Method for recovering cobalt precipitate from liquid after iron and aluminum removal from copper-cobalt ore

Abstract

The present invention provides a method for recovering cobalt precipitate from the liquid after iron and aluminum removal from copper-cobalt ore. The method comprises: step S1, mixing the liquid after iron and aluminum removal with a first alkaline solution for precipitation reaction, and concentrating and separating the obtained precipitation slurry to obtain a cobalt precipitation overflow and a cobalt precipitation underflow; step S2, dividing the underflow into two parts, adding a second alkaline solution to the first underflow for activation and conversion, returning the obtained activated ore slurry to step S1 to replace the first alkaline solution, and filtering and washing the second underflow; step S3, mixing the first cobalt precipitation overflow with the first alkaline solution, and performing precipitation reaction, concentrating and separating the precipitation slurry obtained by the precipitation reaction to obtain a cobalt precipitation underflow; step S4, dividing the cobalt precipitation underflow into two parts, adding a third alkaline solution to the first underflow for activation and conversion, returning the obtained activated ore slurry to step S3 to replace the first alkaline solution, and filtering and washing the second underflow. The product has large particle size and low water content.

Description

Technical Field

[0001] The invention relates to the technical field of copper-cobalt ore hydrometallurgy, and in particular to a method for recovering cobalt precipitate from copper-cobalt ore liquid after iron and aluminum removal. Background Art

[0002] At present, the wet treatment of copper-cobalt ore adopts atmospheric pressure leaching, extraction of copper and subsequent cobalt precipitation. The cobalt precipitation process generally adopts one-stage cobalt precipitation or two-stage cobalt precipitation, and the precipitant is magnesium hydroxide slurry after active magnesium oxide slurry, and finally obtains cobalt hydroxide product. The problem of this method is:

[0003] (1) The price of activated magnesium oxide is relatively high and its quality is unstable. Generally, the selected magnesium oxide manufacturer cannot be easily changed, otherwise it will affect the stability of the cobalt hydroxide product.

[0004] (2) Magnesium hydroxide reacts with cobalt sulfate to form magnesium sulfate, which is a laxative. If it is discharged directly, it will cause pollution to the local water environment.

[0005] (3) The product has a high magnesium content, and the cost of removing magnesium in the subsequent cobalt refining process is high.

[0006] If sodium hydroxide is used directly for precipitation, since sodium hydroxide is a strong base, the cobalt hydroxide formed will have small particle size and high degree of hydration, making it very difficult to settle and filter, which will bring great difficulties to the selection and production of engineering equipment. Summary of the invention

[0007] The main purpose of the present invention is to provide a method for recovering cobalt precipitate from the copper-cobalt ore liquid after iron and aluminum removal, so as to solve the problems of unstable quality, poor environmental protection, difficult post-treatment or difficult sedimentation and filtration when precipitating cobalt from the copper-cobalt ore liquid after iron and aluminum removal in the prior art.

[0008] In order to achieve the above-mentioned object, according to one aspect of the present invention, a method for recovering cobalt precipitate from the de-ironized and de-aluminized copper-cobalt ore liquid is provided, wherein the cations in the de-ironized and de-aluminized liquid include cobalt ions, manganese ions and magnesium ions, and the method for recovering cobalt precipitate comprises: step S1, mixing the de-ironized and de-aluminized liquid with a first alkaline solution to carry out a precipitation reaction, and densely separating the precipitation slurry obtained by the precipitation reaction to obtain a cobalt precipitation overflow and a cobalt precipitation underflow; step S2, dividing the cobalt precipitation underflow into a first underflow and a second underflow, adding a second alkaline solution to the first underflow for a stage of activation conversion, and returning the obtained activated ore slurry to step S 1, replacing the first alkaline solution and mixing it with the liquid after iron and aluminum removal, filtering the second first underflow, washing, and obtaining a cobalt hydroxide product; step S3, mixing the first cobalt precipitation overflow with the first alkaline solution, performing a second-stage precipitation reaction, and concentrating the precipitation slurry obtained by the second-stage precipitation reaction to obtain a second-stage cobalt precipitation underflow; step S4, dividing the second-stage cobalt precipitation underflow into a first-second underflow and a second-second underflow, adding a third alkaline solution to the first-second underflow for a second-stage activation conversion, returning the obtained activated ore pulp to step S3 to replace the first alkaline solution and mix it with the first overflow, filtering the second-second underflow, and washing to obtain a manganese cobalt hydroxide product.

[0009] Further, the first alkaline solution and / or the second alkaline solution and / or the third alkaline solution are selected from any one or more of a sodium hydroxide solution, a potassium hydroxide solution and a calcium hydroxide suspension;

[0010] Preferably, the concentration of the first alkaline solution and / or the second alkaline solution and / or the third alkaline solution is 3 wt% to 40 wt%;

[0011] Preferably, based on the theoretical molar amount of hydroxide required for the first precipitation reaction, the molar amount of hydroxide in the second alkaline solution is 0.6-1.0 times the theoretical molar amount;

[0012] Preferably, based on the theoretical molar amount of hydroxide required for the second-stage precipitation reaction, the molar amount of hydroxide in the third alkaline solution is 0.6-1.0 times the theoretical molar amount.

