A high-tin copper removal anode slime treatment method

Abstract

The application discloses a high-tin copper-removed anode slime treatment method. The method comprises the following steps: mixing the copper-removed anode slime with a tin content of 1-15 wt% with a reducing agent, a slagging agent and / or a sulfur-containing material to form a mixture; smelting the mixture in a reducing atmosphere; in the smelting process, the reducing agent reduces the high-valence tin oxide in the copper-removed anode slime into low-valence tin oxide, and reduces the sulfur in the sulfur-containing component of the copper-removed anode slime or the sulfur in the sulfur-containing material and the sulfur-containing component of the copper-removed anode slime into S 2‑ ; the S 2‑ reacts with the low-valence tin oxide to generate volatile tin sulfide and is removed at the same time, and the remaining S 2‑ forms a precious metal sulfide smelt with the precious metal and part of the lead and copper; and the slagging agent reacts with part of the lead oxide to form a silicate smelt slag.

Description

Technical Field

[0001] This invention belongs to the field of non-ferrous metal metallurgy and secondary resource recycling technology, specifically relating to a method for treating high-tin copper-removing anode mud based on matte smelting and volatilization detinning, which is particularly suitable for high-tin anode mud produced from secondary copper resource smelting such as electronic waste. Background Technology

[0002] Copper anode slime is an important byproduct of the electrolytic refining of crude copper. Rich in valuable elements such as gold, silver, selenium, tellurium, and platinum group metals, it is a key raw material for extracting rare and precious metals. Currently, the hydrometallurgical-pyrometallurgical combined process centered on the Kaldor furnace has become the mainstream technology for processing anode slime. This process typically involves obtaining copper-removed anode slime after hydrometallurgical copper removal, followed by reduction smelting. The basic principle is to use lead oxide or bismuth oxide as a collector, which, under the action of a reducing agent (such as carbon), reduces the collector metal to elemental lead or bismuth. These liquid metals have a strong dissolving ability for precious metals such as gold and silver, selectively capturing them from the complex slag phase to form precious metal-rich "precious lead" or "precious bismuth" alloys, achieving initial enrichment of precious metals. Subsequently, oxidative blowing removes the collector metals (lead, bismuth) and other impurities (such as copper, tellurium) through oxidative slag formation, ultimately obtaining a high-grade gold-silver alloy (Dol alloy).

[0003] However, with the expansion of secondary copper resource utilization, such as electronic waste, the tin content of the copper anode mud obtained after copper removal from smelting is as high as 1-15 wt%. When this high-tin copper anode mud enters the existing Kaldo furnace processing system, the tin mainly exists in the form of high-melting-point tin dioxide (SnO2, melting point approximately 1630℃). Under reducing smelting conditions, SnO2 is chemically stable and difficult to be fully reduced to metallic tin, and it is also difficult to form a low-melting-point eutectic slag phase with conventional silicate slag-forming agents. These unmelted SnO2 particles are dispersed throughout the slag phase (including the upper alkali metal sulfate slag and the lower lead silicate slag), increasing the viscosity and consistency of the slag. The high-viscosity slag severely hinders the settling, aggregation, and separation of high-density precious lead or precious bismuth alloy droplets, resulting in a large amount of precious metal being encapsulated or trapped in the slag, causing a decrease in recovery rate and making subsequent slag-gold separation difficult.

[0004] A search revealed that patent document CN110055421A discloses a pretreatment method for high-tin copper anode mud, comprising the following steps: (1) adding high-tin copper anode mud to water for stirring and washing to remove impurities in copper electrolyte, and separating the washing liquid and the washed high-tin copper anode mud; (2) returning the washing liquid to the copper electrolysis system and grinding the washed high-tin copper anode mud into anode mud powder; (3) subjecting the anode mud powder to acidic catalytic oxidation leaching, and separating the leaching liquid and leaching residue; (4) returning the leaching liquid to the electrolysis system to recover copper and nickel; and (5) using the leaching residue as a synthetic concentrate for recovering metallic tin. This method belongs to the wet treatment process of anode mud, which has the problems of long process and low recovery rate of precious metals and tin. Moreover, the tin-rich slag obtained in the published document has a complex composition, and a long process of extraction and separation is still required.

[0005] Therefore, the traditional Kaldor furnace process based on lead / bismuth capture faces core bottlenecks in treating high-tin anode slime, including deterioration of slag properties, poor metal settling and separation, and low precious metal recovery rates. Developing a new method that can specifically remove tin and improve precious metal capture efficiency is crucial for achieving efficient and clean utilization of high-tin copper-removed anode slime. Summary of the Invention

[0006] 1. The problem to be solved The present invention aims to provide a method for treating high-tin copper-removing anode sludge, which achieves selective removal of tin and efficient capture of precious metals through the synergistic effect of reduction-sulfidation-volatilization, thereby solving at least one of the problems in the prior art, such as high slag viscosity, difficulty in precious metal settling, and low recovery rate caused by high tin content.

