A method for recovering copper resources from copper oxide ore by reverse flotation separation

Abstract

The application discloses a method for recovering copper resources from oxidized copper ore by reverse flotation, and belongs to the technical field of ore dressing. The method comprises the following steps: after grinding and slurry preparation of the oxidized copper ore, desulfurization flotation is firstly performed, and then decalcium magnesium reverse flotation is performed by using flotation reagents containing an oxidized copper ore depressant (starch xanthate) and a calcium-magnesium carbonate mineral collector, the foam product is a calcium-magnesium carbonate tailing, and the underflow product is an oxidized copper concentrate. The method realizes efficient and low-cost separation of the oxidized copper ore and calcium-magnesium carbonate gangue minerals by using starch xanthate as the oxidized copper ore depressant and combining the "asynchronous separation-reverse flotation" process, fills the technical blank of the "asynchronous separation-reverse flotation" of the oxidized copper ore in the prior art, and has the advantages of wide sources of the flotation reagents, green environmental protection, a simple process, remarkable separation effect and the like.

Description

Technical Field

[0001] This invention relates to a mineral processing method, and more particularly to a method for separating and recovering copper resources from copper oxide ore by reverse flotation, belonging to the field of mineral processing technology. Background Technology

[0002] Copper oxide ores (such as malachite, azurite, and chrysocolla) are an important component of copper resources. With the increasing depletion of easily beneficiated copper sulfide ores, copper oxide ores and copper-cobalt oxide ores have gradually become important targets for copper and cobalt resource development. Because copper oxide minerals generally exhibit characteristics such as easy mud formation, high surface solubility, and strong polarity, and are often associated with large amounts of calcium magnesium carbonate gangue minerals such as dolomite and calcite, resulting in complex ore structures and fine-grained dispersals, their flotation separation has always been a technical challenge in the mineral processing field. Traditional methods for processing copper oxide ores typically employ direct flotation, which involves first activating the surface of the copper oxide ores with sulfiding agents such as sodium sulfide, followed by enrichment using xanthate collectors. For example, Chinese patent CN112191370B discloses a method that modifies the surface of copper minerals using a sulfidation activator containing both reducing and sulfiding agents, followed by flotation separation using copper mineral collectors such as xanthates to obtain copper concentrate and flotation tailings. This method can improve and control the formation process of the sulfide film on the surface of copper minerals, achieving efficient flotation enrichment of mixed copper minerals and copper oxide ores. However, when dealing with complex and difficult-to-process copper oxide ores with high calcium and magnesium content, direct flotation often suffers from poor selectivity, high reagent consumption, and severe gangue entrainment. Furthermore, the high content of calcium and magnesium carbonate gangue in the obtained concentrate leads to high acid consumption and high production costs in subsequent leaching. Currently, the flotation enrichment of copper oxide ores globally is dominated by direct flotation. There are no publicly reported or industrial application precedents for asynchronous separation-reverse flotation in the field of copper oxide ores, which represents a technological gap in this mineral processing field.

[0003] Reverse flotation (using depressants to retain target minerals in the underflow while collectors float gangue minerals) is an effective way to reduce gangue content and improve concentrate quality, and it has been successfully applied in iron ore and phosphate ore fields. However, asynchronous separation-reverse flotation is still a blank in the field of copper oxide ores, and there are no industrial precedents for asynchronous separation-reverse flotation of copper oxide ores, either domestically or internationally. The fundamental reason is that the success of reverse flotation depends on the availability of highly efficient and selective copper oxide mineral depressants. These depressants must be able to be directionally anchored on the surface of copper oxide minerals in the aqueous medium, achieving selective retention of copper minerals while allowing calcium and magnesium carbonate gangue minerals to float freely. Currently, commonly used industrial depressants such as water glass, polyacrylic acid, and carboxymethyl cellulose have insufficient selective inhibition capabilities for copper oxide minerals, making it difficult to meet the stringent requirements for depressant performance in the reverse flotation of high-calcium and magnesium copper oxide ores.

