Method for neutralizing raffinate by using cobalt dolomite with low copper content and synchronously recovering copper and cobalt

Abstract

The invention relates to a method for neutralizing raffinate with cobalt dolomite with low copper content and synchronously recovering copper and cobalt, which comprises the following steps: carrying out neutralization reaction on raw ore pulp of cobalt dolomite and raffinate I to obtain neutralized ore pulp; carrying out solid-liquid separation on the neutralized ore pulp to obtain neutralized feed liquid and neutralized slag; the neutralization slag and the raffinate II are mixed and leached to obtain leached ore pulp; and carrying out solid-liquid separation on the leached ore pulp to obtain leached material liquid and leached residues. The cobalt dolomite with low copper content is used as a neutralizer of the raffinate, so that the problem of waste caused by difficult recovery of copper and cobalt metals in the cobalt dolomite with low copper content in the prior art is solved, and meanwhile, the problems of high cost and high investment when lime is used for neutralizing the raffinate are fundamentally solved.

Description

Technical Field

[0001] The present invention relates to the field of hydrometallurgy, and particularly to a method for recovering copper and cobalt by neutralizing raffinate with cobalt dolomite containing low copper. Background Art

[0002] The Central African copper belt (Lufilian arc) is located within the Katanga arc tectonic belt (also known as the Katanga belt) straddling the two countries of the Democratic Republic of the Congo and Zambia. This ore-forming belt is 325 km long and 50 km wide. It is the world's third largest copper ore-forming belt after the Andes in South America and the southwestern United States of America and Mexico in North America, and is also an important copper production base in the world. Currently, more than twenty kinds of copper and cobalt minerals have been discovered in production. The main copper minerals are malachite, followed by chalcocite, chrysocolla, tenorite, and a small amount of djurleite, phosphocopper, clinoclase, covellite, chalcopyrite, bornite, cuprite, native copper, etc.; the main cobalt minerals are hydrocobaltite and hydrocobaltite copper, followed by cobalt copper sulfide, cobalt dolomite, manganese cobalt copper hydrated oxide, etc. Other metal minerals include pyrite, limonite, hematite, and a small amount of rutile, etc. Among them, cobalt dolomite ore is a refractory copper and cobalt-containing metal ore, and the effect of recovering valuable copper and cobalt metals from it by various conventional beneficiation technologies such as flotation of sulfide ore - sulfide flotation of oxidized ore, flotation of sulfide ore - acid leaching of tailings is not ideal. Currently, the industry does not have a good treatment plan for cobalt dolomite. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the above-mentioned defects existing in the prior art and provide a method for neutralizing raffinate with cobalt dolomite containing low copper and simultaneously recovering copper and cobalt with good recovery effect.

[0004] The technical solution adopted by the present invention to solve its technical problems is as follows: A method for neutralizing raffinate with cobalt dolomite containing low copper and simultaneously recovering copper and cobalt, comprising:[[]]

[0005] Performing a neutralization reaction on the raw ore pulp of the cobalt dolomite and raffinate I to obtain a neutralized pulp; separating the solid and liquid of the neutralized pulp to obtain a neutralized feed liquid and a neutralized slag;

[0006] Mixing and leaching the neutralized slag with raffinate II to obtain a leaching pulp; separating the solid and liquid of the leaching pulp to obtain a leached feed liquid and a leached slag;

[0007] The copper grade of the cobalt dolomite is below 1.8 wt%; the oxidation rate of the cobalt dolomite is above 55 wt%;

[0008] The sulfuric acid content in raffinate I is above 8 g / L; the sulfuric acid content in raffinate II is above 8 g / L;

[0009] The iron content in raffinate II is above 1 g / L;

[0010] The leaching temperature for the mixed leaching of the neutralization residue and raffinate II is above 55°C.

[0011] Preferably, the copper grade of the cobalt dolomite is 0.8 wt% - 1.5 wt%.

[0012] Preferably, the cobalt grade of the cobalt dolomite is 0.3 wt% - 0.6 wt%.

[0013] Preferably, the oxidation rate of the cobalt dolomite is 60 wt% or more.

[0014] Preferably, the raw ore pulp is obtained by grinding the cobalt dolomite.

[0015] Preferably, the particle fineness of the raw ore pulp is such that the particle size content of -0.074 mm accounts for 75 wt% - 85 wt%.

[0016] Preferably, the concentration of the raw ore pulp is 50 wt% - 55 wt%.

[0017] Preferably, the weight ratio of the raw ore pulp used to raffinate I is 1:4 - 10.

[0018] Preferably, the neutralization reaction time of the raw ore pulp and raffinate I is 3 - 5 h.

[0019] Preferably, the raffinate I comes from a hydrometallurgical process for copper recovery.

[0020] Preferably, the copper content in the raffinate I is 1.5 - 2.5 g / L.

[0021] Preferably, the cobalt content in the raffinate I is 2.5 - 3.5 g / L.

[0022] Preferably, the iron content in the raffinate I is 2.5 - 3.5 g / L.

[0023] Preferably, the manganese content in the raffinate I is 0.5 - 1.0 g / L.

[0024] Preferably, the calcium content in the raffinate I is 0.5 - 0.8 g / L.

[0025] Preferably, the magnesium content in the raffinate I is 10 - 13 g / L.

[0026] Preferably, the aluminum content in the raffinate I is 1.5 - 2.0 g / L.

[0027] Preferably, the sulfuric acid content in the raffinate I is 15 - 25 g / L.

[0028] Preferably, the weight ratio of the neutralization residue used to raffinate II is 10 - 15:90 - 85.

[0029] Preferably, the leaching temperature for the mixed leaching of the neutralization residue and raffinate II is 70-80 °C.

[0030] Preferably, the leaching time for the mixed leaching of the neutralization residue and raffinate II is 3-5 h.

[0031] Preferably, the raffinate II is from a hydrometallurgical process for copper recovery.

[0032] Preferably, the raffinate II contains 1.5-2.5 g / L of copper.

[0033] Preferably, the raffinate II contains 2.5-3.5 g / L of cobalt.

[0034] Preferably, the raffinate II contains 2.5-3.5 g / L of iron.

[0035] Preferably, the raffinate II contains 0.5-1.0 g / L of manganese.

[0036] Preferably, the raffinate II contains 0.5-0.8 g / L of calcium.

[0037] Preferably, the raffinate II contains 10-13 g / L of magnesium.

[0038] Preferably, the raffinate II contains 1.5-2.0 g / L of aluminum.

[0039] Preferably, the sulfuric acid content in the raffinate II is 15-25 g / L.

[0040] Preferably, the method for neutralizing the raffinate with cobalt dolomite with low copper content and simultaneously recovering copper and cobalt further includes: performing iron and aluminum removal neutralization on the neutralized feed liquid and / or the leached feed liquid to obtain an iron and aluminum removal slurry; separating the solid and liquid of the iron and aluminum removal slurry to obtain an iron and aluminum removal post-liquid and an iron and aluminum slag.

[0041] More preferably, the neutralizing agent used for the iron and aluminum removal neutralization is lime.

[0042] Further preferably, the neutralizing agent used for the iron and aluminum removal neutralization is lime milk with a concentration of 9 wt% - 11 wt%.

[0043] More preferably, the neutralization end point of the iron and aluminum removal neutralization is that the pH value of the slurry is 3.8-4.2.

