A method for separating gold and copper flotation mixed concentrate

Abstract

The present invention belongs to the field of mineral processing, and specifically relates to a method for separating mixed concentrates of gold and copper flotation, comprising the following steps: (1) breaking hydrophobic floccules of mixed concentrates of gold and copper flotation; (2) eliminating organic matter in the solution to keep the aqueous solution clean; (3) preliminary pre-separation of mixed concentrates of gold and copper flotation; (4) grinding and dissociation of some gold and copper conjoined bodies; (5) conveying the slurry of step (4) to a hydrocyclone for classification; (6) purifying the rough gold concentrate and recovering some chalcopyrite; (7) conveying the gold concentrate slurry of step (6) to a sedimentation tank for sedimentation, and the obtained gold concentrate (natural gold particles) can be directly purified and refined; copper concentrate I, copper concentrate II and copper concentrate III are conveyed to a dehydration system composed of a thickener and a filter for dehydration, and qualified copper concentrate is used as a raw material for smelting and extracting copper, and a small amount of gold contained in the copper concentrate can be recovered. The present invention can separate mixed concentrates of gold and copper to obtain gold and copper concentrates with stable indicators and reliability.

Description

Technical Field

[0001] The invention belongs to the field of ore dressing, and in particular relates to a method for separating gold and copper flotation mixed concentrates. Background Art

[0002] Ore dressing is a process of separating useful minerals from useless or harmful minerals in mineral raw materials by physical or chemical methods, or separating multiple useful minerals. It is also called "mineral processing". The product with enriched useful components is called concentrate, and the product with enriched useless components is called tailings. The concentrate provided by ore dressing is mainly used as raw material for extracting metals in the smelting industry. Magnetic separation is a method of separating useful minerals from minerals based on the different magnetic properties of minerals. High-gradient magnetic separators are effective in processing fine-grained paramagnetic minerals, especially for separating weak magnetic iron ore. With the development of science and technology, there is a potential possibility of using high-gradient magnetic separators in the recovery and separation of non-ferrous metal sulfide ores or oxide ores. For the separation of mixed concentrates of gold and copper, the methods currently used in ore dressing include gravity separation, amalgam gold extraction, cyanide gold extraction, and flotation separation. In gold processing plants, gravity separation is mainly used to separate coarse and fine gold from ores. In addition to the size of gold particles, the geometric shape and structure of gold particles also affect the gravity separation effect. Generally, most gold particles are flaky after grinding. The surface of small flaky gold particles is hydrophobic and light, so they will float on the water surface and be lost in the light product chalcopyrite, resulting in a low gold recovery rate. In the amalgamation gold extraction method, fine gold particles with a particle size of less than 0.03 mm are easy to be lost with the slurry, and the mercury on the mercury plate is not suitable for forming amalgam, which reduces the recovery rate. At the same time, when dealing with mercury paste, mercury vapor evaporates and is prone to poisoning. In the cyanide gold extraction method, harmful elements such as copper, sulfur, and iron in copper ore cause a sharp drop in recovery rate, and the dosage of sodium cyanide also increases sharply. Sodium cyanide is highly toxic and has a significant impact on the environment. In the flotation separation method, natural gold and chalcopyrite are similar in floatability, and the selectivity of collectors and inhibitors to them is similar. Their separation is a difficult problem, and there is no example at present. Therefore, for gold and copper flotation mixed concentrates, seeking scientific and effective treatment methods is the key to solving existing problems. Summary of the invention

[0003] In order to overcome the problems of low recovery rate of copper and gold, high production cost, high toxicity of reagents and environmental pollution in the existing gold and copper flotation mixed concentrate separation method, a separation and treatment method is provided which can effectively improve the recovery rate of gold and copper, reduce production cost and reduce environmental pollution.

[0004] A method for separating mixed concentrates of gold and copper by flotation, (1) Breaking down the hydrophobic floccules of mixed concentrates of gold and copper by flotation: The mineral particles obtained by flotation are hydrophobic. When the particles come into contact, the particles will flocculate due to the hydrophobic force on the surface. This situation occurs between different mineral particles, making it difficult to separate them from each other. Therefore, this situation must be eliminated during separation. In this case, sodium sulfide is used to desorb the hydrophobic agent adsorbed on the surface of gold and copper minerals, but sodium sulfide can only desorb about 65% of the agent on the surface of the mineral. At the same time, sodium sulfide is a strong alkaline substance. Excessive use and high pH value affect the adsorption and catalytic performance of activated carbon, so it must be strictly controlled during use. Based on this, research has shown that the addition of ethanol or butanol can completely desorb the agent adsorbed on the surface of gold and copper particles into the solution. Ethanol or butanol is a heteropolar molecule. It has both lipophilic and hydrophilic properties. Therefore, it has an attraction with hydrophobic organic matter and water molecules. It can dissolve hydrophobic organic matter in aqueous solution and cooperate with sodium sulfide to completely desorb the reagents adsorbed on the surface of gold particles and copper minerals, and eliminate the flocs generated by different mineral particles. The gold and copper mixed concentrate obtained by flotation and a certain amount of clean water are transported to the 1# mixing barrel, and a mixture of sodium sulfide and ethanol is added for stirring. The slurry mass concentration is 50%, the amount of sodium sulfide is 1.5~2.6kg / t, and the amount of ethanol (purity above 95%) is 1.3~2.4kg / t. The gold particles and chalcopyrite flocs are separated and kept dispersed;

