Process for the recovery of gold from gold-bearing barite and gold-bearing arsenopyrite, pyrite

Abstract

The application provides a method for recovering gold from gold-bearing barite and gold-bearing arsenopyrite / pyrite, and relates to the technical field of resource recycling. The method uses heavy-float combined stage crushing and grinding-stage separation to separate barite and arsenopyrite / pyrite, and then recovers gold from the two separated gold-bearing minerals. Gold-bearing barite is reduced by roasting and leaching to obtain leaching residue 1 and a solution rich in barium sulfide; gold-bearing arsenopyrite / pyrite is oxidized to remove arsenic under neutral conditions by using microbial flora separated from deep-sea hydrothermal sulfide deposits. After pretreatment, leaching residue 1 and leaching residue 2 are recovered by cyanidation-carbon pulp method. The method can recover gold from gold-coated gold in barite, replace traditional mine acid wastewater with microorganisms in deep-sea extreme environment, and take advantage of the characteristics of deep-sea microorganisms, such as stronger adaptability and milder leaching conditions, to provide a new path for efficient utilization of gold resources.

Description

Technical Field

[0001] This invention relates to the field of resource recycling technology, and in particular to a method for recovering gold from gold-loaded barite, gold-loaded arsenopyrite, and pyrite. Background Technology

[0002] Gold is a rare and precious metal with a brilliant luster and excellent stability. Throughout human history, it has served as both an important decorative element and a crucial component of monetary systems. In modern life and industry, leveraging its unique physicochemical properties, gold is frequently used in electronics, chemical catalysis, aerospace, and medical devices, making it a vital and scarce resource. However, while my country has a wide distribution and large reserves of gold mines, it suffers from a scarcity of high-grade deposits and a prevalence of associated and difficult-to-process gold deposits. As a non-renewable resource, gold is increasingly depleted through human exploitation. Therefore, the efficient development and utilization of complex gold mines has become a critical topic in global gold extraction research.

[0003] Pyrite and arsenopyrite are important gold-bearing minerals, while barite is considered a gangue mineral. In a gold mine in a certain province of my country, barite appeared as a gold-bearing mineral. Electron probe microanalysis of the actual minerals showed a gold grade of 0.5 g / t-3.4 g / t, indicating potential for recovery. The main gold-bearing minerals, pyrite and arsenopyrite, exhibit characteristics of being "poor, fine-grained, and mixed," with extremely fine grain sizes. Barite, due to its softness and tendency to become muddy, makes it impossible to effectively separate and enrich these two gold-bearing minerals using simple beneficiation methods, thus hindering the high-quality utilization of the resources.

[0004] Studies have shown that pyrite and arsenopyrite, which coat the surface of gold, are difficult to completely dissociate even with very fine grinding, resulting in extremely low direct cyanidation efficiency. For processing this type of gold ore, flotation pre-enrichment is commonly used first, followed by pretreatment of the gold concentrate using processes such as roasting oxidation, hot-pressing oxidation, biological oxidation, or chemical oxidation. This oxidizes the gold-coated pyrite or arsenopyrite, dissociating the gold, and the gold concentrated in the oxidation slag is then recovered using processes such as cyanidation. Microbial oxidation has advantages such as simple process, convenient operation, low equipment investment, low production costs, and minimal environmental pollution, making it a key research focus. However, microbial oxidation also faces challenges such as low reaction rate; low tolerance to arsenic and heavy metals; high requirements for gold ore raw materials; high gold content in cyanide slag; and the need to neutralize acidic wastewater, which limit its industrial application.

