Method for precipitating MHP via magnesium activation

Abstract

The present application belongs to the technical field of hydrometallurgy. Disclosed is a method for precipitating MHP via magnesium activation. The method comprises the following steps: S1, mixing a magnesium-containing solution with a sodium hydroxide solution, and then carrying out a precipitation reaction for 3-5 min to obtain a precipitant; S2, immediately mixing the precipitant with a solution obtained after the removal of iron and aluminum from lateritic nickel ore, and then carrying out a first-stage nickel-cobalt precipitation reaction to obtain a first-stage nickel-cobalt precipitation slurry; S3, carrying out a first thickening treatment on the first-stage nickel-cobalt precipitation slurry to obtain a first thickener underflow and a first thickener overflow; and S4, filtering the first thickener underflow to obtain an MHP product. In the present application, the magnesium-containing solution and the sodium hydroxide solution are mixed, and then the first-stage nickel-cobalt precipitation reaction is carried out immediately after the magnesium solution and the sodium hydroxide solution are controlled to be mixed and reacted for 3-5 min; therefore, a high-purity and high-quality MHP product can be obtained. Moreover, the entire method is simple, and is convenient for large-scale industrial application.

Description

Method for magnesium-activated precipitation of MHP TECHNICAL FIELD

[0001] The present application belongs to the technical field of hydrometallurgy, and particularly relates to a method for magnesium-activated precipitation of MHP. BACKGROUND

[0002] MHP (nickel-cobalt hydroxide) is an intermediate product of hydrometallurgy of laterite nickel ore, which can be used to produce nickel sulfate, fine nickel-cobalt hydroxide, nickel plate and other products, and has good application prospects.

[0003] At present, in the hydrometallurgical process of laterite nickel ore, a one-stage nickel-cobalt precipitation process is usually used to prepare MHP products. However, in the prior art, sodium hydroxide solution is usually used as a precipitant for nickel-cobalt precipitation treatment. During the addition of the precipitant, local over-alkalization may occur. Local over-alkalization may cause the pH of the local aqueous solution to be too high, thereby causing multiple metal ions (mainly including nickel ions, cobalt ions, magnesium ions and manganese ions) to be precipitated at the same time. This makes the precipitated product contain a large amount of impurity ions, resulting in poor quality of the prepared MHP product.

[0004] Therefore, there is an urgent need to propose a new treatment method to solve the above-mentioned problems existing in the prior art.

[0005] SUMMARY

[0006] The purpose of the present application is to provide a method for magnesium-activated precipitation of MHP. The purpose is to solve the problem of local over-alkalization in the preparation of MHP products by the existing one-stage nickel-cobalt precipitation process, thereby causing high impurity content and poor quality of the MHP product.

[0007] In a first aspect, the present application provides a method for magnesium-activated precipitation of MHP, comprising the following steps: S1, mixing a magnesium-containing solution with a sodium hydroxide solution, and precipitating for 3-5 min to obtain a precipitant; S2, immediately mixing the precipitant with a liquid after removing iron and aluminum from laterite nickel ore to perform a one-stage nickel-cobalt precipitation reaction, and obtaining a one-stage nickel-cobalt precipitation slurry; S3, performing a first thickening treatment on the one-stage nickel-cobalt precipitation slurry to obtain a first thickening underflow and a first thickening overflow; and S4, performing a filtration treatment on the first thickening underflow to obtain an MHP product.

[0008] In the present application, the inventors have found that mixing a magnesium-containing solution with a sodium hydroxide solution can reduce the alkalinity of the solution, thereby solving the problem of local over-alkalization when directly using a sodium hydroxide solution for one-stage nickel-cobalt precipitation to prepare an MHP product. Therefore, the use of the method of the present application can improve the purity and quality of the MHP product.