[0005] (2) Eliminate organic matter in the solution to keep the aqueous solution clean (without hydrophobic organic matter):

[0006] Organic matter in the solution will affect the recycling of water and cause gold and copper particles to flocculate again, affecting subsequent treatment operations, so it must be completely eliminated. Activated carbon is a porous substance with relatively developed internal pores and a large specific surface area. Its surface has a strong adsorption capacity for organic matter. At the same time, it can enrich oxidants in the solution and has the characteristics of catalytic oxidation of substances adsorbed on the surface, so the solution can be kept clean (without hydrophobic organic matter). The slurry that has completed the above step (1) is transported to the 2# mixing barrel and activated carbon is added for stirring. The amount of activated carbon used is 3.2~3.6kg / t, which can quickly adsorb and catalytically oxidize the organic flotation agent in the solution to keep the solution clean;

[0007] (3) Preliminary pre-separation of gold and copper flotation mixed concentrate:

[0008] Add clean water to the slurry after completing the above step (2), and then transport the adjusted slurry to the Nelson gold concentrator to enrich the natural gold particles, perform preliminary separation of gold and copper, and obtain gold rough concentrate and copper concentrate I. The control parameters of the Nelson gold concentrator are: -200 mesh content accounts for 65%, feed concentration is 40%, and the expanded gravity multiple is 60 times;

[0009] (4) Grinding and dissociation of some gold and copper conjoined bodies:

[0010] The gold concentrate after the above step (3) is transported to the vertical stirred mill for grinding. The grinding medium is a mixture of ceramic balls and stainless steel balls in a certain ratio (4:1). The mill liner is a rubber liner to prevent the surface of the gold particles from being magnetized. The mass concentration of the feed to the vertical stirred mill is 50%.

[0011] (5) The slurry after the above step (4) is transported to the hydrocyclone for classification, and the qualified particles with a particle size of -0.043 mm account for 80% (overflow), and the coarse particles (sand) are returned to the ball mill for re-grinding. The mass concentration of the cyclone feed is 50%, the feed pressure is 0.12MPa, and the overflow mass concentration is 25%.

[0012] (6) Purification of gold concentrate and recovery of some chalcopyrite:

[0013] The slurry with a concentration of 25% after completing the above step (5) is transported to a high-gradient strong magnetic field magnetic separator system to enrich the chalcopyrite to obtain copper concentrate II, copper concentrate III and gold concentrate (natural gold particles). The process is divided into two stages, including a roughing selection and a scavenging selection. The control parameters are: the roughing selection background field strength is 1.2T, the scavenging selection background field strength is 1.4T, the pulse number is 300r / min, the flow rate is 3cm / s, and the load ratio is 0.25.

[0014] (7) The gold concentrate (natural gold particles) slurry obtained in step (6) is transported to a sedimentation tank for sedimentation, and the copper concentrate I obtained in step (3) and the copper concentrate II and copper concentrate III obtained in step (6) are transported to a dehydration system consisting of a thickener and a filter for dehydration. The gold concentrate (natural gold particles) finally obtained can be directly purified and refined, and the qualified copper concentrate can be used as a raw material for smelting and copper extraction, and the small amount of gold contained in the copper concentrate can be recovered.

