Method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate

Abstract

The present invention provides a method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate. The method includes: mixing the copper-cobalt sulfide concentrate with iron-aluminum slag for ore blending to obtain a mixed ore; mixing the mixed ore with water for pulp preparation to obtain a first pulp; subjecting the first pulp to pre-acid leaching at an acid-ore ratio of 150 kg / t to 220 kg / t to obtain a second pulp; subjecting the second pulp to oxygen pressure leaching and performing solid-liquid separation to obtain a leaching solution. The iron-aluminum slag is the waste slag precipitated in the process of neutralizing and removing iron and aluminum during the treatment of cobalt and copper in copper-cobalt sulfide ore. By mixing the copper-cobalt sulfide concentrate with iron-aluminum slag for ore blending, the present invention not only effectively improves the leaching rate of valuable metals Co and Cu in the copper-cobalt sulfide concentrate, but also realizes the resource recycling of the iron-aluminum slag generated during the treatment of cobalt and copper in copper-cobalt sulfide ore, reduces environmental pollution, and lowers production costs.

Description

Technical Field

[0001] The present 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 often exist in the form of associated minerals in sulfide ores, arsenide ores, and oxide ores. Among them, copper-cobalt sulfide ore is one of the common raw materials in the nickel-cobalt hydrometallurgy industry. Industrially, the sulfation roasting-leaching process is often used to treat copper-cobalt sulfide concentrate. Regarding the leaching process, pressure leaching has the advantages of being able to treat complex polymetallic sulfide ores, extracting multiple valuable metals simultaneously, having a high metal extraction rate, and combining the leaching and iron removal processes into one. Cominco Company in Canada has developed the CESL technology for pressure leaching copper-cobalt concentrate, and the leaching solution is sent to the solvent extraction-electrowinning system to produce pure copper and pure cobalt.

[0003] The extraction processes for 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 processes. Among them, the pyrometallurgy process has been basically phased out due to its high energy consumption, heavy environmental pollution, and strong corrosion to equipment. The ammonia extraction process has also been basically phased out due to the high price of ammonia extractant. 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 consumption of ammonia extractant is large, and malodorous by-products are easily generated during the recovery process of ammonia extractant. The wet acid leaching + carbonate reverse flotation process has a high consumption of carbonate reverse flotation agents, and a large amount of medium- and low-quality flotation foam is generated during the reverse flotation process. The flotation foam will cause serious corrosion of equipment and unstable production. The wet acid leaching + oxygen pressure leaching process has the advantages of simple operation, short process, low corrosion of equipment, and high product purity. However, the oxygen pressure leaching has a low oxidation degree of S, Fe, and Al in copper-cobalt sulfide concentrate, and there is a large amount of leaching residue after oxygen pressure leaching. The treatment cost of leaching residue is high and the treatment difficulty is large, which is not conducive to the recovery of valuable metals in copper-cobalt sulfide concentrate.

[0004] That is to say, at present, for the oxygen pressure leaching method of copper-cobalt sulfide concentrate, there are still problems such as low leaching recovery rate of metal elements and cumbersome process with 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 the 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 for cobalt-sulfur concentrate and cobalt hydroxide ore. By leaching cobalt-sulfur concentrate and cobalt hydroxide ore under high pressure, sulfur ions are oxidized to sulfate ions, ferrous ions are oxidized to ferric ions, and the generated hydrogen ions are used to leach cobalt hydroxide. At the same time, cobalt, copper, and nickel in the cobalt-sulfur concentrate are also leached into the solution. However, the above two solutions only improve the oxygen pressure leaching efficiency of Co and Cu elements, and the recovery of other elements such as Fe and Al is not good. At the same time, there is still room for improvement in the recovery rate of each element, and the consumption of subsequent processes is large.

[0005] At the same time, iron-aluminum precipitation slag is generated during the treatment of copper-cobalt ore, which contains a small amount of Ni and Co. If Ni and Co are recovered, a large amount of neutralizing agent will be consumed in the process of secondary neutralization precipitation, and the economy is poor.

