Precipitation method for heavy metal solution
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-07-07
- Publication Date
- 2026-08-13
Smart Images
Figure CN2025107304_13082026_PF_FP_ABST
Abstract
Description
Precipitation methods for heavy metal solutions
[0001] This disclosure claims priority to Chinese Patent Application No. 202510145092.0, filed on February 10, 2025, entitled "Precipitation Method of Heavy Metal Solution", the entire contents of which are incorporated herein by reference. Technical Field
[0002] This disclosure relates to the field of heavy metal hydrometallurgy technology, and more specifically, to a method for precipitation of heavy metal solutions. Background Technology
[0003] Precipitation enrichment methods are used in various fields of hydrometallurgy, such as the precipitation enrichment of nickel and cobalt in laterite nickel ore hydrometallurgy, and the precipitation enrichment of nickel, cobalt, and copper after leaching for battery material recovery. These processes require the use of precipitants, and common precipitants are various alkalis. However, these alkalis introduce sodium ions into the system, and the products after direct precipitation have poor sedimentation and filtration performance, high water content, and serious environmental pollution. They are difficult to implement in engineering and bring great difficulties to production.
[0004] Existing nickel-cobalt precipitation processes often employ sodium hydroxide or sulfide precipitation methods, for example:
[0005] Patent CN101575676A discloses a method for iron precipitation and nickel-cobalt enrichment. In the nickel-cobalt enrichment step, a sulfiding agent is used for sulfidation precipitation. This patent uses one or more of the following sulfiding agents for nickel-cobalt precipitation: hydrogen sulfide, persulfide, sodium hydrosulfide, sodium sulfide, potassium sulfide, ammonium sulfide, magnesium sulfide, and zinc sulfide. Hydrogen sulfide exhibits the best precipitation effect, but it is highly toxic, requiring sophisticated operation and system specifications, and the intermediate products from sulfidation precipitation are difficult to process.
[0006] Patent CN102061387A discloses a two-stage nickel precipitation method. NaOH solution is added to a magnesium-containing nickel sulfate solution to adjust the pH to 7.5–8.5, the reaction temperature is 20–80℃, and the reaction time is 0.5–3 hours. The resulting precipitate is separated from the mother liquor. The precipitate proceeds to the next step, where NaOH solution is added to the mother liquor to adjust the pH to 9–10, the reaction temperature is 20℃–80℃, and the reaction time is 0.5–3 hours. Finally, the resulting precipitate is separated from the mother liquor and returned to the stirred leaching system for circulation. This patent directly uses sodium hydroxide or a mixed alkaline solution to precipitate nickel and cobalt, introducing new sodium ions into the system. The resulting product is fine, difficult to settle, and has a high water content.
[0007] In summary, the hydrogen sulfide precipitation process for nickel and cobalt is widely used due to its advantages, including high precipitation rate, low precipitation pH, and the ability to recover nickel and cobalt even under acidic leachate conditions without further purification. However, hydrogen sulfide is highly toxic, posing significant safety and environmental risks, and the subsequent processing of the intermediate products obtained from precipitation is extremely complex. The sodium hydroxide precipitation process for nickel and cobalt is simpler and requires less equipment investment. However, the inventors realized that directly using strongly alkaline sodium hydroxide as a precipitant would result in small particle size of the nickel-cobalt hydroxide (MHP) precipitate, introduce new sodium ion impurities, poor settling ability, hindering liquid-solid separation, and causing high moisture content in the filter cake, which would complicate subsequent transportation and processing.
[0008] In view of this, this disclosure is hereby made. Summary of the Invention
[0009] In view of the above problems, the purpose of this disclosure is to provide a precipitation method for heavy metal solutions, so as to solve the problems of poor sedimentation and filtration performance of precipitated products, high water content of precipitated products, and low precipitation efficiency in the prior art when precipitating heavy metals from heavy metal solutions.