[0009] The inventors further found that the reaction time of the magnesium solution and the sodium hydroxide solution has an important influence on the quality of the MHP product. If the reaction time is too short, the alkalinity of the mixed solution will not change significantly, and there will still be a problem of local over-alkalinity in the subsequent one-stage nickel-cobalt precipitation reaction. If the reaction time is too long, the magnesium hydroxide precipitate will agglomerate and grow, forming crystals with a large particle size. When the one-stage nickel-cobalt precipitation reaction is performed, the magnesium hydroxide crystals are difficult to dissolve quickly, and thus are easily wrapped by the nickel-cobalt hydroxide crystals formed in the nickel-cobalt precipitation process, resulting in an increase in the impurity content of the MHP product. Therefore, after the magnesium solution and the sodium hydroxide solution are mixed and reacted for 3-5 min, the one-stage nickel-cobalt precipitation reaction is immediately performed. Since the reaction between magnesium and sodium hydroxide is slow, the formed crystals are small, and in the process of the one-stage nickel-cobalt precipitation reaction, the solution after the removal of iron and aluminum from the laterite nickel ore is quickly dissolved, so that it will not be coated in the nickel-cobalt hydroxide precipitate, and thus a MHP product with better quality can be obtained.

[0010] In some embodiments, in step S1, the concentration of magnesium ions in the magnesium-containing solution is 4-6 g / L, for example, can be 4 g / L, 4.5 g / L, 5 g / L, 5.5 g / L, 6 g / L or other values within the range; the mass fraction of the sodium hydroxide solution is 10-13%, for example, can be 10%, 11%, 12%, 13% or other values within the range; the volume ratio of the magnesium-containing solution to the sodium hydroxide solution is (8-15):100, for example, can be 8:100, 9:100, 10:100, 11:100, 12:100, 13:100, 14:100, 15:100 or other ratios within the range; the precipitation reaction further comprises: performing the precipitation reaction at a temperature of 50-65°C (for example, can be 50°C, 55°C, 60°C, 65°C or other values within the range), a stirring speed of 1-2 r / min (for example, can be 1 r / min, 1.2 r / min, 1.4 r / min, 1.6 r / min, 1.5 r / min, 2 r / min or other values within the range), and a pressure of normal pressure.

[0011] In some embodiments, in step S2, the solution after the removal of iron and aluminum from the laterite nickel ore comprises the following components: nickel 2-6 g / L, cobalt 0.1-0.5 g / L, manganese 2-3 g / L, and magnesium 4-10 g / L.

[0012] The laterite nickel ore after iron and aluminum removal solution provided in the application can have, for example, 2 g / L, 3 g / L, 4 g / L, 5 g / L, 6 g / L, or other values within the range, nickel, 0.1 g / L, 0.2 g / L, 0.3 g / L, 0.4 g / L, 0.5 g / L, or other values within the range, cobalt, 2 g / L, 2.2 g / L, 2.4 g / L, 2.6 g / L, 2.8 g / L, 3 g / L, or other values within the range, manganese, and 4 g / L, 6 g / L, 8 g / L, 10 g / L, or other values within the range, magnesium.

[0013] In some embodiments, in step S2, the pH value of the first-stage nickel-cobalt precipitation reaction is 6.8-7.2, for example, 6.8, 6.9, 7, 7.1, 7.2, or other values within the range; and the time is 4-6 h, for example, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, or other values within the range.

[0014] In some embodiments, in step S3, the method further comprises a second-stage nickel-cobalt precipitation reaction on the first thickener overflow to obtain a second-stage nickel-cobalt precipitation slurry, and then performing a second thickening treatment on the second-stage nickel-cobalt precipitation slurry to obtain a second thickener overflow, and continuing to perform a manganese precipitation treatment on the second thickener overflow to obtain a laterite nickel ore after manganese removal solution; and the laterite nickel ore after manganese removal solution is reused as a magnesium-containing solution.

[0015] In the application, the laterite nickel ore after manganese removal solution is reused as a magnesium-containing solution, thereby improving the utilization rate of raw materials.

[0016] In some embodiments, the magnesium ion concentration in the laterite nickel ore after manganese removal solution is 4-6 g / L, for example, 4 g / L, 4.5 g / L, 5 g / L, 5.5 g / L, 6 g / L, or other values within the range.

[0017] In some embodiments, the pH value of the second-stage nickel-cobalt precipitation reaction is 7.8-8.2, for example, 7.8, 7.9, 8, 8.2, or other values within the range.

[0018] In some embodiments, the pH value of the manganese precipitation treatment is 10.0-10.5, for example, 10.0, 10.1, 10.2, 10.3, 10.4, 10.5, or other values within the range.

