A MHP short-process process for preparing nickel-cobalt-manganese purified liquid

Abstract

The invention discloses a MHP short-process process for preparing a nickel-cobalt-manganese purified solution, belonging to the field of hydrometallurgy technology. The process comprises: drying nickel-cobalt hydroxide raw materials; slurrying, reduction leaching, and separation to obtain a preliminarily purified nickel-cobalt-manganese solution and manganese-containing slag; acidification and leaching of the manganese-containing slag to obtain manganese-silicon slag and a nickel-containing pickling solution; adding a neutralizer to the preliminarily purified nickel-cobalt-manganese solution to adjust the pH, adding an oxidizer, and separating a filtrate and a filter residue; adding concentrated sulfuric acid to the filter residue for aging and leaching to obtain aging leaching residue and a desiliconized filtrate; returning the aging leaching residue for reduction leaching; adding a second neutralizer to the desiliconized filtrate to adjust the pH, reacting, and separating iron-aluminum slag and a nickel-containing impurity-removed filtrate; adding a third neutralizer to the nickel-containing impurity-removed filtrate to adjust the pH and precipitate nickel to obtain nickel-containing alkaline substances; and removing impurities from the filtrate to obtain a nickel-cobalt-manganese purified solution. The present invention can obtain nickel-cobalt-manganese purified liquid, scandium-containing iron-aluminum slag, by-product manganese-silicon slag, etc., thereby achieving solid waste reduction and high value-added, which is more economical, more efficient and more environmentally friendly.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrometallurgy, and in particular to a MHP short-process process for preparing nickel-cobalt-manganese purified liquid. Background Art

[0002] Laterite nickel ore has become a major source of nickel raw materials due to its abundant reserves, ease of mining, and low mining costs. Nickel-cobalt hydroxide, derived from laterite nickel ore, is becoming a key raw material for the production of ternary precursors for batteries (such as cathode composite materials) due to its lower price compared to nickel raw materials derived from sulfide nickel ore. This nickel-cobalt hydroxide contains impurities such as iron, aluminum, manganese, magnesium, and silicon, in addition to nickel and cobalt.

[0003] The current traditional treatment method involves slurrying and dissolving nickel-cobalt hydroxide materials, extracting and removing impurities, and purifying them for reuse. However, the leaching process for nickel-cobalt hydroxide is lengthy and complex (requiring multiple steps such as leaching, extraction, stripping, and precipitation), resulting in a production cycle of up to 10 days and high equipment investment costs (over 16,000 yuan per ton). Furthermore, the reliance on a large number of chemical reagents (such as the extractant P204) not only drives up operating costs but also produces highly concentrated phosphorus-containing wastewater (8 tons per ton of product), with environmental treatment costs as high as 200 yuan per ton. Furthermore, significant amounts of silicon are dissolved during the treatment process, affecting subsequent extraction processes and resulting in low nickel-cobalt recovery rates, making it difficult to meet the stringent purity requirements of high-nickel ternary materials (such as NCM811). With the growth of ternary power batteries, the application of nickel in power batteries is booming. The industry is focusing on how to process the nickel-cobalt hydroxide intermediate product through more economical and efficient hydrometallurgical processes.

[0004] Chinese application CN112210679A discloses a method for preparing nickel sulfate from nickel cobalt hydroxide. Unlike the traditional nickel-cobalt separation process, after the reduction acid leaching process, it uses catalytic oxidation to separate cobalt, manganese and iron from nickel, and simultaneously uses neutralization reaction to separate impurity elements such as scandium, aluminum and chromium. The variable valence metals such as manganese, cobalt and iron are separated by chemical precipitation at the front end. The first impurity removal solution obtained is almost pure and has a very low impurity content. This greatly reduces the amount of subsequent extraction and impurity removal and nickel-cobalt separation and extraction systems, and the subsequent deep extraction and impurity removal system is greatly reduced, effectively simplifying the preparation process of nickel sulfate. However, there is still an extraction process, which uses organic solvents and pollutes the environment.

[0005] Chinese application CN116334389A discloses a method for leaching and purifying an intermediate product of nickel, cobalt, and manganese hydroxide from laterite nickel ore. Through specific acid leaching and pH adjustment steps, the recovery rate of valuable metals is improved, acid and alkali consumption and processing costs are reduced, and material losses are minimized. Subsequent extraction steps are also required.

[0006] Therefore, how to process nickel cobalt hydroxide intermediate products more economically, efficiently and environmentally friendly still needs further improvement. Summary of the Invention

[0007] The inventors of this application have discovered and recognized that existing nickel cobalt hydroxide (MHP) raw material processing processes have at least the following problems: uncontrollable manganese leaching during leaching, making filtration difficult; difficulty in directional separation of siliceous components; the traditional calcium-based neutralization process produces high-nickel iron-aluminum slag, resulting in high solid waste disposal costs and low resource utilization; the extraction and purification process is difficult to efficiently remove impurity ions (calcium, magnesium, copper, zinc, silicon, etc.), affecting product quality, and the extraction and impurity removal system requires high flow rates; the process is lengthy, inefficient, and severely polluting. This application is based on the inventors' discoveries and understanding of these facts and problems. The present invention aims to address, to at least some extent, one of the aforementioned technical problems in the related art.

