Method for treating micro-fine particle gold ore wrapped by bismuth sulfide

Abstract

The invention relates to a method for treating micro-fine particle gold ore wrapped by bismuth sulfide, and belongs to the technical field of precious metal and non-ferrous metal recovery. A method for treating bismuth sulfide wrapped micro-fine particle gold ore comprises the steps that bismuth gold ore powder containing bismuth sulfide and water are prepared into ore pulp, the ore pulp is mixed with a leaching agent, and the bismuth sulfide in the ore reacts to generate gaseous hydrogen sulfide, a solution containing bismuth ions and solid gold concentrate containing precious metal gold; collecting gaseous hydrogen sulfide, and reacting the gaseous hydrogen sulfide with the obtained solution containing bismuth ions to generate bismuth sulfide; and metal gold in the solid gold concentrate is extracted. According to the method, inorganic acid is adopted for gold and bismuth separation, bismuth mineral wrapping is opened, enriched gold minerals are released, then reaction conditions are changed through products of the inorganic acid for a regeneration reaction, in the process, bismuth concentrate is enriched and recycled, meanwhile, the gold and bismuth separation leaching agent is regenerated, the production cost is saved, and no waste is released in the reaction process.

Description

Technical Field

[0001] The invention relates to a method for processing bismuth sulfide-coated fine-grained gold ore, belonging to the technical field of precious metal and nonferrous metal recovery. Background Art

[0002] Gold (Au) and bismuth (Bi) are two important metal resources in bismuth gold mines. They are widely used in electronics, metallurgy, medicine and other fields. Gold is a precious metal with excellent conductivity and stability and is used in high-end electronic devices, while bismuth has a place in the pharmaceutical and chemical industries due to its low melting point and non-toxic properties. With the growing demand for these metals, how to efficiently, economically and resourcefully separate and recover gold and bismuth elements from bismuth-containing gold mines has become an important research topic.

[0003] The mineral composition of bismuth-gold ore is complex. Bismuth in the ore often exists in the form of bismuth sulfide, bismuth telluride and bismuth oxide, while gold is often embedded in the bismuth ore in the form of fine particles, flakes or lumps, which brings challenges to the recovery of gold. The traditional wet recovery process of bismuth-gold ore includes crushing, grinding, flotation, gravity separation, cyanide leaching and other steps to strip bismuth to achieve gold enrichment. Common methods for treating bismuth ores also include ferric chloride leaching-iron powder replacement method, ferric chloride leaching-diaphragm electrowinning method, ferric chloride leaching-hydrolysis bismuth precipitation method, chlorine selective leaching method, hydrochloric acid-nitrous acid leaching method, etc. These methods each have their own advantages and disadvantages. For example, although the ferric chloride leaching-iron powder replacement method has a high leaching rate, it has low environmental pollution, high material consumption, and large waste liquid discharge; the ferric chloride leaching-diaphragm electrolysis method can reduce the circulation and accumulation of iron ions in the process, but the control of electrode potential and the speed of solution passing through the diaphragm are relatively complicated; the ferric chloride leaching-hydrolysis bismuth precipitation method has large water and reagent consumption, low bismuth recovery rate, and large wastewater discharge; the chlorine selective leaching method eliminates the circulation and accumulation of a large number of iron ions in the process, but the consumption of chlorine is large, and part of the elemental sulfur will be further oxidized to sulfate, and the pollution and corrosion of chlorine are relatively serious; the hydrochloric acid-nitrous acid leaching method can increase the leaching rate of bismuth, but the impact on the environment cannot be ignored.

[0004] In order to solve the problems of traditional treatment processes, researchers have tried to develop new green wet recovery technologies, such as optimizing leaching conditions, developing new leaching agents, and introducing advanced separation technologies to improve the recovery efficiency of gold and bismuth and reduce environmental pollution. However, these methods often require high costs and have certain limitations in actual industrial applications.

[0005] The present invention aims to provide a new method for extracting gold from bismuth-gold ore by breaking bismuth, which can efficiently separate gold minerals from bismuth ores, thereby improving the leaching rate of gold, and also recovering leaching agents and bismuth minerals, thereby reducing production costs and environmental pollution. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide a method for treating bismuth sulfide-coated fine-grained gold ore, which can open the coating of bismuth minerals, release and enrich gold. At the same time, the innovative process route not only realizes the regeneration of leaching agent, but also realizes the gold-bismuth separation process without the generation of pollutants. More importantly, the present invention realizes the efficient separation of gold minerals and bismuth minerals, thereby achieving the purpose of improving the gold extraction rate of bismuth-gold ore.

[0007] A method for treating bismuth sulfide-coated fine-grained gold ore comprises the following steps: preparing bismuth-gold ore powder containing bismuth sulfide with water to form ore pulp, mixing the ore pulp with a leaching agent, so that the bismuth sulfide in the ore reacts to generate gaseous hydrogen sulfide, a solution containing bismuth ions and a solid gold concentrate containing metallic gold; collecting the gaseous hydrogen sulfide and subsequently reacting it with the obtained bismuth ion-containing solution to generate bismuth sulfide; and extracting the metallic gold in the solid gold concentrate.

[0008] In the above technical solution, it is preferred that the recovered gaseous hydrogen sulfide and fresh gaseous hydrogen sulfide react with the above obtained bismuth ion-containing solution to generate bismuth sulfide. The present invention uses the hydrogen sulfide recovered from the reaction to react with the bismuth ion-containing solution to obtain bismuth sulfide. When the recovered hydrogen sulfide is insufficient, fresh hydrogen sulfide can be supplemented according to the reaction needs.