[0007] 2. Technical Solution To solve the above problems, the technical solution adopted by the present invention is as follows: The first aspect of this invention provides a method for treating high-tin copper-removing anode sludge, comprising the following steps: The copper-removing anode mud with a tin content of 1-15 wt% is mixed with a reducing agent, a slagging agent and / or sulfur-containing materials to form a mixture. The mixture is smelted in a reducing atmosphere; During the smelting process, the reducing agent reduces high-valent tin oxides (such as SnO2) in the copper-removed anode mud to low-valent tin oxides (such as SnO), and reduces sulfur in the sulfur-containing components of the copper-removed anode mud itself, or sulfur in the sulfur-containing materials and the sulfur-containing components of the copper-removed anode mud itself, to sulfur. 2- The S 2- It reacts with low-valent tin oxides to form volatile tin sulfide, which is then removed, while the remaining S... 2- The precious metal matte phase, which forms sulfides with precious metals and some lead and copper, is used to capture precious metals; the slag-forming agent reacts with some lead oxides to form silicate slag.

[0008] The aforementioned precious metals include Au, Ag, and platinum group metals. The method of this invention is applicable to treating high-tin copper anode sludge with a tin content greater than 1 wt%, and particularly suitable for high-tin copper anode sludge with a tin content greater than 5 wt%, expanding the range of applicable raw materials for copper anode sludge treatment processes and effectively treating high-tin materials produced from the smelting of secondary resources such as electronic waste.

[0009] The equipment used in the above smelting steps includes, but is not limited to, tubular derivation furnaces, box / cavity smelting furnaces, vertical smelting furnaces, vacuum atmosphere smelting furnaces, and special continuous smelting furnaces. Among them, tubular derivation furnaces include tubular high-temperature smelting furnaces (SK2-4-14 single-temperature zone tubular furnace, SK2-6-14 extended tubular furnace, and vacuum tubular furnace STG-1400).

[0010] According to any embodiment of the first aspect of the present invention, the reducing agent is a carbonaceous reducing agent, which includes at least one of pulverized coal, coke, petroleum coke, and graphite. The amount of reducing agent added is 8% to 15% of the dry basis mass of the copper-removed anode mud, preferably 10% to 12%. This range of addition ensures sufficient reduction of high-valence tin oxides and sulfur while avoiding excessive reducing agent that would lead to raw material waste and increased flue gas pollutants.

[0011] According to any embodiment of the first aspect of the present invention, the sulfur-containing material includes at least one of elemental sulfur, pyrite, ferrous sulfide, sodium sulfate, and calcium sulfate; in addition, the sulfur-containing material is formed by the decomposition of lead sulfate contained in the copper-removing anode mud under the action of a reducing agent.

[0012] When the sulfur source of the copper-removing anode mud is insufficient and external sulfur-containing materials need to be added, the amount added should be such that the molar ratio of total sulfur to total tin in the mixture, S / Sn, is controlled between 3.0 and 8.0, preferably between 4.0 and 7.0, to ensure that S 2- It can react fully with low-priced tin oxides to remove tin, and also has a sufficient margin to form a stable noble metal matte phase with noble metals.

[0013] According to any embodiment of the first aspect of the present invention, the slag-forming agent is a silica-containing material, including at least one of quartz sand, silica, and glass powder. The amount of slag-forming agent added should be such that the slag composition satisfies a PbO / SiO2 mass ratio of 1.0-5.0. This ratio ensures that the slag-forming agent reacts fully with lead oxides to form a low-melting-point silicate slag, effectively improving the viscosity and fluidity of the slag.

[0014] According to any embodiment of the first aspect of the present invention, the melting temperature is 900°C to 1300°C and the melting time is 60 min to 180 min. This temperature range and time range can provide sufficient thermodynamic and kinetic conditions for a series of reactions such as reduction, sulfidation, volatilization and slag formation, ensuring that each reaction proceeds fully.

[0015] 1) When the temperature is below 900℃, the mixture cannot form a liquid phase, resulting in poor material flowability, hindered mass transfer reactions, and reduction of sulfur components to form sulfur. 2- The rate of S slows down, and S 2- Insufficient production and incomplete interphase reactions make it difficult for precious metals to fully form sulfides and enter the matte phase, resulting in a decrease in precious metal recovery rate.

