Hydroprocessing technology of laterite nickel ore

Abstract

The present invention provides a wet treatment process for laterite nickel ore. The wet treatment process comprises: step S1, using an inorganic acid to carry out acid leaching treatment on the laterite nickel ore to obtain a leached pulp; step S2, sequentially performing liquid-solid separation and countercurrent washing on the leached pulp to obtain a washed pulp and leached residue; step S3, adding a first oxidant and a first neutralizing agent to the washed pulp to carry out iron and aluminum removal treatment to obtain an iron and aluminum removal solution and iron and aluminum slag; step S4, precipitating nickel and cobalt on the iron and aluminum removal solution to obtain a precipitated pulp; step S5, continuously carrying out a dense separation treatment on the precipitated pulp to obtain an underflow and an overflow; step S6, sequentially performing a washing post-treatment on the underflow to obtain a nickel cobalt hydroxide product. The present invention provides a short-process laterite nickel ore wet treatment process, which reduces production costs and energy consumption, while improving the recovery rate of nickel and cobalt, the overall recovery rate of scandium and the quality of nickel and cobalt oxide products.

Description

Technical Field

[0001] The invention relates to the technical field of laterite nickel ore hydrometallurgy, and in particular to a hydrometallurgical process for laterite nickel ore. Background Art

[0002] At present, laterite nickel ore has become the main raw material in the EV battery industry chain, among which the high-pressure leaching process is the mainstream process for producing nickel-cobalt intermediate products. The main process is: leaching - pre-neutralization - two-stage iron and aluminum removal - two-stage nickel and cobalt precipitation - tailings neutralization. This process is mature and has been widely used by enterprises. However, the biggest problem with this process is:

[0003] (1) The process is long and requires two stages of iron and aluminum removal and two stages of nickel and cobalt precipitation. The purpose of the two stages of iron and aluminum removal is: the pH is controlled at a low level during the first stage of iron and aluminum removal, generally 3.8, in order to reduce the loss of nickel and cobalt, and the iron and aluminum slag is discharged from the system in an open circuit; the pH is controlled at 4.8 during the second stage of iron and aluminum removal, in order to precipitate the iron and aluminum cleanly and provide an iron-free and aluminum-free solution for subsequent nickel and cobalt recovery. The second stage of iron and aluminum slag has a high nickel and cobalt content, which is returned to the slurry after leaching to neutralize the residual acid to recover nickel and cobalt. The purpose of the two stages of nickel and cobalt precipitation is: the pH of the first stage of nickel and cobalt precipitation is controlled at a low level, as a nickel and cobalt hydroxide (MHP) product, and the pH of the second stage of nickel and cobalt precipitation is controlled at a high level, and all nickel and cobalt are precipitated and returned to the slurry after leaching to neutralize the residual acid to recover nickel and cobalt.

[0004] (2) The quality of MHP products is poor. The mass content of magnesium in MHP is generally about 1%~5%, and the mass content of manganese is about 5%~8%, which increases the complexity and cost of subsequent refining processes.

[0005] (3) Scandium is lost in the ferroaluminum slag, and its overall recovery rate is low.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] The main purpose of the present invention is to provide a wet treatment process for laterite nickel ore to solve the problems of long process, poor quality of nickel-cobalt hydroxide products and low overall recovery rate of scandium in the high-pressure leaching process of laterite nickel ore for precipitating nickel and cobalt in the prior art.

[0008] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a wet treatment process of laterite nickel ore is provided, and the laterite nickel ore includes limonite-type laterite nickel ore and / or residual ore-type laterite nickel ore, and the wet treatment process includes: step S1, using inorganic acid to carry out acid leaching treatment on the laterite nickel ore to obtain leached slurry; step S2, carrying out liquid-solid separation and countercurrent washing on the leached slurry in sequence to obtain washed slurry and leached slag; step S3, adding a first oxidant and a first neutralizing agent to the washed slurry to carry out iron and aluminum removal treatment to obtain an iron and aluminum removal solution and iron-aluminum slag; step S4, carrying out nickel-cobalt precipitation treatment on the iron and aluminum removal solution to obtain a precipitated slurry; step S5, continuously carrying out dense separation treatment on the precipitated slurry to obtain an underflow and an overflow; step S6, carrying out post-washing treatment on the underflow in sequence to obtain a nickel-cobalt hydroxide product; wherein the iron-aluminum slag is returned to the step of acid leaching treatment.

[0009] Furthermore, in the above step S3, the temperature of the iron-aluminum removal treatment is 25°C~100°C, the time of the iron-aluminum removal treatment is 0.5h~8h; and / or the endpoint pH value of the iron-aluminum removal treatment is 3.8~5.5; and / or the mass content of nickel in the iron-aluminum slag is 1%~8%, and the mass content of cobalt is 0.1%~0.9%.

[0010] Furthermore, in the above step S3, the first oxidant is selected from any one or more of a mixture of oxygen and sulfur dioxide, oxygen, ozone, persulfate, hydrogen peroxide, nitrite, and perchlorate, and / or the amount of the first oxidant added is 1.0 to 10.0 times the chemical reaction stoichiometric ratio of divalent iron in the washed slurry.

[0011] Furthermore, in the above step S3, the first neutralizing agent is selected from any one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, magnesium carbonate, magnesium bicarbonate, ammonium carbonate, ammonium bicarbonate, calcium oxide, magnesium oxide, sodium hydroxide, potassium hydroxide, ammonia water, calcium hydroxide, magnesium hydroxide, calcium carbonate, calcium bicarbonate, limestone, magnesia powder, magnesite, dolomite and marble.

[0012] Furthermore, in the above step S4, the temperature of the nickel-cobalt precipitation treatment is 25°C to 100°C, the time of the nickel-cobalt precipitation treatment is 0.5h to 8h; and / or the endpoint pH value of the nickel-cobalt precipitation treatment is 7.0 to 9.0.

[0013] Furthermore, in the above step S4, the process of precipitating nickel and cobalt treatment includes: directly adding a precipitant to the solution after iron and aluminum removal to precipitate nickel and cobalt treatment; or using a magnesium-containing solution to react with a precipitant to generate active magnesium hydroxide, and then adding the active magnesium hydroxide to the solution after iron and aluminum removal to precipitate nickel and cobalt treatment; and / or the precipitant is selected from any one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, magnesium carbonate, magnesium bicarbonate, ammonium carbonate, ammonium bicarbonate, calcium oxide, magnesium oxide, sodium hydroxide, potassium hydroxide, ammonia water, calcium hydroxide, magnesium hydroxide, calcium carbonate and calcium bicarbonate.

[0014] Furthermore, in the above step S1, the temperature of the acid leaching treatment is 90°C to 280°C, the time of the acid leaching treatment is 0.5h to 8h; and / or the end point acidity of the acid leaching treatment is 0.1g / L to 50g / L; and / or the pressure of the acid leaching treatment is 1MPa to 4MPa.

[0015] Furthermore, in the above step S1, the inorganic acid is selected from any one or more of sulfuric acid, hydrochloric acid and nitric acid.

[0016] Furthermore, in the above step S2, the liquid-solid separation method is thickener separation or filter press separation; and / or the countercurrent washing method is any one of multi-stage thickener series countercurrent washing, filter press on-machine countercurrent washing and slurry countercurrent washing.

[0017] Furthermore, in the above step S6, the post-washing treatment process includes sequentially performing an acidic solution washing treatment, an alkaline solution washing treatment and a nickel-cobalt-containing solution washing treatment.

[0018] Furthermore, in the above step S6, the amount of the acidic solution used for the acidic solution washing treatment is 0.01%~100% of the solid amount of the nickel cobalt hydroxide product; and / or the mass concentration of the acidic solution is 0.01wt%~5wt%, and the acidic solution is selected from any one or more of sulfuric acid solution, hydrochloric acid solution, nitric acid solution, carbonic acid solution and organic acid solution; and / or the temperature of the acidic solution washing treatment is 25°C~100°C, and the time of the acidic solution washing treatment is 0.5h~8h.

