based matte phase and alloy phase formed is insufficient to provide sufficient capture carrier for precious metals, resulting in the loss of precious metals in the slag phase; and when the iron content exceeds 25%, the system will produce excessive metallic iron phase, which will not only consume additional reducing agent and increase costs, but also dilute the concentration of precious metals in the alloy phase and reduce the subsequent wet recovery efficiency; the control of Fe / S molar ratio is more critical, and the purpose of the limitation is to construct a two-phase capture system in which metallic iron phase and matte phase coexist, giving full play to the synergistic advantages of the two phases: when the Fe / S molar ratio is controlled within this range, the sulfur element in the system will preferentially react with part of the iron. An FeS-based matte phase should be generated, and the remaining excess iron exists in a metallic state and forms a multi-element alloy phase with heterogeneous metals such as Cu, Zn, and Pb; this dual-phase coexistence structure has significant capture advantages - the matte phase (FeS-CuS-ZnS) exhibits strong chemical affinity and good mutual solubility for palladium and platinum, while the metal alloy phase (Fe-Cu-Pb) effectively collects precious metals through the formation of intermetallic compounds; compared with a simple matte phase system, this matte phase-alloy phase dual capture mechanism not only expands the capture range of precious metals, but also regulates the distribution of precious metals between different chemical states through the dynamic balance between the two phases, avoiding the escape of certain precious metals into the slag phase due to chemical form restrictions, thereby achieving full-spectrum capture of precious metals in various valence states and compound states, and significantly improving the overall recovery rate. In some embodiments, the method of plasma synergistic smelting to enhance precious metal recovery and full component utilization meets at least one of the following conditions: A. the water content of the first mixture is less than 3%; Optionally, the water content of the first mixture may be 0.1%, 1%, 2%, 2.9% or any value <3%; In some embodiments, the first mixture is dried at 90-200° C. to a moisture content of <3%; B. the particle size of the first mixture is 20 mesh to 200 mesh; Optionally, the particle size of the first mixture may be 20 mesh, 50 mesh, 100 mesh, 150 mesh, 200 mesh, or any value between 20 mesh and 200 mesh; In some embodiments, the first mixture is ground to a particle size between 20 mesh and 200 mesh; C. The reducing agent includes coke.

[0028] In some embodiments, the plasma synergistic smelting enhanced precious metal recovery and full component utilization method meets at least one of the following conditions: A. The working atmosphere includes inert gas and / or reducing gas; B. The temperature of the plasma melting is 1550-1800°C and the time is 0.5-3h.

[0029] Optionally, the temperature of the plasma melting may be 1550° C., 1600° C., 1700° C., 1800° C., or any value between 1550° C. and 1800° C., and the time may be 0.5 h, 1 h, 2 h, 3 h, or any value between 0.5 and 3 h. In some embodiments, the plasma synergistic smelting enhanced precious metal recovery and full component utilization method meets at least one of the following conditions: A. When the working atmosphere includes argon and hydrogen, the molar amount of the reducing agent is 0.1-0.6 times the molar amount of the iron element; Optionally, when the working atmosphere includes argon and hydrogen, the molar amount of the reducing agent can be 0.1 times, 0.2 times, 0.3 times, 0.4 times, 0.5 times, 0.6 times, or any value between 0.1 and 0.6 times the molar amount of the iron element; It should be further explained that coke reacts with silicon oxide at high temperatures (>1500°C) to form silicon, which then forms ferrosilicon with iron. Its insoluble properties seriously restrict the recovery rate of precious metals. When the working gas of the plasma melting furnace used in this application is a reducing gas, the amount of coke can be reduced, which greatly reduces the thermodynamic trend of ferrosilicon formation. When the working atmosphere includes an inert gas, the molar amount of the reducing agent is 1.5-3 times the molar amount of the iron element; Optionally, when the working atmosphere includes an inert gas, the molar amount of the reducing agent may be 1.5 times, 2 times, 2.5 times, 3 times, or any value between 1.5 and 3 times the molar amount of the iron element; B. When the working atmosphere comprises argon and hydrogen, the total volume of the working atmosphere is calculated as 100%, including: 60%-90%Ar, 10%-40%H2; Optionally, when the working atmosphere includes argon and hydrogen, the total volume of the working atmosphere is 100%, Ar can be 60%, 70%, 80%, 90% or any value between 60% and 90%, and H2 can be 10%, 20%, 30%, 40% or any value between 10% and 40%; C. The total flow rate of the working gas introduced into the working atmosphere is 2-30m 3 / h.

[0030] Optionally, the total flow rate of the working gas introduced into the working atmosphere can be 2 m 3 / h、5m 3 / h, 10 m 3 / h, 20 m 3 / h, 30 m 3 / h or 2-30m 3 Any value between / h.

[0031] In some embodiments, when performing the first mixture, a formulation agent is also added; The formulation includes one or more of calcium-oxygen compounds, silicon-oxygen compounds, iron-oxygen compounds and magnesium-oxygen compounds.

