Improved processing methods for laterite nickel ore

Abstract

This invention provides an improved processing method for laterite nickel ore. The improved method includes: Step S1, acid leaching followed by filtration and washing of the laterite nickel ore to obtain a post-leaching solution and a first leaching residue; Step S2, where Step S2 is selected from any one of Steps S2-1, S2-2, and S2-3; Step S3, using a precipitant to perform a first-stage precipitation of nickel and cobalt in the solution after aluminum and scandium removal or iron and aluminum removal, followed by thick filtration to obtain a first-stage precipitated nickel and cobalt solution and nickel and cobalt hydroxide product; Step S4, using a nickel and cobalt neutralizing agent and an oxidizing agent to perform a second-stage precipitation of nickel and cobalt in the first-stage precipitated nickel and cobalt solution to obtain magnesium manganese sulfate solution and nickel-cobalt-manganese slurry. Traditional processes utilize compressed air to oxidize ferrous iron, resulting in energy waste. This application uses manganese-containing substances as an oxidizing agent to oxidize ferrous iron to ferric iron, which not only solves the problem of slow oxidation rate of ferrous iron at low pH and waste of compressed air, but also improves the scandium recovery rate.

Description

Technical Field

[0001] This invention relates to the field of laterite nickel ore technology, and more specifically, to an improved processing method for laterite nickel ore. Background Technology

[0002] Currently, laterite nickel ore has become a major raw material in the EV battery industry chain. Among them, high-pressure leaching is the mainstream process for producing nickel-cobalt intermediate products. The main process is as follows: high-pressure leaching – pre-neutralization – two-stage iron and aluminum removal – two-stage nickel and cobalt precipitation – tailings neutralization. This process is a patented technology of China ENFI and is widely used by companies such as Ruimu, Huayou, and Liqin.

[0003] However, the biggest problem with this process is:

[0004] (1) In the iron and aluminum removal stage, compressed air and oxygen are introduced to oxidize ferrous iron. However, when the pH is low, the oxidation rate of ferrous iron is poor and the efficiency is low. The utilization rate of compressed air is low (<3%), which wastes a lot of electrical energy.

[0005] (2) Iron cannot be recovered and the slag rate is high. One ton of laterite nickel ore basically produces about 1.2 tons of slag, which cannot be recovered. If a tailings dam is used, it will pose a huge threat to environmental safety.

[0006] (3) After leaching, iron exists in a mixed form of ferrous and ferric iron. The ferrous iron oxidation precipitation has a high pH, ​​and it can generally be completely removed in the second stage of iron and aluminum removal (the final pH is around 4.8). This causes iron, aluminum and scandium to precipitate at the same time, and the mixture of iron, aluminum and scandium makes aluminum and scandium unrecoverable. Summary of the Invention

[0007] The main objective of this invention is to provide an improved processing method for laterite nickel ore, in order to solve the problem that the existing process for preparing nickel-cobalt hydroxide involves the extensive use of compressed air and oxygen for two-stage iron and aluminum removal, resulting in high costs.

[0008] To achieve the above objectives, according to one aspect of the present invention, an improved processing method for laterite nickel ore is provided, wherein the laterite nickel ore is a mixture of limonite-type laterite nickel ore and residual ore-type laterite nickel ore in any proportion. The improved processing method includes: step S1, acid leaching followed by filtration and washing of the laterite nickel ore to obtain a leaching solution and a first leaching residue; step S2, wherein step S2 is selected from any one of steps S2-1, S2-2, and S2-3; step S2-1: oxidizing the leaching solution with a manganese-containing substance to remove iron, obtaining an oxidized iron-removed slurry. The iron-removing slurry is neutralized and iron-removed sequentially using an iron-removing neutralizing agent, followed by liquid-solid separation to obtain iron-removed slag. The iron-removed slag is then treated with aluminum-washing alkaline solution to obtain a liquid phase and high-iron slag products. An aluminum-scandium precipitation neutralizing agent is used to treat the liquid phase to precipitate aluminum and scandium, resulting in scandium-rich aluminum slag and a post-aluminum-scandium leaching solution. Step S2-2: The post-leaching solution is oxidized and iron-removed using a manganese-containing substance to obtain an iron-removing slurry. The iron-removing slurry is pre-neutralized and liquid-solid separated sequentially using a pre-neutralizing agent to obtain neutralized slag. The neutralized slag is then washed to obtain a liquid phase and a second leaching slag. A first-stage iron and aluminum removal neutralizing agent is used to remove iron and aluminum from the liquid phase, resulting in open-circuit iron and aluminum slag and the liquid after the first-stage iron and aluminum removal. A second-stage iron and aluminum removal neutralizing agent is then used to remove iron and aluminum from the liquid after the first-stage iron and aluminum removal, resulting in second-stage iron and aluminum slag and the liquid after the first-stage iron and aluminum removal. The second-stage iron and aluminum slag is returned to the iron oxidation step. Step S2-3: The leaching liquid is circulated for leaching to obtain circulating leaching slurry. The circulating leaching slurry is pre-neutralized and then subjected to liquid-solid separation using a pre-neutralizing agent to obtain neutralized slag. The neutralized slag is then washed to obtain the liquid phase and the second leaching slag. A first-stage iron and aluminum removal neutralizing agent is then used. The liquid phase undergoes a first-stage iron and aluminum removal process to obtain open-circuit iron and aluminum slag and a first-stage iron and aluminum removal liquid. A manganese-containing substance is then used to perform a second-stage iron and aluminum removal process on the liquid after the first-stage iron and aluminum removal, resulting in a second-stage iron and aluminum slag and a second-stage iron and aluminum removal liquid. The second-stage iron and aluminum slag is returned to the circulating leaching step. In step S3, a precipitant is used to perform a first-stage nickel and cobalt precipitation and thickening filtration on the liquid after aluminum and scandium removal or the liquid after iron and aluminum removal, resulting in a first-stage nickel and cobalt precipitated liquid and nickel and cobalt hydroxide product. In step S4, a nickel and cobalt neutralizing agent and an oxidizing agent are used to perform a second-stage nickel and cobalt precipitation on the liquid after the first-stage nickel and cobalt precipitated liquid, resulting in magnesium manganese sulfate solution and nickel-cobalt-manganese slurry.

[0009] Furthermore, the aforementioned manganese-containing substances are selected from any one or more of nickel-cobalt-manganese paste, manganese dioxide, potassium permanganate, sodium permanganate, pyrolusite, manganese trioxide, and manganese tetroxide.

[0010] Furthermore, in step S2-1 above, the molar ratio of manganese in the manganese-containing substance to ferrous iron in the leaching solution is 0.1 to 10:1; and / or, the oxidation temperature for iron removal is 25°C to 100°C, and the oxidation time for iron removal is 0.1 h to 5 h.

[0011] Further, in step S2-1 above, the endpoint pH for iron neutralization is 2.8–3.5, the temperature for iron neutralization is 25℃–100℃, and the time for iron neutralization is 0.5h–8h; the iron 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, calcium hydroxide, magnesium hydroxide, calcium carbonate, calcium bicarbonate, limestone, magnesia powder, magnesite, dolomite, and marble.

[0012] Further, in step S2-1 above, the mass concentration of the aluminum washing alkaline solution is 0.1wt% to 40wt%, the amount of aluminum washing alkaline solution used is 0.8 to 8 times the stoichiometric ratio of aluminum in the iron removal slag; and / or the temperature of the aluminum washing treatment is 25℃ to 100℃, the time of the aluminum washing treatment is 0.5h to 8h; and / or, the magnesium manganese sulfate solution is returned to step S2-1 as the aluminum washing alkaline solution.

[0013] Further, in step S2-1 above, the final pH of the scandium precipitate treatment is 4.5–5.2, the temperature of the scandium precipitate treatment is 25℃–100℃, and the treatment time is 0.5h–8h; and / or, the scandium precipitate 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, calcium hydroxide, magnesium hydroxide, calcium carbonate, calcium bicarbonate, limestone, magnesia powder, magnesite, dolomite, and marble.

[0014] Furthermore, step S2-1 above also includes: drying and roasting the iron slag obtained from aluminum washing treatment in sequence to obtain high iron slag product; wherein, the roasting temperature is 500℃~1200℃, the roasting time is 1min~5h, and the iron content in the high iron slag product is 55%~65%.

[0015] Furthermore, in step S2-2 above, the temperature for iron removal through oxidation is 25℃~100℃, and the time for iron removal through oxidation is 0.1h~5h.

[0016] Further, in step S2-2 above, the pre-neutralizing agent, the first-stage iron-aluminum removal neutralizing agent, and the second-stage iron-aluminum removal neutralizing agent are each independently 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, calcium hydroxide, magnesium hydroxide, calcium carbonate, calcium bicarbonate, limestone, magnesite powder, magnesite, dolomite, and marble; and / or The pre-neutralization endpoint pH is 1–2, the pre-neutralization temperature is 25℃–100℃, and the pre-neutralization time is 0.5h–8h; and / or, the first stage of iron and aluminum removal endpoint pH is 3–4, the first stage of iron and aluminum removal temperature is 25℃–100℃, and the first stage of iron and aluminum removal time is 0.5h–8h; and / or, the second stage of iron and aluminum removal endpoint pH is 4–5, the second stage of iron and aluminum removal temperature is 25℃–100℃, and the second stage of iron and aluminum removal time is 0.5h–8h.

