A beneficiation method for recovering precious metals in copper-nickel ore in multiple gravity fields

Abstract

The application discloses a beneficiation method for recovering precious metals in copper-nickel ore in multiple gravity fields, which combines centrifugal gravity separation, flotation, sedimentation gravity separation and heavy medium beneficiation technology. The process belongs to the technical field of non-ferrous metal ore beneficiation, and mainly comprises the following steps: S1, after the original ore is crushed, ground, and pretreated by grading, the sand setting product is thickened and then subjected to Nelson centrifugal gravity separation to obtain Nelson gravity separation concentrate K1 and gravity separation tailings; the gravity separation tailings are returned to the grinding and grading process, and the overflow product is subjected to copper-nickel flotation; S2, the copper-nickel mixed concentrate obtained through copper-nickel mixed flotation is thickened and then subjected to felt sedimentation gravity separation to obtain copper-nickel concentrate and felt gravity separation precious metal concentrate K2; and S3, the felt gravity separation concentrate K2 is prepared into a heavy medium suspension, and the Nelson gravity separation concentrate K1 is used as raw material and fed into a heavy medium cyclone for heavy medium separation to obtain heavy medium separation concentrate and heavy medium separation tailings, and the heavy medium separation concentrate is the final precious metal product. The application further enriches the centrifugal gravity separation product by using the self-produced gravity separation product as the heavy medium, develops a new type of precious metal enrichment technology, improves the quality and grade of the precious metal beneficiation product in the copper-nickel ore, greatly improves the comprehensive utilization rate of the precious metal in the copper-nickel ore, effectively solves the problem of medium separation and recovery in the heavy medium beneficiation, and remarkably reduces the cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-ferrous mineral processing, in particular to a beneficiation method for recovering precious metals in copper-nickel ore by using multiple gravity fields. BACKGROUND

[0002] Copper-nickel sulfide ore usually contains a certain amount of precious metals such as gold and platinum. Traditional single beneficiation methods often have low efficiency, large fluctuations in concentrate grade, high cost, and complex process when recovering these precious metals, especially when dealing with low-grade and difficult-to-process ores. Single use of the Nelson centrifugal gravity separation is not enough to meet the requirements of precious metal recovery. In order to improve the recovery effect of precious metals and reduce the cost, 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 economy.

[0003] Chinese invention patent "Beneficiation method for enriching platinum group metals in complex copper-nickel sulfide 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 force field to enrich precious metals. When dealing with low-grade ores, the product grade is low, and the flotation concentrate foam has high fineness and high viscosity. The Nelson has poor applicability, and the product has low enrichment ratio. SUMMARY

[0004] The purpose of the present application is to provide a beneficiation method for recovering precious metals in copper-nickel ore by using multiple gravity fields. The method can effectively improve the recovery rate and grade of precious metals and reduce the beneficiation cost by combining centrifugal gravity separation, flotation, settling gravity separation, and heavy medium separation technology.

[0005] To achieve the above technical purpose, the present application provides a beneficiation method for recovering precious metals in copper-nickel ore by using multiple gravity fields, and the specific steps are as follows:

[0006] (1) Pretreatment: The copper-nickel sulfide ore is pretreated by crushing, grinding, and classification to obtain a sand product and a classification overflow product.

[0007] The crushed particle size of the copper-nickel sulfide ore is ≤12mm, and the ground product particle size is less than 6mm; the classification overflow product has a -0.074mm content of more than 60%.

[0008] (2) Nelson centrifugal gravity separation: The sand product is sent to the Nelson centrifugal gravity separation equipment after being conditioned, to obtain a Nelson gravity separation concentrate K1 and a 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.

[0009] The Nelson centrifugal reselection gives the ore particle size of 1-6 mm, the ore concentration of 20%-75%, and the centrifugal acceleration of 60G-100G.

[0010] (3) Copper-nickel flotation: After the step (1) grading overflow slurry is treated by slurry conditioning, adjusting agent, collector and frother are added in turn, at least one roughing, two cleaning and two scavenging are carried out to obtain copper-nickel mixed concentrate and flotation tailings.

[0011] The slurry conditioning concentration of the grading overflow product is 25%-35%.

[0012] The adjusting agent 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 frother includes one or more of terpene alcohol, ammonium black medicine and methyl amyl alcohol.

[0013] (4) Mixed concentrate sedimentation reselection: the copper-nickel mixed concentrate obtained by copper-nickel flotation is treated by slurry conditioning, and then sent to the felt ore dressing machine of the sedimentation reselection equipment. After the felt sedimentation reselection, copper-nickel concentrate and felt reselection precious metal concentrate K2 are obtained.

[0014] The felt reselection equipment is a felt ore dressing machine 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.

