Method for leaching and extracting cobalt and copper in copper sulfide cobalt concentrate

Abstract

The invention provides a method for leaching and extracting cobalt and copper in copper sulfide cobalt concentrate. Comprising the steps that copper-cobalt sulfide concentrate and iron-aluminum slag are mixed and blended, and mixed ore is obtained; the mixed ore and water are mixed and subjected to pulp mixing, and first ore pulp is obtained; pre-acid leaching is conducted on the first ore pulp according to the acid-ore ratio of 150 kg / t-220 kg / t, and second ore pulp is obtained; and carrying out oxygen pressure leaching on the second ore pulp, and carrying out solid-liquid separation to obtain a leachate. The iron-aluminum slag is waste slag which is precipitated in the procedure of removing iron and aluminum through neutralization in the cobalt and copper extraction treatment process of the copper-cobalt sulfide ore. According to the method, the copper-cobalt sulfide concentrate and the iron-aluminum slag are mixed for ore blending, so that the leaching rate of valuable metals such as Co and Cu in the copper-cobalt sulfide concentrate is effectively increased, resource reutilization of the iron-aluminum slag generated in the cobalt and copper extraction treatment process of the copper-cobalt sulfide ore is realized, the environmental pollution is reduced, and the production cost is reduced.

Description

Technical Field

[0001] The invention relates to the field of hydrometallurgy, and in particular to a method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate. Background Art

[0002] In nature, copper and cobalt mostly exist in sulfide ores, arsenide ores and oxide ores in associated forms. Among them, copper-cobalt sulfide ore is one of the common raw materials in the nickel-cobalt hydrometallurgy industry. In industry, the sulfuric acid roasting-leaching process is often used to treat copper-cobalt sulfide concentrates. As for the leaching process, pressure leaching has the advantages of being able to treat complex polymetallic sulfide ores, extracting multiple valuable metals at the same time, high metal extraction rate, and combining leaching and iron removal processes. Cominco in Canada has developed the CESL pressure leaching technology for copper-cobalt concentrates. The leachate is sent to the extraction-electrodeposition system to produce pure copper and pure cobalt.

[0003] The extraction processes of valuable metals such as Cu and Co in copper-cobalt sulfide concentrate mainly include pyrometallurgy, wet acid leaching, wet acid leaching + ammonia extraction, wet acid leaching + carbonate reverse flotation, and wet acid leaching + oxygen pressure leaching. Among them, the pyrometallurgy process has been basically eliminated due to its high energy consumption, heavy environmental pollution, and strong corrosion to equipment. The ammonia extraction process has also been basically eliminated due to the high price of ammonia extractants. Although the wet acid leaching + ammonia extraction process can recover Cu and Co from copper-cobalt sulfide concentrate, the ammonia extractant is difficult to recover, the ammonia extractant consumption is large, and the ammonia extractant is prone to generate by-products with a foul odor during the recovery process. The wet acid leaching + carbonate reverse flotation process has a high consumption of reagents for carbonate reverse flotation, and a large amount of medium and low-quality flotation foam will be generated during the reverse flotation process. The flotation foam will cause serious equipment corrosion and unstable production. The wet acid leaching + oxygen pressure leaching process has the advantages of simple operation, short process, low equipment corrosion and high product purity. However, oxygen pressure leaching has a low degree of oxidation of S, Fe and Al in the copper-cobalt sulfide concentrate, and the amount of leaching slag after oxygen pressure leaching is large, the cost of leaching slag treatment is high, and the treatment is difficult, which is not conducive to the recovery of valuable metals in the copper-cobalt sulfide concentrate.

[0004] That is to say, the oxygen pressure leaching method for copper-cobalt sulfide concentrate still has the problem of low metal element leaching recovery rate and complicated process and poor economy. In view of this, CN 112760480 A provides a method for improving the oxygen pressure leaching efficiency of copper-cobalt sulfide concentrate, which uses low-sulfur materials such as quartz sand as a regulator of sulfur content in copper-cobalt sulfide concentrate, enhances the stability of the leaching process of metal elements such as copper and cobalt, facilitates the control of temperature in actual production, and effectively improves the oxygen pressure leaching efficiency of copper-cobalt sulfide concentrate. CN 113789441 A provides a combined leaching process of cobalt-sulfur concentrate and cobalt hydroxide ore, which oxidizes sulfur ions into sulfate ions and ferrous ions into iron ions by combining cobalt-sulfur concentrate and cobalt hydroxide ore under high pressure, and leaches cobalt hydroxide using the generated hydrogen ions, and also leaches cobalt, copper and nickel in the cobalt-sulfur concentrate into the solution. However, the above two solutions only improve the oxygen pressure leaching efficiency of Co and Cu elements, but the recovery of other elements such as Fe and Al is poor. At the same time, the recovery rate of each element still has room for improvement, and the back-end process is very consuming.