[0004] Starch has the characteristics of large molecular weight and good hydrophilicity, but it lacks specific binding sites for copper ions and cannot be directly used as an inhibitor of copper oxide minerals. Therefore, how to perform targeted chemical modification of starch, while maintaining the highly hydrophilic shielding shell of starch macromolecules, introduce specific functional groups with the ability to target copper lattice chemically, is the key to breaking through the technical bottleneck of reverse flotation process of copper oxide ore. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method for separating and recovering copper resources from copper oxide ore by reverse flotation. This method utilizes starch xanthate as a depressant for copper oxide ore and combines it with an asynchronous separation-reverse flotation process to achieve efficient and low-cost separation of copper oxide minerals from calcium magnesium carbonate gangue minerals. This fills the technological gap in the existing technology of asynchronous separation-reverse flotation for copper oxide ore. This method has the advantages of wide availability of flotation reagents, being environmentally friendly, having a simple process, and achieving significant separation results.

[0006] To achieve the above-mentioned technical objectives, the present invention provides a method for separating and recovering copper resources from copper oxide ore by reverse flotation. This method involves grinding and slurry conditioning the copper oxide ore, followed by desulfurization flotation using flotation reagents including a sulfide mineral collector to obtain a sulfur concentrate and desulfurized tailings. The desulfurized tailings are then subjected to decalcification and magnesium removal reverse flotation using flotation reagents including a copper oxide ore depressant and a calcium magnesium carbonate mineral collector. The froth product is the calcium magnesium carbonate tailings, and the underflow product is the copper oxide concentrate. The copper oxide ore depressant is starch xanthate.

[0007] This invention enables the separation of copper oxide ore from calcium magnesium carbonate using an asynchronous separation-reverse flotation process. The key lies in the use of starch xanthate as a copper oxide ore inhibitor. The unique molecular structure of starch xanthate is characterized by its main chain being a hydrophilic, high-molecular-weight starch chain, with numerous xanthic acid groups (-CSS) grafted onto the starch main chain. - The sulfur atom in the xanthate group has high polarizability and belongs to the soft base in coordination chemistry. It can react with soft copper ions (Cu) on the surface of copper oxide minerals. + / Cu 2+The process involves directional chelation between soft acids and soft bases, forming a robust quaternary chelate network. This allows the macromolecule to cross the hydration layer and precisely anchor itself on the surface of copper minerals. Simultaneously, a large number of unreacted free hydroxyl groups (-OH) on the starch backbone are exposed in the slurry, forming a dense hydrogen bond network with water molecules. This reconstructs a hydration protective film on the surface of the copper minerals. Furthermore, the three-dimensional network of starch chains creates a steric hindrance effect, physically and chemically preventing the calcium magnesium carbonate mineral collector from approaching and capturing copper oxide minerals. This creates a significant difference in flotation capacity between copper oxide minerals and calcium magnesium carbonate gangue minerals, causing the copper minerals to be retained in the underflow while the calcium magnesium carbonate gangue minerals float to the surface with the foam, achieving selective separation between the two.

[0008] As a preferred embodiment, the starch xanthate has the following molecular structural expression:

[0009] ;

[0010] In this designation, [C6H7O2] represents the dehydrated glucose unit, n is the degree of polymerization of the dehydrated glucose unit, OCSSM is the xanthic acid group, x is the degree of substitution of the xanthic acid group (x = 0.03~0.07), and M is a hydrogen proton or cation. The xanthic acid group is introduced as a functional group for directional chelation with copper ions on the surface of copper oxide minerals. If the degree of substitution of the xanthic acid group on the starch backbone is low, its ability to interact with the surface of copper oxide minerals is weak; if the degree of substitution of the xanthic acid group on the starch backbone is high, it will occupy too many hydrophilic hydroxyl groups, reducing the hydrophilicity of the starch. M is further preferably a sodium ion.

[0011] As a preferred embodiment, the degree of polymerization (n) of the dehydrated glucose unit ranges from 100 to 2000. Within this preferred range, starch xanthate exhibits characteristics such as low viscosity and high fluidity, meeting the application requirements as an inhibitor of copper oxide ore. The degree of polymerization (n) of the dehydrated glucose unit is further preferably ranged from 200 to 800. As a preferred embodiment, the grinding process controls the fineness to be such that the mass percentage of particles smaller than 200 mesh is 50% to 90%. Grinding to an appropriate particle size facilitates the dissociation of copper oxide ore from calcium magnesium carbonate minerals.

[0012] As a preferred embodiment, the pulp conditioning process adjusts the pulp concentration to 15-45% and the pH to 6.5-8.5. Pulp conditioning provides a suitable pulp concentration and pH environment for desulfurization flotation.

[0013] As a preferred embodiment, the desulfurization flotation includes one roughing stage and at least one cleaning stage.