[0013] Furthermore, the temperature of one precipitation reaction in step S1 is 40-70° C.; preferably, the time of one precipitation reaction is 1.0-5.0 h.

[0014] Furthermore, the reaction time of one activation conversion in step S2 is 1 to 10 minutes; preferably, the reaction temperature of one activation conversion is room temperature to 90°C.

[0015] Furthermore, the temperature of the second-stage precipitation reaction in step S3 is 40-70° C.; preferably, the time of the second-stage precipitation reaction is 1.0-5.0 h.

[0016] Furthermore, step S3 includes adding an oxidant during the second-stage precipitation reaction. Preferably, the oxidant includes any one or more of hydrogen peroxide, sodium persulfate, potassium persulfate, ammonium persulfate and oxygen-containing gas.

[0017] Furthermore, the reaction time of the second-stage activation conversion in step S4 is 1 to 10 minutes; preferably, the reaction temperature of the second-stage activation conversion is room temperature to 90°C.

[0018] Further, in step S1, the endpoint pH of the first-stage precipitation reaction is controlled to be 7.4-7.8; and / or, the endpoint pH of the second-stage precipitation reaction in step S3 is controlled to be 7.8-8.4.

[0019] Further, in step S2, the amount of solids in the first stage underflow is 2 to 16 times the weight of the cobalt hydroxide product generated in the second stage underflow;

[0020] And / or, in step S4, the amount of solids in the first-stage underflow is 2 to 16 times the weight of the manganese cobalt hydroxide product generated in the second-stage underflow.

[0021] Furthermore, after iron and aluminum removal, the cobalt ion concentration in the liquid is 0.01-20 g / L, the manganese ion concentration is 0.01-20 g / L, and the magnesium ion concentration is 0.01-20 g / L.

[0022] The technical scheme of the present invention is applied, and the feature of containing magnesium ions in the above-mentioned cobalt-containing solution is utilized. After the cobalt precipitation reaction is completed, the magnesium ions remain in the solution. A part of the magnesium ions exists in the bottom flow slurry phase obtained after dense separation. Alkali is added to the slurry, which can react with the magnesium ions to generate highly active magnesium hydroxide, and then immediately returned to the cobalt precipitation reaction tank. The highly active magnesium hydroxide directly reacts with cobalt sulfate to generate the product cobalt hydroxide. The conversion rate of magnesium ions in the bottom flow slurry is high, that is, less magnesium is retained in the product. In addition, the magnesium hydroxide generated by conversion is subjected to the cobalt precipitation reaction, which avoids the disadvantages of strong alkali precipitation of cobalt such as sodium hydroxide. The generated cobalt hydroxide precipitation particle size is large, the degree of hydration is low, the sedimentation and filtration performance is good, the engineering equipment selection is small, the investment is saved, and the production control is easy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0024] Figure 1 A schematic diagram of a process for recovering cobalt precipitate from liquid after iron and aluminum removal according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] As analyzed in the background technology of this application, in the prior art, when cobalt is precipitated from the copper-cobalt ore after iron and aluminum are removed, there are problems such as unstable quality, poor environmental protection, difficulty in post-treatment, or difficulty in sedimentation and filtration.

[0027] In order to solve this problem, the present application provides a method for recovering cobalt precipitate from the liquid after iron and aluminum removal of copper-cobalt ore, wherein the cations in the liquid after iron and aluminum removal include cobalt ions, manganese ions and magnesium ions, and the method for recovering cobalt precipitate includes: step S1, mixing the liquid after iron and aluminum removal with a first alkaline solution to perform a precipitation reaction, and densely separating the precipitation slurry obtained by the precipitation reaction to obtain a cobalt precipitation overflow and a cobalt precipitation bottom flow; step S2, dividing the cobalt precipitation bottom flow into a first underflow and a second underflow, adding a second alkaline solution to the first underflow for a stage of activation conversion, and returning the obtained activated ore slurry to the step S1 for replacement; The first alkaline solution is mixed with the liquid after iron and aluminum removal, and the second first-stage underflow is filtered and washed to obtain a cobalt hydroxide product; step S3, the first-stage cobalt precipitation overflow is mixed with the first alkaline solution, a second-stage precipitation reaction is carried out, and the precipitation slurry obtained by the second-stage precipitation reaction is concentrated and separated to obtain a second-stage cobalt precipitation underflow; step S4, the second-stage cobalt precipitation underflow is divided into a first-stage underflow and a second-stage underflow, the third alkaline solution is added to the first-stage underflow for two-stage activation conversion, the obtained activated ore pulp is returned to step S3 to replace the first alkaline solution and mix with the first overflow, and the second-stage underflow is filtered and washed to obtain a manganese cobalt hydroxide product.