[0005] At the same time, the copper-cobalt ore processing process will produce iron-aluminum precipitate slag, which contains a small amount of Ni and Co. If Ni and Co are to be recovered, secondary neutralization precipitation is required in the process, which consumes a large amount of neutralizer and has poor economic efficiency.

[0006] Based on this, how to reintroduce the iron-aluminum precipitate slag produced during the treatment of copper-cobalt sulfide ore into the leaching and extraction method of copper-cobalt sulfide concentrate to achieve its secondary utilization, and at the same time improve the leaching rate of copper and cobalt in the copper-cobalt sulfide concentrate to achieve better recovery effect, is one of the technical problems that need to be solved in this field. Summary of the invention

[0007] The main purpose of the present invention is to provide a method for leaching and extracting cobalt and copper in copper-cobalt sulfide concentrate, so as to solve the problem that the prior art cannot achieve the leaching and extraction of cobalt and copper elements in copper-cobalt sulfide concentrate with high recovery rate and high selectivity, and it is also difficult to effectively recycle the iron-aluminum precipitate slag generated in the process of cobalt sulfide ore treatment.

[0008] In order to achieve the above-mentioned object, the present invention provides a method for leaching and extracting cobalt and copper in copper-cobalt sulfide concentrate, comprising: step S1, mixing the copper-cobalt sulfide concentrate with ferroaluminum slag to obtain a mixed ore; in the mixed ore, the weight ratio of the copper-cobalt sulfide concentrate to the ferroaluminum slag is (2.5-8):1; step S2, mixing the mixed ore with water to prepare a slurry to obtain a first slurry; step S3, pre-acid leaching the first slurry according to an acid-ore ratio of 150kg / t-220kg / t to obtain a second slurry; step S4, performing oxygen pressure leaching on the second slurry at an oxygen partial pressure of 0.3MPa-1.2MPa, a stirring speed of 600r / min-900r / min, and a time of 0.8h-3.0h, and obtaining a leachate through solid-liquid separation; the ferroaluminum slag is a waste slag material precipitated in the process of neutralizing and removing iron and aluminum in the process of extracting cobalt and copper from the copper-cobalt sulfide ore.

[0009] Furthermore, the ferroaluminum slag includes, by weight, 0.1 to 0.5 parts of Cu, 0.1 to 0.6 parts of Co, 2.5 to 5.0 parts of Fe and 5.0 to 8.0 parts of Al.

[0010] Furthermore, the copper-cobalt sulfide concentrate includes, by weight, 15.0 to 25.0 parts of Cu, 8.0 to 15.0 parts of Co, 1.0 to 3.0 parts of Fe and 1.0 to 2.5 parts of Al.

[0011] Furthermore, based on the total weight of the copper-cobalt sulfide concentrate as 100%, the copper-cobalt sulfide concentrate with a particle size of 200 mesh accounts for 97% to 99%; and / or, based on the total weight of the iron-aluminum slag as 100%, the iron-aluminum slag with a particle size of 150 mesh accounts for 98% to 99%.

[0012] Furthermore, the D50 of the copper-cobalt sulfide concentrate is 100-150 mesh; and / or the D50 of the iron-aluminum slag is 80-120 mesh.

[0013] Furthermore, in the mixed ore, the weight ratio of the copper-cobalt sulfide concentrate to the iron-aluminum slag is (5~8):1.

[0014] Furthermore, in step S2, the liquid-to-solid ratio of the mixed slurry is (4-12):1, and the mixed slurry is carried out at a stirring speed of 300 r / min-800 r / min.

[0015] Furthermore, in step S3, an inorganic acid solution and / or an organic acid solution with a mass concentration of 50% to 98% is used as the acid solution for pre-acid leaching.

[0016] Furthermore, in step S3, the pre-acid leaching temperature is 25°C to 80°C, and the time is 60min to 120min.

[0017] Furthermore, in step S4, the temperature of oxygen pressure leaching is 160°C to 220°C; preferably, the pH value of the leaching solution is 1.0 to 2.5.

[0018] By applying the technical solution of the present invention, by mixing the copper-cobalt sulfide concentrate with the ferroaluminum slag, not only the leaching rate of Co and Cu valuable metals in the copper-cobalt sulfide concentrate is effectively improved, but also the resource recycling of the ferroaluminum slag generated in the process of extracting cobalt and copper from the copper-cobalt sulfide ore is realized, thereby reducing environmental pollution and lowering production costs. DETAILED DESCRIPTION

[0019] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0020] As described in the background art, the prior art is unable to improve the leaching rate of cobalt and copper in the copper-cobalt sulfide concentrate while reducing the recovery rate of iron and aluminum therein. In other words, there is a problem that the leaching and extraction of cobalt and copper elements in the copper-cobalt sulfide concentrate cannot be achieved with high selectivity. At the same time, the prior art also has the problem of difficulty in effectively recycling the iron and aluminum precipitate slag generated during the treatment of cobalt sulfide ore.