[0014] As a preferred embodiment, the reagent regime for roughing is as follows: the dosage of sulfide ore collector is 50-200g per ton of raw ore; the dosage of frother is 10-20g per ton of raw ore; the sulfide ore collector includes xanthate collectors; the frother includes No. 2 oil; and the cleaning process is blank cleaning. Conventional xanthate collectors, such as butyl xanthate, can be used for desulfurization flotation.

[0015] As a preferred embodiment, the roughing tailings and cleaning tailings from the desulfurization flotation are combined into desulfurization tailings and then enter the calcium-magnesium carbonate reverse flotation process.

[0016] As a preferred embodiment, the decalcification and magnesium reverse flotation includes at least one roughing stage.

[0017] As a preferred embodiment, the reagent system for the roughing process is as follows: for the first roughing process, the dosage of copper oxide ore inhibitor is 500g to 2000g per ton of raw ore, and the dosage of calcium magnesium carbonate mineral collector is 100g to 1000g per ton of raw ore; for the second and subsequent roughing processes, the reagent dosage is reduced relative to the first roughing process.

[0018] As a preferred embodiment, the calcium magnesium carbonate mineral collector is a fatty acid collector. Examples of fatty acid collectors include sodium oleate.

[0019] The starch xanthate of this invention is prepared by the following method: Soluble starch (or native starch) is slowly added to a reactor equipped with deionized water and a mechanical stirrer, condenser, and tail gas absorption device. The mixture is stirred and dispersed at 300–600 r / min and kept at 50–60 °C for 30–60 min to form a uniform starch solution or stable dispersion. The solution is then cooled to 20–25 °C. Sodium hydroxide is dissolved in deionized water and, after cooling to room temperature, is slowly added dropwise to the starch solution system over 10–20 min, maintaining the temperature at 20–25 °C. After the addition is complete, stirring continues for 20–40 min to alkalize some of the hydroxyl groups in the starch molecules, forming sodium starch alcohol. The reaction system is then cooled to 15–20 °C. Under effective ventilation, condensation recovery, and safe pressure relief conditions, carbon disulfide is slowly added over 15–30 min, controlling the system temperature not to exceed 25 °C during the addition process. After the addition is complete, the reaction is continued at 20–25 °C for 0.5–2 minutes of stirring. h, the reaction produces sodium starch xanthate; after the reaction, rinse the feeding device with a small amount of deionized water and add the rinsing liquid to the reaction system, add an appropriate amount of deionized water, and continue stirring for 15-30 minutes for homogenization, controlling the pH of the resulting reaction solution to be no lower than 8.5, without acidification treatment, and finally filter through a 100-200 mesh alkali-resistant filter to remove undissolved particles, gels and mechanical impurities, thus obtaining a uniform light yellow to yellow sodium starch xanthate inhibitor stock solution. The obtained stock solution should be protected from light, sealed and preferably prepared and used immediately. The mass ratio of soluble starch to sodium hydroxide and carbon disulfide is 1:(0.1-1.5):(0.1-1.5).

[0020] This invention involves gelatinizing and alkalizing soluble starch in a sodium hydroxide solution, and then, under strong alkali and a set temperature, performing in-situ alkaline hydrolysis to selectively control the degree of polymerization of natural starch macromolecules from thousands to a target range, thereby obtaining a low-viscosity, high-flowability, and controllable degree of polymerization sodium starch alkoxide colloid. Subsequently, the sodium starch alkoxide colloid is cooled and then subjected to a xanthate grafting reaction with carbon disulfide. After the reaction is completed, starch xanthate stock solution is obtained.

[0021] The specific steps for separating and recovering copper resources from copper oxide ore according to this invention are as follows: (1) Grinding and slurry preparation: Grind the copper oxide ore to a fineness of less than 200 mesh with a mass of 50% to 90%, add water to prepare a slurry with a mass concentration of 15% to 45%, and adjust the pH value of the slurry to 6.5 to 8.5; (2) Flotation desulfurization: Add sulfide mineral collector butyl xanthate to the slurry, the amount of which is 50~200g per ton of raw ore, and stir for 3~5 minutes; then add frother No. 2 oil (dosage 10~20g / t), stir evenly and then carry out one roughing operation to obtain roughing froth product and roughing underflow product; (3) Sulfur concentrate is obtained by fine selection: the froth product from roughing is introduced into the fine selection area and fine selection is carried out 3 to 5 times. The final froth product is the sulfur concentrate. The fine selection underflow product and the roughing underflow product are combined and put into the calcium-magnesium de-flotation operation. (4) Decalcification and magnesium reverse flotation: Add starch xanthate stock solution (added in stock solution form, measured by dry basis mass) to the combined slurry, the amount added is 500~2000g per ton of raw ore, and stir for 3~5min; then add calcium magnesium carbonate mineral collector, the collector is a fatty acid collector, the amount added is 100~1000g per ton of raw ore, and stir for 3~5min; carry out 2~3 roughing operations, the final froth product is calcium magnesium carbonate gangue tailings, and the bottom flow product is copper oxide or copper-cobalt oxide concentrate.