[0005] Compared to other gold-bearing minerals, barite has seen less research and industrial application as a gold-bearing mineral. Gold exists uniformly within barite in the form of fine-grained dispersive particles or lattice adsorption, resulting in low direct cyanidation efficiency. Therefore, gold-bearing barite requires pretreatment to release the encapsulated gold. Summary of the Invention

[0006] To address the technical problems of severe environmental pollution, low resource recovery rate, and complex process flow in existing technologies, this invention provides a method for recovering gold from gold-loaded barite and gold-loaded arsenopyrite and pyrite. This method is a synergistic recovery and utilization technology of coarse and fine-grained gold-loaded minerals, used to recover gold from gold mines containing gold-loaded coarse-grained barite and fine-grained arsenopyrite and pyrite, thereby achieving comprehensive utilization of gold mineral resources. The technical solution is as follows:

[0007] A method for recovering gold from gold-loaded barite and gold-loaded arsenopyrite / pyrite, the method comprising: S1. Crush the raw ore to obtain crushed products; S2. The crushed product obtained in S1 is fed into a gravity separation device to pre-dispose of tailings to obtain mixed concentrate and tailings fine mud. S3. The mixed concentrate obtained in S2 is coarsely ground to further dissociate the barite from the gold-sulfide intergrowth, and then gravity separation is performed to obtain gold-loaded barite and gravity separation tailings. S4. Combine the tailings obtained in S2 and the gravity separation tailings obtained in S3, grind them further, and then perform flotation to obtain pyrite / arsenic pyrite and flotation tailings. S5. Pyrolysis of biomass yields reducing gases; S6. The reducing gas obtained in S5 is introduced into the blast furnace to roast and reduce the gold-loaded barite obtained in S3. The blast furnace tail gas is absorbed and used to leach the roasted and reduced slag, finally obtaining a liquid rich in barium sulfide solution and gold-containing leaching slag 1. S7. After washing the gold-bearing pyrite / arsenic pyrite obtained in S4, perform microbial oxidation pretreatment under neutral conditions to obtain leaching residue 2. S8. The leaching residue 1 obtained in S6 and the leaching residue 2 obtained in S7 are combined, washed and slurried, and then cyanided to obtain the cyanided product. S9. After the cyanide product obtained in S8 is adsorbed with activated carbon to form a gold-cyanide complex, gold-loaded carbon and cyanide slag are obtained. After the gold-loaded carbon is desorbed and electrolyzed, the electrolyzed gold mud is smelted to obtain composite gold.

[0008] The raw ore in S1 is a complex associated mineral of gold-bearing barite and gold-bearing arsenopyrite / pyrite. The barite has a coarse grain size, while the arsenopyrite / pyrite has a fine grain size. The gold content of the gold-bearing minerals reaches the industrial boundary grade, with gold distributed in the gold-bearing minerals as fine-grained disseminated particles or lattice adsorption. 50%-90% of the raw ore is crushed to -2mm.

[0009] The gravity separation equipment in S2 is a jig, which utilizes the density differences of barite, arsenopyrite, pyrite gold, and most gangue to obtain a gravity-separated mixed concentrate. The barite recovery rate in the gravity-separated mixed concentrate is not less than 70%. The tailings slime is fine-grained slime containing some arsenopyrite, pyrite, and gangue.

[0010] In the S3 coarse grinding, the grinding fineness is controlled at -0.074mm, accounting for 50%-70%. The grinding in the stage separation stage is to prevent over-grinding, which would aggravate the barite mud phenomenon. The gravity separation equipment in S3 is a shaking table or spiral chute, and the recovery rate of gold-loaded barite concentrate is 80%-95%, with a grade of 85%-95%.

[0011] In the S4 process, the fine grinding requires that more than 80% of the minerals be -0.074mm to ensure sufficient mineral liberation. Copper sulfate is used as an activator in flotation, the pH of the flotation pulp is adjusted to 9-10 with lime, and the collector is a combination of amine black and butyl xanthate mixed in a mass ratio of 1:3-1:7. The gold grade in the gold-bearing pyrite / arsenic pyrite obtained in S4 is 15 g / t-25 g / t, with a recovery rate of 60%-80%. The flotation tailings obtained in S4 can be used as building aggregate and backfill material.

[0012] The biomass in S5 is one of straw, sawdust, walnut shells, corn cobs, and grain husks. The biomass particle size is less than 0.3 mm, and the mass ratio of biomass to gold-loaded barite obtained in S3 is 0.5:1 to 1:1. Generally, 2-4 pyrolysis devices are used in rotation.