[0009] In the above technical solution, it is preferred that the bismuth-gold ore powder is a powder with a particle size of 38-45 μm accounting for more than 90%, a bismuth grade of 10-20%, and a gold grade of 12-20 g / t.

[0010] In the above technical solution, it is preferred to add a gold extracting agent to the solid gold concentrate to extract gold and refine the gold product. The method of extracting the solid gold concentrate is the prior art in the art.

[0011] In the above technical solution, the leaching agent is preferably concentrated hydrochloric acid or sulfuric acid. Further, when sulfuric acid is selected as the leaching agent, it is used in combination with sodium chloride solution to prevent bismuth chloride from being hydrolyzed to form bismuth oxychloride precipitation.

[0012] A preferred technical solution of the present invention is: mixing bismuth-gold ore pulp with concentrated hydrochloric acid to obtain gaseous hydrogen sulfide, a mixed solution containing bismuth chloride and hydrogen sulfide, and a solid gold concentrate containing metallic gold; in a closed container, reacting the mixed solution containing bismuth chloride and hydrogen sulfide with the recovered gaseous hydrogen sulfide to obtain bismuth sulfide concentrate and hydrogen chloride solution.

[0013] Furthermore, a bismuth-gold ore slurry with a mass fraction of 5 to 30% is placed in a reactor, concentrated hydrochloric acid is added thereto, and a stirring reaction is carried out at -10 to 5°C, and the liquid-solid volume mass ratio is controlled to be 10:1 to 25:1. After reacting for 60 to 120 minutes, solid-liquid separation is quickly carried out to obtain gaseous hydrogen sulfide, a mixed solution containing bismuth chloride and hydrogen sulfide, and a solid gold concentrate containing metallic gold; the mixed solution containing bismuth chloride and hydrogen sulfide is transferred into a closed reactor, and gaseous hydrogen sulfide is introduced, and a stirring reaction is carried out at 20 to 80°C for 60 to 90 minutes to obtain a bismuth sulfide concentrate and a hydrogen chloride solution.

[0014] Another preferred technical solution of the present invention is: mixing bismuth-gold ore pulp with sulfuric acid solution until the pH value of the system is 0.5-1.5, and then adding a certain amount of sodium chloride thereto to obtain gaseous hydrogen sulfide, a mixed solution containing bismuth chloride and sodium sulfate, and a solid gold concentrate containing metallic gold; reacting the mixed solution containing bismuth chloride and sodium sulfate with calcium chloride to obtain solid gypsum and a mixed solution containing bismuth chloride and sodium chloride; in a closed container, reacting the mixed solution containing bismuth chloride and sodium chloride with recovered gaseous hydrogen sulfide to obtain bismuth sulfide concentrate and sodium chloride solution.

[0015] Further, a bismuth-gold ore pulp with a mass fraction of 5 to 30% is mixed with a sulfuric acid solution with a mass fraction of 50% until the pH value of the system is 0.5 to 1.5, and then sodium chloride is added thereto, and a stirring reaction is carried out at 50 to 90° C., wherein the molar amount of sodium chloride is 2 to 2.5 times that of sulfuric acid, and after reacting for 90 to 150 minutes, solid-liquid separation is quickly carried out to obtain gaseous hydrogen sulfide, a mixed solution containing bismuth chloride and sodium sulfate, and a solid gold concentrate containing metallic gold; the mixed solution containing bismuth chloride and sodium sulfate is reacted with a calcium chloride solution with a mass fraction of 20 to 30%, wherein the molar amount of calcium chloride is 1 to 1.2 times that of sulfuric acid, and the reaction is carried out at room temperature to obtain solid gypsum and a mixed solution containing bismuth chloride and sodium chloride; the mixed solution containing bismuth chloride and sodium chloride is transferred into a closed reactor, gaseous hydrogen sulfide is introduced, and a stirring reaction is carried out at 30 to 60° C. for 60 to 120 minutes to obtain a bismuth sulfide concentrate and a sodium chloride solution.

[0016] Preferably, the concentrated hydrochloric acid is a recovered hydrogen chloride solution or a recovered hydrogen chloride solution prepared by blending; the sodium chloride is a recovered sodium chloride solution or a recovered sodium chloride solution prepared by blending.

[0017] The beneficial effects of the present invention are as follows: the present invention uses inorganic acid to separate gold from bismuth, opens the bismuth mineral package, releases the enriched gold mineral, and then uses its own product to change the reaction conditions for regeneration reaction. In this process, not only bismuth essence is enriched and recovered, but also the gold-bismuth separation leaching agent is regenerated, which saves production costs, and no waste is released during the reaction process. More importantly, the implementation of the present invention can significantly improve the gold extraction rate of bismuth-gold mines, and achieve the unity of social benefits, economic benefits, and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the principle of the present invention;

[0019] Figure 2 This is a flow chart of the method for improving the gold leaching rate by treating bismuth-coated fine gold particles with concentrated hydrochloric acid as a leaching agent according to the present invention;

[0020] Figure 3 The present invention is a flow chart of a method for improving the gold leaching rate by treating bismuth-coated fine-grained gold using sulfuric acid as a leaching agent. DETAILED DESCRIPTION

[0021] The following non-limiting embodiments may enable a person skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0022] The test methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0023] Specific implementation method 1: (using concentrated hydrochloric acid as leaching agent)

[0024] A method for treating bismuth sulfide-coated fine-grained gold ore comprises the following steps:

[0025] (1) Gold-bismuth separation: a certain mass of bismuth-gold ore is mixed with water to form a slurry, the slurry is placed in a reactor, stirred and reacted at a certain temperature, and then a certain amount of leaching agent (36-38% concentrated hydrochloric acid) is added thereto, and the liquid-solid volume mass ratio is controlled to be 10:1-25:1. After reacting for 60-120 minutes, solid-liquid separation is performed rapidly to obtain gaseous hydrogen sulfide, gold concentrate and liquid phase 1. The obtained gold concentrate is sent to the gold extraction process, and the liquid phase 1 and gaseous hydrogen sulfide enter the regeneration process;

[0026] (2) gold extraction: adding a gold extraction agent to the gold concentrate obtained in step (1) to extract gold, extracting gold products and calculating the gold extraction rate;

[0027] (3) Regeneration: The liquid phase 1 obtained after separation of gold and bismuth and gaseous hydrogen sulfide are transferred into a closed reactor and stirred at a certain temperature. After 60 to 90 minutes of reaction, the reaction is terminated and solid-liquid separation is performed to obtain bismuth concentrate and liquid phase 2.

[0028] Furthermore, in step (1), the particle size of the bismuth-gold ore is 38-45 μm, accounting for more than 90%; the bismuth grade of the bismuth-gold ore is 10-20%, and the gold grade is 12-20 g / t;

[0029] Furthermore, the reaction temperature in step (1) is -10 to 5°C, and the stirring speed is 300 to 600 rpm;

[0030] Furthermore, the gold concentrate grade in step (1) is 25-40 g / t, and the liquid phase 1 is a mixture of bismuth chloride and hydrogen sulfide;

[0031] Furthermore, the gold extraction agent in step (2) is a conventional agent, such as sodium cyanide, sodium thiosulfate, golden cicada, etc.; the gold extraction method is a common gold extraction method, such as carbon-in-slurry gold extraction process, cyanide-zinc replacement process, pyrometallurgy, electrolysis, etc.;

[0032] Furthermore, the reaction temperature in step (3) is 20-80° C., and the stirring speed is 200-400 rpm.

[0033] Furthermore, the bismuth concentrate grade in step (3) is 25-35%; the liquid phase 2 is a hydrochloric acid solution, which can be used again in the bismuth-gold ore slurry preparation and gold-bismuth separation process in step (1).

[0034] The following examples are all based on Figure 2 The process shown in the figure is carried out, and the bismuth-gold ore used is mined from the same mining area, and the bismuth grade of the original ore is 10-20%, and the gold grade is 12-20 g / t.

[0035] Example 1

[0036] (1) Separation of gold and bismuth: 100 kg of bismuth-gold ore with a particle size of 38 to 45 μm and a proportion of 90% was mixed with 500 L of water to form a slurry, which was placed in a reactor and stirred at 300 rpm at 0°C. 500 L of concentrated hydrochloric acid was added, and the liquid-solid volume mass ratio was 10:1. After reacting for 60 minutes, solid-liquid separation was performed to obtain gaseous hydrogen sulfide, gold concentrate and liquid phase 1. The grade of the obtained slag phase gold concentrate was 30 g / t, and the liquid phase 1 was a mixture of bismuth chloride and hydrosulfuric acid.

[0037] (2) Gold extraction: The gold concentrate obtained in step 1 was subjected to gold extraction by cyanidation. The experimental process was as follows: First, the gold concentrate was mixed with water to a 30% slurry concentration, and 30 kg / t was added thereto. 矿 Calcium oxide, after alkali leaching for 3 hours, add 80kg / t 矿 The leaching of sodium cyanide was completed after 40 hours. After testing and calculation, it was found that the leaching rate of gold was 90.33%;

[0038] (3) Regeneration: The liquid phase 1 produced in the gold-bismuth separation process and gaseous hydrogen sulfide are transferred into a closed reactor and stirred at 200 rpm for 60 min at 20° C. After the reaction, solid-liquid separation is performed. The slag phase bismuth concentrate grade is 25%, and the liquid phase is a hydrochloric acid solution.

[0039] Comparative Example 1

[0040] The cyanide gold extraction test was directly carried out using the bismuth gold ore used in Example 1 as a raw material. The gold extraction test conditions were exactly the same as those in step 2, and the final gold leaching rate was 51.6%.

[0041] Example 2

[0042] (1) Separation of gold and bismuth: 100 kg of bismuth-gold ore with a particle size of 38 to 45 μm and a proportion of 95% was slurried with the hydrochloric acid solution obtained in the bismuth regeneration process of Example 1, placed in a reactor, stirred and reacted at 400 rpm at 5° C. without adding concentrated hydrochloric acid, and the liquid-to-solid volume mass ratio was 10:1. After reacting for 90 minutes, solid-liquid separation was performed to obtain gaseous hydrogen sulfide, gold concentrate and liquid phase 1. The grade of the obtained slag phase gold concentrate was 25 g / t, and the liquid phase 1 was a mixture of bismuth chloride and hydrosulfuric acid.

[0043] (2) Gold extraction: The gold concentrate obtained in step 1 was subjected to gold extraction by cyanidation. The experimental process was as follows: First, the gold concentrate was mixed with water to a 30% slurry concentration, and 30 kg / t was added thereto. 矿 Calcium oxide, after alkali leaching for 3 hours, add 80kg / t 矿 The leaching of sodium cyanide was completed after 40 hours. After testing and calculation, it was found that the leaching rate of gold was 88.53%;

[0044] (3) Regeneration: The liquid phase 1 produced in the gold-bismuth separation process and gaseous hydrogen sulfide are transferred into a closed reactor, stirred at 30° C. and 300 rpm for 75 min, and solid-liquid separation is performed after the reaction is completed. The slag phase bismuth concentrate grade is 30%, and the liquid phase is a hydrochloric acid solution.