[0032] It is important to note that the addition of blending agents is intended to precisely control the chemical composition and physical properties of the melt, ensuring that key mass ratios such as CaO / SiO2, MgO / SiO2, and Al2O3 / SiO2 fall within the set range. This not only satisfies the need for ideal phase separation during the smelting process, but also provides the optimal compositional basis for the subsequent preparation of high-quality glass-ceramics from the slag. The targeted addition of specific oxide blending agents not only compensates for deviations and heterogeneities in the original solid waste composition, but also enables full-process quality control, from efficient capture of precious metals to high-value utilization of slag, ensuring that the glass-ceramics products possess excellent mechanical strength, chemical stability, and thermal stability.

[0033] In some embodiments, the plasma synergistic smelting enhanced precious metal recovery and full component utilization method meets at least one of the following conditions: A. After the treatment, the proportion of -200 mesh particle size in the glass frit is 60%-85%; Optionally, the proportion of -200 mesh particles in the processed glass material can be 60%, 70%, 80%, 85%, or any value between 60% and 85%; B. The moisture content of the glass frit after the treatment is less than 3%; Optionally, the moisture content of the glass frit after treatment may be 0.1%, 1%, 2%, 2.9% or any value <3%; C. The flexural strength of the glass-ceramics is ≥50 MPa, and the Vickers hardness is ≥19 Gpa.

[0034] Optionally, the flexural strength of the microcrystalline glass can be 50Mpa, 51Mpa, 52Mpa, 53Mpa, 54Mpa, 55Mpa, 56Mpa, 57Mpa, 58Mpa, 59Mpa, 60Mpa, 65Mpa, 70Mpa, 75Mpa, 80Mpa or any value ≥50Mpa, and the Vickers hardness can be 19Gpa, 20Gpa, 22Gpa, 24Gpa, 26Gpa, 28Gpa, 30Gpa, 35Gpa, 40Gpa or any value ≥19Gpa.

[0035] In some embodiments, the plasma synergistic smelting enhanced precious metal recovery and full component utilization method meets at least one of the following conditions: A. The mass of the binder in the binder solution is 8%-12% of the mass of the treated glass frit; Optionally, the mass of the binder in the binder solution may be 8%, 9%, 10%, 11%, 12% or any value between 8% and 12% of the mass of the processed glass frit; B. The binder in the binder solution includes polyethylene glycol and polyvinyl alcohol; It should be noted that when preparing the binder solution, polyethylene glycol and polyvinyl alcohol are added at 60-80°C and stirred thoroughly until completely dissolved; this binder solution can provide good plasticity and bonding strength during molding, and completely decomposes during the subsequent sintering process without affecting the performance of the product; The mass ratio of the polyethylene glycol to the polyvinyl alcohol is 2-5:2; Optionally, the mass ratio of polyethylene glycol to polyvinyl alcohol can be 2:2, 3:2, 4:2, 5:2 or any value between 2 and 5:2; C. The mass concentration of the binder solution is 5%-8%.

[0036] Optionally, the mass concentration of the binder solution may be 5%, 6%, 7%, 8%, or any value between 5% and 8%.

[0037] In some embodiments, the heat treatment includes a first heat treatment and a second heat treatment performed sequentially; The first heat treatment has a heating rate of 3-5°C / min, an end point temperature of 750-850°C, and a holding time of 2-4h; Optionally, the heating rate of the first heat treatment may be 3°C / min, 4°C / min, 5°C / min, or any value between 3-5°C / min, the end temperature may be 750°C, 800°C, 850°C, or any value between 750-850°C, and the holding time may be 2h, 3h, 4h, or any value between 2-4h; It should be noted that during the first heat treatment process, to ensure the formation of a large number of tiny, evenly distributed crystal nuclei, the temperature range of 750-850°C is the optimal temperature range for the crystal nucleation rate; The heating rate of the second heat treatment is 2-3°C / min, the end temperature is 900-1050°C, and the holding time is 3-6h; Optionally, the heating rate of the second heat treatment can be 2°C / min, 2.5°C / min, 3°C / min, or any value between 2-3°C / min, the end temperature can be 900°C, 950°C, 1000°C, 1050°C, or any value between 900-1050°C, and the holding time can be 3h, 4h, 5h, 6h, or any value between 3-6h; It should be noted that after the nucleation of the first heat treatment is completed, the temperature is continued to be raised to 900-1050℃ at a heating rate of 2-3℃ / min and kept at this temperature platform for 3-6 hours to allow the crystal nuclei formed in the early stage to fully grow to form a small and interwoven grain structure. This temperature is the optimal temperature range for the crystal growth rate; The cooling rate of the heat treatment is 5-10°C / min.

[0038] Optionally, the cooling rate of the heat treatment can be 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min or any value between 5-10°C / min.

[0039] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, the conditions are carried out according to conventional conditions or manufacturer recommendations. If the manufacturer is not specified for reagents or instruments used, they are all conventional products that can be purchased commercially.