[0028] The above-mentioned method for recovering cobalt precipitation provided by the present application utilizes the characteristics of magnesium ions contained in the above-mentioned cobalt-containing solution. After the cobalt precipitation reaction is completed, the magnesium ions remain in the solution. A part of the magnesium ions exists in the underflow ore slurry phase obtained after dense separation. Alkali is added to the ore slurry, which can react with the magnesium ions to generate highly active magnesium hydroxide, and then immediately returned to the cobalt precipitation reaction tank. The highly active magnesium hydroxide directly reacts with cobalt sulfate to generate the product cobalt hydroxide, and the magnesium ion conversion rate in the underflow ore slurry is high, that is, magnesium is retained less in the product. In addition, the magnesium hydroxide generated by the conversion is subjected to the cobalt precipitation reaction, which avoids the disadvantages of strong alkali precipitation of cobalt such as sodium hydroxide, and the generated cobalt hydroxide precipitation has a large particle size, a low degree of hydration, good sedimentation and filtration performance, small selection of engineering equipment, saving investment, and easy production control.

[0029] The cobalt recovery precipitation method introduced in the present application adopts a two-stage cobalt precipitation method, uses an alkaline solution as a precipitant to start the cobalt precipitation process, and respectively passes the activated ore pulp of the first and second stage cobalt precipitation processes into the first and second stage cobalt precipitation reactions. The final ore pulp obtains a high-quality first-stage cobalt hydroxide product and a second-stage cobalt-manganese hydroxide product with good sedimentation performance and good filtration performance, thereby realizing efficient and sufficient recovery of cobalt and manganese in the liquid after iron and aluminum removal from the copper-cobalt ore.

[0030] The method for recovering cobalt precipitate of the present application has no special requirements for the concentrations of the first alkaline solution, the second alkaline solution and the third alkaline solution. Those skilled in the art can select according to actual conditions. In some embodiments of the present application, the concentrations of the first alkaline solution and / or the second alkaline solution and / or the third alkaline solution are 3wt% to 40wt%. In some embodiments of the present application, the first alkaline solution, the second alkaline solution and the third alkaline solution are independently selected from any one or more of sodium hydroxide solution, potassium hydroxide solution and calcium hydroxide suspension. Preferably, the first alkaline solution, the second alkaline solution and the third alkaline solution are all sodium hydroxide solutions. Therefore, sodium hydroxide is not only cheap and easy to obtain, but also has abundant sources, and has a more prominent activation and conversion effect on ore pulp, and has a high conversion rate on magnesium ions, which is conducive to further improving the yield and purity of cobalt hydroxide and cobalt manganese hydroxide products.

[0031] The first alkaline solution is added only when the first stage cobalt precipitation process and the second stage cobalt precipitation process are started up. After the system is running, it is replaced by the activated ore pulp after the corresponding first or second stage activation conversion. There is no special requirement for its dosage, which can be determined according to the amount of cobalt ions in the solution.

[0032] There are no special requirements for the operating conditions of the above-mentioned one-stage precipitation reaction, and the relevant process parameters can be determined by referring to the prior art. In some typical embodiments of the present application, the temperature of the one-stage precipitation reaction in step S1 is 40-70°C; preferably, the time of the one-stage precipitation reaction is 1.0-5.0h. In some embodiments of the present application, in order to further improve the purity of the main cobalt hydroxide product and avoid a large amount of magnesium and manganese precipitating into the cobalt hydroxide product, in step S1, the endpoint pH of the one-stage precipitation reaction is controlled to be 7.4-7.8.

[0033] In the above-mentioned step S2, a section of cobalt precipitation underflow obtained by dense separation is processed to prepare a cobalt hydroxide product. In some typical embodiments of the present application, a section of cobalt precipitation underflow is divided into a first section underflow and a second section underflow, and the amount of solids in the first section underflow is 2 to 16 times the weight of the cobalt hydroxide product generated in the second section underflow. Exemplarily, the amount of solids in the first section underflow is 2 times, 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, 10 times, 11 times, 12 times, 13 times, 14 times, 15 times, 16 times or any range between the two of the weight of the cobalt hydroxide product generated in the second section underflow. The second section underflow is filtered and washed to obtain the cobalt hydroxide product, and the specific operation method of filtering and washing can be easily determined by those skilled in the art according to the prior art.

[0034] In order to better balance the yield and purity of the main cobalt hydroxide product, in some embodiments of the present application, based on the theoretical molar amount of hydroxide required for cobalt precipitation in the mixed solution to be subjected to a precipitation reaction, the molar amount of hydroxide in the second alkaline solution added for activation and conversion in step S2 is 0.6-1.0 times the theoretical molar amount. In some embodiments, the multiple of the molar amount of hydroxide in the alkaline solution to the theoretical molar amount is called the dosage coefficient of the alkaline solution.