[0008] To this end, according to one embodiment of the present invention, a MHP short-process process for preparing nickel-cobalt-manganese purified liquid is proposed, the process comprising the following steps:

[0009] High-temperature steam is used to dry the nickel-cobalt hydroxide raw materials;

[0010] The dried nickel-cobalt hydroxide raw material is slurried, and after slurrying, reduction leaching is performed, the amount of reducing agent added is controlled, the leaching rate of manganese is controlled, and solid-liquid separation is performed to obtain a preliminarily purified nickel-cobalt-manganese solution and manganese-containing slag;

[0011] Acid leaching is performed on the manganese-containing slag, and solid-liquid separation is performed to obtain manganese silicon slag and a nickel-containing pickling solution;

[0012] adding a first neutralizing agent to the preliminarily purified nickel-cobalt-manganese solution to adjust the pH, adding an oxidizing agent to react, and performing solid-liquid separation to obtain a filtrate and a filter residue;

[0013] Adding concentrated sulfuric acid to the filter residue for ripening and leaching, and separating the solid and liquid to obtain ripened leaching residue and desiliconized filtrate; returning the ripened leaching residue to the reduction leaching stage;

[0014] Adding a second neutralizing agent to the desiliconization filtrate to adjust the pH, reacting, and performing solid-liquid separation to obtain iron-aluminum slag and a nickel-containing impurity-removed filtrate; adding a third neutralizing agent to the nickel-containing impurity-removed filtrate to adjust the pH to perform a nickel precipitation reaction, and performing solid-liquid separation to obtain a nickel-containing alkaline substance;

[0015] Calcium, magnesium, silicon, copper and zinc impurities are removed from the filtrate to obtain a nickel-cobalt-manganese purified solution.

[0016] Optionally, when high-temperature steam is used to dry the nickel cobalt hydroxide raw material, the raw material is dried to a moisture content of less than 10%.

[0017] Optionally, the dried nickel cobalt hydroxide raw material is slurried, and in the reduction leaching step after slurrying, the reducing agent is one of H2O2, SO2, and Na2SO3.

[0018] Optionally, the amount of reducing agent is controlled as follows: the amount of reducing agent / Mn content of the ore is 0.2 to 1 mol / mol.

[0019] Optionally, the dried nickel cobalt hydroxide raw material is slurried, and in the step of reduction leaching after slurrying, the slurrying process is as follows: the liquid-solid ratio is 2 to 4:1, the reaction temperature is 60 to 90°C, the end point pH is 4.0 to 5.5, the stirring speed is 300 to 800 r / min, and the reaction time is 2 to 4 hours.

[0020] Optionally, the dried nickel cobalt hydroxide raw material is slurried, and in the step of reduction leaching after slurrying, the reduction leaching process is: liquid-solid ratio is 4-6:1, reaction temperature is 60-90°C, endpoint pH is 1-2, stirring speed is 300-800r / min, and reaction time is 1.5-3h.

[0021] Optionally, when the manganese-containing slag is subjected to acid leaching, the liquid-to-solid ratio is 4-6:1, the temperature is 70-90° C., the pH is adjusted to 0.8-1.5, and the reaction is carried out for 3-5 hours;

[0022] Optionally, the method further comprises: returning the nickel-containing pickling solution to the reduction leaching stage.

[0023] Optionally, a first neutralizing agent is added to adjust the pH to 4.5-5.2.

[0024] Optionally, the first neutralizing agent is a nickel-cobalt hydroxide raw material, or a nickel-containing alkaline substance obtained by reacting the nickel-cobalt hydroxide raw material with nickel precipitation. Preferably, the first neutralizing agent is a nickel-containing alkaline substance obtained by reacting the nickel-cobalt hydroxide raw material with nickel precipitation.

[0025] Optionally, when an oxidant is added for reaction, the temperature is 60-90° C., the stirring speed is 300-800 r / min, and the reaction time is 3-5 h.

[0026] Optionally, the oxidant is air or H2O2.

[0027] Optionally, in the mature leaching process, the acid-ore ratio is 500-900 kg / t, stirring is 1-3 hours, and then water is added to the liquid-solid ratio of 3-10:1, the temperature is 80-95° C., and the stirring speed is 300-800 r / min.

[0028] Optionally, a second neutralizing agent is added to adjust the pH to 3.5-4.0, the reaction time is 3-5 hours, and the reaction temperature is 40-70°C.

[0029] Optionally, the second neutralizing agent is a nickel cobalt hydroxide raw material and / or Na2CO3. Preferably, the second neutralizing agent is a nickel cobalt hydroxide raw material and Na2CO3.

[0030] Optionally, the third neutralizing agent is Na2CO3. Further optionally, the third neutralizing agent is added to adjust the pH to 7-8 to carry out nickel precipitation reaction, the reaction temperature is 40-70°C, and the reaction time is 2-4 hours to obtain Na2SO4 solution and nickel-containing alkaline substance NiCO3.

[0031] Optionally, the Na2SO4 solution is subjected to evaporation and crystallization treatment to obtain a by-product of Glauber's salt.

[0032] Optionally, calcium, magnesium, silicon, copper and zinc impurities in the filtrate are removed in sequence to obtain a nickel-cobalt-manganese purified liquid; wherein manganese fluoride is used to remove calcium and magnesium; polyferric sulfate is used to remove silicon; manganese powder or iron powder is used to remove copper; and nickel sulfide is used to remove zinc.