[0016] 2) When the temperature is above 1300℃, in addition to tin sulfide, lead and copper sulfides / oxides and some low-boiling-point precious metal compounds will volatilize in large quantities along with the flue gas, causing the loss of main metals and precious metals and reducing the recovery rate; abnormal slag viscosity and system disorder: high temperature will aggravate slag overmelting, slag fluidity is too strong, and slag and matte are prone to mutual solubility, the two phases cannot be effectively separated, and it is difficult to achieve slag and matte separation.

[0017] In addition, at high temperatures, some sulfides undergo secondary decomposition and oxidation, which disrupt the established reaction system and further reduce the effectiveness of tin removal and precious metal capture. Metal volatilization surges, and the concentration of dust and metal components in flue gas increases significantly, leading to a sharp increase in pressure on downstream dust collection and exhaust gas treatment systems.

[0018] The tubular derivation furnace, box / cavity melting furnace, vertical melting furnace, vacuum atmosphere melting furnace and special continuous melting furnace used in this invention can not only provide the temperature required for heating, but also provide a reducing atmosphere.

[0019] According to any embodiment of the first aspect of the present invention, in the later stage of smelting, a mixture of reducing gas and air or oxygen is introduced into the melt for jet stirring, which can break the mass transfer boundary layer of the melt, promote the rapid volatilization of tin sulfide, and accelerate the sedimentation and separation of slag and precious metal matte phase, thereby improving the tin removal rate and the precious metal collection rate. The reducing gas is selected from natural gas, hydrogen, or carbon monoxide.

[0020] According to any embodiment of the first aspect of the present invention, the reducing gas is at least one of natural gas, carbon monoxide or hydrogen; when natural gas is used, the volume ratio of natural gas to oxygen is controlled to be 1:0.6 to 1.0, or the volume ratio of natural gas to air is controlled to be 1:2.8 to 4.8.

[0021] According to any embodiment of the first aspect of the present invention, the tin content in the slag and matte is monitored in real time during the stirring process, and stirring is stopped when the tin content in the slag is less than 0.5 wt% and the tin content in the matte is less than 0.05 wt%.

[0022] According to any embodiment of the first aspect of the present invention, the method further includes the steps of: collecting the flue gas generated during the smelting process and recovering tin sulfide from the flue gas. By capturing and converting tin sulfide into tin products through a flue gas treatment system, the resource recovery of tin is achieved, thereby improving resource utilization.

[0023] According to any embodiment of the first aspect of the present invention, the precious metal matte phase formed by the method of the present invention has an S content greater than 30%, a precious metal content greater than 25%, and a lead content greater than 20%. The matte phase has a high density and a large density difference with the slag, making it easy to achieve efficient separation from the slag. At the same time, the total amount of precious metals in the obtained slag is less than 100 ppm, which reduces the entrainment loss of precious metals in the slag and effectively improves the precious metal recovery rate.

[0024]

[0025] The second aspect of the present invention provides a precious metal matte phase obtained by a high-tin copper removal anode mud treatment method, wherein the precious metal matte phase has an S content greater than 30%, a precious metal content greater than 25%, and a lead content greater than 20%.

[0026] 3. Beneficial effects Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention utilizes the high volatility of SnS at the melting temperature and converts the high melting point SnO2, which is difficult to slag in the traditional process, into SnS through a reduction-sulfidation coupling reaction and removes it quickly by volatilization. This eliminates the adverse effect of tin on the viscosity of molten slag from the source and the tin removal effect is effective.

[0027] When processing tin-containing materials using existing metallurgical processes, tin is mostly present in the form of SnO2. SnO2 has a high melting point of 1630℃ and stable chemical properties, making it difficult to remove through conventional slag-forming reactions. Furthermore, SnO2 significantly increases the viscosity of slag. According to research, for every 1% increase in SnO2, the viscosity of slag increases by 15%-20%, leading to difficulties in slag-gold separation and low metal recovery rates.

[0028] Comparative analysis revealed that, for example, existing technologies (containing SnO2) have a slag viscosity of 1.96 Pa·s at 1200℃, resulting in poor fluidity; while the reduction coupling process (after Sn removal) reduces the slag viscosity to 0.85 Pa·s at 1200℃, a decrease of 70%-75%, effectively improving fluidity; viscosity is related to Sn content: when residual Sn < 0.05 wt%, the viscosity stabilizes below 0.5 Pa·s, improving slag-metal separation efficiency by 40%-50%.

