Dump leaching treatment method for copper-cobalt ore

Abstract

The invention belongs to the technical field of metallurgy, and discloses a dump leaching treatment method for copper-cobalt ore. Comprising the following steps: (1) respectively crushing copper-cobalt sulfide ore and copper-cobalt oxide ore; (2) carrying out biological dump leaching on the crushed copper-cobalt sulfide ore and copper-cobalt oxide ore to obtain dump leaching liquid; (3) the dump leaching liquid is subjected to extraction-electrodeposition treatment, a cathode copper product is obtained, and raffinate serves as spraying liquid and returns to the step (2) to be recycled; wherein the acid consumption of the copper oxide-cobalt ore is A kg / t ore, the net acid yield of the copper sulfide-cobalt ore is B kg / t ore, and in the step (2), the ore loading and stacking mass ratio of the copper oxide-cobalt ore to the copper sulfide-cobalt ore is B / A: 1. In the heap leaching process, sulfuric acid or a neutralizing agent does not need to be additionally added, dynamic acid balance of the heap leaching system is achieved, the technological process is simple, production operation is convenient, industrial application is easy to achieve, and remarkable economic benefits are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a heap leaching method for copper-cobalt ore. Background Art

[0002] Copper and cobalt often coexist in one or more minerals to form copper-cobalt ores due to their similar geochemical properties. Copper and cobalt are divided into oxide ores and sulfide ores according to their oxidation degree. The two types of ores use different smelting processes due to their different physical and chemical properties. Generally, oxide ores are directly stirred and leached, while sulfide ores are treated by pyrolysis or oxidized or sulphated and roasted before stirring and leaching.

[0003] As ore mining continues to deepen, low-grade copper-cobalt ores containing Cu < 0.8wt% and Co < 0.2wt% will gradually be produced. This type of ore cannot be used economically and effectively, so it is overstocked, resulting in waste of resources and capital backlog. Domestic and foreign researchers have conducted a variety of beneficial explorations on the rational utilization of low-grade copper-cobalt ores, among which the most studied is heap leaching technology.

[0004] Compared with the stirring leaching process, heap leaching has the advantages of simple ore pretreatment and large processing scale, which can greatly reduce the cost of ore processing and make the development and utilization of low-grade copper-cobalt ore possible. Usually, low-grade oxidized copper-cobalt ore contains more alkaline substances such as talc, chlorite and dolomite. A large amount of sulfuric acid needs to be added during the copper-cobalt heap leaching process, which greatly reduces the economic efficiency of its treatment. Under the action of bacteria, copper-cobalt sulfide ore will convert the S in the ore into 2- Oxidation to SO 4 2- , after extraction or hydrolysis and precipitation of metal ions, it is finally converted into sulfuric acid, resulting in excess acid in the system. Exploring the combined treatment of the two ores is an effective way to develop and apply low-grade copper-cobalt ores.

[0005] The patent with publication number CN104674002A discloses a low-grade copper ore bioleaching process, in which low-grade copper ore is mixed with copper concentrate in a certain proportion, and the mixture is evenly mixed and piled up for bioleaching. Bioleaching and acid production are carried out simultaneously, so that no external sulfuric acid is required during the copper ore bio-heap leaching process, and the acid balance inside the heap leaching system is achieved. However, this method uses copper sulfide concentrate as an acid-producing mineral, which is not economically reasonable. The copper sulfide concentrate is mainly primary sulfide ore. During the bioleaching process, the copper leaching rate is low, resulting in a waste of copper resources. In addition, the low-grade copper ore and the copper concentrate need to be fully mixed before heap leaching, which requires high operation intensity.