[0022] The copper oxide ore in this invention refers to a single copper oxide ore or a copper oxide cobalt ore associated with cobalt copper, etc.

[0023] Compared with the prior art, the outstanding substantive features and significant progress of the present invention are as follows:

[0024] (1) This invention breaks through the technical inertia of the long-term adherence to the positive flotation process in the field of copper oxide ore. For the first time, the step-by-step process of "preferential flotation desulfurization - reverse flotation to suppress copper" is successfully applied to the flotation separation of copper oxide ore, opening up a brand-new technical route of asynchronous separation-reverse flotation of copper oxide ore, which is of pioneering significance.

[0025] (2) This invention is the first to use starch xanthate as a flotation inhibitor for copper oxide minerals. By utilizing the specific chelating ability of its xanthate group for copper ions and the synergistic effect of the strong hydrophilicity and steric hindrance of the macromolecular skeleton, it achieves highly efficient and selective inhibition of copper oxide minerals, providing a new paradigm for the application of natural polymers in the field of flotation reagents.

[0026] (3) In the process of beneficiation of copper oxide ore, the asynchronous separation-reverse flotation process of copper oxide ore and the starch xanthate inhibitor complement each other. Reverse flotation provides the best stage for the inhibitor to exert selective inhibition, while the new inhibitor provides a fundamental guarantee for the successful application of reverse flotation in copper oxide ore. The coupling of the two realizes the classification, enrichment and recovery of copper sulfide and copper oxide, significantly improves the total copper recovery rate of the whole process, and greatly reduces the calcium and magnesium content of the concentrate.

[0027] (4) The starch xanthate used in the copper oxide ore beneficiation process of the present invention is made from natural starch, which is widely available, inexpensive and biodegradable, thus avoiding the environmental pollution problems of traditional highly toxic inhibitors. Attached Figure Description

[0028] Figure 1 Gel permeation chromatography (GPC) of the starch xanthate inhibitor stock solution.

[0029] Figure 2 This is a schematic diagram of the process for recovering copper oxide ore by flotation using the "asynchronous separation-reverse flotation" process of the present invention. Detailed Implementation

[0030] The following specific embodiments are intended to further illustrate the content of the present invention, but are not intended to limit the scope of protection of the claims of the present invention.

[0031] In the following specific embodiments, the starch xanthate inhibitor stock solution was prepared by the following method: Specifically, 40.0 g of soluble starch was weighed on a dry basis and slowly added to a reactor equipped with a mechanical stirrer, condenser, and tail gas absorption device containing approximately 300 mL of deionized water. The mixture was stirred and dispersed at 400 r / min and kept at 55°C for 40 min to form a uniform starch solution or stable dispersion. The solution was then cooled to 25°C. Separately, 5.0 g of sodium hydroxide was dissolved in approximately 50 mL of deionized water, cooled to room temperature, and slowly added dropwise to the starch system over 15 min, maintaining the temperature at 25°C. After the addition was complete, stirring continued for 30 min to alkalize some of the hydroxyl groups in the starch molecules, forming sodium starch alcohol. The reaction system was then cooled to 20°C. Under effective ventilation, condensation recovery, and safe pressure relief conditions, 5.0 g of carbon disulfide was slowly added over 20 min. During the addition process, the system temperature was controlled to not exceed 25°C. After the addition was completed, the reaction was continued at 20°C with stirring for 1 h to produce sodium starch xanthate. After the reaction, the feeding device was rinsed with a small amount of deionized water, and the rinsing liquid was added back into the reaction system. Deionized water was added to make the total water volume approximately 360 mL. The mixture was stirred for another 20 min for homogenization. The pH of the resulting reaction solution was controlled at 10 without acidification. Finally, the solution was filtered through a 200-mesh alkali-resistant filter to remove undissolved particles, gel, and mechanical impurities, yielding a uniform pale yellow to yellow sodium starch xanthate inhibitor stock solution. The obtained stock solution should be protected from light, sealed, and preferably prepared and used immediately. The elemental analysis of the sodium starch xanthate of this invention is shown in Table 1 below, and the gel permeation chromatography is as follows. Figure 1 As shown in Table 2.