[0029] (2) The slag phase after detinning in this invention is mainly composed of low-melting-point lead silicate and sulfate. The viscosity and consistency of the slag are reduced, and the fluidity is effectively improved, which is conducive to the sedimentation, aggregation and enrichment of precious metal droplets, and effectively reduces the entrainment loss of precious metals in the slag.

[0030] (3) This invention utilizes the thiophilic properties of noble metals to achieve selective removal of tin while simultaneously removing the remaining S² - It forms stable sulfide matte phases with precious metals and some lead and copper (such as Ag2S and Au dissolved in Cu-Pb-S matte), achieving efficient collection of precious metals; moreover, the precious metal matte phase has a high density, good separation effect from slag, and high precious metal collection rate.

[0031] (4) The method of the present invention can process high tin copper anode mud with Sn content of up to 5 wt%, and is especially suitable for high tin materials produced by secondary resource smelting such as electronic waste. It breaks through the limitation of traditional process on the tin content of raw materials and expands the applicable range of raw materials.

[0032] (5) The SnS volatilized by this invention can be efficiently captured and recovered as tin products in the flue gas treatment system, realizing the resource recovery of tin; there is no large amount of volatilization of harmful heavy metal lead during the process, the emission of flue gas pollutants is low, and at the same time, valuable metals such as precious metals, lead, and copper can also be effectively enriched and recovered, improving the overall level of clean production and the comprehensive utilization rate of resources. Attached Figure Description

[0033] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that these drawings are designed for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, unless specifically indicated, these drawings are intended only to conceptually illustrate the structural construction described herein and are not necessarily drawn to scale.

[0034] Figure 1 The results of thermodynamic calculations for the reduction sulfidation reaction of tin in the copper-removed anode mud of this invention; Figure 2 The XRD characterization spectrum of tin-containing materials collected from the flue dust of this invention; Figure 3 The results are SEM-EDS of the tin-containing products of this invention. Detailed Implementation

[0035] The following detailed description of exemplary embodiments of the invention is taken with reference to the accompanying drawings, which form part of the description and illustrate exemplary embodiments in which the invention may be practiced. While these exemplary embodiments have been described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be implemented and various changes may be made to the invention without departing from the spirit and scope thereof. The more detailed description of embodiments of the invention below is not intended to limit the scope of the claimed invention, but is merely illustrative and not restrictive of the description of the features and characteristics of the invention, to suggest the best mode for carrying out the invention, and is sufficient to enable those skilled in the art to practice the invention. Therefore, the scope of the invention is defined only by the appended claims.

[0036] The following detailed description and exemplary embodiments of the invention can be better understood in conjunction with the accompanying drawings, wherein the elements and features of the invention are identified by reference numerals.

[0037] The high-tin copper-removing anode sludge treatment method of the present invention includes the following steps: mixing copper-removing anode sludge with a tin content of 1-15 wt% with a reducing agent, a slagging agent and / or sulfur-containing materials to form a mixture; namely, copper-removing anode sludge: electrolytic anode sludge raw material after copper removal pretreatment, with a tin content range of 1-15% as the defined raw material boundary; The mixture is smelted under a reducing atmosphere; during the smelting process, the reducing agent reduces the high-valent tin oxide (SnO2) in the copper-removed anode mud to low-valent tin oxide (SnO), and reduces the sulfur in the sulfur-containing components of the copper-removed anode mud itself, or the sulfur in the sulfur-containing materials and the sulfur-containing components of the copper-removed anode mud itself, to sulfur. 2- ; The S 2- The tin sulfide is removed by reacting with low-valent tin oxides to form volatile tin sulfide. Thermodynamic calculation results are shown below. Figure 1 (The Gibbs free energy of the reaction SnO2 + C + SO2 = SnS + 2CO2) is as follows: Meanwhile, the remaining S... 2- The precious metal matte phase, which forms sulfides with precious metals and some lead and copper, is used to capture precious metals; the slag-forming agent reacts with some lead oxides to form silicate slag.

[0038] The aforementioned precious metal matte phase is a liquid eutectic formed by the high-temperature melting of sulfides; the precious metal matte phase refers to the liquid sulfide melt phase enriched with precious metals such as gold, silver, platinum, and palladium in a high-temperature smelting system.

[0039] By introducing reducing gas (CO / H2) and sulfiding agent (FeS2 / SO2), a coupled reaction system of reduction → sulfidation → volatilization is constructed. The core reactions are as follows: (1) Reduction reaction: SnO2 + CO → SnO + CO2 (800-900℃); (2) Sulfidation reaction: SnO + S 2-→SnS↑ (950-1100℃); (3) Volatilization removal: SnS has a boiling point of only 1230℃ and volatilizes rapidly in the gaseous state at the reaction temperature, and is captured by the dust collection system.