[0040] Example 1 This embodiment provides a method for plasma synergistic smelting to enhance precious metal recovery and full component utilization. The process of the method is as follows: Figure 1 The specific steps are as follows: S1: 100 g of scrapped automotive catalyst (platinum group metal scrap) was collected. Its main chemical composition (mass percentage) was: Al2O3 35.96%, SiO2 32.97%, MgO 9.06%, Fe2O3 6.22%, CaO 0.42%, and the remainder was other catalytic additives and precious metals. The total precious metal content (PGMs) was 1636.8 g / t, including Pt 237.11 g / t, Pd 1238.43 g / t, and Rh 161.26 g / t. Take 200g of cyanide tailings (containing gold and silver slag), and its main chemical composition (mass percentage) is: Fe2O3 40.77%, SiO2 34.75%, Al2O3 5.2%, CaO 5.8%, Cu 4.33%, Pb 4.86%, Zn 3.42%, and the balance is other metal oxides, sulfides and precious metals; the total precious metal content is 61.8 g / t, including 10.8g / t of Au and 51 g / t of Ag; Take 140g of desulfurized gypsum slag, the main component of which is CaSO4, with a content of 39.12% in terms of CaO and a S content of 22.3%; Take 25g of industrial-grade magnesium oxide and 80g of industrial-grade silicon oxide as supplementary slag-forming agents, and take 25g of coke as a reducing agent. The molar amount of the reducing agent is 1.9 times the molar amount of the iron element. The above materials are dried, crushed, and thoroughly mixed to obtain a mixed charge having a moisture content of less than 3% and a particle size between 20 mesh and 200 mesh. The mass ratio of CaO to SiO2 in the mixed charge is 0.37:1, the mass ratio of MgO to SiO2 is 0.24:1, and the mass ratio of Al2O3 to SiO2 is 0.25:1. The mass of iron element accounts for 10.78% of the total mass, and the molar amount of iron element is 1.11 times the molar amount of sulfur element. S2: Add the above mixed charge into a DC non-transferred arc plasma melting furnace with a power of 15kW, use nitrogen as the plasma working gas, and the flow rate is 4m 3 / h to maintain arc stability. After adding the charge, first introduce pure nitrogen to purge the residual oxygen. After the nitrogen content in the tail gas is greater than 99%, the ventilation is stopped and the plasma arc is started to heat and melt the charge. The overall temperature of the molten pool is controlled at 1600±50℃ and the melting time is 1.5h. S3: During smelting, Fe2O3, CuO, etc. in the charge are reduced to metallic Fe and Cu, and together with Pb, Zn, etc., form Fe-Cu based alloy droplets, which settle and gather at the bottom of the furnace, while capturing PGMs and Au; CaSO4 decomposes to form CaO and SO2, CaO enters the slag, and SO2 reacts with part of Fe to form FeS matte phase, enriching Ag; the slag phase is mainly composed of CaO, Al2O3, SiO2, and MgO, and floats on the upper layer after clarification; the flue gas generated during the smelting process is collected, treated, and then discharged; After the smelting was completed, 61.86g of precious metal-rich alloy phase, 42.53g of silver-rich matte phase and about 353.68g of liquid slag (slag phase) were released in sequence. The analysis results of each phase are shown in Tables 1 and 2. After analysis, the precious metal recovery rates based on the slag phase were relatively high, with platinum (Pt) 98.21%, rhodium (Rh) 96.49%, palladium (Pd) 99.77%, gold (Au) 96.73% and silver (Ag) 95.84%. Table 1 Mass content of precious metals in each smelting phase (g / t)

[0041] Table 2 Distribution of precious metals in each smelting phase (%)

[0042] Note: The calculation formula for the precious metal distribution rate in each smelting phase is: alloy phase precious metal distribution rate % = (alloy phase mass × precious metal mass fraction in alloy phase) / (raw material mass × precious metal mass fraction in raw material) × 100%; matte phase precious metal distribution rate % = (matte phase mass × precious metal mass fraction in matte phase) / (raw material mass × precious metal mass fraction in raw material) × 100%; slag phase precious metal distribution rate % = (slag phase mass × precious metal mass fraction in slag phase) / (raw material mass × precious metal mass fraction in raw material) × 100%; Among them, due to the error of precious metal mass fraction in the detection process, there will be a certain error in the final precious metal distribution rate in each smelting phase. Therefore, it is normal for the error of precious metal distribution rate in each smelting phase to be within 2%.

[0043] S4: water quenching the silver-rich matte phase of the precious metal-enriched alloy phase and recovering the precious metals by hydrometallurgy; The discharged liquid slag is directly poured into water for water quenching to obtain glassy granular material. The glass material is taken and crushed to -200 mesh, accounting for 73%, and dried until the weight no longer changes (water content <3%). The glass powder is mixed with a composite binder solution of polyethylene glycol and polyvinyl alcohol (mass ratio of 3:2) (the mass concentration of the binder solution is 6.5%, and the mass of the binder is 10% of the mass of the glass powder) and formed by molding; the green body is placed in a muffle furnace with a heating rate of 5°C / min and kept at 800°C for 2h for nucleation treatment; then the temperature is increased to 1000°C at a heating rate of 3°C / min and kept at this temperature for 4h for crystallization treatment; finally, the temperature is cooled to room temperature at a cooling rate of 5°C / min to complete the preparation of microcrystalline glass, and 344.13g of microcrystalline glass ceramics are finally obtained, with a flexural strength of 58.95MPa and a Vickers hardness of 19.62GPa.