[0033] Optionally, removing calcium, magnesium, silicon, copper and zinc impurities in the filtrate in sequence comprises the following steps:

[0034] Calcium and magnesium removal: Mix the filtrate with MnF and stir for 0.5 to 1 hour. The reaction temperature is 60 to 80°C and the MnF dosage coefficient is 1 to 3 mol / mol. After the reaction, solid-liquid separation is performed to obtain calcium and magnesium removal filtrate and calcium and magnesium slag.

[0035] Desiliconization: Mix the calcium and magnesium removal filtrate with polyferric sulfate, stir for 0.5 to 2 hours, the reaction temperature is 40 to 60 ° C, the polyferric sulfate dosage coefficient PFS / SiO2 is 80 to 120 wt% / wt.%, and then separate the solid and liquid to obtain silicon slag and desiliconization filtrate;

[0036] Copper removal: The desiliconization filtrate is pumped into a copper removal tank, heated to 40-60°C, the manganese powder dosage coefficient is 1-2 mol / mol, and the reaction is carried out for 1-3 hours. After the reaction, the solid and liquid are separated to obtain copper slag and copper removal filtrate;

[0037] Zinc removal: The copper removal filtrate is pumped into a zinc removal tank, heated to 40-50°C, sulfuric acid is added to adjust the pH to 4-6, the reaction time is 1-2 hours, the nickel sulfide dosage coefficient is 1-1.2 mol / mol, and then solid-liquid separation is performed to obtain zinc slag and nickel-cobalt-manganese purified liquid.

[0038] Optionally, in the process, the nickel and cobalt leaching rate is ≥98%, and the manganese leaching rate can be controlled in the range of 35% to 99%.

[0039] Optionally, the concentration of key impurities in the nickel-cobalt-manganese purification solution is lower than 50 ppm; the key impurities include calcium, magnesium, copper, zinc and silicon.

[0040] Beneficial Effects: According to one embodiment of the present invention, a process for preparing a purified nickel-cobalt-manganese solution using MHP (MHP) is provided. This innovative leaching-neutralization-precipitation process utilizes MHP as the raw material, achieving efficient dissolution of nickel, cobalt, and manganese by precisely controlling leaching conditions. Neutralization and directional precipitation are combined to simultaneously remove impurities, resulting in a one-step process for producing a high-purity nickel-cobalt-manganese solution. This process completely eliminates the traditional extraction process, promoting the development of my country's nickel-cobalt resources towards a shorter, higher-value-added process, and providing core support for cost reduction and efficiency improvement in the new energy industry chain.

[0041] Compared with the prior art, some embodiments of the present invention also have the following advantages:

[0042] 1. This invention utilizes a high-temperature pretreatment-staged acid control-redox synergistic leaching technology. High-temperature pretreatment is used to achieve siliceous crystal transformation, significantly improving the filtration performance of the leachate. Staged acid control is used to regulate the valence of manganese, and by adjusting the amount of reducing agent, controllable manganese leaching is achieved while simultaneously improving nickel and cobalt leaching, paving the way for subsequent market demand for different nickel, cobalt, and manganese ratios.

[0043] 2. The present invention utilizes slag acid aging and a two-stage gradient neutralization and precipitation process to selectively precipitate iron and aluminum ions, producing scandium-containing iron and aluminum slag and reusable high-nickel-containing alkaline materials, thereby realizing waste resource utilization. In some embodiments, the alkalinity of nickel and cobalt hydroxide in MHP and the NiCO3 generated in subsequent steps are utilized to achieve selective precipitation of iron and aluminum ions, effectively suppressing the introduction of calcium and magnesium ions. Through secondary removal of silicon impurities and an innovative two-stage gradient neutralization process, scandium-containing iron and aluminum slag, reusable high-nickel-containing alkaline materials, and high-purity sodium sulfate are obtained, realizing waste resource utilization.

[0044] 3. In some embodiments of the present invention, the obtained filtrate is purified by using manganese fluoride to remove calcium and magnesium, manganese powder and iron powder to remove copper, nickel sulfide to remove zinc, and polyferric sulfate to remove silicon. This breaks through the limit of traditional purification processes for removing trace impurities, and makes the concentration of key impurities in the nickel-cobalt-manganese purified liquid lower than 50ppm, which can be directly used for the preparation of ternary precursors.

[0045] 4. The MHP short-process process for preparing nickel-cobalt-manganese purified liquid proposed in this invention offers the advantages of greater economy, efficiency, and environmental friendliness. High efficiency: nickel-cobalt leaching rates ≥ 98%, and manganese leaching rates within a controllable range of 35% to 99%. Environmental friendliness: Solid waste is reutilized, reducing environmental pollution. Economical: The short process design reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 The present invention is a flowchart of a process for preparing nickel-cobalt-manganese purified liquid by MHP short process in one embodiment of the present invention. DETAILED DESCRIPTION

[0047] To better illustrate this application and facilitate understanding of the technical solutions of the present invention, the present invention is described in further detail below. Obviously, the following embodiments are only some embodiments of the present invention, rather than all embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0048] In one embodiment of the present application, a MHP short-process process for preparing nickel-cobalt-manganese purified liquid is provided, comprising the following steps:

[0049] (1) Using high-temperature steam to dry the nickel cobalt hydroxide raw material;

[0050] (2) Slurrying the dried nickel cobalt hydroxide raw material, performing reduction leaching after slurrying, controlling the amount of reducing agent added, controlling the manganese leaching rate, and performing solid-liquid separation to obtain a preliminarily purified nickel cobalt manganese solution and manganese-containing slag;

