Method for recovering arsenic from complex gold ore by directional enrichment of arsenic in gold capture process

Abstract

The application relates to the field of clean extraction of complex gold-containing resources, in particular to a method for directional enrichment and recovery of arsenic in the process of gold capture of complex gold ore iron matte. The method first controls the arsenic content of the incoming material to be not less than 5% through material preparation, and when oxygen-controlled sulfidation smelting and gold capture are performed, arsenic is selectively volatilized into high-temperature flue gas, and then most of the arsenic in the flue gas is directly converted into a crude white arsenic product by using quenching technology, so that the separation process of arsenic is shortened; the rest of the arsenic is converted into arsenic-containing intermediate products such as high-arsenic dust, copper-arsenic slag and gypsum slag in subsequent links such as flue gas purification and acid making, and is returned to the preparation according to the needs of the sulfidation smelting, so that the closed loop and unified open outlet of arsenic in the system are formed, and efficient resource recovery of arsenic and near-zero discharge of hazardous waste in the whole process can be realized.

Description

Technical Field

[0001] This application relates to the field of metallurgical technology, specifically to a method for the targeted enrichment and recovery of arsenic in the gold extraction process of complex gold ore iron matte. Background Technology

[0002] With the continuous development of gold mineral resources, easily processed gold ore resources are becoming increasingly scarce, and high-arsenic complex sulfur gold concentrate has become an important raw material for gold extraction. This type of ore typically contains gold, silver, iron, sulfur, and various valuable metals and harmful elements such as arsenic, copper, lead, zinc, and antimony. It is characterized by complex mineral composition, close symbiotic relationships, and high arsenic content. Gold in this type of ore often exists in a microscopic state within sulfide minerals such as pyrite and arsenopyrite, resulting in a direct cyanide leaching rate typically below 50%. Traditional methods for processing high-arsenic gold concentrate mainly include oxidative roasting for arsenic removal-cyanide leaching and hydrometallurgical processes. While the oxidative roasting for arsenic removal-cyanide leaching process can effectively remove arsenic, the roasting process generates arsenic-containing dust and arsenic-containing waste gas, which is difficult and costly to treat and prone to secondary pollution. Furthermore, this process is lengthy, limiting gold recovery rates. Wet leaching processes (such as pressure oxidation and bacterial oxidation) are less effective at treating high-arsenic ores, resulting in incomplete arsenic fixation, high arsenic content in the leaching residue, and potential environmental pollution risks.

[0003] The existing copper matte gold extraction technology still faces the following technical challenges in the matte smelting process for treating complex gold-containing materials with high arsenic content: (1) Arsenic is dispersed in flue gas, copper matte, and smelting slag during the smelting process, and has not formed a good enrichment, separation, and open-loop recovery pathway, resulting in severe dispersion of arsenic in the system, with copper and arsenic not separated, forming a large amount of ineffective recycled materials, which affects the stability of the smelting process and the quality of the final product; (2) The separation of arsenic from valuable metals such as copper and gold is incomplete, resulting in a low direct recovery rate of copper and gold in the subsequent copper smelting and gold extraction process; (3) Arsenic-containing intermediate products cannot be effectively recycled, and there is no product output. The by-products of waste acid and waste electrolyte treatment, such as arsenic sulfide slag, black copper mud, and waste acid neutralization slag, are ultimately stored as arsenic-containing hazardous waste, and their disposal costs are high.

[0004] Iron matte gold extraction technology represents a new direction for processing complex high-arsenic sulfur gold concentrates. Unlike co-smelting technologies that rely on external metals, its core lies in fully utilizing the iron and sulfur elements inherent in the ore itself. Through endogenous component regulation and oxygen-controlled sulfidation smelting processes, gold-extracting iron matte is generated, efficiently recovering gold from the concentrate. However, due to the high arsenic and other impurities in the raw materials, how to cleanly and efficiently enrich and separate arsenic becomes a crucial aspect of the industrial application of iron matte gold extraction technology. To address this, while ensuring efficient gold extraction from iron matte, we propose an arsenic recovery method involving directional arsenic volatilization, cyclic enrichment, and rapid cooling of high-temperature flue gas to recover arsenic. This aims to produce crude arsenic products with reduced yields, achieve a stable arsenic open-circuit process, reduce arsenic dispersion, avoid ineffective arsenic material recycling, and form an economical, efficient, and stable industrial production model. Summary of the Invention

[0005] This invention aims to solve the problems existing in the prior art and provide a method for the targeted enrichment and recovery of arsenic in the complex gold mine matte process, which can achieve efficient separation and recovery of arsenic, comprehensive utilization of valuable metals, and closed-loop recycling of intermediate products. This method has high arsenic recovery rate, good gold capture effect, and is environmentally friendly.