[0006] The patent application with publication number CN1566377A discloses a combined heap leaching process for copper ore, which uses bacteria to leach copper sulfide ore, and uses the dilute sulfuric acid solution produced by bacterial leaching of copper sulfide ore to spray or drip the copper oxide ore heap. The copper-containing leaching solution is purified and impurities are removed before extraction and electrolysis to produce high-purity cathode copper. However, this process heap-leaches copper sulfide ore and copper oxide ore separately, and the two are simply connected in series, without considering the acid balance between the acid produced by the sulfide ore and the acid consumed by the oxide ore, and the production process is complicated. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention aims to provide a heap leaching method for copper-cobalt ore. The method utilizes the leaching characteristics of sulfide ore and oxide ore to efficiently recover copper and cobalt metals while achieving acid profit and loss balance in the process.

[0008] To achieve the purpose of the present invention, the specific technical scheme is as follows: A heap leaching method for copper-cobalt ore comprises the following steps: (1) Take copper-cobalt sulfide ore and copper-cobalt oxide ore and crush them separately; (2) subjecting the crushed copper-cobalt sulfide ore and copper-cobalt oxide ore to biological heap leaching to obtain heap leaching liquid; (3) sending the heap leaching liquid to the copper extraction process, electrolyzing the obtained extract to produce cathode copper, and returning the obtained raffinate as the spray liquid to step (2) for recycling; In step (2), the average acid consumption of the copper-cobalt oxide ore is A kg / t ore, the average net acid production of the copper-cobalt sulfide ore is B kg / t ore, and the stacking mass ratio of the copper-cobalt oxide ore to the copper-cobalt sulfide ore is B / A:1.

[0009] The copper-cobalt ore described in the present invention is not particularly limited to the metal grades of copper, cobalt, etc. However, as one of the further preferred embodiments, the present invention is particularly suitable for low-grade copper-cobalt ore, in which Cu is less than 0.8wt% and Co is less than 0.2wt%.

[0010] The oxidation rates of the sulfide ore and the oxide ore described in the present invention are not particularly limited, and the mixed ore containing the two is also within the range. However, as one of the further preferred embodiments, the sulfide ore is a deep ore with an oxidation rate lower than 30%, and the oxide ore is a surface ore with an oxidation rate higher than 30%. The oxidation rate is the ratio of the content of oxide minerals in the ore to the total amount of the ore.

[0011] Furthermore, in step (1), the copper-cobalt sulfide ore and the copper-cobalt oxide ore are crushed to a particle size P 80 =5~50mm.

[0012] Furthermore, the acid consumption of copper-cobalt oxide ore and the acid production of copper-cobalt sulfide ore can be more accurately calculated through laboratory small-scale leaching tests. The production and acid consumption of the ore can also be roughly estimated through the content of sulfur, calcium, magnesium and other elements in the ore.

[0013] The biological heap leaching of the present invention refers to spraying the ore heap with a spray liquid containing microorganisms, using microbial leaching technology to dissolve copper in the ore through the catalytic action of microorganisms.

[0014] Furthermore, in the process of biological heap leaching, the present invention first carries out heap construction, then starts spraying and begins biological heap leaching.

[0015] Furthermore, during the first spraying of a new reactor startup: Acidithiobacillus is added to the acidic aqueous solution as a spraying liquid.

[0016] Further preferably, the Acidithiobacillus is Acidithiobacillus ferrooxidans.

[0017] Furthermore, the acidic aqueous solution is one or more acidic solutions of commonly used inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, etc.

[0018] More preferably, the pH value of the acidic aqueous solution is 0-6.

[0019] Further preferably, in the heap leaching treatment method of copper-cobalt ore of the present invention, in the actual biological heap leaching process, by real-time monitoring of acid balance data, according to the requirements of acid consumption and acid production, copper-cobalt sulfide ore acid production or copper-cobalt oxide ore acid production is added to control the dynamic balance of the overall ore acid production and acid consumption, thereby maintaining the total ore acid consumption = total net acid production during a complete cycle of biological heap leaching.