[0013] The pyrolysis temperature in S5 is 600 ℃-950 ℃, the pyrolysis time is 20 min-45 min, and the resulting reducing gas is a mixture of CO, H2 and hydrocarbons.

[0014] The calcination reduction temperature in S6 is 750℃-1100℃, the calcination time is 1 h-3 h, and the gas flow rate of the reducing gas is 1.3 L / min-2.5 L / min; The roasting tail gas is absorbed by water, and the resulting tail gas absorbent is mixed with the roasting reducing slag for leaching. The roasting reducing slag has a particle size of 5-10 mm, the solid-to-liquid mass ratio is 20:1-80:1, the leaching temperature is 80℃-95℃, and the leaching time is 1 h-3 h. Tail gas absorption can reduce heating power consumption and create a weakly acidic environment to assist leaching. The obtained barium sulfide solution can be used as a raw material in the barium salt chemical industry.

[0015] In S7, the slurry concentration for microbial pre-oxidation is 15%-25%, the temperature is 2℃-80℃, the oxidation time is 5-7 days, the pH value is 2-10, and the aeration rate is 0.3m³. 3 / (m 3 ·h)-0.5 m 3 / (m 3 ·h); The microorganisms described are species isolated from deep-sea hydrothermal sulfide sediments, characterized by their tolerance to extreme temperatures, high salinity, and wide pH range. They mainly include sulfur-oxidizing bacteria such as *Thiomonas* and *Pseudomonas*, and neutrophilic iron-oxidizing bacteria such as *Marine Iron-oxidizing Bacteria*.

[0016] In step S8, tap water is used for 3-4 stages of countercurrent washing. After washing, lime is used to adjust the pH of the leaching residue solution to 10-11 before cyanidation.

[0017] The cyanidation process generally has no special requirements and can refer to general cyanidation schemes. In step S9, the gold-loaded carbon is desorbed and regenerated, then returned to activated carbon adsorption. The cyanide residue generated in the process can be used as building aggregate and backfill material. The activated carbon adsorption, activated carbon desorption and regeneration, electrolysis of the precious solution, and subsequent smelting steps in the method generally have no special requirements and can refer to conventional process conditions, adjusted according to actual conditions.

[0018] The aforementioned method addresses the unique geochemical characteristics of gold-bearing barite and gold-bearing arsenopyrite, employing a combined staged grinding, staged gravity separation, and flotation process to pre-separate barite and arsenopyrite, then recovering gold from each separately. It enriches gold in coarse-grained barite and recovers barium at high values, overcoming the chemical encapsulation of gold by arsenic under neutral conditions, and efficiently captures fine-grained gold-bearing barite and arsenopyrite. The neutral slag from both gold-bearing minerals is then uniformly incorporated into a cyanide leaching-carbonization process for gold recovery, establishing a technological paradigm for recovering gold from coarse-grained gold-bearing barite and fine-grained gold-bearing arsenopyrite.

[0019] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following: 1. Synergistic and Comprehensive Utilization of Gold-Carrying Barite and Gold-Carrying Arsine Pyrite and Pyrite Resources: This method fully utilizes the physicochemical properties of the minerals, employing gravity separation to obtain barite, followed by flotation to obtain arsine pyrite and pyrite. The two gold-carrying ores are then subjected to reduction roasting and microbial oxidation pretreatment, respectively, and the leaching residues from both are subjected to cyanide leaching. In addition to the target mineral gold, this invention also yields a valuable byproduct. The barium sulfide solution obtained from the leaching after reduction roasting is an important raw material for the barium salt industry. Using the barium sulfide solution as the main reaction medium, basic barium chemical products such as barium carbonate, various types of barium sulfate, and barium chloride, prepared from carbonates, sulfates, and hydrochloric acid, can be obtained. These barium products can be used in high-tech industries such as military, aerospace, electronic information, optical glass, and ceramics, thereby achieving comprehensive utilization of mineral resources. Unlike traditional gold ore beneficiation and barite beneficiation, this method, based on the physicochemical properties of the gold-carrying minerals, achieves efficient and comprehensive utilization of resources, synergistically completing the gold cyanide pretreatment and barite deep processing.