[0045] Example 3

[0046] (1) Separation of gold and bismuth: 100 kg of bismuth-gold ore with a particle size of 38 to 45 μm and a proportion of 98% was slurried with the hydrochloric acid solution obtained in the bismuth regeneration process of Example 2, placed in a reactor, stirred and reacted at 500 rpm at -5°C, 500 L of concentrated hydrochloric acid was added, and the liquid-to-solid volume mass ratio was 15:1. After reacting for 120 min, solid-liquid separation was performed to obtain gaseous hydrogen sulfide, gold concentrate and liquid phase 1. The grade of the obtained slag phase gold concentrate was 35 g / t, and the liquid phase 1 was a mixture of bismuth chloride and hydrosulfuric acid.

[0047] (2) Gold extraction: The gold concentrate obtained in step 1 was subjected to gold extraction by cyanidation. The experimental process was as follows: First, the gold concentrate was mixed with water to a 30% slurry concentration, and 30 kg / t was added thereto. 矿 Calcium oxide, after alkali leaching for 3 hours, add 80kg / t 矿 Sodium cyanide was used for leaching, and the leaching was completed after 40 hours. After testing and calculation, it was found that the leaching rate of gold was 93.12%;

[0048] (3) Regeneration: The liquid phase 1 produced in the gold-bismuth separation process and gaseous hydrogen sulfide are transferred into a closed reactor and stirred at 40°C and 350 rpm for 80 min. After the reaction, solid-liquid separation is performed. The slag phase bismuth concentrate has a grade of 35%, and the liquid phase is a hydrochloric acid solution.

[0049] Example 4

[0050] (1) Separation of gold and bismuth: 100 kg of bismuth-gold ore with a particle size of 38 to 45 μm and a proportion of 96% was slurried with the hydrochloric acid solution obtained in the bismuth regeneration process of Example 3, placed in a reactor, and stirred at 500 rpm for reaction at -5°C without adding concentrated hydrochloric acid. The liquid-to-solid volume mass ratio was 15:1. After reacting for 120 minutes, solid-liquid separation was performed to obtain gaseous hydrogen sulfide, gold concentrate and liquid phase 1. The grade of the obtained slag phase gold concentrate was 30 g / t, and the liquid phase 1 was a mixture of bismuth chloride and hydrosulfuric acid.

[0051] (2) Gold extraction: The gold concentrate obtained in step 1 was subjected to gold extraction by cyanidation. The experimental process was as follows: First, the gold concentrate was mixed with water to a 30% slurry concentration, and 30 kg / t was added thereto. 矿 Calcium oxide, after alkali leaching for 3 hours, add 80kg / t 矿 The leaching of sodium cyanide was completed after 40 hours. After testing and calculation, it was found that the leaching rate of gold was 89.63%;

[0052] (3) Bismuth regeneration: The liquid phase 1 produced in the gold-bismuth separation process and gaseous hydrogen sulfide are transferred into a closed reactor and stirred at 40°C and 350 rpm for 80 min. After the reaction, solid-liquid separation is performed. The slag phase bismuth concentrate has a grade of 30%, and the liquid phase is a hydrochloric acid solution.

[0053] Example 5

[0054] (1) Separation of gold and bismuth: 100 kg of bismuth-gold ore with a particle size of 38 to 45 μm and a proportion of 94% was slurried with the hydrochloric acid solution obtained in the bismuth regeneration process of Example 4, placed in a reactor, stirred and reacted at 600 rpm at -10°C, and 500 L of concentrated hydrochloric acid was added. The liquid-to-solid volume mass ratio was 20:1. After reacting for 60 minutes, solid-liquid separation was performed to obtain gaseous hydrogen sulfide, gold concentrate and liquid phase 1. The grade of the obtained slag phase gold concentrate was 38 g / t, and the liquid phase 1 was a mixture of bismuth chloride and hydrosulfuric acid.

[0055] (2) Gold extraction: The gold concentrate obtained in step 1 was subjected to gold extraction by cyanidation. The experimental process was as follows: First, the gold concentrate was mixed with water to a 30% slurry concentration, and 30 kg / t was added thereto. 矿 Calcium oxide, after alkali leaching for 3 hours, add 80kg / t 矿 The leaching of sodium cyanide was completed after 40 hours. After testing and calculation, it was found that the leaching rate of gold was 95.71%;

[0056] (3) Regeneration: The liquid phase 1 and gaseous hydrogen sulfide produced in the gold-bismuth separation process are transferred into a closed reactor and stirred at 60°C and 350 rpm for 75 min. After the reaction, solid-liquid separation is performed. The slag phase bismuth concentrate grade is 35%, and the liquid phase is a hydrochloric acid solution.

[0057] Example 6

[0058] (1) Separation of gold and bismuth: 100 kg of bismuth-gold ore with a particle size of 38-45 μm and a proportion of 93% was slurried with the hydrochloric acid solution obtained in the bismuth regeneration process of Example 5, placed in a reactor, and stirred at 600 rpm for reaction at -10°C without adding concentrated hydrochloric acid. The liquid-to-solid volume mass ratio was 20:1. After reacting for 90 minutes, solid-liquid separation was performed to obtain gaseous hydrogen sulfide, gold concentrate and liquid phase 1. The grade of the obtained slag phase gold concentrate was 35 g / t, and the liquid phase 1 was a mixture of bismuth chloride and hydrosulfuric acid.