[0021] In order to solve the above technical problems, the present invention provides a method for leaching and extracting cobalt and copper in copper-cobalt sulfide concentrate, comprising: step S1, mixing the copper-cobalt sulfide concentrate with ferroaluminum slag to obtain a mixed ore; in the mixed ore, the weight ratio of the copper-cobalt sulfide concentrate to the ferroaluminum slag is (2.5-8):1; step S2, mixing the mixed ore with water to prepare a slurry to obtain a first slurry; step S3, pre-acid leaching the first slurry according to an acid-ore ratio of 150kg / t-220kg / t to obtain a second slurry; step S4, performing oxygen pressure leaching on the second slurry at an oxygen partial pressure of 0.3MPa-1.2MPa, a stirring speed of 600r / min-900r / min, and a time of 0.8h-3.0h, and obtaining a leachate through solid-liquid separation; the ferroaluminum slag is a waste slag material precipitated in the process of neutralizing and removing iron and aluminum in the process of extracting cobalt and copper from the copper-cobalt sulfide ore.

[0022] The present invention introduces the iron-aluminum slag produced by the process of removing iron and aluminum in the process of extracting cobalt and copper from the copper-cobalt sulfide ore into the process of extracting cobalt and copper from the copper-cobalt sulfide concentrate, and uses it as an inhibitor to inhibit aluminum leaching in the process of leaching the copper-cobalt sulfide concentrate, thereby achieving efficient inhibition of the leaching of impurity elements such as iron and aluminum in the copper-cobalt sulfide concentrate, achieving efficient leaching of valuable metals such as copper and cobalt, and also achieving effective recovery of a small amount of copper and cobalt in the iron-aluminum slag. Specifically, the weight ratio of the copper-cobalt sulfide concentrate to the iron-aluminum slag is strictly limited to (2.5~8):1, and the two are mixed according to this ratio. Within this weight ratio range, the leaching of Fe and Al can be more effectively inhibited, and Ni and Co can be efficiently recovered. At the same time, under this weight ratio, the efficiency of oxygen pressure leaching can be significantly optimized, the leaching rate of copper and cobalt can be improved, while ensuring a lower leaching rate of iron and aluminum, and achieving more effective separation and recovery of Ni and Co metals. At the same time, the acid-ore ratio can control the pH value during the reaction process and maintain it under the optimal acidic conditions, thereby ensuring efficient leaching of metals and inhibiting the leaching of other impurity elements (i.e., iron and aluminum) that are not desired to be dissolved. More importantly, since the acid-ore ratio in the pre-acid leaching process directly affects the amount of sulfuric acid used and the generation of sulfate ions, the acid-ore ratio range of 150 kg / t~220 kg / t can achieve a good balance of sulfate ions in the second pulp, avoiding the generation of too many sulfate ions and causing excess sulfuric acid in the solution, which in turn affects the treatment of the leachate and the recovery of Ni and Co metals. Finally, strictly controlling the oxygen pressure leaching conditions for the above-mentioned special pulp system as above helps to provide sufficient oxidation leaching power, so that the metal sulfides in the copper-cobalt sulfide concentrate can be more efficiently oxidized, dissolved and leached, and the difficulty of oxidation of different metals in the leaching process can be adjusted, thereby suppressing the leaching of impurities such as iron and aluminum while increasing the copper and cobalt leaching rate, and improving the purity, recovery efficiency and selectivity of the metal.

[0023] It should be noted that the above steps and corresponding conditions in the leaching recovery method provided by the present invention cooperate with each other as an overall technical solution, that is, forming a complete technical route of "mixing ore at a specific weight ratio → slurry preparation → pre-acid leaching at a specific acid-ore ratio → oxygen pressure leaching under specific conditions". In addition to the design of the process flow, it also includes the optimization of parameters in each process stage. For the leaching of cobalt and copper in sulfide copper-cobalt concentrate, compared with the conventional method including pre-acid leaching + oxygen pressure leaching process commonly used in the field, it can more effectively improve the leaching rate of Ni and Co, and significantly inhibit the leaching of Fe and Al. That is to say, the above steps in the leaching method provided by the present invention, in addition to the advantages they have themselves, are more importantly able to cooperate with each other, that is, as an overall solution, to achieve efficient and highly selective leaching and extraction of cobalt and copper in sulfide copper-cobalt concentrate.

[0024] In general, the above method provided by the present invention not only has the advantages of high copper and cobalt leaching rate, low iron and aluminum leaching rate, good sulfate balance in the leaching process, and no obvious excess sulfuric acid, but also can realize the secondary recycling of iron and aluminum slag, thus having excellent environmental and economic benefits.