[0017] Furthermore, in steps S2-3 above, the molar ratio of manganese in the manganese-containing substance to ferrous iron in the liquid after iron and aluminum removal is 0.1 to 10:1.

[0018] Further, in steps S2-3 above, the pre-neutralizing agent and the first-stage iron and aluminum removal neutralizing agent are each independently 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, calcium hydroxide, magnesium hydroxide, calcium carbonate, calcium bicarbonate, limestone, magnesia powder, magnesite, dolomite, and marble; and / or, the endpoint pH of pre-neutralization is 1-2, the pre-neutralization temperature is 25℃-100℃, and the pre-neutralization time is 0.5h-8h; and / or, the endpoint pH of the first-stage iron and aluminum removal is 3-4, the first-stage iron and aluminum removal temperature is 25℃-100℃, and the first-stage iron and aluminum removal time is 0.5h-8h; and / or, the endpoint pH of the second-stage iron and aluminum removal is 4-5, the second-stage iron and aluminum removal temperature is 25℃-100℃, and the second-stage iron and aluminum removal time is 0.1h-5h.

[0019] Furthermore, in step S3 above, the final pH of the first stage of nickel-cobalt precipitation is 7.0 to 8.0, the temperature of the first stage of nickel-cobalt precipitation is 25℃ to 100℃, and the precipitation time is 0.5h to 8h; the precipitant is selected from any one or more of magnesium oxide, sodium hydroxide, and calcium hydroxide.

[0020] Further, in step S4 above, the endpoint pH of the two-stage nickel-cobalt precipitation is 8.0–9.0, the temperature of the two-stage nickel-cobalt precipitation is 25℃–100℃, and the time of the two-stage nickel-cobalt precipitation is 0.5h–8h; and / or, the nickel-cobalt 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, calcium hydroxide, magnesium hydroxide, calcium carbonate, and calcium bicarbonate; and / or, the oxidizing agent is selected from any one or more of a mixture of sulfur dioxide and oxygen, oxygen, compressed air, oxygen-enriched air, hydrogen peroxide, sodium persulfate, potassium persulfate, and potassium permanganate.

[0021] Furthermore, in step S1 above, the acid leaching temperature is 80℃~280℃, the acid leaching time is 0.1~10h, and the acid-to-ore ratio is 200~400kg / t ore.

[0022] Furthermore, the above-mentioned improved treatment method also includes: leaching scandium-rich aluminum slag with an aluminum leaching alkaline solution to obtain scandium-rich slag product and a post-leaching solution; wherein the mass concentration of the aluminum leaching alkaline solution is 0.1wt% to 40wt%, and the amount of aluminum leaching alkaline solution used is 0.8 to 8 times the stoichiometric ratio of aluminum in the scandium-rich aluminum slag; and / or, the temperature of the aluminum leaching treatment is 25℃ to 100℃, and the time of the aluminum leaching treatment is 0.5h to 8h; and / or, the post-leaching solution is recycled and used as an aluminum leaching alkaline solution.

[0023] The traditional process using compressed air to oxidize ferrous iron (Fe2+) using the technical solution of this application is inefficient, with a utilization rate of less than 3%, resulting in energy waste. This application uses manganese-containing substances as an oxidant to oxidize ferrous iron (Fe2+) to ferric iron (Fe3+), which not only solves the problem of slow oxidation rate and wasted compressed air at low pH, improving oxidation efficiency and manganese utilization, but also allows ferric iron to precipitate at lower pH, thereby reducing aluminum and scandium precipitation and achieving effective separation of iron and aluminum / scandium, thus improving scandium recovery rate. Furthermore, there are four specific methods for oxidizing ferrous iron to ferric iron, which can be found in [reference needed]. Figures 1 to 4 The difference in process lies in step S2. It is evident that the main effects of the improved treatment method for laterite nickel ore are: significantly improved efficiency of ferrous iron oxidation and manganese utilization, reduced use of compressed air or oxygen, reduced electricity consumption, and lower production costs; effective iron recovery reduces slag rate and tailings pond usage, greatly reducing environmental safety hazards and pollution; effective separation of iron, aluminum, and scandium is achieved, improving scandium and aluminum recovery rates, while also enhancing nickel and cobalt recovery rates and product quality; this method provides four process routes, enhancing the adaptability and flexibility of the process. Attached Figure Description

[0024] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0025] Figure 1 A process flow diagram of an improved processing method for laterite nickel ore according to Embodiment 1 of the present invention is shown;

[0026] Figure 2 A process flow diagram of an improved processing method for laterite nickel ore according to Embodiment 2 of the present invention is shown;

[0027] Figure 3 A process flow diagram of an improved processing method for laterite nickel ore according to Embodiment 3 of the present invention is shown;

[0028] Figure 4 A process flow diagram of an improved processing method for laterite nickel ore according to Embodiment 4 of the present invention is shown. Detailed Implementation

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] As described in the background section, the existing process for preparing nickel-cobalt hydroxide suffers from high costs due to the extensive use of compressed air and oxygen for two-stage iron and aluminum removal. To address this issue, the present invention provides an improved processing method for laterite nickel ore.

[0031] In one typical embodiment of this application, an improved processing method for laterite nickel ore is provided. The laterite nickel ore is a mixture of limonite-type laterite nickel ore and residual laterite nickel ore in any proportion, as described above. Figures 1 to 4The improved treatment method includes: Step S1, acid leaching and subsequent filtration and washing of laterite nickel ore to obtain leaching solution and first leaching residue; Step S2, which is selected from any one of Step S2-1, Step S2-2, and Step S2-3; Step S2-1: Oxidizing the leaching solution with manganese-containing substances to remove iron, obtaining an oxidized iron-removed slurry; neutralizing and removing iron and separating liquid and solid in the oxidized iron-removed slurry with an iron-removing neutralizing agent to obtain iron-removed residue; and washing the iron-removed residue with an aluminum-washing alkaline solution. The process involves obtaining a liquid phase and high-iron slag products; treating the liquid phase with a scandium-precipitating neutralizing agent to obtain scandium-rich aluminum slag and scandium-removed leaching solution; step S2-2: using manganese-containing substances to oxidize and remove iron from the leaching solution to obtain an oxidized iron-removed slurry; using a pre-neutralizing agent to pre-neutralize and then separate the oxidized iron-removed slurry to obtain a neutralized slag, which is then washed to obtain a liquid phase and a second leaching slag; using a first-stage iron-aluminum removal neutralizing agent to perform a first-stage iron-aluminum removal process on the liquid phase to obtain an open-circuit iron-aluminum slag and a first-stage iron-aluminum-removed leaching solution. A two-stage iron-aluminum removal neutralizing agent is used to perform a second-stage iron-aluminum removal process on the liquid after the first-stage iron-aluminum removal, resulting in a second-stage iron-aluminum slag and a liquid after iron-aluminum removal. The second-stage iron-aluminum slag is returned to the iron oxidation step. Step S2-3: The leaching liquid is leached in a circulating manner to obtain a circulating leaching slurry. The circulating leaching slurry is pre-neutralized and then separated into liquid and solid phases using a pre-neutralizing agent to obtain a neutralized slag. The neutralized slag is washed to obtain a liquid phase and a second leaching slag. The liquid phase is then subjected to a first-stage iron-aluminum removal process using a first-stage iron-aluminum removal neutralizing agent to obtain an open-circuit iron-aluminum slag. The slag and the liquid after the first stage of iron and aluminum removal are subjected to a second stage of iron and aluminum removal using a manganese-containing substance, resulting in a second stage of iron-aluminum slag and iron-aluminum removal liquid. The second stage of iron-aluminum slag is returned to the circulating leaching step. In step S3, a precipitant is used to precipitate nickel and cobalt in the liquid after aluminum and scandium removal or the liquid after iron and aluminum removal, followed by thick filtration, to obtain a first stage of nickel-cobalt precipitated liquid and nickel-cobalt hydroxide product. In step S4, a nickel-cobalt neutralizing agent and an oxidizing agent are used to precipitate nickel and cobalt in the liquid after the first stage of nickel-cobalt precipitated liquid, resulting in a second stage of nickel-cobalt precipitation, resulting in magnesium-manganese sulfate solution and nickel-cobalt-manganese slurry.