[0010] To achieve the above objectives, according to one aspect of this disclosure, a method for precipitation of heavy metal solutions is provided, wherein the cations in the heavy metal solutions include nickel ions, cobalt ions, copper ions, zinc ions, and manganese ions. The precipitation method includes: step S100, using a manganese-containing solution to perform a manganese conversion reaction on an alkaline substance to obtain converted manganese precipitate; step S200, using a stabilizer to stabilize the converted manganese precipitate to obtain a stabilized manganese precipitate; step S300, adding the stabilized manganese precipitate to the heavy metal solution for a precipitation reaction to obtain a precipitate slurry; step S400, continuously performing solid-liquid separation on the precipitate slurry to obtain a heavy metal precipitate and a manganese-containing solution; and step S500, performing an oxidative precipitation reaction on raw materials including the manganese-containing solution, an oxidant, and an alkaline solution to obtain a precipitated liquid and a manganese product.
[0011] One optional technical solution is that, in step S100 above, the mass concentration of manganese ions in the manganese ion-containing solution is 1 g / L to 300 g / L, preferably 1 g / L to 80 g / L, more preferably 1 g / L to 30 g / L, and even more preferably 10 g / L to 20 g / L.
[0012] One optional technical solution is that, in step S100 above, the heavy metal solution is selected from any one of the following: the iron and aluminum removal solution of laterite nickel ore acid leaching solution, the battery material black powder leaching solution in the field of lithium battery recycling, and the copper-cobalt solution in copper-cobalt hydrometallurgical process.
[0013] One optional technical solution is that, in step S100 above, the alkaline substance is selected from any one or more of hydroxides, alkaline earth metal oxides, carbonates, and bicarbonates. Specifically, the hydroxide is selected from any one or more of sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, ammonium hydroxide, and lithium hydroxide; the alkaline earth metal oxide is selected from any one or more of magnesium oxide and calcium oxide; the carbonate is selected from any one or more of magnesium carbonate, calcium carbonate, potassium carbonate, sodium carbonate, and ammonium carbonate; and the bicarbonate is selected from any one or more of magnesium bicarbonate, calcium bicarbonate, potassium bicarbonate, sodium bicarbonate, and ammonium bicarbonate. Further, it is preferred that the alkaline substance is a combination of sodium hydroxide and potassium hydroxide, and the preferred mass ratio of sodium hydroxide to potassium hydroxide is 1–4:1–4.
[0014] One optional technical solution is that, in step S100 above, based on the stoichiometric molar ratio of the alkaline substance to the manganese ion to form a manganese precipitate, the alkaline substance is added at 0.1 to 3 times, preferably at 0.8 to 1.5 times, and even more preferably at 0.8 to 0.9 times.
[0015] One optional technical solution is that, in step S100 above, the temperature of the manganese conversion reaction is 25℃~100℃, preferably 60℃~100℃, and the time of the manganese conversion reaction is 0.1min~30min, preferably 1min~5min.
[0016] One optional technical solution is that, in step S100 above, the manganese ion-containing solution is derived from any one of the following: a manganese-containing solution, the liquid phase after leaching from a ternary battery, and the liquid phase of the slurry after a stage of nickel-cobalt precipitation.
[0017] One optional technical solution is that, in step S200 above, the temperature of the stabilization reaction is 25℃~100℃, preferably 60℃~100℃, and the time of the stabilization reaction is 0.1min~180min, preferably 30min~60min.
[0018] One optional technical solution is that, in step S200 above, the mass of the stabilizer is 0.1% to 30% of the mass of the converted manganese precipitate, preferably 1% to 5%.
[0019] One optional technical solution is that, in step S200 above, the stabilizer is selected from any one or more of glucose, sulfur dioxide, sulfite, L-ascorbic acid, alcohol and aldehyde; preferably, the sulfite is sodium sulfite and / or potassium sulfite, and more preferably, sodium sulfite.