[0015] The preparation system comprises: a 1# stirring barrel, a 2# stirring barrel, a Nelson gold selector, a 1# pump tank, a vertical stirring mill, a hydraulic cyclone, a 1# ore pump, a 2# pump tank, a 2# slurry pump, a 1# high gradient strong magnetic field magnetic separator, a 2# high gradient strong magnetic field magnetic separator, a sedimentation tank, a thickener, and a ceramic filter. The discharge port of the 1# stirring barrel is connected to the feed port of the 2# stirring barrel through a pipeline, the discharge port of the 2# stirring barrel is connected to the feed port of the Nelson gold selector, the concentrate discharge port of the Nelson gold selector discharges gold coarse concentrate, and the tailings discharge port of the Nelson gold selector discharges copper concentrate I;

[0016] The concentrate discharge port of the Nelson gold concentrator enters the 1# pump pool, which is connected to the upper feed port of the hydraulic cyclone through the 1# ore pump, and the bottom flow port at the lower end of the hydraulic cyclone is connected to the feed port of the vertical stirring mill through a pipeline, and the discharge port of the vertical stirring mill is connected to the 1# pump pool, and the overflow port at the upper end of the hydraulic cyclone is connected to the 2# pump pool, and the 2# pump pool is connected to the feed port of the 1# high gradient strong magnetic field magnetic separator through the 2# slurry pump, and the concentrate discharge port of the 1# high gradient strong magnetic field magnetic separator is connected to the feed port of the 2# high gradient strong magnetic field magnetic separator, and the concentrate discharge port of the 2# high gradient strong magnetic field magnetic separator is connected to the sedimentation tank, and the material precipitated at the bottom of the sedimentation tank is gold concentrate; the tailings discharge port of the 1# high gradient strong magnetic field magnetic separator, the tailings discharge port of the 2# high gradient strong magnetic field magnetic separator, and the tailings discharge port of the Nelson gold concentrator are connected to the thickener, and the discharge port of the thickener passes through the ceramic filter and the filter residue is copper concentrate;

[0017] The first stirring barrel is added with a mixture of sodium sulfide and ethanol; the second stirring barrel is added with activated carbon;

[0018] The grinding medium in the vertical stirred mill is a mixture of ceramic balls and stainless steel balls, and the mill liner is a rubber liner;

[0019] The field strength of the 1# high gradient strong magnetic field magnetic separator is 1.2T; the field strength of the 2# high gradient strong magnetic field magnetic separator is 1.4T.

[0020] The specific process is:

[0021] With regard to the shortcomings of the prior art, the technical problems solved by the present invention are:

[0022] 1) When using gravity separation, the small flake-shaped gold particles are hydrophobic and light, so they will float on the water surface and be lost in the light product chalcopyrite, resulting in a low gold recovery rate;

[0023] 2) When using the amalgamation gold extraction method, fine gold particles with a particle size of less than 0.03 mm are easy to be lost with the ore pulp, and are not easy to form amalgam with mercury on the mercury plate, which reduces the recovery rate. At the same time, when handling mercury paste, mercury vapor evaporates and is easy to cause poisoning;

[0024] 3) When using the cyanide gold extraction method for separation, harmful elements such as copper, sulfur, and iron in chalcopyrite cause the recovery rate to drop sharply, and the amount of sodium cyanide also increases sharply. Sodium cyanide is highly toxic and has a significant impact on the environment;

[0025] 4) When flotation is used for separation, gold and chalcopyrite have similar floatability, and collectors and depressants have similar selectivity for them. It is difficult to separate gold from chalcopyrite by flotation of gold to suppress copper or by flotation of copper to suppress gold.

[0026] The present invention can separate gold and copper mixed concentrates to obtain gold and copper concentrates with stable indicators and reliability, and solves the problem that natural gold and chalcopyrite have similar floatability, collectors and inhibitors have similar selectivity for them, and are difficult to collect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A process flow of separation method for gold and copper flotation mixed concentrate

[0028] Figure 2 Equipment connection diagram of a method for separating mixed concentrates of gold and copper by flotation

[0029] Among them, 1—1# mixing barrel (sodium sulfide + ethanol) 2—2# mixing barrel (activated carbon); 3—Nielsen gold separator; 4—1# pump tank; 5—vertical stirring mill; 6—hydraulic cyclone; 7:1# ore pump; 8—2# pump tank; 9—2# slurry pump; 10—1# high gradient strong magnetic field magnetic separator; 11—2# high gradient strong magnetic field magnetic separator; 12 sedimentation tank; 13—thickener; 14—ceramic filter. DETAILED DESCRIPTION

[0030] like Figure 1 A method for separating a mixed concentrate of gold and copper by flotation is shown, comprising the following steps:

[0031] (1) Destruction of hydrophobic flocs in mixed gold and copper flotation concentrates:

[0032] The gold and copper mixed concentrate obtained by flotation and a certain amount of clean water are transported to the 1# stirring barrel, and a mixture of sodium sulfide and ethanol is added for stirring. The slurry mass concentration is 50%, the amount of sodium sulfide is 1.5~2.6kg / t, and the amount of ethanol is 1.3~2.4kg / t. The gold particles and chalcopyrite flocs are separated and kept dispersed;