[0019] Furthermore, in the above step S6, the amount of alkaline solution used for the alkaline solution washing treatment is 0.01%~100% of the solid amount of the nickel cobalt hydroxide product; and / or the mass concentration of the alkaline solution is 0.1wt%~40wt%, and the alkaline solution is selected from one or more of sodium hydroxide solution, potassium hydroxide solution, ammonia water and carbonate solution; and / or the temperature of the alkaline solution washing treatment is 25°C~100°C, and the time of the alkaline solution washing treatment is 0.5h~8h.

[0020] Furthermore, in the above step S6, the mass of the nickel-cobalt solution used for the washing treatment of the nickel-cobalt solution is 0.01% to 100% of the solid mass of the nickel-cobalt hydroxide product; and / or the mass concentration of nickel and cobalt in the nickel-cobalt solution is 0.1 g / L to 100 g / L, and the nickel-cobalt solution is selected from any one or more of a leaching solution, a solution before iron and aluminum removal, a solution after iron and aluminum removal, and a self-prepared nickel-cobalt solution; and / or the temperature of the washing treatment of the nickel-cobalt solution is 25°C to 100°C, and the washing treatment time of the nickel-cobalt solution is 0.5h to 8h.

[0021] Furthermore, the wet treatment process further includes: returning part of the overflow to the countercurrent washing step; neutralizing the remaining part of the overflow with the leaching residue to obtain tailings slurry; the neutralization treatment temperature is 25°C~100°C, and / or the neutralization treatment time is 0.5h~8h; and / or the endpoint pH value of the neutralization treatment is 7.0~9.0.

[0022] Furthermore, a second oxidant and a second neutralizer are added during the above-mentioned neutralization treatment, and the second oxidant is selected from any one or more of a mixture of oxygen and sulfur dioxide, oxygen, ozone, persulfate, hydrogen peroxide, nitrite, and perchlorate; and / or the second neutralizer is selected from any one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, magnesium carbonate, magnesium bicarbonate, ammonium carbonate, ammonium bicarbonate, calcium oxide, magnesium oxide, sodium hydroxide, potassium hydroxide, ammonia water, calcium hydroxide, magnesium hydroxide, calcium carbonate, and calcium bicarbonate.

[0023] The technical solution of the present application is applied. The core of the present invention is to provide a short-process laterite nickel ore wet treatment process. Through acid leaching, liquid-solid separation and countercurrent washing, washed slurry and leached residue are obtained. The washed slurry is directly subjected to a de-ironization and aluminum removal to obtain a de-ironization and aluminum removal solution and iron-aluminum slag. The de-ironization and aluminum removal solution is directly subjected to a nickel-cobalt precipitation and post-treatment step. The iron-aluminum slag is returned to the acid leaching step, thereby achieving efficient enrichment of nickel and cobalt and quality improvement of nickel-cobalt hydroxide products. The advantage of the present application is that it shortens the complex process of traditional two-stage de-ironization and aluminum removal and two-stage nickel-cobalt precipitation, reduces production costs and energy consumption, and at the same time improves the recovery rate of nickel and cobalt, the overall recovery rate of scandium and the quality of nickel-cobalt oxide products. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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:

[0025] Figure 1 A flow chart of a laterite nickel ore wet treatment process according to Example 1 of the present invention is shown. DETAILED DESCRIPTION

[0026] 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.

[0027] As described in the background technology section, the existing technology of high-pressure leaching process of laterite nickel ore for precipitating nickel and cobalt has the problems of long process, poor quality of nickel and cobalt hydroxide products, and low overall recovery rate of scandium.

[0028] In order to solve the above problems, the present invention provides a wet treatment process of laterite nickel ore, wherein the laterite nickel ore includes limonite-type laterite nickel ore and / or residual ore-type laterite nickel ore, and the wet treatment process includes: step S1, acid leaching the laterite nickel ore with an inorganic acid to obtain a leached ore pulp; step S2, sequentially performing liquid-solid separation and countercurrent washing on the leached ore pulp to obtain a washed slurry and leached slag; step S3, adding a first oxidant and a first neutralizing agent to the washed slurry to perform iron and aluminum removal treatment to obtain an iron and aluminum removal solution and iron-aluminum slag; step S4, performing nickel-cobalt precipitation treatment on the iron and aluminum removal solution to obtain a precipitated slurry; step S5, continuously performing dense separation treatment on the precipitated slurry to obtain an underflow and an overflow; step S6, sequentially performing post-washing treatment on the underflow to obtain a nickel-cobalt hydroxide product; wherein the iron-aluminum slag is returned to the step of acid leaching treatment.

[0029] The core of the present invention is to provide a short-process laterite nickel ore wet treatment process, through acid leaching treatment, liquid-solid separation and countercurrent washing, to obtain washed slurry and leached residue, directly remove iron and aluminum from the washed slurry once, to obtain a solution after iron and aluminum removal and iron-aluminum slag, directly carry out a nickel-cobalt precipitation and post-treatment steps on the solution after iron and aluminum removal, and the iron-aluminum slag is returned to the acid leaching step, thereby achieving efficient enrichment of nickel and cobalt and quality improvement of nickel-cobalt hydroxide products. The advantage of the present application is that it shortens the complex process of traditional two-stage iron and aluminum removal and two-stage nickel-cobalt precipitation, reduces production costs and energy consumption, and at the same time improves the recovery rate of nickel and cobalt, the overall recovery rate of scandium and the quality of nickel-cobalt oxide products.

[0030] In addition, the ferroaluminum slag can be mixed with laterite nickel ore and then enter the autoclave for acid leaching treatment, or it can be entered into the autoclave alone. After the ferroaluminum slag is dissolved in the autoclave, nickel, cobalt and scandium enter the solution, and the iron and aluminum form alum and hematite respectively and precipitate into the slag.

[0031] In some embodiments of the present application, in the above step S3, the temperature of the iron-aluminum removal treatment is 25°C~100°C, the time of the iron-aluminum removal treatment is 0.5h~8h; and / or the endpoint pH value of the iron-aluminum removal treatment is 3.8~5.5; and / or, the mass content of nickel in the iron-aluminum slag is 1%~8%, and the mass content of cobalt is 0.1%~0.9%.

[0032] Although the present application has only one step of iron removal and aluminum treatment, the chemical reaction of iron removal and aluminum removal is promoted by controlling the conditions of iron removal and aluminum treatment such as temperature and time. The specific endpoint pH value range of the iron removal and aluminum treatment achieves the complete precipitation of iron and aluminum and the minimum dissolution of nickel and cobalt as much as possible, avoids unnecessary metal loss in subsequent treatment, and reduces the impact on the quality of nickel and cobalt hydroxide products. In addition, in order to further improve the overall efficiency and effect of the above iron removal and aluminum treatment, it is preferred that the temperature of the iron removal and aluminum treatment is 40°C~90°C, the time of the iron removal and aluminum treatment is 4h~6h, and the endpoint pH value of the iron removal and aluminum treatment is 4.5~5.5. Such optimized conditions are more helpful to minimize the nickel content and cobalt content included in the iron and aluminum slag. For example, the conditions of the iron removal and aluminum treatment in the present application make the mass content of nickel in the iron and aluminum slag 1%~6%, and the mass content of cobalt is 0.1%~0.8%, thereby minimizing the loss of nickel and cobalt in the one-step iron removal and aluminum treatment. In addition, the temperature of the iron and aluminum removal treatment can be 25°C, 30°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, and of course it can also be any point value in the range of 25°C~100°C, which will not be repeated here; the time of the iron and aluminum removal treatment can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h or 8h, and of course it can also be any point value in the range of 0.5h~8h, which will not be repeated here; the endpoint pH value of the iron and aluminum removal treatment can be 3.8, 4.0, 4.2, 4.5, 5.0, 5.2 or 5.5, and of course it can also be any point value in the range of 3.8~5.5, which will not be repeated here.