[0051] (3) acidifying and leaching the manganese-containing slag, and performing solid-liquid separation to obtain manganese silicon slag and a nickel-containing pickling solution;

[0052] (4) adding a first neutralizing agent to the preliminarily purified nickel-cobalt-manganese solution to adjust the pH, adding an oxidizing agent to react, and performing solid-liquid separation to obtain a filtrate and a filter residue;

[0053] (5) adding concentrated sulfuric acid to the filter residue for ripening and leaching, and separating the solid and liquid to obtain ripened leaching residue and desiliconized filtrate; returning the ripened leaching residue to step 2);

[0054] (6) adding a second neutralizing agent to the desiliconization filtrate to adjust the pH, reacting, and performing solid-liquid separation to obtain iron-aluminum slag and nickel-containing impurity-removed filtrate; adding a third neutralizing agent to the nickel-containing impurity-removed filtrate to adjust the pH and perform nickel precipitation reaction to obtain nickel-containing alkaline substance;

[0055] (7) removing calcium, magnesium, silicon, copper and zinc impurities from the filtrate to obtain a purified nickel-cobalt-manganese solution.

[0056] In some embodiments of the present invention, a siliceous crystallization-staged acid control-redox synergistic leaching technique is employed to obtain a pre-purified, easily filterable nickel-cobalt-manganese impure solution and a high-manganese-rich slag. During post-neutralization, iron and aluminum removal, and harmless treatment of the iron-aluminum slag, an MHP self-circulating neutralization and control system is constructed. Using processes such as slag acid maturation and secondary precipitation, scandium-containing iron-aluminum slag, recyclable high-nickel alkaline materials, and high-purity Glauber's saltpeter are obtained, achieving both solid waste reduction and increased value creation. Finally, during the deep purification and impurity removal of the neutralized solution, multi-scale interface control is employed to achieve precise targeted removal of impurity ions, resulting in a nickel-cobalt-manganese solution with a critical impurity concentration below 50 ppm, suitable for direct use in ternary precursor preparation.

[0057] In step (1) of the present invention, a siliceous crystal transformation is achieved by utilizing high-temperature pretreatment, thereby significantly improving the filtration performance of the subsequent leachate. Furthermore, the nickel cobalt hydroxide raw material is dried using high-temperature steam to a moisture content of less than 10%. Furthermore, it can be dried to the point where no moisture is present, thereby maximizing the improvement in the filtration performance of the leachate. In addition, the high-temperature steam can be the residual high-temperature steam from the three-stage preheating and three-stage flash evaporation processes in the laterite nickel ore leaching plant, or the high-temperature steam generated in the sulfuric acid production process. In this way, the excess high-temperature steam is recycled and utilized; the nickel cobalt hydroxide raw material dried in the step is transported over long distances, thereby reducing transportation costs.

[0058] In step (2) of the present invention, based on the raw materials after high-temperature pretreatment, the manganese leaching is controlled by staged acid control (pulping and reduction), thereby obtaining a high-manganese-containing slag (the high-manganese-containing slag is then converted into a manganese silicon slag product that can be sold externally through acidification), and at the same time obtaining a preliminarily purified and easily filterable nickel-cobalt-manganese impurity solution, and subsequently selective precipitation of iron and aluminum ions is carried out based on the nickel-cobalt-manganese solution.

[0059] In some preferred embodiments, the slurrying process is as follows: first, water is added to the dried nickel cobalt hydroxide raw material to adjust the liquid-solid ratio to 2-4:1, and then concentrated sulfuric acid is added to adjust the end point pH to 4.0-5.5, the reaction temperature is 60-90°C, the stirring speed is 300-800r / min, and the reaction time is 2-4h.

[0060] In some preferred embodiments, the reduction leaching process has a liquid-to-solid ratio of 4 to 6:1, a reaction temperature of 60 to 90°C, an endpoint pH of 1 to 2, a stirring speed of 300 to 800 rpm, and a reaction time of 1.5 to 3 hours. The reducing agent is one of H₂O₂, SO₂, or Na₂SO₃. Preferably, the reducing agent coefficient (reducing agent dosage / ore Mn content) is 0.2 to 1 mol / mol.

[0061] The preferred embodiment, based on staged acid control, precisely regulates the pH during slurrying and reduction leaching (i.e., adjusting the pH to 4.0-5.5 during the slurrying stage and then to 1-2 during the reduction leaching stage). This allows for precise control of slurrying and reduction leaching conditions, further improving nickel and cobalt leaching rates while achieving controlled manganese leaching. The manganese leaching rate can be controlled within a range of 35% to 99%, paving the way for future market demands for varying nickel, cobalt, and manganese ratios.

[0062] In step (3) of the present invention, based on the high-manganese-containing slag obtained by the slurrying and reduction, an acidification leaching process is used to obtain manganese silicon slag that can be directly sold as a product, as well as a nickel-containing pickling solution. The nickel-containing pickling solution can be returned for further utilization, and the nickel can also be further recovered.

[0063] In some preferred embodiments, the acid leaching conditions are: a liquid-to-solid ratio of 4 to 6:1, a temperature of 70 to 90°C, a pH adjusted to 0.8 to 1.5, and a reaction time of 3 to 5 hours. Using the above acid leaching conditions can further improve the leaching rate of manganese silicon.