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

[0007] The main object of the present invention is to provide a method for leaching and extracting cobalt and copper from 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 at the same time it is difficult to effectively recycle the iron-aluminum precipitation slag generated during the treatment of cobalt sulfide ore.

[0008] To achieve the above object, the present invention provides a method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate, comprising: Step S1, mixing and proportioning the copper-cobalt sulfide concentrate with 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 for pulp mixing to obtain a first pulp; Step S3, pre-acid leaching the first pulp according to an acid-ore ratio of 150 kg / t - 220 kg / t to obtain a second pulp; Step S4, performing oxygen pressure leaching on the second pulp at an oxygen partial pressure of 0.3 MPa - 1.2 MPa, a stirring speed of 600 r / min - 900 r / min, and a time of 0.8 h - 3.0 h, and performing solid-liquid separation to obtain a leaching solution; the iron-aluminum slag is the waste slag precipitated in the process of neutralizing and removing iron and aluminum during the cobalt and copper extraction process of copper-cobalt sulfide ore.

[0009] Further, by weight, the iron-aluminum 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.

[0010] Further, 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.

[0011] Further, based on the total weight of the copper-cobalt sulfide concentrate being 100%, the proportion of the copper-cobalt sulfide concentrate with a particle size of 200 mesh is 97% - 99%; and / or, based on the total weight of the iron-aluminum slag being 100%, the proportion of the iron-aluminum slag with a particle size of 150 mesh is 98% - 99%.

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

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

[0014] Further, in Step S2, the liquid-solid ratio of the pulp mixing is (4 - 12):1, and the pulp mixing is performed at a stirring speed of 300 r / min - 800 r / min.

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

[0016] Still further, in Step S3, the temperature of the pre-acid leaching is 25°C - 80°C, and the time is 60 min - 120 min.

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

[0018] Applying the technical solution of the present invention, by mixing and proportioning the copper-cobalt sulfide concentrate with the iron-aluminum slag, not only effectively improves the leaching rate of valuable metals Co and Cu in the copper-cobalt sulfide concentrate, but also realizes the resource recycling of the iron-aluminum slag generated during the cobalt and copper extraction process of the copper-cobalt sulfide ore, reduces environmental pollution, and lowers the production cost. Specific embodiments

[0019] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0020] As described in the background art, in the prior art, it is impossible 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. That is to say, there is a problem that it is impossible to achieve the leaching and extraction of cobalt and copper elements in the copper-cobalt sulfide concentrate with high selectivity. At the same time, there is also a problem in the prior art that it is difficult to effectively recycle the iron-aluminum precipitate slag generated during the treatment of cobalt sulfide ore.

[0021] To solve the above technical problems, the present invention provides a method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate, including: step S1, mixing and proportioning 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 to 8):1; step S2, mixing the mixed ore with water for pulp mixing to obtain a first pulp; step S3, pre-acid leaching the first pulp according to an acid-ore ratio of 150 kg / t to 220 kg / t to obtain a second pulp; step S4, performing oxygen pressure leaching on the second pulp with 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 performing solid-liquid separation to obtain a leaching solution; the iron-aluminum slag is the waste slag precipitated in the process of neutralizing and removing iron and aluminum during the cobalt and copper extraction process of the copper-cobalt sulfide ore.

