A composite modifier for flotation of surface altered oxidized copper ore, its application and recovery method

Abstract

This invention relates to the field of copper oxide beneficiation technology, specifically a composite modifier for flotation of surface altered copper oxide ore, its application, and a recovery method. The composite modifier is composed of sodium pyrophosphite, PAC, sulfonated tannin, sodium lignin sulfonate, and sodium fluorosilicate. The weight ratio of sodium pyrophosphite, PAC, sulfonated tannin, sodium lignin sulfonate, and sodium fluorosilicate is: sodium pyrophosphite: PAC: sulfonated tannin: sodium lignin sulfonate: sodium fluorosilicate = 5~10:1~3:5~10:15~20:5~10. The composite modifier targets and interacts with the active sites on the surfaces of alkaline earth metal minerals and aluminosilicate minerals, selectively dispersing slime, inhibiting gangue minerals, eliminating slime adhesion to the copper mineral surface, and reducing the interference of slime on the interaction between copper minerals and reagents and flotation. The recovery method is stable and reliable, with high copper recovery rate, low cost, and easy process control, solving the technical problem of difficult beneficiation and recovery of surface altered copper oxide ore.

Description

Technical Field

[0001] This invention relates to the field of copper oxide beneficiation technology, and in particular to a composite modifier for flotation of surface altered copper oxide ore, its application, and a method for its recovery. Background Technology

[0002] Copper oxide resources are abundant; globally, copper oxide ore accounts for approximately 10-15% of all copper deposits, and copper metal content accounts for about 25% of total reserves. Copper oxide ore is difficult to beneficiate; only a very small portion of primary gangue types are easily beneficiated and recovered, achieving successful production practices. Most are located on the surface, and due to long-term weathering, water seepage, and alteration, they have incomplete crystal lattices, high silicification, and high slime content, resulting in poor copper mineral floatability. Some clay-type slimes adsorb copper ions well, making beneficiation and recovery difficult. The beneficiation technology for complex, altered, high-slime, and difficult-to-beneficiate copper oxide ores remains a global challenge.

[0003] Firstly, with the increasing depletion of sulfide and rich mineral resources, the development and utilization of oxide mineral resources is imperative. Secondly, with my country's socio-economic development, the demand for these resources continues to increase. However, under current technological conditions, my country has a severe shortage of mineral resources available for industrial mining and utilization. Domestically produced concentrates are insufficient to meet smelting and consumption needs, requiring large-scale imports. Breakthroughs in the technology for difficult-to-process copper oxides can reduce my country's dependence on copper imports. Thirdly, most complex altered, high-mud, difficult-to-process copper oxide resources are currently stalled due to economic and technical issues. Therefore, tackling these technical challenges and mastering the development technology to make their resource utilization economically and technically feasible is of great significance. Summary of the Invention

[0004] This invention provides a composite modifier for flotation of surface altered oxidized copper ore, its application, and a method for recovery, overcoming the shortcomings of the prior art and effectively solving the problem of difficult beneficiation and recovery of surface altered oxidized copper ore.

[0005] To solve the above problems, one of the technical solutions of the present invention is achieved through the following method: a composite modifier for flotation of surface altered oxidized copper ore, the composite modifier being composed of sodium pyrophosphite, PAC, sulfonated tannin, sodium lignin sulfonate, and sodium fluorosilicate; the weight ratio of sodium pyrophosphite, PAC, sulfonated tannin, sodium lignin sulfonate, and sodium fluorosilicate is: sodium pyrophosphite: PAC: sulfonated tannin: sodium lignin sulfonate: sodium fluorosilicate = 5~10: 1~3: 5~10: 15~20: 5~10.

[0006] The second technical solution of the present invention is achieved by the following method: the application of a composite modifier for flotation of surface altered copper oxide ore, which is used for the recovery of copper oxide in copper oxide ore.

[0007] The third technical solution of this invention is achieved through the following method: a method for recovering copper oxide from surface altered copper oxide ore using a composite modifier in flotation, comprising the following steps:

[0008] The first step, ore grinding and pulp pH adjustment: ore, pH adjuster, and water are fed into the mill for grinding, resulting in the dissociation of copper oxide minerals and gangue minerals; the grinding fineness is -0.074mm, with a content of 70-80%.