[0020] Furthermore, in step (2), the stacking method is one of the following: the copper-cobalt oxide ore and the copper-cobalt sulfide ore are alternately stacked to form a multi-layer ore pile, the copper-cobalt oxide ore and the copper-cobalt sulfide ore are evenly mixed to form a mixed ore pile, and the copper-cobalt oxide ore and the copper-cobalt sulfide ore are separately stacked to form a plurality of small ore piles to form an ore pile group.

[0021] Furthermore, in step (2), during the bio-heap leaching process: using the raffinate obtained in step (3) as a spraying liquid; Further preferably, the spray intensity is 6-20 L / m 2 ·h.

[0022] More preferably, the heap leaching time is 30 to 300 days.

[0023] Furthermore, in step (2), the copper ion concentration C in the heap leaching solution is Cu2+ As a basis for judgment, if C Cu2+ ≥3g / L, proceed to step (3); if C Cu2+<3g / L, sent to the intermediate liquid pool, circulated and sprayed until the copper ion concentration in the intermediate liquid pool reaches the extraction requirement, and then sent to step (3).

[0024] Furthermore, in step (3), part of the raffinate is opened, neutralized and precipitated to recover cobalt.

[0025] Compared with the prior art, the beneficial effects of the present invention are: The present application creatively mixes the acid-generating sulfide ore and the acid-consuming oxide ore in the heap leaching process according to the principle of maintaining the acid balance of the system, without the need to add additional sulfuric acid or neutralizing agent, to achieve the dynamic acid balance of the heap leaching system, and then achieves the dynamic acid balance of the whole heap leaching-extraction-electrodeposition system, while efficiently recovering copper and cobalt metals.

[0026] The process of the present invention is simple, easy to operate, and can be easily industrialized and applied, thus having significant economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a schematic flow diagram of the heap leaching method of copper-cobalt ore of the present invention. DETAILED DESCRIPTION

[0028] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings and preferred embodiments of the present invention, but the protection scope of the present invention is not limited to the following specific embodiments.

[0029] Unless otherwise defined, all the 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.

[0030] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0031] Example 1 This embodiment provides a heap leaching method for copper-cobalt ore, such as Figure 1 As shown, the specific steps are as follows: Take copper-cobalt sulfide ore, whose main components are Cu 0.83wt%, Co 0.26wt%, S 1.21wt%; copper-cobalt oxide ore, whose main components are Cu 0.68wt%, Co 0.17wt%; both are crushed to P80-30mm.

[0032] The test results show that the acid consumption of copper-cobalt oxide ore is 52.0kg / t ore, and the net acid production of copper-cobalt sulfide ore is 13.8kg / t.

[0033] The two crushed ores are piled up in an alternating manner, and the loading ratio is determined according to the test acid production and acid consumption data. In the actual biological heap leaching process, by real-time monitoring of the acid balance data, according to the requirements of acid consumption and acid production, copper cobalt sulfide ore is added to produce acid or copper cobalt oxide ore is added to consume acid, thereby controlling the dynamic balance of the overall ore acid production and acid consumption. In this embodiment, the mass ratio of copper cobalt oxide ore and copper cobalt sulfide ore in the pile is 0.265 / 1.

[0034] In this embodiment, Thiobacillus ferrooxidans is added to the sulfuric acid solution as a spray liquid for spraying during the first spraying of the new stack startup; subsequently, the heap leaching liquid is subjected to extraction-electrowinning treatment to obtain a cathode copper product, and the raffinate is used as a spray liquid for spray circulation.

[0035] In this embodiment, the spray intensity is controlled to be 10L / m 2 ·h, the spraying cycle is 180 days.

[0036] in: During the spray cycle, the main components of the raffinate obtained for the first time were Cu 0.87 g / L, Co 1.53 g / L, H 2 SO 4 12.53g / L.