[0044] Preferably, the method for neutralizing the raffinate with cobalt dolomite with low copper content and simultaneously recovering copper and cobalt further includes: performing copper and cobalt precipitation neutralization on the iron and aluminum removal post-liquid to obtain a copper and cobalt precipitation slurry; separating the solid and liquid of the copper and cobalt precipitation slurry to obtain a copper and cobalt precipitation post-liquid and a copper and cobalt slag.

[0045] More preferably, the neutralizing agent used for the copper and cobalt precipitation neutralization is lime.

[0046] Further preferably, the neutralizing agent used for copper-cobalt precipitation and neutralization is lime milk with a concentration of 9 wt% to 11 wt%.

[0047] More preferably, the neutralization end point of copper-cobalt precipitation and neutralization is that the pulp pH value is 6.8 to 7.2.

[0048] The present invention has the following beneficial effects:

[0049] (1) The present invention uses cobalt dolomite with low copper content to replace lime to neutralize the residual acid in the raffinate that needs to be discharged from the system, greatly reducing the dosage of the neutralizing agent lime and reducing the amount of water generated during the neutralization process. While reducing the water expansion in the copper-cobalt metallurgical system, it also reduces the production cost;

[0050] (2) The present invention uses cobalt dolomite with low copper content to replace lime to neutralize the raffinate and recover valuable copper and cobalt metals in the cobalt dolomite. The direct grinding and leaching process is adopted, avoiding the flotation process with large equipment investment and high reagent consumption costs in the prior art, significantly saving costs, and at the same time avoiding the environmental pollution problems caused by the residues of reagents in the tailings due to the adoption of the flotation process;

[0051] (3) The present invention not only effectively utilizes the characteristic of high acid consumption of carbonate minerals in cobalt dolomite to neutralize the residual acid in the raffinate, but also utilizes the residual acid and the redox ions carried in the raffinate to recover valuable copper and cobalt metals in the cobalt dolomite; not only realizes the effective treatment of the raffinate, but also realizes the efficient leaching of valuable copper and cobalt metals in the cobalt dolomite. In the leaching stage of the neutralization residue, the copper and cobalt leaching rates are as high as over 97% and 92%;

[0052] (4) The present invention adopts the process of raffinate neutralization and warm leaching of the neutralization residue to treat cobalt dolomite with low copper content. No additional additives are required throughout the process. The reducibility of low-valent copper in the small amount of copper sulfide (chalcocite) contained in the cobalt dolomite itself and the oxidizability of high-valent cobalt are fully utilized. The self-oxidation-reduction reaction of the two under medium-temperature conditions enables copper and cobalt to be fully converted into ions and enter the solution, realizing their effective recovery;

[0053] (5) The treatment method of the raffinate provided by the present invention is an important part of the copper-cobalt hydrometallurgical system. By adopting the treatment method provided by the present invention, the raffinate that needs to be discharged from the system and the cobalt dolomite introduced into the system can be excluded from the system in multiple stages, greatly reducing the production pressure of the system; through the neutralization and leaching processes, the acidity of the raffinate that needs to be discharged from the system can be reduced from 15 - 25 g / L to 7 - 12 g / L, and the reduction range is between 50% - 54%; the mixed liquid of the subsequent neutralized liquid and leached liquid can be further used to remove iron and aluminum and precipitate copper and cobalt for neutralization by adding a small amount of neutralizing agent. When lime is used as the neutralizing agent, compared with the prior art of directly using lime to neutralize the raffinate, the lime dosage is reduced from 250 kg / m3 Reduce by 30 kg / m 3 , that is, the savings of lime exceed 80%.

[0054] In addition to the purposes, features and advantages described above, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0056] Figure 1 is a process flow schematic diagram of the method for neutralizing raffinate with copper-low cobalt dolomite and simultaneously recovering copper and cobalt in the preferred embodiment of the present invention;

[0057] Figure 2 is a photo of the ore of copper-low cobalt dolomite in Example 1 of the present invention;

[0058] Figure 3 is a process flow schematic diagram of the method for neutralizing raffinate with copper-low cobalt dolomite and simultaneously recovering copper and cobalt in Example 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0059] In order to make the purposes, solutions and beneficial technologies of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and the drawings. It should be noted that the embodiments described in this specification are only for explaining the present invention and not for limiting the present invention.

[0060] For simplicity, only some numerical ranges are explicitly disclosed herein. However, any lower limit can be combined with any upper limit to form a range not explicitly recorded; and any lower limit can be combined with other lower limits to form a range not explicitly recorded, and similarly any upper limit can be combined with any other upper limit to form a range not explicitly recorded. In addition, although not explicitly recorded, each point or single value between the range endpoints is included in this range. Thus, each point or single value can be used as its own lower limit or upper limit and combined with any other point or single value or combined with other lower limits or upper limits to form a range not explicitly recorded.

[0061] In the description herein, it should be noted that unless otherwise specified, "above" and "below" include this number, the meaning of "multiple" in "one or more" is two or more, and the meaning of "multiple" in "one or more" is two or more.

[0062] Such as Figure 1As shown in the process flow, an embodiment of the present invention provides a method for neutralizing raffinate with cobalt dolomite containing low copper and simultaneously recovering copper and cobalt, including:

[0063] The raw ore pulp of the cobalt dolomite reacts with raffinate I to obtain a neutralized pulp; the neutralized pulp is separated into a neutralized liquor and a neutralized residue by solid-liquid separation;

[0064] The neutralized residue is mixed and leached with raffinate II to obtain a leached pulp; the leached pulp is separated into a leached liquor and a leached residue by solid-liquid separation;

[0065] The copper grade of the cobalt dolomite is below 1.8 wt%; the oxidation rate of the cobalt dolomite is above 55 wt%;

[0066] The sulfuric acid content in raffinate I is above 8 g / L; the sulfuric acid content in raffinate II is above 8 g / L;

[0067] The iron content in raffinate II is above 1 g / L;

[0068] The leaching temperature for the mixing and leaching of the neutralized residue and raffinate II is above 55 °C.

[0069] The main copper and cobalt elements in the cobalt dolomite and raffinate I and raffinate II are extracted into the neutralized liquor and the leached liquor. After further impurity removal and / or purification treatment of the neutralized liquor and the leached liquor, enrichment of copper and cobalt elements can be achieved. The obtained leached residue is subjected to tailing discharge treatment.

[0070] The method for neutralizing raffinate with cobalt dolomite containing low copper and simultaneously recovering copper and cobalt provided by the embodiment of the present invention has the following advantages:

[0071] (1) Using cobalt dolomite with low copper content to replace lime to neutralize the residual acid in the raffinate that needs to be discharged out of the system, significantly reducing the dosage of the neutralizing agent lime and reducing the amount of water generated during the neutralization process. While reducing the water expansion in the copper and cobalt metallurgical system, it also reduces the production cost;

[0072] (2) Using cobalt dolomite with low copper content to replace lime to neutralize the raffinate and recover the valuable copper and cobalt metals in the cobalt dolomite, and adopting a direct grinding and leaching process, avoiding the flotation process with large equipment investment and high reagent consumption costs in the prior art, significantly saving costs, and at the same time avoiding the environmental pollution problem caused by the residue of reagents in the tailings due to the adoption of the flotation process;

[0073] (3) The high acid consumption of carbonate minerals in cobalt dolomite is effectively utilized to neutralize the residual acid in the raffinate, and the residual acid in the raffinate and the redox ions carried are utilized to recover the copper and cobalt valuable metals in the cobalt dolomite; the effective treatment of the raffinate is achieved, and the efficient leaching of copper and cobalt valuable metals in the cobalt dolomite is achieved. In the neutralization slag leaching stage, the copper and cobalt leaching rates are as high as 97% and 92% or more;

[0074] (4) The process of neutralizing the raffinate and heating the neutralized slag to leaching is used to treat the cobalt dolomite with low copper content. The whole process does not require any additional additives. The reducibility of low-valent copper in a small amount of copper sulfide (chalcocite) contained in the cobalt dolomite and the oxidizability of high-valent cobalt are fully utilized. The self-oxidation-reduction reaction of the two under medium temperature conditions fully converts copper and cobalt into ions and enters the solution, thereby achieving effective recovery of the two.