[0006] To achieve the above objectives, the first aspect of this application provides a method for the targeted enrichment and recovery of arsenic in the complex gold mining process using iron matte, comprising the following steps:

[0007] (1) A mixture of high-arsenic complex sulfur-gold concentrate, slag-type modifier, pulverized coal, and arsenic-containing intermediate products is prepared to obtain a mixture, and the arsenic mass fraction of the mixture is controlled to be greater than 5%. The main chemical components (by mass content) of the high-arsenic complex sulfur-gold concentrate include: Au 5-100 g / t, Ag 100-500 g / t, Fe 15-35%, S 10-35%, SiO2 10-40%, CaO 1-10%, As 2-10%, and one or more of associated elements such as Cu, Pb, Zn, and Sb; the arsenic-containing intermediate product contains 5-40% As by mass, and one or more of associated Cu, Pb, Zn, and Sb. The arsenic mass content of the arsenic-containing intermediate product is 10-40%.

[0008] Preferably, the slag modifier is selected from at least one of quartz and limestone, the amount of slag modifier added is 5-20% of the mass of high-arsenic complex sulfur-gold concentrate, and the amount of pulverized coal added is 1-10% of the mass of high-arsenic complex sulfur-gold concentrate.

[0009] (2) Add the mixture to the smelting furnace and introduce oxygen-enriched air for controlled oxygen sulfidation smelting. Control the oxygen volume concentration in the oxygen-enriched air to be 40-90%, the inlet flow rate to be 3000-20000 Nm³ / h per ton of mixture under standard atmospheric pressure, and the smelting temperature to be 1200-1350℃. The smelting produces gold-capturing matte, high-temperature flue gas, and smelting slag.

[0010] Introducing oxygen-enriched air with a volume concentration of 40-90% provides sufficient oxidation intensity, allowing some sulfides to oxidize and release heat to maintain the smelting temperature, and promoting the efficient volatilization of arsenic into the flue gas. Simultaneously, by controlling the appropriate influx flow rate, sufficient stirring intensity in the molten pool can be ensured, promoting the aggregation and growth of matte droplets, while avoiding molten splashing and heat loss due to excessive flow.

[0011] At high temperatures, arsenic mainly undergoes the following reactions: 4FeAsS + 3O2 = 4FeS + 2As2O3 2FeAsS + 5O2 = Fe2O3 + As2O3 + 2SO2 2As2S3 + O2 = 2As2O3 + 6SO2 As₂O₃ + FeS = 2As + FeO + SO₂ 4As + O2 = 2As2O3 As₂O₃ + O₂ = As₂O₅ Preferably, a side-blown furnace is used as the matte smelting equipment. Oxygen-enriched air and pulverized coal are injected into the smelting furnace through its side-blown spray gun to promote the oxygen-controlled sulfidation smelting process. After smelting, the smelting slag is further subjected to heat preservation and sedimentation to achieve efficient separation of the iron matte phase from the smelting slag.

[0012] In the controlled-oxygen sulfidation smelting process, oxygen-enriched air and pulverized coal are injected into the melt through a side-blowing lance. The stirring effect generated by the gas injection enhances the mass and heat transfer of the melt and promotes multiphase reactions. By precisely controlling the ratio of oxygen-enriched air to pulverized coal, the oxidizing atmosphere of the smelting system can be controlled, avoiding the loss of gold and silver in the matte phase due to over-oxidation.

[0013] Preferably, the controlled Fe / SiO2 mass ratio of the smelting slag is 0.5-1.2, and the CaO / SiO2 mass ratio is 0.1-0.6. The appropriate amount of added calcium oxide helps reduce the viscosity and surface tension of the slag, thereby improving its fluidity, while also inhibiting the formation of Fe3O4 (magnetic iron) and avoiding the adverse conditions of "over-oxidation".