[0033] (2) Eliminate organic matter in the solution to keep the aqueous solution clean:

[0034] The slurry after the above step (1) is transported to the 2# mixing tank, and activated carbon is added and stirred for 15 minutes; the amount of activated carbon used is 3.2~3.6kg / t;

[0035] (3) Preliminary pre-separation of gold and copper flotation mixed concentrate:

[0036] Add clean water to the slurry after completing the above step (2), and transport the adjusted slurry to the Nielsen gold concentrator to enrich natural gold particles, perform preliminary separation of gold and copper, and obtain gold rough concentrate and copper concentrate I;

[0037] (4) Grinding and dissociation of some gold and copper conjoined bodies:

[0038] The gold concentrate after the above step (3) is transported to a vertical stirred mill for grinding. The grinding medium is a mixture of ceramic balls and stainless steel balls in a ratio of 4:1. The mill liner is a rubber liner. The mass concentration of the feed to the vertical stirred mill is 50%.

[0039] (5) The slurry after the above step (4) is transported to a hydrocyclone for classification, and the qualified particles with a particle size of -0.043 mm account for 80%. The coarse particles are returned to the ball mill for re-grinding. The feed mass concentration of the hydrocyclone is 50%, the feed pressure is 0.12 MPa, and the overflow mass concentration is 25%;

[0040] (6) Purification of gold concentrate and recovery of some chalcopyrite:

[0041] The slurry with a concentration of 25% after completing the above step (5) is transported to a new high-gradient strong magnetic field magnetic separator system to enrich the chalcopyrite to obtain copper concentrate II, copper concentrate III and gold concentrate. The process is divided into two stages, including a roughing selection and a scavenging selection. The control parameters are: the roughing selection background field strength is 1.2T, the scavenging selection background field strength is 1.4T, the pulse number is 300r / min, the flow rate is 3cm / s, and the load ratio is 0.25;

[0042] (7) The gold concentrate slurry obtained after the above step (6) is transported to a sedimentation tank for sedimentation, and the copper concentrate I obtained after the above step (3) and the copper concentrate II and copper concentrate III obtained after the above step (6) are transported to a dehydration system consisting of a thickener and a filter for dehydration. The gold concentrate (natural gold particles) finally obtained can be directly purified and refined, and the qualified copper concentrate can be used as a raw material for smelting and copper extraction. The small amount of gold contained in the copper concentrate can be recovered.

[0043] Embodiment 1:

[0044] A gold and copper flotation mixed concentrate mainly contains chalcopyrite, as well as a small amount of bornite, pyrite, arsenopyrite, native gold, argero-gold ore, argentite, etc.; the non-metallic minerals contained are mainly quartz and dolomite, followed by calcite and kaolinite. Among them, the vast majority of copper minerals are chalcopyrite, and there is a small amount of bornite. Chalcopyrite mainly exists in the form of monomers, followed by associated with gangue, and occasionally associated with gold and pyrite. Gold exists in the form of free monomer natural gold, accounting for 80.25% of the total gold, and gold dispersed in copper minerals and pyrite in the form of gold associations accounts for 13.50% and 4.20% of the total gold respectively; gold in gangue accounts for 2.05% of the total gold. Its multi-element analysis is shown in Table 1

[0045]

[0046] The present invention is used to implement the gold and copper flotation mixed concentrate, and the specific steps are as follows:

[0047] (1) Destruction of hydrophobic flocs in mixed gold and copper flotation concentrates

[0048] The mineral particles obtained by flotation are hydrophobic. When the particles come into contact, the particles will flocculate due to the hydrophobic force on the surface. This happens between different mineral particles, and it is difficult to separate them from each other. Therefore, this situation must be eliminated during separation. In this case, sodium sulfide is used to desorb the hydrophobic agent adsorbed on the surface of gold and copper minerals, but sodium sulfide can only desorb about 65% of the agent on the surface of the mineral. At the same time, sodium sulfide is a strong alkaline substance. Excessive use and high pH value affect the adsorption and catalytic performance of activated carbon, so it must be strictly controlled when used. Through research on this basis, adding ethanol or butanol can completely desorb the agent adsorbed on the surface of gold and copper particles into the solution. Ethanol or butanol is a heteropolar molecule. It has both lipophilic and hydrophilic properties. Therefore, it has an attraction between hydrophobic organic matter and water molecules. It can dissolve hydrophobic organic matter in aqueous solution and cooperate with sodium sulfide to completely desorb the agent adsorbed on the surface of gold particles and copper minerals, eliminating the flocs generated by different mineral particles. The gold and copper mixed concentrate obtained by flotation and a certain amount of clean water are transported to the 1# stirring barrel, and a mixture of sodium sulfide and ethanol is added for stirring. The slurry mass concentration is 50%, the amount of sodium sulfide is 1.5kg / t, and the amount of ethanol is 1.3kg / t. The gold particles and chalcopyrite flocs are separated and kept dispersed;