[0044] Example 2 This embodiment provides a method for plasma synergistic smelting to enhance precious metal recovery and full component utilization. The difference from Example 1 is that sulfuric acid slag is used instead of cyanide tailings as the precious metal (Au, Ag) source and iron source.

[0045] The specific steps are as follows: S1: 100 g of scrap automobile catalyst was collected. Its main chemical composition (mass percentage) was: Al2O3 35.96%, SiO2 32.97%, MgO 9.06%, Fe2O3 6.22%, CaO 0.42%, and the remainder was other catalytic additives and precious metals. The total precious metal content (PGMs) was 1636.8 g / t, including Pt 237.11 g / t, Pd 1238.43 g / t, and Rh 161.26 g / t. Take 200g of sulfuric acid slag, and its main chemical composition (mass percentage) is: Fe2O381.92%, SiO26.15%, Al2O31.23%, CaO 0.92%, Cu 0.96%, Pb 0.12%, Zn 1.13%, and the balance is other metal oxides, sulfides and precious metals; the total precious metal content is 77 g / t, including 10.2g / t of Au and 66.8g / t of Ag; Take 120g of desulfurized gypsum slag, the main component of which is CaSO4, with a content of 39.12% in terms of CaO and a S content of 22.3%; Take 20g of industrial-grade magnesium oxide and 100g of industrial-grade silicon oxide as supplementary slag-forming agents, take 42g of coke as a reducing agent, and the molar amount of the reducing agent is 1.64 times the molar amount of the iron element; The above materials are fully mixed, dried, and ground to obtain a mixed charge having a moisture content of less than 3% and a particle size between 20 mesh and 200 mesh. The mass ratio of CaO to SiO2 in the mixed charge is 0.34:1, the mass ratio of MgO to SiO2 is 0.21:1, and the mass ratio of Al2O3 to SiO2 is 0.26:1. The mass of iron element accounts for 20.45% of the total mass, and the molar amount of iron element is 2.38 times the molar amount of sulfur element. S2: Add the above mixed charge into a DC non-transferred arc plasma melting furnace with a power of 15kW, use nitrogen as the plasma working gas, and the flow rate is 4m 3 / h to maintain arc stability. After adding the charge, first introduce pure nitrogen to purge the residual oxygen. After the nitrogen content in the tail gas is greater than 99%, the ventilation is stopped and the plasma arc is started to heat and melt the charge. The overall temperature of the molten pool is controlled at 1600±50℃ and the melting time is 1.5h. S3: During smelting, Fe2O3, CuO, etc. in the charge are reduced to metallic Fe and Cu, and together with Pb, Zn, etc., form Fe-Cu based alloy droplets, which settle and gather at the bottom of the furnace, while capturing PGMs and Au; CaSO4 decomposes to form CaO and SO2, CaO enters the slag, and SO2 reacts with part of Fe to form FeS matte phase, enriching Ag; the slag phase is mainly composed of CaO, Al2O3, SiO2, and MgO, and floats to the upper layer after clarification; After the smelting was completed, 88.95g of precious metal-rich alloy phase, 60.25g of silver-rich matte phase and about 273.85g of liquid slag (slag phase) were released in sequence. The analysis results of each phase are shown in Tables 3 and 4. After analysis, the precious metal recovery rates based on the slag phase were relatively high, including 99.19% for platinum (Pt), 97.11% for rhodium (Rh), 99.05% for palladium (Pd), 98.39% for gold (Au) and 98.16% for silver (Ag). Table 3 Mass content of precious metals in each smelting phase (g / t)

[0046] Table 4 Distribution of precious metals in each smelting phase (%)

[0047] Note: The same method as in Example 1 was used to calculate the distribution ratio of precious metals in each smelting phase; S4: The discharged liquid slag is directly poured into water for water quenching to obtain glassy granular material, the glass material is crushed to -200 mesh and accounts for 73%, and dried until the weight no longer changes (water content <3%), the glass powder is mixed with a composite binder solution of polyethylene glycol and polyvinyl alcohol (mass ratio of 3:2) (the mass concentration of the binder solution is 6.5%, and the mass of the binder is 10% of the mass of the glass powder), and formed by molding; the blank is placed in a muffle furnace with a heating rate of 5℃ / min and kept at 800℃ for 2h for nucleation treatment; then the temperature is increased to 1000℃ at a heating rate of 3℃ / min and kept at this temperature for 4h for crystallization treatment; finally, the temperature is cooled to room temperature at a cooling rate of 5℃ / min to complete the preparation of microcrystalline glass, and finally 266.45g of microcrystalline glass ceramics is obtained, whose flexural strength reaches 57.2MPa and Vickers hardness reaches 19.3GPa.