[0035] In some embodiments of the present application, the reaction time of the activation conversion in step S2 is 1 to 10 minutes, and the activated slurry obtained is immediately returned to the above step S1 to be mixed with the above iron and aluminum removal liquid. Preferably, the reaction temperature of the activation conversion is room temperature-90°C, and the conversion rate of active magnesium hydroxide in the activated slurry obtained by the activation conversion at this temperature is high, and the cobalt precipitation effect as a precipitant is better.

[0036] The first stage cobalt precipitation overflow obtained by dense separation in step S1 can obtain a high-quality cobalt-manganese hydroxide product with good ore settling performance and good filtration performance through a second stage cobalt precipitation reaction. In some embodiments of the present application, the temperature of the second stage precipitation reaction in step S3 is 40-70°C; preferably, the time of the second stage precipitation reaction is 1.0-5.0h.

[0037] In some typical embodiments of the present application, step S3 includes adding an oxidant during the second-stage precipitation reaction, so that the divalent manganese ions in the solution are converted into trivalent manganese ions and converted into precipitates in the second-stage precipitation reaction, thereby further improving the yield of manganese hydroxide. Preferably, the above-mentioned oxidant includes any one or more of hydrogen peroxide, sodium persulfate, potassium persulfate, ammonium persulfate and oxygen-containing gas, wherein the oxygen concentration of the oxygen-containing gas is not particularly limited and can be selected according to specific circumstances, such as using air or oxygen with a purity of more than 99%. In order to further improve the recovery rate and quality of the manganese-cobalt precipitation product, in some embodiments of the present application, the endpoint pH of the second-stage precipitation reaction is 7.8-8.4.

[0038] The precipitation slurry obtained by the above-mentioned two-stage precipitation reaction is concentrated and separated, and the overflow part obtained by separation can be processed with reference to the prior art, and this application will not be described in detail. The separated two-stage cobalt precipitation bottom flow is divided into the first two-stage bottom flow and the second two-stage bottom flow. The second two-stage bottom flow is filtered and washed to obtain the manganese cobalt hydroxide product; the other part, that is, the first one-stage bottom flow, is activated and converted, and the slurry obtained by the activation treatment is immediately passed into the second-stage cobalt precipitation reactor and mixed with the first-stage cobalt precipitation overflow. In some typical embodiments of the present application, the amount of solids in the first two-stage bottom flow is 2 to 16 times the weight of the manganese cobalt hydroxide product generated in the second two-stage bottom flow.

[0039] In some embodiments of the present application, the reaction time of the second stage activation conversion in the above step S4 is 1 to 10 minutes, and preferably, the reaction temperature of the activation conversion is room temperature to 90° C. In some embodiments, in order to better balance the yield and purity of the manganese cobalt hydroxide product, the molar amount of hydroxide in the third alkaline solution added for activation conversion in step S2 is 0.6-1.0 times the theoretical molar amount of hydroxide required for cobalt precipitation in the mixed solution to be subjected to the second stage precipitation reaction.

[0040] The above-mentioned method for recovering cobalt precipitate of the present application is applicable to the liquid after the iron and aluminum are removed from the wet leaching of copper-cobalt ore, especially for the solution containing the following components, the precipitation effect is better: cobalt ion concentration is 0.1-20g / L, manganese ion concentration is 0.1-20g / L, and magnesium ion concentration is 0.1-20g / L.

[0041] The beneficial effects that can be achieved by the present application will be further illustrated below in combination with embodiments and comparative examples.

[0042] The objects treated in the following examples and comparative examples are aqueous solutions after iron and aluminum removal after wet leaching of copper-cobalt ore, wherein the cobalt ion concentration is 0.01-20 g / L, the manganese ion concentration is 0.01-20 g / L, and the magnesium ion concentration is 0.01-20 g / L.

[0043] Example 1

[0044] This embodiment follows Figure 1 The process flow shown is to recover cobalt precipitate from the liquor after dealuminization and iron removal.

[0045] Step 1: add a sodium hydroxide solution with a mass concentration of 10% to the liquid after iron and aluminum removal, the dosage coefficient of the sodium hydroxide solution (i.e. the multiple of the molar amount of hydroxide in the alkaline solution to the theoretical molar amount, the same below) is 0.9, and a cobalt precipitation reaction is carried out. The cobalt precipitation reaction temperature is 60°C, the reaction time is 3h, and the reaction end point pH is 7.5, followed by dense separation to obtain a cobalt precipitation overflow and a cobalt precipitation underflow.

