Beneficiation method for recovering precious metal in copper-nickel ore through combination of multiple gravity fields

Abstract

The invention discloses a beneficiation method for recovering precious metal in copper-nickel ore through combination of multiple gravity fields. According to the beneficiation method, centrifugal reselection, flotation, sedimentation reselection and dense medium beneficiation technologies are combined. The technology belongs to the technical field of non-ferrous metal mineral separation, and mainly comprises the following steps that S1, after raw ore is subjected to crushing, ore grinding and grading pretreatment, a sand setting product is subjected to size mixing, then Nelson centrifugal gravity separation is conducted, Nelson gravity separation concentrate K1 and gravity separation tailings are obtained, the gravity separation tailings are returned to the ore grinding and grading process, and grading overflow products are subjected to copper-nickel flotation; s2, after size mixing is conducted on copper-nickel bulk concentrate obtained through copper-nickel bulk flotation, felt sedimentation gravity separation is conducted, and copper-nickel concentrate and felt gravity separation precious metal concentrate K2 are obtained; and S3, the felt gravity concentration concentrate K2 is prepared into dense medium suspension liquid, the Nelson gravity concentration concentrate K1 serves as a raw material and is fed into a dense medium cyclone for dense medium separation, dense medium separation concentrate and dense medium separation tailings are obtained, and the dense medium separation concentrate is the final precious metal product. The self-produced gravity separation product is used as a dense medium to further enrich the centrifugal gravity separation product, a novel precious metal enrichment technology is developed, the quality and grade of the precious metal separation product in the copper-nickel ore are improved, the comprehensive utilization rate of the precious metal in the copper-nickel ore is greatly increased, and the method is suitable for industrial production. And meanwhile, the difficult problem of medium separation and recovery in dense medium mineral separation is effectively solved, and the cost is remarkably reduced.

Description

Technical Field

[0001] The invention relates to the technical field of nonferrous metal mineral beneficiation, and in particular to a beneficiation method for recovering precious metals in copper-nickel ores by utilizing multiple force fields. Background Art

[0002] Copper-nickel sulfide ores are usually associated with a certain amount of precious metals, such as gold and platinum. Traditional single beneficiation methods often have problems such as low efficiency, large fluctuations in concentrate grade, high cost, and complex processes when recovering these precious metals. Especially when facing low-grade difficult-to-process ores, the single use of Nelson centrifugal gravity separation is not enough to meet the requirements for precious metal recovery. In order to improve the recovery effect of precious metals and reduce costs, it is particularly important to develop an efficient beneficiation process. The heavy liquid or heavy suspension used in conventional heavy medium separation is expensive and difficult to recover, and has poor environmental protection and economic performance.

[0003] China's invention patent "A beneficiation method for enriching platinum group metals in complex sulfide copper-nickel ore", patent number CN116037308A discloses a beneficiation method for recovering precious metals from flotation concentrate using a Nelson concentrator. The method relies solely on the Nelson centrifugal field to enrich precious metals. When processing low-grade ores, the product grade obtained is low, and the flotation concentrate has high foam fineness and high viscosity. The Nelson applicability is poor and the product enrichment ratio is low. Summary of the invention

[0004] The purpose of the present invention is to provide a multi-force field combined beneficiation method for recovering precious metals from copper-nickel ores, and to recover precious metals such as gold and platinum from copper-nickel sulfide ores. The method combines centrifugal gravity separation, flotation, sedimentation gravity separation and heavy medium beneficiation technology, which can effectively improve the recovery rate and grade of precious metals and reduce the cost of beneficiation.

[0005] In order to achieve the above technical purpose, the present invention provides a method for recovering precious metals from copper-nickel ores by combining multiple force fields, and the specific steps are as follows: (1) Pretreatment: The copper-nickel sulfide ore is crushed, ground and classified to obtain a sand settling product and a classified overflow product.

[0006] The crushing particle size of copper-nickel sulfide ore is ≤12mm, and the particle size of grinding product is less than 6mm; the content of -0.074mm in the classified overflow product is greater than 60%.