[0033] In some embodiments of the present application, in the above step S3, the first oxidant is selected from any one or more of a mixture of oxygen and sulfur dioxide, oxygen, ozone, persulfate, hydrogen peroxide, nitrite, and perchlorate, and / or the amount of the first oxidant added is 1.0 to 10.0 times the chemical reaction stoichiometric ratio of divalent iron in the washed slurry.

[0034] The selection and usage of the first oxidant (1.0 times to 10.0 times the chemical reaction stoichiometric ratio, preferably 5.0 times to 10.0 times the chemical reaction stoichiometric ratio) ensure that the divalent iron is oxidized to trivalent iron, thereby promoting the reaction of trivalent iron with the first neutralizer to form a precipitate. Excessive first oxidant can ensure that the divalent iron is completely oxidized, avoiding the divalent iron from causing pollution in subsequent processes or reducing the quality of nickel cobalt oxide products. At the same time, the present application prefers the above-mentioned rich variety and wide source of oxidants, which helps to adapt to different operating conditions and cost control, and provides more flexibility for the iron removal and aluminum treatment process. In addition, the amount of the first oxidant added can be 1.0 times, 2.0 times, 3.0 times, 4.0 times, 5.0 times, 6.0 times, 7.0 times, 8.0 times, 9.0 times or 10.0 times the chemical reaction stoichiometric ratio of the divalent iron in the washed slurry, and of course it can also be any point value within the range of 1.0 times to 10.0 times, which will not be repeated here.

[0035] In some embodiments of the present application, in the above step S3, the first neutralizing agent is selected from any one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, magnesium carbonate, magnesium bicarbonate, ammonium carbonate, ammonium bicarbonate, calcium oxide, magnesium oxide, sodium hydroxide, potassium hydroxide, ammonia water, calcium hydroxide, magnesium hydroxide, calcium carbonate, calcium bicarbonate, limestone, magnesia powder, magnesite, dolomite and marble.

[0036] The diverse selection of the first neutralizer enables iron and aluminum to be effectively precipitated under different pH and temperature conditions, while minimizing the impact on nickel and cobalt as much as possible. In addition, different first neutralizers can adapt to different leachate components and reaction environments, thereby helping to improve the recovery rate of metals such as nickel, cobalt, and scandium and reduce reagent consumption.

[0037] In some embodiments of the present application, in the above step S4, the temperature of the nickel-cobalt precipitation treatment is 25°C~100°C, the time of the nickel-cobalt precipitation treatment is 0.5h~8h; and / or the endpoint pH value of the nickel-cobalt precipitation treatment is 7.0~9.0.

[0038] The above optimized nickel-cobalt precipitation conditions are conducive to making nickel-cobalt be precipitated as completely as possible, while reducing the co-precipitation of impurities such as magnesium and manganese, and improving the purity and quality of nickel-cobalt hydroxide products. Reasonable control of the temperature and time of nickel-cobalt precipitation treatment is conducive to improving the efficiency of nickel-cobalt precipitation, and the specific endpoint pH value helps to separate nickel-cobalt from other impurities as accurately as possible, thereby reducing the complexity and cost of subsequent refining processes. Furthermore, it is preferred that the temperature of nickel-cobalt precipitation treatment is 40~90℃, and the time of nickel-cobalt precipitation treatment is 4~6h. In addition, the temperature of the precipitated nickel-cobalt treatment can be 25°C, 30°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, and of course it can also be any point value in the range of 25°C to 100°C, which will not be repeated here; the time of the precipitated nickel-cobalt treatment can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h or 8h, and of course it can also be any point value in the range of 0.5h to 8h, which will not be repeated here; the endpoint pH value of the precipitated nickel-cobalt treatment can be 7.0, 7.5, 8.0, 8.5 or 9.0, and of course it can also be any point value in the range of 7.0 to 9.0, which will not be repeated here.

[0039] In some embodiments of the present application, in the above step S4, the process of precipitating nickel and cobalt treatment includes: directly adding a precipitant to the solution after iron and aluminum removal to precipitate nickel and cobalt treatment; or using a magnesium-containing solution to first react with a precipitant to generate active magnesium hydroxide, and then adding the active magnesium hydroxide to the solution after iron and aluminum removal to precipitate nickel and cobalt treatment; and / or the precipitant is selected from any one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, magnesium carbonate, magnesium bicarbonate, ammonium carbonate, ammonium bicarbonate, calcium oxide, magnesium oxide, sodium hydroxide, potassium hydroxide, ammonia water, calcium hydroxide, magnesium hydroxide, calcium carbonate and calcium bicarbonate.

[0040] The two methods of precipitated nickel and cobalt treatment (direct precipitation and active magnesium hydroxide precipitation) improve the flexibility and efficiency of the precipitated nickel and cobalt treatment process. Among them, the method of directly adding a precipitant to precipitate nickel and cobalt is simpler and more direct, and is more suitable for situations where the nickel and cobalt concentration is high and the impurities are less. Although the method of converting the precipitant into active magnesium hydroxide precipitation in advance adds the conversion step, the active magnesium hydroxide precipitation is more suitable for improving the selectivity and efficiency of precipitation when the nickel and cobalt concentration is low or there are more impurities, and reducing the loss of nickel and cobalt. Among them, the magnesium-containing solution is preferably selected from any one or more of magnesium sulfate solution, magnesium nitrate solution and magnesium chloride solution, and the mass concentration of the magnesium-containing solution is preferably 0.1g / L~40g / L, such as the mass concentration of the magnesium-containing solution can be 0.1g / L, 0.5g / L, 1g / L, 3g / L, 5g / L, 10g / L, 15g / L, 20g / L, 25g / L, 30g / L, 35g / L or 40g / L, which will not be repeated here.

[0041] In some embodiments of the present application, in the above step S1, the temperature of the acid leaching treatment is 90°C~280°C, the time of the acid leaching treatment is 0.5h~8h; and / or the endpoint acidity of the acid leaching treatment is 0.1g / L~50g / L; and / or the pressure of the acid leaching treatment is 1MPa~4MPa.

[0042] The above optimized acid leaching conditions are conducive to improving the leaching rate of nickel and cobalt by acid leaching, reducing the consumption of acid, and controlling the properties of the leached slag. The temperature and time of the acid leaching treatment are conducive to improving the leaching efficiency, and the reasonable end point acidity is conducive to balancing the needs of nickel and cobalt leaching and subsequent treatment. The acid leaching treatment can be atmospheric leaching or high pressure leaching, and high pressure leaching is more preferably used to improve the leaching efficiency of nickel and cobalt. The laterite nickel ore treated by acid leaching can be either limonite-type laterite nickel ore, residual ore-type laterite nickel ore, or mixed ore in any proportion. Limonite-type laterite nickel ore and residual ore-type laterite nickel ore can be mixed into the autoclave or can be separately entered into the autoclave one after another. Further, in the preferred acid leaching process, the acid-ore ratio is 200kg / t ore~400kg / t ore, preferably 250kg / t ore~350kg / t ore, so as to help take into account the acid leaching efficiency and reduce the improper waste of acid as much as possible. Further, it is preferred that the acid leaching temperature is 200° C. to 280° C., the acid leaching time is 1 h to 8 h, the end point acidity of the acid leaching is 5 g / L to 30 g / L, and the acid leaching pressure is 3 to 4 MPa. In addition, the temperature of the acid leaching treatment can be 90°C, 100°C, 120°C, 140°C, 150°C, 170°C, 190°C, 200°C, 210°C, 210°C, 220°C, 230°C, 250°C, 255°C, 260°C, 265°C, 270°C, 275°C or 280°C, and of course it can also be any point value in the range of 90°C to 280°C, which will not be repeated here; the time of the acid leaching treatment can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h or 8h, and of course it can also be any point value in the range of 0.5h to 8h, which will not be repeated here; the endpoint acidity of the acid leaching treatment can be The acid-ore ratio can be 0.1g / L, 0.5g / L, 1g / L, 2g / L, 3g / L, 4g / L, 5g / L, 6g / L, 8g / L, 10g / L, 12g / L, 15g / L, 20g / L, 22g / L, 25g / L, 28g / L, 30g / L, 35g / L, 40g / L, 45g / L or 50g / L. Of course, it can also be any point value within the range of 0.1g / L~50g / L, which will not be repeated here. The acid-ore ratio can be 200kg / t ore, 220kg / t ore, 250kg / t ore, 255kg / t ore, 280kg / t ore, 300kg / t ore, 320kg / t ore, 350kg / t ore or 400kg / t ore, which will not be repeated here.