[0020] One optional technical solution is that, in step S300 above, the ratio of the total molar amount of heavy metal ions in the heavy metal solution to the molar amount of manganese ions in the stable manganese precipitate is 1:0.1 to 5, preferably 1:0.8 to 1.
[0021] One optional technical solution is that, in step S300 above, the temperature of the precipitation reaction is 25℃~100℃, preferably 60℃~100℃, and the precipitation reaction time is 0.1min~600min, preferably 60min~180min.
[0022] One optional technical solution is that, in step S500 above, the oxidant is selected from any one or more of air, oxygen, oxygen-enriched gas, ozone, hydrogen peroxide, persulfate, hypochlorite, and perchlorate.
[0023] One optional technical solution is that, in step S500 above, the amount of oxidant used is 0.5 to 5 times the molar amount of manganese ions in the manganese-containing solution, preferably 1 to 1.5 times.
[0024] One optional technical solution is that, in step S500 above, the amount of alkali solution used is 0.5 to 5 times the molar amount of manganese ions in the manganese-containing solution, preferably 1 to 2 times, and the alkali solution is selected from any one or more of ammonia, potassium hydroxide, sodium hydroxide and calcium hydroxide.
[0025] This disclosure proposes a method of converting and stabilizing an alkaline substance (i.e., a precipitant) with manganese to generate a stable manganese precipitate, namely manganese hydroxide or oxide. This stable manganese precipitate is then used to precipitate a heavy metal solution. This process not only achieves heavy metal enrichment but also ensures the structural stability and reaction efficiency of the heavy metal precipitate through the manganese conversion and stabilization reactions, avoiding sodium ion pollution and treatment difficulties associated with traditional precipitants (such as alkali metals). Furthermore, the obtained heavy metal precipitate product has low water content, significantly improved sedimentation and filtration performance, and the manganese in the precipitated solution can be recovered through an oxidation precipitation reaction, solving the system pollution problem. In addition, thanks to the combined manganese conversion and stabilization steps, the stable manganese precipitate obtained in this disclosure exhibits excellent chemical properties in the precipitation reaction of step S300, thereby improving not only the recovery rate and product quality of heavy metal ions but also the precipitation efficiency of heavy metals such as nickel and cobalt, achieving efficient resource recycling. This disclosure solves the problems of poor sedimentation and filtration performance, high water content, and low precipitation efficiency of precipitates in existing technologies for precipitating heavy metals from heavy metal solutions.
[0026] To achieve the foregoing and related objectives, one or more aspects of this disclosure include features that will be described in detail below and specifically pointed out in the claims. The following description and accompanying drawings illustrate certain exemplary aspects of this disclosure. However, these aspects indicate only a few of the various ways in which the principles of this disclosure can be applied. Furthermore, this disclosure is intended to include all such aspects and their equivalents. Attached Figure Description
[0027] Other objects and results of this disclosure will become more apparent and readily understood upon reference to the following description taken in conjunction with the accompanying drawings and the claims, and with a more complete understanding of this disclosure. The accompanying drawings, which form part of this disclosure, are used to provide a further understanding of this disclosure. The illustrative embodiments of this disclosure and their descriptions are used to explain this disclosure and do not constitute an undue limitation of this disclosure. In the drawings:
[0028] Figure 1 shows a flowchart of a precipitation method for a heavy metal solution according to an embodiment of the present disclosure.
[0029] In all the accompanying drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed Implementation
[0030] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that the embodiments and features described herein can be combined with each other without conflict; these embodiments can also be implemented without these specific details. In other instances, well-known structures and devices are shown in block diagram form for ease of description of one or more embodiments.
[0031] The specific embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.
[0032] As described in the background section, existing technologies for precipitating heavy metals from heavy metal solutions suffer from problems such as poor sedimentation and filtration performance of the precipitated products, high water content of the precipitated products, and low precipitation efficiency. To solve these technical problems, this disclosure provides a method for precipitating heavy metal solutions.