[0007] (2) Nelson centrifugal gravity separation: The grit product is slurried and sent to the Nelson centrifugal gravity separation equipment to obtain Nelson gravity separation concentrate K1 and gravity separation tailings. The gravity separation tailings are returned to the grinding and classification process for further grinding and classification. The classification overflow product is sent to the copper-nickel mixed flotation process.

[0008] The Nelson centrifugal gravity separation feed particle size is 1-6 mm, the feed concentration is 20%-75%, and the centrifugal acceleration is 60G-100G.

[0009] (3) Copper-nickel flotation: After the overflow slurry from the classification in step (1) is slurried, a regulator, a collector and a frother are added in sequence, and at least one roughing, two cleaning and two scavenging are performed to obtain a copper-nickel mixed concentrate and flotation tailings.

[0010] The slurry concentration of the classified overflow product is 25%-35%.

[0011] The regulator includes one or more of sodium carboxymethyl cellulose, copper sulfate, ammonium sulfate, sodium hexametaphosphate, and water glass; the collector includes one or more of ethyl xanthate, butyl xanthate, butyl ammonium black medicine, and isoleucine; the foaming agent includes one or more of pineneol, ammonium black medicine, and methyl amyl alcohol.

[0012] (4) Mixed concentrate sedimentation and gravity separation: The copper-nickel mixed concentrate obtained by copper-nickel flotation is slurried and then sent to the felt concentrator of sedimentation and gravity separation equipment. After felt sedimentation and gravity separation, copper-nickel concentrate and felt gravity separation precious metal concentrate K2 are obtained.

[0013] The felt re-selection equipment is a felt concentrator or a felt chute, and the felt is a fiber gold panning cloth or a polyethylene gold panning cloth, and the height of the gold panning cloth is greater than 10 mm.

[0014] (5) Heavy medium separation: The felt gravity separation concentrate is prepared into a heavy medium suspension. The Nelson gravity separation concentrate K1 is fed into the heavy medium cyclone as a raw material for separation. After separation, heavy medium separation concentrate and heavy medium separation tailings are obtained. The heavy medium separation concentrate is the final precious metal product. The heavy medium separation tailings are returned to the grinding and classification flotation process to continue the copper and nickel flotation.

[0015] The configuration density of the heavy medium suspension is 2.0-2.5g / cm³, the particle size range is -0.074 mm and the content is 60% to 80%. The heavy medium separation process uses a heavy medium cyclone, and the diameter of the heavy medium cyclone is 100-200mm.

[0016] Compared with the prior art, the beneficial effects of the present invention include: 1. Improve product quality: The present invention can significantly improve the quality and grade of precious metal products and meet higher standards of market demand.

[0017] 2. Improve the recovery rate of precious metals: By combining centrifugal gravity separation, sedimentation gravity separation and heavy medium separation technology, the comprehensive utilization rate of precious metals in copper-nickel ores is effectively improved.

[0018] 3. Reduce the cost of mineral processing: Using self-produced heavy separation products as heavy media has strong operability in the heavy medium sorting process, and the entry of precious metal products will not have a negative impact on the quality. At the same time, it solves the problem that traditional heavy media is difficult to separate and recover, effectively reducing the cost of mineral processing.

[0019] 4. Environmental protection and energy saving: The whole process is reasonably designed, which reduces the waste of resources and has good environmental protection and energy saving effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a process flow chart for precious metal recovery combining multi-stage gravity separation and heavy medium separation. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] Example 1: For a certain sulfide copper-nickel ore, the raw ore contains 0.3g / t gold, 4.3g / t silver, 0.3g / t platinum and a small amount of other precious metals, and the main gangue is light magnesium silicate minerals. It is processed according to the following process: 1. Pretreatment: The original ore has a particle size of 0-100mm. It is crushed and ground by a cone crusher and a ball mill, and classified by a hydrocyclone to obtain a sand settling product and a classified overflow product. The classified overflow product has a -0.074mm content of 70%; 2. Nelson centrifugal gravity separation: The classified grit products are sent to the Nelson centrifugal gravity separation equipment. The Nelson centrifugal gravity separation feed size is 2-3mm, the Nelson feed concentration is 45%, and the centrifugal acceleration is 90G to obtain the Nelson gravity separation concentrate K1 and gravity separation tailings. The gravity separation tailings are returned to the grinding and classification process for further grinding and classification. The classified overflow products are sent to the copper-nickel mixed flotation process.