[0043] In some embodiments of the present application, in the above step S1, the inorganic acid is selected from any one or more of sulfuric acid, hydrochloric acid and nitric acid.

[0044] Acid leaching is performed using sulfuric acid, hydrochloric acid or nitric acid. These inorganic acids have strong leaching capacity and are conducive to efficiently extracting nickel and cobalt from laterite nickel ore. Furthermore, the inorganic acid is preferably sulfuric acid, which can further recover sulfate ions, achieve recycling, and reduce production costs.

[0045] In some embodiments of the present application, in the above step S2, the liquid-solid separation method is thickener separation or filter press separation; and / or the countercurrent washing method is any one of multi-stage thickener series countercurrent washing, filter press on-machine countercurrent washing and slurry countercurrent washing.

[0046] The selection of liquid-solid separation and countercurrent washing methods (thickener, filter press, multi-stage thickener in series with countercurrent washing, etc.) further improves the effect of countercurrent washing, reduces the acidity in the leaching residue, recovers nickel and cobalt in the solution, and reduces resource waste.

[0047] In some embodiments of the present application, in the above step S6, the post-washing treatment process includes acidic solution washing treatment, alkaline solution washing treatment and nickel-cobalt containing solution washing treatment performed in sequence.

[0048] The above post-washing treatment conditions and the sequential steps of acidic solution washing treatment, alkaline solution washing treatment and nickel-cobalt solution washing treatment further optimize the purity of the nickel-cobalt hydroxide product, and improve the market competitiveness of the acidic solution washing treatment, alkaline solution washing treatment and nickel-cobalt solution washing treatment products by gradually removing impurities.

[0049] In some embodiments of the present application, in the above step S6, the amount of acidic solution used for the acidic solution washing treatment is 0.01%~100% of the solid amount of the nickel cobalt hydroxide product; and / or the mass concentration of the acidic solution is 0.01wt%~5wt%, and the acidic solution is selected from any one or more of sulfuric acid solution, hydrochloric acid solution, nitric acid solution, carbonic acid solution and organic acid solution; and / or the temperature of the acidic solution washing treatment is 25℃~100℃, and the time of the acidic solution washing treatment is 0.5h~8h.

[0050] The above preferred acid solution washing treatment conditions and the selection of the amount of acid solution improve the removal rate of impurity magnesium in nickel cobalt hydroxide products. Reasonable acid solution concentration and consumption can effectively dissolve impurity magnesium without excessively dissolving nickel and cobalt, reducing the risk of reduced quality of nickel cobalt hydroxide products. Further, the amount of acid solution used for acid solution washing treatment is preferably 0.1% to 5% of the solid amount of nickel cobalt hydroxide product, such as 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, and of course it can be any point value within the range of 0.1% to 5%, which will not be repeated here. In order to further improve the efficiency and effect of acid solution washing treatment, the temperature of acid solution washing treatment is preferably 50°C to 80°C, and the time of acid solution washing treatment is 4 to 6h. In addition, the temperature of the acid solution washing treatment can be 25°C, 30°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, and of course, it can also be any point value within the range of 25°C to 100°C, which will not be repeated here; the time of the acid solution washing treatment can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7. 5h or 8h, of course, it can also be any point value in the range of 0.5h~8h, which is not repeated here; the mass concentration of the acidic solution can be 0.01wt%, 0.02wt%, 0.05wt%, 0.08wt%, 0.1wt%, 0.3wt%, 0.5wt%, 1wt%, 1.2wt%, 1.5wt%, 1.8wt%, 2.0wt%, 2.5wt%, 3.0wt%, 3.5wt%, 4.0wt%, 4.5wt% or 5wt%, which is not repeated here.

[0051] In some embodiments of the present application, in the above step S6, the amount of alkaline solution used for the alkaline solution washing treatment is 0.01%~100% of the solid amount of the nickel cobalt hydroxide product; and / or the mass concentration of the alkaline solution is 0.1wt%~40wt%, and the alkaline solution is selected from one or more of sodium hydroxide solution, potassium hydroxide solution, ammonia water and carbonate solution; and / or the temperature of the alkaline solution washing treatment is 25℃~100℃, and the time of the alkaline solution washing treatment is 0.5h~8h.

[0052] The conditions of alkaline solution washing treatment and the selection of alkaline substances improve the removal rate of impurities manganese and sulfate ions in nickel cobalt hydroxide products. Specific alkaline conditions can promote the dissolution and separation of manganese without affecting the stability of nickel cobalt, thereby improving the purity of nickel cobalt hydroxide products. Further, it is preferred that the amount of alkaline solution used for alkaline solution washing treatment is 0.1% to 5% of the solid amount of nickel cobalt hydroxide product, such as 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, and of course it can be any point value within the range of 0.1% to 5%, which will not be repeated here. In order to further improve the efficiency and effect of alkaline solution washing treatment, it is preferred that the temperature of alkaline solution washing treatment is 50°C to 80°C, and the time of alkaline solution washing treatment is 4 to 6 hours. In addition, the temperature of the alkaline solution washing treatment can be 25°C, 30°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, and of course it can be any point value in the range of 25°C to 100°C, which will not be repeated here; the time of the alkaline solution washing treatment can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h or 8h, and of course it can be any point value in the range of 0.5h to 8h, which will not be repeated here; the mass concentration of the alkaline solution can be 0.1wt%, 0.5wt%, 1wt%, 3wt%, 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt% or 40wt%, which will not be repeated here.

[0053] In some embodiments of the present application, in the above step S6, the mass of the nickel-cobalt solution used for the washing treatment of the nickel-cobalt solution is 0.01%~100% of the solid mass of the nickel-cobalt hydroxide product; and / or the mass concentration of nickel and cobalt in the nickel-cobalt solution is 0.1g / L~100g / L, and the nickel-cobalt solution is selected from any one or more of a leaching solution, a solution before iron and aluminum removal, a solution after iron and aluminum removal, and a self-prepared nickel-cobalt solution; and / or the temperature of the washing treatment of the nickel-cobalt solution is 25°C~100°C, and the washing treatment time of the nickel-cobalt solution is 0.5h~8h.