[0075] (5) The treatment method for raffinate provided in the embodiment of the present invention is an important part of the copper-cobalt hydrometallurgical system. By adopting the treatment method provided by the present invention, the raffinate to be discharged from the system and the cobalt dolomite introduced into the system can be discharged from the system in multiple stages, which greatly reduces the production pressure of the system; through the neutralization and leaching process, the acidity of the raffinate to be discharged from the system can be reduced from 15 to 25 g / L to 7 to 12 g / L, with a reduction of 50% to 54%; the mixed liquid of the subsequent neutralization liquid and the leaching liquid can be further neutralized by adding a small amount of neutralizing agent to remove iron and aluminum and precipitate copper and cobalt. When lime is used as the neutralizing agent, compared with the prior art of directly using lime to neutralize the raffinate, the amount of lime used is reduced from 250 kg / m 3 Reduce 30kg / m 3 , that is, the lime saving exceeds 80%.

[0076] In an embodiment of the present invention, the copper grade of the cobalt dolomite is 0.8wt% to 1.5wt%.

[0077] In an embodiment of the present invention, the cobalt grade of the cobalt dolomite is 0.3wt% to 0.6wt%.

[0078] In the embodiment of the present invention, the oxidation rate of the cobalt dolomite is above 60wt%. The oxidation rate refers to the proportion of copper and cobalt oxides in the ore.

[0079] In an embodiment of the present invention, the raw ore pulp is obtained by grinding the cobalt dolomite.

[0080] In an embodiment of the present invention, the raw ore slurry has a particle size of -0.074 mm, and the content of the particle size is 75 wt% to 85 wt%.

[0081] In an embodiment of the present invention, the concentration of the raw ore pulp is 50 wt% to 55 wt%. The concentration of the raw ore pulp can be controlled during the grinding process, and the pulp with the corresponding concentration can be directly obtained after grinding; or it can be concentrated or diluted according to the pulp concentration after grinding to make the concentration meet the requirements. The recycled water obtained by concentration can be returned to the grinding process for use.

[0082] In an embodiment of the present invention, the weight ratio of the raw ore pulp to raffinate I is 1:4 to 10.

[0083] In some embodiments of the present invention, the concentration of the pulp after mixing the raw ore pulp and raffinate I is 5 wt% to 10 wt%.

[0084] In an embodiment of the present invention, the neutralization reaction time of the raw ore pulp and raffinate I is 3 to 5 h.

[0085] The neutralization reaction of the raw ore pulp and raffinate I has no strict limitation on the reaction temperature and can be carried out at a general ambient temperature.

[0086] In an embodiment of the present invention, the raffinate I comes from a hydrometallurgical process for recovering copper.

[0087] In an embodiment of the present invention, the raffinate I is the raffinate obtained after treating a copper sulfate-cobalt feed liquid by an extraction process in a hydrometallurgical system.

[0088] In some embodiments of the present invention, the copper content in the raffinate I is 1.5 to 2.5 g / L. For the raffinate obtained after treating a copper sulfate-cobalt feed liquid by a general extraction process in a hydrometallurgical system, the element content conforms to this range.

[0089] In some embodiments of the present invention, the cobalt content in the raffinate I is 2.5 to 3.5 g / L. For the raffinate obtained after treating a copper sulfate-cobalt feed liquid by a general extraction process in a hydrometallurgical system, the element content conforms to this range.

[0090] In some embodiments of the present invention, the iron content in the raffinate I is 2.5 to 3.5 g / L. For the raffinate obtained after treating a copper sulfate-cobalt feed liquid by a general extraction process in a hydrometallurgical system, the element content conforms to this range.

[0091] In some embodiments of the present invention, the manganese content in the raffinate I is 0.5 to 1.0 g / L. For the raffinate obtained after treating a copper sulfate-cobalt feed liquid by a general extraction process in a hydrometallurgical system, the element content conforms to this range.

[0092] In some embodiments of the present invention, the calcium content in the raffinate I is 0.5 to 0.8 g / L. For the raffinate obtained after treating a copper sulfate-cobalt feed liquid by a general extraction process in a hydrometallurgical system, the element content conforms to this range.

[0093] In some embodiments of the present invention, the raffinate I contains 10 - 13 g / L of magnesium. The elemental content of the raffinate obtained by treating copper sulfate - cobalt feed liquid through the extraction process of a general hydrometallurgical system conforms to this range.

[0094] In some embodiments of the present invention, the raffinate I contains 1.5 - 2.0 g / L of aluminum. The elemental content of the raffinate obtained by treating copper sulfate - cobalt feed liquid through the extraction process of a general hydrometallurgical system conforms to this range.

[0095] In some embodiments of the present invention, the sulfuric acid content in the raffinate I is 15 - 25 g / L. The sulfuric acid in the raffinate I reacts with the copper minerals and gangue minerals in the ore that are easily soluble in acid.

[0096] In the embodiments of the present invention, the weight ratio of the neutralization residue to the raffinate II is 10 - 15∶90 - 85. It is equivalent to that after the neutralization residue and the raffinate II are mixed, the pulp concentration is 10wt% - 15wt%.

[0097] In the embodiments of the present invention, the leaching temperature for the mixed leaching of the neutralization residue and the raffinate II is 70 - 80 °C.

[0098] In the embodiments of the present invention, the leaching time for the mixed leaching of the neutralization residue and the raffinate II is 3 - 5 h.

[0099] Leaching can be carried out under medium - temperature conditions. Compared with operation processes such as high - temperature roasting, oxygen - pressure leaching, and reduction leaching, while saving energy and environmental protection investment, the process operation safety is almost no different from that of conventional sulfuric acid leaching.

[0100] In the embodiments of the present invention, the raffinate II comes from a hydrometallurgical process for copper recovery.

[0101] In the embodiments of the present invention, the raffinate II is the raffinate obtained by treating copper sulfate - cobalt feed liquid through the extraction process of a hydrometallurgical system.

[0102] In some embodiments of the present invention, the raffinate II contains 1.5 - 2.5 g / L of copper. The elemental content of the raffinate obtained by treating copper sulfate - cobalt feed liquid through the extraction process of a general hydrometallurgical system conforms to this range.

[0103] In some embodiments of the present invention, the raffinate II contains 2.5 - 3.5 g / L of cobalt. The elemental content of the raffinate obtained by treating copper sulfate - cobalt feed liquid through the extraction process of a general hydrometallurgical system conforms to this range.

[0104] In some embodiments of the present invention, the raffinate II contains 2.5 - 3.5 g / L of iron. The iron element in the raffinate II not only has its own oxidizing / reducing property, but also promotes the redox reaction as a reaction medium. For the raffinate obtained by the extraction process of a general hydrometallurgical system treating a copper sulfate-cobalt feed solution, the element content conforms to this range; when the iron content is higher, the leaching effect is better, but generally the iron content in the obtained raffinate will not be so high; experimental studies show that when the iron content in the raffinate is lower, the leaching effect will decrease slightly, but when it reaches above 1 g / L, the overall impact is not significant.