[0020] 2. Microbial pre-oxidation of gold-coated arsenopyrite and pyrite under neutral conditions, with microorganisms exhibiting strong environmental adaptability: Traditional microbial oxidation in gold mines takes place under acidic conditions, resulting in problems such as acidic wastewater treatment, equipment corrosion, low tolerance of microorganisms to arsenic and heavy metals, high requirements for gold ore raw materials, and the need for additional pH adjustment or washing steps for cyanidation. Microorganisms isolated from deep-sea hydrothermal sulfide sediments live at 2-4℃ and pH 6-8 on the seabed. During hydrothermal sulfide eruptions, seawater temperatures are around 80℃, and the pH of the sulfides is around 2.8, under which microbial metabolism is very vigorous. This invention utilizes the high activity of deep-sea microorganisms within a wide pH and temperature range to achieve biological pre-oxidation in a near-neutral environment. The process conditions are milder, reducing the complexity of subsequent pH adjustment, which is beneficial for improving equipment lifespan and applicability to different seasons and regions, as well as synergistic integration with subsequent cyanidation leaching processes. Furthermore, the characteristics of the deep sea—darkness, high pressure, high salinity, and extreme temperature differences—create strong adaptability for microorganisms in deep-sea hydrothermal sulfide sediments. These microorganisms not only have a wider operating temperature range, but also exhibit greater resistance to high salinity and heavy metal toxicity. Therefore, they hold promise for providing a new solution to the problem of low microbial tolerance in traditional microbial oxidation processes, improving overall process stability, and facilitating large-scale industrial applications.

[0021] 3. Combining biomass reduction roasting of gold-bearing barite with cyanide leaching to achieve full element recovery of barite minerals: Biomass resources are abundant, and improper handling can harm the environment, but proper treatment can transform them into a highly abundant sustainable clean resource. Utilizing the reducing gases such as CO, H2, and CH4 produced by biomass pyrolysis for reduction roasting is considered a feasible technology that helps achieve dual carbon targets and has been extensively studied. This invention utilizes the pyrolysis gas from biomass to replace the coke used in traditional barite reduction roasting, achieving cleaner production while saving resources. It is worth noting that there is a mismatch between the biomass pyrolysis gas generation rate and the roasting reaction, resulting in a certain amount of unreacted reducing gas in the roasting tail gas. Therefore, this invention leaches the roasting slag with an adsorbent solution from the roasting tail gas, saving energy and resources while creating a weak acid to accelerate leaching.

[0022] Through the above innovative combination, this invention aims to provide a complete technical solution that can not only efficiently recover gold from gold-bearing barite and gold-bearing ferroore and obtain high-value barium salt by-products, but also far surpasses existing technologies in terms of environmental impact and economic benefits, laying a solid foundation for the clean and sustainable development of resources in the future. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a flowchart of a method for recovering gold from gold-loaded barite and gold-loaded arsenopyrite, provided by an embodiment of the present invention. Detailed Implementation

[0025] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0026] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0027] In this embodiment of the invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0028] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0029] This invention provides a method for recovering gold from gold-loaded barite, gold-loaded arsenopyrite, and pyrite. For example... Figure 1 The flowchart shown illustrates a method for recovering gold from gold-loaded barite, gold-loaded arsenopyrite, and pyrite. This method may include the following steps:

[0030] S1. Crush the raw ore to obtain crushed products; S2. The crushed product obtained in S1 is fed into a gravity separation device to pre-dispose of tailings to obtain mixed concentrate and tailings fine mud. S3. The mixed concentrate obtained in S2 is coarsely ground to further dissociate the barite from the gold-sulfide intergrowth, and then gravity separation is performed to obtain gold-loaded barite and gravity separation tailings. S4. Combine the tailings obtained in S2 and the gravity separation tailings obtained in S3, grind them further, and then perform flotation to obtain pyrite / arsenic pyrite and flotation tailings. S5. Pyrolysis of biomass yields reducing gases; S6. The reducing gas obtained in S5 is introduced into the blast furnace to roast and reduce the gold-loaded barite obtained in S3. The blast furnace tail gas is absorbed and used to leach the roasted and reduced slag, finally obtaining a liquid rich in barium sulfide solution and gold-containing leaching slag 1. S7. After washing the gold-bearing pyrite / arsenic pyrite obtained in S4, perform microbial oxidation pretreatment under neutral conditions to obtain leaching residue 2. S8. The leaching residue 1 obtained in S6 and the leaching residue 2 obtained in S7 are combined, washed and slurried, and then cyanided to obtain the cyanided product. S9. After the cyanide product obtained in S8 is adsorbed with activated carbon to form a gold-cyanide complex, gold-loaded carbon and cyanide slag are obtained. After the gold-loaded carbon is desorbed and electrolyzed, the electrolyzed gold mud is smelted to obtain composite gold.