[0009] The second step is to adjust the slurry concentration of the grinding slurry obtained in the first step to 25-32% by adding water, and then add 500-900g / t of ore composite adjuster to suppress gangue minerals. At the same time, the sludge adhering to the surface of copper minerals is cleaned by the dispersing effect of the adjuster.

[0010] The third step is deep sulfidation of copper minerals: ammonium salts and sulfiding agents are added to the slurry adjusted in the second step, among which the NH4+ ion is positioned. + It is used to adsorb at active sites on mineral surfaces, increase the kinetic potential of copper oxide minerals, target and locate anions of sulfiding agents, and improve sulfidation efficiency and stability of sulfidation layers.

[0011] The fourth step is to eliminate the inhibitory effect of the sulfidation process: After the deep sulfidation in the third step, the strong reducing property of the residual sulfiding agent in the slurry reduces the redox potential of the slurry and inhibits the oxidation of copper minerals. The inhibitory effect of the sulfidation process is eliminated by adding a weak oxidizing agent to adjust the redox potential.

[0012] The fifth step is to collect and recover copper minerals: After the inhibition of the sulfidation process in the fourth step is eliminated, collectors and frothers are added, and the copper oxide ore is recovered by flotation using a conventional flotation process.

[0013] The pH adjuster mentioned above is lime or sodium hydroxide.

[0014] In the third step above, the amount of sulfiding agent used is 25%-50% of the copper metal content per ton of ore; the amount of ammonium salt used is 60%-100% of the amount of sulfiding agent used; the ammonium salt is ammonium sulfate or ammonium chloride; and the sulfiding agent is one of sodium sulfide, sodium hydrosulfide, or sodium polysulfide.

[0015] In the fourth step above, when the inhibitory effect of the sulfidation process is eliminated by adding a weak oxidant, the operation method varies depending on the type of weak oxidant. If the weak oxidant is a gas, the slurry is aerated; if the weak oxidant is a solid, a solution is prepared and added. The oxidant can be one of air, sodium persulfate, or ammonium persulfate.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. This invention addresses the technical challenges of difficult-to-process copper ore beneficiation due to weathering and water leaching, which weaken the activity of copper minerals due to the loss of metal ions from the copper mineral surface and the adsorption and self-activation of copper ions in gangue minerals. It also addresses the difficulties in separating and enriching copper minerals due to similar mineral floatability and worsening mud formation. This invention employs a composite modifier that targets the active sites on the surfaces of alkaline earth metal minerals and aluminosilicate minerals, selectively dispersing mud, inhibiting gangue minerals, eliminating mud adhesion to the copper mineral surface, and reducing the interference of mud on the interaction between copper minerals and reagents and flotation. Therefore, the recovery method of this invention is stable and reliable, with high copper recovery rate, low cost, and easy process control, solving the technical problem of difficult beneficiation and recovery of surface-altered copper ore. Furthermore, the composite modifier of this invention has the advantages of low toxicity and non-toxicity, good selectivity, good inhibition and dispersion effect on gangue minerals and mud, and low reagent cost.

[0018] 2. This invention utilizes the complexing properties of copper-ammonium to target and enhance the kinetic potential of copper minerals, attracting the anions of the sulfiding agent, thereby improving sulfidation efficiency and the stability of the sulfidation layer, achieving the goal of deep sulfidation.

[0019] 3. This invention eliminates the influence of residual sulfiding agents on the redox potential of the slurry through weak oxidation, eliminates the inhibitory effect of sulfiding agents in the deep sulfidation process, and indirectly improves the floatability of copper oxide minerals, thus providing a guarantee for subsequent efficient recovery. Attached Figure Description

[0020] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0021] Figure 1 This is a flowchart illustrating the copper oxide recovery method in an embodiment of the present invention. Detailed Implementation

[0022] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0023] Example 1: This embodiment of the invention discloses a composite modifier for flotation of surface altered oxidized copper ore. The composite modifier is composed of sodium metabiphosphite, PAC, sulfonated tannin, sodium lignosulfonate, and sodium fluorosilicate. The weight ratio of sodium metabiphosphite, PAC, sulfonated tannin, sodium lignosulfonate, and sodium fluorosilicate is: sodium metabiphosphite: PAC: sulfonated tannin: sodium lignosulfonate: sodium fluorosilicate = 5~10: 1~3: 5~10: 15~20: 5~10.