[0049] (2) Eliminate organic matter in the solution to keep the aqueous solution clean (without hydrophobic organic matter)

[0050] Organic matter in the solution will affect the recycling of water and cause gold and copper particles to flocculate again, affecting subsequent processing operations, so it must be completely eliminated. Activated carbon is a porous substance with relatively developed internal pores and a large specific surface area. Its surface has a strong adsorption capacity for organic matter. At the same time, it can enrich oxidants in the solution and has the characteristics of catalytic oxidation of surface adsorbed substances, so the solution can be kept clean (without hydrophobic organic matter). The slurry that has completed the above step (1) is transported to the 2# mixing barrel and activated carbon is added for stirring. The amount of activated carbon used is 3.2kg / t, which can quickly adsorb and catalytically oxidize the organic flotation agent in the solution to keep the solution clean;

[0051] (3) Preliminary separation of gold and copper flotation mixed concentrate

[0052] Add clean water to the slurry after completing the above step (2), and then transport the adjusted slurry to the Nelson gold concentrator to enrich the natural gold particles, perform preliminary separation of gold and copper, and obtain gold rough concentrate and copper concentrate I. The control parameters of the Nelson gold concentrator are: -200 mesh content accounts for 65%, feed concentration is 40%, and the expanded gravity multiple is 60 times;

[0053] (4) Grinding and dissociation of some gold and copper conjoined bodies

[0054] The gold concentrate after the above step (3) is transported to the vertical stirred mill for grinding. The grinding medium is a mixture of ceramic balls and stainless steel balls in a certain ratio (4:1). The mill liner is a rubber liner to prevent the surface of the gold particles from being magnetized. The mass concentration of the feed to the vertical stirred mill is 50%.

[0055] (5) The slurry after the above step (4) is transported to the hydrocyclone for classification, and the qualified particles with a particle size of -0.043 mm account for 80% (overflow), and the coarse particles (sand) are returned to the ball mill for re-grinding. The mass concentration of the cyclone feed is 50%, the feed pressure is 0.12MPa, and the overflow mass concentration is 25%.

[0056] (6) Purification of gold concentrate and recovery of some chalcopyrite

[0057] The slurry with a concentration of 25% after completing the above step (5) is transported to a new high-gradient strong magnetic field magnetic separator system to enrich chalcopyrite to obtain copper concentrate II, copper concentrate III and gold concentrate (natural gold particles). The process is divided into two stages, including a roughing selection and a scavenging selection. The control parameters are: the roughing selection background field strength is 1.2T, the scavenging selection background field strength is 1.4T, the pulse number is 300r / min, the flow rate is 3cm / s, and the load ratio is 0.25.

[0058] (7) The gold concentrate (natural gold particles) slurry obtained in step (6) above is transported to a sedimentation tank for sedimentation, and the copper concentrate I obtained in step (3) above and the copper concentrate II and copper concentrate III obtained in step (6) above are transported to a dehydration system consisting of a thickener and a filter for dehydration. The gold concentrate (natural gold particles) finally obtained can be directly purified and refined, and the qualified copper concentrate can be used as a raw material for smelting and copper extraction. The small amount of gold contained in the copper concentrate can be recovered. The final test indicators of this case are: the gold grade of the gold concentrate is 21.77%, and the gold recovery rate is 89.13%; the copper grade of the copper concentrate is 23.97%, and the copper recovery rate is 99.98%.

[0059] Embodiment 2:

[0060] A gold and copper flotation mixed concentrate mainly contains chalcopyrite, as well as a small amount of bornite, pyrite, arsenopyrite, native gold, argero-gold ore, argentite, etc.; the non-metallic minerals contained are mainly quartz and dolomite, followed by calcite and kaolinite. Among them, the vast majority of copper minerals are chalcopyrite, and there is a small amount of bornite. Chalcopyrite mainly exists in the form of monomers, followed by associated with gangue, and occasionally associated with gold and pyrite. Gold exists in the form of free monomer natural gold, accounting for 80.25% of the total gold, and gold dispersed in copper minerals and pyrite in the form of gold associations accounts for 13.50% and 4.20% of the total gold respectively; gold in gangue accounts for 2.05% of the total gold. Its multi-element analysis is shown in Table 1

[0061]

[0062] The present invention is used to implement the gold and copper flotation mixed concentrate, and the specific steps are as follows:

[0063] (1) Destruction of hydrophobic flocs in mixed gold and copper flotation concentrates

[0064] The mineral particles obtained by flotation are hydrophobic. When the particles come into contact, the particles will flocculate due to the hydrophobic force on the surface. This happens between different mineral particles, and it is difficult to separate them from each other. Therefore, this situation must be eliminated during separation. In this case, sodium sulfide is used to desorb the hydrophobic agent adsorbed on the surface of gold and copper minerals, but sodium sulfide can only desorb about 65% of the agent on the surface of the mineral. At the same time, sodium sulfide is a strong alkaline substance. Excessive use and high pH value affect the adsorption and catalytic performance of activated carbon, so it must be strictly controlled when used. Through research on this basis, adding ethanol or butanol can completely desorb the agent adsorbed on the surface of gold and copper particles into the solution. Ethanol or butanol is a heteropolar molecule. It has both lipophilic and hydrophilic properties. Therefore, it has an attraction between hydrophobic organic matter and water molecules. It can dissolve hydrophobic organic matter in aqueous solution and cooperate with sodium sulfide to completely desorb the agent adsorbed on the surface of gold particles and copper minerals, eliminating the flocs generated by different mineral particles. The gold and copper mixed concentrate obtained by flotation and a certain amount of clean water are transported to the 1# stirring barrel, and a mixture of sodium sulfide and ethanol is added for stirring. The slurry mass concentration is 50%, the amount of sodium sulfide is 2.6kg / t, and the amount of ethanol is 2.4kg / t. The gold particles and chalcopyrite flocs are separated and kept dispersed;

[0065] (2) Eliminate organic matter in the solution to keep the aqueous solution clean (without hydrophobic organic matter)

[0066] Organic matter in the solution will affect the recycling of water and cause gold and copper particles to flocculate again, affecting subsequent treatment operations, so it must be completely eliminated. Activated carbon is a porous substance with relatively developed internal pores and a large specific surface area. Its surface has a strong adsorption capacity for organic matter. At the same time, it can enrich oxidants in the solution and has the characteristics of catalytic oxidation of surface adsorbed substances, so the solution can be kept clean (without hydrophobic organic matter). The slurry that has completed the above step (1) is transported to the 2# mixing barrel and activated carbon is added for stirring. The amount of activated carbon used is 3.6kg / t, which can quickly adsorb and catalytically oxidize the organic flotation agent in the solution to keep the solution clean;

[0067] (3) Preliminary separation of gold and copper flotation mixed concentrate

[0068] Add clean water to the slurry after completing the above step (2), and then transport the adjusted slurry to the Nelson gold concentrator to enrich the natural gold particles, perform preliminary separation of gold and copper, and obtain gold rough concentrate and copper concentrate I. The control parameters of the Nelson gold concentrator are: -200 mesh content accounts for 65%, feed concentration is 40%, and the expanded gravity multiple is 60 times;

[0069] (4) Grinding and dissociation of some gold and copper conjoined bodies

[0070] The gold concentrate after the above step (3) is transported to the vertical stirred mill for grinding. The grinding medium is a mixture of ceramic balls and stainless steel balls in a certain ratio (4:1). The mill liner is a rubber liner to prevent the surface of the gold particles from being magnetized. The mass concentration of the feed to the vertical stirred mill is 50%.

[0071] (5) The slurry after the above step (4) is transported to the hydrocyclone for classification, and the qualified particles with a particle size of -0.043 mm account for 80% (overflow), and the coarse particles (sand) are returned to the ball mill for re-grinding. The mass concentration of the cyclone feed is 50%, the feed pressure is 0.12MPa, and the overflow mass concentration is 25%.

[0072] (6) Purification of gold concentrate and recovery of some chalcopyrite

[0073] The slurry with a concentration of 25% after completing the above step (5) is transported to a new high-gradient strong magnetic field magnetic separator system to enrich chalcopyrite to obtain copper concentrate II, copper concentrate III and gold concentrate (natural gold particles). The process is divided into two stages, including a roughing selection and a scavenging selection. The control parameters are: the roughing selection background field strength is 1.2T, the scavenging selection background field strength is 1.4T, the pulse number is 300r / min, the flow rate is 3cm / s, and the load ratio is 0.25.

[0074] (7) The gold concentrate (natural gold particles) slurry obtained in step (6) above is transported to a sedimentation tank for sedimentation, and the copper concentrate I obtained in step (3) above and the copper concentrate II and copper concentrate III obtained in step (6) above are transported to a dehydration system consisting of a thickener and a filter for dehydration. The gold concentrate (natural gold particles) finally obtained can be directly purified and refined, and the qualified copper concentrate can be used as a raw material for smelting and copper extraction. The small amount of gold contained in the copper concentrate can be recovered. The final test indicators of this case are: the gold grade of the gold concentrate is 21.03%, and the gold recovery rate is 91.42%; the copper grade of the copper concentrate is 24.71%, and the copper recovery rate is 99.98%.