[0105] In some embodiments of the present invention, the raffinate II contains 0.5 - 1.0 g / L of manganese. For the raffinate obtained by the extraction process of a general hydrometallurgical system treating a copper sulfate-cobalt feed solution, the element content conforms to this range.

[0106] In some embodiments of the present invention, the raffinate II contains 0.5 - 0.8 g / L of calcium. For the raffinate obtained by the extraction process of a general hydrometallurgical system treating a copper sulfate-cobalt feed solution, the element content conforms to this range.

[0107] In some embodiments of the present invention, the raffinate II contains 10 - 13 g / L of magnesium. For the raffinate obtained by the extraction process of a general hydrometallurgical system treating a copper sulfate-cobalt feed solution, the element content conforms to this range.

[0108] In some embodiments of the present invention, the raffinate II contains 1.5 - 2.0 g / L of aluminum. For the raffinate obtained by the extraction process of a general hydrometallurgical system treating a copper sulfate-cobalt feed solution, the element content conforms to this range.

[0109] In some embodiments of the present invention, the sulfuric acid content in the raffinate II is 15 - 25 g / L. The raffinate II provides an acidic environment to promote leaching.

[0110] In some embodiments of the present invention, the method of neutralizing the raffinate with cobalt dolomite with low copper content and simultaneously recovering copper and cobalt further includes: performing iron and aluminum removal neutralization on the neutralized feed solution and / or the leached feed solution to obtain an iron and aluminum removal slurry; separating the solid and liquid of the iron and aluminum removal slurry to obtain a post-iron and aluminum removal solution and an iron and aluminum slag. The obtained iron and aluminum slag is subjected to tailing disposal, and the impurities in the raffinate and cobalt dolomite entering the system are discharged from the system in segments, greatly reducing the production pressure of the system.

[0111] In some embodiments of the present invention, the neutralizing agent used for the iron and aluminum removal neutralization is lime. Only a small amount of lime neutralization is required to discharge the impurities from the system, reducing the impurity content of the entire system and improving the product quality.

[0112] In some embodiments of the present invention, the neutralizing agent used for iron and aluminum removal and neutralization is lime milk with a concentration of 9 wt% to 11 wt%. Adding lime in the form of lime milk has a higher dispersion efficiency and the neutralization reaction occurs more evenly.

[0113] In some embodiments of the present invention, the neutralization end point of the iron and aluminum removal and neutralization is that the pH value of the pulp is 3.8 to 4.2.

[0114] In some embodiments of the present invention, the method of neutralizing the raffinate with cobalt dolomite with low copper content and simultaneously recovering copper and cobalt further includes: subjecting the solution after iron and aluminum removal to copper and cobalt precipitation and neutralization to obtain a copper and cobalt precipitation pulp; separating the solid and liquid of the copper and cobalt precipitation pulp to obtain a solution after copper and cobalt precipitation and a copper and cobalt slag. The obtained solution after copper and cobalt precipitation is subjected to tailings discharge treatment, and impurities in the incoming raffinate and cobalt dolomite are discharged from the system in stages, greatly reducing the production pressure of the system. The copper and cobalt grades in the obtained copper and cobalt slag are both about 5 wt% to 6 wt%, and can enter the leaching system for redissolution to recover valuable metals of copper and cobalt.

[0115] In some embodiments of the present invention, the neutralizing agent used for copper and cobalt precipitation and neutralization is lime. Only a small amount of lime neutralization is required to discharge impurities from the system, reducing the impurity content of the entire system and improving the product quality.

[0116] In some embodiments of the present invention, the neutralizing agent used for copper and cobalt precipitation and neutralization is lime milk with a concentration of 9 wt% to 11 wt%. Adding lime in the form of lime milk has a higher dispersion efficiency and the neutralization reaction occurs more evenly.

[0117] In some embodiments of the present invention, the neutralization end point of the copper and cobalt precipitation and neutralization is that the pH value of the pulp is 6.8 to 7.2.

[0118] The cobalt dolomite ore involved in the present invention is a refractory copper-cobalt-bearing metal ore. The effects of recovering valuable copper and cobalt metals from it using various conventional beneficiation techniques are not ideal, and there is currently no good treatment solution for cobalt dolomite in the industry. In addition to cobalt dolomite ore, various low-grade cobalt ores are also often involved in the field of ore recovery, such as copper-cobalt ore flotation tailings, other low-grade copper-cobalt oxide ore raw ores, mineralized waste rocks, etc. Copper-cobalt ore flotation tailings refer to the products in the beneficiation separation operation with relatively low copper and cobalt component contents and cannot be used for production and are stored in the tailings pond. Under the existing technical conditions in the industry, they do not have great recycling value; Mineralized waste rocks refer to the solid materials generated during the mining process, with copper and cobalt grades lower than the industrial grade and not entering subsequent operations such as beneficiation. They have certain recycling value, but are temporarily stored unused due to high production and treatment costs. The main problems encountered in the recovery of these low-grade cobalt ores are: due to the low content of valuable metals, the average processing cost per ton of product is high, while the beneficiation difficulty itself is not very large. The grades of cobalt dolomite ore vary, and generally, due to the difficulty of obtaining good recovery effects with existing production processes, they are temporarily stored. For the copper-cobalt ore in the northwest part of the Central African ore belt, due to the control of the ore deposit by strata and structures, the influence of external hydrothermal and weathering effects, on the one hand, the oxidation degree is relatively high and the composition of valuable minerals is complex; on the other hand, a large amount of wall rock alteration is induced, mainly silicification, carbonatization, and talcification, belonging to high-carbonate gangue-type oxidized ore, and the smelting and recovery are difficult.

[0119] Currently, in enterprises in the Democratic Republic of the Congo that use hydrometallurgical processes to recover copper and cobalt metals, to ensure the quality of copper and cobalt products, a part of the liquid must be regularly discharged from the system during the production process to reduce the content of impurity ions in the system and relieve the water swelling pressure of the system, generally in the form of raffinate. The raffinate discharged from the system, in addition to containing a large amount of impurity metal ions in the liquid, also contains a certain amount of sulfuric acid. If directly discharged, it will inevitably cause serious environmental pollution problems. The traditional method for treating raffinate is to neutralize it by adding lime to make it meet the discharge standard. Due to the impurity ions and sulfuric acid contained in the raffinate, a large amount of lime is often required during the production process to reach the discharge standard. This results in an increase in production costs.

[0120] In the embodiment of the present invention, cobalt dolomite with low copper content is used to replace lime as the neutralizing agent for raffinate, solving the problem of resource waste caused by the difficulty of recovering copper and cobalt metals in low-copper cobalt dolomite in existing process technologies. At the same time, it fundamentally solves the problems of high cost and high investment when using lime to neutralize raffinate. The comprehensive copper and cobalt recovery rates of the whole process are above 84% and 90% respectively.