[0014] Preferably, the temperature of the heat preservation and settling process is controlled at 1200-1300℃ and the time is 40-60min. This operation allows the tiny iron matte droplets mixed in the slag to float, aggregate and settle back into the matte phase layer, thereby achieving efficient separation of the iron matte phase from the smelting slag and ensuring that the gold content in the smelting slag after separation is <0.5 g / t.

[0015] Preferably, the density difference between the iron matte phase and the smelting slag is ≥1.5 g / cm³, the interfacial tension difference is ≥200 mN / m, the FeS content in the iron matte phase is ≥70%, and the iron content of the gold-catching iron matte is 40-70%.

[0016] The main components of the gold-catching iron matte product include Au (20-250 g / t), Ag (200-800 g / t), Fe (40-70%), S (25-35%), and As (<1%).

[0017] (3) The high-temperature flue gas generated in step (2) is subjected to rapid cooling and arsenic removal and electrostatic precipitation treatment in sequence to obtain crude white arsenic and high arsenic flue gas respectively; the flue gas after electrostatic precipitation is subjected to washing, purification, conversion and absorption in sequence to obtain sulfuric acid and arsenic-containing waste acid.

[0018] Preferably, the temperature for rapid arsenic removal is 200-400 ℃, and the purity of the crude white arsenic is greater than 90%. By rapidly cooling the high-temperature flue gas to the range of 200-400 ℃, the selective separation of arsenic is achieved by utilizing the differences in the volatilization-condensation characteristics of different metal oxides (especially As2O3), thereby obtaining a crude white arsenic product with a purity >90%.

[0019] (4) The arsenic-containing waste acid is mixed with arsenic-containing dust generated by other smelting systems and subjected to acid leaching treatment. After separation, copper arsenic acid leaching solution and lead bismuth slag are obtained. Subsequently, the copper arsenic acid leaching solution is subjected to sulfidation treatment with gold-catching iron matte. After solid-liquid separation, gold-containing copper arsenic slag is obtained. The remaining liquid is neutralized to obtain gypsum slag.

[0020] In non-ferrous metal smelting systems, arsenic-containing dust and arsenic-containing waste acid are two types of hazardous waste that are extremely difficult to dispose of. For example, in the smelting of main metals such as copper and lead, the dust collection system generates a large amount of high-arsenic dust. Returning it to the original system would disrupt the stable operation of the main process; building a separate disposal line would be costly and complex to operate. This invention introduces such arsenic-containing dust from external systems as "raw material," allowing it to react with the arsenic-containing waste acid generated by this system. This not only achieves the synergistic treatment of two hazardous wastes from different sources but also provides an effective external source for the closed-loop recycling of arsenic, enhancing the enrichment and recovery of arsenic throughout the entire process.

[0021] Preferably, the arsenic-containing fumes generated by other smelting systems in the steps may include one or more of the fumes produced during copper, lead, and zinc smelting processes. The acid leaching treatment is carried out at a temperature of 80-95°C and a liquid-to-solid ratio of (3-6):1 L / kg. Under these conditions, most of the arsenic and copper in the arsenic-containing fumes can be leached out and concentrated in the acid leaching solution, while components such as lead and bismuth are concentrated in the leaching residue.

[0022] Preferably, the sulfidation treatment is carried out under conditions of 1.0-2.0 MPa pressure and 80-120℃ temperature. The pressurized environment significantly increases the solubility of hydrogen sulfide or sulfide ions in the solution, thereby promoting the full reaction of metal ions such as copper and arsenic to form sulfide precipitates such as CuS and As₂S₃, achieving efficient separation of copper and arsenic from other impurities in the solution. Under these conditions, a sufficient kinetic rate for the sulfidation reaction is ensured, while excessively high temperatures prevent the sulfide precipitates from dissolving or decomposing. Simultaneously, this helps reduce the corrosion risk of the autoclave, ensuring safe equipment operation.

[0023] (5) Take the high arsenic dust obtained in step (4), the gold-containing copper-arsenic slag and / or gypsum slag obtained in step (5) as the arsenic-containing intermediate products and return to step (1).