[0022] In the process of extracting cobalt and copper from copper-cobalt sulfide ore, the iron-aluminum slag generated in the process of removing iron and aluminum is reintroduced into the leaching process of copper-cobalt sulfide concentrate to be used as an inhibitor to suppress the leaching of aluminum during the leaching of copper-cobalt sulfide concentrate. This realizes the efficient suppression of the leaching of impurity elements such as iron and aluminum in copper-cobalt sulfide concentrate, the efficient leaching of valuable metals such as copper and cobalt therein, and at the same time realizes the effective recovery of a small amount of copper and cobalt in the iron-aluminum slag. Specifically, the weight ratio of copper-cobalt sulfide concentrate to 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 suppressed, and Ni and Co can be efficiently recovered. At the same time, at this weight ratio, the efficiency of oxygen pressure leaching can be significantly optimized, the leaching rates of copper and cobalt can be increased, while ensuring a lower leaching rate of iron and aluminum, and more effective separation and recovery of Ni and Co metals can be realized. At the same time, this acid-to-ore ratio can control the pH value during the reaction process and maintain it under the optimal acidic conditions, thereby ensuring the efficient leaching of metals while suppressing the leaching of other impurity elements that are not desired to dissolve (i.e., iron and aluminum). More importantly, since the acid-to-ore ratio in the pre-acid leaching process directly affects the consumption of sulfuric acid and the generation of sulfate radicals, an acid-to-ore ratio range of 150 kg / t to 220 kg / t can achieve a good balance of sulfate radicals in the second pulp, avoiding the generation of excessive sulfate radicals resulting in an excess of sulfuric acid in the solution, which in turn affects the treatment of the leaching solution and the recovery of Ni and Co metals. Finally, strictly controlling the conditions of oxygen pressure leaching for the above-mentioned special pulp system helps to provide sufficient oxidation leaching power, enabling more efficient oxidation, dissolution and leaching of metal sulfides in copper-cobalt sulfide concentrate, and also regulating the ease of oxidation of different metals during the leaching process, so as to suppress the leaching of impurities such as iron and aluminum while achieving a high leaching rate of copper and cobalt, and improving the purity, recovery efficiency and selectivity of metals.

[0023] It should be particularly noted that the above steps and corresponding conditions in the leaching and recovery method provided by the present invention cooperate with each other as an overall technical solution, that is, form a complete technical route of "mixing ores in a specific weight ratio → preparing pulp → pre-acid leaching with a specific acid-to-ore ratio → oxygen pressure leaching under specific conditions". In addition to the design of the process flow, it also includes the optimization of the parameter cooperation in each process stage. For the leaching of cobalt and copper in copper-cobalt sulfide concentrate, compared with the conventional methods commonly used in the art, including the pre-acid leaching + oxygen pressure leaching process, it can more effectively improve the leaching rates of Ni and Co, while significantly suppressing 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 their own advantages, more importantly, can cooperate with each other, that is, as an overall solution, to achieve the efficient and highly selective leaching and extraction of cobalt and copper in copper-cobalt sulfide concentrate.

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

[0025] In several typical embodiments, it is preferably to adopt an acid-to-ore ratio of 200 kg / t to 220 kg / t during the pre-acid leaching process to provide a sufficient acidic environment, so as to more effectively promote the dissolution of metal sulfides in the copper-cobalt sulfide concentrate and significantly improve the leaching rates of copper and cobalt.

[0026] Regarding the raw material of iron and aluminum slag, the inventor preferably selects, by weight parts, that the iron and aluminum slag contains 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 through a large number of experiments. For the iron and aluminum slag with this composition, the contents of Fe and Al are relatively high. At the same time, by coordinating the conditions of the above 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 leaching residue rather than leached into the solution, that is, it plays a good inhibitory role, so as to more effectively optimize the metal content of the leaching solution and improve the efficiency of subsequent metal separation and recovery.

[0027] Specifically, for the iron and aluminum slag with the above composition, it can be obtained from iron and aluminum-containing minerals such as copper-cobalt ore and copper-cobalt concentrate through processes such as acid leaching, alkali leaching, and oxidative leaching to generate insoluble substances such as ferric sulfate (Fe2(SO4)3) and aluminum sulfate (Al2(SO4)3), which remain in the oxygen pressure leaching residue in an insoluble form, thus forming iron and aluminum slag. And in this process, a small amount of Fe / Al will enter the leaching solution, and then through neutralization precipitation (adjusting the solution pH to 4.5 - 5.2), iron and aluminum ions can be precipitated into the slag to form iron and aluminum slag as well.

[0028] Regarding the main treatment object of copper-cobalt sulfide concentrate, by weight parts, it is preferably that the copper-cobalt sulfide concentrate contains 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, so as to better adapt to the above leaching method and achieve a higher cobalt and copper leaching rate.