[0024] Example 2: This embodiment of the invention discloses the application of a composite modifier for flotation of surface altered copper oxide ore, which is used for the recovery of copper oxide from copper oxide ore.

[0025] Example 3: This embodiment of the invention discloses a method for recovering copper oxide from surface altered copper oxide ore using a composite modifier in flotation, comprising the following steps:

[0026] The first step, ore grinding and pulp pH adjustment: Ore, pH adjuster, and water are fed into the mill for grinding, resulting in the dissociation of copper oxide minerals and gangue minerals. The grinding fineness is -0.074mm, with 70-80% of the particles being finer. During grinding, the pH adjuster reacts fully with the pulp to adjust the pH of the ground product pulp to 7-9. The pH adjuster is a conventional pH adjuster, such as lime or sodium hydroxide.

[0027] The second step is to adjust the slurry concentration of the grinding slurry obtained in the first step to 25-32% by adding water, and then add 500-900g / t of ore composite adjuster to suppress gangue minerals. At the same time, the slurry is cleaned by the dispersing effect of the adjuster to remove the mud adhering to the surface of the copper minerals. The adjustment time for the slurry to suppress gangue is 3 minutes.

[0028] The third step is deep sulfidation of copper minerals: ammonium salts and sulfiding agents are added to the slurry adjusted in the second step, among which the NH4+ ion is positioned. + It is used to adsorb at active sites on the mineral surface, increase the kinetic potential of copper oxide minerals, target and locate the anions of the sulfiding agent, and improve the sulfidation efficiency and stability of the sulfidation layer; thereby achieving a deep sulfidation effect; the sulfidation time of the sulfiding agent is 2-3 minutes; among which, the ammonium salt is a conventional ammonium salt, such as ammonium sulfate, ammonium chloride, etc., and the sulfiding agent is a conventional sulfiding agent, such as sodium sulfide, sodium hydrosulfide, sodium polysulfide, etc.; the amount of sulfiding agent is 25%-50% of the copper metal content per ton of ore; the amount of ammonium salt is 60%-100% of the amount of sulfiding agent.

[0029] The fourth step is to eliminate the inhibitory effect of the sulfidation process: After the deep sulfidation in the third step, the strong reducing property of the residual sulfiding agent in the slurry reduces the redox potential of the slurry, which inhibits the oxidation of copper minerals. The inhibitory effect of the sulfidation process is eliminated by adding a weak oxidant to adjust the redox potential. The time for adding the weak oxidant to adjust the redox potential and eliminate the inhibitory effect of the sulfidation process is 2-5 minutes.

[0030] The fifth step is to collect and recover copper minerals: After the inhibition of the sulfidation process in the fourth step is eliminated, collectors and frothers are added, and the copper oxide ore is recovered by flotation using a conventional flotation process.

[0031] In the fourth step, when the inhibitory effect of the sulfidation process is eliminated by adding a weak oxidant, the operation method varies depending on the type of weak oxidant. If the weak oxidant is a gas, the slurry is aerated; if the weak oxidant is a solid, a solution is prepared and added. The oxidant can be one of air, sodium persulfate, or ammonium persulfate.

[0032] Example 2: A copper mine in Xinjiang has surface-covered copper oxide ore with a copper grade of 1.02% and an oxidation rate of 93.40%. Of this, free copper oxide accounts for 72.20%, and bound copper oxide for 21.20%. The gangue minerals are mainly epidote, garnet, potassium feldspar, calcite, and dolomite. Conventional sulfide flotation yields only 28% copper recovery, and stockpiling poses too high an environmental risk. Therefore, a copper oxide flotation recovery experiment was conducted. Details are as follows:

[0033] The compound modifier formulation ratio is: sodium metabisulfite: PAC: sulfonated tannin: sodium lignosulfonate: sodium fluorosilicate = 7:3:10:15:5. Add 7 units of sodium metabisulfite, 3 units of PAC, 10 units of sulfonated tannin, 15 units of sodium lignosulfonate, and 5 units of sodium fluorosilicate to a beaker, then add 960 units of water and stir to dissolve, preparing a 4% concentration for addition.

