Method for strengthening leaching of polymetallic ore associated mica type copper oxide ore

Abstract

The invention relates to the technical field of hydrometallurgy, in particular to a method for strengthening leaching of polymetallic ore associated mica type copper oxide ore. The method for strengthening leaching of the polymetallic ore associated mica type copper oxide ore comprises the following steps that the polymetallic ore associated mica type copper oxide ore is sequentially crushed and ground, and ore powder is obtained; leaching the ore powder by adopting an acid leaching agent; wherein the acid leaching agent comprises sulfuric acid, a fluorine ion providing agent and polyvinylpyrrolidone; and after leaching is finished, solid-liquid separation is conducted, and copper-containing leaching liquid and leaching residues are obtained. According to the method, the problem that the wrapped copper in the polymetallic ore associated mica type copper oxide ore is difficult to leach out is effectively solved through the synergistic effect of the fluorine ions and the polyvinylpyrrolidone in the acid leaching environment, efficient recovery of the copper is achieved, the copper leaching rate is high, the leaching efficiency is high, the process is simple, the cost is low, the energy consumption is low, and environment friendliness is achieved.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical technology, and in particular to a method for enhancing the leaching of mica-type copper oxide ores associated with polymetallic ores. Background Technology

[0002] Polymetallic mineral-associated mica-type copper oxide deposits are an important type of copper resource. Their characteristic is that copper is mainly hosted in layered silicate minerals (such as sericite and illite). Phase analysis shows that about 60% to 70% or higher proportion of copper exists in the form of fine-grained dispersions or inclusions in the lattice, interlayer structure or microfractures of gangue minerals.

[0003] In polymetallic mineral-associated mica-type copper oxide deposits, the copper grade is typically economically viable, mostly not less than 0.8%, with some rich ore bodies reaching over 1.5%, and locally even 2% to 3%, indicating significant resource potential. However, because the copper in these deposits is tightly encapsulated by a dense layered silicate structure, conventional acid leaching processes often fail to effectively contact and dissolve the target copper minerals, resulting in extremely low leaching rates and resource waste.

[0004] In existing technologies, sulfuric acid leaching is commonly used to process mica-type copper oxide ores associated with polymetallic minerals. However, under normal temperature and pressure conditions, the activity of hydrogen ions is limited, making it difficult to disrupt the stable structure of mica. Simultaneously, the narrow interlayer spacing of mica minerals severely restricts the mass transfer efficiency between the leaching agent and copper ions, resulting in slow leaching rates and low leaching yields. To improve leaching performance, existing research has proposed enhanced processes such as concentrated sulfuric acid ripening, pre-flotation, sodium chloride roasting, and heated leaching. However, these methods generally suffer from high acid consumption, complex processes, high energy consumption, harsh operating conditions, and difficulty in continuous and stable operation.

[0005] Therefore, there is an urgent need to develop a leaching method for mica-type copper oxide ore associated with polymetallic minerals that can effectively disrupt the mica structure, release encapsulated copper, achieve high leaching rates, rapid leaching, have simple processes, low costs and energy consumption, and be environmentally friendly.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a method for enhancing the leaching of mica-type copper oxide ore associated with polymetallic minerals. By utilizing the synergistic effect of fluoride ions and polyvinylpyrrolidone in an acidic leaching environment, the copper leaching rate of mica-type copper oxide ore associated with polymetallic minerals is significantly improved. At the same time, this method has high leaching efficiency, simple process, low cost, low energy consumption, and is environmentally friendly.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: This invention provides a method for enhancing the leaching of mica-type copper oxide ores associated with polymetallic minerals, comprising the following steps: The polymetallic mineral associated with mica-type copper oxide ore is crushed and ground sequentially to obtain ore powder; The ore powder is leached using an acidic leaching agent; wherein the acidic leaching agent includes sulfuric acid, a fluoride ion donor, and polyvinylpyrrolidone. After the leaching process is completed, solid-liquid separation is performed to obtain copper-containing leachate and leaching residue.

[0009] Furthermore, the mass of polyvinylpyrrolidone in the acidic leaching agent is 0.05% to 0.3% of the mass of the ore powder.

[0010] Furthermore, the molecular weight of the polyvinylpyrrolidone is 10,000 to 60,000.

[0011] Furthermore, the fluoride ion donor includes one or more of ammonium bifluoride, hydrofluoric acid, and sodium fluoride.

[0012] Furthermore, the concentration of fluoride ions in the acidic leaching agent is 0.5~3g / L.

[0013] Furthermore, the pH of the acidic leaching agent is 1.5 to 3.5.