[0046] Step 2: Part of the first stage cobalt precipitation bottom flow is mixed with sodium hydroxide aqueous solution (concentration is 10wt%) for activation conversion, the dosage coefficient of sodium hydroxide aqueous solution is 0.9, the activation reaction temperature should be controlled at 65°C, the activation time is controlled at 3min, and an activated slurry is obtained, and the solid content in the activated slurry is 8 times the mass of the cobalt hydroxide product. The activated slurry is mixed with a new batch of iron and aluminum removal liquid to carry out a first stage cobalt precipitation reaction, and the reaction time, temperature and endpoint pH value remain unchanged. Another part of the first stage cobalt precipitation bottom flow is filtered and washed to obtain a first stage cobalt hydroxide product.

[0047] The first batch of cobalt hydroxide products (i.e. using sodium hydroxide as the first-stage cobalt precipitation precipitant) were tested and the particle size D50 of the cobalt hydroxide products was 3um, the cobalt content in the product was 38%, the magnesium content was 0.5%, the manganese content was 5%, the water content was 75%, and the cobalt precipitation rate was 85%; the particle size D50 of the cobalt hydroxide products in subsequent batches (i.e. using activated ore pulp as the first-stage cobalt precipitation reagent) was 10um, the cobalt content in the product was 38%, the magnesium content was 0.5%, the manganese content was 5%, the water content was 60%, and the cobalt precipitation rate was 85%.

[0048] Step three, add a sodium hydroxide solution with a mass concentration of 10% to the first cobalt precipitation overflow, the dosage coefficient of the sodium hydroxide solution is 1.0, and introduce oxygen to carry out a second cobalt precipitation reaction. The temperature of the cobalt precipitation reaction is 65°C, the reaction time is 3h, and the reaction end point pH is 8.2, followed by dense separation to obtain a second cobalt precipitation overflow and a second cobalt precipitation underflow.

[0049] Step 4, part of the second stage cobalt precipitation bottom flow is mixed with sodium hydroxide aqueous solution (concentration is 10wt%) for activation conversion, the dosage coefficient of sodium hydroxide aqueous solution is 1.0, the activation reaction temperature should be controlled at 65°C, the activation time is controlled at 3min, and an activated slurry is obtained, and the solid amount in the activated slurry is 8 times the mass of the cobalt hydroxide manganese product. The activated slurry is mixed with a new batch of first stage cobalt precipitation overflow to carry out a second stage cobalt precipitation reaction, and the reaction time, temperature and endpoint pH value remain unchanged. Another part of the second stage cobalt precipitation bottom flow is filtered and washed to obtain a second stage sodium hydroxide cobalt manganese product.

[0050] The first batch of cobalt manganese hydroxide products (i.e. using sodium hydroxide as the second-stage cobalt precipitation precipitant) were tested and found that the particle size D50 of the cobalt manganese hydroxide products was 10um, the cobalt content in the product was 10%, the magnesium content was 13%, the manganese content was 15%, the water content was 75%, and the cobalt precipitation rate was 99.5%; the particle size D50 of the cobalt manganese hydroxide products in subsequent batches (i.e. using activated ore pulp as the second-stage cobalt precipitation reagent) was 10um, the cobalt content in the product was 10%, the magnesium content was 13%, the manganese content was 15%, the water content was 60%, and the cobalt precipitation rate was 99.5%.

[0051] Example 2

[0052] Step 1: add a sodium hydroxide solution with a mass concentration of 10% to the liquid after iron and aluminum removal, the dosage coefficient of the sodium hydroxide solution is 1.05, and carry out a cobalt precipitation reaction. The cobalt precipitation reaction temperature is 60°C, the reaction time is 3h, and the reaction end point pH is 8.0. Then, dense separation is carried out to obtain a cobalt precipitation overflow and a cobalt precipitation bottom flow.

[0053] Step 2: Part of the first stage cobalt precipitation bottom flow is mixed with sodium hydroxide aqueous solution (concentration is 10wt%) for activation conversion, the dosage coefficient of sodium hydroxide aqueous solution is 1.05, the activation reaction temperature should be controlled at 65°C, the activation time is controlled at 3min, and an activated slurry is obtained, and the solid content in the activated slurry is 8 times the mass of the cobalt hydroxide product. The activated slurry is mixed with a new batch of iron and aluminum removal liquid to carry out a first stage cobalt precipitation reaction, and the reaction time, temperature and endpoint pH value remain unchanged. Another part of the first stage cobalt precipitation bottom flow is filtered and washed to obtain a first stage cobalt hydroxide product.

[0054] The first batch of cobalt hydroxide products (i.e. using sodium hydroxide as the first-stage cobalt precipitation precipitant) were tested and the particle size D50 of the cobalt hydroxide products was 3um, the cobalt content in the product was 30%, the magnesium content was 5%, the manganese content was 10%, the water content was 75%, and the cobalt precipitation rate was 97%; the particle size D50 of the cobalt hydroxide products in subsequent batches (i.e. using activated ore pulp as the first-stage cobalt precipitation reagent) was 10um, the cobalt content in the product was 30%, the magnesium content was 5%, the manganese content was 10%, the water content was 60%, and the cobalt precipitation rate was 97%.