[0023] 3. Copper-nickel flotation: The classified overflow pulp in step 1 is slurried with a slurry concentration of 30%. After treatment, 20 g / t of copper sulfate, 600 g / t of ammonium sulfate, 300 g / t of ethyl xanthate, 20 g / t of isoleucine, and 10 g / t of pine alcohol are added in sequence. One roughing, two cleanings, and two scavengings are performed to obtain a copper-nickel mixed concentrate and flotation tailings.

[0024] 4. Mixed concentrate sedimentation gravity separation: The copper-nickel mixed concentrate obtained by copper-nickel flotation is slurried and then sent to the felt concentrator of sedimentation gravity separation equipment, using fiber gold panning cloth with a height of 15mm, and enriched for 48 hours. After felt sedimentation gravity separation, copper-nickel concentrate and felt gravity separation precious metal concentrate K2 are obtained.

[0025] 5. Heavy medium separation: The felt gravity separation concentrate is prepared into a heavy medium suspension with a density of 2.5g / cm³. The Nelson gravity separation concentrate is fed into a Φ100 heavy medium cyclone as a raw material for separation. After separation, heavy medium separation concentrate and heavy medium separation tailings are obtained. The heavy medium separation tailings are returned to the grinding and classification process to continue copper and nickel flotation. The heavy medium separation concentrate is the final precious metal product, with a gold grade of 95g / t, a platinum grade of 280g / t, and a silver grade of 194g / t.

[0026] It can be seen from the above embodiments that the mineral processing technology of the present invention can effectively improve the grade of precious metals in copper-nickel ore with ideal effect, while reducing the mineral processing cost, and has high application value.

[0027] Example 2: For a certain sulfide copper-nickel ore, the raw ore contains 0.06g / t of gold, 0.03g / t of platinum and a small amount of other precious metals, and the main gangue is light magnesium silicate minerals. It is processed according to the following process: 1. Pretreatment: The original ore has a particle size of 0-100mm. It is crushed and ground by a cone crusher and a ball mill, and classified by a hydrocyclone to obtain a sand settling product and a classified overflow product. The content of the classified overflow product -0.074mm is 65%; 2. Nelson centrifugal gravity separation: The classified grit products are sent to the Nelson centrifugal gravity separation equipment. The Nelson centrifugal gravity separation feed size is 2-3mm, the Nelson feed concentration is 45%, and the centrifugal acceleration is 90G to obtain the Nelson gravity separation concentrate K1 and gravity separation tailings. The gravity separation tailings are returned to the grinding and classification process for further grinding and classification. The classified overflow products are sent to the copper-nickel mixed flotation process.

[0028] 3. Copper-nickel flotation: The classified overflow pulp in step 1 is slurried with a slurry concentration of 30%. After treatment, 200 g / t of ammonium sulfate, 300 g / t of ethyl xanthate, 20 g / t of isoleucine, and 10 g / t of pine alcohol are added in sequence. One roughing, two cleanings, and two scavengings are performed to obtain a copper-nickel mixed concentrate and flotation tailings.

[0029] 4. Mixed concentrate sedimentation gravity separation: The copper-nickel mixed concentrate obtained by copper-nickel flotation is slurried and then sent to the felt concentrator of sedimentation gravity separation equipment, using fiber gold panning cloth with a height of 15mm, and enriched for 48 hours. After felt sedimentation gravity separation, copper-nickel concentrate and felt gravity separation precious metal concentrate K2 are obtained.

[0030] 5. Heavy medium separation: The felt gravity separation concentrate is prepared into a heavy medium suspension with a density of 2.0g / cm³. The Nelson gravity separation concentrate is fed into a Φ100 heavy medium cyclone as a raw material for separation. After separation, heavy medium separation concentrate and heavy medium separation tailings are obtained. The heavy medium separation tailings are returned to the grinding and classification process to continue copper and nickel flotation. The heavy medium separation concentrate is the final precious metal product, with a gold grade of 34g / t and a platinum grade of 150g / t.