[0014] Furthermore, the solid-liquid ratio of the ore powder and the acidic leaching agent is 1g:2~4mL.

[0015] Furthermore, the leaching temperature is 40~70℃, and the leaching time is 1~3h.

[0016] Furthermore, the copper content in the polymetallic ore associated with mica-type copper oxide ore is ≥0.8wt%.

[0017] Furthermore, the proportion of solid particles with a particle size ≤0.074mm in the ore powder is ≥90wt%.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a method for enhancing the leaching of mica-type copper oxide ore associated with polymetallic minerals. By utilizing the synergistic effect of fluoride ions and polyvinylpyrrolidone in an acidic leaching environment, the method achieves the destruction of mica structure and optimization of mass transfer channels, solving the problem of difficult leaching of encapsulated copper in mica-type copper oxide ore associated with polymetallic minerals. Under mild process conditions, the method achieves high copper recovery and significantly improves the copper leaching rate. Furthermore, the method is characterized by high leaching efficiency, simple process, low cost, low energy consumption, and environmental friendliness. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic flowchart of the method for enhancing the leaching of mica-type copper oxide ore associated with polymetallic minerals according to the present invention. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0022] See Figure 1 In some embodiments of the present invention, a method for enhancing the leaching of mica-type copper oxide ore associated with polymetallic minerals is provided, comprising the following steps: The polymetallic mineral associated with mica-type copper oxide ore is crushed and ground sequentially to obtain ore powder; The ore powder is leached using an acidic leaching agent; wherein the acidic leaching agent includes sulfuric acid and fluoride ions (F... - ) Provider and polyvinylpyrrolidone (PVP); After leaching, solid-liquid separation is performed to obtain copper-containing leachate and leaching residue.

[0023] In polymetallic minerals associated with mica-type copper oxide ores, the copper content is mostly not less than 0.8 wt%, and most of the copper exists in the form of encapsulated mica mineral lattices. For such ores, this invention uses a leaching agent containing sulfuric acid, a fluoride ion donor, and polyvinylpyrrolidone for enhanced leaching. Sulfuric acid provides the acidic environment and hydrogen ions required for leaching, fluoride ions disrupt the mica mineral structure, and polyvinylpyrrolidone expands the interlayer channels of the mineral and optimizes the mass transfer path. By utilizing the synergistic effect of the strongly electronegative fluoride ions and the polyvinylpyrrolidone surfactant in the acidic leaching environment, the mica structure is disrupted and the mass transfer channels are optimized, significantly improving the leaching effect, resulting in a high copper leaching rate and high leaching efficiency, and solving the problem of limited effect of single agents.

[0024] The present invention provides a method for leaching polymetallic minerals associated with enhanced mica-type copper oxide ore, which has a high copper leaching rate, reaching over 85%, which is 25% to 40% higher than that of conventional acid leaching, and the leaching speed is fast.

[0025] The present invention provides a method for enhancing the leaching of mica-type copper oxide ore associated with polymetallic minerals. This method has low energy consumption and cost, requires a leaching temperature significantly lower than that of traditional high-temperature processes, uses less reagent, and has a simple process flow.

[0026] The method for enhancing the leaching of mica-type copper oxide ore associated with polymetallic minerals of the present invention is environmentally friendly, and polyvinylpyrrolidone is a biodegradable, low-toxicity, environmentally friendly surfactant.

[0027] In some embodiments of the invention, the mass of polyvinylpyrrolidone in the acidic leaching agent is 0.05% to 0.3% of the mass of the ore powder; typically, but not limitingly, for example, the mass of polyvinylpyrrolidone in the acidic leaching agent is 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3% of the mass of the ore powder, and any value between any two thereof.

[0028] The dosage of polyvinylpyrrolidone in acidic leaching agents needs to be controlled within a reasonable range. If the dosage is too high, it will not only lead to a significant increase in production costs, but may also cause some unnecessary side reactions due to its excessive concentration in the system, affecting the stability of the leaching process. If the dosage is too low, it will not be able to effectively expand the interlayer channels of minerals and optimize the mass transfer path, making it difficult for the acidic leaching agent to fully contact the effective components inside the minerals, resulting in low leaching efficiency and failure to achieve the ideal leaching effect.

[0029] In some embodiments of the invention, the molecular weight of polyvinylpyrrolidone is 10,000 to 60,000; typically, but not limitingly, for example, the molecular weight of polyvinylpyrrolidone can be 10,000, 20,000, 30,000, 40,000, 50,000, 60,000, and any value between any two of these.