[0032] Table 1. Results of Organic Elemental Analyzer (EA) Tests

[0033] Table 2. Gel permeation chromatography (GPC) detection results

[0034] In the following examples and comparative examples, the recovery rate of each metal element is calculated based on the corresponding product yield, the metal element grade in the product, and the metal element grade in the feed, i.e., metal element recovery rate = product yield × metal element grade in the product / metal element grade in the feed. In some cases, the cobalt grade test results have few significant figures; therefore, the corresponding cobalt recovery rate is calculated approximately based on the listed grades. The slight metal balance deviation caused by rounding down the grade values ​​is considered a rounding error.

[0035] Example 1

[0036] The oxidized ore raw material used in this embodiment is a copper-cobalt oxide ore with a copper grade of 2.59%, a cobalt grade of 0.096%, a calcium grade of 9.94%, and a magnesium grade of 6.96%. The main useful minerals are malachite, azurite, and chalcocite, the main cobalt mineral is cobaltite, and the main calcium-magnesium carbonate gangue minerals are calcite and dolomite, with a small amount of quartz and clay minerals.

[0037] Adopting such Figure 2 The open-circuit test was conducted on the stepwise flotation process shown in the figure. The specific steps are as follows:

[0038] (1) Grinding and slurry preparation: After crushing the ore to -2mm (through a 2mm screen), it is ground. The grinding fineness is controlled to -200 mesh (through a 200 mesh screen) with a mass ratio of 78%. Water is added to adjust the slurry concentration to 30wt%, and sodium carbonate is used to adjust the pH value of the slurry to 7.5.

[0039] (2) Priority flotation of sulfur: 200 g / t of sulfide collector butyl xanthate is added to the slurry based on the dry weight of each ton of raw ore, and stirred for 3 min; then 15 g / t of frother No. 2 oil is added, stirred evenly, and then aerated for flotation. The froth is scraped for 5 min to obtain the roughing froth product and the roughing underflow product.

[0040] (3) Sulfur concentrate is obtained by fine selection: the roughing froth product is subjected to three fine selection operations (all of which are blank fine selection), and the final froth product is the sulfur concentrate; the underflow product generated by fine selection is returned to the previous stage operation in sequence, and the final middlings and roughing underflow product are combined into the calcium-magnesium de-flotation operation.

[0041] (4) Decalcification and magnesium reverse flotation: Add 1500 g / t of starch xanthate inhibitor stock solution (measured as starch xanthate) to the combined slurry and stir for 4 min. Add 1000 g / t of sodium oleate collector, stir for 3 min, and then perform the first roughing process, skimming the foam for 5 min. Add 800 g / t of starch xanthate inhibitor stock solution and 200 g / t of sodium oleate collector to the foam product of the first roughing process, and perform the second roughing process, skimming the foam for 5 min. The foam products from the two roughing processes are combined to form calcium magnesium carbonate gangue tailings, and the final underflow product is copper oxide cobalt concentrate.

[0042] The flotation test results are as follows:

[0043] The yield of sulfur concentrate was 8.13%, the grade of calcium was 7.29% with a calcium recovery rate of 5.96%, the grade of magnesium was 6.67% with a magnesium recovery rate of 7.80%, the grade of copper was 15.80% with a copper recovery rate of 49.58%, and the grade of cobalt was 0.15% with a cobalt recovery rate of 12.64%.

[0044] The tailings yield is 22.30%, the overall calcium grade is approximately 14.30% with a calcium recovery rate of 32.09%, the overall magnesium grade is approximately 9.20% with a magnesium recovery rate of 29.49%, the overall copper grade is approximately 0.80% with a copper recovery rate of 6.92%, and the overall cobalt grade is approximately 0.067% with a cobalt recovery rate of 15.24%.

[0045] The yield of copper oxide cobalt concentrate was 69.57%, the calcium grade was 8.85% with a calcium recovery rate of 61.95%, the magnesium grade was 6.27% with a magnesium recovery rate of 62.71%, the copper grade was 1.62% with a copper recovery rate of 43.49%, and the cobalt grade was 0.10% with a cobalt recovery rate of 72.12%.