[0037] The raffinate is used as the spraying liquid for spraying. During the spraying process, the copper ion concentration in the leaching liquid is used as the judgment basis. If C Cu2+ ≥3g / L, that is, pumped to the extraction process, if C Cu2+ <3g / L, that is, pump it into the intermediate liquid pool and circulate and spray until the copper ion concentration in the heap leaching liquid reaches the extraction requirement.

[0038] After the spraying was completed, the copper and cobalt leaching rates were calculated to be 83.2% and 67.5% respectively.

[0039] The heap leaching liquid is subjected to conventional extraction-electrowinning treatment to obtain cathode copper products, and part of the raffinate is open-circuited to recover metallic cobalt through neutralization and precipitation. Part of the raffinate is returned to the heap leaching process as the next spray liquid.

[0040] The sulfuric acid concentration in the returned raffinate is 13.02 g / L, which is not much different from the initial sulfuric acid concentration of the raffinate of 12.53 g / L, indicating that the acid content in the system remains basically unchanged and acid balance is achieved.

[0041] Example 2 This embodiment provides a heap leaching method for copper-cobalt ore, such as Figure 1 As shown, the specific steps are as follows: Take copper-cobalt sulfide ore, whose main components are Cu 1.05wt%, Co 0.23wt%, S 1.53wt%; copper-cobalt oxide ore, whose main components are Cu 0.72wt%, Co 0.27wt%; both are crushed to P80-30mm.

[0042] The test results show that the acid consumption of copper-cobalt oxide ore is 73.7kg / t ore, and the net acid production of copper-cobalt sulfide ore is 17.2kg / t.

[0043] The two crushed ores are piled up in an alternating manner, and the loading ratio is determined according to the test acid production and acid consumption data. In the actual biological heap leaching process, by real-time monitoring of the acid balance data, according to the requirements of acid consumption and acid production, copper cobalt sulfide ore is added to produce acid or copper cobalt oxide ore is added to consume acid, thereby controlling the dynamic balance of the overall ore acid production and acid consumption. In this embodiment, the ratio of copper cobalt oxide ore and copper cobalt sulfide ore to pile up is 0.233 / 1.

[0044] In this embodiment, Thiobacillus ferrooxidans is added to the sulfuric acid solution as a spray liquid for spraying during the first spraying of the new stack startup; subsequently, the heap leaching liquid is subjected to extraction-electrowinning treatment to obtain a cathode copper product, and the raffinate is used as a spray liquid for spray circulation.

[0045] In this embodiment, the spray intensity is controlled to be 8L / m 2 ·h, the spraying cycle is 200 days.

[0046] in: During the spray cycle, the main components of the raffinate obtained for the first time were Cu 0.56 g / L, Co 0.83 g / L, H 2 SO 4 14.33g / L.

[0047] The raffinate is used as the spraying liquid for spraying. During the spraying process, the copper ion concentration in the leaching liquid is used as the judgment basis. If C Cu2+ ≥3g / L, that is, pumped to the extraction process, if C Cu2+ <3g / L, that is, pump it into the intermediate liquid pool and circulate and spray until the copper ion concentration in the heap leaching liquid reaches the extraction requirement.

[0048] After the spraying was completed, the copper and cobalt leaching rates were calculated to be 85.64% and 68.71% respectively.

[0049] The heap leaching liquid is subjected to conventional extraction-electrowinning treatment to obtain cathode copper products, and part of the raffinate is open-circuited to recover metallic cobalt through neutralization and precipitation. Part of the raffinate is returned to the heap leaching process as the next spray liquid.

[0050] The sulfuric acid concentration in the returned raffinate is 14.18 g / L, which is not much different from the initial sulfuric acid concentration of the raffinate of 14.33 g / L, indicating that the acid content in the system remains basically unchanged and acid balance is achieved.

[0051] Example 3 This embodiment provides a heap leaching method for copper-cobalt ore, such as Figure 1 As shown, the specific steps are as follows: Take copper-cobalt sulfide ore, whose main components are Cu 0.67wt%, Co 0.18wt%, S 0.98wt%; copper-cobalt oxide ore, whose main components are Cu 0.65wt%, Co 0.23wt%; both are crushed to P80-20mm.