[0075] Embodiment 3:

[0076] A gold and copper flotation mixed concentrate mainly contains chalcopyrite, as well as a small amount of bornite, pyrite, arsenopyrite, native gold, argero-gold ore, argentite, etc.; the non-metallic minerals contained are mainly quartz and dolomite, followed by calcite and kaolinite. Among them, the vast majority of copper minerals are chalcopyrite, and there is a small amount of bornite. Chalcopyrite mainly exists in the form of monomers, followed by associated with gangue, and occasionally associated with gold and pyrite. Gold exists in the form of free monomer natural gold, accounting for 80.25% of the total gold, and gold dispersed in copper minerals and pyrite in the form of gold associations accounts for 13.50% and 4.20% of the total gold respectively; gold in gangue accounts for 2.05% of the total gold. Its multi-element analysis is shown in Table 1

[0077]

[0078] The present invention is used to implement the gold and copper flotation mixed concentrate, and the specific steps are as follows:

[0079] (1) Destruction of hydrophobic flocs in mixed gold and copper flotation concentrates

[0080] The mineral particles obtained by flotation are hydrophobic. When the particles come into contact, the particles will flocculate due to the hydrophobic force on the surface. This happens between different mineral particles, and it is difficult to separate them from each other. Therefore, this situation must be eliminated during separation. In this case, sodium sulfide is used to desorb the hydrophobic agent adsorbed on the surface of gold and copper minerals, but sodium sulfide can only desorb about 65% of the agent on the surface of the mineral. At the same time, sodium sulfide is a strong alkaline substance. Excessive use and high pH value affect the adsorption and catalytic performance of activated carbon, so it must be strictly controlled when used. Through research on this basis, adding ethanol or butanol can completely desorb the agent adsorbed on the surface of gold and copper particles into the solution. Ethanol or butanol is a heteropolar molecule. It has both lipophilic and hydrophilic properties. Therefore, it has an attraction between hydrophobic organic matter and water molecules. It can dissolve hydrophobic organic matter in aqueous solution and cooperate with sodium sulfide to completely desorb the agent adsorbed on the surface of gold particles and copper minerals, eliminating the flocs generated by different mineral particles. The gold and copper mixed concentrate obtained by flotation and a certain amount of clean water are transported to the 1# stirring barrel, and a mixture of sodium sulfide and ethanol is added for stirring. The slurry mass concentration is 50%, the amount of sodium sulfide is 2.0kg / t, and the amount of ethanol is 2.0kg / t. The gold particles and chalcopyrite flocs are separated and kept dispersed;

[0081] (2) Eliminate organic matter in the solution to keep the aqueous solution clean (without hydrophobic organic matter)

[0082] Organic matter in the solution will affect the recycling of water and cause gold and copper particles to flocculate again, affecting subsequent treatment operations, so it must be completely eliminated. Activated carbon is a porous substance with relatively developed internal pores and a large specific surface area. Its surface has a strong adsorption capacity for organic matter. At the same time, it can enrich oxidants in the solution and has the characteristics of catalytic oxidation of surface adsorbed substances, so the solution can be kept clean (without hydrophobic organic matter). The slurry that has completed the above step (1) is transported to the 2# mixing barrel and activated carbon is added for stirring. The amount of activated carbon used is 3.5kg / t, which can quickly adsorb and catalytically oxidize the organic flotation agent in the solution to keep the solution clean;

[0083] (3) Preliminary separation of gold and copper flotation mixed concentrate

[0084] Add clean water to the slurry after completing the above step (2), and then transport the adjusted slurry to the Nelson gold concentrator to enrich the natural gold particles, perform preliminary separation of gold and copper, and obtain gold rough concentrate and copper concentrate I. The control parameters of the Nelson gold concentrator are: -200 mesh content accounts for 65%, feed concentration is 40%, and the expanded gravity multiple is 60 times;

[0085] (4) Grinding and dissociation of some gold and copper conjoined bodies

[0086] The gold concentrate after the above step (3) is transported to the vertical stirred mill for grinding. The grinding medium is a mixture of ceramic balls and stainless steel balls in a certain ratio (4:1). The mill liner is a rubber liner to prevent the surface of the gold particles from being magnetized. The mass concentration of the feed to the vertical stirred mill is 50%.