[0032] Traditional processes utilize compressed air to oxidize ferrous iron (Fe2+), resulting in low efficiency (less than 3% utilization) and energy waste. This application uses manganese-containing substances as an oxidant to oxidize ferrous iron (Fe2+) to ferric iron (Fe3+). This not only solves the problems of slow oxidation rate and compressed air waste at low pH, improving oxidation efficiency and manganese utilization, but also allows ferric iron to precipitate at lower pH, reducing aluminum and scandium precipitation and achieving effective separation of iron and aluminum / scandium, thus improving scandium recovery. Furthermore, there are four specific methods for oxidizing ferrous iron to ferric iron, which can be found in [reference needed]. Figures 1 to 4The difference in process lies in step S2. It is evident that the main effects of the improved treatment method for laterite nickel ore are: significantly improved efficiency of ferrous iron oxidation and manganese utilization, reduced use of compressed air or oxygen, reduced electricity consumption, and lower production costs; effective iron recovery reduces slag rate and tailings pond usage, greatly reducing environmental safety hazards and pollution; effective separation of iron, aluminum, and scandium is achieved, improving scandium and aluminum recovery rates, while also enhancing nickel and cobalt recovery rates and product quality; this method provides four process routes, enhancing the adaptability and flexibility of the process.

[0033] In one embodiment of this application, the manganese-containing substance is selected from any one or more of nickel-cobalt-manganese paste, manganese dioxide, potassium permanganate, sodium permanganate, pyrolusite, manganese trioxide, and manganese tetroxide.

[0034] On the one hand, manganese in the aforementioned high-priced manganese-containing materials has strong oxidizing properties, which can oxidize ferrous iron to ferric iron, accelerating the oxidation reaction and improving oxidation efficiency. On the other hand, using manganese-containing materials from different sources and with different properties as oxidants can provide greater flexibility and adaptability to the process. Furthermore, the oxidation process of manganese-containing materials generally produces less greenhouse gas emissions and energy consumption, which helps to reduce the overall environmental impact of the process, making it greener and more sustainable. In addition, compared with nickel-cobalt-manganese slurry as a manganese-containing material, manganese dioxide, potassium permanganate, sodium permanganate, pyrolusite, manganese trioxide, and manganese tetroxide can reduce the risk of introducing impurities from manganese-containing materials. However, compared with manganese-containing materials, manganese dioxide, potassium permanganate, sodium permanganate, pyrolusite, manganese trioxide, and manganese tetroxide are more expensive. This application preferably uses nickel-cobalt-manganese slurry as a manganese-containing material, which can not only reduce costs but also reduce the storage difficulty and post-processing energy consumption of nickel-cobalt-manganese slurry.

[0035] In one embodiment of this application, in step S2-1 above, the molar ratio of manganese in the manganese-containing substance to ferrous iron in the leaching solution is 0.1 to 10:1; and / or, the oxidation temperature for iron removal is 25°C to 100°C, and the oxidation time for iron removal is 0.1 h to 5 h.

[0036] Controlling the molar ratio of manganese in manganese-containing substances to ferrous iron in the leaching solution helps to control the oxidation potential of ferrous iron to ferric iron to be no higher than 400mV. This not only helps to make the oxidation reaction of ferrous iron to ferric iron more complete, but also minimizes the occurrence of side reactions.

[0037] As temperature increases, the oxidation reaction rate accelerates, helping to shorten the time required to reach the desired oxidation level and improve production efficiency. However, excessively high temperatures may lead to side reactions and additional energy consumption. Controlling the upper limit of the temperature to 100℃ helps to keep the reaction under control and efficient conditions. The preferred oxidation time promotes the full progress of the reaction while reducing unnecessary waiting time, thus improving overall productivity. Comprehensive control of the above temperature and time can reduce energy consumption, heat loss, and equipment wear, which is beneficial for energy conservation, emission reduction, and lower production costs. Furthermore, the preferred molar ratio of manganese in the manganese-containing material to ferrous iron in the leaching solution is 1–5:1; the oxidation temperature for iron removal is 40℃–80℃; and the oxidation time for iron removal is 1–2 hours.

[0038] In one embodiment of this application, in step S2-1 above, the endpoint pH of iron neutralization is 2.8 to 3.5, the temperature of iron neutralization is 25°C to 100°C, and the time of iron neutralization is 0.5h to 8h; the iron 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, calcium hydroxide, magnesium hydroxide, calcium carbonate, calcium bicarbonate, limestone, magnesia powder, magnesite, dolomite, and marble.

[0039] Because manganese-containing substances are used to oxidize and remove iron from the leaching solution, ferrous ions are fully oxidized to ferric ions. This allows neutralization and iron removal to proceed within the lower pH range, enabling the ferric ions to effectively precipitate and form ferric hydroxide, while other metals (such as aluminum and scandium) remain dissolved at this pH, thus achieving preliminary metal separation. A neutralization temperature of 25℃ to 100℃ accelerates the precipitation rate of ferric ions, shortens the reaction time, and improves production efficiency. An optimal neutralization time ensures sufficient precipitation of ferric ions while avoiding excessive energy and time waste, balancing efficiency and effectiveness. Different neutralizing agents have different chemical properties and costs. Selecting a neutralizing agent with good compatibility with the slurry system and lower cost, based on the actual process conditions, can optimize the precipitation effect while controlling production costs. Furthermore, a preferred neutralization temperature is 30℃ to 80℃, and the preferred neutralization time is 1 hour to 5 hours.

[0040] In one embodiment of this application, in step S2-1 above, the mass concentration of the aluminum washing alkaline solution is 0.1wt% to 40wt%, the amount of aluminum washing alkaline solution used is 0.8 to 8 times the stoichiometric ratio of aluminum in the iron removal slag; and / or the temperature of the aluminum washing treatment is 25℃ to 100℃, the time of the aluminum washing treatment is 0.5h to 8h; and / or, the magnesium manganese sulfate solution is returned to step S2-1 as the aluminum washing alkaline solution.

[0041] Higher alkali concentrations accelerate the dissolution process but may increase chemical costs and energy consumption; while lower concentrations are cheaper but may require longer processing times. Selecting the above-mentioned alkali concentration for aluminum washing effectively dissolves metals such as aluminum and scandium while reducing the dissolution of other metals (such as iron, nickel, and cobalt), achieving selective aluminum washing and balancing cost and processing efficiency. Excessive alkali may introduce unwanted impurities, affecting the quality and purity of subsequent metal recovery. Controlling the amount of alkali used for aluminum washing within the above-mentioned range ensures complete dissolution of metals such as aluminum and scandium, improving recovery rates, while also reducing the risk of impurities introduced by excessive alkali. Temperature control is crucial; excessively high temperatures or prolonged times may promote the dissolution of non-target metals or cause the metals in the solution to form complex compounds, affecting subsequent separation and recovery. Selecting the above-mentioned temperature and time ranges facilitates the effective dissolution of aluminum and scandium while reducing the risk of unnecessary side reactions. Returning the magnesium manganese sulfate solution to step S2-1 as the alkali for aluminum washing helps reduce costs and achieves waste reuse. Furthermore, the preferred aluminum washing alkaline solution has a mass concentration of 3wt% to 20wt%, and the amount of aluminum washing alkaline solution used is 1 to 5 times the stoichiometric ratio of aluminum in the iron removal slag; and / or the aluminum washing treatment temperature is 30℃ to 90℃, and the aluminum washing treatment time is 1h to 5h.

[0042] In one embodiment of this application, in step S2-1 above, the final pH of the scandium precipitate treatment is 4.5 to 5.2, the temperature of the scandium precipitate treatment is 25°C to 100°C, and the treatment time is 0.5h to 8h; and / or, the scandium precipitate 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, calcium hydroxide, magnesium hydroxide, calcium carbonate, calcium bicarbonate, limestone, magnesia powder, magnesite, dolomite, and marble.

[0043] Excessively high pH can lead to co-precipitation of metals such as nickel and cobalt, while excessively low pH may prevent complete precipitation of aluminum and scandium. Selecting a pH within the range specified above minimizes the co-precipitation of non-target metals, thereby reducing the complexity and cost of subsequent processing. Temperature control helps suppress undesirable side reactions, such as the formation of complex compounds between metals, ensuring the purity and selectivity of the precipitated aluminum and scandium. Controlling the temperature and time of the aluminum and scandium precipitation process within the above range helps to maximize the balance between production speed and precipitation efficiency. Different aluminum and scandium neutralizing agents have different levels of alkalinity and reactivity characteristics. Selecting a suitable neutralizing agent from the above categories, based on actual operational needs, can optimize the aluminum and scandium precipitation effect and improve metal recovery.

[0044] In one embodiment of this application, step S2-1 further includes: drying and roasting the iron slag obtained from aluminum washing treatment in sequence to obtain a high-iron slag product; wherein the roasting temperature is 500℃~1200℃, the roasting time is 1min~5h, and the iron content in the high-iron slag product is 55%~65%.

[0045] Existing processes generate large amounts of iron slag that cannot be effectively recycled, resulting in a high slag ratio and posing a threat to environmental safety. This method achieves efficient iron recovery by controlling specific conditions and converts the iron slag into high-iron products through roasting, thereby reducing the slag ratio and alleviating environmental pressure.