[0046] The total copper recovery rate of the sulfur concentrate and copper-cobalt oxide concentrate was 93.07%, and the total cobalt recovery rate of the sulfur concentrate and copper-cobalt oxide concentrate was 84.76%.

[0047] Comparative Example 1

[0048] This comparative example uses copper-cobalt oxide ore feedstock from the same mine and batch as in Example 1. The measured copper grade in this experiment was 3.07%, cobalt grade was 0.11%, calcium grade was 9.41%, and magnesium grade was 6.72%. This comparative example uses a traditional forward flotation process, namely the sulfide-xanthate flotation method: the experiment employs a "sulfide-oxygenation first" flotation process. In the sulfide ore flotation section, a "one rougher, three cleaners" process is set up to improve the recovery rate of sulfide minerals and ensure the stability of concentrate grade; in the oxide ore flotation section, a "three-stage scavenging" process is used. The "asynchronous separation-reverse flotation process" and starch xanthate inhibitor of this invention are not used.

[0049] The specific process conditions are as follows: the grinding fineness meets the requirement that the mass ratio of -200 mesh particles is 70%; 200 g / t of butyl xanthate and 15 g / t of No. 2 oil are added in the roughing stage; no reagents are added in the cleaning stage; the scavenging stage is carried out in three stages: 800 g / t of sodium hydrosulfide sulfide, 1000 g / t of butyl xanthate collector and 15 g / t of No. 2 oil are added in the first stage; 400 g / t of sulfide, 150 g / t of collector and 15 g / t of No. 2 oil are added in the second stage; and 200 g / t of sulfide, 100 g / t of collector and 15 g / t of No. 2 oil are added in the third stage.

[0050] The flotation test results are as follows:

[0051] The yield of sulfur concentrate was 9.14%, the grade of calcium was 6.58% with a calcium recovery rate of 6.39%, the grade of magnesium was 5.80% with a magnesium recovery rate of 7.89%, the grade of copper was 16.10% with a copper recovery rate of 47.86%, and the grade of cobalt was 0.19% with a cobalt recovery rate of 15.68%.

[0052] The tailings yield is 49.56%, the comprehensive calcium grade is approximately 14.59% with a calcium recovery rate of 76.81%, the comprehensive magnesium grade is approximately 9.58% with a magnesium recovery rate of 70.66%, the comprehensive copper grade is approximately 2.41% with a copper recovery rate of 38.84%, and the comprehensive cobalt grade is approximately 0.097% with a cobalt recovery rate of 43.31%.

[0053] The yield of copper oxide cobalt concentrate was 41.29%, the calcium grade was 3.83% with a calcium recovery rate of 16.80%, the magnesium grade was 3.49% with a magnesium recovery rate of 21.45%, the copper grade was 0.99% with a copper recovery rate of 13.29%, and the cobalt grade was 0.11% with a cobalt recovery rate of 41.01%.

[0054] The total copper recovery rate of the sulfur concentrate and copper-cobalt oxide concentrate was 61.15%, a decrease of 31.92 percentage points compared to Example 1 (93.07%). Under the experimental conditions of this group, the copper grade and copper recovery rate of the copper-cobalt oxide concentrate in Comparative Example 1 were significantly lower than those in Example 1, indicating that the asynchronous separation-reverse flotation process of the present invention, combined with starch xanthate inhibitors, is beneficial to improving the selective retention of copper oxide minerals and the comprehensive recovery effect of copper resources.

[0055] Example 2

[0056] The oxidized ore raw material used in this embodiment is a copper-cobalt oxide ore with a copper grade of 1.87%, a cobalt grade of 0.27%, a calcium grade of 8.15%, and a magnesium grade of 6.65%. The main useful minerals are malachite, azurite, and chrysocolla. The main cobalt minerals are cobaltite and cobaltite. The main calcium-magnesium carbonate gangue minerals are calcite and dolomite, with quartz and talc also present.

[0057] The flotation process is the same as in Example 1.

[0058] Priority sulfur flotation: The reagent system is adjusted to: 50 g / t of isoamyl xanthate and 15 g / t of No. 2 oil are added during the roughing stage.