[0121] During the neutralization reaction of the raw ore pulp and raffinate I in the embodiments of the present invention, the main reactions that carbonate gangue minerals and other gangue minerals existing in cobalt dolomite with low copper content react with sulfuric acid in the raffinate are shown in formulas (1) to (5):

[0122] CaCO 3 + H 2 SO 4 = CaSO 4 + H 2 O + CO 2 ↑ (1)

[0123] MgCO 3 + H 2 SO 4 = MgSO 4 + H 2 O + CO 2 ↑ (2)

[0124] CoCO 3 + H 2 SO 4 = CoSO 4 + H 2 O + CO 2 ↑ (3)

[0125] MnCO 3 + H 2 SO 4 = MnSO 4 + H 2 O + CO 2 ↑ (4)

[0126] A1 2 O 3 +3H 2 SO 4 → A1 2 (SO) 4 + 3H 2 O (5)

[0127] Meanwhile, copper minerals such as malachite, chrysocolla, and phosphocopper existing in cobalt dolomite, which are easily soluble in sulfuric acid at room temperature, also react with sulfuric acid in the raffinate, as shown in formulas (6) to (8):

[0128] CuCO 3 · Cu(OH) 2 +2H 2 SO 4 → 2CuSO 4 + 3H 2O + 2CO 2 ↑ (6)

[0129] CuSiO 3· 2H 2 O + H 2 SO 4 → CuSO 4 + SiO 2 +3H 2 O (7)

[0130] Cu 2 (PO 4 )OH + 2H 2 SO 4 → 2CuSO 4 + H 2 O + H 3 PO 4 (8)

[0131] After the above neutralization process, the copper minerals and gangue minerals in the ore that are easily soluble in acid have basically reacted completely with the sulfuric acid in the raffinate, while the copper sulfide-cobalt minerals and higher-valent cobalt oxides that are insoluble in sulfuric acid at room temperature still exist in the neutralization residue in solid form. These copper compounds are mainly chalcocite (4Cu 2 S·CuS), covellite (CuS), bornite (Cu 5 FeS 4 ), and carrollite (CuCo 2 S 4 ), and the cobalt compounds are mainly cobalt compounds of Co 3+ .

[0132] Copper in sulfide state and trivalent cobalt compounds are insoluble in acid at room temperature. However, during the heating process of leaching the neutralization residue with raffinate II, with the addition of raffinate again and the increase in the temperature of the reaction system, these compounds will still undergo weak ionization in the presence of H + and transfer into the solution in ionic form. There is a certain amount of Fe 2+ and Fe 3+ in the raffinate. Fe 2+ has reducibility, and under heating conditions, H + will accelerate the redox reaction and can directly reduce Co 3+ to Co 2+ while generating goethite. The generated FeOOH then continues to react with H 2 SO 4 . The reaction equations are shown in Equations (9) and (10):

[0133] Co(OH) 3 + Fe2+ = Co 2+ + FeOOH + H 2 O (9)

[0134] 2FeOOH + 6H + → 2Fe 3+ + 4H 2 O (10)

[0135] During the heating leaching process, as the redox reaction proceeds, the oxidized ores and sulfide ores existing in the form of inclusions and aggregates combined with the oxidized ores are gradually dissociated and exposed in the solution; these sulfide ores are mainly chalcocite (CuS) and cobalt copper sulfide (CuCo 2 S 4 ), and the sulfides of these sulfide ores exposed in the solution are oxidized by Fe 3+ , Co 3+ in the solution to generate S, Cu 2+ , Fe 3+ , Co 3+ itself is reduced to Fe 2+ , Co 2+ . The overall reactions are shown in equations (11) and (12):

[0136] 2CuS + 4H + + Fe 3+ = 2Cu 2+ + 2S + Fe 2+ (11)

[0137] 2CuS + 4H + + Co 3+ = 2Cu 2+ + 2S + Co 2+ (12)

[0138] The ionization equilibria of CuS and CuCo 2 S 4 in the solution are shown in equations (13) and (14):

[0139] CuS = Cu 2+ + S 2－ (13)

[0140] CuCo 2 S 4 = Cu 2+ + 2Co 3+ + 4S 2－ (14)

[0141] In an acidic environment, the ionized S 2－The ions are converted into hydrosulfuric acid by the sulfuric acid in the system, as shown in formula (15):

[0142] S 2－ + 2H + = H 2 S (15)

[0143] Hydrogen sulfide is a weak acid. In acidic solution, 2－ Almost all of it exists in the form of hydrosulfuric acid. At the same time, hydrosulfuric acid is absorbed by the Co in the solution. 3+ , Fe 3+ Oxidation of elemental sulfur, see formula (16), (17):

[0144] H 2 S + 2Co 3+ → 2H + + S↓+ 2 Co 2+ (16)

[0145] H 2 S + 2Fe 3+ → 2H + + S↓+ 2 Fe 2+ (17)

[0146] The generated elemental sulfur is very likely to appear in the form of colloids, because sulfur colloids can absorb hydrogen sulfide ions HS in the solution － The negative charge, coupled with the adsorption of the micelle itself, causes a considerable amount of Fe to be adsorbed on the surface of the sulfur micelle. 2+ Ion, Fe 2+ The O dissolved in the solution during stirring 2 The reaction generates Fe 3+ , see formula (18):

[0147] 4Fe 2+ + 4H + + O 2 → 4Fe 3+ + 2H 2 O (18)

[0148] Fe 3+ Continue to oxidize elemental S to HSO 3 － , H 2 SO 3 and a small amount of SO 3 2－ , see formula (19):

[0149] S + 4Fe 3+ + 3H 2 O → H 2 SO 3+ 4Fe 2+ + 4H + (19)

[0150] H 2 SO 3 reacts with the dissolved O 2 to generate SO 4 2－ , as shown in Equation (20):

[0151] 2H 2 SO 3 + O 2 → 2SO 4 2－ + 4H + (20)

[0152] The above reactions continue until all the CuS, CuCo 2 S 4 , CoO(OH) x and other substances in the solution have completely reacted.

[0153] In the iron and aluminum neutralization of some embodiments of the present invention, OH - has obvious selectivity for iron and aluminum (Ksp(Fe(OH) 3 ) = 1.1*10 -36 , Ksp(Al(OH) 2 ) = 3.0*10 -34 , Ksp(Al(OH) 3 ) = 3.0*10 -34 ), and can preferentially react with iron and aluminum to precipitate as iron hydroxide and aluminum hydroxide. In the pH range of 3.8 - 4.2, the main reactions of the ions in the solution are as follows, as shown in Equations (21) - (24):

[0154] Fe 2+ + 2OH - = Fe(OH) 2 ↓ (21)

[0155] Fe 3+ + 3OH - = Fe(OH) 3 ↓ (22)

[0156] Al 3+ + 2OH - = Al 2 (OH) 4 ↓ (23)

[0157] 2H + + OH -= H 2 O (24)

[0158] In some embodiments of the present invention, when copper and cobalt are precipitated and the solution is neutralized after solid-liquid separation and iron and aluminum removal from the post-liquid, as the pH of the solution increases, when the pH of the solution increases to 6.8 - 7.2, a large amount of Cu 2+ , Co 2+ in the solution react with OH - to form copper hydroxide and cobalt hydroxide precipitates, which enter the precipitate residue and become the finally recoverable copper-cobalt slag. The main reactions are shown in equations (25) and (26).

[0159] Cu 2+ + 2OH - = Cu(OH) 2 ↓ (25)

[0160] Co 2+ + 3OH - = Co(OH) 2 ↓ (26)

[0161] Example

[0162] The following examples more specifically describe the content disclosed in the present invention. These examples are only for illustrative purposes, because various modifications and changes within the scope of the present invention are obvious to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are based on weight. Unless otherwise stated, all reagents used in the examples can be obtained through conventional commercial channels or synthesized according to conventional methods and can be used directly without further treatment. Unless otherwise stated, the instruments used in the examples can be obtained through conventional commercial channels.