[0054] The conditions for washing the nickel-cobalt solution and the selection of the nickel-cobalt content in the nickel-cobalt solution are helpful to supplement the loss of nickel-cobalt in the washing process, and at the same time, the impurities such as magnesium ions and manganese ions are further removed by washing the nickel-cobalt solution to ensure the quality of the nickel-cobalt hydroxide product. Using the leaching solution, the solution before iron and aluminum removal, and the solution after iron and aluminum removal as the source of the nickel-cobalt solution is helpful to improve the recycling of these solutions, and to reduce the loss of nickel and cobalt, and improve the overall recovery rate of nickel and cobalt. Further, it is preferred that the amount of the nickel-cobalt solution used for washing the nickel-cobalt solution is 0.1% to 5% of the solid amount of the nickel-cobalt hydroxide product, such as 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, and of course it can also be any point value within the range of 0.1% to 5%, which will not be repeated here. In order to further improve the efficiency and effect of the washing treatment of the nickel-cobalt solution, it is preferred that the temperature of the washing treatment of the nickel-cobalt solution is 50°C to 80°C, and the time of the washing treatment of the nickel-cobalt solution is 4 to 6h. In addition, the temperature of the nickel-cobalt solution washing treatment can be 25°C, 30°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, and of course it can be any point value within the range of 25°C to 100°C, which will not be repeated here; the time of the nickel-cobalt solution washing treatment can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h or 8h , of course, it can also be any point value in the range of 0.5h~8h, which will not be repeated here; the mass concentration of nickel and cobalt in the nickel-cobalt containing solution is 0.1g / L, 1g / L, 3g / L, 5g / L, 10g / L, 15g / L, 20g / L, 25g / L, 30g / L, 35g / L, 40g / L, 45g / L, 50g / L, 55g / L, 60g / L, 65g / L, 70g / L, 75g / L, 80g / L, 85g / L, 90g / L, 95g / L or 100g / L, which will not be repeated here.

[0055] In some embodiments of the present application, the above-mentioned wet treatment process also includes: returning part of the overflow to the countercurrent washing step; neutralizing the remaining part of the overflow with the leaching residue to obtain tailings slurry; the neutralization treatment temperature is 25°C~100°C, and / or the neutralization treatment time is 0.5h~8h; and / or the endpoint pH value of the neutralization treatment is 7.0~9.0.

[0056] The recycling of overflow (return countercurrent washing) and the neutralization treatment of the remaining part (neutralization with leaching residue) realize the reuse of resources and reduce waste emissions. At the same time, the environmental protection and resource utilization of tailings slurry are improved through neutralization treatment. Furthermore, the preferred neutralization treatment temperature is 50°C~80°C, and the preferred neutralization treatment time is 4h~6h. In addition, the temperature of the neutralization treatment can be 25°C, 30°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, and of course it can also be any point value in the range of 25°C~100°C, which will not be repeated here; the time of the neutralization treatment can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h or 8h, and of course it can also be any point value in the range of 0.5h~8h, which will not be repeated here; the endpoint pH value of the neutralization treatment can be 7.0, 7.5, 8.0, 8.5 or 9.0, and of course it can also be any point value in the range of 7.0~9.0, which will not be repeated here.

[0057] In some embodiments of the present application, a second oxidant and a second neutralizer are added during the above-mentioned neutralization treatment, and the second oxidant is selected from any one or more of a mixture of oxygen and sulfur dioxide, oxygen, ozone, persulfate, hydrogen peroxide, nitrite, and perchlorate; and / or the second neutralizer is selected from any one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, magnesium carbonate, magnesium bicarbonate, ammonium carbonate, ammonium bicarbonate, calcium oxide, magnesium oxide, sodium hydroxide, potassium hydroxide, ammonia water, calcium hydroxide, magnesium hydroxide, calcium carbonate, and calcium bicarbonate.

[0058] The use of the second oxidant and the second neutralizer in the neutralization treatment further optimizes the tailings treatment process, ensures the complete precipitation of residual metals, reduces environmental pollution, and at the same time realizes the resource utilization of tailings by selecting the appropriate second oxidant and the second neutralizer.

[0059] The precipitation method of the present invention is used for limonite-type laterite nickel ore, and the mass content of nickel in the limonite-type laterite nickel ore is preferably 0.8% to 1.8%, the mass content of cobalt is 0.01% to 0.5%, the mass content of iron is 40% to 50%, the mass content of magnesium is 1% to 10%, the mass content of manganese is 0.1% to 1.5%, and the mass content of scandium is 10 to 80 ppm.

[0060] Further, the mass content of nickel in the nickel cobalt hydroxide product obtained by the wet treatment process of the above laterite nickel ore is 39%~45.5%, the mass content of cobalt is 3.1%~4.6%, the mass content of scandium is 1100ppm~1400ppm, the mass content of magnesium is 0.15%~0.25%, and the mass content of manganese is 0.4%~0.9%, with excellent quality. The recovery rate of nickel in the overall process is 88%~95.5%, the recovery rate of cobalt is 85%~95%, and the recovery rate of scandium is 83%~96%. It can be seen that the advantage of the wet treatment process of laterite nickel ore in this application is not only to shorten the complex process of traditional two-stage iron removal and two-stage nickel cobalt precipitation, but also to reduce production costs and energy consumption, while improving the recovery rate of nickel cobalt, the overall recovery rate of scandium, and significantly reducing the content of magnesium and manganese in the nickel cobalt hydroxide product, thereby greatly improving the quality of the nickel cobalt oxide product.

[0061] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0062] Example 1

[0063] The raw material is limonite-type laterite nickel ore, with a nickel content of 1.2%, a cobalt content of 0.12%, an iron content of 45%, a magnesium content of 2%, a manganese content of 0.5%, and a scandium content of 40ppm. Figure 1 The flow chart of the wet treatment process of laterite nickel ore is shown, in which the limonite-type laterite nickel ore is subjected to high-pressure acid leaching, the acid-ore ratio is 250kg / t ore, the acid leaching temperature is 255°C, the acid leaching time is 1h, iron-aluminum slag is injected, the end point acidity is 5g / L, and the leached slurry is obtained.

[0064] After the leached pulp is subjected to liquid-solid separation, it is subjected to countercurrent washing with a seven-stage CCD thickener to obtain washed pulp and leached slag. After that, the washed pulp is treated with limestone and oxygen to remove iron and aluminum. The amount of oxygen added is 5.0 times the chemical reaction stoichiometric ratio of divalent iron in the washed pulp. The temperature of the iron and aluminum removal treatment is 40°C, the time of the iron and aluminum removal treatment is 3h, and the end point pH of the iron and aluminum removal treatment is controlled to 5.0 to obtain a solution after iron and aluminum removal and iron and aluminum slag. The mass content of nickel in the iron and aluminum slag is 3%, and the mass content of cobalt is 0.5%.

[0065] The obtained iron-aluminum slag is returned to the above high-pressure acid leaching step. After the iron-aluminum removal, magnesium oxide is added to the liquid to precipitate nickel and cobalt. The temperature of the precipitation of nickel and cobalt is 40°C, the time of the precipitation of nickel and cobalt is 3 hours, and the endpoint pH of the precipitation of nickel and cobalt is controlled to 8.5 to obtain a precipitation slurry.

[0066] The precipitated slurry is continuously subjected to a dense separation treatment to obtain an underflow and an overflow;

[0067] The underflow is subjected to post-washing treatments including acidic solution washing treatment, alkaline solution washing treatment and nickel-cobalt-containing solution washing treatment in sequence using 0.5wt% sulfuric acid solution, 5wt% sodium hydroxide solution and nickel-cobalt-containing solution with a mass concentration of 3g / L to obtain a nickel-cobalt hydroxide product, wherein the masses of the sulfuric acid solution, the sodium hydroxide solution and the nickel-cobalt-containing solution are each independently 5% of the solid mass of the nickel-cobalt hydroxide product, the temperatures of the acidic solution washing treatment, the alkaline solution washing treatment and the nickel-cobalt-containing solution washing treatment are each independently 60°C, and the time is each independently 3h.