[0055] The implementation method of step three and step four is the same as implementation 1. The particle size D50 of the cobalt manganese hydroxide product obtained by using the activated ore pulp as the second-stage cobalt precipitation reagent is 10um, the cobalt content in the product is 10%, the magnesium content is 13%, the manganese content is 15%, the water content is 60%, and the cobalt precipitation rate is 99.5%.

[0056] Example 3

[0057] Step 1: add a sodium hydroxide solution with a mass concentration of 10% to the liquid after iron and aluminum removal, the dosage coefficient of the sodium hydroxide solution is 0.85, and carry out a cobalt precipitation reaction. The cobalt precipitation reaction temperature is 60°C, the reaction time is 3h, and the reaction end point pH is 7.0, followed by dense separation to obtain a cobalt precipitation overflow and a cobalt precipitation underflow.

[0058] Step 2: Part of the first stage cobalt precipitation bottom flow is mixed with sodium hydroxide aqueous solution (concentration is 10wt%) for activation conversion, the dosage coefficient of sodium hydroxide aqueous solution is 0.85, the activation reaction temperature should be controlled at 65°C, the activation time is controlled at 3min, and an activated slurry is obtained, and the solid content in the activated slurry is 8 times the mass of the cobalt hydroxide product. The activated slurry is mixed with a new batch of iron and aluminum removal liquid to carry out a first stage cobalt precipitation reaction, and the reaction time, temperature and endpoint pH value remain unchanged. Another part of the first stage cobalt precipitation bottom flow is filtered and washed to obtain a first stage cobalt hydroxide product.

[0059] The first batch of cobalt hydroxide products (i.e. using sodium hydroxide as the first-stage cobalt precipitation precipitant) were tested and the particle size D50 of the cobalt hydroxide products was 3um, the cobalt content in the product was 40%, the magnesium content was 0.3%, the manganese content was 3%, the water content was 75%, and the cobalt precipitation rate was 78%; the particle size D50 of the cobalt hydroxide products in subsequent batches (i.e. using activated ore pulp as the first-stage cobalt precipitation reagent) was 10um, the cobalt content in the product was 40%, the magnesium content was 0.3%, the manganese content was 3%, the water content was 60%, and the cobalt precipitation rate was 78%.

[0060] The implementation method of step three and step four is the same as implementation 1. The particle size D50 of the cobalt manganese hydroxide product obtained by using the activated ore pulp as the second-stage cobalt precipitation reagent is 10um, the cobalt content in the product is 10%, the magnesium content is 13%, the manganese content is 15%, the water content is 60%, and the cobalt precipitation rate is 99.5%.

[0061] Example 4

[0062] Step 1 and step 2 are the same as Example 1, and the difference from Example 1 is that in step 3, the pH value of the reaction end point is controlled to be 8.4, and in step 4, the dosage coefficient of the sodium hydroxide solution mixed with part of the second stage cobalt precipitation underflow is 1.2.

[0063] The particle size D50 of the cobalt manganese hydroxide product finally obtained by using the activated ore pulp as the second-stage cobalt precipitation reagent is 10um, the cobalt content in the product is 5%, the magnesium content is 13%, the manganese content is 15%, the water content is 75%, and the cobalt precipitation rate is 99.5%.

[0064] Example 5

[0065] Step 1 and step 2 are the same as Example 1, and the difference from Example 1 is that in step 3, the pH value of the reaction endpoint is controlled to be 7.8, and in step 4, the dosage coefficient of the sodium hydroxide solution mixed with part of the second-stage cobalt precipitation bottom flow is 0.85.

[0066] The particle size D50 of the cobalt manganese hydroxide product finally obtained by using the activated ore pulp as the second-stage cobalt precipitation reagent is 10um, the cobalt content in the product is 9.5%, the magnesium content is 13%, the manganese content is 15%, the water content is 60%, and the cobalt precipitation rate is 95%.

[0067] Example 6

[0068] The difference from implementation 1 is that in step 2, the amount of solids in the activated slurry is twice the mass of the cobalt hydroxide product generated, and in step 4, the amount of solids in the activated slurry is twice the mass of the cobalt manganese hydroxide product generated.

[0069] After testing, the particle size D50 of the cobalt hydroxide product obtained by using the activated ore pulp as the first-stage cobalt precipitation reagent is 8um, the cobalt content in the product is 40%, the magnesium content is 0.5%, the manganese content is 5%, the water content is 65%, and the cobalt precipitation rate is 85%; the particle size D50 of the cobalt manganese hydroxide product obtained by using the activated ore pulp as the second-stage cobalt precipitation reagent is 8um, the cobalt content in the product is 5%, the magnesium content is 13%, the manganese content is 15%, the water content is 65%, and the cobalt precipitation rate is 85%.