[0025] In several typical embodiments, it is preferred to use an acid-ore ratio of 200 kg / t to 220 kg / t during the pre-acid leaching process in order to provide a sufficiently acidic environment, thereby more effectively promoting the dissolution of metal sulfides in the copper-cobalt sulfide concentrate and significantly improving the leaching rates of copper and cobalt.

[0026] With respect to the raw material of ferroaluminum slag, the inventors have preferably determined, after a large number of experiments, that the ferroaluminum slag includes 0.1-0.5 parts of Cu, 0.1-0.6 parts of Co, 2.5-5.0 parts of Fe and 5.0-8.0 parts of Al by weight. The ferroaluminum slag with this composition has a high content of Fe and Al. At the same time, by matching the conditions of the above-mentioned pre-acid leaching and oxygen pressure leaching processes (such as oxygen partial pressure, stirring speed, leaching time, etc.), more Fe and Al can be retained in the leached slag instead of leaching into the solution, that is, a good inhibitory effect is played, thereby more effectively optimizing the metal content of the leachate and improving the efficiency of subsequent metal separation and recovery.

[0027] Specifically, the iron-aluminum slag with the above-mentioned composition can be obtained by acid leaching, alkali leaching and oxidation leaching of copper-cobalt ore, copper-cobalt concentrate and other iron-aluminum-containing minerals to generate insoluble iron sulfate (Fe2(SO4)3), aluminum sulfate (Al2(SO4)3) and other substances, which remain in the oxygen pressure leaching slag in an insoluble form, thereby forming iron-aluminum slag. In this process, a small amount of Fe / Al will enter the leachate, and then the iron and aluminum ions can be precipitated into the slag through neutralization precipitation (the pH of the solution is adjusted to 4.5~5.2), which can also form iron-aluminum slag.

[0028] As for the main processing object, the copper-cobalt sulfide concentrate preferably includes 15.0-25.0 parts of Cu, 8.0-15.0 parts of Co, 1.0-3.0 parts of Fe and 1.0-2.5 parts of Al in terms of weight, so as to better adapt to the above-mentioned leaching method and achieve a higher cobalt-copper leaching rate.

[0029] Further, based on the total weight of the copper-cobalt sulfide concentrate as 100%, the proportion of the copper-cobalt sulfide concentrate with a particle size of 200 mesh is 97% to 99%; and / or, based on the total weight of the iron-aluminum slag as 100%, the proportion of the iron-aluminum slag with a particle size of 150 mesh is 98% to 99%. The particle size range of the copper-cobalt sulfide concentrate and the iron-aluminum slag material selected above can further increase the contact area between the two, making the mixed ore obtained by mixing the ore more uniform, and also making the pre-acid leaching and oxygen pressure leaching more sufficient, thereby increasing the leaching rate of cobalt and copper elements. In several typical embodiments, the D50 of the copper-cobalt sulfide concentrate is preferably 100 mesh to 150 mesh; and / or, the D50 of the iron-aluminum slag is 80 mesh to 120 mesh, which helps to more effectively improve the uniformity of the obtained mixed ore, so as to improve the stability and efficiency of the leaching process, thereby increasing the leaching rate of cobalt and copper elements. More importantly, the above two particle size ranges can more significantly affect the leaching selectivity of the metal. Among them, the smaller particle size of the copper-cobalt sulfide concentrate can increase its surface area, increase the dissolution rate, promote the dissolution of a small amount of Cu and Co, and improve the metal recovery rate. The larger particle size of the ferroaluminum slag is conducive to inhibiting the leaching of Fe and Al. At the same time, the above-mentioned particle size difference can promote good contact and mixing between the copper-cobalt sulfide concentrate and the ferroaluminum slag, thereby improving the efficiency and rate of the metal leaching reaction.

[0030] In order to better adapt to the above-mentioned particle size relationship, the inventors further optimized the weight of the two through a large number of experiments, so that the weight ratio of copper-cobalt sulfide concentrate to iron-aluminum slag in the mixed ore is (5-8):1, thereby obtaining a better leaching and extraction effect, and more effectively improving the leaching rate of Cu and Co while suppressing the leaching of Fe and Al.

[0031] After the mixed ore is obtained, preferably in step S2, the liquid-to-solid ratio of the mixed slurry is (4-12):1, and the mixed slurry is performed at a stirring speed of 300r / min-800r / min. The above-mentioned preferred slurrying conditions can obtain a first slurry with higher uniformity, dispersibility and fluidity, thereby improving the efficiency of the subsequent pre-acid leaching and oxygen pressure leaching processes, and ultimately improving the leaching rates of Co and Cu.