[0068] After testing, the mass content of nickel in nickel cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.2%, and the mass content of manganese is 0.5%, with excellent quality. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0069] Example 2

[0070] The only difference between this embodiment and embodiment 1 is that the endpoint pH value of the iron and aluminum removal treatment is 4.5, and the iron and aluminum removal solution and iron-aluminum slag are obtained. The mass content of nickel in the iron-aluminum slag is 2.5%, and the mass content of cobalt is 0.3%, and nickel cobalt hydroxide is finally obtained. After testing, the mass content of nickel in the nickel cobalt hydroxide is 44%, the mass content of cobalt is 3.7%, the mass content of scandium is 1300ppm, the mass content of magnesium is 0.2%, and the mass content of manganese is 0.5%, and the quality is excellent. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0071] Example 3

[0072] The only difference between this embodiment and embodiment 1 is that the endpoint pH value of the iron and aluminum removal treatment is 5.5, and the iron and aluminum removal solution and iron-aluminum slag are obtained. The mass content of nickel in the iron-aluminum slag is 8%, and the mass content of cobalt is 0.9%, and nickel cobalt hydroxide is finally obtained. After testing, the mass content of nickel in the nickel cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.2%, and the mass content of manganese is 0.5%, and the quality is excellent. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0073] Example 4

[0074] The only difference between this embodiment and embodiment 1 is that the endpoint pH value of the iron and aluminum removal treatment is 3.8, and the iron and aluminum removal solution and iron-aluminum slag are obtained. The mass content of nickel in the iron-aluminum slag is 3%, and the mass content of cobalt is 0.3%, and nickel cobalt hydroxide is finally obtained. After testing, the mass content of nickel in the nickel cobalt hydroxide is 42%, the mass content of cobalt is 3.1%, the mass content of scandium is 1100ppm, the mass content of magnesium is 0.2%, and the mass content of manganese is 0.5%, and the quality is excellent. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0075] Example 5

[0076] The only difference between this embodiment and embodiment 1 is that the temperature of the iron and aluminum removal treatment is 90°C, and the iron and aluminum removal solution and iron-aluminum slag are obtained. The mass content of nickel in the iron-aluminum slag is 2.8%, and the mass content of cobalt is 0.45%, and nickel cobalt hydroxide is finally obtained. After testing, the mass content of nickel in the nickel cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.2%, and the mass content of manganese is 0.5%, and the quality is excellent. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0077] Example 6

[0078] The only difference between this embodiment and embodiment 1 is that the temperature of the iron and aluminum removal treatment is 25°C, and the iron and aluminum removal solution and iron-aluminum slag are obtained. The mass content of nickel in the iron-aluminum slag is 3.6%, and the mass content of cobalt is 0.55%, and nickel cobalt hydroxide is finally obtained. After testing, the mass content of nickel in the nickel cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.2%, and the mass content of manganese is 0.5%, and the quality is excellent. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0079] Example 7

[0080] The only difference between this embodiment and embodiment 1 is that the time for iron and aluminum removal treatment is 6 hours, and the solution after iron and aluminum removal and iron-aluminum slag are obtained. The mass content of nickel in the iron-aluminum slag is 3.1%, and the mass content of cobalt is 0.55%, and nickel cobalt hydroxide is finally obtained. After testing, the mass content of nickel in nickel cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.2%, and the mass content of manganese is 0.5%, and the quality is excellent. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0081] Example 8

[0082] The only difference between this embodiment and embodiment 1 is that the time for iron and aluminum removal treatment is 4 hours, and the solution after iron and aluminum removal and iron-aluminum slag are obtained. The mass content of nickel in the iron-aluminum slag is 3.05%, and the mass content of cobalt is 0.52%, and nickel cobalt hydroxide is finally obtained. After testing, the mass content of nickel in nickel cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.2%, and the mass content of manganese is 0.5%, and the quality is excellent. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0083] Example 9

[0084] The only difference between this embodiment and embodiment 1 is that the amount of oxygen added is 10.0 times the chemical reaction stoichiometric ratio of the divalent iron in the washed slurry, and a solution after iron and aluminum removal and iron-aluminum slag are obtained. The mass content of nickel in the iron-aluminum slag is 2.95%, and the mass content of cobalt is 0.45%, and nickel cobalt hydroxide is finally obtained. After testing, the mass content of nickel in nickel cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.2%, and the mass content of manganese is 0.5%, and the quality is excellent. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0085] Example 10

[0086] The only difference between this embodiment and embodiment 1 is that the amount of oxygen added is 1.0 times the chemical reaction stoichiometric ratio of the divalent iron in the washed slurry, and a solution after iron and aluminum removal and iron-aluminum slag are obtained. The mass content of nickel in the iron-aluminum slag is 3.2%, and the mass content of cobalt is 0.52%, and nickel cobalt hydroxide is finally obtained. After testing, the mass content of nickel in nickel cobalt hydroxide is 40.5%, the mass content of cobalt is 3.1%, the mass content of scandium is 1100ppm, the mass content of magnesium is 0.2%, and the mass content of manganese is 0.5%, and the quality is excellent. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0087] Embodiment 11

[0088] This embodiment is different from embodiment 1 only in that potassium persulfate and potassium carbonate are used as the first oxidant and the first neutralizer, respectively, to obtain a solution after iron and aluminum removal and iron-aluminum slag, the mass content of nickel in the iron-aluminum slag is 2.95%, and the mass content of cobalt is 0.45%, and nickel cobalt hydroxide is finally obtained. After testing, the mass content of nickel in nickel cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.2%, and the mass content of manganese is 0.5%, with excellent quality. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0089] Example 12

[0090] The only difference between this embodiment and embodiment 1 is that the endpoint pH of the precipitated nickel-cobalt treatment is controlled to 9.0, a precipitated slurry is obtained, and finally nickel-cobalt hydroxide is obtained. After testing, the mass content of nickel in the nickel-cobalt hydroxide is 39%, the mass content of cobalt is 3.7%, the mass content of scandium is 1100ppm, the mass content of magnesium is 0.9%, and the mass content of manganese is 0.9%, and the quality is excellent. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0091] Example 13

[0092] The only difference between this embodiment and embodiment 1 is that the endpoint pH of the precipitated nickel-cobalt treatment is controlled to 7.0, a precipitated slurry is obtained, and finally nickel-cobalt hydroxide is obtained. After testing, the mass content of nickel in the nickel-cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.2%, and the mass content of manganese is 0.5%, and the quality is excellent. The recovery rate of nickel in the overall process is 88%, the recovery rate of cobalt is 85%, and the recovery rate of scandium is 83%.

[0093] Embodiment 14

[0094] The only difference between this embodiment and embodiment 1 is that the temperature of the nickel-cobalt precipitation treatment is 90°C to obtain a precipitated slurry, and finally obtain nickel-cobalt hydroxide. After testing, the mass content of nickel in the nickel-cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.15%, and the mass content of manganese is 0.4%, with excellent quality. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0095] Embodiment 15

[0096] The only difference between this embodiment and embodiment 1 is that the temperature of the precipitated nickel-cobalt treatment is 25°C, a precipitated slurry is obtained, and finally nickel-cobalt hydroxide is obtained. After testing, the mass content of nickel in the nickel-cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.25%, and the mass content of manganese is 0.55%, and the quality is excellent. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0097] Example 16

[0098] The only difference between this embodiment and embodiment 1 is that the treatment time of precipitated nickel and cobalt is 6 hours, and a precipitated slurry is obtained, and finally nickel cobalt hydroxide is obtained. After testing, the mass content of nickel in nickel cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.15%, and the mass content of manganese is 0.45%, and the quality is excellent. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0099] Embodiment 17

[0100] The only difference between this embodiment and embodiment 1 is that the treatment time of precipitated nickel and cobalt is 4 hours, and a precipitated slurry is obtained, and finally nickel cobalt hydroxide is obtained. After testing, the mass content of nickel in nickel cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.17%, and the mass content of manganese is 0.48%, and the quality is excellent. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0101] Embodiment 18

[0102] The only difference between this embodiment and embodiment 1 is that the raw material is limonite-type laterite nickel ore, the mass content of nickel is 0.9%, the mass content of cobalt is 0.1%, the mass content of iron is 45%, the mass content of scandium is 60ppm, the mass content of magnesium is 1.5%, and the mass content of manganese is 0.8%. After high-pressure acid leaching treatment, the acid-ore ratio is 250kg / t ore, the acid leaching temperature is 255℃, the acid leaching time is 1h, iron-aluminum slag is added, the end point acidity is 5g / L, and the leached ore pulp is obtained.