[0059] (2) Gold extraction: The gold concentrate obtained in step 1 was subjected to gold extraction by cyanidation. The experimental process was as follows: First, the gold concentrate was mixed with water to a 30% slurry concentration, and 30 kg / t was added thereto. 矿 Calcium oxide, after alkali leaching for 3 hours, add 80kg / t 矿 Sodium cyanide was used for leaching, and the leaching was completed after 40 hours. After testing and calculation, it was found that the leaching rate of gold was 92.07%;

[0060] (3) Regeneration: The liquid phase 1 produced in the gold-bismuth separation process and gaseous hydrogen sulfide are transferred into a closed reactor and stirred at 70°C and 300 rpm for 60 min. After the reaction, solid-liquid separation is performed. The slag phase bismuth concentrate grade is 30%, and the liquid phase is a hydrochloric acid solution.

[0061] Example 7

[0062] (1) Gold-bismuth separation: 100 kg of bismuth-gold ore with a particle size of 38-45 μm and a proportion of 92% was slurried with the hydrochloric acid solution obtained in the bismuth regeneration process of Example 6, placed in a reactor, stirred and reacted at 600 rpm at -5°C, and 500 L of concentrated hydrochloric acid was added. The liquid-to-solid volume mass ratio was 25:1. After reacting for 90 minutes, solid-liquid separation was performed to obtain gaseous hydrogen sulfide, gold concentrate and liquid phase 1. The grade of the obtained slag phase gold concentrate was 40 g / t, and the liquid phase 1 was a mixture of bismuth chloride and hydrosulfuric acid;

[0063] (2) Gold extraction: The gold concentrate obtained in step 1 was subjected to gold extraction by cyanidation. The experimental process was as follows: First, the gold concentrate was mixed with water to a 30% slurry concentration, and 30 kg / t was added thereto. 矿 Calcium oxide, after alkali leaching for 3 hours, add 80kg / t 矿 Sodium cyanide was used for leaching, and the leaching was completed after 40 hours. After testing and calculation, it was found that the leaching rate of gold was 98.01%;

[0064] (4) Regeneration: The liquid phase 1 and gaseous hydrogen sulfide produced in the gold-bismuth separation process are transferred into a closed reactor and stirred at 80°C and 400 rpm for 90 min. After the reaction, solid-liquid separation is performed. The slag phase bismuth concentrate grade is 35%, and the liquid phase is a hydrochloric acid solution.

[0065] Example 8

[0066] (1) Separation of gold and bismuth: 100k bismuth-gold ore with a particle size of 38-45 μm and a proportion of 92% was slurried with the hydrochloric acid solution obtained in the bismuth regeneration process of Example 7, and placed in a reactor. The mixture was stirred and reacted at 600 rpm at -5°C without adding concentrated hydrochloric acid. The liquid-to-solid volume mass ratio was 25:1. After reacting for 90 minutes, solid-liquid separation was performed to obtain gaseous hydrogen sulfide, gold concentrate and liquid phase 1. The grade of the obtained slag phase gold concentrate was 38 g / t, and the liquid phase 1 was a mixture of bismuth chloride and hydrosulfuric acid.

[0067] (2) Gold extraction: The gold concentrate obtained in step 1 was subjected to gold extraction by cyanidation. The experimental process was as follows: First, the gold concentrate was mixed with water to a 30% slurry concentration, and 30 kg / t was added thereto. 矿 Calcium oxide, after alkali leaching for 3 hours, add 80kg / t 矿 Sodium cyanide was used for leaching, and the leaching was completed after 40 hours. After testing and calculation, it was found that the leaching rate of gold was 96.92%;

[0068] (3) Regeneration: The liquid phase 1 produced in the gold-bismuth separation process and gaseous hydrogen sulfide are transferred into a closed reactor and stirred at 200 rpm for 60 min at 20° C. After the reaction, solid-liquid separation is performed. The slag phase bismuth concentrate grade is 25%, and the liquid phase is a hydrochloric acid solution.

[0069] Specific implementation method 2: (using sulfuric acid as leaching agent)

[0070] A method for treating bismuth sulfide-coated fine-grained gold ore comprises the following steps:

[0071] (1) Bismuth removal: bismuth-gold ore is mixed with water to form a slurry with a mass fraction of 5 to 30%, the slurry is placed in a reactor, and the reaction is carried out at 50 to 90° C., and then the pH value of the system is adjusted to 0.5 to 1.5 with 50% sulfuric acid by mass, and then a certain amount of sodium chloride is added thereto, and the reaction is stirred for 90 to 150 minutes, and then solid-liquid separation is carried out. The resulting slag phase is the gold concentrate, which can be used for gold extraction; the liquid phase is a bismuth complex salt solution 1, which is transferred to the sulfur recovery process; the hydrogen sulfide gas generated by the reaction is sent to a gas collection device;

[0072] Bi2S3+3H2SO4+6NaCl=2BiCl3+3H2S+3Na2SO4 (high temperature), H2S+2NaOH=Na2S+2H2O

[0073] (2) Recovery of sulfur: A certain amount of calcium chloride solution with a mass fraction of 20 to 30% is added to the bismuth double salt solution, and the mixture is stirred for reaction. After the reaction lasts for 30 to 60 minutes, the reaction is terminated and solid-liquid separation is performed. The resulting slag phase is gypsum, and the liquid phase is bismuth double salt solution 2, which is then transferred to the bismuth recovery process.