[0048] Example 3 This embodiment provides a method for plasma synergistic smelting to enhance precious metal recovery and full component utilization. The difference from Example 1 is that a combination of reducing gas and inert gas is used as the working gas, while the amount of coke added is reduced.

[0049] The specific steps are as follows: S1: 100 g of scrap automobile catalyst was collected. Its main chemical composition (mass percentage) was: Al2O3 35.96%, SiO2 32.97%, MgO 9.06%, Fe2O3 6.22%, CaO 0.42%, and the remainder was other catalytic additives and precious metals. The total precious metal content (PGMs) was 1636.8 g / t, including Pt 237.11 g / t, Pd 1238.43 g / t, and Rh 161.26 g / t. Take 200g of cyanide tailings, and its main chemical composition (mass percentage) is: Fe2O340.77%, SiO234.75%, Al2O35.2%, CaO 5.8%, Cu 4.33%, Pb 4.86%, Zn 3.42%, and the balance is other metal oxides, sulfides and precious metals; the total precious metal content is 61.8 g / t, including Au 10.8g / t and Ag 51 g / t; Take 140g of desulfurized gypsum slag, the main component of which is CaSO4, with a content of 39.12% in terms of CaO and a S content of 22.3%; Take 25g of industrial-grade magnesium oxide and 80g of industrial-grade silicon oxide as supplementary slag-forming agents, take 5g of coke as a reducing agent, and the molar amount of the reducing agent is 0.38 times the molar amount of the iron element; The above materials are thoroughly mixed, dried, and ground to obtain a mixed charge having a moisture content of less than 3% and a particle size between 20 mesh and 200 mesh. The mass ratio of CaO to SiO2 in the mixed charge is 0.37:1, the mass ratio of MgO to SiO2 is 0.24:1, and the mass ratio of Al2O3 to SiO2 is 0.25:1. The mass of iron element accounts for 11.17% of the total mass, and the molar amount of iron element is 1.11 times the molar amount of sulfur element. S2: Add the above mixed charge into a 15kW DC non-transferred arc plasma melting furnace, using hydrogen and argon as plasma working gases, where the hydrogen integral rate is 15%, the argon integral rate is 85%, and the flow rate is 4m 3 / h to maintain arc stability. After adding the charge, first introduce pure nitrogen to purge residual oxygen. After the nitrogen content in the tail gas is greater than 99%, stop the ventilation and start the plasma arc. First, pre-melt in a pure argon atmosphere. After a uniform molten pool is formed, adjust the working gas to 85% Ar + 15% H2, start the reduction reaction, and control the overall temperature of the molten pool at 1600 ± 50 ° C. The melting time is 1.5 hours. S3: During smelting, Fe2O3, CuO, etc. in the charge are reduced to metallic Fe and Cu, and together with Pb, Zn, etc., form Fe-Cu based alloy droplets, which settle and gather at the bottom of the furnace, while capturing PGMs and Au; CaSO4 decomposes to form CaO and SO2, CaO enters the slag, and SO2 reacts with part of Fe to form FeS matte phase, enriching Ag; the slag phase is mainly composed of CaO, Al2O3, SiO2, and MgO, and floats to the upper layer after clarification; After the smelting was completed, 63.76g of precious metal-rich alloy phase, 42.29g of silver-rich matte phase and about 346.88g of liquid slag (slag phase) were released in sequence. The analysis results of each phase are shown in Tables 5 and 6. After analysis, the precious metal recovery rates based on the slag phase were relatively high, including 98.98% for platinum (Pt), 97.20% for rhodium (Rh), 99.75% for palladium (Pd), 97.59% for gold (Au) and 96.67% for silver (Ag). Table 5 Mass content of precious metals in each smelting phase (g / t)

[0050] Table 6 Distribution of precious metals in each smelting phase (%)

[0051] Note: The same method as in Example 1 was used to calculate the distribution ratio of precious metals in each smelting phase; S4: The discharged liquid slag is directly poured into water for water quenching to obtain glassy granular material, the glass material is crushed to -200 mesh and accounts for 73%, and dried until the weight no longer changes (water content <3%), the glass powder is mixed with a composite binder solution of polyethylene glycol and polyvinyl alcohol (mass ratio of 3:2) (the mass concentration of the binder solution is 6.5%, and the mass of the binder is 10% of the mass of the glass powder), and formed by molding; the blank is placed in a muffle furnace with a heating rate of 5℃ / min and kept at 800℃ for 2h for nucleation treatment; then the temperature is increased to 1000℃ at a heating rate of 3℃ / min and kept at this temperature for 4h for crystallization treatment; finally, the temperature is cooled to room temperature at a cooling rate of 5℃ / min to complete the preparation of microcrystalline glass, and finally 336.82g of microcrystalline glass ceramics is obtained, whose flexural strength reaches 56.54MPa and Vickers hardness reaches 19.71GPa.