[0103] After the leached pulp is subjected to liquid-solid separation, it is subjected to countercurrent washing with a seven-stage CCD thickener to obtain washed pulp and leached slag. Then, the washed pulp is treated with limestone and potassium persulfate to remove iron and aluminum. The amount of potassium persulfate added is 5.0 times the chemical reaction stoichiometric ratio of divalent iron in the washed pulp. The temperature of the iron and aluminum removal treatment is 40°C, the time of the iron and aluminum removal treatment is 3h, and the end point pH of the iron and aluminum removal treatment is controlled to 5.0 to obtain a solution after iron and aluminum removal and iron and aluminum slag. The mass content of nickel in the iron and aluminum slag is 3%, and the mass content of cobalt is 0.5%.

[0104] The obtained iron-aluminum slag is returned to the above-mentioned high-pressure acid leaching treatment step. A 3g / L magnesium-containing solution is reacted with magnesium oxide to generate active magnesium hydroxide. After the iron and aluminum are removed, the active magnesium hydroxide is added to the liquid to precipitate nickel and cobalt. The temperature of the precipitated nickel and cobalt treatment is 40°C, the time of the precipitated nickel and cobalt treatment is 3h, and the endpoint pH of the precipitated nickel and cobalt treatment is controlled to 8.5 to obtain a precipitated slurry, and finally nickel hydroxide is obtained. After testing, the mass content of nickel in nickel cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.2%, and the mass content of manganese is 0.5%, with excellent quality. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0105] Embodiment 19

[0106] The only difference between this embodiment and embodiment 1 is that the raw material is limonite-type laterite nickel ore, the mass content of nickel is 1.2%, the mass content of iron is 45%, and the mass content of magnesium is 2%. After high-pressure acid leaching, the acid-ore ratio is 350kg / t ore, the temperature of the acid leaching treatment is 280°C, the time of the acid leaching treatment is 8h, iron-aluminum slag is driven in, the end point acidity is 30g / L, and the leached ore pulp is obtained, and nickel hydroxide is finally obtained. After testing, the mass content of nickel in nickel cobalt hydroxide is 45%, the mass content of cobalt is 4%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.2%, and the mass content of manganese is 0.5%, with excellent quality. The recovery rate of nickel in the overall process is 95.5%, the recovery rate of cobalt is 95%, and the recovery rate of scandium is 96%.

[0107] Embodiment 20

[0108] The only difference between this embodiment and embodiment 1 is that: 5wt% sulfuric acid solution, 40wt% sodium hydroxide solution, and nickel-cobalt-containing solution with a mass concentration of 50g / L are used to sequentially wash the bottom flow with an acidic solution, an alkaline solution, and a nickel-cobalt-containing solution to obtain a nickel-cobalt hydroxide product, wherein the amount of sulfuric acid solution, sodium hydroxide solution, and nickel-cobalt-containing solution is independently 1% of the solid amount of the nickel-cobalt hydroxide product, and the temperature of the acidic solution washing, the alkaline solution washing, and the nickel-cobalt-containing solution washing is independently 80°C, and the time is independently 6h. After testing, the mass content of nickel in nickel-cobalt hydroxide is 45.5%, the mass content of cobalt is 4.6%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.17%, and the mass content of manganese is 0.45%, with excellent quality. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0109] Embodiment 21

[0110] The only difference between this embodiment and embodiment 1 is that: 0.4wt% sulfuric acid solution, 4wt% sodium hydroxide solution, and nickel-cobalt-containing solution with a mass concentration of 2g / L are used to sequentially wash the bottom flow with an acidic solution, an alkaline solution, and a nickel-cobalt-containing solution to obtain a nickel-cobalt hydroxide product, wherein the amount of sulfuric acid solution, sodium hydroxide solution, and nickel-cobalt-containing solution is independently 3% of the solid amount of the nickel-cobalt hydroxide product, and the temperature of the acidic solution washing, the alkaline solution washing, and the nickel-cobalt-containing solution washing is independently 50°C, and the time is independently 4h. After testing, the mass content of nickel in nickel-cobalt hydroxide is 44.5%, the mass content of cobalt is 3.8%, the mass content of scandium is 1400ppm, the mass content of magnesium is 0.25%, and the mass content of manganese is 0.53%, with excellent quality. The recovery rate of nickel in the overall process is 95%, the recovery rate of cobalt is 94.5%, and the recovery rate of scandium is 96%.

[0111] Comparative Example 1

[0112] The raw material is limonite-type laterite nickel ore, with a nickel content of 1.2%, an iron content of 45%, and a magnesium content of 2%. After high-pressure acid leaching, the acid-ore ratio is 250kg / t ore, the acid leaching temperature is 255℃, the acid leaching time is 1h, and iron-aluminum slag is added. The end point acidity is 30g / L to obtain the leached ore pulp.

[0113] After leaching, the slurry is subjected to seven-stage CCD thickener countercurrent washing, one-stage iron and aluminum removal treatment, two-stage iron and aluminum removal treatment, one-stage nickel and cobalt precipitation treatment, and two-stage nickel and cobalt precipitation treatment in sequence. The washing treatment obtains nickel and cobalt hydroxide, wherein limestone is used for the first-stage iron and aluminum removal treatment, the temperature of the first-stage iron and aluminum removal treatment is 80°C, the time is 4 hours, and the endpoint pH is controlled at 3.8; limestone is used for the second-stage iron and aluminum removal treatment, the temperature of the second-stage iron and aluminum removal treatment is 70°C, the time is 4 hours, and the endpoint pH is controlled at 4.8; sodium hydroxide is used for the first-stage nickel and cobalt precipitation treatment, the temperature of the first-stage nickel and cobalt precipitation treatment is 60°C, the time is 3 hours, and the endpoint pH is controlled at 7.8; sodium hydroxide is used for the second-stage nickel and cobalt precipitation treatment, the temperature of the second-stage nickel and cobalt precipitation treatment is 50°C, the time is 3 hours, and the endpoint pH is controlled at 8.4.

[0114] After testing, the mass content of nickel in nickel cobalt hydroxide is 39%, the mass content of cobalt is 3.5%, the mass content of scandium is 300ppm, the mass content of magnesium is 1.5%, and the mass content of manganese is 6%, with excellent quality. The recovery rate of nickel in the overall process is 91%, the recovery rate of cobalt is 90%, and the recovery rate of scandium is 25%.

[0115] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0116] The core of the present invention is to provide a short-process laterite nickel ore wet treatment process, through acid leaching treatment, liquid-solid separation and countercurrent washing, to obtain washed slurry and leached residue, directly remove iron and aluminum from the washed slurry once, to obtain a solution after iron and aluminum removal and iron-aluminum slag, directly carry out a nickel-cobalt precipitation and post-treatment steps on the solution after iron and aluminum removal, and the iron-aluminum slag is returned to the acid leaching step, thereby achieving efficient enrichment of nickel and cobalt and quality improvement of nickel-cobalt hydroxide products. The advantage of the present application is that it shortens the complex process of traditional two-stage iron and aluminum removal and two-stage nickel-cobalt precipitation, reduces production costs and energy consumption, and at the same time improves the recovery rate of nickel and cobalt, the overall recovery rate of scandium and the quality of nickel-cobalt oxide products.