[0032] In order to adapt to the above-mentioned pre-acid leaching conditions, achieve pre-acid leaching and oxygen pressure leaching with higher efficiency, and reduce the introduction of impurities, it is preferred that in step S3, an inorganic acid solution and / or an organic acid solution with a mass concentration of 50% to 98% is used as the acid solution used for pre-acid leaching; the inorganic acid solution is preferably a sulfuric acid solution. Compared with other types of acid solutions commonly used in the art, sulfuric acid, i.e., an inorganic acid solution, of the above-mentioned mass concentration is a strong acid that can efficiently dissolve copper sulfide (such as CuS, Cu2S) and cobalt sulfide (such as CoS, CoS2), thereby achieving a high leaching rate. At the same time, the by-products (such as sulfates) produced during sulfuric acid leaching can be further processed and utilized to reduce waste emissions.

[0033] In several typical embodiments, in the preferred step S3, an organic acid solution with a molar concentration of 0.1mol / L~0.5mol / L is used as the acid solution for pre-acid leaching, and the organic acid solution is selected from one or more of oxalic acid, citric acid and tartaric acid. Compared with the strong acid solution of sulfuric acid, the above-mentioned organic acid solution has higher selectivity, can form a stable complex with copper and cobalt, and reduce the co-leaching of impurities, so that copper and cobalt can be extracted more effectively, and it is particularly suitable for treating such low-grade and complex ores treated by the present invention. At the same time, the impact of organic acids on the environment is also small, and the environmental protection is excellent. And, the more preferably used organic acid molar concentration is 0.48mol / L~0.5mol / L, so as to further improve the leaching rate of each element on the basis of improving selectivity and achieve a better leaching and extraction effect.

[0034] Further, in step S3, in order to better balance the reaction efficiency in the pre-acid leaching, and also to make the metal sulfide react more fully with the acid and improve the leaching rate, the pre-acid leaching temperature is preferably 25°C~80°C, and the time is 60min~120min. It is preferred that the pre-acid leaching is carried out at a stirring speed of 300r / min~700r / min, which can promote the uniform mixing of the slurry and accelerate the contact between the reactants, thereby further improving the reaction rate and leaching efficiency. It is more preferred that step S4 is carried out when the pH value of the second slurry reaches 0.8~2. At this time, the pH value range of 0.8~2 can provide a strong acidic environment, promote the dissolution of metal sulfides, and inhibit the dissolution of certain impurity elements, such as Fe and Al. It is preferred that when the pH value reaches this range, the pre-acid leaching process is considered to be basically completed, and at this time, the oxygen pressure leaching step is entered, which can promote the efficient leaching of cobalt and copper metals, while reducing the dissolution of impurities, and more significantly improve its leaching rate.

[0035] In several typical embodiments, in step S4, the temperature of oxygen pressure leaching is 160°C to 220°C. In this temperature range, the oxidation reaction rate can be increased, the dissolution of metal sulfides such as copper and cobalt can be accelerated, and the leaching efficiency can be improved. At the same time, this temperature range is conducive to the deep oxidation of metal sulfides, converting the insoluble sulfides into a more soluble form, thereby more effectively improving the leaching rate of the metal. In particular, the temperature can more effectively control the sulfate balance in the reaction system, optimize the amount of sulfate generated, maintain the chemical balance of the leachate, and facilitate subsequent metal separation, that is, to achieve the leaching of valuable metals in the copper-cobalt sulfide concentrate with higher selectivity. In several more typical embodiments, the pH value of the leachate is 1 to 2.5. In the leachate within this acidity range, the leaching rate of metals such as copper and cobalt can be optimized, while the dissolution of impurities such as Fe and Al is suppressed, ultimately achieving the improvement of the purity of the leachate and the high selectivity recovery of the metal.

[0036] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0037] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0038] Example 1

[0039] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0040] Copper-cobalt sulfide concentrate and iron-aluminum slag are provided, and the composition and content of the two are shown in Table 1. Among them, the copper-cobalt sulfide concentrate is obtained by flotation enrichment of copper-cobalt sulfide ore, and the iron-aluminum slag is obtained by neutralization and precipitation of the leaching solution of the copper-cobalt sulfide concentrate.

[0041] Among the processed copper-cobalt sulfide concentrate, the proportion of copper-cobalt sulfide concentrate with a particle size of less than 200 meshes is 98%; among the processed iron-aluminum slag, the proportion of iron-aluminum slag with a particle size of less than 150 meshes is 99%. In addition, the D50 of the processed copper-cobalt sulfide concentrate is 100 mesh, and the D50 of the processed iron-aluminum slag is 100 mesh.