[0064] Steps (4) to (6) of the present invention are based on the preliminarily purified and easily filterable nickel-cobalt-manganese impurity solution obtained in step (2). A process combining aging leaching with secondary precipitation (one-stage iron and aluminum removal - aging leaching - two-stage iron and aluminum removal) is adopted to selectively precipitate iron and aluminum ions to obtain scandium-containing iron and aluminum slag. By further precipitating nickel, reusable high-nickel-containing alkaline substances are obtained, thereby achieving solid waste reduction and high value conversion.

[0065] In some preferred embodiments, in step 4, a first neutralizing agent is added to the preliminarily purified nickel-cobalt-manganese solution to adjust the pH to 4.5-5.2. The first neutralizing agent is a nickel-cobalt hydroxide raw material, or a nickel-containing alkaline substance obtained by reacting the nickel-cobalt hydroxide raw material with nickel precipitation, thereby preventing the introduction of impurity ions.

[0066] In addition, the inventors of the present application noticed that the nickel-cobalt hydroxide raw material is not easy to dissolve when the pH is above 2, and (when nickel-cobalt hydroxide is used alone as the first neutralizing agent) a large amount of raw material is required for pH adjustment, and it will enter the iron-aluminum slag, increasing the nickel-cobalt loss rate; while the high-nickel-containing alkaline substance obtained by the nickel precipitation reaction of the present invention is easy to adjust the pH, but its amount is small.

[0067] Based on this, it is preferred to use the nickel-cobalt hydroxide raw material and the nickel-precipitation reaction to obtain the nickel-containing alkaline substance as the first neutralizing agent. According to the design and calculation, the nickel-cobalt hydroxide raw material is first used to adjust the pH to a value (the pH range can be 1-2), and then the entire high-nickel-containing alkaline substance obtained after the back-end nickel precipitation reaction is used to adjust the pH to the desired value. By utilizing the alkaline properties of the nickel-cobalt hydroxide in MHP and the NiCO3 generated in the subsequent process to adjust the pH in sequence, the selective precipitation of iron and aluminum ions is achieved, effectively suppressing the introduction of calcium and magnesium ions, saving costs and reducing the loss rate of nickel and cobalt.

[0068] Furthermore, when adding an oxidant, the reaction temperature is 60-90°C, the stirring speed is 300-800 r / min, and the reaction time is 3-5 hours to further improve the reaction efficiency of the primary precipitation. The oxidant is air or H2O2. Furthermore, the amount of the oxidant is controlled during the reaction, with an air flow rate of 50-200 mL / min and an H2O2 dosage of 1.4 kg / t. 液量 .

[0069] In some preferred embodiments, in step 5), the filter cake obtained after the first-stage iron and aluminum removal is mixed with concentrated sulfuric acid for mature leaching. The mature leaching process includes an acid-to-ore ratio of 500-900 kg / t, stirring for 1-3 hours, followed by water addition to a liquid-to-solid ratio of 3-10:1. The temperature is 80-95°C, and the stirring speed is 300-800 rpm. By adding concentrated sulfuric acid and performing mature leaching on the filter cake obtained after the first-stage iron and aluminum removal under the above conditions, nickel and cobalt can be further recovered from the filter cake obtained in step 4), thereby improving overall leaching efficiency. Solid-liquid separation is then performed to obtain a desiliconized filtrate and matured leaching residue. Removing silicon from the desiliconized filtrate reduces the impact of silica gel production on subsequent processes (such as nickel and cobalt precipitation and filtration speed).

[0070] The mature leaching process involves a vigorous leaching of the material with concentrated acid (without the addition of water). This leaching changes the silicon morphology, converting the difficult-to-filter silica gel into easily filterable silica. By returning the mature leaching residue after mature leaching to the pulping and leaching stage—that is, returning the mature leaching residue containing easily filterable silica to the leaching stage—the filtration of the leachate can be further improved. Furthermore, the silicon is added to the slag during the leaching stage, and after processing, it forms a manganese silicon slag that can be sold externally.

[0071] In some preferred embodiments, in step 6, a second neutralizing agent is added to the desiliconization filtrate to adjust the pH to 3.5-4.0, and the reaction time is 3-5 hours at a temperature of 40-70°C. Under the above conditions, the secondary iron and aluminum removal is performed, further improving the reaction efficiency of the secondary precipitation, thereby obtaining scandium-containing iron and aluminum slag and nickel-containing impurity-removed filtrate.

[0072] The second neutralizing agent may be a nickel cobalt hydroxide raw material, may be Na2CO3, or may be a nickel cobalt hydroxide raw material and Na2CO3.

[0073] The inventors of this application have discovered that adding sodium carbonate alone as a second neutralizing agent can reduce the nickel and cobalt content in the ferroaluminum slag and reduce the nickel and cobalt loss rate. However, the amount of sodium carbonate used increases, increasing costs. Adding nickel and cobalt hydroxide alone, using the raw material as the second neutralizing agent, can save costs. However, the nickel and cobalt hydroxide raw material is difficult to dissolve at a pH of 2 or above, requiring a large amount of nickel and cobalt hydroxide for pH adjustment. Furthermore, the raw material will enter the ferroaluminum slag, increasing the nickel and cobalt loss rate.