[0052] Comparative Example 1 The difference from Example 1 is that the amount of cyanide tailings added in this comparative example is reduced during batching, resulting in the iron element in the mixed charge accounting for less than 10% by mass, and the final recovery rate of precious metals is relatively low; The specific steps are as follows: S1: 100 g of scrap automobile catalyst was collected. Its main chemical composition (mass percentage) was: Al2O3 35.96%, SiO2 32.97%, MgO 9.06%, Fe2O3 6.22%, CaO 0.42%, and the remainder was other catalytic additives and precious metals. The total precious metal content (PGMs) was 1636.8 g / t, including Pt 237.11 g / t, Pd 1238.43 g / t, and Rh 161.26 g / t. Take 100g of cyanide tailings (containing gold and silver), and its main chemical composition (mass percentage) is: Fe2O3 40.77%, SiO2 34.75%, Al2O3 5.2%, CaO 5.8%, Cu 4.33%, Pb 4.86%, Zn 3.42%, with the remainder being other metal oxides, sulfides, and precious metals. The total precious metal content is 61.8 g / t, including 10.8 g / t of Au and 51 g / t of Ag. Take 140g of desulfurized gypsum slag, the main component of which is CaSO4, with a content of 39.12% in terms of CaO and a S content of 22.3%; Take 25g of industrial-grade magnesium oxide and 80g of industrial-grade silicon oxide as supplementary slag-forming agents, and take 15g of coke as a reducing agent. Both the slag-forming agent and the reducing agent are additives. The above materials are dried, ground, and fully mixed to obtain a mixed charge having a moisture content of less than 3% and a particle size between 20 mesh and 200 mesh. The mass ratio of CaO to SiO2 in the mixed charge is 0.41:1, the mass ratio of MgO to SiO2 is 0.27:1, and the mass ratio of Al2O3 to SiO2 is 0.28:1. The mass of iron element accounts for 7.15% of the total mass, and the molar amount of iron element is 0.6 times the molar amount of sulfur element. S2: Add the above mixed charge into a DC non-transferred arc plasma melting furnace with a power of 15kW, use nitrogen as the plasma working gas, and the flow rate is 4m 3 / h to maintain arc stability. After adding the charge, first introduce pure nitrogen to purge the residual oxygen. After the nitrogen content in the tail gas is greater than 99%, the ventilation is stopped and the plasma arc is started to heat and melt the charge. The overall temperature of the molten pool is controlled at 1600±50℃ and the melting time is 1.5h. S3: During smelting, Fe2O3, CuO, etc. in the charge are reduced to metallic Fe and Cu, and together with Pb, Zn, etc., form Fe-Cu based alloy droplets, which settle and gather at the bottom of the furnace, while capturing PGMs and Au; CaSO4 decomposes to form CaO and SO2, CaO enters the slag, and SO2 reacts with part of Fe to form FeS matte phase, enriching Ag; the slag phase is mainly composed of CaO, Al2O3, SiO2, and MgO, and floats to the upper layer after clarification; After the smelting was completed, 32.27 g of precious metal-rich alloy phase, 23.31 g of silver-rich matte phase and about 300.69 g of liquid slag (slag phase) were released in sequence. The analysis results of each phase are shown in Tables 7 and 8. After analysis, the precious metal recovery rates based on the slag phase were relatively high, including 82.75% for platinum (Pt), 79.68% for rhodium (Rh), 80.36% for palladium (Pd), 80.51% for gold (Au) and 62.86% for silver (Ag). Table 7 Mass content of precious metals in each smelting phase (g / t)

[0053] Table 8 Distribution of precious metals in each smelting phase (%)

[0054] Note: The same method as in Example 1 was used to calculate the distribution ratio of precious metals in each smelting phase; S4: The discharged liquid slag is directly poured into water for water quenching to obtain glassy granular material, the glass material is crushed to -200 mesh and accounts for 73%, and dried until the weight no longer changes (water content <3%), the glass powder is mixed with a composite binder solution of polyethylene glycol and polyvinyl alcohol (mass ratio of 3:2) (the mass concentration of the binder solution is 6.5%, and the mass of the binder is 10% of the mass of the glass powder), and formed by molding; the blank is placed in a muffle furnace with a heating rate of 5℃ / min and kept at 800℃ for 2h for nucleation treatment; then the temperature is increased to 1000℃ at a heating rate of 3℃ / min and kept at this temperature for 4h for crystallization treatment; finally, the temperature is cooled to room temperature at a cooling rate of 5℃ / min to complete the preparation of microcrystalline glass, and finally 292.57g of microcrystalline glass ceramics is obtained, whose flexural strength reaches 55.2MPa and Vickers hardness reaches 19.86GPa.

[0055] Comparative Example 2 The difference from Example 1 is that this comparative example increases the amount of waste automobile catalyst added during the mixing process, which leads to an increase in the mass fraction of the aluminum phase in the raw material, and Al2O3 / SiO2 in the raw material is 0.38; the flexural strength of the finally obtained microcrystalline glass is difficult to meet the requirements, and in this comparative example, due to the excessively high aluminum oxide content, its Vickers hardness is increased.