[0046] In one embodiment of this application, in step S2-2 above, the temperature for iron removal by oxidation is 25°C to 100°C, and the time for iron removal by oxidation is 0.1h to 5h.

[0047] Oxidation and iron removal within the above temperature and time range helps to find the optimal balance between oxidation effect and energy consumption. Furthermore, the preferred oxidation and iron removal temperature is 40℃~90℃, and the oxidation and iron removal time is 1h~4h.

[0048] In one embodiment of this application, in step S2-2 above, the pre-neutralizing agent, the first-stage iron-aluminum removal neutralizing agent, and the second-stage iron-aluminum removal neutralizing agent are each independently 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; And / or, the endpoint pH of pre-neutralization is 1–2, the pre-neutralization temperature is 25℃–100℃, and the pre-neutralization time is 0.5h–8h; and / or, the endpoint pH of the first stage of iron and aluminum removal is 3–4, the first stage of iron and aluminum removal temperature is 25℃–100℃, and the first stage of iron and aluminum removal time is 0.5h–8h; and / or, the endpoint pH of the second stage of iron and aluminum removal is 4–5, the second stage of iron and aluminum removal temperature is 25℃–100℃, and the second stage of iron and aluminum removal time is 0.5h–8h.

[0049] Different neutralizing agents may have varying effects on the precipitation behavior of metal ions in solution. Selecting an appropriate neutralizing agent can achieve selective precipitation of metals such as iron, aluminum, and scandium, helping to improve metal recovery rates and purity. The pre-neutralization process, by controlling the endpoint pH, can initiate the precipitation of some metal ions, laying the foundation for subsequent, more refined metal separation. The temperature and time of pre-neutralization ensure that all metal ions requiring precipitation react fully, avoiding metal residues that could affect subsequent processing. By precisely controlling the endpoint pH of the first-stage iron and aluminum removal, a large amount of iron can be removed while reducing the co-precipitation of aluminum and scandium, improving metal separation efficiency. Adjusting the endpoint temperature and time of the first-stage iron and aluminum removal can optimize the composition of the precipitate, reduce unnecessary byproducts, and improve the economic benefits of metal recovery. The second-stage iron and aluminum removal, as a further metal separation step, allows for more precise metal separation by controlling the endpoint pH, temperature, and time, especially for trace amounts of iron that are difficult to remove completely, minimizing aluminum and scandium losses and maximizing their recovery rate.

[0050] In one embodiment of this application, in steps S2-3 above, the molar ratio of manganese in the manganese-containing substance to divalent iron in the liquid after iron and aluminum removal is 0.1 to 10:1.

[0051] Manganese in manganese-containing substances acts as an oxidant, effectively oxidizing ferrous iron (Fe2+) to ferric iron (Fe3+). By controlling the molar ratio of manganese to ferrous iron within the above range, this oxidation process can be optimized, avoiding excessive or insufficient manganese consumption, ensuring the completeness and efficiency of the oxidation reaction, thereby improving the precipitation and removal efficiency of iron. Furthermore, the preferred molar ratio of manganese in the manganese-containing substance to ferrous iron in the liquid after the first stage of iron and aluminum removal is 1–6:1.

[0052] In one embodiment of this application, in steps S2-3 above, the pre-neutralizing agent and the first-stage iron and aluminum removal neutralizing agent are each independently 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, calcium hydroxide, magnesium hydroxide, calcium carbonate, calcium bicarbonate, limestone, magnesite powder, magnesite, dolomite, and marble; and / or, the endpoint pH of the pre-neutralization is 1-2, the pre-neutralization temperature is 25℃-100℃, and the pre-neutralization time is 0.5h-8h; and / or, the endpoint pH of the first-stage iron and aluminum removal is 3-4, the first-stage iron and aluminum removal temperature is 25℃-100℃, and the first-stage iron and aluminum removal time is 0.5h-8h; and / or, the endpoint pH of the second-stage iron and aluminum removal is 4-5, the second-stage iron and aluminum removal temperature is 25℃-100℃, and the second-stage iron and aluminum removal time is 0.1h-5h.

[0053] Different neutralizing agents, due to their varying chemical properties, can influence the precipitation selectivity of metal ions in solution. Selecting an appropriate neutralizing agent can achieve selective precipitation of metals, helping to improve metal recovery and purity. The endpoint pH of pre-neutralization directly affects the initial distribution of metal ions in the solution. The aforementioned endpoint pH values ​​help to separate some easily precipitated metals in advance, improving the targeting and efficiency of subsequent processing. Controlling the endpoint pH of the first and second stages of iron and aluminum removal is crucial for the effective separation of iron from aluminum and scandium. Lower pH values ​​(such as after pre-neutralization) promote the preferential precipitation of iron, while as the pH gradually increases, metals such as aluminum and scandium begin to precipitate. By controlling the pH value in stages, orderly metal separation can be achieved, reducing the loss of aluminum and scandium. Selecting the above-mentioned temperatures and times helps to balance the precipitation rates and side reactions of the pre-neutralizing agent, the first stage of iron and aluminum removal, and the second stage of iron and aluminum removal.

[0054] In one embodiment of this application, in step S3 above, the final pH of the first stage of nickel-cobalt precipitation is 7.0 to 8.0, the temperature of the first stage of nickel-cobalt precipitation is 25°C to 100°C, and the precipitation time is 0.5h to 8h; the precipitant is selected from any one or more of magnesium oxide, sodium hydroxide, and calcium hydroxide.

[0055] Within the final pH range of the above-mentioned nickel-cobalt precipitation stage, the precipitation selectivity of nickel-cobalt ions is high, effectively separating nickel-cobalt compounds from the solution while avoiding premature precipitation of other metals (such as manganese), thereby improving the purity and recovery rate of the nickel-cobalt product. A moderate increase in the temperature for the first-stage precipitation of nickel-cobalt can accelerate ion movement and improve precipitation efficiency; however, excessively high temperatures may trigger unnecessary side reactions, such as accelerating hydrolysis or promoting the oxidation of certain metals. Choosing the above-mentioned temperature ensures both the reaction rate and completeness while reducing energy consumption during heating. A shorter precipitation time may not be sufficient for complete precipitation of all nickel-cobalt ions, while an excessively long time may increase energy consumption and production costs. The above-mentioned precipitation time helps to balance the efficiency of complete nickel-cobalt ion precipitation and energy consumption.

[0056] In one embodiment of this application, in step S4 above, the endpoint pH of the two-stage nickel-cobalt precipitation is 8.0 to 9.0, the temperature of the two-stage nickel-cobalt precipitation is 25°C to 100°C, and the time of the two-stage nickel-cobalt precipitation is 0.5h to 8h; and / or, the nickel-cobalt 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, calcium hydroxide, magnesium hydroxide, calcium carbonate, and calcium bicarbonate; and / or, the oxidizing agent is selected from any one or more of a mixture of sulfur dioxide and oxygen, oxygen, compressed air, oxygen-enriched air, hydrogen peroxide, sodium persulfate, potassium persulfate, and potassium permanganate.

[0057] The endpoint pH of the two-stage nickel-cobalt precipitation enhances the selective precipitation of nickel-cobalt ions, which contributes to the formation of a purer nickel-cobalt product. Simultaneously, it inhibits the precipitation of other metals (such as manganese, aluminum, and scandium) under the same conditions (resulting in byproducts such as aluminum hydroxide and scandium hydroxide), thereby improving the recovery rate and purity of nickel-cobalt. The selection of temperature and time for the two-stage nickel-cobalt precipitation helps balance the efficiency and effectiveness of complete nickel-cobalt ion precipitation. Choosing the above-mentioned precipitants helps improve the precipitation efficiency and selectivity of nickel-cobalt and reduces the co-precipitation of other undesirable metal ions. During the two-stage nickel-cobalt precipitation process, the oxidant aims to oxidize certain low-valence metals in the solution, causing them to precipitate at a higher pH. The synergistic effect of the above-mentioned precipitants and oxidants results in better selective precipitation of nickel-cobalt ions in the two-stage nickel-cobalt precipitation process.

[0058] In one embodiment of this application, in step S1 above, the acid leaching temperature is 80℃~280℃, the acid leaching time is 0.1~10h, and the acid-to-ore ratio is 200~400kg / t ore.

[0059] A faster acid leaching reaction rate helps improve the leaching efficiency of metals such as nickel and cobalt in laterite nickel ore. The temperature and time of acid leaching can promote the faster and more complete dissolution of metal ions from the ore into the solution, thereby increasing the raw material concentration for subsequent metal recovery. A higher acid-to-ore ratio can increase the acid concentration in the solution, promoting the dissolution of metal ions, but it also increases acid consumption and the cost of treating acidic wastewater. By optimizing the acid-to-ore ratio, unnecessary acid usage can be reduced, thereby lowering energy consumption, including energy used in heating and stirring processes.