[0034] First, add 200g / t of ore lime to the ore, then add water milling until the fineness is -0.074mm, accounting for 80%.

[0035] Add water to the grinding slurry to adjust the slurry concentration to 32%, add 500g / t of compound modifier to the ore, and adjust the slurry for 3 minutes.

[0036] Add 1500g / t ammonium sulfate from the ore and 2600g / t sodium hydrosulfide from the ore, and perform deep sulfidation for 3 minutes.

[0037] Add 100g / t of sodium sulfide to the ore and eliminate the inhibition of copper minerals by residual sodium hydrosulfide in the slurry for 2 minutes.

[0038] By adding 30 g / t alkyloxime acid and 200 g / t pentyl xanthate as collectors, and 50 g / t No. 2 oil as frother, a copper concentrate with a copper grade of 18.89% and a recovery rate of 63.56% was finally produced through one roughing, two cleaning, and one scavenging process. This achieved efficient recovery of the ore.

[0039] Example 3: A copper-gold-silver deposit in Kyrgyzstan, with a copper grade of 0.68%, an oxidation rate of 98.54%, free copper oxide accounting for 76.44%, bound copper oxide accounting for 22.10%, a gold grade of 1.5 g / t, and a silver grade of 5.2 g / t. The gangue minerals are mainly diopside and garnet, and also contain large amounts of talc, chlorite, and serpentine. A comprehensive copper-gold-silver recovery study was conducted, as detailed below:

[0040] The compound modifier formulation ratio is: sodium metabiphosphite: PAC: sulfonated tannin: sodium lignosulfonate: sodium fluorosilicate = 10:2:5:20:10. The preparation method is described in Example 2.

[0041] First, add 500g / t of ore lime to the ore, then add water milling until the fineness is -0.074mm, accounting for 70%.

[0042] Add water to the grinding slurry to adjust the slurry concentration to 27%, add 40g / t of MIBC ore for desliming flotation, add 800g / t of composite modifier to the bottom of the desliming flotation cell, and adjust the slurry for 3 minutes.

[0043] Add 1000g / t ammonium sulfate and 1600g / t sodium hydrosulfide from the ore, and perform deep sulfidation for 2 minutes.

[0044] Add air and agitate to eliminate the inhibition of copper minerals by residual sodium hydrosulfide in the slurry for 5 minutes.

[0045] By adding 20 g / t of butylammonium black powder, 220 g / t of pentyl xanthate, and 25 g / t of kerosene as collectors, and 10 g / t of MIBC as frother, the final concentrate produced after two roughing processes, two cleaning processes, and one scavenging process yielded a copper grade of 16.02% with a recovery rate of 46.56%, a gold grade of 48.69 g / t with a recovery rate of 64.15%, and a silver grade of 94.5 g / t with a recovery rate of 58.36%, achieving efficient recovery of the ore resources.

[0046] Example 4: A copper-gold mine in Kyrgyzstan has a copper grade of 0.42%, an oxidation rate of 99.01%, 82.61% free copper oxide, 6.40% bound copper oxide, a gold grade of 2.85 g / t, and a gold content of 5.2 g / t. The gangue minerals are mainly hematite, limonite, and quartz. A comprehensive copper-gold recovery study was conducted on this mine, as detailed below:

[0047] The compound modifier ratio is: sodium metabiphosphite: PAC: sulfonated tannin: sodium lignosulfonate: sodium fluorosilicate = 5:1:7:18:6. The preparation method is the same as in Example 2.

[0048] First, add 300g / t of sodium hydroxide to the ore and grind it with water until the fineness is -0.074mm, accounting for 75%.

[0049] Add water to the grinding slurry to adjust the slurry concentration to 27%, add 650g / t of composite modifier to the ore, and adjust the slurry for 3 minutes.

[0050] Add 1700g / t ammonium sulfate and 1700g / t sodium sulfide from the ore, and perform deep sulfidation for 3 minutes.

[0051] Add air and agitate to eliminate the inhibition of copper minerals by residual sodium hydrosulfide in the slurry for 5 minutes.