[0030] Molecular weight directly affects the dispersion properties and steric hindrance effect of polyvinylpyrrolidone (PVP). PPVP within the aforementioned molecular weight range has a moderate chain length, offering significant advantages: firstly, the moderate chain length provides excellent dispersion properties, effectively expanding interlayer channels between mineral layers and optimizing mass transfer pathways; secondly, the reasonable steric hindrance effect prevents aggregation of itself or mineral particles, maintaining system stability.

[0031] In some embodiments of the present invention, the fluoride ion donor includes one or more of ammonium bifluoride, hydrofluoric acid, and sodium fluoride.

[0032] The aforementioned types of fluoride ion donors can disrupt the structure of mica minerals, breaking their encapsulation of copper and exposing the encapsulated copper to contact with acid, thereby improving the copper leaching rate.

[0033] In some embodiments of the present invention, the acidic leaching agent contains fluoride ions (F... - The concentration of fluoride ions (F) is 0.5–3 g / L; typically, but not limitingly, for example, in acidic leaching agents... - The concentration of ) can be 0.5 g / L, 1 g / L, 1.5 g / L, 2 g / L, 2.5 g / L, 3 g / L, or any value between any two of these.

[0034] The concentration of fluoride ions in the acidic leaching agent is within the above-mentioned range, ensuring an effective and safe operating window; if the concentration is too low, it will not be sufficient to effectively destroy the mica mineral structure; if the concentration is too high, it will corrode the equipment and increase reagent costs, etc.

[0035] In some embodiments of the invention, the pH of the acidic leaching agent is 1.5 to 3.5; typically, but not limitingly, for example, the pH of the acidic leaching agent can be 1.5, 2, 2.5, 3, 3.5, and any value between any two of these.

[0036] The pH of the acidic leaching agent is adjusted and maintained at 1.5~3.5 by adding sulfuric acid. The initial sulfuric acid concentration is usually 0.05~0.5 mol / L, which is monitored in real time by an online pH meter.

[0037] The pH of the acidic leaching system is controlled between 1.5 and 3.5. This range provides a suitable acidic environment for the synergistic effect of fluoride ions and polyvinylpyrrolidone (PVP): fluoride ions expand the mica mineral channels through interlayer exfoliation, while PVP optimizes mass transfer through steric hindrance. Both need to maintain an active balance under weakly acidic conditions. If the pH is too high, the leaching kinetics of copper slow down (H... + Insufficient concentration), coupled with reduced fluoride ion activity, weakens the interlayer exfoliation effect on mica minerals, leading to a decrease in channel expansion and ultimately a significant reduction in leaching rate; if the pH is too low: strong acid will exacerbate equipment corrosion (such as metal reactor erosion), increasing safety risks; in addition, excessively high acidity will destroy the molecular chain structure of PVP (such as protonation leading to curling), rendering its dispersion and stabilization functions ineffective, and instead inhibiting mass transfer optimization.

[0038] In some embodiments of the present invention, the method for preparing the acidic leaching agent includes the following steps: Add a fluoride ion donor and polyvinylpyrrolidone to the sulfuric acid solution.

[0039] In some embodiments of the present invention, the solid-liquid ratio of ore powder to acidic leaching agent is 1g:2~4mL; typically, but not limitingly, for example, the solid-liquid ratio of ore powder to acidic leaching agent can be 1g:2mL, 1g:3mL, 1g:4mL, and any value between any two thereof.

[0040] A suitable solid-liquid ratio ensures that mineral particles have sufficient space to fully contact, mix, and react with the leaching agent, while also guaranteeing the fluidity of the system, facilitating subsequent operations such as stirring, conveying, and solid-liquid separation.

[0041] In some embodiments of the present invention, the leaching temperature is 40~70°C and the leaching time is 1~3h; typically, but not limitingly, for example, the leaching temperature can be 40°C, 50°C, 60°C, 70°C and any value between any two thereof; the leaching time can be 1h, 2h, 3h and any value between any two thereof.

[0042] This invention enables efficient and rapid leaching of polymetallic mineral-associated mica-type copper oxide ores under mild conditions. Within the aforementioned temperature range, it significantly accelerates chemical reactions and diffusion rates, improves leaching efficiency, and avoids excessive energy consumption, excessive volatilization of acid and fluoride ions, and potential thermal decomposition of polyvinylpyrrolidone caused by excessively high temperatures.