[0074] Na2SO4+CaCl2=CaSO4+2NaCl

[0075] (3) Recovering bismuth: The bismuth complex salt solution 2 and the solution in the gas collecting bottle are introduced into a bismuth recovery reactor, the reaction temperature is 30-60° C., the reaction is stirred for 60-120 minutes, and the reaction is terminated and solid-liquid separation is performed. The resulting slag phase is bismuth sulfide concentrate, and the liquid phase is sodium chloride solution. After the liquid phase is evaporated and concentrated, a concentrated sodium chloride solution and condensed water are obtained. The concentrated sodium chloride solution is returned to the bismuth removal process for repeated use, and the condensed water can be used for slurrying of bismuth-gold ore or preparing calcium oxide slurry.

[0076] 2BiCl3+3Na2S=Bi2S3+6NaCl

[0077] The above method uses sulfuric acid and sodium chloride to carry out bismuth removal reaction on bismuth gold ore to obtain gold concentrate, and the obtained gold concentrate is subjected to gold extraction by a cyanide gold extraction method, and the gold leaching rate can be increased to 90-95%; the added sulfuric acid is also converted into a gypsum product that can be sold, and the sodium chloride used in the bismuth removal can be regenerated and reused through an evaporation crystallization process, and the hydrogen sulfide generated in the bismuth removal process reacts with the sodium hydroxide in the gas collecting device to generate sodium sulfide, which is a reagent required for the bismuth recovery reaction.

[0078] Furthermore, in step (1), the particle size of the bismuth-gold ore is 38-45 μm, accounting for more than 90%; the bismuth grade of the bismuth-gold ore is 2-20%, and the gold grade is 5-20 g / t;

[0079] Furthermore, the molar ratio of the amount of sodium chloride added in step (1) to the amount of sulfuric acid added is 2 to 2.5 times, and the purpose of adding sodium chloride is to prevent bismuth chloride from hydrolyzing to form bismuth oxychloride precipitate;

[0080] Furthermore, in step (1), the stirring speed is 300-600 rpm, and the gas collecting bottle is filled with a sodium hydroxide solution with a mass fraction of 30%;

[0081] Furthermore, the gold concentrate grade in step (1) is 25-40 g / t, and the bismuth double salt solution 1 is a mixture of bismuth chloride and sodium sulfate;

[0082] Furthermore, in step (2), the molar ratio of the amount of calcium chloride added to the amount of sulfuric acid added is 1 to 1.2; the stirring speed is 200 to 400 rpm; and the bismuth double salt solution 2 is a mixture of bismuth chloride and sodium chloride.

[0083] Furthermore, the bismuth concentrate in step (3) has a grade of 25-35%.

[0084] Example 9

[0085] (1) Bismuth removal: bismuth-gold ore with a particle size of 45 μm and a proportion of 95% was mixed with water to form a 20% slurry, placed in a reactor, and reacted at 70°C. The pH was adjusted to 1.0 with 50% sulfuric acid, sodium chloride (molar ratio with sulfuric acid was 2.2) was added, and the solid-liquid separation was carried out after stirring for 120 minutes to obtain a gold concentrate with a grade of 30 g / t and a bismuth complex salt solution of 1. The H2S gas generated by the reaction was sent to a gas collector filled with 30% NaOH.

[0086] (2) Recovery of sulfur: Add 25% CaCl2 solution to the bismuth double salt solution 1, stir for 45 minutes, and separate the solid and liquid to obtain gypsum and bismuth double salt solution 2.

[0087] (3) Recovery of bismuth: The bismuth complex salt solution 2 is reacted with the Na2S solution in the gas collecting device at 45°C for 90 minutes, and after solid-liquid separation, a bismuth sulfide concentrate with a grade of 25% is obtained. The sodium chloride solution is evaporated and concentrated and then returned for use.

[0088] Example 10

[0089] (1) Bismuth removal: 90% bismuth-gold ore with a particle size of 40 μm was mixed with water to form a 15% slurry, placed in a reactor, and reacted at 80°C. The pH was adjusted to 0.8 with 50% sulfuric acid, sodium chloride (molar ratio with sulfuric acid was 2.0) was added, and the solid-liquid separation was carried out after stirring for 90 minutes to obtain a gold concentrate with a grade of 25 g / t and a bismuth complex salt solution of 1. The H2S gas generated by the reaction was sent to a gas collector filled with 30% NaOH.

[0090] (2) Recovery of sulfur: Add 30% CaCl2 solution to the bismuth double salt solution 1, stir for 50 minutes, and separate the solid and liquid to obtain gypsum and bismuth double salt solution 2.

[0091] (3) Recovery of bismuth: The bismuth complex salt solution 2 is reacted with the Na2S solution in the gas collecting device at 55° C. for 75 minutes. After solid-liquid separation, a bismuth sulfide concentrate with a grade of 27% is obtained. The sodium chloride solution is evaporated and concentrated and then returned for use.

[0092] Embodiment 11

[0093] (1) Bismuth removal: 30% slurry of bismuth-gold ore with a particle size of 38 μm and a proportion of 92% was prepared with water and placed in a reactor for reaction at 60°C. The pH was adjusted to 1.2 with 50% sulfuric acid, and sodium chloride (molar ratio to sulfuric acid was 2.3) was added. After stirring for 150 minutes, solid-liquid separation was performed to obtain a gold concentrate with a grade of 40 g / t and a bismuth complex salt solution of 1. The H2S gas generated by the reaction was sent to a gas collector filled with 30% NaOH.