[0059] Decalcification and magnesium reverse flotation: In roughing stage 1, add 1500 g / t of starch xanthate inhibitor stock solution (measured as starch xanthate) and 1000 g / t of sodium oleate collector; in roughing stage 2, add 800 g / t of starch xanthate inhibitor stock solution and 800 g / t of sodium oleate collector; in roughing stage 3, add 500 g / t of starch xanthate inhibitor stock solution and 500 g / t of sodium oleate collector.

[0060] The flotation test results were as follows: the sulfur concentrate yield was 19.32%, the calcium grade was 7.01% with a calcium recovery rate of 16.62%, the magnesium grade was 7.24% with a magnesium recovery rate of 21.03%, the copper grade was 2.95% with a copper recovery rate of 30.45%, and the cobalt grade was 0.27% with a cobalt recovery rate of approximately 19.32%.

[0061] The tailings yield is 46.89%, the overall calcium grade is approximately 13.21% with a calcium recovery rate of approximately 76.01%, the overall magnesium grade is approximately 8.85% with a magnesium recovery rate of approximately 62.40%, the overall copper grade is approximately 0.81% with a copper recovery rate of 20.26%, and the overall cobalt grade is approximately 0.123% with a cobalt recovery rate of approximately 21.40%.

[0062] The yield of copper oxide cobalt concentrate was 33.79%, the calcium grade was 1.77% with a calcium recovery rate of 7.34%, the magnesium grade was 3.26% with a magnesium recovery rate of 16.57%, the copper grade was 2.73% with a copper recovery rate of 49.29%, and the cobalt grade was 0.47% with a cobalt recovery rate of approximately 58.83%.

[0063] The total copper recovery rate of the sulfur concentrate and copper-cobalt oxide concentrate was 79.74%, and the total cobalt recovery rate of the sulfur concentrate and copper-cobalt oxide concentrate was approximately 78.15%.

[0064] The copper grade in the copper oxide cobalt concentrate is increased to approximately 1.46 times compared to the feed.

[0065] Comparative Example 2

[0066] This comparative example uses copper-cobalt oxide ore raw materials from the same mine area and batch as in Example 2. The measured copper grade of the ore feed in this experiment was 1.98%, the cobalt grade was 0.26%, the calcium grade was 8.28%, and the magnesium grade was 6.41%. The flotation process was the same as in Example 2, except that the starch xanthate inhibitor stock solution in the decalcification and magnesium reverse flotation process was replaced with the same amount (1500 g / t for rougher 1, 800 g / t for rougher 2, and 500 g / t for rougher 3) of traditional inhibitor water glass.

[0067] The flotation test results are as follows:

[0068] The yield of sulfur concentrate was 20.02%, the grade of calcium was 6.52% with a calcium recovery rate of 15.75%, the grade of magnesium was 6.24% with a magnesium recovery rate of 19.49%, the grade of copper was 2.81% with a copper recovery rate of 28.42%, and the grade of cobalt was 0.26% with a cobalt recovery rate of 20.03%.

[0069] The tailings (X1 and X2 combined) yielded 46.27%, with an overall calcium grade of approximately 11.11% and a calcium recovery rate of approximately 62.03%, an overall magnesium grade of approximately 7.94% and a magnesium recovery rate of approximately 57.30%, an overall copper grade of approximately 1.70% and a copper recovery rate of approximately 39.73%, and an overall cobalt grade of approximately 0.18% and a cobalt recovery rate of approximately 31.94%.

[0070] The yield of copper oxide cobalt concentrate was 33.71%, the calcium grade was 5.46% with a calcium recovery rate of 22.22%, the magnesium grade was 4.41% with a magnesium recovery rate of 23.20%, the copper grade was 1.87% with a copper recovery rate of 31.85%, and the cobalt grade was 0.37% with a cobalt recovery rate of 48.02%.

[0071] The total copper recovery rate of sulfur concentrate and copper-cobalt oxide concentrate was 60.27%, a decrease of 19.47 percentage points compared to 79.74% in Example 2. With the use of water glass as an inhibitor, the copper recovery rate of copper-cobalt oxide concentrate was 31.85%, a decrease of 17.44 percentage points compared to 49.29% in Example 2, indicating that conventional water glass has a weaker selective inhibition ability on copper oxide minerals than starch xanthate.