[0056] The specific steps are as follows: S1: 200 g of spent automotive catalyst was collected. Its main chemical composition (mass percentage) was: Al2O3 35.96%, SiO2 32.97%, MgO 9.06%, Fe2O3 6.22%, CaO 0.42%, and the remainder was other catalytic additives and precious metals. The total precious metal content (PGMs) was 1636.8 g / t, including Pt 237.11 g / t, Pd 1238.43 g / t, and Rh 161.26 g / t. Take 200g of cyanide tailings, and its main chemical composition (mass percentage) is: Fe2O340.77%, SiO234.75%, Al2O35.2%, CaO 5.8%, Cu 4.33%, Pb 4.86%, Zn 3.42%, and the balance is other metal oxides, sulfides and precious metals; the total precious metal content is 61.8 g / t, including Au 10.8g / t and Ag 51 g / t; Take 140g of desulfurized gypsum slag, the main component of which is CaSO4, with a content of 39.12% in terms of CaO and a S content of 22.3%; Take 25g of industrial-grade magnesium oxide and 80g of industrial-grade silicon oxide as supplementary slag-forming agents, and take 15g of coke as a reducing agent. The molar amount of the reducing agent is 1.06 times the molar amount of the iron element. The above materials are fully mixed, dried, and ground to obtain a mixed furnace charge with a moisture content of less than 3% and a particle size between 20 mesh and 200 mesh. The mass ratio of CaO to SiO2 in the mixed furnace charge is 0.31:1, the mass ratio of MgO to SiO2 is 0.25:1, and the mass ratio of Al2O3 to SiO2 is 0.38:1. The mass of iron element accounts for 9.97% of the total mass, and the molar amount of iron element is 1.18 times the molar amount of sulfur element. S2: Add the above mixed charge into a DC non-transferred arc plasma melting furnace with a power of 15kW, use nitrogen as the plasma working gas, and the flow rate is 4m 3 / h to maintain arc stability. After adding the charge, first introduce pure nitrogen to purge the residual oxygen. After the nitrogen content in the tail gas is greater than 99%, the ventilation is stopped and the plasma arc is started to heat and melt the charge. The overall temperature of the molten pool is controlled at 1600±50℃ and the melting time is 1.5h. S3: During smelting, Fe2O3, CuO, etc. in the charge are reduced to metallic Fe and Cu, and together with Pb, Zn, etc., form Fe-Cu based alloy droplets, which settle and gather at the bottom of the furnace, while capturing PGMs and Au; CaSO4 decomposes to form CaO and SO2, CaO enters the slag, and SO2 reacts with part of Fe to form FeS matte phase, enriching Ag; the slag phase is mainly composed of CaO, Al2O3, SiO2, and MgO, and floats to the upper layer after clarification; After the smelting was completed, 64.55g of precious metal-rich alloy phase, 46.61g of silver-rich matte phase and about 435.23g of liquid slag (slag phase) were released in sequence. The analysis results of each phase are shown in Tables 9 and 10. After analysis, the precious metal recovery rates based on the slag phase were relatively high, with platinum (Pt) 85.87%, rhodium (Rh) 78.27%, palladium (Pd) 82.62%, gold (Au) 84.89%, and silver (Ag) 74.95%. Table 9 Mass content of precious metals in each smelting phase (g / t)

[0057] Table 10 Distribution of precious metals in each smelting phase (%)

[0058] Note: The same method as in Example 1 was used to calculate the distribution ratio of precious metals in each smelting phase; S4: The discharged liquid slag is directly poured into water for water quenching to obtain glassy granular material, the glass material is crushed to -200 mesh and accounts for 73%, and dried until the weight no longer changes (water content <3%), the glass powder is mixed with a composite binder solution of polyethylene glycol and polyvinyl alcohol (mass ratio of 3:2) (the mass concentration of the binder solution is 6.5%, and the mass of the binder is 10% of the mass of the glass powder), and formed by molding; the blank is placed in a muffle furnace with a heating rate of 5℃ / min and kept at 800℃ for 2h for nucleation treatment; then the temperature is increased to 1000℃ at a heating rate of 3℃ / min and kept at this temperature for 4h for crystallization treatment; finally, the temperature is cooled to room temperature at a cooling rate of 5℃ / min to complete the preparation of microcrystalline glass, and finally 423.48g of microcrystalline glass ceramics are obtained, whose flexural strength reaches 46.3MPa and Vickers hardness reaches 20.85GPa.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

[0060] Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and to form different embodiments. For example, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is intended solely to enhance understanding of the overall background of this application and should not be construed as an admission or any implication that such information constitutes prior art known to those skilled in the art.

Claims

1. A method for plasma synergistic smelting to enhance precious metal recovery and full component utilization, characterized in that: include: performing a first mixing of the solid waste and the reducing agent to obtain a first mixture; Plasma melting the first mixture under a working atmosphere to obtain high-temperature liquid slag, liquid matte phase and liquid alloy phase; The liquid matte phase and the liquid alloy phase are subjected to hydrometallurgical recovery of precious metals respectively; The high-temperature liquid slag is water quenched to obtain glass frit; Grinding and drying the glass frit to obtain treated glass frit; performing a second mixing of the treated glass frit and the binder solution to obtain a second mixture; Molding and heat-treating the second mixture to obtain glass-ceramics; The solid waste includes waste automobile catalysts, flue gas desulfurization gypsum slag and cyanide tailings and / or sulfuric acid slag.