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

[0030] To better adapt to the above particle size relationship, the inventor further optimized the weights of the two through a large number of experiments, making the weight ratio of the copper-cobalt sulfide concentrate to the iron-aluminum slag in the mixed ore (5 - 8):1, and thus obtaining a better leaching and extraction effect, more effectively improving the leaching rates of Cu and Co under the condition of inhibiting the leaching of Fe and Al.

[0031] After obtaining the mixed ore, preferably in step S2, the liquid-solid ratio of the mixed pulp preparation is (4 - 12):1, and the mixed pulp preparation is carried out at a stirring speed of 300 r / min - 800 r / min. The preference of the above pulp preparation conditions can obtain a first pulp 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 increasing the leaching rates of Co and Cu.

[0032] To adapt to the above pre-acid leaching conditions, to achieve pre-acid leaching and oxygen pressure leaching with higher efficiency and reduce the introduction of impurities, preferably in step S3, an inorganic acid solution and / or an organic acid solution with a mass concentration of 50% - 98% is used as the acid solution for pre-acid leaching; preferably the inorganic acid solution is a sulfuric acid solution. Compared with other types of acid solutions commonly used in the art, sulfuric acid with the above mass concentration, that is, the inorganic acid solution, is a strong acid, which 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) generated during the sulfuric acid leaching process can be further processed and utilized to reduce waste emissions.

[0033] In several typical embodiments, preferably in step S3, an organic acid solution with a molar concentration of 0.1 mol / L to 0.5 mol / 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 stable complexes with copper and cobalt, reduce the co-leaching of impurities, and thus can extract copper and cobalt more effectively, especially suitable for treating ores with low grade and complex composition as processed in the present invention. At the same time, the organic acid has less impact on the environment and has excellent environmental protection performance. Moreover, more preferably, the molar concentration of the organic acid used is 0.48 mol / L to 0.5 mol / 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] Furthermore, in step S3, in order to better balance the reaction efficiency in pre-acid leaching, and at the same time make the metal sulfide react more fully with the acid to improve the leaching rate, preferably the temperature of pre-acid leaching is 25°C to 80°C, and the time is 60 min to 120 min. Preferably, pre-acid leaching is carried out at a stirring speed of 300 r / min to 700 r / min, which can promote the uniform mixing of the pulp, accelerate the contact between reactants, and thus further improve the reaction rate and leaching efficiency. More preferably, step S4 is carried out when the pH value of the second pulp reaches 0.8 to 2. At this time, the pH value range of 0.8 to 2 can provide a strong acidic environment, promote the dissolution of metal sulfides, and at the same time inhibit the dissolution of certain impurity elements, such as Fe and Al. When the pH value reaches this range, it is preferably considered that the pre-acid leaching process is basically completed, and at this time, it is transferred to the oxygen pressure leaching step, which can promote the high-efficiency leaching of cobalt and copper metals, reduce the dissolution of impurities, and more significantly improve their leaching rate.

[0035] In several typical embodiments, in step S4, the temperature of oxygen pressure leaching is 160°C to 220°C. This temperature range can increase the oxidation reaction rate, accelerate the dissolution of metal sulfides such as copper and cobalt, and improve the leaching efficiency. At the same time, this temperature range is conducive to the deep oxidation of metal sulfides, converting insoluble sulfides into more soluble forms, thereby more effectively increasing the leaching rate of metals. In particular, this temperature can more effectively control the sulfate balance in the reaction system, optimize the generation amount of sulfate, maintain the chemical balance of the leaching solution, and is beneficial to subsequent metal separation, that is, the leaching of valuable metals in copper-cobalt sulfide concentrate is achieved with higher selectivity. In several more typical embodiments, the pH value of the leaching solution is 1 to 2.5. In the leaching solution 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 inhibited, and finally the purity of the leaching solution is improved and the high-selectivity recovery of metals is achieved.

[0036] The present application will be further described in detail below in conjunction with specific embodiments, which should not be construed as limiting the scope of protection required by the present application.

[0037] Unless otherwise defined, all professional terms used hereinafter have the same meaning as commonly 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] Provide copper-cobalt sulfide concentrate and iron-aluminum slag, and the composition contents of both 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 precipitation of the leaching solution of copper-cobalt sulfide concentrate.