[0031] The following description, in conjunction with specific embodiments, illustrates this point.

[0032] Example 1 A gold ore mine in Shaanxi Province contains 3.2 g / t Au, 5.8% As, and 25% BaSO4. The gold content encapsulated in sulfides is as high as 61.24%, with approximately 20.18% being single or intercalated gold, and the remainder almost entirely gold encapsulated in barite. The barite particles range in size from 0.2 mm to 5 mm and exhibit good liberation. Using conventional methods to recover gold, the gold grade in the barite tailings is only 2.77 g / t, making recovery difficult and resulting in a low overall recovery rate. After crushing and grinding, the ore undergoes a jigging process, resulting in a 60% rejection rate of light gangue tailings. The jigged mixed concentrate is fed into the grinding system, and the ground material is separated by a spiral sluice, ultimately achieving a barite concentrate grade of 90.85% and a recovery rate of 87.25%. The tailings from the two gravity separation processes are then subjected to closed-circuit flotation with one roughing, three cleaning, and three scavenging stages.

[0033] Sawdust was used as the biomass raw material, with a sawdust to barite mass ratio of 0.7:1. The mixture was pyrolyzed at 800℃ for 30 minutes, with four pyrolysis units operating sequentially. The barite was roasted at 900℃ for 2 hours in a pyrolysis atmosphere, achieving a final barium conversion rate of 92.93%. The roasted residue was leached in a tail gas absorption liquid at 90℃ for 60 minutes, resulting in a BaS solution concentration of 49.6 g / L. The gold encapsulated in high-arsenic sulfides obtained from flotation was oxidized for 7 days at pH 7, 35℃, and a pulp concentration of 18%. After filtration, washing, and adjustment, cyanide leaching was performed, maintaining a sodium cyanide mass concentration of approximately 3 g / L and a solution pH of 10-11. The mixture was treated with alkaline solution for 1-2 hours, using 14 g / L of activated carbon at a liquid-to-solid volume ratio of 4:1 for 24 hours, with sodium hydroxide at a dosage of 12.5 kg / t gold concentrate.

[0034] The final gold leaching rate increased from 22.49% to 84.86%, and the cyanidation effect was significantly improved.

[0035] Example 2 A Canadian gold ore contains 3.2 g / t of Au. Sulfide-encapsulated gold accounts for a high 55.63%, with the remainder almost entirely composed of barite-encapsulated gold. The gold is distributed within the gold-bearing minerals in the form of fine-grained disseminated and lattice-adsorbed gold. Conventional beneficiation and cyanidation methods are only suitable for processing sulfide gold, resulting in a significant waste of barite-encapsulated gold.

[0036] After being crushed and ground to a density of -2mm (75%), the ore underwent two-stage jigging. The jigged concentrate was then finely ground to a density of -0.074mm (60%), and the ground material was separated into high-grade barite using a spiral sluice. The tailings from the two gravity separations were subjected to a roughing, cleaning, and scavenging flotation process, resulting in excellent enrichment of the gold-bearing ferrite. After enrichment, the gold grade was 20.07 g / t, with a recovery rate of 67.49%.