[0019] In some embodiments, in step S3, the method further comprises reusing part of the first thickener underflow to the first-stage nickel-cobalt precipitation reaction step.

[0020] In some preferred embodiments, the reused part of the first thickener underflow accounts for 4 / 5-9.5 / 10 of the total amount of the first thickener underflow.

[0021] In the present application, by recycling part of the first thickening underflow to the first stage nickel-cobalt precipitation reaction step as seed crystals, the crystallization of nickel-cobalt hydroxide is promoted.

[0022] In some embodiments, in step S4, the filtration treatment comprises vacuum filtration or filter press filtration, and the filter cake is washed with distilled water during filtration.

[0023] The present application has the following advantages: unlike the prior art, the present application can reduce the alkalinity of the solution by mixing the magnesium-containing solution with the sodium hydroxide solution, thereby solving the problem of local over-alkalinity when directly using a sodium hydroxide solution to prepare MHP products in the first stage nickel-cobalt precipitation; further, by controlling the mixing reaction of the magnesium solution and the sodium hydroxide solution for 3-5 minutes, and then immediately performing the first stage nickel-cobalt precipitation reaction, MHP products with high purity and quality can be obtained, and the whole method is simple and convenient for large-scale industrial application. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a flow chart of the magnesium-activated precipitation MHP method in the present application. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0026] The experimental methods not specified in the embodiments are generally performed according to the conventional conditions and the conditions described in the manuals, or according to the conditions suggested by the manufacturers. The general equipment, materials, reagents, etc. used are commercially available, unless otherwise specified.

[0027] Referring to Figure 1, which is a flow chart of the method in the present application, specifically, the method comprises the following steps: mixing a magnesium-containing solution with a sodium hydroxide solution, then performing a precipitation reaction to obtain a precipitant; mixing the precipitant with a liquid after removing iron and aluminum from laterite nickel ore, then performing a first stage nickel-cobalt precipitation reaction to obtain a first stage nickel-cobalt precipitation slurry; performing a first thickening treatment on the first stage nickel-cobalt precipitation slurry to obtain a first thickening underflow and a first thickening overflow, wherein the first thickening overflow is subjected to a second stage nickel-cobalt precipitation reaction to obtain a second stage nickel-cobalt precipitation slurry, and then performing a second thickening treatment on the second stage nickel-cobalt precipitation slurry to obtain a second thickening overflow, and further performing a manganese precipitation treatment on the second thickening overflow to obtain a liquid after removing manganese from laterite nickel ore, and recycling the liquid after removing manganese from laterite nickel ore as the magnesium-containing solution; recycling part of the first thickening underflow to the first stage nickel-cobalt precipitation reaction step; and performing a filtration treatment on the remaining first thickening underflow to obtain MHP products.

[0028] The liquid phase obtained after iron and aluminum removal from laterite nickel ore used in the examples and comparative examples is the liquid phase obtained after acid leaching and two-stage iron and aluminum removal from laterite nickel ore. It mainly includes the following components: nickel 3.87 g / L, cobalt 0.41 g / L, manganese 2.73 g / L, and magnesium 6.44 g / L.

[0029] Example 1

[0030] A method for activating and precipitating magnesium-based phosphoric acid (MHP) includes the following steps:

[0031] S1. The manganese-removed liquid of laterite nickel ore is mixed with a 12% sodium hydroxide solution at a volume ratio of 11:100. The mixture is then subjected to a precipitation reaction for 4 minutes at a temperature of 55℃, a stirring speed of 1.5 r / min, and a pressure of atmospheric pressure to obtain a precipitant.

[0032] S2. Immediately mix the precipitant obtained in step S1 with the iron and aluminum removed liquid of laterite nickel ore, and carry out a nickel-cobalt precipitation reaction for 5 hours under the condition of pH 7 to obtain a nickel-cobalt precipitation slurry.

[0033] S3. The nickel-cobalt slurry obtained in step S2 is subjected to a first thickening treatment to obtain a first thickened underflow and a first thickened overflow. The first thickened overflow is subjected to a second nickel-cobalt precipitation reaction (pH 8.0) to obtain a second nickel-cobalt slurry. The second nickel-cobalt slurry is then subjected to a second thickening treatment to obtain a second thickened overflow. The second thickened overflow is further subjected to manganese precipitation treatment (pH 10.3) to obtain a manganese-removed liquid from laterite nickel ore. The manganese-removed liquid from laterite nickel ore is reused in step S1. 9 / 10 of the first thickened underflow is reused in step S2.