[0040] To ensure a complete reaction, the reducing agent, slagging agent, and sulfur-containing material mentioned above are all fine powder particles with a particle size between 100 and 500 mesh. If large particles are used for the reducing agent, slagging agent, and sulfur-containing material, there is a risk of incomplete reaction due to reaction coating.

[0041] The aforementioned precious metals include Au, Ag, and platinum group metals. The method of this invention is applicable to treating high-tin copper anode sludge with a tin content greater than 1 wt%, and particularly suitable for high-tin copper anode sludge with a tin content greater than 5 wt%. Extensive testing has revealed that when the tin content exceeds 5 wt%, the high viscosity of the slag leads to difficulties in slag-gold separation, thus expanding the applicable range of raw materials for copper anode sludge treatment processes and effectively treating high-tin materials produced from the smelting of secondary resources such as electronic waste.

[0042] Furthermore, the reducing agent is a carbonaceous reducing agent, including at least one of pulverized coal, coke, petroleum coke, and graphite. The amount of reducing agent added is 8% to 15% of the dry basis mass of the copper-removed anode mud, preferably 10% to 12%. This range of addition ensures sufficient reduction of high-valence tin oxides and sulfur while avoiding excessive reducing agent that would lead to raw material waste and increased flue gas pollutants.

[0043] Furthermore, the sulfur-containing material includes at least one of elemental sulfur, pyrite, ferrous sulfide, sodium sulfate, and calcium sulfate; in addition, the sulfur-containing material is formed by the decomposition of lead sulfate contained in the copper-removing anode mud under the action of a reducing agent.

[0044] When the sulfur source of the copper-removing anode mud is insufficient and external sulfur-containing materials need to be added, the amount added should be such that the molar ratio of total sulfur to total tin in the mixture, S / Sn, is controlled between 3.0 and 8.0, preferably between 4.0 and 7.0, to ensure that S 2- It can react fully with low-priced tin oxides to remove tin, and also has a sufficient margin to form a stable noble metal matte phase with noble metals.

[0045] Furthermore, the slag-forming agent is a silica-containing material, including at least one of quartz sand, silica, and glass powder. The amount of slag-forming agent added should ensure that the slag composition meets the PbO / SiO2 mass ratio of 1.0-5.0. This ratio can ensure that the slag-forming agent reacts fully with lead oxides to form a low-melting-point silicate slag, effectively improving the viscosity and fluidity of the slag.

[0046] Furthermore, the melting temperature is 900℃ to 1300℃, and the melting time is 60min to 180min. This temperature range and time range can provide sufficient thermodynamic and kinetic conditions for a series of reactions such as reduction, sulfidation, volatilization, and slag formation, ensuring that each reaction proceeds fully.

[0047] In the later stages of smelting, a mixture of reducing gas and air or oxygen is introduced into the melt for jet stirring, which can break the mass transfer boundary layer of the melt, promote the rapid volatilization of tin sulfide, and accelerate the sedimentation and separation of slag and precious metal matte phase, thereby improving the tin removal rate and precious metal capture rate.

[0048] The reducing gas is selected from natural gas, hydrogen, or carbon monoxide. The carbon monoxide is derived from CO enriched and recovered from the tail gas of blast furnace ironmaking, coking, and chemical synthesis (methanol, carbonyl synthesis). The hydrogen is derived from hydrogen extraction from the tail gas of chlor-alkali industry, refineries, synthetic ammonia, and coking units. The natural gas is derived from natural gas gases extracted from conventional oil and gas fields.

[0049] The method also includes the steps of collecting the flue gas generated during the smelting process and recovering tin sulfide from the flue gas. By capturing and converting tin sulfide into tin products through a flue gas treatment system, the resource recovery of tin is achieved, improving resource utilization.

[0050] The precious metal matte phase formed by the method of this invention has an S content greater than 30%, a precious metal content greater than 25%, and a lead content greater than 20%. This matte phase has a high density and a large density difference with the molten slag, making it easy to achieve efficient separation from the molten slag. Testing revealed that the density of the molten matte phase was 4500-5100 kg / m³, higher than that of the molten slag (3500-3800 kg / m³), with a density difference of 1000-1400 kg / m³. The matte was 25%-40% heavier than the slag. Under conditions of 1200℃ and slag viscosity of 0.5 Pa·s, the matte droplet settling velocity could reach 2-3 cm / s, enabling efficient separation of matte and slag within minutes.

[0051] Meanwhile, the total amount of precious metals in the obtained slag is less than 100 ppm, which reduces the loss of precious metals entrained in the slag and effectively improves the precious metal recovery rate.