[0074] Based on this, preferably, nickel cobalt hydroxide can be added first to appropriately adjust the pH, and then sodium carbonate is added to adjust to the required pH, which saves sodium carbonate and saves costs. Specifically, it can be calculated according to the design, first using nickel cobalt hydroxide raw material to adjust the pH to a value, such as adjusting the pH to within the range of 1-2, and then sodium carbonate is used to adjust to the required pH. The two are adjusted in sequence, not only to achieve selective precipitation of iron and aluminum ions, effectively suppressing the introduction of calcium and magnesium ions, but also to save costs and reduce nickel and cobalt loss rate.

[0075] In some preferred embodiments, a third neutralizing agent, Na2CO3, is added to the nickel-containing impurity-removed filtrate obtained by solid-liquid separation after secondary precipitation to adjust the pH to 7-8, and a nickel precipitation reaction is carried out. The reaction time is 2-4 hours, and the reaction temperature is 40-70°C. After the reaction, solid-liquid separation is performed to obtain a filter residue with a high nickel content, an alkaline substance NiCO3, and a filtrate, Na2SO4. As described above, all the filter residue NiCO3 can be reused, and the filtrate Na2SO4 can be evaporated and crystallized to obtain a by-product, thenardite. By using processes such as slag acid aging-secondary precipitation, scandium-iron-aluminum slag, recyclable high nickel content alkaline substances, and high-purity thenardite as a by-product are obtained, thereby achieving solid waste reduction and high value conversion.

[0076] In step (7) of the present invention, the neutralized liquid obtained by solid-liquid separation after the first stage of iron and aluminum removal is deeply purified and impurities are removed, and the impurities calcium, magnesium, silicon, copper and zinc therein are removed, thereby obtaining a purified nickel-cobalt-manganese solution and a purified nickel-cobalt-manganese liquid.

[0077] In some preferred embodiments, the neutralized solution is treated sequentially using manganese fluoride to remove calcium and magnesium, manganese and iron powders to remove copper, nickel sulfide to remove zinc, and polyferric sulfate to remove silicon. Multi-scale interface manipulation enables precise, targeted removal of impurity ions, surpassing the limits of traditional purification processes for trace impurity removal. This reduces the concentration of key impurities in the purified nickel-cobalt-manganese solution to less than 50 ppm, enabling direct use in ternary precursor preparation.

[0078] Specifically, the following steps may be included:

[0079] Manganese fluoride for removing calcium and magnesium: Mix the filtrate with MnF and stir for 0.5 to 1 h. The reaction temperature is 60 to 80 °C and the MnF dosage coefficient is 1 to 3 mol / mol. After the reaction, the solid and liquid are separated to obtain a calcium and magnesium removal filtrate and calcium and magnesium slag.

[0080] Desiliconization with polyferric sulfate: Mix the calcium and magnesium removal filtrate with polyferric sulfate (PFS) and stir for 0.5-2 hours at a reaction temperature of 40-60°C. The polyferric sulfate dosage ratio (PFS / SiO2) is 80-120 wt% / wt.%. Solid-liquid separation is then performed to produce silicon slag and desiliconized filtrate. The pH decreases after the addition of polyferric sulfate and must be adjusted to 4.5-5.0 within 8 minutes and maintained constant. The pH adjustment agent is a 90-98 wt.% NaOH solution. Polyferric sulfate flocculation offers more efficient silicon removal, reduces the silicon content in the solution, is easy to operate, and does not introduce new impurities into the system. Polyferric sulfate hydrolysis in water forms a polynuclear complex with charge neutralization. The positively charged groups can adsorb negatively charged colloidal silica (such as silica colloids). Bridging flocculation also forms coarse flocs, which encapsulate and precipitate silicon particles for removal. The high molecular flocculation properties and strong electrical neutralization ability of polyferric sulfate can be used to synergistically remove other pollutants, such as Pb in water. 2+ 、Cu 2+ Heavy metal ions, organic matter such as COD, phosphorus, etc. Compared with traditional iron salts or aluminum salts, the high molecular structure of polyferric sulfate makes it more efficient in adsorbing silicon, and the silicon removal rate can be increased by 10% to 30%.

[0081] Manganese powder and iron powder copper removal: the desiliconization filtrate is pumped into the copper removal tank, heated to 40-60 ° C, the Mn powder dosage coefficient is 1-2 mol / mol, the reaction is 1-3 hours, and the solid-liquid separation is carried out after the reaction to obtain copper slag and copper removal filtrate.

[0082] Nickel sulfide zinc removal: the copper removal filtrate is pumped into the zinc removal tank, heated to 40-50°C, sulfuric acid is added to adjust the pH to 4-6, the reaction time is 1-2 hours, the nickel sulfide dosage coefficient is 1-1.2 mol / mol, and then solid-liquid separation is carried out to obtain zinc slag and nickel-cobalt-manganese purified liquid.

[0083] The technical solution of the present invention is further described below with reference to specific embodiments and accompanying drawings: Example 1

[0084] High temperature pretreatment: Use high temperature steam to dry the nickel cobalt hydroxide raw materials.

[0085] Slurrying + leaching: The dried nickel cobalt hydroxide raw material is slurried, first adding water, the liquid-solid ratio is 3:1, the temperature is 80℃, concentrated sulfuric acid is added to adjust the pH to 4.8, and the reaction time is 3h; after slurrying, reduction leaching is carried out, the liquid-solid ratio is 5:1, the temperature is 80℃, concentrated sulfuric acid is added to adjust the pH to 1.5, the reducing agent is H2O2, the dosage / Mn content of the ore is 0.2 mol / mol, and filtration is performed to obtain a preliminarily purified nickel cobalt manganese solution and a high manganese-containing slag.