[0033] To address the aforementioned problems, this disclosure provides a method for precipitation of heavy metal solutions, wherein the cations in the heavy metal solution include nickel ions, cobalt ions, copper ions, zinc ions, and manganese ions. The precipitation method includes: step S100, using a manganese-containing solution to perform a manganese conversion reaction on an alkaline substance to obtain converted manganese precipitate; step S200, using a stabilizer to stabilize the converted manganese precipitate to obtain a stabilized manganese precipitate; step S300, adding the stabilized manganese precipitate to the heavy metal solution for a precipitation reaction to obtain a precipitate slurry; step S400, continuously performing solid-liquid separation on the precipitate slurry to obtain a heavy metal precipitate and a manganese-containing solution; and step S500, performing an oxidative precipitation reaction on raw materials including the manganese-containing solution, an oxidant, and an alkaline solution to obtain a precipitated liquid and a manganese product.
[0034] This disclosure proposes a method of converting and stabilizing an alkaline substance (i.e., a precipitant) with manganese to generate a stable manganese precipitate, namely manganese hydroxide or oxide. This stable manganese precipitate is then used to precipitate a heavy metal solution. This process not only achieves heavy metal enrichment but also ensures the structural stability and reaction efficiency of the heavy metal precipitate through the manganese conversion and stabilization reactions, avoiding sodium ion pollution and treatment difficulties associated with traditional precipitants (such as alkali metals). Furthermore, the obtained heavy metal precipitate product has low water content, significantly improved sedimentation and filtration performance, and the manganese in the precipitated solution can be recovered through an oxidation precipitation reaction, solving the system pollution problem. In addition, thanks to the combined manganese conversion and stabilization steps, the stable manganese precipitate obtained in this disclosure exhibits excellent chemical properties in the precipitation reaction of step S300, thereby improving not only the recovery rate and product quality of heavy metal ions but also the precipitation efficiency of heavy metals such as nickel and cobalt, achieving efficient resource recycling. This solves the problems of poor sedimentation and filtration performance, high water content, and low precipitation efficiency of precipitates in existing technologies for heavy metal precipitation from heavy metal solutions.
[0035] In a preferred embodiment, in order to maintain better precipitation activity of the stabilized manganese precipitate and prevent it from being oxidized after being left for a long time, the stabilized manganese precipitate is returned to the aforementioned step S300 to participate in the precipitation reaction within 5 minutes, more preferably within 3 minutes.
[0036] In one embodiment of this disclosure, in step S100 above, the mass concentration of manganese ions in the manganese ion-containing solution is 1 g / L to 300 g / L, preferably 1 g / L to 80 g / L, more preferably 1 g / L to 30 g / L, and even more preferably 10 g / L to 20 g / L.
[0037] The selection of a manganese ion concentration within the above range in the manganese-containing solution is based on the stability and reaction efficiency of manganese ions in solution. This ensures the smooth progress of the manganese conversion reaction while avoiding interference from excessive manganese ions in subsequent precipitation reactions, thus preventing resource waste and reducing production costs. The manganese ion concentration in the solution can be 1 g / L, 2 g / L, 3 g / L, 5 g / L, 10 g / L, 20 g / L, 30 g / L, 50 g / L, 60 g / L, 80 g / L, 100 g / L, 120 g / L, 150 g / L, 180 g / L, 200 g / L, 220 g / L, 250 g / L, 280 g / L, or 300 g / L, and is not limited to any single value within the range of 1 g / L to 300 g / L.
[0038] This disclosed method can adapt to the treatment of various heavy metal-containing solutions, has wide applicability, increases its application potential in different industries, and improves the flexibility and efficiency of resource recycling. In some preferred embodiments of this disclosure, in step S100 above, the heavy metal solution is selected from any one of the following: the iron and aluminum removal solution from laterite nickel ore acid leaching, the battery material black powder leaching solution in the lithium battery recycling field, and the copper-cobalt solution in copper-cobalt hydrometallurgical processes. Of course, the above-mentioned heavy metal solution can also be other alloys, solutions containing the above-mentioned heavy metals after leaching of waste, or various types of heavy metal-containing wastewater, etc., and the metal types can be one or more. That is, the precipitation method of heavy metal solutions in this disclosure has a wide range of applications and is not limited to specific industrial fields.