[0163] Example 1

[0164] A copper-cobalt hydrometallurgy production enterprise in the Democratic Republic of the Congo needs to open a circuit for the raffinate solution out of the system, which contains 1.55 g / L of copper, 2.53 g / L of cobalt, 2.75 g / L of iron, 0.59 g / L of manganese, 0.58 g / L of calcium, 11.13 g / L of magnesium, 1.52 g / L of aluminum, and the residual sulfuric acid content is 15.25 g / L; in this example, cobalt dolomite with low copper content is used to neutralize the raffinate solution and recover copper and cobalt synchronously; the copper grade of the cobalt dolomite is 0.88%, the cobalt grade is 0.376%, and the oxidation rate is 63.58%. The typical appearance of the cobalt dolomite with low copper content in this example is as Figure 2 shown.

[0165] As Figure 3 shown in the process flow, the method for neutralizing the raffinate solution with cobalt dolomite with low copper content and recovering copper and cobalt synchronously in this example is carried out according to the following steps:

[0166] (1) Grind the cobalt dolomite, and the grinding water is fresh water and the concentrated return water of the pulp after grinding; obtain a pulp with a fineness of -0.074mm particle size accounting for 79.13% and a pulp concentration of 33.35%, and concentrate it to a pulp concentration of 54.47%.

[0167] (2) Add the raffinate to the obtained pulp until the pulp concentration is diluted to 7.5%; carry out a neutralization reaction at room temperature, separate the solid and liquid after neutralization for 4 hours to obtain a neutralized feed liquid and neutralized slag.

[0168] (3) Add the raffinate to the neutralized slag until the pulp concentration is 14.47%, leach at 78°C for 4 hours, separate the solid and liquid of the obtained leaching pulp to obtain a leached feed liquid and leached slag, and wash the leached slag for tailings disposal.

[0169] (4) After the obtained leached feed liquid and neutralized feed liquid are combined, slowly add 10% lime milk for iron and aluminum removal and neutralization. Stop adding lime milk when the pH value of the pulp is 3.84, separate the solid and liquid to obtain a liquid after iron and aluminum removal and iron and aluminum slag, and carry out tailings disposal on the iron and aluminum slag.

[0170] (5) Slowly add 10% lime milk to the liquid after iron and aluminum removal for copper and cobalt precipitation and neutralization. Stop adding lime milk when the pH value of the pulp is 6.87, separate the solid and liquid to obtain a liquid after copper and cobalt precipitation and copper and cobalt slag; carry out tailings disposal on the liquid after copper and cobalt precipitation; the copper and cobalt slag is the product finally obtained in this example and can enter the leaching system for redissolution to recover valuable copper and cobalt metals.

[0171] Using the method of this example, cobalt dolomite with low copper content is used to neutralize the raffinate. For every 1 m 3 The raffinate can simultaneously consume and process 361 kg of cobalt dolomite ore with low copper content, and in the processes of room temperature neutralization and heating leaching of the raffinate, the leaching rates of copper and cobalt are 97.93% and 92.08% respectively; after the processes of iron and aluminum removal and neutralization and copper and cobalt precipitation and neutralization, the comprehensive recovery rates of copper and cobalt in the final raffinate and cobalt dolomite are 84.56% and 90.12% respectively, and the lime consumption is 70.54 kg (lime) / m 3 (raffinate). Compared with directly using lime to neutralize the raffinate, under the same conditions, the lime consumption is reduced by 179.46 kg (lime) / m 3 (raffinate).

[0172] Example 2

[0173] A copper-cobalt hydrometallurgical production enterprise in the Democratic Republic of the Congo needs to discharge the raffinate from the system, which contains 1.82 g / L of copper, 2.98 g / L of cobalt, 2.95 g / L of iron, 0.72 g / L of manganese, 0.73 g / L of calcium, 12.03 g / L of magnesium, 1.69 g / L of aluminum, and the residual sulfuric acid content is 20.78 g / L. In this example, cobalt dolomite with low copper content is used to neutralize the raffinate and recover copper and cobalt simultaneously. The copper grade of the cobalt dolomite is 1.12%, the cobalt grade is 0.503%, and the oxidation rate is 79.14%.

[0174] The method for neutralizing the raffinate with cobalt dolomite with low copper content and recovering copper and cobalt simultaneously in this example is carried out according to the following steps:

[0175] (1) Grind the cobalt dolomite. The grinding water is fresh water and the concentrated return water of the pulp after grinding. The fineness of the grinding product is that the particle size of -0.074 mm accounts for 77.78%, and the pulp concentration is 33.35%. It is concentrated to a pulp concentration of 52.17%.

[0176] (2) Add the raffinate to the obtained pulp until the pulp concentration is diluted to 7.69%. Carry out the neutralization reaction at room temperature. After neutralization for 4 h, carry out solid-liquid separation to obtain the neutralized feed liquid and the neutralized slag.

[0177] (3) Add the raffinate to the neutralized slag until the pulp concentration is 12.5%. Leach at 75 °C for 4 h. Carry out solid-liquid separation on the obtained leaching pulp to obtain the leached feed liquid and the leached slag. The leached slag is washed and then discharged for tailings treatment.

[0178] (4) After the obtained leached feed liquid and the neutralized feed liquid are combined, slowly add 10% lime milk for iron and aluminum removal and neutralization. Stop adding lime milk when the pH value of the pulp is 3.87. Carry out solid-liquid separation to obtain the liquid after iron and aluminum removal and the iron and aluminum slag. The iron and aluminum slag is discharged for tailings treatment.

[0179] (5) Slowly add 10% lime milk to the liquid after iron and aluminum removal for copper and cobalt precipitation and neutralization. Stop adding lime milk when the pH value of the pulp is 6.85. Carry out solid-liquid separation to obtain the liquid after copper and cobalt precipitation and the copper and cobalt slag. The liquid after copper and cobalt precipitation is discharged for tailings treatment. The copper and cobalt slag is the final product obtained in this example and can enter the leaching system for back dissolution to recover valuable copper and cobalt metals.

[0180] Using the method of this example, cobalt dolomite with low copper content is used to neutralize the raffinate. For every 1 m 3The raffinate can simultaneously consume and process 358 kg of cobalt dolomite ore with low copper content. During the normal-temperature neutralization and heating leaching processes of the raffinate, the leaching rates of copper and cobalt are 97.96% and 92.48% respectively. After the iron and aluminum removal neutralization and copper and cobalt precipitation neutralization processes, the comprehensive recovery rates of copper and cobalt in the final raffinate and cobalt dolomite are 85.01% and 90.47% respectively, and the lime consumption is 77.63 kg (lime) / m 3 (raffinate). Compared with directly neutralizing the raffinate with lime, under the same conditions, the lime consumption is reduced by 172.37 kg (lime) / m 3 (raffinate).

[0181] Example 3

[0182] For a copper-cobalt hydrometallurgy production enterprise in the Democratic Republic of the Congo, the raffinate to be discharged from the system contains 2.10 g / L of copper, 3.27 g / L of cobalt, 3.29 g / L of iron, 0.99 g / L of manganese, 0.79 g / L of calcium, 12.6 g / L of magnesium, 1.78 g / L of aluminum, and the residual sulfuric acid content is 23.23 g / L; in this example, cobalt dolomite with low copper content is used to neutralize the raffinate and simultaneously recover copper and cobalt; the copper grade of the cobalt dolomite is 1.27%, the cobalt grade is 0.597%, and the oxidation rate is 90.04%.