[0087] (5) The slurry after the above step (4) is transported to the hydrocyclone for classification, and the qualified particles with a particle size of -0.043 mm account for 80% (overflow), and the coarse particles (sand) are returned to the ball mill for re-grinding. The mass concentration of the cyclone feed is 50%, the feed pressure is 0.12MPa, and the overflow mass concentration is 25%.

[0088] (6) Purification of gold concentrate and recovery of some chalcopyrite

[0089] The slurry with a concentration of 25% after completing the above step (5) is transported to a new high-gradient strong magnetic field magnetic separator system to enrich chalcopyrite to obtain copper concentrate II, copper concentrate III and gold concentrate (natural gold particles). The process is divided into two stages, including a roughing selection and a scavenging selection. The control parameters are: the roughing selection background field strength is 1.2T, the scavenging selection background field strength is 1.4T, the pulse number is 300r / min, the flow rate is 3cm / s, and the load ratio is 0.25.

[0090] (7) The gold concentrate (natural gold particles) slurry obtained in step (6) above is transported to a sedimentation tank for sedimentation, and the copper concentrate I obtained in step (3) above and the copper concentrate II and copper concentrate III obtained in step (6) above are transported to a dehydration system consisting of a thickener and a filter for dehydration. The gold concentrate (natural gold particles) finally obtained can be directly purified and refined, and the qualified copper concentrate can be used as a raw material for smelting and copper extraction. The small amount of gold contained in the copper concentrate can be recovered. The final test indicators of this case are: the gold grade of the gold concentrate is 20.45%, and the gold recovery rate is 90.26%; the copper grade of the copper concentrate is 24.36%, and the copper recovery rate is 99.99%.

[0091] The above cases fully illustrate that: by adopting the invention, the gold and copper indicators obtained are stable and reliable, and the invention has good adaptability to different flotation gold and copper flotation mixed concentrates.

Claims

1. A method for separating mixed concentrates of gold and copper by flotation, characterized in that: The following steps are involved: (1) Destruction of hydrophobic flocs in mixed gold and copper flotation concentrates: The gold and copper mixed concentrate obtained by flotation and a certain amount of clean water are transported to the 1# stirring barrel, and a mixture of sodium sulfide and ethanol is added for stirring. The slurry mass concentration is 50%, the amount of sodium sulfide is 1.5~2.6kg / t, and the amount of ethanol is 1.3~2.4kg / t. The gold particles and chalcopyrite flocs are separated and kept dispersed; (2) Eliminate organic matter in the solution to keep the aqueous solution clean: The slurry after the above step (1) is transported to the 2# mixing tank, and activated carbon is added and stirred for 15 minutes; the amount of activated carbon used is 3.2~3.6kg / t; (3) Preliminary pre-separation of gold and copper flotation mixed concentrate: Add clean water to the slurry after completing the above step (2), and transport the adjusted slurry to the Nielsen gold concentrator to enrich natural gold particles, perform preliminary separation of gold and copper, and obtain gold rough concentrate and copper concentrate I; (4) Grinding and dissociation of some gold and copper conjoined bodies: The gold concentrate after the above step (3) is transported to a vertical stirred mill for grinding. The grinding medium is a mixture of ceramic balls and stainless steel balls in a ratio of 4:

1. The mill liner is a rubber liner. The mass concentration of the feed to the vertical stirred mill is 50%. (5) The slurry after the above step (4) is transported to a hydrocyclone for classification, and the qualified particles with a particle size of -0.043 mm account for 80%. The coarse particles are returned to the ball mill for re-grinding. The feed mass concentration of the hydrocyclone is 50%, the feed pressure is 0.12 MPa, and the overflow mass concentration is 25%; (6) Purification of gold concentrate and recovery of some chalcopyrite: The slurry with a concentration of 25% after completing the above step (5) is transported to a new high-gradient strong magnetic field magnetic separator system to enrich the chalcopyrite to obtain copper concentrate II, copper concentrate III and gold concentrate. The process is divided into two stages, including a roughing selection and a scavenging selection. The control parameters are: the roughing selection background field strength is 1.2T, the scavenging selection background field strength is 1.4T, the pulse number is 300r / min, the flow rate is 3cm / s, and the load ratio is 0.25; (7) The gold concentrate slurry obtained after the above step (6) is transported to a sedimentation tank for sedimentation, and the copper concentrate I obtained after the above step (3) and the copper concentrate II and copper concentrate III obtained after the above step (6) are transported to a dehydration system consisting of a thickener and a filter for dehydration. The gold concentrate (natural gold particles) finally obtained can be directly purified and refined, and the qualified copper concentrate can be used as a raw material for smelting and copper extraction. The small amount of gold contained in the copper concentrate can be recovered.

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