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

[0042] Table 1

[0043]

[0044] (1) Take 100 g of copper-cobalt sulfide concentrate and 18 g of iron-aluminum slag for ore mixing to obtain a mixed ore; the weight ratio of copper-cobalt sulfide concentrate to iron-aluminum slag is 5.56:1;

[0045] (2) Control the liquid-solid ratio to be 8:1, and under the stirring speed of 500 r / min, prepare a pulp by mixing the mixed ore with water to obtain a first pulp;

[0046] (3) Use a sulfuric acid solution with a mass concentration of 98% as the acid solution, control the acid-ore ratio to be 200 kg / t, and under the operating conditions of 30 °C and a stirring speed of 500 r / min, perform pre-acid leaching on the first pulp for 60 min until its pH value is 0.9 to obtain a second pulp;

[0047] (4) Transfer the pulp after pre-acid leaching, that is, the second pulp, into an autoclave for oxygen pressure leaching, introduce oxygen, and perform oxygen pressure leaching under the conditions of 200 °C, an oxygen partial pressure of 0.4 Mpa, and a stirring speed of 800 r / min for 1 h. After solid-liquid separation, an leaching solution 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] Using the copper-cobalt sulfide concentrate and iron-aluminum slag used in Example 1 as treatment raw materials.

[0051] (1) Take 100 g of copper-cobalt sulfide concentrate and 34 g of iron-aluminum slag for ore mixing to obtain a mixed ore; the weight ratio of copper-cobalt sulfide concentrate to iron-aluminum slag is 2.94:1;

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

[0053] (3) Using a sulfuric acid solution with a mass concentration of 98% as the acid solution, control the acid-ore ratio to be 200 kg / t, and under the operating conditions of 30 °C and a stirring speed of 500 r / min, perform pre-acid leaching on the first pulp for 60 min until its pH value is 0.9 to obtain a second pulp;

[0054] (4) Transfer the pulp after pre-acid leaching, that is, the second pulp, into an autoclave for oxygen pressure leaching, introduce oxygen, and perform oxygen pressure leaching under the conditions of 200 °C, an oxygen partial pressure of 0.4 Mpa, and a stirring speed of 800 r / min for 1 h. After solid-liquid separation, an leaching solution 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] Using the copper-cobalt sulfide concentrate and iron-aluminum slag used in Example 1 as treatment raw materials.

[0058] (1) Take 100 g of copper-cobalt sulfide concentrate and 12.5 g of iron-aluminum slag for ore mixing to obtain a mixed ore; the weight ratio of copper-cobalt sulfide concentrate to iron-aluminum slag is 8.00:1;

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

[0060] (3) Using a sulfuric acid solution with a mass concentration of 98% as the acid solution, control the acid-ore ratio to be 200 kg / t, and under the operating conditions of 30 °C and a stirring speed of 500 r / min, perform pre-acid leaching on the first pulp for 60 min until its pH value is 0.9 to obtain a second pulp;

[0061] (4) The pulp after preliminary acid leaching, i.e., the second pulp, is transferred into an autoclave for oxygen pressure leaching. Oxygen is introduced, and oxygen pressure leaching is carried out under the conditions of 200 °C, an oxygen partial pressure of 0.4 Mpa, and a stirring speed of 800 r / min for 1 h. After solid-liquid separation, a leaching solution 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 difference between this example and Example 1 is only that the liquid-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 difference between this example and Example 1 is only that the acid-to-ore ratio in step (3) is changed to 150 kg / t, and the pH value of the resulting second pulp is changed to 2.

[0068] Example 6

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

[0070] The difference between this example and Example 1 is only that the acid-to-ore ratio in step (3) is changed to 220 kg / t, and the pH value of the resulting second pulp 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 difference between this example and Example 1 is only that the preliminary acid leaching time in step (3) is changed to 120 min.

[0074] Example 8

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

[0076] The difference between this example and Example 1 is only 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 difference between this example and Example 1 is only 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 difference between this example and Example 1 is only that the oxygen pressure leaching time in step (4) is changed to 0.8 h.