[0034] S4. Vacuum filtration is used to filter the remaining 1 / 10 of the first concentrated underflow, and the filter cake is washed with distilled water during filtration to obtain the MHP product.

[0035] Example 2

[0036] A method for activating and precipitating magnesium-based phosphoric acid (MHP) includes the following steps:

[0037] S1. The manganese-removed liquid of laterite nickel ore is mixed with a 13% sodium hydroxide solution at a volume ratio of 15:100. The mixture is then subjected to a precipitation reaction for 3 minutes at a temperature of 50℃, a stirring speed of 2r / min, and a pressure of atmospheric pressure to obtain a precipitant.

[0038] S2. Immediately mix the precipitant obtained in step S1 with the iron and aluminum removed liquid of laterite nickel ore, and carry out a nickel-cobalt precipitation reaction for 6 hours under the condition of pH 7.2 to obtain a nickel-cobalt precipitation slurry.

[0039] S3, the one-stage nickel-cobalt precipitation slurry obtained in step S2 is subjected to first thickening treatment to obtain first thickening underflow and first thickening overflow, wherein the first thickening overflow is subjected to two-stage nickel-cobalt precipitation reaction (pH value is 8.2) to obtain two-stage nickel-cobalt precipitation slurry, and the two-stage nickel-cobalt precipitation slurry is subjected to second thickening treatment to obtain second thickening overflow, and the second thickening overflow is subjected to manganese precipitation treatment (pH value is 10.5) to obtain red soil nickel ore manganese-removed liquid, and the red soil nickel ore manganese-removed liquid is reused in step S1; 9 / 10 of the first thickening underflow is reused in step S2;

[0040] S4, the remaining 1 / 10 of the first thickening underflow is filtered by vacuum filtration, and the filter cake is washed with distilled water during the filtration to obtain MHP product.

[0041] Example 3

[0042] A method for magnesium-activated precipitation of MHP, comprising the following steps:

[0043] S1, the red soil nickel ore manganese-removed liquid is mixed with a 10% by mass sodium hydroxide solution at a volume ratio of 10:100, and then subjected to precipitation reaction at a temperature of 65°C, a stirring speed of 1 r / min and a pressure of normal pressure for 5 min to obtain a precipitant;

[0044] S2, the precipitant obtained in step S1 is immediately mixed with the red soil nickel ore iron-aluminum-removed liquid, and then subjected to one-stage nickel-cobalt precipitation reaction at a pH value of 6.8 for 4 h to obtain one-stage nickel-cobalt precipitation slurry;

[0045] S3, the one-stage nickel-cobalt precipitation slurry obtained in step S2 is subjected to first thickening treatment to obtain first thickening underflow and first thickening overflow, wherein the first thickening overflow is subjected to two-stage nickel-cobalt precipitation reaction (pH value is 7.8) to obtain two-stage nickel-cobalt precipitation slurry, and the two-stage nickel-cobalt precipitation slurry is subjected to second thickening treatment to obtain second thickening overflow, and the second thickening overflow is subjected to manganese precipitation treatment (pH value is 10.0) to obtain red soil nickel ore manganese-removed liquid, and the red soil nickel ore manganese-removed liquid is reused in step S1; 9 / 10 of the first thickening underflow is reused in step S2;

[0046] S4, the remaining 1 / 10 of the first thickening underflow is filtered by vacuum filtration, and the filter cake is washed with distilled water during the filtration to obtain MHP product.

[0047] Comparative Example 1

[0048] The method for magnesium-activated precipitation of MHP in the present comparative example is basically the same as that in Example 1, except that in step S1, the precipitation reaction is performed for 1 min.

[0049] Comparative Example 2

[0050] The method for activating the magnesium precipitation MHP in the present comparative example is basically the same as that in Example 1, except that in step S1, the precipitation reaction is performed for 7 min.

[0051] Performance test

[0052] The nickel content, magnesium content and water content of the MHP products prepared in Examples 1-3 and Comparative Examples 1-2 were tested, and the results are shown in Table 1.