[0052] Example 1 The copper-removed anode sludge processed in this embodiment is a product of secondary copper resource smelting from electronic waste. It has a tin content of 5.2 wt%, moisture content of 35%, D50 ≈ 5 μm, and all particles < 0.15 mm in diameter. This copper-removed anode sludge is used as raw material and processed according to the following steps: 1) Add petroleum coke as a reducing agent and elemental sulfur as an external sulfur-containing material at 10% of the dry weight of the copper-removed anode mud, so that the S / Sn molar ratio in the mixture is 4.0. Add quartz sand as a slagging agent to make the PbO / SiO2 mass ratio in the slag system 2.0. Mix the copper-removed anode mud, petroleum coke, elemental sulfur, and quartz sand thoroughly by mechanical stirring (the particle size of the calcined petroleum coke is 300 mesh, the particle size of the elemental sulfur is 100-200 mesh, and the particle size of the quartz sand is 300 mesh) to form a mixture. 2) The mixture was added to the SK2-4-14 smelting furnace. The oxygen probe EMF value was -2, and the smelting temperature was controlled at 1100℃. The viscosity of the slag was 2.04 Pa·s after sampling and testing using a Rigaku high-temperature melt viscometer from Japan, in accordance with YB / T185-2015 "Method for Determination of Viscosity of Blast Furnace Slag".

[0053] 3) During the smelting process, a mixed gas is jetted into the melt through a top-blown lance for stirring. The mixed gas is a mixture of natural gas and air, and the volume ratio of natural gas to air is controlled at 1:3.5. 4) Samples of slag and matte were taken every 20 minutes to test the tin content. When the tin content in the slag was below 0.5 wt% and the tin content in the matte was below 0.05 wt%, stirring was stopped. The viscosity of the slag was measured using a Rigaku high-temperature melt viscometer (Japan), and the viscosity was 0.43 Pa·s. In this embodiment, after stirring for 65 minutes, the Sn content in the slag was measured to be 0.48 wt% and the Sn content in the matte was measured to be 0.01 wt%, which met the stopping condition, and stirring was stopped immediately; the total melting time was 90 minutes. 5) Collect the flue gas generated during the smelting process and recover the tin sulfide from it through the flue gas treatment system; 6) After smelting, the precious metal matte phase and silicate slag are separated.

[0054] According to the test results, the tin removal rate in this embodiment was 98.5%, the S content in the precious metal matte phase was 32.1%, the precious metal content was 26.5%, the lead content was 22.3%, the total precious metal content in the slag was 85 ppm, and the precious metal recovery rate reached 99.2%.

[0055]

[0056] Example 2 The copper-removed anode mud treated in this embodiment has a tin content of 3.8 wt%, and is processed according to the following steps: 1) Add 12% of the dry weight of copper-removed anode mud as a reducing agent. The copper-removed anode mud itself provides a sulfur source through the decomposition of lead sulfate, so there is no need to add external sulfur-containing materials. Add silica as a slag-forming agent to make the mass ratio of PbO / SiO2 in the slag system 3.5. Mix all materials thoroughly to form a mixture. 2) The mixture was added to the SK2-4-14 smelting furnace. The oxygen probe EMF value was -2, and the smelting temperature was controlled at 1200℃. The viscosity of the slag was 1.96 Pa·s after sampling and testing using a Rigaku high-temperature melt viscometer from Japan, in accordance with YB / T185-2015 "Method for Determination of Viscosity of Blast Furnace Slag".

[0057] 3) During the smelting process, a mixed gas is injected into the melt through a top-blown spray gun for stirring. The mixed gas is a mixture of hydrogen and air, and the volume ratio of hydrogen to air is controlled to be 1:2.5. 4) Samples of slag and matte were taken every 20 minutes to test the tin content. When the tin content in the slag was below 0.5 wt% and the tin content in the matte was below 0.05 wt%, stirring was stopped. The viscosity of the slag was measured using a Rigaku high-temperature melt viscometer (Japan), and the viscosity was 0.48 Pa·s. In this embodiment, after stirring for 80 minutes, the Sn content in the slag was measured to be 0.42 wt% and the Sn content in the matte was measured to be 0.02 wt%, which met the stopping condition, and stirring was stopped immediately; the total melting time was 120 minutes. 5) Collect the flue gas and recover the tin sulfide contained therein; 6) The noble metal matte phase and silicate slag were separated.

[0058] According to the test results, the tin removal rate in this embodiment was 97.8%, the S content in the precious metal matte phase was 31.5%, the precious metal content was 25.8%, the lead content was 21.7%, the total precious metal content in the slag was 92 ppm, and the precious metal recovery rate reached 99.0%.