[0083] Example 11

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

[0085] The difference between this example and Example 1 is only 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 difference between this example and Example 1 is only that the D50 of the treated copper-cobalt sulfide concentrate is changed to 80 mesh, and the D50 of the treated iron-aluminum slag is changed to 50 mesh.

[0089] Example 13

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

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

[0092] Example 14

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

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

[0095] Example 15

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

[0097] The difference between this example and Example 1 is only 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 difference between this embodiment and Embodiment 1 is only 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, and the time is changed to 140 min. At this time, the pH value of the obtained second pulp 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 difference between this embodiment and Embodiment 1 is only 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, and the time is changed to 40 min. At this time, the pH value of the obtained second pulp 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 difference between this embodiment and Embodiment 1 is only that the temperature of the 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 difference between this embodiment and Embodiment 1 is only that the temperature of the 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 difference between this embodiment and Embodiment 1 is only that the sulfuric acid solution used in the pre-acid leaching in step (3) is replaced with 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 difference between this comparative example and Embodiment 1 is only that instead of adding iron-aluminum slag, 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 only that the dosage of iron-aluminum slag in step (1) is changed to 50 g, and at this time, the weight ratio of copper-cobalt sulfide concentrate to iron-aluminum 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 only that the dosage of iron-aluminum slag in step (1) is changed to 10 g, and at this time, the weight ratio of copper-cobalt sulfide concentrate to iron-aluminum 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 difference between this comparative example and Example 1 is only that the acid-to-ore ratio in step (3) is changed to 120 kg / t, and at this time, the pH value of the obtained second pulp 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 difference between this comparative example and Example 1 is only 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 difference between this comparative example and Example 1 is only 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 difference between this comparative example and Example 1 is only 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 difference between this comparative example and Example 1 is only 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 difference between this comparative example and Example 1 is only that an equal weight of aluminum sulfate is used to replace the iron-aluminum slag.

[0140] For the leaching solutions obtained in each example and comparative example, the leaching rates of Co, Cu, Fe, and Al elements are shown in Table 2.

[0141] Table 2

[0142]

[0143] From the above description, it can be seen that the above embodiments of the present invention realize the effective utilization of the iron-aluminum precipitation slag generated in the process of treating copper-cobalt sulfide ore, introduce it into the leaching process of cobalt and copper in copper-cobalt sulfide concentrate, and achieve higher leaching rates of cobalt and copper elements.

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

[0145] Among them, regarding Example 14 and Example 15, the decrease in the stirring speed will have a certain impact on the reaction degree and leaching rate. When the stirring speed is increased, the leaching rates of copper and cobalt increase correspondingly, but the leaching rates of impurities such as Fe also increase correspondingly. Therefore, the present invention preferably performs the mixing and pulp adjustment in step S2 at a stirring speed of 300 r / min to 800 r / min, so as to match the composition of the pulp to be treated, obtain a first pulp 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 finally increasing the leaching rates of Co and Cu under the condition of reducing the leaching rate of impurities.

[0146] In addition, in Comparative Example 7, when the oxygen partial pressure increases, the leaching rate of elements will increase correspondingly. However, under this condition, copper will be wrapped by iron, so its leaching rate is significantly reduced, and the comprehensive 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 do not have to be used to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances, so that the embodiments of the present application described here can be implemented in an order other than those described here, for example.

[0148] The above are only the preferred embodiments of the present invention and are 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 within 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 the 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; The iron-aluminum 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 in parts by weight; The D50 of the copper-cobalt sulfide concentrate is 100-150 mesh; the D50 of the iron-aluminum slag is 80-20 mesh.

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 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.

3. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to claim 1 or 2, 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%.

4. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to claim 1 or 2, 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.

5. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to claim 1 or 2, 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.

6. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to claim 1 or 2, 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.

7. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to claim 1 or 2, 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.

8. The method for leaching and extracting cobalt and copper from copper-cobalt sulfide concentrate according to claim 1 or 2, 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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