[0070] Example 7

[0071] The difference from implementation 1 is that in step 2, the amount of solids in the activated slurry is 16 times the mass of the cobalt hydroxide product generated, and in step 4, the amount of solids in the activated slurry is 16 times the mass of the cobalt manganese hydroxide product generated.

[0072] After testing, the particle size D50 of the cobalt hydroxide product obtained by using the activated ore pulp as the first-stage cobalt precipitation reagent is 15um, the cobalt content in the product is 40%, the magnesium content is 0.5%, the manganese content is 5%, the water content is 50%, and the cobalt precipitation rate is 85%; the particle size D50 of the cobalt manganese hydroxide product obtained by using the activated ore pulp as the second-stage cobalt precipitation reagent is 15um, the cobalt content in the product is 5%, the magnesium content is 13%, the manganese content is 15%, the water content is 50%, and the cobalt precipitation rate is 99.5%.

[0073] Example 8

[0074] The difference from Example 1 is that the sodium hydroxide solution is replaced by a calcium hydroxide suspension with the same dosage coefficient.

[0075] The first batch of cobalt hydroxide products obtained in step 2 was tested, and the particle size D50 of the cobalt hydroxide product was 10 μm, the cobalt content in the product was 15%, the magnesium content was 2%, the manganese content was 1.2%, the water content was 70%, and the cobalt precipitation rate was 85%; the particle size D50 of the cobalt hydroxide products in subsequent batches was 10 μm, the cobalt content in the product was 15%, the magnesium content was 2%, the manganese content was 1.2%, the water content was 50%, and the cobalt precipitation rate was 85%.

[0076] The first batch of cobalt manganese hydroxide products obtained in step 4 was tested, and the particle size D50 of the cobalt manganese hydroxide product was 10 μm, the cobalt content of the product was 4%, the magnesium content was 5%, the manganese content was 5%, the water content was 70%, and the cobalt precipitation rate was 99.5%; the particle size D50 of the cobalt manganese hydroxide products in subsequent batches was 10 μm, the cobalt content of the product was 4%, the magnesium content was 5%, the manganese content was 5%, the water content was 70%, and the cobalt precipitation rate was 99.5%.

[0077] Comparative Example 1

[0078] Add active magnesium oxide milk with a concentration of 15% to the liquid after iron and aluminum removal, and carry out a first-stage cobalt precipitation reaction for 300 minutes under the condition of controlling the pH value to 8.15. After the reaction is completed, solid-liquid separation is carried out to obtain a first-stage cobalt hydroxide product and a cobalt precipitation liquid; add lime milk to the first-stage cobalt precipitation liquid, and carry out a second-stage cobalt precipitation reaction for 60 minutes under the condition of controlling the pH value to 8.45. After the reaction is completed, solid-liquid separation is carried out to obtain a second-stage cobalt precipitation slag.

[0079] After testing, the particle size D50 of the first-stage cobalt hydroxide is 12um, the cobalt content in the product is 35%, the magnesium content is 6%, the manganese content is 6%, the water content is 50%, and the cobalt precipitation rate is 90%; the particle size D50 of the second-stage cobalt precipitation slag is 12um, the cobalt content in the product is 10%, the magnesium content is 15%, the manganese content is 15%, the water content is 50%, and the cobalt precipitation rate is 99.5%.