[0052] The test results show that the acid consumption of copper-cobalt oxide ore is 32.5kg / t ore, and the net acid production of copper-cobalt sulfide ore is 11.7kg / t.

[0053] The two crushed ores are piled separately, and the leaching liquid is mixed in the liquid pool. The heap loading ratio of the oxide ore and the sulfide ore is determined according to the test acid production and acid consumption data. In the actual biological heap leaching process, by real-time monitoring of the acid balance data, according to the demand for acid consumption and acid production, the sulfide copper-cobalt ore is added to produce acid or the oxide copper-cobalt ore is added to consume acid, thereby controlling the dynamic balance of the overall ore acid production and acid consumption. In this embodiment, the mass ratio of the oxide copper-cobalt ore and the sulfide copper-cobalt ore is 0.36 / 1.

[0054] In this embodiment, Thiobacillus ferrooxidans is added to the sulfuric acid solution as a spray liquid for spraying during the first spraying of the new stack startup; subsequently, the heap leaching liquid is subjected to extraction-electrowinning treatment to obtain a cathode copper product, and the raffinate is used as a spray liquid for spray circulation.

[0055] In this embodiment, the spray intensity is controlled to be 8L / m 2 ·h, the spraying cycle is 200 days.

[0056] in: During the spray cycle, the main components of the raffinate obtained for the first time were Cu 0.87 g / L, Co 1.35 g / L, H 2 SO 4 10.86g / L.

[0057] The raffinate is used as the spraying liquid for spraying. During the spraying process, the copper ion concentration in the leaching liquid is used as the judgment basis. If C Cu2+ ≥3g / L, that is, pumped to the extraction process, if C Cu2+ <3g / L, that is, pump it into the intermediate liquid pool and circulate and spray until the copper ion concentration in the heap leaching liquid reaches the extraction requirement.

[0058] After the spraying was completed, the copper and cobalt leaching rates were calculated to be 83.77% and 72.39% respectively.

[0059] The heap leaching liquid is subjected to conventional extraction-electrowinning treatment to obtain cathode copper products, and part of the raffinate is open-circuited to recover metallic cobalt through neutralization and precipitation. Part of the raffinate is returned to the heap leaching process as the next spray liquid.

[0060] The sulfuric acid concentration in the returned raffinate is 11.18 g / L, which is not much different from the initial sulfuric acid concentration of the raffinate of 10.86 g / L, indicating that the acid content in the system remains basically unchanged and acid balance is achieved.

[0061] Comparative Example Low-grade copper-cobalt oxide ore is used for heap leaching, with the main components of Cu 0.72wt% and Co 0.18wt% being crushed to P100-20mm and then piled on trucks.

[0062] According to the test results, the acid consumption of the oxide ore is 63.6kg / t ore.

[0063] After the pile is built, Thiobacillus ferrooxidans is added to the sulfuric acid solution as a spraying liquid for spraying during the first spraying of the new pile; subsequently, the heap leaching liquid is subjected to extraction-electrowinning treatment to obtain a cathode copper product, and the raffinate is used as a spraying liquid for spraying circulation.

[0064] Control the spray intensity to 8L / m 2 ·h, the spraying cycle is 100 days.

[0065] in: During the spray cycle, the main components of the raffinate obtained for the first time were Cu 0.35 g / L, Co 1.22 g / L, H 2 SO 4 11.78g / L.

[0066] The raffinate is used as the spraying liquid for spraying. During the spraying process, the copper ion concentration in the leaching liquid is used as the judgment basis. If C Cu2+ ≥3g / L, that is, pumped to the extraction process, if C Cu2+ <3g / L, that is, pump it into the intermediate liquid pool and circulate and spray until the copper ion concentration in the heap leaching liquid reaches the extraction requirement.