[0059] Example 3 The copper-removed anode mud treated in this embodiment has a tin content of 6.5 wt%, and is processed according to the following steps: 1) Add graphite as a reducing agent at 8% of the dry weight of copper-removed anode mud, add pyrite as an external sulfur-containing material to make the S / Sn molar ratio in the mixture 7.0, add glass powder as a slag-forming agent to make the PbO / SiO2 mass ratio in the slag system 5.0, and mix all materials thoroughly to form a mixture; 2) The mixture was added to the SK2-4-14 smelting furnace. The oxygen probe EMF value was -2, and the smelting temperature was controlled at 1300℃. The viscosity of the slag was 1.81 Pa·s after sampling and testing using a Rigaku high-temperature melt viscometer from Japan, in accordance with YB / T185-2015 "Method for Determination of Viscosity of Blast Furnace Slag".

[0060] 3) During the smelting process, a mixed gas is jetted into the melt through a top-blown spray gun for stirring. The mixed gas is a mixture of carbon monoxide and air, and the volume ratio of carbon monoxide to air is controlled to be 1:0.8. 4) Samples of slag and matte were taken every 15 minutes to test the tin content. When the tin content in the slag was below 0.5 wt% and the tin content in the matte was below 0.05 wt%, stirring was stopped. The viscosity of the slag was measured using a Rigaku high-temperature melt viscometer (Japan), and the viscosity was 0.47 Pa·s. In this embodiment, after stirring for 45 minutes, the Sn content in the slag was measured to be 0.39 wt% and the Sn content in the matte was measured to be 0.03 wt%, meeting the stopping condition, and stirring was stopped immediately; the total melting time was 60 minutes. 5) Collect the flue gas and recover the tin sulfide contained therein; 6) The noble metal matte phase and silicate slag were separated.

[0061] According to the test results, the tin removal rate in this embodiment was 98.2%, the S content in the precious metal matte phase was 33.0%, the precious metal content was 27.2%, the lead content was 23.0%, the total precious metal content in the slag was 78 ppm, and the precious metal recovery rate reached 99.3%.

[0062] Example 4 The copper-removed anode mud treated in this embodiment has a tin content of 2.5 wt%, and is processed according to the following steps: 1) Add coke as a reducing agent at 15% of the dry weight of copper-removed anode mud, add ferrous sulfide as an external sulfur-containing material to make the S / Sn molar ratio in the mixture 3.0, add a mixed slag-forming agent of quartz sand and silica to make the PbO / SiO2 mass ratio in the slag system 1.0, and mix all materials thoroughly to form a mixture; 2) The mixture was added to the smelting furnace. The oxygen probe EMF value was -2, and the smelting temperature was controlled at 1000℃. The viscosity of the slag was 2.37 Pa·s after sampling and testing using a Rigaku high-temperature melt viscometer from Japan, in accordance with YB / T185-2015 "Method for Determination of Viscosity of Blast Furnace Slag".

[0063] 3) During the smelting process, a mixed gas is injected into the melt through a top-blown lance for stirring. The mixed gas is a mixture of natural gas and oxygen, and the volume ratio of natural gas to oxygen is controlled at 1:0.9. 4) Samples of slag and matte were taken every 20 minutes to test the tin content. When the tin content in the slag was below 0.5 wt% and the tin content in the matte was below 0.05 wt%, stirring was stopped. The viscosity of the slag was measured using a Rigaku high-temperature melt viscometer (Japan), and the viscosity was 0.45 Pa·s. In this embodiment, after stirring for 140 minutes, the Sn content in the slag was measured to be 0.42 wt% and the Sn content in the matte was measured to be 0.01 wt%, which met the stopping condition, and stirring was stopped immediately; the total melting time was 180 minutes. 5) Collect the flue gas and recover the tin sulfide contained therein; 6) The noble metal matte phase and silicate slag were separated.

[0064] According to the test results, the tin removal rate in this embodiment was 97.2%, the S content in the precious metal matte phase was 30.5%, the precious metal content was 25.2%, the lead content was 20.8%, the total precious metal content in the slag was 96 ppm, and the precious metal recovery rate reached 98.9%.

[0065] Comparative Example 1 (without gas stirring) This comparative example illustrates the promoting effect of gas stirring on tin removal and precious metal capture.

[0066] The copper-removed anode sludge treated was exactly the same as in Example 1 (tin content 5.2 wt%), the mixture ratio was the same as in Example 1, the melting temperature was 1100℃, and the total melting time was 90 min. The difference was that no gas stirring was performed during the melting process.