[0094] (2) Recovery of sulfur: Add 20% CaCl2 solution to the bismuth double salt solution 1, stir for 40 minutes, and separate the solid and liquid to obtain gypsum and bismuth double salt solution 2.

[0095] (3) Recovery of bismuth: The bismuth complex salt solution 2 is reacted with the Na2S solution in the gas collecting device at 40° C. for 105 minutes, and after solid-liquid separation, a bismuth sulfide concentrate with a grade of 28.9% is obtained. The sodium chloride solution is evaporated and concentrated and then returned for use.

[0096] Example 12

[0097] (1) Bismuth removal: bismuth-gold ore with a particle size of 42 μm and a proportion of 91% was mixed with water to form a 10% slurry, placed in a reactor, and reacted at 85°C. The pH was adjusted to 0.9 with 50% sulfuric acid, sodium chloride (molar ratio with sulfuric acid was 2.1) was added, and the solid-liquid separation was carried out after stirring for 100 minutes to obtain a gold concentrate with a grade of 35 g / t and a bismuth complex salt solution of 1. The H2S gas generated by the reaction was sent to a gas collector filled with 30% NaOH.

[0098] (2) Recovery of sulfur: Add 25% CaCl2 solution to the bismuth double salt solution 1, stir for 35 minutes, and separate the solid and liquid to obtain gypsum and bismuth double salt solution 2.

[0099] (3) Recovery of bismuth: The bismuth complex salt solution 2 is reacted with the Na2S solution in the gas collecting device at 50° C. for 90 minutes. After solid-liquid separation, a bismuth sulfide concentrate with a grade of 33% is obtained. The sodium chloride solution is evaporated and concentrated and then returned for use.

[0100] Embodiment 13

[0101] (1) Bismuth removal: 90% bismuth-gold ore with a particle size of 39 μm was mixed with water to form a 25% slurry, placed in a reactor, and reacted at 75°C. The pH was adjusted to 1.1 with 50% sulfuric acid, sodium chloride (molar ratio to sulfuric acid was 2.4) was added, and the solid-liquid separation was carried out after stirring for 135 minutes to obtain a gold concentrate with a grade of 32 g / t and a bismuth complex salt solution of 1. The H2S gas generated by the reaction was sent to a gas collector filled with 30% NaOH.

[0102] (2) Recovery of sulfur: Add 28% CaCl2 solution to the bismuth double salt solution 1, stir for 55 minutes, and separate the solid and liquid to obtain gypsum and bismuth double salt solution 2.

[0103] (3) Recovery of bismuth: The bismuth complex salt solution 2 is reacted with the Na2S solution in the gas collecting device at 58° C. for 120 minutes. After solid-liquid separation, a bismuth sulfide concentrate with a grade of 31% is obtained. The sodium chloride solution is evaporated and concentrated and then returned for use.

[0104] Embodiment 14

[0105] (1) Bismuth removal: bismuth-gold ore with a particle size of 43 μm and a proportion of 93% was mixed with water to form a 5% slurry, placed in a reactor, and reacted at 65°C. The pH was adjusted to 0.7 with 50% sulfuric acid, sodium chloride (molar ratio with sulfuric acid was 2.5) was added, and the solid-liquid separation was carried out after stirring for 110 minutes to obtain a gold concentrate with a grade of 38 g / t and a bismuth complex salt solution of 1. The H2S gas generated by the reaction was sent to a gas collector filled with 30% NaOH.

[0106] (2) Recovery of sulfur: Add 22% CaCl2 solution to the bismuth double salt solution 1, stir for 48 minutes, and separate the solid and liquid to obtain gypsum and bismuth double salt solution 2.

[0107] (3) Recovery of bismuth: The bismuth complex salt solution 2 is reacted with the Na2S solution in the gas collecting device at 48° C. for 75 minutes. After solid-liquid separation, a bismuth sulfide concentrate with a grade of 30% is obtained. The sodium chloride solution is evaporated and concentrated and then returned for use.

[0108] Embodiment 15

[0109] (1) Bismuth removal: bismuth-gold ore with a particle size of 44 μm and a proportion of 92% was mixed with water to form a 12% slurry, placed in a reactor, and reacted at 90°C. The pH was adjusted to 1.3 with 50% sulfuric acid, sodium chloride (molar ratio with sulfuric acid was 2.0) was added, and the solid-liquid separation was carried out after stirring for 130 minutes to obtain a gold concentrate with a grade of 36 g / t and a bismuth complex salt solution of 1. The H2S gas generated by the reaction was sent to a gas collector filled with 30% NaOH.

[0110] (2) Recovery of sulfur: Add 29% CaCl2 solution to the bismuth double salt solution 1, stir for 60 minutes, and separate the solid and liquid to obtain gypsum and bismuth double salt solution 2.

[0111] (3) Recovery of bismuth: The bismuth complex salt solution 2 is reacted with the Na2S solution in the gas collecting device at 60° C. for 105 minutes, and after solid-liquid separation, a bismuth sulfide concentrate with a grade of 32.5% is obtained. The sodium chloride solution is evaporated and concentrated and then returned for use.