[0015] (5) Heavy medium separation: the felt reselection concentrate is prepared into a heavy medium suspension. The Nelson reselection concentrate K1 is used as raw material to feed into the heavy medium cyclone 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 return to the grinding and classification flotation process to continue copper-nickel flotation.

[0016] The configuration density of the heavy medium suspension is 2.0-2.5 g / cm³, and the particle size range is 60%-80% of-0.074 mm content. The heavy medium separation process uses a heavy medium cyclone, and the diameter of the heavy medium cyclone is 100-200 mm.

[0017] Compared with the prior art, the beneficial effects of the present application include:

[0018] 1. Improve product quality: the present application can significantly improve the quality and grade of precious metal products, and meet the market demand of higher standards.

[0019] 2. Improve the recovery rate of precious metals: by combining centrifugal reselection, sedimentation reselection and heavy medium separation technology, the comprehensive utilization rate of precious metals in copper-nickel ore is effectively improved.

[0020] 3. Reduce mineral processing costs: Using self-produced gravity separation products as heavy media makes the process highly operable and ensures that the products entering the precious metals market will not have a negative impact on their quality. At the same time, it solves the problem of traditional heavy media being difficult to separate and recover, effectively reducing mineral processing costs.

[0021] 4. Environmental protection and energy saving: The entire process flow is reasonably designed, which reduces resource waste and has good environmental protection and energy saving effects. Attached Figure Description

[0022] Figure 1 This is a flow chart of a precious metal recovery process that combines multi-stage gravity separation and heavy media separation. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. The specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0024] Example 1: For a certain copper-nickel sulfide ore, the raw ore contains 0.3 g / t of gold, 4.3 g / t of silver, 0.3 g / t of platinum, and trace amounts of other precious metals. The main gangue is light magnesium silicate minerals. It is processed according to the following method:

[0025] 1. Pretreatment: The raw ore has a particle size of 0-100mm. It is crushed and ground by a cone crusher and a ball mill, and then classified by a hydrocyclone to obtain underflow product and classification overflow product. The classification overflow product has a -0.074mm content of 70%.

[0026] 2. Nelson Centrifugal Gravity Separation: The graded sediment is fed into a Nelson centrifugal gravity separator. The feed particle size is 2-3 mm, the feed concentration is 45%, and the centrifugal acceleration is 90G, yielding Nelson gravity concentrate K1 and gravity tailings. The gravity tailings are returned to the grinding and classification process for further grinding and classification. The overflow product from the classification process is sent to the copper-nickel mixed flotation stage.

[0027] 3. Copper-nickel flotation: The overflow slurry from step 1 is conditioned to a 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 terpineol are added sequentially. One roughing, two cleaning, and two scavenging processes are performed to obtain a copper-nickel mixed concentrate and flotation tailings.

[0028] 4. Mixed Concentrate Sedimentation and Gravity Separation: The copper-nickel mixed concentrate obtained from copper-nickel flotation is slurry-treated and then fed into a felt separator for sedimentation and gravity separation using fiber gold panning cloth with a cloth height of 15mm for 48 hours. After felt sedimentation and gravity separation, copper-nickel concentrate and felt gravity separation precious metal concentrate K2 are obtained.

[0029] 5. Heavy Media Separation: The felt gravity concentrate is prepared into a heavy media suspension with a density of 2.5 g / cm³. The Nelson gravity concentrate is fed into a Φ100 heavy media hydrocyclone for separation. After separation, heavy media concentrate and heavy media tailings are obtained. The heavy media tailings are returned to the grinding and classification process for further copper-nickel flotation. The heavy media concentrate is the final precious metal product, with a gold grade of 95 g / t, a platinum grade of 280 g / t, and a silver grade of 194 g / t.

[0030] As can be seen from the above embodiments, the mineral processing technology of the present invention can effectively improve the grade of precious metals in copper-nickel ore, with ideal results, while reducing mineral processing costs, and has high application value.

[0031] Example 2: For a certain copper-nickel sulfide ore, the raw ore contains 0.06 g / t of gold, 0.03 g / t of platinum, and trace amounts of other precious metals. The main gangue is light magnesium silicate minerals. It is processed according to the following method:

[0032] 1. Pretreatment: The raw ore has a particle size of 0-100mm. It is crushed and ground by a cone crusher and a ball mill, and then classified by a hydrocyclone to obtain underflow product and classification overflow product. The classification overflow product has a -0.074mm content of 65%.