[0183] The method for neutralizing the raffinate with cobalt dolomite with low copper content and simultaneously recovering copper and cobalt in this example is carried out according to the following steps:

[0184] (1) Grind the cobalt dolomite, and the grinding water is fresh water and the concentrated return water of the ore pulp after grinding; obtain an ore pulp with a grinding product fineness of -0.074 mm particle size fraction accounting for 75.01% and a pulp concentration of 33.35%, and concentrate it to a pulp concentration of 50.10%.

[0185] (2) Add the raffinate to the obtained ore pulp until the pulp concentration is diluted to 6.67%; carry out a neutralization reaction at normal temperature, separate the solid and liquid after neutralization for 4 h, and obtain a neutralized feed liquid and a neutralized residue.

[0186] (3) Add the raffinate to the neutralized residue until the pulp concentration is 12.5%, leach at 75 °C for 4 h, carry out solid-liquid separation on the obtained leaching pulp, obtain a leached feed liquid and a leached residue, and wash and discharge the leached residue for tailings treatment.

[0187] (4) After the obtained leached feed liquid and the neutralized feed liquid are combined, slowly add 10% lime milk for iron and aluminum removal neutralization, stop adding lime milk when the pulp pH value is 4.02, carry out solid-liquid separation to obtain a liquid after iron and aluminum removal and an iron and aluminum slag, and carry out tailings treatment on the iron and aluminum slag.

[0188] (5) Slowly add lime milk with a concentration of 10% to the solution after iron and aluminum removal for copper and cobalt precipitation and neutralization. Stop adding lime milk when the pulp pH value reaches 7.01. After solid-liquid separation, obtain the solution after copper and cobalt precipitation and copper-cobalt slag; the solution after copper and cobalt precipitation is discharged for tailing treatment; the copper-cobalt slag is the final product obtained in this example and can enter the leaching system for redissolution to recover valuable copper and cobalt metals.

[0189] Using the method of this example, cobalt dolomite with low copper content is used to neutralize the raffinate. For every 1 m 3 The raffinate can consume 355 kg of cobalt dolomite ore with low copper content for treatment at the same time. And in the processes of normal-temperature neutralization and heating leaching of the raffinate, the leaching rates of copper and cobalt are 97.68% and 92.79% respectively. After the processes of iron and aluminum removal neutralization and copper and cobalt precipitation neutralization, the comprehensive recovery rates of copper and cobalt in the final raffinate and cobalt dolomite are 85.67% and 91.05% respectively, and the lime consumption is 76.82 kg (lime) / m 3 (raffinate). Compared with directly using lime to neutralize the raffinate, under the same conditions, the lime consumption is reduced by 173.18 kg (lime) / m 3 (raffinate).

[0190] Comparative Example 1

[0191] For other low-grade mixed copper-cobalt ores, the existing main treatment method in the industry is to first float the copper-cobalt sulfide ore, and then perform sulfide flotation on the obtained flotation tailings for copper-cobalt oxide. The specific process is as follows: First, use the most common xanthate collectors (butyl xanthate or amyl xanthate) for sulfide ore flotation, and the dosage is usually controlled between 100 and 300 g / t for the total dosage in roughing and scavenging according to the ore grade; after sulfide ore flotation, the obtained flotation tailings are sulfided with a sulfiding agent for the copper-cobalt oxide ore in the tailings, and then the copper-cobalt oxide is floated. The commonly used sulfiding agents are sodium sulfide and sodium hydrosulfide. The process of sulfide flotation of copper-cobalt oxide ore is usually controlled at 1 - 7 stages of oxide ore flotation according to the grade and oxidation rate of the copper-cobalt oxide in the ore. The total dosage of the sulfiding agent for 1 - 7 stages of oxide ore flotation is usually controlled between 5 and 8 kg / t according to the different oxidation rates of the ore. The collector used for sulfide flotation of oxide ore is the common xanthate collector (butyl xanthate or amyl xanthate), and the total dosage is between 300 and 400 g / t; the foaming agent used in the processes of copper-cobalt sulfide ore flotation and copper-cobalt oxide ore flotation is No. 2 oil, and the total dosage is between 80 and 120 g / t. Using this method to treat the cobalt dolomite samples in Example 1, Example 2, and Example 3, the beneficiation indexes are shown in Table 1:

[0192] Table 1 Beneficiation indexes of direct flotation of sulfide ore - sulfide flotation of oxide ore for cobalt dolomite

[0193]

[0194] As can be seen from Table 1, for the original ore samples in Examples 1, 2, and 3 processed by the conventional beneficiation process of directly flotation of sulfide ores - sulfide flotation of oxidized ores, the total copper recoveries are 62.69%, 59.77%, and 60.21% respectively. Compared with the copper leaching rates (copper recoveries) of 97.93%, 97.96%, and 97.68% in the leaching stage of Examples 1, 2, and 3, they are respectively 35.24%, 38.19%, and 37.47% lower; in Comparative Example 1, the total cobalt recoveries are 43.29%, 32.19%, and 33.24% respectively. Compared with the cobalt leaching rates (cobalt recoveries) of 92.08%, 92.48%, and 92.79% in the leaching stage of Examples 1, 2, and 3, they are respectively 48.79%, 60.29%, and 59.55% lower. It can be seen that if the cobalt dolomite is processed by the conventional process of first directly flotation of copper - cobalt sulfide ore - sulfide flotation tailings and then sulfide flotation of copper - cobalt oxide, the recovery effect of copper and cobalt is poor.

[0195] Comparative Example 2

[0196] For other low - grade mixed copper - cobalt ores, another main existing treatment method in the industry is: flotation of copper - cobalt sulfide ore - sulfuric acid leaching process of sulfide flotation tailings. The sulfuric acid leaching process usually has a pulp mass liquid - solid ratio of 6:1, a leaching time of 4h. During the leaching process, the pulp pH is controlled within the range of 1.5 ± 0.01 by directly adding 98% concentrated sulfuric acid. After the leaching is completed, the pulp is filtered. The residual acid concentration in the filtrate is measured by acid - base neutralization titration method. The copper and cobalt element contents in the filter residue are determined by ICP method after washing and drying. According to the analysis and detection results, the acid consumption and the corresponding leaching rate are calculated. Using this process to process the cobalt dolomite samples in Examples 1, 2, and 3 of the present invention, the beneficiation indexes are shown in Table 2:

[0197] Table 2 Indexes of direct flotation of sulfide ore - tailings acid leaching of cobalt dolomite

[0198]

[0199] As can be seen from Table 2, when the conventional process of flotation of copper-cobalt sulfide ore - sulfuric acid leaching of flotation tailings of sulfide ore is used to treat the original ore samples, the total copper recovery rates are 87.50%, 89.35% and 89.59% respectively, which are 10.43%, 8.61% and 8.09% lower than the copper leaching rates (copper recovery rates) of 97.93%, 97.96% and 97.68% in Example 1, Example 2 and Example 3 respectively; in Comparative Example 2, the total cobalt recovery rates are 77.18%, 80.91% and 78.44% respectively, which are 14.90%, 11.57% and 14.35% lower than the cobalt leaching rates (cobalt recovery rates) of 92.08%, 92.48% and 92.79% in the leaching stage of Example 1, Example 2 and Example 3 respectively. It can be seen that if the cobalt dolomite sample is treated by the process of flotation of copper-cobalt sulfide ore - sulfuric acid leaching of flotation tailings of sulfide ore, the recovery effect of copper and cobalt is poor.