[0086] The high-manganese slag is acidified and leached at a liquid-to-solid ratio of 5:1, a temperature of 90°C, a pH of 1, a reaction time of 3 hours, and filtration to obtain manganese silicon slag and a nickel-containing pickling solution. The nickel-containing pickling solution can be returned to the slurrying + leaching step.

[0087] One-stage iron and aluminum removal: add the first neutralizing agent nickel cobalt hydroxide raw material to the preliminarily purified nickel cobalt manganese solution to adjust the pH to 4.5 (alternatively, first add the neutralizing agent nickel cobalt hydroxide raw material to adjust the pH to a certain value, and then use NiCO3 obtained in a subsequent process to adjust the pH to 4.5), the oxidant is air, the reaction is carried out for 4 hours, and after solid-liquid separation, a filtrate and filter residue (i.e., filter cake) are obtained.

[0088] Mature leaching: Mix the filter residue with concentrated sulfuric acid at an acid-ore ratio of 800 kg / t, stir for 3 hours, then add water to a liquid-solid ratio of 6:1. The test temperature is 90°C and the stirring speed is 500 r / min. Solid-liquid separation is performed to obtain mature leaching residue and desiliconized filtrate, and the mature leaching residue is returned to the slurrying + leaching stage.

[0089] Second-stage iron and aluminum removal: add the second neutralizing agent nickel cobalt hydroxide raw material to the desiliconization filtrate to adjust the pH to 3.5 (or first add the neutralizing agent nickel cobalt hydroxide raw material to adjust the pH to a value, and then add Na2CO3 to adjust the pH to 3.5), the reaction time is 4h, the reaction temperature is 70℃, and then solid-liquid separation is carried out to obtain iron and aluminum slag and impurity-removed filtrate.

[0090] Nickel precipitation: Add the third neutralizing agent, Na2CO3, to the impurity removal filtrate to adjust the pH to 8. The reaction is carried out for 3 hours at 60°C. After nickel precipitation, solid-liquid separation is performed to obtain filter residue NiCO3 and filtrate Na2SO4. The filter residue NiCO3 can be reused for the first stage of iron and aluminum removal. The filtrate Na2SO4 is evaporated and crystallized to obtain the by-product, Glauber's salt.

[0091] Impurity removal: add MnF with a dosage coefficient of 2 mol / mol to the filtrate obtained by neutralizing and removing iron and aluminum, i.e., the first step of removing iron and aluminum, stir for 1 hour, and the reaction temperature is 70°C, and then separate the solid and liquid to obtain a calcium and magnesium removal filtrate and a calcium and magnesium slag; add polyferric sulfate with a dosage coefficient of PFS / SiO2 of 80wt% / wt.% to the calcium and magnesium removal filtrate, stir for 0.5 hour, and the reaction temperature is 50°C to obtain silicon slag and desiliconization filtrate; add Mn powder with a dosage coefficient of 1.5 mol / mol to the desiliconization filtrate, heat to 50°C, stir for 1 hour, and separate the solid and liquid to obtain copper slag and decoppering filtrate; adjust the pH of the decoppering filtrate to 5, and then add nickel sulfide with a dosage coefficient of 1 mol / mol, heat to 45°C, stir for 1 hour, and separate the solid and liquid to obtain zinc slag and a purified nickel-cobalt-manganese solution;

[0092] The test results are as follows:

[0093] The nickel-cobalt leaching rate is 98%, the manganese leaching rate is 45%, the nickel content of the iron-aluminum slag is 0.5%, and the silicon removal rate is 95%. The purified nickel-cobalt-manganese solution has residual calcium and magnesium contents of 30ppm, residual copper and zinc contents of 0.8ppm, and a silicon content of 30ppm.

[0094] The description of the present invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the form disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles of the invention and its practical application and to enable those skilled in the art to understand the invention and design various embodiments with various modifications as are suited for specific applications.

Claims

1. A MHP short-process process for preparing nickel-cobalt-manganese purified liquid, characterized in that: include: High-temperature steam is used to dry the nickel-cobalt hydroxide raw materials; The dried nickel-cobalt hydroxide raw material is slurried by staged acid control, and reduction leaching is performed after slurrying. The amount of reducing agent added is controlled, the leaching rate of manganese is controlled, and solid-liquid separation is performed to obtain a preliminarily purified nickel-cobalt-manganese solution and manganese-containing slag. The end point pH is first adjusted to 4.0-5.5 in the slurrying stage, and the end point pH is further adjusted to 1-2 in the reduction leaching stage. Acid leaching is performed on the manganese-containing slag at a liquid-solid ratio of 4 to 6:1, a temperature of 70 to 90° C., a pH value of 0.8 to 1.5, a reaction time of 3 to 5 hours, and solid-liquid separation to obtain manganese silicon slag that can be sold and a nickel-containing pickling solution; adding a first neutralizing agent to the preliminarily purified nickel-cobalt-manganese solution to adjust the pH, adding an oxidizing agent, performing a first iron and aluminum removal reaction, and performing solid-liquid separation to obtain a filtrate and a filter residue; Adding concentrated sulfuric acid to the filter residue for ripening and leaching, and separating the solid and liquid to obtain ripened leaching residue and desiliconized filtrate; returning the ripened leaching residue to the reduction leaching stage; A second neutralizing agent is added to the desiliconization filtrate to adjust the pH, perform a two-stage iron and aluminum removal reaction, and perform solid-liquid separation to obtain a scandium-containing iron and aluminum slag and a nickel-containing impurity-removed filtrate; a third neutralizing agent is added to the nickel-containing impurity-removed filtrate to adjust the pH, perform a nickel precipitation reaction, and perform solid-liquid separation to obtain a nickel-containing alkaline substance; Calcium, magnesium, silicon, copper and zinc impurities in the filtrate are removed in sequence to obtain a nickel-cobalt-manganese purified liquid, wherein manganese fluoride is used to remove calcium and magnesium, polyferric sulfate is used to remove silicon, manganese powder or iron powder is used to remove copper, and nickel sulfide is used to remove zinc.