[0052] Then, 50 g / t of butyl ammonium black powder, 120 g / t of butyl xanthate, and 15 g / t of light white oil were added as collectors, and 20 g / t of No. 2 oil was added as a frother. After two roughing, two cleaning and one scavenging processes, the final concentrate produced had a copper grade of 11.04% and a recovery rate of 61.21%, and a gold grade of 88.19 g / t and a recovery rate of 72.06%.

[0053] Example 5: A copper oxide mine in Tibet, with a copper grade of 1.85% and an oxidation rate of 72.00%, containing 50.32% free copper oxide and 21.68% bound copper oxide. The gangue mineral is mainly amphibole. A recovery study was conducted, as detailed below:

[0054] The compound modifier ratio is: sodium metabiphosphite: PAC: sulfonated tannin: sodium lignosulfonate: sodium fluorosilicate = 8:2:8:16:7. The preparation method is the same as in Example 1.

[0055] First, add 1000g / t of sodium carbonate to the ore and grind it with water until the fineness is -0.074mm, accounting for 70%.

[0056] Add water to the grinding slurry to adjust the slurry concentration to 27%, add 750g / t of composite modifier, and adjust the slurry for 3 minutes.

[0057] Add 3300g / t ammonium sulfate from the ore and 5000g / t sodium polysulfide from the ore, and perform deep sulfurization for 3 minutes.

[0058] Add air and agitate to eliminate the inhibition of copper minerals by residual sodium hydrosulfide in the slurry for 4 minutes.

[0059] Add 120g / t butyl xanthate and 20g / t thiazole as collectors, and 30g / t 2# oil as frother. Through two roughing, two cleaning and two scavenging processes, the final concentrate produced has a copper grade of 23.04% and a recovery rate of 67.45%.

[0060] Example 6: A copper oxide mine in Tibet, with a copper grade of 0.78%, an oxidation rate of 85.29%, free copper oxide accounting for 82.19%, and bound copper oxide accounting for 3.10%. The gangue minerals are mainly diopside, quartz, and epidote. A recovery study was conducted, as detailed below:

[0061] The compound modifier formulation ratio is: sodium metabiphosphite: PAC: sulfonated tannin: sodium lignosulfonate: sodium fluorosilicate = 9:1:6:15:5. The preparation method is the same as in Example 1.

[0062] First, add 200g / t of ore lime to the ore and grind it with water until the fineness is -0.074mm, accounting for 74%.

[0063] Add water to the grinding slurry to adjust the slurry concentration to 31%, add 800g / t of composite modifier to the ore, and adjust the slurry for 3 minutes.

[0064] Add 1500g / t ammonium sulfate from the ore and 2000g / t sodium polysulfide from the ore, and perform deep sulfurization for 2 minutes.

[0065] Add 150g / t of sodium sulfide to the ore to eliminate the inhibition of copper minerals by residual sodium hydrosulfide in the slurry for 3 minutes.

[0066] Add 120 g / t butyl xanthate and 30 g / t salicylic acid as collectors, and 30 g / t MIBC as frother. Through one roughing, two cleaning and two scavenging processes, the final concentrate produced has a copper grade of 21.16% and a recovery rate of 54.29%.

[0067] This invention is widely applicable to the comprehensive recovery of copper, gold, and silver when gold and silver are associated with ores, and when the ores are copper oxide gold ore, copper oxide silver ore, or gold-silver-copper ore.

[0068] In summary, this invention addresses the technical challenges of difficult-to-process copper ore beneficiation due to weathering and water leaching. These challenges include the loss of metal ions from the copper mineral surface, weakening its activity, and the adsorption and self-activation of copper ions in gangue minerals. Furthermore, the similarity of mineral floatability and the deterioration of mud formation further complicate the beneficiation and enrichment of copper minerals. This invention employs a composite modifier that targets the active sites on the surfaces of alkaline earth metal minerals and aluminosilicate minerals. This selectively disperses mud, inhibits gangue minerals, eliminates mud adhesion to the copper mineral surface, and reduces the interference of mud on the interaction between copper minerals and reagents, as well as flotation. Therefore, this invention provides a stable and reliable recovery method with high copper recovery, low cost, and easy process control, solving the technical problem of difficult beneficiation and recovery of surface-altered copper ore. Moreover, the composite modifier of this invention has the advantages of low toxicity, good selectivity, good inhibition and dispersion effects on gangue minerals and mud, and low reagent cost.