2. The method for plasma synergistic smelting enhanced precious metal recovery and full component utilization according to claim 1, characterized in that: At least one of the following conditions is met: A. The components of the waste automobile catalyst, calculated based on the total mass as 100%, include: Al2O3 35%-98%, SiO2 0%-40%, MgO 0%-15%, Fe2O3 0%-10%, CaO 0%-3%, and the balance is other catalytic additives and precious metals; The mass content of precious metals in the waste automobile catalyst is 1000-5000 g / t; B. The composition of the flue gas desulfurization gypsum slag includes CaSO4; C. The composition of the cyanide tailings, based on the total mass as 100%, includes: Fe2O315%-50%, SiO2 20%-50%, Al2O3 1%-10%, CaO 2-10%, Cu 0-5%, Pb 0-5%, Zn 0-5%, the balance is other metal oxides and sulfides and precious metals; The mass content of precious metals in the cyanide tailings is 10-250g / t; D. The composition of the sulfuric acid slag, taking the total mass as 100%, comprises: Fe2O330-90%, SiO25-20%, Al2O30.5-10%, CaO 0.5-10%, Cu 0-5%, Pb 0-5%, Zn 0-5%, the balance is other metal oxides and sulfides and precious metals; The mass content of the precious metals in the sulfuric acid slag is 5-300 g / t.

3. The method for plasma synergistic smelting enhanced precious metal recovery and full component utilization according to claim 1, characterized in that: At least one of the following conditions is met: A. in the first mixture, the mass ratio of CaO to SiO2 is 0.3-0.4:1, the mass ratio of MgO to SiO2 is 0.2-0.3:1, and the mass ratio of Al2O3 to SiO2 is 0.18-0.3:1; B. The mass of the iron element in the first mixture accounts for 10%-25% of the total mass, and the molar amount of the iron element is 1 to 2.5 times the molar amount of the sulfur element.

4. The method for plasma synergistic smelting enhanced precious metal recovery and full component utilization according to claim 1, characterized in that: At least one of the following conditions is met: A. the water content of the first mixture is less than 3%; B. the particle size of the first mixture is 20 mesh to 200 mesh; C. The reducing agent includes coke.

5. The method for plasma synergistic smelting enhanced precious metal recovery and full component utilization according to claim 1, characterized in that: At least one of the following conditions is met: A. The working atmosphere includes inert gas and / or reducing gas; B. The temperature of the plasma melting is 1550-1800°C and the time is 0.5-3h.

6. The method for plasma synergistic smelting enhanced precious metal recovery and full component utilization according to claim 5, characterized in that: At least one of the following conditions is met: A. When the working atmosphere includes argon and hydrogen, the molar amount of the reducing agent is 0.1-0.6 times the molar amount of the iron element; When the working atmosphere includes an inert gas, the molar amount of the reducing agent is 1.5-3 times the molar amount of the iron element; B. When the working atmosphere comprises argon and hydrogen, the total volume of the working atmosphere is calculated as 100%, including: 60%-90%Ar, 10%-40%H2; C. The total flow rate of the working gas introduced into the working atmosphere is 2-30m 3 / h.

7. The method for plasma synergistic smelting enhanced precious metal recovery and full component utilization according to claim 1, characterized in that: When making the first mixture, a formulation agent is also added; The formulation includes one or more of calcium-oxygen compounds, silicon-oxygen compounds, iron-oxygen compounds and magnesium-oxygen compounds.

8. The method for plasma synergistic smelting enhanced precious metal recovery and full component utilization according to claim 1, characterized in that: At least one of the following conditions is met: A. After the treatment, the proportion of -200 mesh particle size in the glass frit is 60%-85%; B. The moisture content of the glass frit after the treatment is less than 3%; C. The flexural strength of the glass-ceramics is ≥50 MPa, and the Vickers hardness is ≥19 Gpa.

9. The method for plasma synergistic smelting enhanced precious metal recovery and full component utilization according to claim 1, characterized in that: At least one of the following conditions is met: A. The mass of the binder in the binder solution is 8%-12% of the mass of the treated glass frit; B. The binder in the binder solution includes polyethylene glycol and polyvinyl alcohol; The mass ratio of the polyethylene glycol to the polyvinyl alcohol is 2-5:2; C. The mass concentration of the binder solution is 5%-8%.

10. The method for plasma synergistic smelting enhanced precious metal recovery and full component utilization according to any one of claims 1 to 9, characterized in that: The heat treatment includes a first heat treatment and a second heat treatment performed sequentially; The first heat treatment has a heating rate of 3-5°C / min, an end point temperature of 750-850°C, and a holding time of 2-4h; The heating rate of the second heat treatment is 2-3°C / min, the end temperature is 900-1050°C, and the holding time is 3-6h; The cooling rate of the heat treatment is 5-10°C / min.

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