[0043] In some embodiments of the present invention, the copper content in polymetallic mineral-associated mica-type copper oxide ore is ≥0.8wt%; preferably, the copper content in polymetallic mineral-associated mica-type copper oxide ore is 0.8wt%~3.5wt%; more preferably, it is 1.5wt%~3.5wt%; preferably, the polymetallic mineral-associated mica-type copper oxide ore includes gold, silver, tin, copper, lead, and zinc polymetallic-associated mica-type copper oxide ore.

[0044] The method for enhancing the leaching of polymetallic mineral associated mica-type copper oxide ore of the present invention can economically and effectively recover copper from refractory polymetallic mineral associated mica-type copper oxide ore, which is of great significance for the full development and utilization of mineral resources.

[0045] In some embodiments of the present invention, the proportion of solid particles with a particle size ≤0.074mm in the ore powder is ≥90wt%.

[0046] Grinding the ore to a fineness of -0.074% or higher (over 90%) can effectively expose the encapsulated copper minerals, increasing their contact area with the acidic leaching agent and thus improving the leaching effect.

[0047] Example 1 The method for enhancing the leaching of mica-type copper oxide ore associated with polymetallic minerals provided in this embodiment includes the following steps: S1. Take polymetallic mineral associated with mica-type copper oxide ore with a copper content of 2.8wt%. After crushing the polymetallic mineral associated with mica-type copper oxide ore, grind it until solid particles with a particle size ≤0.074mm account for 90wt% of the total solid particles to obtain ore powder. S2. Add ammonium bifluoride and polyvinylpyrrolidone (PVP) with a molecular weight of 40,000 to a sulfuric acid solution (pH=2.0) to obtain an acidic leaching agent; The ore powder and acidic leaching agent were mixed at a solid-liquid ratio of 1g:4mL and leached in a 50℃ water bath for 2 hours with stirring. The acid leaching agent contains 1.5 g / L of fluoride ions and the mass of polyvinylpyrrolidone is 0.15% of the mass of the ore powder. S3. After leaching, the solution is filtered to obtain copper-containing leachate and leaching residue.

[0048] Example 2 The method for enhancing the leaching of mica-type copper oxide ore associated with polymetallic minerals provided in this embodiment includes the following steps: S1. Take polymetallic mineral associated with mica-type copper oxide ore with a copper content of 2.8wt%. After crushing the polymetallic mineral associated with mica-type copper oxide ore, grind it until solid particles with a particle size ≤0.074mm account for 90wt% of the total solid particles to obtain ore powder. S2. Add ammonium bifluoride and polyvinylpyrrolidone (PVP) with a molecular weight of 20,000 to a sulfuric acid solution (pH=2.0) to obtain an acidic leaching agent; The ore powder and acidic leaching agent were mixed at a solid-liquid ratio of 1g:4mL and leached in a 60℃ water bath for 1.5h with stirring. The acid leaching agent contains 1.5 g / L of fluoride ions and the mass of polyvinylpyrrolidone is 0.25% of the mass of the ore powder. S3. After leaching, the solution is filtered to obtain copper-containing leachate and leaching residue.

[0049] Example 3 The method for enhancing the leaching of mica-type copper oxide ore associated with polymetallic minerals provided in this embodiment includes the following steps: S1. Take polymetallic mineral associated with mica-type copper oxide ore with a copper content of 2.8wt%. After crushing the polymetallic mineral associated with mica-type copper oxide ore, grind it until solid particles with a particle size ≤0.074mm account for 90wt% of the total solid particles to obtain ore powder. S2. Add hydrofluoric acid and polyvinylpyrrolidone (PVP) with a molecular weight of 60,000 to a sulfuric acid solution (pH=2.0) to obtain an acidic leaching agent; The ore powder and acidic leaching agent were mixed at a solid-liquid ratio of 1g:4mL and leached by stirring in a 45℃ water bath for 2.5h. The acid leaching agent contains a fluoride ion concentration of 2.0 g / L and a polyvinylpyrrolidone mass of 0.10% of the ore powder mass. S3. After leaching, the solution is filtered to obtain copper-containing leachate and leaching residue.

[0050] Example 4 The method for enhancing the leaching of mica-type copper oxide ore associated with polymetallic minerals provided in this embodiment includes the following steps: S1. Take polymetallic mineral associated with mica-type copper oxide ore with a copper content of 1wt%. After crushing the polymetallic mineral associated with mica-type copper oxide ore, grind it until solid particles with a particle size ≤0.074mm account for 90wt% of the total solid particles to obtain ore powder. S2. Sodium fluoride and polyvinylpyrrolidone (PVP) with a molecular weight of 10,000 are added to a sulfuric acid solution (pH=3.0) to obtain an acidic leaching agent; The ore powder and acidic leaching agent were mixed at a solid-liquid ratio of 1g:2.5mL and leached in a 40℃ water bath for 3 hours with stirring. The acid leaching agent contains a fluoride ion concentration of 3.0 g / L and a polyvinylpyrrolidone mass of 0.30% of the ore powder mass. S3. After leaching, the solution is filtered to obtain copper-containing leachate and leaching residue.