[0042] Table 1

[0043]

[0044] (1) 100 g of copper-cobalt sulfide concentrate and 18 g of ferroaluminum slag are mixed to obtain a mixed ore; wherein the weight ratio of the copper-cobalt sulfide concentrate to the ferroaluminum slag is 5.56:1;

[0045] (2) controlling the liquid-solid ratio to be 8:1, and preparing a slurry by mixing the mixed ore and water at a stirring speed of 500 r / min to obtain a first slurry;

[0046] (3) using a sulfuric acid solution with a mass concentration of 98% as the acid solution, controlling the acid-ore ratio to be 200 kg / t, and pre-acid leaching the first slurry at an operating temperature of 30° C. and a stirring speed of 500 r / min for 60 min until the pH value thereof reaches 0.9, thereby obtaining a second slurry;

[0047] (4) The ore pulp after pre-acid leaching, i.e., the second ore pulp, is transferred to an oxygen pressure leaching reactor, oxygen is introduced, and oxygen pressure leaching is carried out at 200°C, an oxygen partial pressure of 0.4 MPa, and a stirring speed of 800 r / min for 1 hour. After solid-liquid separation, a leachate with a pH of 1.8 is obtained, which contains Co, Cu, Fe, and Al elements.

[0048] Example 2

[0049] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0050] The copper-cobalt sulfide concentrate and iron-aluminum slag used in Example 1 are used as processing raw materials.

[0051] (1) 100 g of copper-cobalt sulfide concentrate and 34 g of ferroaluminum slag are mixed to obtain a mixed ore; wherein the weight ratio of the copper-cobalt sulfide concentrate to the ferroaluminum slag is 2.94:1;

[0052] (2) controlling the liquid-solid ratio to be 8:1, and preparing a slurry by mixing the mixed ore and water at a stirring speed of 300 r / min to obtain a first slurry;

[0053] (3) using a sulfuric acid solution with a mass concentration of 98% as the acid solution, controlling the acid-ore ratio to be 200 kg / t, and pre-acid leaching the first slurry at an operating temperature of 30° C. and a stirring speed of 500 r / min for 60 min until the pH value thereof reaches 0.9, thereby obtaining a second slurry;

[0054] (4) The ore pulp after pre-acid leaching, i.e., the second ore pulp, is transferred to an oxygen pressure leaching reactor, oxygen is introduced, and oxygen pressure leaching is carried out at 200°C, an oxygen partial pressure of 0.4 MPa, and a stirring speed of 800 r / min for 1 hour. After solid-liquid separation, a leachate with a pH of 1.8 is obtained, which contains Co, Cu, Fe, and Al elements.

[0055] Example 3

[0056] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0057] The copper-cobalt sulfide concentrate and iron-aluminum slag used in Example 1 are used as processing raw materials.

[0058] (1) 100 g of copper-cobalt sulfide concentrate and 12.5 g of ferroaluminum slag are mixed to obtain a mixed ore; wherein the weight ratio of the copper-cobalt sulfide concentrate to the ferroaluminum slag is 8.00:1;

[0059] (2) controlling the liquid-solid ratio to be 8:1, and preparing a slurry by mixing the mixed ore and water at a stirring speed of 800 r / min to obtain a first slurry;

[0060] (3) using a sulfuric acid solution with a mass concentration of 98% as the acid solution, controlling the acid-ore ratio to be 200 kg / t, and pre-acid leaching the first slurry at an operating temperature of 30° C. and a stirring speed of 500 r / min for 60 min until the pH value thereof reaches 0.9, thereby obtaining a second slurry;

[0061] (4) The ore pulp after pre-acid leaching, i.e., the second ore pulp, is transferred to an oxygen pressure leaching reactor, oxygen is introduced, and oxygen pressure leaching is carried out at 200°C, an oxygen partial pressure of 0.4 MPa, and a stirring speed of 800 r / min for 1 hour. After solid-liquid separation, a leachate with a pH of 1.8 is obtained, which contains Co, Cu, Fe, and Al elements.

[0062] Example 4

[0063] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0064] The only difference between this embodiment and embodiment 1 is that the liquid-to-solid ratio in step (2) is changed to 4:1.

[0065] Example 5

[0066] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0067] The only difference between this embodiment and embodiment 1 is that the acid-ore ratio in step (3) is changed to 150 kg / t, and the pH value of the obtained second slurry is changed to 2.

[0068] Example 6

[0069] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0070] The only difference between this embodiment and embodiment 1 is that the acid-ore ratio in step (3) is changed to 220 kg / t, and the pH value of the obtained second slurry is changed to 0.8.

[0071] Example 7

[0072] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0073] The only difference between this embodiment and embodiment 1 is that the pre-acid leaching time in step (3) is changed to 120 minutes.

[0074] Example 8

[0075] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0076] The only difference between this embodiment and embodiment 1 is that the stirring speed in step (4) is changed to 900 r / min.

[0077] Example 9

[0078] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0079] The only difference between this embodiment and embodiment 1 is that the oxygen partial pressure in step (4) is changed to 1.2 MPa.