[0033] 2. Nelson Centrifugal Gravity Separation: The graded sediment is fed into a Nelson centrifugal gravity separator. The feed particle size is 2-3 mm, the feed concentration is 45%, and the centrifugal acceleration is 90G, yielding Nelson gravity concentrate K1 and gravity tailings. The gravity tailings are returned to the grinding and classification process for further grinding and classification. The overflow product from the classification process is sent to the copper-nickel mixed flotation stage.

[0034] 3. Copper-nickel flotation: The overflow slurry from step 1 is conditioned to a 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 terpineol are added sequentially. One roughing, two cleaning, and two scavenging processes are performed to obtain a copper-nickel mixed concentrate and flotation tailings.

[0035] 4. Mixed Concentrate Sedimentation and Gravity Separation: The copper-nickel mixed concentrate obtained from copper-nickel flotation is slurry-treated and then fed into a felt separator for sedimentation and gravity separation using fiber gold panning cloth with a cloth height of 15mm for 48 hours. After felt sedimentation and gravity separation, copper-nickel concentrate and felt gravity separation precious metal concentrate K2 are obtained.

[0036] 5. Heavy Media Separation: The felt gravity concentrate is prepared into a heavy media suspension with a density of 2.0 g / cm³. The Nelson gravity concentrate is fed into a Φ100 heavy media hydrocyclone for separation. After separation, heavy media concentrate and heavy media tailings are obtained. The heavy media tailings are returned to the grinding and classification process for further copper-nickel flotation. The heavy media concentrate is the final precious metal product, with a gold grade of 34 g / t and a platinum grade of 150 g / t.

[0037] As can be seen from the above embodiments, the mineral processing technology of the present invention can also effectively improve the grade of precious metals in low-grade copper-nickel ore, with ideal results, while reducing mineral processing costs and having high application value.

Claims

1. A mineral processing method for recovering precious metals from copper-nickel ore using a multi-force field combined approach, characterized in that, Includes the following steps: (1) Pretreatment: The copper-nickel sulfide ore is crushed, ground and classified to obtain the sand product and the graded overflow product. (2) Nelson centrifugal gravity separation: The sand product is fed into the Nelson centrifugal gravity separation equipment after slurry conditioning to obtain Nelson gravity concentrate K1 and gravity 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 raw material for step (5); the classification overflow product is sent to step (3) for copper-nickel flotation. (3) Copper-nickel flotation: After the graded overflow product in step (1) is slurry-treated, a modifier, a collector and a frother are added in sequence, and at least one roughing, one cleaning and one scavenging are carried out to obtain mixed concentrate and flotation tailings; (4) Mixed concentrate sedimentation and gravity separation: The mixed concentrate obtained by copper-nickel mixed flotation is slurry-treated 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 media separation: The felt gravity concentrate is prepared into a heavy media suspension, and the Nelson gravity concentrate K1 is fed into the heavy media hydrocyclone for separation to obtain heavy media separation concentrate and heavy media separation tailings. The heavy media separation concentrate is the final precious metal concentrate, and the heavy media separation tailings are returned to the grinding and classification process to continue steps (1)-(5).

2. The beneficiation method for recovering precious metals from copper-nickel ore using a multi-force field combined method according to claim 1, characterized in that, In step (1), the crushed particle size of copper-nickel sulfide ore is ≤12mm, the particle size of the grinding product is less than 6mm, and the content of -0.074mm in the graded overflow product is greater than 60%.

3. The beneficiation method for recovering precious metals from copper-nickel ore using a multi-force field combined method according to claim 1, characterized in that, In step (2), the particle size of the feed for the Nelson centrifugal gravity separation is 1~6mm, the feed concentration is 20%~75%, and the centrifugal acceleration is 60G~100G.

4. The beneficiation method for recovering precious metals from copper-nickel ore using a multi-force field combined method according to claim 1, characterized in that, In step (3), the slurry concentration of the graded overflow product is 25%-35%.

5. The beneficiation method for recovering precious metals from copper-nickel ore using a multi-force field combined method according to claim 1, characterized in that, In step (3), the modifier 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, butylammonium black, and isoleucine; and the foaming agent includes one or more of terpineol, ammonium black, and methylpentanol.

6. The beneficiation method for recovering precious metals from copper-nickel ore using a multi-force field combined method according to claim 1, characterized in that, In step (4), the felt gravity separation equipment is a felt concentrator or a felt sluice, and the felt is a fiber gold panning cloth or a polyethylene gold panning cloth with a pile height greater than 10mm.

7. The beneficiation method for recovering precious metals from copper-nickel ore using a multi-force field combined method according to claim 1, characterized in that, In step (5), the 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 beneficiation method for recovering precious metals from copper-nickel ore using a multi-force field combined method according to claim 1, characterized in that, In step (5), the heavy medium separation process uses a heavy medium cyclone separator with a diameter of 100-200 mm.

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