[0112] Example 16

[0113] (1) Bismuth removal: bismuth-gold ore with a particle size of 41 μm and a proportion of 95% was mixed with water to form a 18% slurry, placed in a reactor, and reacted at 55°C. The pH was adjusted to 0.6 with 50% sulfuric acid, sodium chloride (molar ratio with sulfuric acid was 2.2) was added, and the solid-liquid separation was carried out after stirring for 140 minutes to obtain a gold concentrate with a grade of 34 g / t and a bismuth complex salt solution of 1. The H2S gas generated by the reaction was sent to a gas collector filled with 30% NaOH.

[0114] (2) Recovery of sulfur: 21% CaCl2 solution was added to the bismuth double salt solution 1, and the mixture was stirred for 42 minutes to separate the solid and the liquid, thereby obtaining gypsum and the bismuth double salt solution 2.

[0115] (3) Recovery of bismuth: The bismuth complex salt solution 2 is reacted with the Na2S solution in the gas collecting device at 42°C for 85 minutes, and after solid-liquid separation, a bismuth sulfide concentrate with a grade of 35% is obtained. The sodium chloride solution is evaporated and concentrated and then returned for use.

Claims

1. A method for treating bismuth sulfide-coated fine-grained gold ore, comprising preparing bismuth-gold ore powder containing bismuth sulfide with water to form slurry, mixing the slurry with a leaching agent, so that the bismuth sulfide in the ore reacts to generate gaseous hydrogen sulfide, a solution containing bismuth ions and a solid gold concentrate containing precious metal gold; collecting the gaseous hydrogen sulfide and subsequently reacting it with the above-obtained bismuth ion-containing solution to generate bismuth sulfide; and extracting the metallic gold in the solid gold concentrate.

2. The method according to claim 1, characterized in that The bismuth-gold ore pulp is mixed with concentrated hydrochloric acid to obtain gaseous hydrogen sulfide, a mixed solution containing bismuth chloride and hydrogen sulfide, and a solid gold concentrate containing precious metal gold; in a closed container, the mixed solution containing bismuth chloride and hydrogen sulfide is reacted with the recovered gaseous hydrogen sulfide to obtain bismuth sulfide concentrate and hydrogen chloride solution.

3. The method according to claim 1, characterized in that The bismuth-gold ore pulp is mixed with a sulfuric acid solution until the pH value of the system is 0.5-1.5, and then a certain amount of sodium chloride is added thereto to obtain gaseous hydrogen sulfide, a mixed solution containing bismuth chloride and sodium sulfate, and a solid gold concentrate containing precious metal gold; the mixed solution containing bismuth chloride and sodium sulfate is reacted with calcium chloride to obtain solid gypsum and a mixed solution containing bismuth chloride and sodium chloride; in a closed container, the mixed solution containing bismuth chloride and sodium chloride is reacted with recovered gaseous hydrogen sulfide to obtain bismuth sulfide concentrate and a sodium chloride solution.

4. The method according to claim 1, characterized in that The recovered gaseous hydrogen sulfide is reacted with the above-obtained bismuth ion-containing solution to generate bismuth sulfide. If the amount is insufficient, fresh gaseous hydrogen sulfide can be added.

5. The method according to claim 2, characterized in that: A bismuth-gold ore slurry with a mass fraction of 5 to 30% is placed in a reactor, concentrated hydrochloric acid is added thereto, and a stirring reaction is carried out at -10 to 5°C, and the liquid-solid volume mass ratio is controlled to be 10:1 to 25:

1. After reacting for 60 to 120 minutes, solid-liquid separation is quickly carried out to obtain gaseous hydrogen sulfide, a mixed solution containing bismuth chloride and hydrogen sulfide, and a solid gold concentrate containing precious metal gold; the mixed solution containing bismuth chloride and hydrogen sulfide is transferred into a closed reactor, gaseous hydrogen sulfide is introduced, and a stirring reaction is carried out at 20 to 80°C for 60 to 90 minutes to obtain a bismuth sulfide concentrate and a hydrogen chloride solution.

6. The method according to claim 3, characterized in that: A bismuth-gold ore pulp with a mass fraction of 5-30% is mixed with a sulfuric acid solution with a mass fraction of 50% until the pH value of the system is 0.5-1.5, and then sodium chloride is added thereto, and stirred to react at 50-90° C., wherein the molar amount of sodium chloride is 2-2.5 times that of sulfuric acid, and after reacting for 90-150 minutes, solid-liquid separation is quickly performed to obtain gaseous hydrogen sulfide, a mixed solution containing bismuth chloride and sodium sulfate, and a solid gold concentrate containing precious metal gold; the mixed solution containing bismuth chloride and sodium sulfate is reacted with a calcium chloride solution with a mass fraction of 20-30%, wherein the molar amount of calcium chloride is 1-1.2 times that of sulfuric acid, and the reaction is carried out at room temperature to obtain solid gypsum and a mixed solution containing bismuth chloride and sodium chloride; the mixed solution containing bismuth chloride and sodium chloride is transferred into a closed reactor, gaseous hydrogen sulfide is introduced, and stirred to react at 30-60° C. for 60-120 minutes to obtain bismuth sulfide concentrate and a sodium chloride solution.

7. The method according to claim 1, characterized in that The bismuth-gold ore powder is a powder with a particle size of 38-45 μm accounting for more than 90%, a bismuth grade of 10-20%, and a gold grade of 12-20 g / t.

8. The method according to claim 1, characterized in that Add gold extracting agent to the solid gold concentrate to extract gold products.

9. The method according to claim 2 or 3, characterized in that: The concentrated hydrochloric acid is the recovered hydrogen chloride solution or the recovered hydrogen chloride solution after blending; the sodium chloride is the recovered sodium chloride solution or the recovered sodium chloride solution after blending.

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