[0031] It can be seen from the above embodiments that the mineral processing technology of the present invention can also effectively improve the grade of precious metals in low-grade copper-nickel ores, with a relatively ideal effect, while reducing the mineral processing cost, and has a high application value.

Claims

1. A method for recovering precious metals from copper-nickel ores by combining multiple force fields, characterized in that: The following steps are involved: (1) Pretreatment: crushing, grinding and grading the sulfide copper-nickel ore to obtain a sand settling product and a graded overflow product; (2) Nelson centrifugal gravity separation: The grit product is slurried and sent to the Nelson centrifugal gravity separation equipment to obtain Nelson gravity separation concentrate K1 and gravity separation tailings; The Nelson gravity separation tailings are returned to the grinding and classification process to continue the grinding and classification process in step (1); the Nelson gravity separation concentrate K1 is used as a raw material for step (5); and the classification overflow product is sent to step (3) for copper-nickel flotation process; (3) Copper-nickel flotation: after slurry treatment of the overflow product from the classification in step (1), a regulator, a collector and a frother are added in sequence, and at least one roughing, one cleaning and one scavenging are performed to obtain a mixed concentrate and flotation tailings; (4) Mixed concentrate sedimentation and gravity separation: The mixed concentrate obtained by copper-nickel mixed flotation is slurried and then sent to the felt sedimentation and gravity separation equipment to obtain copper-nickel concentrate and felt gravity separation precious metal concentrate K2; (5) Heavy medium separation: The felt gravity separation concentrate is prepared into a heavy medium suspension, and the Nelson gravity separation concentrate K1 is fed into a heavy medium cyclone as a raw material for separation to obtain a heavy medium separation concentrate and a heavy medium separation tailings. The heavy medium separation concentrate is the final precious metal concentrate, and the heavy medium separation tailings are returned to the grinding and classification process to continue steps (1) to (5).

2. The method for recovering precious metals from copper-nickel ores by using multiple force fields according to claim 1, characterized in that: In step (1), the crushing particle size of the copper-nickel sulfide ore is ≤12 mm, the particle size of the grinding product is less than 6 mm, and the content of -0.074 mm in the classified overflow product is greater than 60%.

3. The method for recovering precious metals from copper-nickel ores by using multiple force fields according to claim 1, characterized in that: In step (2), the Nelson centrifugal gravity separation feed particle size is 1-6 mm, the feed concentration is 20%-75%, and the centrifugal acceleration is 60G-100G.

4. The method for recovering precious metals from copper-nickel ores by combining multiple force fields according to claim 1, characterized in that: In step (3), the slurry concentration of the classified overflow product is 25%-35%.

5. The method for recovering precious metals from copper-nickel ores by combining multiple force fields according to claim 1, characterized in that: In step (3), the adjusting agent includes one or more of sodium carboxymethyl cellulose, copper sulfate, ammonium sulfate, sodium hexametaphosphate, and water glass; the collecting agent includes one or more of ethyl xanthate, butyl xanthate, butyl ammonium black medicine, and isoleucine; and the foaming agent includes one or more of pineneol, ammonium black medicine, and methyl amyl alcohol.

6. The method for recovering precious metals from copper-nickel ores by using multiple force fields according to claim 1, characterized in that: In step (4), the felt re-selection equipment is a felt concentrator or a felt chute, and the felt is a fiber gold panning cloth or a polyethylene gold panning cloth, and the height of the gold panning cloth is greater than 10 mm.

7. The method for recovering precious metals from copper-nickel ores by combining multiple force fields according to claim 1, characterized in that: In step (5), the configuration density of the heavy medium suspension is 2.0-2.5 g / cm³, the particle size range is -0.074 mm, and the content is 60% to 80%.

8. The method for recovering precious metals from copper-nickel ores by using multiple force fields according to claim 1, characterized in that: In step (5), the heavy medium separation process uses a heavy medium cyclone, and the diameter of the heavy medium cyclone is 100-200 mm.

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