[0051] Comparative Example 1 The method for enhancing the leaching of mica-type copper oxide ore associated with polymetallic minerals provided in this comparative example is the same as in Example 1, except that in step S2, ammonium bifluoride and polyvinylpyrrolidone (PVP) are not added, that is, the acidic leaching agent is a sulfuric acid solution (pH=2.0).

[0052] Comparative Example 2 The method for enhancing the leaching of mica-type copper oxide ore associated with polymetallic minerals provided in this comparative example is the same as in Example 1, except that polyvinylpyrrolidone (PVP) is not added in step S2.

[0053] Comparative Example 3 The method for enhancing the leaching of mica-type copper oxide ore associated with polymetallic minerals provided in this comparative example is the same as in Example 1, except that ammonium bifluoride is not added in step S2.

[0054] Comparative Example 4 The method for enhancing the leaching of mica-type copper oxide ore associated with polymetallic minerals provided in this comparative example is the same as in Example 1, except that in step S2, polyvinylpyrrolidone (PVP) is replaced with hexadecyltrimethylammonium bromide (CTAB).

[0055] Test case The copper content in the copper-containing leaching solutions and leaching residues of Examples 1-4 and Comparative Examples 1-4 was analyzed, and the copper leaching rate was calculated. The results are shown in Table 1.

[0056] Table 1

[0057] As shown in Table 1, the acid leaching agent of the present invention significantly improves the copper leaching rate compared with the use of fluoride ions alone, the use of PVP alone, or conventional acid leaching. Compared with other surfactants, such as CTAB, the use of fluoride ions and polyvinylpyrrolidone has a synergistic effect, which significantly improves the copper leaching rate.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of enhancing leaching of mica type copper oxide ores associated with polymetallic ores, characterized in that, The method comprises the following steps: The polymetallic ore associated with mica type copper oxide ore is crushed and ground in sequence to obtain ore powder; The ore powder is leached by using an acid leaching agent; wherein the acid leaching agent comprises sulfuric acid, a fluorine ion providing agent and polyvinylpyrrolidone; After the leaching is completed, solid-liquid separation is performed to obtain a copper-containing leaching solution and a leaching residue.

2. The process for leaching of a reinforced polymetallic ore associated with mica type copper oxide ore according to claim 1, characterized in that, The mass of the polyvinylpyrrolidone in the acid leaching agent is 0.05% to 0.3% of the mass of the ore powder.

3. The process for leaching of a reinforced polymetallic ore associated with mica type copper oxide ore according to claim 1, characterized in that, The molecular weight of the polyvinylpyrrolidone is 10000 to 60000.

4. The process for leaching of a reinforced polymetallic ore associated with mica type copper oxide ore according to claim 1, characterized in that, The fluorine ion providing agent comprises one or more of ammonium bifluoride, hydrofluoric acid and sodium fluoride.

5. The process for leaching of a reinforced polymetallic ore associated with mica type copper oxide ore according to claim 2, characterized in that, The concentration of fluorine ions in the acid leaching agent is 0.5 to 3 g / L.

6. The process for leaching of a reinforced polymetallic ore associated-mica type copper oxide ore according to claim 5, characterized in that, The pH of the acid leaching agent is 1.5 to 3.

5.

7. The process for leaching of a reinforced polymetallic ore associated-mica type copper oxide ore according to claim 6, characterized in that, The solid-liquid ratio of the ore powder and the acid leaching agent is 1 g: 2 to 4 mL.

8. The process for leaching of a reinforced polymetallic ore associated mica type copper oxide ore as claimed in claim 7 wherein, The temperature of the leaching is 40 to 70 ℃, and the time of the leaching is 1 to 3 h.

9. The process for leaching of a reinforced polymetallic ore associated-mica type copper oxide ore according to claim 8, characterized in that, The copper content in the polymetallic ore associated with mica type copper oxide ore is ≥0.8 wt%.

10. The process for leaching of a reinforced polymetallic ore associated mica type copper oxide ore as claimed in claim 8, wherein, The proportion of solid particles with a particle size ≤0.074 mm in the ore powder is ≥90 wt%.

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