[0053] Table 1 Nickel content, magnesium content and water content of MHP products

[0054] As can be seen from the data in Table 1, the MHP products prepared by the method in Examples 1-3 have better quality (higher nickel content, lower magnesium content and lower water content); while in Comparative Examples 1 and 2, the precipitation reaction time is shorter or longer, and it is found that the quality of the prepared MHP products has decreased to some extent (the nickel content decreases, the magnesium content increases and the water content increases), which shows that by controlling the mixing reaction time of the magnesium solution and the sodium hydroxide solution in a specific range, MHP products with better quality can be prepared.

[0055] In summary, in the present application, by controlling the mixing reaction of the magnesium solution and the sodium hydroxide solution for 3-5 min, followed by a period of nickel-cobalt precipitation reaction, MHP products with high purity and quality can be obtained.

[0056] It should be noted that each of the above examples belongs to the same inventive concept, and each example has its own emphasis. If the description in an individual example is not exhaustive, the description in other examples can be referred to.

[0057] The above-described examples only express the embodiments of the present application, and the description is more specific and detailed, but it should not be construed as limiting the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application patent should be subject to the appended claims.

Claims

1. A method of magnesium-activated precipitated MHP, characterized by, The method comprises the following steps: S1, mixing a magnesium-containing solution with a sodium hydroxide solution, and then performing a precipitation reaction for 3-5 minutes to obtain a precipitant; S2, immediately mixing the precipitant with a solution after removing iron and aluminum from laterite nickel ore, and then performing a first-stage nickel-cobalt precipitation reaction to obtain a first-stage nickel-cobalt precipitation slurry; S3, performing a first thickening treatment on the first-stage nickel-cobalt precipitation slurry to obtain a first thickening underflow and a first thickening overflow; S4, performing a filtration treatment on the first thickening underflow to obtain an MHP product.

2. The method of magnesium-activated precipitated MHP according to claim 1, characterized in that, In step S1, the concentration of magnesium ions in the magnesium-containing solution is 4-6 g / L; the mass fraction of the sodium hydroxide solution is 10-13%; and the volume ratio of the magnesium-containing solution to the sodium hydroxide solution is (8-15):

100. The precipitation reaction further comprises: performing the precipitation reaction at a temperature of 50-65°C, a stirring speed of 1-2 r / min, and a normal pressure.

3. The method of magnesium-activated precipitated MHP according to claim 1, characterized in that, In step S2, the solution after removing iron and aluminum from laterite nickel ore comprises the following components: nickel 2-6 g / L, cobalt 0.1-0.5 g / L, manganese 2-3 g / L, and magnesium 4-10 g / L.

4. The method of magnesium-activated precipitated MHP according to claim 1, characterized in that, In step S2, the pH value of the first-stage nickel-cobalt precipitation reaction is 6.8-7.2, and the time is 4-6 hours.

5. The method of magnesium-activated precipitated MHP according to claim 1, characterized in that, In step S3, the method further comprises the following steps: performing a second-stage nickel-cobalt precipitation reaction on the first thickening overflow to obtain a second-stage nickel-cobalt precipitation slurry, then performing a second thickening treatment on the second-stage nickel-cobalt precipitation slurry to obtain a second thickening overflow, and then performing a manganese removal treatment on the second thickening overflow to obtain a solution after removing manganese from laterite nickel ore; The solution after removing manganese from laterite nickel ore is reused as a magnesium-containing solution.

6. The method of magnesium-activated precipitated MHP according to claim 5, characterized in that, The concentration of magnesium ions in the solution after removing manganese from laterite nickel ore is 4-6 g / L.

7. The method of magnesium-activated precipitated MHP according to claim 5, characterized in that, The pH value of the second-stage nickel-cobalt precipitation reaction is 7.8-8.

2.

8. The method of magnesium-activated precipitated MHP according to claim 5, characterized in that, The pH value of the manganese removal treatment is 10.0-10.

5.

9. The method of magnesium-activated, precipitated MHP of claim 1, wherein, In step S3, part of the first thickening underflow is reused in the first-stage nickel-cobalt precipitation reaction.

10. The method of magnesium-activated precipitated MHP according to claim 1, characterized in that, In step S4, the filtration treatment comprises vacuum filtration or pressure filtration, and the filter cake is washed with distilled water during the filtration.

Images