[0060] In one embodiment of this application, the improved processing method further includes: leaching scandium-rich aluminum slag with an aluminum leaching alkaline solution to obtain a scandium-rich slag product and an aluminum-leaching post-solution; wherein the mass concentration of the aluminum leaching alkaline solution is 0.1wt% to 40wt%, and the amount of aluminum leaching alkaline solution used is 0.8 to 8 times the stoichiometric ratio of aluminum in the scandium-rich aluminum slag; and / or, the temperature of the aluminum leaching treatment is 25℃ to 100℃, and the time of the aluminum leaching treatment is 0.5h to 8h; and / or, the aluminum-leaching post-solution is recycled and used as an aluminum leaching alkaline solution.

[0061] Maintaining the above-mentioned concentration of the aluminum leaching alkaline solution ensures efficient dissolution of aluminum in scandium-rich aluminum slag, thereby improving aluminum recovery. Using an amount of aluminum leaching alkaline solution within the above-mentioned stoichiometric ratio of aluminum in the scandium-rich aluminum slag ensures sufficient aluminum dissolution while avoiding excessive scandium dissolution, achieving effective aluminum-scandium separation. Suitable temperature and time can reduce side reactions, such as preventing the dissolution of other metal ions like scandium and iron, maintaining the purity of the leaching solution, and reducing the complexity of subsequent separation processes. Further, it is preferred that the concentration of the aluminum leaching alkaline solution is 1wt%–15wt%, the amount of aluminum leaching alkaline solution used is 1–5 times the stoichiometric ratio of aluminum in the scandium-rich aluminum slag; and / or, the leaching temperature is 30℃–90℃, and the leaching time is 1h–5h.

[0062] The raw material laterite nickel ore contains 0.8–1.5 wt% nickel, 0.01–0.3 wt% cobalt, 40–45 wt% iron, 0.5–5 wt% magnesium, 0.5–2 wt% manganese, 0.5–4 wt% aluminum, and 20–80 ppm scandium.

[0063] The concentration of various metal ions in the raw material laterite nickel ore affects the difficulty and cost of subsequent iron removal processes. Controlling the concentration of each metal ion within the above-mentioned range helps optimize subsequent precipitation conditions, reduces the interference of iron precipitation on nickel-cobalt recovery, and thus improves the recovery rate and purity of the target metal.

[0064] In a preferred embodiment of this application, the above preparation process results in a nickel content of 39-45 wt% and a cobalt content of 3-5 wt% in the nickel-cobalt hydroxide product, thereby improving its utilization value.

[0065] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0066] Example 1

[0067] Reference Figure 1 The process flow diagram for improving the processing of laterite nickel ore is as follows:

[0068] The raw material is limonite-type lateritic nickel ore with a nickel content of 1.2%, cobalt content of 0.12 wt%, iron content of 45%, magnesium content of 2%, manganese content of 0.8 wt%, aluminum content of 1.5 wt%, and scandium content of 40 ppm. It is subjected to high-pressure sulfuric acid leaching at an acid-to-ore ratio of 250 kg / t ore, a temperature of 255℃, and a leaching time of 1 hour. After leaching, the leaching solution is filtered and washed to obtain the leaching residue and the first leaching residue. After leaching, the liquid temperature was 90℃. A second-stage nickel-cobalt-manganese slurry (nickel-cobalt-manganese slurry) was introduced for oxidation and iron removal, resulting in an oxidized iron-removed slurry. The manganese-iron ratio (molar ratio of ferrous iron in the second-stage nickel-cobalt-manganese slurry to that in the leaching liquid) was 1:1. The treatment time was 1 hour, and the potential was 400 mV. Magnesium oxide was then used to neutralize and remove iron from the oxidized iron-removed slurry. The final pH was controlled at 3.3 for 3 hours, achieving an iron removal rate of 99.8%. After filtration, iron-removed slag was obtained. The filter cake was then treated with sodium hydroxide solution to remove aluminum at 90℃. The dosage coefficient of the sodium hydroxide solution (20 wt%) (the amount of sodium hydroxide solution was three times the stoichiometric ratio of aluminum in the iron-removed slag) was 3 for 3 hours. After washing away the aluminum, a liquid phase and a filter cake were obtained. The filter cake was dried and then roasted at 800℃ for 2 hours to obtain a high-iron slag product, hematite, with an iron content of 63%. Magnesium oxide was added to the liquid phase for scandium precipitation, with the final pH controlled at 4.8 for 3 hours, yielding scandium-rich aluminum slag and a post-scandium leaching solution. The scandium-rich aluminum slag was then leached with sodium hydroxide solution at 90℃, with a sodium hydroxide solution dosage coefficient (the amount of sodium hydroxide solution was four times the stoichiometric ratio of aluminum in the scandium-rich aluminum slag) of 4, for 3 hours, yielding scandium-rich slag product and a post-aluminum leaching solution. The post-aluminum leaching solution was used to produce aluminum hydroxide. The post-scandium leaching solution was then subjected to a first-stage nickel-cobalt precipitation with sodium hydroxide at 65℃ for 3 hours, with the final pH controlled at 8.0, yielding an MHP product and a post-nickel-cobalt precipitation solution. Magnesium oxide was then used to neutralize the post-nickel-cobalt precipitation solution, while compressed air was introduced for a second-stage nickel-cobalt precipitation at 65℃ for 3 hours, with the final pH controlled at 8.5. After precipitation, the solution is thickened to obtain magnesium manganese sulfate solution and nickel cobalt manganese slurry. The thickened underflow nickel cobalt manganese slurry is returned to the above-mentioned oxidation and iron removal step.

[0069] Example 2

[0070] Reference Figure 2 The process flow diagram for improving the processing of laterite nickel ore is as follows:

[0071] The raw material is limonite-type lateritic nickel ore with a nickel content of 1.2%, cobalt content of 0.12 wt%, iron content of 45%, magnesium content of 2%, manganese content of 0.8 wt%, aluminum content of 1.5 wt%, and scandium content of 40 ppm. The ore is subjected to high-pressure sulfuric acid leaching, during which a two-stage nickel-cobalt-manganese slurry (nickel-cobalt-manganese slurry) is introduced. The acid-to-ore ratio is 250 kg / t ore, the temperature is 255℃, and the leaching time is 1 hour. After leaching, the ore is filtered and washed to obtain the leached liquid and the first leaching residue. After leaching, the liquid temperature was 90℃, and oxidation was performed to remove iron, resulting in an oxidized iron-removed slurry with a manganese-to-iron ratio of 1:1. The treatment time was 1 hour, and the potential was 400mV. Magnesium oxide was then used to neutralize and remove iron from the oxidized iron-removed slurry, with the final pH controlled at 3.3 for 3 hours. The iron removal rate was 99.8%. After filtration, iron-removed slag was obtained. The iron-removed slag filter cake was treated with sodium hydroxide solution at 90℃ with a sodium hydroxide solution dosage coefficient of 3 for 3 hours to remove aluminum, resulting in a liquid phase and filter cake. After drying, the filter cake was roasted at 800℃ for 2 hours to obtain the high-iron slag product, hematite, with an iron content of 63%. Magnesium oxide is added to the liquid phase for scandium precipitation, with the final pH controlled at 4.8 for 3 hours, yielding scandium-rich aluminum slag and a post-scandium leaching solution. The scandium-rich aluminum slag filter cake is leached with sodium hydroxide solution at 90℃, with a sodium hydroxide solution dosage coefficient of 4, for 3 hours, yielding scandium-rich slag product and a post-aluminum leaching solution. The post-aluminum leaching solution is used to produce aluminum hydroxide. The post-scandium leaching solution is then subjected to a first-stage nickel-cobalt precipitation using sodium hydroxide at 65℃ for 3 hours, with the final pH controlled at 8.0, yielding MHP product and a post-nickel-cobalt precipitation solution. Magnesium oxide is used to neutralize the post-nickel-cobalt precipitation solution, while compressed air is introduced for a second-stage nickel-cobalt precipitation at 65℃ for 3 hours, with the final pH controlled at 8.5. After precipitation, the solution is thickened to obtain magnesium manganese sulfate solution and nickel-cobalt-manganese slurry. The thickened underflow nickel-cobalt-manganese slurry is returned to the above-mentioned iron removal oxidation step.