[0024] Preferably, the arsenic-containing intermediate product participating in the batching in step (1) accounts for 10-30% of the total mass of the mixture. In actual operation, the proportion of high-arsenic dust, copper-arsenic slag and gypsum slag and other materials needs to be specifically controlled according to the arsenic content of the high-arsenic complex sulfur-gold concentrate being processed, so as to ensure that the arsenic content in the final mixture is stable at more than 5%.

[0025] Compared with the prior art, the present invention has the following beneficial effects: (1) Internal circulation and resource utilization of arsenic-containing materials. This invention rapidly cools arsenic-containing high-temperature flue gas at 200-400℃, causing gaseous As2O3 to directly condense and crystallize, obtaining crude white arsenic product with a purity higher than 90%. The remaining arsenic forms intermediate products such as high-arsenic flue dust, gold-copper-arsenic slag, and gypsum slag in the subsequent acid production process, which are recycled as return materials in a closed loop within the system.

[0026] (2) Oxygen-controlled sulfidation smelting and endogenous regulation to achieve directional separation of arsenic. In the smelting process, this invention controls the high temperature of 1200-1350℃, introduces oxygen-enriched air with an oxygen volume concentration of 40-90%, and adds an appropriate amount of pulverized coal to achieve atmosphere regulation of "oxygen-controlled sulfidation". This aims to maximize the selective volatilization of arsenic into the flue gas in the form of As2O3, while effectively inhibiting its entry into the matte phase or slag phase.

[0027] (3) Near-zero discharge of hazardous waste throughout the entire process. This invention establishes a closed-loop cycle of arsenic within the system to achieve the coordinated disposal and resource utilization of self-produced and external arsenic-containing hazardous waste, fundamentally eliminating the discharge of hazardous waste. The entire process is clean and environmentally friendly. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A process flow diagram of a method for targeted enrichment and recovery of arsenic in a complex gold mine iron matte process provided in an embodiment of this application. Detailed Implementation

[0030] To facilitate understanding of this application, the following description will be more comprehensive and detailed in conjunction with the accompanying drawings and preferred embodiments, but the scope of protection of this application is not limited to the following specific embodiments.

[0031] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of this application.

[0032] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0033] Example 1: A method for targeted enrichment and recovery of arsenic in complex gold mine matte processes includes the following steps: (1) Batching: Take 1000 kg of high-arsenic complex sulfur gold concentrate, whose main chemical components by mass fraction are: Au 45 g / t, Ag 150 g / t, As 2.4%, S 25%, Fe 32%, SiO2 16%, Cu 0.8%, Pb 1.5%. Take 220 kg of arsenic-containing intermediate product generated by the system, whose arsenic mass content is 35%. Mix the two evenly, and the total arsenic mass fraction of the resulting mixture is 8.2%.

[0034] (2) Oxygen-controlled sulfurization smelting: The mixture obtained in step (1) is added to an oxygen-enriched side-blown smelting furnace. Oxygen-enriched air with a volume concentration of 65% is blown in, and the flow rate is controlled at about 15,000 Nm³ / h. At the same time, 46.4 kg of pulverized coal is added. The smelting temperature is controlled at 1250 ℃. The slag shape is adjusted by adding quartz sand and limestone, and the Fe / SiO2 mass ratio of the final slag is controlled at 1.2 and the CaO / SiO2 mass ratio is controlled at 0.5. After smelting, about 480 kg of gold-catching matte, about 710 kg of smelting slag and high-temperature flue gas are produced. The smelting slag is a general solid waste and can be used for building materials. The gold-catching matte is sent to subsequent cascade gold extraction. The composition of the gold-catching matte is: Au 128 g / t, Ag 420 g / t, Fe 60.2%, S 22.7%, As 0.8%. Calculations show that the gold recovery rate in iron matte is 98.5%.