[0080] Example 10

[0081] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0082] The only difference between this embodiment and embodiment 1 is that the oxygen pressure leaching time in step (4) is changed to 0.8 h.

[0083] Embodiment 11

[0084] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0085] The only difference between this embodiment and embodiment 1 is that the oxygen pressure leaching time in step (4) is changed to 3.0 h.

[0086] Example 12

[0087] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0088] The only difference between this embodiment and embodiment 1 is that the D50 of the processed copper-cobalt sulfide concentrate is changed to 80 mesh, and the D50 of the processed iron-aluminum slag is changed to 50 mesh.

[0089] Embodiment 13

[0090] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0091] The only difference between this embodiment and embodiment 1 is that the D50 of the processed copper-cobalt sulfide concentrate is changed to 200 mesh, and the D50 of the processed iron-aluminum slag is changed to 250 mesh.

[0092] Embodiment 14

[0093] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0094] The only difference between this embodiment and embodiment 1 is that the stirring speed in step (2) is changed to 900 r / min.

[0095] Embodiment 15

[0096] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0097] The only difference between this embodiment and embodiment 1 is that the stirring speed in step (2) is changed to 200 r / min.

[0098] Example 16

[0099] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0100] The only difference between this embodiment and embodiment 1 is that the temperature of the pre-acid leaching in step (3) is changed to 20°C, the stirring speed is changed to 800 r / min, the time is changed to 140 min, and the pH value of the obtained second slurry is changed to 0.6.

[0101] Embodiment 17

[0102] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0103] The only difference between this embodiment and embodiment 1 is that the temperature of the pre-acid leaching in step (3) is changed to 90°C, the stirring speed is changed to 200 r / min, the time is changed to 40 min, and the pH value of the obtained second slurry is changed to 2.5.

[0104] Embodiment 18

[0105] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0106] The only difference between this embodiment and embodiment 1 is that the temperature of oxygen pressure leaching in step (4) is changed to 150°C.

[0107] Embodiment 19

[0108] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0109] The only difference between this embodiment and embodiment 1 is that the temperature of oxygen pressure leaching in step (4) is changed to 250°C.

[0110] Embodiment 20

[0111] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0112] The only difference between this embodiment and embodiment 1 is that the sulfuric acid solution used for pre-acid leaching in step (3) is replaced by oxalic acid with a molar concentration of 0.5 mol / L.

[0113] Comparative Example 1

[0114] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0115] The only difference between this comparative example and Example 1 is that no ferroaluminum slag is added, but the copper-cobalt sulfide concentrate is directly used as the mixed ore and the subsequent steps are carried out.

[0116] Comparative Example 2

[0117] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0118] The difference between this comparative example and Example 1 is that the amount of ferroaluminum slag in step (1) is changed to 50 g, and the weight ratio of the copper-cobalt sulfide concentrate to the ferroaluminum slag is 2:1.

[0119] Comparative Example 3

[0120] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0121] The difference between this comparative example and Example 1 is that the amount of ferroaluminum slag in step (1) is changed to 10 g, and the weight ratio of the copper-cobalt sulfide concentrate to the ferroaluminum slag is 10:1.

[0122] Comparative Example 4

[0123] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0124] The only difference between this comparative example and Example 1 is that the acid-ore ratio in step (3) is changed to 120 kg / t, and the pH value of the obtained second slurry is changed to 2.5.

[0125] Comparative Example 5

[0126] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0127] The only difference between this comparative example and Example 1 is that the stirring speed in step (4) is changed to 400 r / min.

[0128] Comparative Example 6

[0129] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0130] The only difference between this comparative example and Example 1 is that the oxygen partial pressure in step (4) is changed to 0.2 MPa.

[0131] Comparative Example 7

[0132] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0133] The only difference between this comparative example and Example 1 is that the oxygen partial pressure in step (4) is changed to 1.5 MPa.

[0134] Comparative Example 8

[0135] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0136] The only difference between this comparative example and Example 1 is that the oxygen pressure leaching time in step (4) is changed to 0.5 h.

[0137] Comparative Example 9

[0138] A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate:

[0139] The only difference between this comparative example and Example 1 is that an equal weight of aluminum sulfate is used to replace the ferroaluminum slag.

[0140] The leaching rates of Co, Cu, Fe and Al elements in the leaching solutions obtained in the embodiments and comparative examples are shown in Table 2.

[0141] Table 2

[0142]

[0143] From the above description, it can be seen that the above-mentioned embodiment of the present invention realizes the effective utilization of the iron-aluminum precipitate slag produced in the copper-cobalt sulfide ore processing process, introduces it into the cobalt and copper leaching process in the copper-cobalt sulfide concentrate, and realizes a higher leaching rate of cobalt and copper elements.