[0072] Example 3

[0073] Reference Figure 3 The process flow diagram for improving the processing of laterite nickel ore is as follows:

[0074] The raw material used is limonite-type lateritic nickel ore with a nickel content of 1.2%, cobalt content of 0.12 wt%, iron content of 45%, magnesium content of 2%, manganese content of 0.8 wt%, aluminum content of 1.5 wt%, and scandium content of 40 ppm. High-pressure sulfuric acid leaching was performed at a ratio of 250 kg / t ore to acid, a temperature of 255℃, and a leaching time of 1 hour. After leaching, the ore was filtered and washed to obtain the leaching solution and the first leaching residue. The leaching solution was then fed into a second-stage nickel-cobalt-manganese slurry (nickel-cobalt-manganese slurry) at 90℃ for oxidation and iron removal, resulting in an oxidized iron removal slurry with a manganese-iron ratio of 1:1, a treatment time of 1 hour, and a potential of 400 mV. The oxidized iron removal slurry was further pre-neutralized with magnesium oxide, with the final pH controlled at 1.0, for 3 hours. After filtration, a neutralized residue was obtained. This residue was washed with sodium hydroxide solution at 90℃, with a sodium hydroxide solution dosage coefficient of 3, for 3 hours, yielding the liquid phase and the second leaching residue. Magnesium oxide is added to the liquid phase for a first-stage iron and aluminum removal process, with the final pH controlled at 3.0 for 3 hours, yielding open-circuit iron-aluminum slag and a liquid after the first-stage iron and aluminum removal. Magnesium oxide is then added to the liquid after the first-stage iron and aluminum removal for a second-stage iron and aluminum removal process, with the final pH controlled at 4.0 for 3 hours, yielding second-stage iron-aluminum slag and a liquid after the first-stage iron and aluminum removal. The second-stage iron-aluminum slag is returned to the aforementioned iron removal oxidation step. Sodium hydroxide is used to precipitate nickel and cobalt in the liquid after the iron and aluminum removal process, at 65°C for 3 hours, with the final pH controlled at 8.0, yielding MHP product and a liquid after the first-stage nickel and cobalt precipitation. Magnesium oxide is used to neutralize the liquid after the first-stage nickel and cobalt precipitation, while compressed air is introduced for a second-stage nickel and cobalt precipitation process, at 65°C for 3 hours, with the final pH controlled at 8.5. After precipitation, thickening is performed to obtain magnesium manganese sulfate solution and nickel-cobalt-manganese slurry. The thickened underflow nickel-cobalt-manganese slurry is returned to the aforementioned iron removal oxidation step.

[0075] Example 4

[0076] Reference Figure 4 The process flow diagram for improving the processing of laterite nickel ore is as follows:

[0077] The raw material used is limonite-type lateritic nickel ore with a nickel content of 1.2%, cobalt content of 0.12 wt%, iron content of 45%, magnesium content of 2%, manganese content of 0.8 wt%, aluminum content of 1.5 wt%, and scandium content of 40 ppm. High-pressure sulfuric acid leaching was performed at a ratio of 250 kg / t ore to sulfuric acid, a temperature of 255℃, and a leaching time of 1 hour. After leaching, the ore was filtered and washed to obtain the leaching solution and the first leaching residue. The leaching solution was then circulated at a temperature of 90℃ to obtain a circulating leaching slurry. The circulating leaching slurry was further pre-neutralized with magnesium oxide, with the final pH controlled at 1.0, for 3 hours. After filtration, a neutralized residue was obtained. This residue was then washed with sodium hydroxide solution at 90℃, with a sodium hydroxide solution dosage coefficient of 3, for 3 hours to obtain the liquid phase and the second leaching residue. Magnesium oxide was added to the liquid phase for a first-stage iron and aluminum removal process, with the final pH controlled at 3.0 for 3 hours, yielding open-circuit iron-aluminum slag and a liquid after the first-stage iron and aluminum removal. A second-stage nickel-cobalt-manganese slurry (nickel-cobalt-manganese slurry) with a manganese-to-iron ratio of 1:1 was then introduced, with a treatment time of 1 hour and a potential of 400 mV. This second-stage iron and aluminum removal process was performed on the liquid after the first-stage iron and aluminum removal, with the final pH controlled at 1.0 for 3 hours, yielding a second-stage iron-aluminum slag and a liquid after the iron and aluminum removal process. The second-stage iron-aluminum slag was returned to the oxidation iron removal step. Sodium hydroxide was used to precipitate nickel and cobalt in the liquid after the iron and aluminum removal process, at a temperature of 65°C for 3 hours, with the final pH controlled at 8.0, yielding MHP product and a liquid after the first-stage nickel and cobalt precipitation. Magnesium oxide was used to neutralize the liquid after the first-stage nickel and cobalt precipitation. Simultaneously, compressed air was introduced to precipitate nickel and cobalt in a second stage, at a temperature of 65°C for 3 hours, with the final pH controlled at 8.5. After precipitation, the solution is thickened to obtain magnesium manganese sulfate solution and nickel cobalt manganese slurry. The thickened underflow nickel cobalt manganese slurry is returned to the above-mentioned oxidation and iron removal step.

[0078] Example 5

[0079] The difference from Example 1 is that the molar ratio of ferrous iron in the second-stage nickel-cobalt-manganese ore slurry to ferrous iron in the leaching solution is 5:1, and the final product is MHP.

[0080] Example 6

[0081] The difference from Example 1 is that the molar ratio of ferrous iron in the second-stage nickel-cobalt-manganese ore slurry to ferrous iron in the leaching solution is 0.5:1, and the final product is MHP.

[0082] Example 7

[0083] The difference from Example 1 is that iron was neutralized and removed, and the final pH was controlled at 3.5, ultimately yielding the MHP product.

[0084] Example 8

[0085] The difference from Example 1 is that iron was neutralized and removed, and the final pH was controlled at 3.8, ultimately yielding the MHP product.

[0086] Example 9

[0087] The difference from Example 1 is that the dosage coefficient of sodium hydroxide solution (20wt%) (the dosage of sodium hydroxide solution is based on the stoichiometric ratio of aluminum in the iron slag) is 5, and the final product is MHP.

[0088] Example 10

[0089] The difference from Example 1 is that the dosage coefficient of sodium hydroxide solution (20 wt%) (the dosage of sodium hydroxide solution is based on the stoichiometric ratio of aluminum in the iron slag) is 0.8, and the final product is MHP.

[0090] Example 11

[0091] The difference from Example 1 is that magnesium oxide was added to treat the liquid phase with scandium aluminum precipitation, and the final pH was controlled at 5.2 to obtain the MHP product.

[0092] Example 12

[0093] The difference from Example 1 is that magnesium oxide was added to treat the liquid phase with scandium aluminum precipitation, and the final pH was controlled at 4.3, ultimately yielding the MHP product.

[0094] Example 13

[0095] The difference from Example 1 is that the amount of sodium hydroxide solution used is 1 times the stoichiometric ratio of aluminum in scandium-rich aluminum slag, and the final product is MHP.

[0096] Example 14

[0097] The difference from Example 1 is that the amount of sodium hydroxide solution used is 0.8 times the stoichiometric ratio of aluminum in scandium-rich aluminum slag, and the final product is MHP.

[0098] Example 15

[0099] The difference from Example 1 is that the raw material used is limonite-type lateritic nickel ore with a nickel content of 1.2%, a cobalt content of 0.12 wt%, an iron content of 45%, a magnesium content of 2%, a manganese content of 0.8 wt%, an aluminum content of 1.5 wt%, and a scandium content of 40 ppm. The ore is subjected to high-pressure sulfuric acid leaching at a sulfuric acid-to-ore ratio of 250 kg / t ore, a temperature of 255°C, and a leaching time of 1 hour. After leaching, the leaching solution is filtered and washed to obtain the leaching liquid and the first leaching residue. After leaching, the liquid temperature was 40℃. A second-stage nickel-cobalt-manganese slurry (nickel-cobalt-manganese slurry) was introduced for oxidation and iron removal, resulting in an oxidized iron-removed slurry. The manganese-iron ratio (molar ratio of ferrous iron in the second-stage nickel-cobalt-manganese slurry to that in the leaching liquid) was 5:1. The treatment time was 2 hours, and the potential was 400 mV. Magnesium oxide was then used to neutralize and remove iron from the oxidized iron-removed slurry. The final pH was controlled at 3.5, and the treatment time was 8 hours. The iron removal rate was 99.8%. After filtration, iron-removed slag was obtained. The filter cake was treated with sodium hydroxide solution for aluminum washing at 80℃. The dosage coefficient of the sodium hydroxide solution (30 wt%) (the amount of sodium hydroxide solution was 8 times the stoichiometric ratio of aluminum in the iron-removed slag) was 8, and the treatment time was 3 hours. After washing away the aluminum, a liquid phase and a filter cake were obtained. The filter cake was dried and then roasted at 1000℃ for 2 hours to obtain a high-iron slag product, hematite, with an iron content of 65%. Magnesium oxide was added to the liquid phase for scandium precipitation, with the final pH controlled at 5.0 for 8 hours, yielding scandium-rich aluminum slag and a post-scandium leaching solution. The scandium-rich aluminum slag was then leached with sodium hydroxide solution at 80°C, with a sodium hydroxide solution dosage coefficient (the amount of sodium hydroxide solution was 8 times the stoichiometric ratio of aluminum in the scandium-rich aluminum slag) of 8, for 8 hours, yielding scandium-rich slag product and a post-aluminum leaching solution. The post-aluminum leaching solution was used to produce aluminum hydroxide. The post-scandium leaching solution was then subjected to a first-stage nickel-cobalt precipitation with sodium hydroxide at 65°C for 3 hours, with the final pH controlled at 7.0, yielding an MHP product and a post-nickel-cobalt precipitation solution. Magnesium oxide was then used to neutralize the post-nickel-cobalt precipitation solution, while compressed air was introduced for a second-stage nickel-cobalt precipitation at 45°C for 5 hours, with the final pH controlled at 9.0. After precipitation, the solution is thickened to obtain magnesium manganese sulfate solution and nickel cobalt manganese slurry. The thickened underflow nickel cobalt manganese slurry is returned to the above-mentioned oxidation and iron removal step.