[0035] (3) Flue gas treatment and arsenic recovery: The high-temperature flue gas at 1250 °C was rapidly cooled at 320 °C to obtain 76 kg of crude white arsenic with a purity of 92.5%; the flue gas was subjected to electrostatic precipitation to obtain 6 kg of high-arsenic flue dust, which was then purified and acidified to produce 98% sulfuric acid and about 1.8 m³ of arsenic-containing waste acid as a byproduct. The waste acid was leached with 50 kg of arsenic-containing flue dust (containing 10.5% Cu and 5.2% As) from the external system at 90 °C and a liquid-to-solid ratio of 4:1 for 3 hours. The leaching yielded about 12 kg of lead-bismuth slag and copper-arsenic acid leaching solution. The leaching solution was reacted with 60 kg of low-grade iron matte under high pressure at 1.5 MPa and 100 °C for 2 hours to separate about 25 kg of gold-containing copper-arsenic slag. After neutralization of the filtrate, about 18 kg of gypsum slag was obtained.

[0036] (4) Closed-loop circulation of arsenic: The high-arsenic flue dust, gold-copper-arsenic slag and gypsum slag generated in step (3) of this embodiment are all returned to the next batch of step (1) for batching, thus realizing the closed-loop circulation of arsenic in the system.

[0037] Example 2: A method for targeted enrichment and recovery of arsenic in complex gold mine matte processes includes the following steps: (1) Batching: Take 1000 kg of another high-arsenic complex sulfur-gold concentrate. Its main chemical components by mass fraction are: Au 38 g / t, Ag 180 g / t, As 3.5%, S 22%, Fe 28%, SiO2 20%, Cu 1.2%, Pb 2.5%, Zn 1.8%. Take 260 kg of arsenic-containing intermediate product circulating in the system. Its arsenic mass content is 38%. Mix the two evenly. The total arsenic mass fraction of the resulting mixture is 10.6%.

[0038] (2) Oxygen-controlled sulfidation smelting: The mixture obtained in step (1) is added to the smelting furnace. Oxygen-enriched air with an oxygen volume concentration of 70% is blown in, and 51.2 kg of pulverized coal is added at the same time. The smelting temperature is controlled at 1250 ℃. The slag shape is adjusted by adding a conditioning agent, and the Fe / SiO2 mass ratio of the final slag is controlled at 1.2 and the CaO / SiO2 mass ratio is controlled at 0.5. After smelting, about 450 kg of gold-catching matte, about 750 kg of smelting slag and high-temperature flue gas are produced. The smelting slag is a general solid waste and can be used for building materials. The gold-catching matte is sent to subsequent cascade gold extraction. The composition of the gold-catching matte is: Au 105 g / t, Ag 570 g / t, Fe 61.8%, S 20.5%, As 0.9%. The gold recovery rate in the matte is calculated to be 97.8%.

[0039] The subsequent steps are the same as steps (3) and (4) of Example (1), wherein the purity of the crude white arsenic obtained in step (3) is 93.2%.

[0040] Comparative Example 1: A method for targeted enrichment and recovery of arsenic in complex gold mine matte processes includes the following steps: This comparative example uses the same high-arsenic complex sulfur-gold concentrate as Example 1 as raw material. The only difference between this example and Example 1 is the batching step (1): no arsenic-containing intermediate products returned from the system are added. Apart from this, all other process conditions, including smelting temperature, oxygen-enriched air concentration, slag shape control, pulverized coal addition, and subsequent rapid quenching for arsenic removal and flue gas treatment, are completely consistent with Example 1. After rapid quenching for arsenic removal under the same conditions, the purity of the obtained crude white arsenic product decreased to 73%.

[0041] Because no arsenic-containing intermediates were returned, the arsenic mass fraction in the mixture was 2.4%, which is lower than 5%, resulting in a low concentration of As2O3 in the smelting flue gas and affecting the purity of the final crude white arsenic product.

[0042] The above are merely preferred embodiments of this application. It should be noted that this application is not limited to the above embodiments. For those skilled in the art, several improvements and modifications can be made without departing from the principles of this application. Any modifications, equivalent substitutions, improvements, etc., made within the methods and principles of this application should also be considered within the scope of protection of this application.