[0144] Specifically, the iron-aluminum slag produced in the neutralization precipitation process is used as an inhibitor to inhibit the leaching of iron and aluminum in the leaching process of copper-cobalt sulfide concentrate. The concentrate and the iron-aluminum slag with a ratio of (2.5~8):1 are used to extract valuable metals such as copper and cobalt through a pre-leaching-oxygen pressure leaching process. By controlling the particle size and ratio of the concentrate and the iron-aluminum slag, and controlling the acid-ore ratio, liquid-solid ratio, oxygen partial pressure, leaching temperature and other conditions of pre-leaching and oxygen pressure leaching, the leaching rate of copper and cobalt is increased, and the leaching rate of iron and aluminum is reduced.

[0145] Among them, regarding Example 14 and Example 15, the reduction of the stirring speed will have a certain impact on the degree of reaction and the leaching rate. When the stirring speed is increased, the leaching rate of copper and cobalt increases accordingly, but the leaching rate of impurities such as Fe will also increase accordingly. Therefore, the mixing and slurrying in the preferred step S2 of the present invention is carried out at a stirring speed of 300r / min~800r / min, so as to match the components of the processed slurry and obtain a first slurry with higher uniformity, dispersibility and fluidity, thereby promoting the improvement of the efficiency of the subsequent pre-acid leaching and oxygen pressure leaching processes, and ultimately improving the leaching rates of Co and Cu under the condition of reducing the impurity leaching rate.

[0146] And, in Comparative Example 7, the oxygen partial pressure increases, and the element leaching rate increases accordingly. However, under this condition, copper is wrapped by iron, so its leaching rate is significantly reduced, and the overall effect is poor.

[0147] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those described herein, for example.

[0148] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate, characterized in that: include: Step S1, mixing the copper-cobalt sulfide concentrate with the iron-aluminum slag to obtain a mixed ore; in the mixed ore, the weight ratio of the copper-cobalt sulfide concentrate to the iron-aluminum slag is (2.5-8):1; Step S2, mixing the mixed ore with water to obtain a first ore slurry; Step S3, pre-acid leaching the first slurry at an acid-ore ratio of 150 kg / t to 220 kg / t to obtain a second slurry; Step S4, subjecting the second slurry to oxygen pressure leaching at an oxygen partial pressure of 0.3 MPa to 1.2 MPa, a stirring speed of 600 r / min to 900 r / min, and a time of 0.8 h to 3.0 h, and obtaining a leachate by solid-liquid separation; The iron-aluminum slag is waste slag precipitated from the process of neutralizing and removing iron and aluminum during the process of extracting cobalt and copper from sulfide copper-cobalt ore.

2. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to claim 1, characterized in that: In parts by weight, the ferroaluminum slag includes 0.1 to 0.5 parts of Cu, 0.1 to 0.6 parts of Co, 2.5 to 5.0 parts of Fe and 5.0 to 8.0 parts of Al.

3. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to claim 2, characterized in that: In parts by weight, the copper-cobalt sulfide concentrate includes 15.0-25.0 parts of Cu, 8.0-15.0 parts of Co, 1.0-3.0 parts of Fe and 1.0-2.5 parts of Al.

4. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to any one of claims 1 to 3, characterized in that: Based on the total weight of the copper-cobalt sulfide concentrate as 100%, the copper-cobalt sulfide concentrate having a particle size of less than 200 mesh accounts for 97% to 99%; and / or, Taking the total weight of the iron-aluminum slag as 100%, the iron-aluminum slag with a particle size less than 150 mesh accounts for 98% to 99%.

5. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to any one of claims 1 to 3, characterized in that: The D50 of the copper-cobalt sulfide concentrate is 100-150 mesh; and / or the D50 of the iron-aluminum slag is 80-20 mesh.

6. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to any one of claims 1 to 3, characterized in that: In the mixed ore, the weight ratio of the copper-cobalt sulfide concentrate to the iron-aluminum slag is (5-8):

1.

7. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to any one of claims 1 to 3, characterized in that: In the step S2, the liquid-to-solid ratio of the mixed slurry is (4-12):1, and the mixed slurry is carried out at a stirring speed of 300 r / min-800 r / min.

8. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to any one of claims 1 to 3, characterized in that: In the step S3, an inorganic acid solution and / or an organic acid solution with a mass concentration of 50% to 98% is used as the acid solution for the pre-acid leaching.

9. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to any one of claims 1 to 3, characterized in that: In step S3, the pre-acid leaching temperature is 25° C. to 80° C., and the pre-acid leaching time is 60 min to 120 min.

10. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to any one of claims 1 to 3, characterized in that: In step S4, the temperature of the oxygen pressure leaching is 160° C. to 220° C.; and the pH value of the leaching solution is 1 to 2.5.

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