[0100] Example 16

[0101] The difference from Example 3 is that the raw material used is limonite-type lateritic nickel ore with a nickel content of 1.2%, a cobalt content of 0.12 wt%, an iron content of 45%, a magnesium content of 2%, a manganese content of 0.8 wt%, an aluminum content of 1.5 wt%, and a scandium content of 40 ppm. The ore is subjected to high-pressure sulfuric acid leaching at a sulfuric acid-to-ore ratio of 400 kg / t ore, a temperature of 255°C, and a leaching time of 1 hour. After leaching, the leaching solution is filtered and washed to obtain the leaching liquid and the first leaching residue. After leaching, the solution temperature is 40℃. A second-stage nickel-cobalt-manganese slurry (nickel-cobalt-manganese slurry) is added for oxidation and iron removal, resulting in an oxidized iron-removed slurry. The manganese-to-iron ratio (molar ratio of manganese in the nickel-cobalt-manganese slurry to ferrous iron in the first-stage iron-aluminum removal solution) is 5:1. The treatment time is 1 hour, and the potential is 400 mV. Magnesium oxide is then used to pre-neutralize the oxidized iron-removed slurry, with the final pH controlled at 2.0 for 5 hours. After filtration, a neutralized residue is obtained. This residue is washed with sodium hydroxide solution at 100℃, with a sodium hydroxide solution dosage coefficient of 3, for 3 hours, yielding a liquid phase and a second leaching residue. Magnesium oxide is then added to the liquid phase for a first-stage iron-aluminum removal, with the final pH controlled at 4.0 for 5 hours, resulting in an open-circuit iron-aluminum slag and a first-stage iron-aluminum removal solution. Magnesium oxide is then added to the first-stage iron-aluminum removal solution for a second-stage iron-aluminum removal, with the final pH controlled at 5.0 for 5 hours, yielding a second-stage iron-aluminum slag and a second-stage iron-aluminum removal solution. The second-stage iron-aluminum slag is returned to the oxidation and iron removal step. Sodium hydroxide is used to precipitate nickel and cobalt in the liquid after iron and aluminum removal at 65°C for 3 hours, with the final pH controlled at 7.0, yielding MHP product and the liquid after the first-stage nickel-cobalt precipitation. Magnesium oxide is then used to neutralize the liquid after the first-stage nickel-cobalt precipitation. Simultaneously, compressed air is introduced to precipitate nickel and cobalt in a second stage at 65°C for 3 hours, with the final pH controlled at 9.0. After precipitation, thickening is performed to obtain magnesium manganese sulfate solution and nickel-cobalt-manganese slurry. The thickened underflow nickel-cobalt-manganese slurry is returned to the oxidation and iron removal step.

[0102] Example 17

[0103] The difference from Example 4 is that the raw material used is limonite-type lateritic nickel ore with a nickel content of 1.2%, a cobalt content of 0.12 wt%, an iron content of 45%, a magnesium content of 2%, a manganese content of 0.8 wt%, an aluminum content of 1.5 wt%, and a scandium content of 40 ppm. After high-pressure sulfuric acid leaching at a ratio of 250 kg / t ore, a temperature of 255°C, and a leaching time of 1 hour, the leaching solution is filtered and washed to obtain the leaching liquid and the first leaching residue. The leaching liquid is then circulated at a temperature of 90°C to obtain a circulating leaching slurry. The circulating leaching slurry is further pre-neutralized with magnesium oxide, with the final pH controlled at 1.5 for 3 hours. After filtration, a neutralized residue is obtained. This neutralized residue is washed with sodium hydroxide solution at 90°C with a sodium hydroxide solution dosage coefficient of 3 for 5 hours to obtain the liquid phase and the second leaching residue. Magnesium oxide was added to the liquid phase for a first-stage iron and aluminum removal process, with the final pH controlled at 4.0 for 5 hours, yielding open-circuit iron-aluminum slag and a liquid after the first-stage iron and aluminum removal. A second-stage nickel-cobalt-manganese slurry (nickel-cobalt-manganese slurry) with a manganese-to-iron ratio of 1:1 was then introduced, with a treatment time of 1 hour and a potential of 400 mV, to perform a second-stage iron and aluminum removal process, with the final pH controlled at 5.0 for 5 hours, yielding a second-stage iron-aluminum slag and a liquid after the first-stage iron and aluminum removal. The second-stage iron-aluminum slag was returned to the oxidation iron removal step. Sodium hydroxide was used to precipitate nickel and cobalt in the liquid after the iron and aluminum removal process, at 65°C for 3 hours, with the final pH controlled at 7.0, yielding MHP product and a liquid after the first-stage nickel and cobalt precipitation. Magnesium oxide was used to neutralize the liquid after the first-stage nickel and cobalt precipitation, while compressed air was introduced for a second-stage nickel and cobalt precipitation process, at 65°C for 3 hours, with the final pH controlled at 9.0. After precipitation, the solution is thickened to obtain magnesium manganese sulfate solution and nickel cobalt manganese slurry. The thickened underflow nickel cobalt manganese slurry is returned to the above-mentioned oxidation and iron removal step.

[0104] The nickel content, cobalt content, and scandium recovery rate of the MHP products in the above examples were tested, and the test data are listed in Table 1.

[0105] Table 1

[0106] Example 1 40.1 4.0 80.2 Example 2 40.2 4.2 80.5 Example 3 40.3 4.1 40.1 Example 4 40.2 4.2 40.0 Example 5 40.1 4.1 80.2 Example 6 40.3 4.2 80.2 Example 7 40.2 4.2 75.2 Example 8 40.5 4.1 70.2 Example 9 40.2 4.3 80.3 Example 10 40.1 4.0 80.1 Example 11 40.4 4.0 88.0 Example 12 39.1 3.5 75.2 Example 13 40.1 4.0 80.0 Example 14 40.5 4.4 80.2 Example 15 40.3 4.5 80.2 Example 16 40.2 4.2 40.1 Example 17 40.0 4.1 40.3

[0107] It should be noted that the purity of both the MHP product and the scandium residue in Example 6 was slightly reduced.

[0108] The purity of nickel and cobalt in Examples 10 and 12 was slightly reduced.

[0109] The recovery rate of nickel and cobalt was slightly reduced in Example 11.

[0110] The aluminum content in the high-iron slag in Example 14 was slightly higher than normal.

[0111] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0112] Traditional processes utilize compressed air to oxidize ferrous iron (Fe2+), resulting in low efficiency (less than 3% utilization) and energy waste. This application uses manganese-containing substances as an oxidant to oxidize ferrous iron (Fe2+) to ferric iron (Fe3+). This not only solves the problems of slow oxidation rate and compressed air waste at low pH, improving oxidation efficiency and manganese utilization, but also allows ferric iron to precipitate at lower pH, reducing aluminum and scandium precipitation and achieving effective separation of iron and aluminum / scandium, thus improving scandium recovery. Furthermore, there are four specific methods for oxidizing ferrous iron to ferric iron, which can be found in [reference needed]. Figures 1 to 4 The difference in process lies in step S2. It is evident that the main effects of the improved treatment method for laterite nickel ore are: significantly improved efficiency of ferrous iron oxidation and manganese utilization, reduced use of compressed air or oxygen, reduced electricity consumption, and lower production costs; effective iron recovery reduces slag rate and tailings pond usage, greatly reducing environmental safety hazards and pollution; effective separation of iron, aluminum, and scandium is achieved, improving scandium and aluminum recovery rates, while also enhancing nickel and cobalt recovery rates and product quality; this method provides four process routes, enhancing the adaptability and flexibility of the process.

[0113] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An improved processing method for laterite nickel ore, wherein the laterite nickel ore is a mixture of limonite-type laterite nickel ore and residual laterite nickel ore in any proportion, characterized in that, The improved processing method includes: Step S1: The laterite nickel ore is acid-leached, filtered, and washed to obtain leaching solution and first leaching residue. Step S2, wherein step S2 is selected from any one of steps S2-1, S2-2, and S2-3; Step S2-1: The leaching solution is oxidized and iron-removed using a manganese-containing substance to obtain an oxidized iron-removed slurry; the oxidized iron-removed slurry is then neutralized and iron-removed sequentially using an iron-removing neutralizing agent, followed by liquid-solid separation to obtain iron-removed slag; the iron-removed slag is then treated with aluminum-washing alkaline solution to obtain a liquid phase and a high-iron slag product; the iron content in the high-iron slag product is 55%~65%; the liquid phase is then treated with an aluminum-scandium precipitation neutralizing agent to obtain scandium-rich aluminum slag and a scandium-removed solution; the scandium-rich aluminum slag is then treated with an aluminum-leaching alkaline solution to obtain a scandium-rich slag product and an aluminum-leaching solution; wherein, the final pH of the iron-removing neutralization is 2.8~3.