[0069] Furthermore, this invention utilizes the complexing properties of copper-ammonium to target and enhance the kinetic potential of copper minerals, attracting the anions of the sulfiding agent, thereby improving sulfidation efficiency and the stability of the sulfidation layer, achieving the goal of deep sulfidation.

[0070] Furthermore, this invention eliminates the influence of residual sulfiding agents on the redox potential of the slurry through a weak oxidation method, eliminates the inhibitory effect of sulfiding agents in the deep sulfidation process, and indirectly improves the floatability of copper oxide minerals, thus providing a guarantee for subsequent efficient recovery.

Claims

1. A method for recovering copper oxide from surface altered copper oxide ore using a composite modifier in flotation, characterized in that, This compound modifier is composed of sodium pyrophosphite, PAC, sulfonated tannin, sodium lignosulfonate, and sodium fluorosilicate. The method includes the following steps: The first step, ore grinding and pulp pH adjustment: ore, pH adjuster, and water are fed into the mill for grinding, resulting in the dissociation of copper oxide minerals and gangue minerals; the grinding fineness is -0.074mm, with a content of 70-80%. The second step is to adjust the slurry concentration of the grinding slurry obtained in the first step to 25-32% by adding water, and then add 500-900g / t of ore composite adjuster to suppress gangue minerals. At the same time, the sludge adhering to the surface of copper minerals is cleaned by the dispersing effect of the adjuster. The third step is deep sulfidation of copper minerals: ammonium salts and sulfiding agents are added to the slurry adjusted in the second step, among which the NH4+ ion is positioned. + It is used to adsorb at active sites on mineral surfaces, increase the kinetic potential of copper oxide minerals, target and locate anions of sulfiding agents, and improve sulfidation efficiency and stability of sulfidation layers. The fourth step is to eliminate the inhibitory effect of the sulfidation process: After the deep sulfidation in the third step, the strong reducing property of the residual sulfiding agent in the slurry reduces the redox potential of the slurry and inhibits the oxidation of copper minerals. The inhibitory effect of the sulfidation process is eliminated by adding a weak oxidizing agent to adjust the redox potential. The fifth step is to collect and recover copper minerals: After the inhibition of the sulfidation process in the fourth step is eliminated, collectors and frothers are added, and the copper oxide ore is recovered by flotation using a conventional flotation process.

2. The method for recovering copper oxide from surface altered copper oxide ore flotation using a composite modifier according to claim 1, characterized in that, The weight ratio of sodium pyrophosphite, PAC, sulfonated tannin, sodium lignosulfonate, and sodium fluorosilicate in the composite modifier is: sodium pyrophosphite: PAC: sulfonated tannin: sodium lignosulfonate: sodium fluorosilicate = 5~10: 1~3: 5~10: 15~20: 5~10.

3. The method for recovering copper oxide from surface altered copper oxide ore flotation using a composite modifier according to claim 1, characterized in that, The pH adjuster is lime or sodium hydroxide.

4. The method for recovering copper oxide from surface altered copper oxide ore flotation using a composite modifier according to claim 1, characterized in that, In the third step, the amount of sulfiding agent used is 25%-50% of the copper metal content per ton of ore; the amount of ammonium salt used is 60%-100% of the amount of sulfiding agent used; the ammonium salt is ammonium sulfate or ammonium chloride; and the sulfiding agent is one of sodium sulfide, sodium hydrosulfide, or sodium polysulfide.

5. The method for recovering copper oxide from surface altered copper oxide ore flotation using a composite modifier according to claim 1, characterized in that, In the fourth step, when the inhibitory effect of the sulfidation process is eliminated by adding a weak oxidant, the operation method varies depending on the type of weak oxidant. If the weak oxidant is a gas, the slurry is aerated; if the weak oxidant is a solid, a solution is prepared and added. The oxidant can be one of air, sodium persulfate, or ammonium persulfate.

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