[0067] After smelting, testing revealed a tin removal rate of 82.3%, a sulfur content of 22.1% in the precious metal matte phase, a precious metal content of 20.5%, a lead content of 17.6%, and a total precious metal content of 1050 ppm in the slag. The precious metal recovery rate was only 90.8%. This comparison demonstrates that jet stirring significantly improves both the tin removal rate and the precious metal recovery rate, while substantially reducing the loss of precious metals due to entrainment in the slag.

[0068] Extensive experiments have revealed that the aforementioned gas, under pressure, can enter the melt and form numerous microbubbles. These microbubbles rise, burst, and merge, generating localized turbulence. This turbulence breaks down the liquid layer boundaries of the melt, promoting the rapid volatilization of tin sulfide. Simultaneously, it accelerates the sedimentation and separation of slag and precious metal matte phases, improving tin removal and precious metal capture rates. Furthermore, it acts as a physical stirrer in the melt, rapidly rising vertically under buoyancy. During this rising process, it drags the surrounding liquid upwards, forming a mainstream rising zone, thus achieving the stirring effect.

[0069] The present invention and its embodiments have been described above illustratively, and this description is not restrictive. The accompanying drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, those skilled in the art, inspired by this description, may design similar structures and embodiments without departing from the spirit of the invention, and such designs should all fall within the protection scope of the present invention.

Claims

1. A method for treating high-tin copper-removing anode sludge, characterized in that, Includes the following steps: The copper-removed anode sludge is mixed with reducing agent, slagging agent and / or sulfur-containing materials to form a mixture; The mixture is smelted in a reducing atmosphere; During the smelting process, the reducing agent reduces the high-valence tin oxides in the copper-removed anode slime to low-valence tin oxides, and reduces the sulfur in the sulfur-containing components of the copper-removed anode slime itself, or the sulfur in the sulfur-containing materials and the sulfur-containing components of the copper-removed anode slime itself, to sulfur. 2- The S 2- It reacts with low-valent tin oxides to form volatile tin sulfide, which is then removed, while the remaining S... 2- The precious metal matte phase forms sulfides with precious metals and some lead and copper; the slag-forming agent reacts with some lead oxides to form silicate slag.

2. The method for treating high-tin copper-removing anode sludge according to claim 1, characterized in that, The reducing agent is a carbonaceous reducing agent, which includes at least one of pulverized coal, coke, petroleum coke, and graphite. The amount of reducing agent added is 8% to 15% of the dry weight of the copper-removed anode mud.

3. The method for treating high-tin copper-removing anode sludge according to claim 2, characterized in that, The amount of reducing agent added is 10% to 12% of the dry weight of the copper-removed anode mud.

4. The method for treating high-tin copper-removing anode sludge according to claim 1, characterized in that, Sulfur-containing materials include at least one of elemental sulfur, pyrite, ferrous sulfide, sodium sulfate, and calcium sulfate; the amount added should be such that the molar ratio of total sulfur to total tin in the mixture, S / Sn, is controlled between 3.0 and 8.

0.

5. The method for treating high-tin copper-removing anode sludge according to claim 4, characterized in that, The amount added should be such that the molar ratio of total sulfur to total tin in the mixture, S / Sn, is controlled between 4.0 and 7.

0.

6. The method for treating high-tin copper-removing anode sludge according to claim 1, characterized in that, The slag-forming agent is a material containing silica, including at least one of quartz sand, silica, and glass powder. The amount of slag-forming agent added should make the slag system composition satisfy the PbO / SiO2 mass ratio of 1.0-5.

0.

7. The method for treating high-tin copper-removing anode sludge according to claim 1, characterized in that, The melting temperature is 900℃ to 1300℃, and the melting time is 60min to 180min.

8. The method for treating high-tin copper-removing anode sludge according to claim 1, characterized in that, During the smelting process, a mixture of reducing gas and air or oxygen is introduced into the melt for jet stirring to provide heat and promote the rapid volatilization of tin sulfide.

9. The method for treating high-tin copper-removing anode sludge according to claim 8, characterized in that, The reducing gas is at least one of natural gas, carbon monoxide, or hydrogen; when natural gas is used, the volume ratio of natural gas to oxygen is controlled to be 1:0.6 to 1.0, or the volume ratio of natural gas to air is controlled to be 1:2.8 to 4.

8.

10. The method for treating high-tin copper-removing anode sludge according to claim 8 or 9, characterized in that, The tin content in the slag and matte is monitored in real time during the stirring process. Stirring is stopped when the tin content in the slag is below 0.5 wt% and the tin content in the matte is below 0.05 wt%.

Images