5. Step S2-2: The leaching solution is oxidized to remove iron using a manganese-containing substance to obtain an oxidized iron-removed slurry; the oxidized iron-removed slurry is pre-neutralized and then subjected to liquid-solid separation using a pre-neutralizing agent to obtain a neutralized residue; the neutralized residue is washed to obtain a liquid phase and a second leaching residue; the liquid phase is subjected to a first-stage iron-aluminum removal neutralizing agent to remove iron and aluminum in the first stage, resulting in an open-circuit iron-aluminum residue and a first-stage iron-aluminum removal solution; the first-stage iron-aluminum removal solution is subjected to a second-stage iron-aluminum removal neutralizing agent to remove iron and aluminum in the second stage, resulting in a second-stage iron-aluminum residue and a second-stage iron-aluminum removal solution; the second-stage iron-aluminum residue is returned to the oxidized iron removal step; wherein, the final pH of the pre-neutralization is 1-2; the final pH of the first-stage iron-aluminum removal is 3-4; and the final pH of the second-stage iron-aluminum removal is 4-5. Step S2-3: The leaching solution is circulated for leaching to obtain a circulating leaching slurry; the circulating leaching slurry is pre-neutralized and then subjected to liquid-solid separation using a pre-neutralizing agent to obtain a neutralized residue; the neutralized residue is washed to obtain a liquid phase and a second leaching residue; the liquid phase is subjected to a first-stage iron and aluminum removal neutralizing agent to obtain an open-circuit iron and aluminum residue and a first-stage iron and aluminum removal solution; the first-stage iron and aluminum removal solution is subjected to a second-stage iron and aluminum removal using a manganese-containing substance to obtain a second-stage iron and aluminum residue and a second-stage iron and aluminum removal solution; the second-stage iron and aluminum residue is returned to the circulating leaching step; wherein, the final pH of the pre-neutralization is 1-2; the final pH of the first-stage iron and aluminum removal is 3-4; and the final pH of the second-stage iron and aluminum removal is 4-5. Step S3: Use a precipitant to precipitate nickel and cobalt in the solution after removing aluminum and scandium or the solution after removing iron and aluminum, and perform a first-stage precipitation of nickel and cobalt and dense filtration to obtain a solution after first-stage precipitation of nickel and cobalt and nickel and cobalt hydroxide product. Step S4: Use a nickel-cobalt neutralizing agent and an oxidizing agent to perform a second-stage precipitation of nickel-cobalt in the liquid after the first-stage precipitation of nickel-cobalt, to obtain magnesium-manganese sulfate solution and nickel-cobalt-manganese slurry; In step S2-1, the mass concentration of the aluminum washing alkaline solution is 0.1wt%~40wt%, and the amount of the aluminum washing alkaline solution used is 0.8~8 times the stoichiometric ratio of aluminum in the iron removal slag. The manganese-containing substance is the nickel-cobalt-manganese slurry in step S4; in step S2-1, the molar ratio of manganese in the manganese-containing substance to ferrous iron in the leaching solution is 0.5~5:1; The raw material laterite nickel ore contains 0.8~1.5wt% nickel, 0.01~0.3wt% cobalt, 40~45wt% iron, 0.5~5wt% magnesium, 0.5~2wt% manganese, 0.5~4wt% aluminum, and 20~80ppm scandium.

2. The improved processing method according to claim 1, characterized in that, In step S2-1, the temperature for iron removal by oxidation is 25℃~100℃, and the time for iron removal by oxidation is 0.1h~5h.

3. The improved processing method according to claim 1, characterized in that, In step S2-1, the temperature for neutralization and iron removal is 25℃~100℃, and the time for neutralization and iron removal is 0.5h~8h. The iron-removing 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, calcium hydroxide, magnesium hydroxide, calcium carbonate, calcium bicarbonate, limestone, magnesia powder, magnesite, dolomite, and marble.

4. The improved processing method according to claim 1, characterized in that, The aluminum washing process is carried out at a temperature of 25℃ to 100℃ for a duration of 0.5 h to 8 h. And / or, the magnesium manganese sulfate solution is returned to step S2-1 as the aluminum washing alkali solution.

5. The improved processing method according to claim 1, characterized in that, In step S2-1, the endpoint pH of the scandium plating treatment is 4.5~5.2, the temperature of the scandium plating treatment is 25℃~100℃, and the treatment time is 0.5h~8h. And / or, the scandium-containing aluminum 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, calcium hydroxide, magnesium hydroxide, calcium carbonate, calcium bicarbonate, limestone, magnesia powder, magnesite, dolomite, and marble.

6. The improved processing method according to claim 1, characterized in that, Step S2-1 further includes: The iron slag obtained from the aluminum washing process is sequentially dried and roasted to obtain the high-iron slag product; wherein the roasting temperature is 500℃~1200℃ and the roasting time is 1min~5h.

7. The improved processing method according to claim 1, characterized in that, In step S2-2, the temperature for iron removal by oxidation is 25℃~100℃, and the time for iron removal by oxidation is 0.1h~5h.

8. The improved processing method according to claim 1, characterized in that, In step S2-2, the pre-neutralizing agent, the first-stage iron and aluminum removal neutralizing agent, and the second-stage iron and aluminum removal neutralizing agent are each independently 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, calcium hydroxide, magnesium hydroxide, calcium carbonate, calcium bicarbonate, limestone, magnesite powder, magnesite, dolomite, and marble. And / or, the pre-neutralization temperature is 25℃~100℃, and the pre-neutralization time is 0.5h~8h; And / or, the temperature for removing iron and aluminum in the first stage is 25℃~100℃, and the time for removing iron and aluminum in the first stage is 0.5h~8h; And / or, the temperature for the two-stage iron and aluminum removal is 25℃~100℃, and the time for the two-stage iron and aluminum removal is 0.5h~8h.

9. The improved processing method according to claim 1, characterized in that, In steps S2-3, the molar ratio of manganese in the manganese-containing substance to divalent iron in the liquid after iron and aluminum removal is 0.1~10:

1.

10. The improved processing method according to claim 1, characterized in that, In steps S2-3, the pre-neutralizing agent and the first-stage iron and aluminum removal neutralizing agent are each independently 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, calcium hydroxide, magnesium hydroxide, calcium carbonate, calcium bicarbonate, limestone, magnesia powder, magnesite, dolomite, and marble; And / or, the pre-neutralization temperature is 25℃~100℃, and the pre-neutralization time is 0.5h~8h; And / or, the temperature for removing iron and aluminum in the first stage is 25℃~100℃, and the time for removing iron and aluminum in the first stage is 0.5h~8h; And / or, the temperature of the two-stage iron and aluminum removal is 25℃~100℃, and the time of the two-stage iron and aluminum removal is 0.1h~5h.

11. The improved processing method according to claim 1, characterized in that, In step S3, the final pH of the first stage of nickel-cobalt precipitation is 7.0~8.0, the temperature of the first stage of nickel-cobalt precipitation is 25℃~100℃, and the time of the first stage of nickel-cobalt precipitation is 0.5h~8h. The precipitant is selected from any one or more of magnesium oxide, sodium hydroxide, and calcium hydroxide.

12. The improved processing method according to claim 1, characterized in that, In step S4, the endpoint pH of the two-stage nickel-cobalt precipitation is 8.0~9.0, the temperature of the two-stage nickel-cobalt precipitation is 25℃~100℃, and the time of the two-stage nickel-cobalt precipitation is 0.5h~8h. And / or, the nickel-cobalt 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, calcium hydroxide, magnesium hydroxide, calcium carbonate, and calcium bicarbonate. And / or, the oxidant is selected from any one or more of the following: a mixture of sulfur dioxide and oxygen, oxygen, compressed air, oxygen-enriched water, hydrogen peroxide, sodium persulfate, potassium persulfate, and potassium permanganate.

13. The improved processing method according to claim 1, characterized in that, In step S1, the acid leaching temperature is 80℃~280℃, the acid leaching time is 0.1~10h, and the acid-to-ore ratio is 200~400kg / t ore.

14. The improved processing method according to claim 1, characterized in that, The mass concentration of the aluminum immersion alkaline solution is 0.1wt%~40wt%, and the amount of the aluminum immersion alkaline solution used is 0.8~8 times the stoichiometric ratio of aluminum in the scandium-rich aluminum slag. And / or, the temperature of the aluminum immersion treatment is 25℃~100℃, and the time of the aluminum immersion treatment is 0.5 h~8 h; And / or, the aluminum immersion liquid is recycled and used as the aluminum immersion alkaline solution.

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