Claims

1. A method for the targeted enrichment and recovery of arsenic in the complex gold mining process of iron matte, characterized in that, Includes the following steps: (1) Mix high-arsenic complex sulfur gold concentrate, slag modifier, pulverized coal and arsenic-containing intermediate products to obtain a mixture with an arsenic mass fraction of not less than 5%; (2) Add the mixture to the smelting furnace, introduce oxygen-enriched air for controlled oxygen sulfidation smelting, and produce gold-catching iron matte, high-temperature flue gas and smelting slag; (3) The high-temperature flue gas in step (2) is first cooled down to convert the gaseous arsenic in the high-temperature flue gas into solid arsenic. Then, it is subjected to electrostatic precipitator and bag filter dust collection in sequence to obtain crude white arsenic product and high arsenic flue gas respectively. The flue gas after dust collection is washed, purified, converted and absorbed to produce sulfuric acid, and arsenic-containing waste acid is produced as a by-product. (4) Use the arsenic-containing dust generated by other smelting systems to treat the arsenic-containing waste acid produced in step (3). After solid-liquid separation, copper arsenic acid leaching solution and lead bismuth slag are obtained respectively. The copper arsenic acid leaching solution is subjected to sulfidation copper precipitation treatment with gold-catching iron matte. After solid-liquid separation, gold-containing copper arsenic slag is obtained. The remaining liquid is neutralized with lime to obtain gypsum slag. (5) Take the high arsenic dust obtained in step (3), the gold-containing copper-arsenic slag and gypsum slag obtained in step (4) as the arsenic-containing intermediate products and return to step (1).

2. The method for targeted enrichment and recovery of arsenic in the complex gold mine matte gold extraction process according to claim 1, characterized in that, In step (1), the high-arsenic complex sulfur-gold concentrate includes, by mass content: Au 5-100g / t, Ag 100-500g / t, Fe 15-35%, S 10-35%, SiO2 10-40%, CaO 1-10%, As 2-10%, and one or more of Cu, Pb, Zn, and Sb associated elements; the mass content of As in the arsenic-containing intermediate product is 5-40%; the slag modifier is selected from at least one of quartz and limestone, and its addition amount is 5-30% of the mass of the high-arsenic complex sulfur-gold concentrate; the addition amount of the pulverized coal is 1-10% of the mass of the high-arsenic complex sulfur-gold concentrate.

3. The method for targeted enrichment and recovery of arsenic in the complex gold mine matte gold extraction process according to claim 1, characterized in that, In step (2), the oxygen-controlled sulfurization smelting process controls the oxygen volume concentration of the oxygen-enriched air to be 40-90%, the oxygen-to-material ratio to be 50-130 Nm³ / t of the mixture, and the smelting temperature to be 1200-1350 ℃; the density difference between the iron matte phase and the smelting slag is ≥1.5 g / cm³, the interfacial tension difference is ≥200 mN / m, and the arsenic content is <1.0%; in the smelting slag formed by the oxygen-controlled sulfurization smelting, the Fe / SiO2 mass ratio is 0.5-1.2, and the CaO / SiO2 mass ratio is 0.1-0.

6.

4. The method for targeted enrichment and recovery of arsenic in the complex gold mine matte gold extraction process according to claim 1, characterized in that, The slag produced by smelting is subjected to heat preservation and sedimentation at a temperature of 1200-1300℃ for 30-60 minutes, so that the iron matte phase and the slag can be separated by gravity. The gold content in the slag is <0.5 g / t.

5. The method for targeted enrichment and recovery of arsenic in the complex gold mine matte gold extraction process according to claim 1, characterized in that, The temperature for rapid arsenic removal in step (3) is controlled at 200-400℃, and the purity of the crude white arsenic obtained is greater than 90%.

6. The method for targeted enrichment and recovery of arsenic in the complex gold mine matte gold extraction process according to claim 1, characterized in that, The arsenic-containing dust generated by other smelting systems in step (4) includes one or more of the dust generated during the smelting of copper, lead, and zinc; the process conditions for the acid leaching treatment are: temperature 80-95℃, liquid-to-solid ratio (3-6): 1 L / kg.

7. The method for targeted enrichment and recovery of arsenic in the complex gold mine matte gold extraction process according to claim 1, characterized in that, The pressure of the copper sulfide plating treatment in step (4) is 1.0-2.0 MPa and the temperature is 80-120 ℃.

8. The method for targeted enrichment and recovery of arsenic in the complex gold mine matte gold extraction process according to claim 1, characterized in that, The arsenic-containing intermediate product in step (1) accounts for 5-40% of the total mass of the mixture.

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