[0037] Using straw as biomass feedstock, with a straw-to-barite mass ratio of 0.85:1, the mixture was pyrolyzed at 750℃ for 30 minutes, with four pyrolysis units operating sequentially. The barite was then calcined at 900℃ for 2 hours in a pyrolysis atmosphere, achieving a final barium conversion rate of 90.86%. The calcined residue was leached using a tail gas absorbent at 95℃ for 90 minutes, with a liquid-to-solid ratio of 60:1 and a BaS solution concentration of 50.1 g / L. The gold encapsulated in high-arsenic sulfides obtained from flotation was oxidized for 5 days at pH 7.0, 37℃, and a pulp concentration of 15%. After filtration, washing, and pulp conditioning, the gold was leached by cyanide treatment.

[0038] The final gold leaching rate increased from 16.33% to 88.12%, successfully leaching the gold encapsulated in barite.

[0039] Example 3 In a shallow, low-temperature hydrothermal deposit in Guangxi, gold is associated with barite and arsenopyrite, with some gold encapsulated by barite. The total Au content is 3.5 g / t, and the As content is 2.2%. Some gold is distributed in the barite as intergranular gold and fine-grained disseminated gold. Barite acts as a gold-bearing mineral, closely associated with and encapsulating the gold.

[0040] After crushing and grinding, the ore is 72% concentrated in -2mm particles, followed by a jigging process. The jigging concentrate is then finely ground to 65% concentrated in -0.074mm particles. The finely ground minerals are fed into a shaking table for barite separation. The tailings from the two gravity separation processes undergo a roughing, cleaning, and scavenging flotation process, enriching the ore with gold-bearing pyrite and arsenopyrite. After flotation, the gold grade in the concentrate is 22.13 g / t, with a recovery rate of 68.11%.

[0041] Rice husks were used as biomass feedstock and pyrolyzed at 720℃ for 30 min. Barite enriched from the shaker concentrate was roasted at 1050℃ for 2 h in the pyrolysis gas of the rice husks, with a controlled gas flow rate of 2 L / min, achieving a final barium conversion rate of 89.14%. The roasted residue was leached in a tail gas absorption liquid at 95℃ for 75 min, resulting in a BaS solution concentration of 50.3 g / L. The gold encapsulated in high-arsenic sulfides obtained from flotation was oxidized for 5 days under conditions of pH 6.8, temperature 35℃, and pulp concentration of 17%.

[0042] After biological pre-oxidation, the ore and leaching residue 1 were combined for conventional cyanidation-carbon slurry process to recover gold. The final gold leaching rate increased from 18.88% to 86.96%, effectively recovering gold from barite.

[0043] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for recovering gold from gold-loaded barite and gold-loaded arsenopyrite / pyrite, characterized in that, The method includes: S1. Crush the raw ore to obtain crushed products; S2. The crushed product obtained in S1 is fed into a gravity separation device to pre-dispose of tailings to obtain mixed concentrate and tailings fine mud. S3. The mixed concentrate obtained in S2 is coarsely ground to further dissociate the barite from the gold-sulfide intergrowth, and then gravity separation is performed to obtain gold-loaded barite and gravity separation tailings. S4. Combine the tailings obtained in S2 and the gravity separation tailings obtained in S3, grind them further, and then perform flotation to obtain pyrite / arsenic pyrite and flotation tailings. S5. Pyrolysis of biomass yields reducing gases; S6. The reducing gas obtained in S5 is introduced into the blast furnace to roast and reduce the gold-loaded barite obtained in S3. The blast furnace tail gas is absorbed and used to leach the roasted and reduced slag, finally obtaining a liquid rich in barium sulfide solution and gold-containing leaching slag 1. S7. After washing the gold-bearing pyrite / arsenic pyrite obtained in S4, perform microbial oxidation pretreatment under neutral conditions to obtain leaching residue 2. S8. The leaching residue 1 obtained in S6 and the leaching residue 2 obtained in S7 are combined, washed and slurried, and then cyanided to obtain the cyanided product. S9. After the cyanide product obtained in S8 is adsorbed with activated carbon to form a gold-cyanide complex, gold-loaded carbon and cyanide slag are obtained. After the gold-loaded carbon is desorbed and electrolyzed, the electrolyzed gold mud is smelted to obtain composite gold.