[0072] From the results of the above examples and comparative examples, it can be seen that: In Example 1, the total copper recovery rate of sulfur concentrate and copper-cobalt oxide concentrate reached 93.07%, of which the copper recovery rate of copper-cobalt oxide concentrate was 43.49%; correspondingly, in Comparative Example 1, the total copper recovery rate of sulfur concentrate and copper-cobalt oxide concentrate was 61.15%, of which the copper recovery rate of copper-cobalt oxide concentrate was 13.29%. In Example 2, the total copper recovery rate of sulfur concentrate and copper-cobalt oxide concentrate was 79.74%, the copper grade of copper-cobalt oxide concentrate was 2.73%, the copper recovery rate was 49.29%, the calcium grade was 1.77%, and the magnesium grade was 3.26%; in Comparative Example 2, the total copper recovery rate of sulfur concentrate and copper-cobalt oxide concentrate was 60.27%, the copper grade of copper-cobalt oxide concentrate was 1.87%, the copper recovery rate was 31.85%, the calcium grade was 5.46%, and the magnesium grade was 4.41%. In Example 2, the copper recovery rate of the copper-cobalt oxide concentrate increased from 31.85% to 49.29% compared to Comparative Example 2, an increase of 17.44 percentage points. These results demonstrate that, under the reagent regime and asynchronous separation-reverse flotation process conditions of this invention, the separation of valuable copper-cobalt minerals from calcium magnesium carbonate gangue can be effectively promoted.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for separating and recovering copper resources from copper oxide ore by reverse flotation, characterized in that: After grinding and slurry preparation, copper oxide ore is desulfurized by flotation reagents including sulfide mineral collectors to obtain sulfur concentrate and desulfurized tailings. The desulfurized tailings are then decalcified and demagnesized by flotation reagents including copper oxide ore depressants and calcium magnesium carbonate mineral collectors. The froth product is calcium magnesium carbonate tailings, and the underflow product is copper oxide concentrate. The copper oxide ore depressant is starch xanthate.

2. The method for separating and recovering copper resources from copper oxide ore by reverse flotation according to claim 1, characterized in that: The starch xanthate has the following molecular structural expression: ； Wherein, [C6H7O2] represents the dehydrated glucose unit, n is the degree of polymerization of the dehydrated glucose unit, OCSSM is the xanthic acid group, x is the degree of substitution of the xanthic acid group, x=0.03~0.07, and M is a hydrogen proton or cation.

3. The method for separating and recovering copper resources from copper oxide ore by reverse flotation according to claim 2, characterized in that: The degree of polymerization n of the dehydrated glucose unit ranges from 100 to 2000.

4. The method for separating and recovering copper resources from copper oxide ore by reverse flotation according to claim 1, characterized in that: The grinding process is controlled to achieve a fineness of 50% to 90% by mass of particles smaller than 200 mesh. The slurry preparation involves adjusting the slurry's mass concentration to 15-45% and its pH to 6.5-8.

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5. A method for separating and recovering copper resources from copper oxide ore by reverse flotation according to any one of claims 1 to 4, characterized in that: The desulfurization flotation includes one roughing process and at least one cleaning process.

6. The method for separating and recovering copper resources from copper oxide ore by reverse flotation according to claim 5, characterized in that: The preliminary selection pharmaceutical regimen is as follows: The dosage of sulfide ore collector is 50-200g per ton of raw ore; The amount of foaming agent used is 10-20g per ton of raw ore; The sulfide mineral collectors include xanthate-based collectors; The foaming agent includes No. 2 oil; The selected selections are blank selections.

7. The method for separating and recovering copper resources from copper oxide ore by reverse flotation according to claim 5, characterized in that: The roughing tailings and cleaning tailings from the desulfurization flotation are combined into desulfurization tailings and then enter the calcium-magnesium carbonate reverse flotation process.

8. A method for separating and recovering copper resources from copper oxide ore by reverse flotation according to claim 1, 2 or 3, characterized in that: The decalcification and magnesium reverse flotation includes at least one roughing stage.

9. A method for separating and recovering copper resources from copper oxide ore by reverse flotation according to claim 8, characterized in that: The preliminary selection pharmaceutical regimen is as follows: For the first roughing process, the dosage of copper oxide ore inhibitor is 500g to 2000g per ton of raw ore, and the dosage of calcium magnesium carbonate mineral collector is 100g to 1000g per ton of raw ore. For subsequent rough selections, the principle of reducing reagents should be followed compared to the first rough selection.

10. A method for separating and recovering copper resources from copper oxide ore by reverse flotation according to claim 9, characterized in that: The calcium magnesium carbonate mineral collector is a fatty acid collector.

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