[0200] Comparative Example 3

[0201] In this comparative example, acid leaching tests were carried out on the cobalt dolomite samples in Example 1, Example 2 and Example 3 and other copper-cobalt ores with similar grades. The test conditions were that the mass liquid-solid ratio of the pulp was 6:1, the leaching time was 4 h, the pH of the pulp was controlled within the range of 1.5±0.01 by directly adding 98% concentrated sulfuric acid during the leaching process. After the leaching was completed, the pulp was filtered, the residual acid concentration in the filtrate was measured by acid-base neutralization titration, and the elemental contents of copper and cobalt in the filter residue were determined by ICP method after washing and drying. According to the analysis and detection results, the acid consumption and the corresponding leaching rate were calculated and statistically analyzed, from which the treatment difficulty of the ore could be reflected. The results are shown in Table 3. Among them, the 1#, 2# and 3# copper-cobalt ores of the copper-cobalt ore involved are all copper-cobalt ores without cobalt dolomite from the open-pit mining pit of a certain mining area in Lualaba Province, Democratic Republic of the Congo. The 1#, 2# and 3# copper-cobalt ores are respectively close to the copper and cobalt grades of the cobalt dolomite in Example 1, Example 2 and Example 3, the oxidation rates are close, and the main component of the sulfide ore is chalcocite.

[0202] Table 3 Comparative analysis of acid consumption differences between cobalt dolomite copper-cobalt ore and other copper-cobalt ores

[0203]

[0204] As can be seen from Table 3, compared with other ores with similar copper and cobalt grades and oxidation rates, the leaching rate of cobalt dolomite is significantly lower, and the net acid consumption is much higher than that of other copper-cobalt ores with similar grades. That is, under the same treatment process conditions, the recovery effect of copper and cobalt in cobalt dolomite copper-cobalt ore is poor and the acid consumption is higher. This also reflects the poor recovery effect and high cost of treating cobalt dolomite by conventional processes.

Claims

1. A method for neutralizing raffinate with low-copper cobalt dolomite and simultaneously recovering copper and cobalt, characterized in that: include: The raw ore pulp of the cobalt dolomite is subjected to a neutralization reaction with the raffinate I to obtain a neutralized slurry; the neutralized slurry is solid-liquid separated to obtain a neutralized liquid and a neutralized slag; The neutralized residue is mixed with the raffinate II for leaching to obtain a leached slurry; the leached slurry is solid-liquid separated to obtain a leached liquid and leached residue; The copper grade of the cobalt dolomite is less than 1.8wt%; the oxidation rate of the cobalt dolomite is more than 55wt%; The sulfuric acid content in the raffinate I is greater than 8 g / L; the sulfuric acid content in the raffinate II is greater than 8 g / L; The raffinate II contains more than 1 g / L of iron; The leaching temperature of the mixed leaching of the neutralized residue and the raffinate II is above 55°C.

2. The method for neutralizing the raffinate with low-copper cobalt dolomite and simultaneously recovering copper and cobalt according to claim 1, characterized in that: The copper grade of the cobalt dolomite is 0.8wt% to 1.5wt%; the cobalt grade of the cobalt dolomite is 0.3wt% to 0.6wt%; the oxidation rate of the cobalt dolomite is above 60wt%; The raw ore pulp is obtained by grinding the cobalt dolomite; the particle fineness of the raw ore pulp is -0.074mm, and the content of the particle size is 75wt% to 85wt%; the concentration of the raw ore pulp is 50wt% to 55wt%.

3. The method for neutralizing raffinate with low-copper cobalt dolomite and simultaneously recovering copper and cobalt according to claim 1 or 2, characterized in that: The weight ratio of the raw ore pulp to the raffinate I is 1:4-10; the neutralization reaction time of the raw ore pulp and the raffinate I is 3-5 hours; The raffinate I comes from a hydrometallurgical process for recovering copper; the raffinate I contains 1.5 to 2.5 g / L of copper; the raffinate I contains 2.5 to 3.5 g / L of cobalt; the raffinate I contains 2.5 to 3.5 g / L of iron; the raffinate I contains 0.5 to 1.0 g / L of manganese; the raffinate I contains 0.5 to 0.8 g / L of calcium; the raffinate I contains 10 to 13 g / L of magnesium; the raffinate I contains 1.5 to 2.0 g / L of aluminum; and the raffinate I contains 15 to 25 g / L of sulfuric acid.

4. The method for neutralizing raffinate with low-copper cobalt dolomite and simultaneously recovering copper and cobalt according to any one of claims 1 to 3, characterized in that: The weight ratio of the neutralized residue to the raffinate II is 10-15:90-85; the leaching temperature of the mixed leaching of the neutralized residue and the raffinate II is 70-80° C.; the leaching time of the mixed leaching of the neutralized residue and the raffinate II is 3-5 hours; The raffinate II comes from a hydrometallurgical process for recovering copper; the raffinate II contains 1.5 to 2.5 g / L copper; the raffinate II contains 2.5 to 3.5 g / L cobalt; the raffinate II contains 2.5 to 3.5 g / L iron; the raffinate II contains 0.5 to 1.0 g / L manganese; the raffinate II contains 0.5 to 0.8 g / L calcium; the raffinate II contains 10 to 13 g / L magnesium; the raffinate II contains 1.5 to 2.0 g / L aluminum; the raffinate II contains 15 to 25 g / L sulfuric acid.

5. The method for neutralizing raffinate with low-copper cobalt dolomite and simultaneously recovering copper and cobalt according to any one of claims 1 to 4, characterized in that: It also includes: neutralizing the neutralization liquid and / or the leaching liquid to remove iron and aluminum to obtain an iron-removed aluminum slurry; and separating the iron-removed aluminum slurry into a solid-liquid phase to obtain an iron-removed aluminum liquid and an iron-aluminum slag.

6. The method of neutralizing the raffinate with low-copper cobalt dolomite and simultaneously recovering copper and cobalt according to claim 5, characterized in that: The neutralizing agent used for the iron removal and aluminum neutralization is lime; the neutralization end point of the iron removal and aluminum neutralization is when the pH value of the ore pulp is 3.8 to 4.

2.

7. The method of neutralizing the raffinate with low-copper cobalt dolomite and simultaneously recovering copper and cobalt according to claim 6, characterized in that: The neutralizing agent used for the iron and aluminum neutralization is lime milk with a concentration of 9wt% to 11wt%.

8. The method for neutralizing raffinate with low-copper cobalt dolomite and simultaneously recovering copper and cobalt according to any one of claims 1 to 7, characterized in that: The method also includes: neutralizing the iron and aluminum removal liquid with copper and cobalt to obtain copper and cobalt ore slurry; and separating the copper and cobalt ore slurry into solid and liquid to obtain copper and cobalt ore liquid and copper-cobalt slag.

9. The method for neutralizing raffinate with low-copper cobalt dolomite and simultaneously recovering copper and cobalt according to claim 8, characterized in that: The neutralizing agent used for the neutralization of the copper-cobalt precipitation is lime; the neutralization end point of the neutralization of the copper-cobalt precipitation is that the pH value of the ore pulp is 6.8-7.

2.

10. The method for neutralizing raffinate with low-copper cobalt dolomite and simultaneously recovering copper and cobalt according to claim 9, characterized in that: The neutralizing agent used for neutralizing the copper-cobalt precipitation is lime milk with a concentration of 9wt% to 11wt%.

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