[0117] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A wet treatment process for laterite nickel ore, wherein the laterite nickel ore comprises limonite-type laterite nickel ore and / or residual ore-type laterite nickel ore, characterized in that: The wet treatment process comprises: Step S1, acid leaching the laterite nickel ore with an inorganic acid to obtain a leached slurry; Step S2, sequentially subjecting the leached pulp to liquid-solid separation and countercurrent washing to obtain washed pulp and leached residue; Step S3, adding a first oxidant and a first neutralizer to the washed slurry to perform iron and aluminum removal treatment to obtain an iron and aluminum removed solution and iron and aluminum slag; Step S4, performing nickel and cobalt precipitation treatment on the solution after iron and aluminum removal to obtain a precipitation slurry; Step S5, continuously performing a thickening and separation treatment on the precipitated slurry to obtain an underflow and an overflow; Step S6, washing and post-processing the underflow in sequence to obtain a nickel cobalt hydroxide product; wherein the iron-aluminum slag is returned to the acid leaching step; The endpoint pH value of the iron and aluminum removal treatment is 3.8-5.5; The mass content of nickel in the ferroaluminum slag is 1% to 8%, and the mass content of cobalt is 0.1% to 0.9%.

2. The wet treatment process of laterite nickel ore according to claim 1, characterized in that: In the step S3, the temperature of the iron and aluminum removal treatment is 25° C. to 100° C., and the time of the iron and aluminum removal treatment is 0.5 h to 8 h.

3. The wet treatment process of laterite nickel ore according to claim 1, characterized in that: In step S3, the first oxidant is selected from any one or more of a mixed gas of oxygen and sulfur dioxide, oxygen, ozone, persulfate, hydrogen peroxide, nitrite, and perchlorate, and / or the amount of the first oxidant added is 1.0 to 10.0 times the chemical reaction stoichiometric ratio of divalent iron in the washed slurry.

4. The wet treatment process of laterite nickel ore according to any one of claims 1 to 3, characterized in that: In step S3, the first neutralizing agent is selected from any one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, magnesium carbonate, magnesium bicarbonate, ammonium carbonate, ammonium bicarbonate, calcium oxide, magnesium oxide, sodium hydroxide, potassium hydroxide, ammonia water, calcium hydroxide, magnesium hydroxide, calcium carbonate, calcium bicarbonate, limestone, magnesia powder, magnesite, dolomite and marble.

5. The wet treatment process of laterite nickel ore according to any one of claims 1 to 3, characterized in that: In the step S4, the temperature of the nickel-cobalt precipitation treatment is 25° C. to 100° C., the time of the nickel-cobalt precipitation treatment is 0.5 h to 8 h; and / or the endpoint pH value of the nickel-cobalt precipitation treatment is 7.0 to 9.

0.

6. The wet treatment process of laterite nickel ore according to any one of claims 1 to 3, characterized in that: In the step S4, the process of the nickel-cobalt precipitation treatment includes: directly adding a precipitant into the iron-aluminum-removed solution to perform the nickel-cobalt precipitation treatment; Alternatively, a magnesium-containing solution is first reacted with a precipitant to generate active magnesium hydroxide, and then the active magnesium hydroxide is added to the iron- and aluminum-removed solution to perform the nickel-cobalt precipitation treatment; And / or the precipitant is selected from any one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, magnesium carbonate, magnesium bicarbonate, ammonium carbonate, ammonium bicarbonate, calcium oxide, magnesium oxide, sodium hydroxide, potassium hydroxide, ammonia water, calcium hydroxide, magnesium hydroxide, calcium carbonate and calcium bicarbonate.

7. The wet treatment process of laterite nickel ore according to any one of claims 1 to 3, characterized in that: In the step S1, the temperature of the acid leaching treatment is 90°C to 280°C, the time of the acid leaching treatment is 0.5h to 8h; and / or the endpoint acidity of the acid leaching treatment is 0.1g / L to 50g / L; and / or the pressure of the acid leaching treatment is 1MPa to 4MPa.

8. The wet treatment process of laterite nickel ore according to any one of claims 1 to 3, characterized in that: In the step S1, the inorganic acid is selected from any one or more of sulfuric acid, hydrochloric acid and nitric acid.

9. The wet treatment process of laterite nickel ore according to any one of claims 1 to 3, characterized in that: In step S2, the liquid-solid separation method is thickener separation or filter press separation; and / or the countercurrent washing method is any one of multi-stage thickener series countercurrent washing, filter press on-machine countercurrent washing and slurry countercurrent washing.

10. The wet treatment process of laterite nickel ore according to any one of claims 1 to 3, characterized in that: In step S6, the post-washing treatment process includes an acidic solution washing treatment, an alkaline solution washing treatment and a nickel-cobalt-containing solution washing treatment performed in sequence.

11. The wet treatment process of laterite nickel ore according to claim 10, characterized in that: In the step S6, the amount of the acidic solution used for the acidic solution washing treatment is 0.01% to 100% of the solid amount of the nickel cobalt hydroxide product; and / or the mass concentration of the acidic solution is 0.01 to 5wt%, and the acidic solution is selected from any one or more of sulfuric acid solution, hydrochloric acid solution, nitric acid solution, carbonic acid solution and organic acid solution; and / or the temperature of the acidic solution washing treatment is 25°C to 100°C, and the time of the acidic solution washing treatment is 0.5h to 8h.

12. The wet treatment process of laterite nickel ore according to claim 10, characterized in that: In the step S6, the amount of the alkaline solution used for the alkaline solution washing treatment is 0.01% to 100% of the solid amount of the nickel cobalt hydroxide product; and / or the mass concentration of the alkaline solution is 0.1 to 40wt%, and the alkaline solution is selected from one or more of sodium hydroxide solution, potassium hydroxide solution, ammonia water and carbonate solution; and / or the temperature of the alkaline solution washing treatment is 25°C to 100°C, and the time of the alkaline solution washing treatment is 0.5h to 8h.

13. The wet treatment process of laterite nickel ore according to claim 10, characterized in that: In the step S6, the mass of the nickel-cobalt solution used for the washing treatment of the nickel-cobalt solution is 0.01% to 100% of the solid mass of the nickel-cobalt hydroxide product; and / or the mass concentration of nickel and cobalt in the nickel-cobalt solution is 0.1 g / L to 100 g / L, and the nickel-cobalt solution is selected from any one or more of a leaching solution, a solution before iron and aluminum removal, a solution after iron and aluminum removal, and a self-prepared nickel-cobalt solution; and / or the temperature of the washing treatment of the nickel-cobalt solution is 25° C. to 100° C., and the washing treatment time of the nickel-cobalt solution is 0.5 h to 8 h.

14. The wet treatment process of laterite nickel ore according to any one of claims 1 to 3, characterized in that: The wet treatment process also includes: returning a portion of the overflow to the countercurrent washing step; The remaining overflow is neutralized with the leached residue to obtain tailings slurry; The temperature of the neutralization treatment is 25° C. to 100° C., and / or the time of the neutralization treatment is 0.5 h to 8 h; and / or the endpoint pH value of the neutralization treatment is 7.0 to 9.

0.

15. The wet treatment process of laterite nickel ore according to claim 14, characterized in that: During the neutralization treatment, a second oxidant and a second neutralizer are added, wherein the second oxidant is selected from any one or more of a mixture of oxygen and sulfur dioxide, oxygen, ozone, persulfate, hydrogen peroxide, nitrite, and perchlorate; and / or the second neutralizer is selected from any one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, magnesium carbonate, magnesium bicarbonate, ammonium carbonate, ammonium bicarbonate, calcium oxide, magnesium oxide, sodium hydroxide, potassium hydroxide, ammonia water, calcium hydroxide, magnesium hydroxide, calcium carbonate, and calcium bicarbonate.

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