[0080] From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: the above-mentioned method for recovering cobalt precipitation provided by the present application utilizes the characteristics of magnesium ions contained in the above-mentioned cobalt-containing solution. After the cobalt precipitation reaction is completed, the magnesium ions remain in the solution. There is a part of magnesium ions in the bottom flow ore slurry phase obtained after dense separation. Sodium hydroxide is added to the ore slurry, which can react with magnesium ions to generate highly active magnesium hydroxide, and then immediately returned to the cobalt precipitation reaction tank. Highly active magnesium hydroxide directly reacts with cobalt sulfate to generate product cobalt hydroxide, and the magnesium ion conversion rate in the bottom flow ore slurry is high, that is, magnesium is retained less in the product. In addition, the magnesium hydroxide generated by conversion is subjected to cobalt precipitation reaction, which avoids the disadvantages of sodium hydroxide strong base precipitation of cobalt, and the generated cobalt hydroxide precipitation particle size is large, the degree of hydration is low, the sedimentation and filtration performance is good, the engineering equipment selection is small, the investment is saved, and the production control is easy. In addition, the cobalt recovery and precipitation method adopts a two-stage cobalt precipitation method, uses sodium hydroxide as a precipitant to start the cobalt precipitation process, and respectively passes the activated slurries of the first and second stage cobalt precipitation processes into the first and second stage cobalt precipitation reactions. The final slurries obtain high-quality first-stage cobalt hydroxide products and second-stage cobalt-manganese hydroxide products with good sedimentation performance and good filtration performance, thereby achieving efficient and sufficient recovery of cobalt and manganese in the liquid after iron and aluminum removal from the copper-cobalt ore.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for recovering cobalt precipitate from the copper-cobalt ore liquid after iron and aluminum removal, wherein the cations in the copper-cobalt ore liquid after iron and aluminum removal include cobalt ions, manganese ions and magnesium ions, characterized in that: The method for recovering cobalt precipitate comprises: Step S1, mixing the liquid after iron and aluminum removal with the first alkaline solution to perform a precipitation reaction, controlling the endpoint pH of the precipitation reaction to be 7.4-7.8, and performing dense separation on the precipitation slurry obtained by the precipitation reaction to obtain a cobalt precipitation overflow and a cobalt precipitation underflow; Step S2, dividing the first stage of cobalt precipitation underflow into a first stage of underflow and a second stage of underflow, adding a second alkaline solution to the first stage of underflow for a stage of activation conversion, returning the obtained activated ore pulp to the step S1 to replace the first alkaline solution and mix with the iron and aluminum removal liquid, filtering and washing the second stage of underflow to obtain a cobalt hydroxide product, wherein the amount of solids in the first stage of underflow is 2 to 16 times the weight of the cobalt hydroxide product generated in the second stage of underflow; Step S3, mixing the first stage cobalt precipitation overflow with the first alkaline solution to perform a second stage precipitation reaction, wherein the endpoint pH of the second stage precipitation reaction is 7.8-8.4, and performing dense separation on the precipitation slurry obtained by the second stage precipitation reaction to obtain a second stage cobalt precipitation underflow; Step S4, dividing the second-stage cobalt precipitation bottom flow into a first-stage bottom flow and a second-stage bottom flow, adding a third alkaline solution to the first-stage bottom flow for two-stage activation conversion, returning the obtained activated ore pulp to step S3 to replace the first alkaline solution and mix with the first overflow, filtering and washing the second-stage bottom flow to obtain a manganese cobalt hydroxide product, and the amount of solids in the first-stage bottom flow is 2 to 16 times the weight of the manganese cobalt hydroxide product generated in the second-stage bottom flow.

2. The method for recovering cobalt precipitate according to claim 1, characterized in that: The first alkaline solution and / or the second alkaline solution and / or the third alkaline solution are selected from any one or more of a sodium hydroxide solution, a potassium hydroxide solution and a calcium hydroxide suspension.

3. The method for recovering cobalt precipitate according to claim 2, characterized in that: The concentration of the first alkaline solution and / or the second alkaline solution and / or the third alkaline solution is 3 wt % to 40 wt %.

4. The method for recovering cobalt precipitate according to claim 2, characterized in that: Based on the theoretical molar amount of hydroxide required for the first stage precipitation reaction, the molar amount of hydroxide in the second alkaline solution is 0.6-1.0 times the theoretical molar amount.

5. The method for recovering cobalt precipitate according to claim 2, characterized in that: Based on the theoretical molar amount of hydroxide required for the second-stage precipitation reaction, the molar amount of hydroxide in the third alkaline solution is 0.6-1.0 times the theoretical molar amount.

6. The method for recovering cobalt precipitate according to claim 1, characterized in that: The temperature of the precipitation reaction in step S1 is 40-70°C.

7. The method for recovering cobalt precipitate according to claim 6, characterized in that: The time of the precipitation reaction is 1.0-5.0h.

8. The method for recovering cobalt precipitate according to claim 1, characterized in that: The reaction time of the activation conversion in step S2 is 1 to 10 minutes.

9. The method for recovering cobalt precipitate according to claim 8, characterized in that: The reaction temperature of the first stage activation conversion is room temperature-90°C.

10. The method for recovering cobalt precipitate according to claim 1, characterized in that: The temperature of the second-stage precipitation reaction in step S3 is 40-70°C.

11. The method for recovering cobalt precipitate according to claim 10, characterized in that: The time of the second stage precipitation reaction is 1.0-5.0h.

12. The method for recovering cobalt precipitate according to claim 1, characterized in that: The step S3 includes adding an oxidant during the second-stage precipitation reaction.

13. The method for recovering cobalt precipitate according to claim 12, characterized in that: The oxidant includes any one or more of hydrogen peroxide, sodium persulfate, potassium persulfate, ammonium persulfate and oxygen-containing gas.

14. The method for recovering cobalt precipitate according to claim 1, characterized in that: The reaction time of the second stage activation conversion in step S4 is 1 to 10 minutes.

15. The method for recovering cobalt precipitate according to claim 14, characterized in that: The reaction temperature of the second stage activation conversion is room temperature-90°C.

16. The method for recovering cobalt precipitate according to claim 1, characterized in that: The cobalt ion concentration in the liquid after iron and aluminum removal is 0.01-20 g / L, the manganese ion concentration is 0.01-20 g / L, and the magnesium ion concentration is 0.01-20 g / L.

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