2. The method for recovering gold from gold-loaded barite and gold-loaded arsenopyrite / pyrite according to claim 1, characterized in that, The raw ore in S1 is a complex associated mineral of gold-bearing barite and gold-bearing arsenopyrite / pyrite. The gold content of the gold-bearing minerals reaches the industrial boundary grade. The gold is distributed in the gold-bearing minerals in the form of fine-grained disseminated or lattice adsorbed particles. 50%-90% of the raw ore is crushed to -2mm.

3. The method for recovering gold from gold-loaded barite and gold-loaded arsenopyrite / pyrite according to claim 1, characterized in that, The gravity separation equipment in S2 is a jig, and the barite recovery rate in the mixed concentrate obtained by gravity separation is not less than 70%.

4. The method for recovering gold from gold-loaded barite and gold-loaded arsenopyrite / pyrite according to claim 1, characterized in that, In S3, the grinding fineness of the coarse grinding is controlled at -0.074mm, accounting for 50%-70%. The gravity separation equipment in S3 is a shaking table or spiral chute. The recovery rate of gold-loaded barite concentrate is 80%-95%, and the grade is 85%-95%.

5. The method for recovering gold from gold-loaded barite and gold-loaded arsenopyrite / pyrite according to claim 1, characterized in that, In the S4 process, the fine grinding requires that more than 80% of the minerals be -0.074mm to ensure sufficient mineral liberation. Copper sulfate is used as an activator in flotation, the pH of the flotation pulp is adjusted to 9-10 with lime, and the collector is a combination of amine black and butyl xanthate mixed in a mass ratio of 1:3-1:

7. The gold grade in the gold-bearing pyrite / arsenic pyrite obtained in S4 is 15 g / t-25 g / t, and the recovery rate is 60%-80%.

6. The method for recovering gold from gold-loaded barite and gold-loaded arsenopyrite / pyrite according to claim 1, characterized in that, The biomass in S5 is one of straw, sawdust, walnut shells, corn cobs, and grain husks. The biomass particle size is less than 0.3 mm, and the mass ratio of biomass to gold-loaded barite obtained in S3 is 0.5:1-1:

1. The pyrolysis temperature in S5 is 600 ℃-950 ℃, the pyrolysis time is 20 min-45 min, and the resulting reducing gas is a mixture of CO, H2 and hydrocarbons.

7. The method for recovering gold from gold-loaded barite and gold-loaded arsenopyrite / pyrite according to claim 1, characterized in that, The calcination reduction temperature in S6 is 750℃-1100℃, the calcination time is 1 h-3 h, and the gas flow rate of the reducing gas is 1.3 L / min-2.5 L / min; The roasting tail gas is absorbed by water, and the resulting tail gas absorption liquid is mixed with the roasting reduction residue for leaching. The roasting reduction residue has a particle size of 5-10 mm, the solid-to-liquid mass ratio is 20:1-80:1, the leaching temperature is 80℃-95℃, and the leaching time is 1 h-3 h.

8. The method for recovering gold from gold-loaded barite and gold-loaded arsenopyrite / pyrite according to claim 1, characterized in that, In S7, the slurry concentration for microbial pre-oxidation is 15%-25%, the temperature is 2℃-80℃, the oxidation time is 5-7 days, the pH value is 2-10, and the aeration rate is 0.3m³. 3 / (m 3 ·h)-0.5 m 3 / (m 3 ·h); The microorganisms are bacterial species isolated from deep-sea hydrothermal sulfide sediments, including *Thiomonas*, *Pseudomonas*, and *Marine Iron Oxidizers*.

9. The method for recovering gold from gold-loaded barite and gold-loaded arsenopyrite / pyrite according to claim 1, characterized in that, In step S8, tap water is used for 3-4 stages of countercurrent washing. After washing, lime is used to adjust the pH of the leaching residue solution to 10-11 before cyanidation.

10. The method for recovering gold from gold-loaded barite and gold-loaded arsenopyrite / pyrite according to claim 1, characterized in that, The gold-loaded carbon in S9 is desorbed and then regenerated, returning to activated carbon for adsorption.

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