2. The MHP short-process process for preparing nickel-cobalt-manganese purified liquid according to claim 1, characterized in that: When high-temperature steam is used to dry the nickel cobalt hydroxide raw material, it is dried until the moisture content is less than 10%.

3. The MHP short-process process for preparing nickel-cobalt-manganese purified liquid according to claim 1, characterized in that: The dried nickel cobalt hydroxide raw material is slurried and then subjected to reduction leaching. The reducing agent is one of H2O2, SO2, and Na2SO3; the reducing agent dosage is controlled as follows: reducing agent dosage / Mn content of the ore is 0.2-1 mol / mol; Slurry preparation process: reaction temperature is 60-90°C, stirring speed is 300-800r / min, and reaction time is 2-4h; Reduction leaching process: reaction temperature is 60-90°C, stirring speed is 300-800r / min, and reaction time is 1.5-3h.

4. The MHP short-process process for preparing nickel-cobalt-manganese purified liquid according to claim 1, characterized in that: Also includes: The nickel-containing pickling solution is returned to the reduction leaching stage.

5. The MHP short-process process for preparing nickel-cobalt-manganese purified liquid according to claim 1, characterized in that: Add the first neutralizer to adjust the pH to 4.5-5.2; when adding the oxidant to react, the temperature is 60-90°C, the stirring speed is 300-800 r / min, and the reaction time is 3-5 hours; The first neutralizing agent is a nickel-cobalt hydroxide raw material, or a nickel-containing alkaline substance obtained by reacting the nickel-cobalt hydroxide raw material with nickel precipitation; the oxidizing agent is air or H2O2.

6. The MHP short-process process for preparing nickel-cobalt-manganese purified liquid according to claim 1, characterized in that: Mature leaching process: acid-ore ratio is 500-900 kg / t, stirring for 1-3 hours, then adding water to the liquid-solid ratio of 3-10:1, temperature is 80-95℃, stirring speed is 300-800 r / min; A second neutralizing agent is added to adjust the pH to 3.5-4.0, the reaction time is 3-5 hours, and the reaction temperature is 40-70° C.; the second neutralizing agent is a nickel cobalt hydroxide raw material and / or Na2CO3.

7. The MHP short-process process for preparing nickel-cobalt-manganese purified liquid according to claim 6, characterized in that: The third neutralizing agent is Na2CO3; the third neutralizing agent is added to adjust the pH to 7-8 for nickel precipitation reaction, the reaction temperature is 40-70 ° C, the reaction time is 2-4h, and a Na2SO4 solution and a nickel-containing alkaline substance NiCO3 are obtained; The Na2SO4 solution is subjected to evaporation and crystallization treatment to obtain a by-product, Glauber's salt.

8. The MHP short-process process for preparing nickel-cobalt-manganese purified liquid according to claim 1, characterized in that: Sequentially removing calcium, magnesium, silicon, copper, and zinc impurities from the filtrate comprises the following steps: Calcium and magnesium removal: Mix the filtrate with MnF and stir for 0.5 to 1 hour. The reaction temperature is 60 to 80°C and the MnF dosage coefficient is 1 to 3 mol / mol. After the reaction, the solid and liquid are separated to obtain a calcium and magnesium removal filtrate and calcium and magnesium slag. Desiliconization: Mix the calcium and magnesium removal filtrate with polyferric sulfate, stir for 0.5 to 2 hours, the reaction temperature is 40 to 60 ° C, the polyferric sulfate dosage coefficient PFS / SiO2 is 80 to 120 wt% / wt.%, and then separate the solid and liquid to obtain silicon slag and desiliconization filtrate; Copper removal: the desiliconization filtrate is pumped into a copper removal tank, heated to 40-60°C, the manganese powder dosage coefficient is 1-2 mol / mol, and the reaction is carried out for 1-3 hours. After the reaction, the solid and liquid are separated to obtain copper slag and copper removal filtrate; Zinc removal: The copper removal filtrate is pumped into a zinc removal tank, heated to 40-50°C, sulfuric acid is added to adjust the pH to 4-6, the reaction time is 1-2 hours, the nickel sulfide dosage coefficient is 1-1.2 mol / mol, and then solid-liquid separation is performed to obtain zinc slag and nickel-cobalt-manganese purified liquid.

9. The MHP short-process process for preparing nickel-cobalt-manganese purified liquid according to claim 8, characterized in that: The nickel and cobalt leaching rate is ≥98%, and the manganese leaching rate can be controlled within the range of 35% to 99%; The concentration of key impurities in the nickel-cobalt-manganese purified solution is lower than 50 ppm; the key impurities include calcium, magnesium, copper, zinc and silicon.

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