[0067] In the spraying process of this comparative example, after the qualified heap leaching liquid is extracted, the sulfuric acid concentration in the raffinate drops significantly to only 5.23g / L. When it is sprayed again as a spray liquid, sulfuric acid needs to be added to adjust the acidity to about 10g / L. During the entire leaching cycle, nearly 10 tons of sulfuric acid need to be added for every ton of copper produced, which seriously affects the economic efficiency of processing this ore, so that it can only be discharged as waste rock, resulting in a waste of resources.

[0068] The above are only 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 in the scope of the present invention.

Claims

1. A heap leaching method for copper-cobalt ore, characterized in that: The following steps are involved: (1) Take copper-cobalt sulfide ore and copper-cobalt oxide ore and crush them separately; (2) subjecting the crushed copper-cobalt sulfide ore and copper-cobalt oxide ore to biological heap leaching to obtain heap leaching liquid; (3) subjecting the heap leaching liquid to extraction-electrowinning treatment to obtain a cathode copper product, and returning the raffinate as a spray liquid to step (2) for recycling; In step (2), the average acid consumption of the copper-cobalt oxide ore is A kg / t ore, the average net acid production of the copper-cobalt sulfide ore is B kg / t ore, and the stacking mass ratio of the copper-cobalt oxide ore to the copper-cobalt sulfide ore is B / A:

1.

2. The heap leaching method of copper-cobalt ore according to claim 1, characterized in that: In the copper-cobalt ore, Cu is less than 0.8wt% and Co is less than 0.2wt%.

3. The heap leaching method of copper-cobalt ore according to claim 1, characterized in that: The copper-cobalt sulfide ore is a deep ore with an oxidation rate lower than 30%, and the copper-cobalt oxide ore is a surface ore with an oxidation rate higher than 30%.

4. The heap leaching method of copper-cobalt ore according to claim 1, characterized in that: In step (1), the copper-cobalt sulfide ore and the copper-cobalt oxide ore are crushed to a particle size P 80 =5~50mm.

5. The heap leaching method of copper-cobalt ore according to any one of claims 1 to 4, characterized in that: In step (2), the bio-heap leaching specifically comprises: spraying the ore heap with a spray liquid containing microorganisms.

6. The heap leaching method of copper-cobalt ore according to claim 5, characterized in that: In step (2), during the first spraying of the new stack at startup: Acidithiobacillus is added to the acidic aqueous solution as a spraying liquid; preferably, the Acidithiobacillus is Thiobacillus ferrooxidans.

7. The heap leaching method of copper-cobalt ore according to claim 5, characterized in that: In step (2), during the bioleaching process: Using the raffinate obtained in step (3) as a spray liquid; Spray intensity is 6~20L / m 2 ·h; The heap leaching time is 30 to 300 days.

8. The heap leaching method of copper-cobalt ore according to claim 1, characterized in that: In step (2), during the bio-heap leaching process, the stacking method is one of the following: alternately stacking the copper-cobalt oxide ore and the copper-cobalt sulfide ore to form a multi-layer ore heap, mixing the copper-cobalt oxide ore and the copper-cobalt sulfide ore evenly to form a mixed ore heap, and stacking the copper-cobalt oxide ore and the copper-cobalt sulfide ore separately to form a ore heap group formed by multiple small ore heaps.

9. The heap leaching method of copper-cobalt ore according to claim 1, characterized in that: In step (2), the copper ion concentration C in the heap leaching solution is Cu2+ As a basis for judgment, if C Cu2+ ≥3g / L, proceed to step (3); if C Cu2+ <3g / L, sent to the intermediate liquid pool, circulated spraying, until the copper ion concentration in the intermediate liquid pool is C Cu2+ ≥3g / L, proceed to step (3).

10. The heap leaching method of copper-cobalt ore according to claim 1, characterized in that: In step (3), part of the raffinate is opened, neutralized and precipitated to recover cobalt.

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