[0039] In one embodiment of this disclosure, in step S100 above, the alkaline substance is selected from any one or more of hydroxides, alkaline earth metal oxides, carbonates, and bicarbonates. Specifically, the hydroxide is selected from any one or more of sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, ammonium hydroxide, and lithium hydroxide; the alkaline earth metal oxide is selected from any one or more of magnesium oxide and calcium oxide; the carbonate is selected from any one or more of magnesium carbonate, calcium carbonate, potassium carbonate, sodium carbonate, and ammonium carbonate; and the bicarbonate is selected from any one or more of magnesium bicarbonate, calcium bicarbonate, potassium bicarbonate, sodium bicarbonate, and ammonium bicarbonate.
[0040] Using the aforementioned alkaline substances makes the precipitation activity of the manganese conversion reaction more suitable, thereby enriching the types of manganese conversion precipitates. This, in turn, helps to improve the particle morphology of heavy metal precipitates, facilitates liquid-solid separation, and results in a final product with lower water content and lower manganese content. Furthermore, these alkaline substances are widely available, economical, efficient, and environmentally friendly. Using these specific alkaline substances as precipitants effectively avoids the introduction of impurity ions when using traditional precipitants, optimizes the purity and performance of the precipitate, reduces the difficulty of subsequent processing, and contributes to a cleaner production process. Further, a combination of sodium hydroxide and potassium hydroxide is preferred as the alkaline substance, with a preferred mass ratio of sodium hydroxide to potassium hydroxide of 1–4:1–4. For example, the mass ratio of sodium hydroxide to potassium hydroxide can be 1:1, 1:4, 1:2, or 4:1, but is not limited to any one of the mass ratios of 1–4:1–4.
[0041] To make the manganese conversion reaction more stable and the resulting stable manganese precipitate more stable, in a preferred embodiment, in step S100 above, based on the stoichiometric molar ratio of the alkaline substance to manganese ions to form manganese precipitate, the alkaline substance is added at a ratio of 0.1 to 3 times, preferably 0.8 to 1.5 times, and more preferably 0.8 to 0.9 times. Controlling the amount of alkaline substance added within the above range promotes a more stable manganese conversion reaction and results in a more suitable amount of stable manganese precipitate, thereby making the precipitation reaction more efficient and stable. The alkaline substance can be added at ratios of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 2, 2.3, 2.5, 2.8, or 3 times, and is not limited to any value within the range of 0.1 to 3 times.
[0042] Furthermore, the above range is set based on the theory of chemical equilibrium, aiming to achieve the best precipitation effect by precisely controlling the ratio of alkaline substances to manganese ions, while avoiding resource waste and system pollution caused by excessive alkaline substances. This setting not only improves the selectivity and efficiency of the precipitation reaction, but also reduces the precipitation of non-target metals through precise measurement, thereby improving the recovery rate and purity of the target metal.
[0043] Based on thermodynamic and kinetic principles, in some preferred embodiments of this disclosure, in step S100, the temperature of the manganese conversion reaction is 25℃~100℃, preferably 60℃~100℃, and the reaction time is 0.1min~30min, preferably 1min~5min. Controlling these conditions helps to ensure the efficient conduction of the manganese conversion reaction under mild conditions, thereby reducing the risk of side reactions and energy consumption that may be caused by high temperatures and long reaction times. By optimizing the above-mentioned manganese conversion reaction conditions, not only is the conversion rate and the quality of the manganese precipitate improved, but energy consumption is also reduced, which is conducive to achieving both economic and environmental benefits. The temperature of the manganese conversion reaction can be 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, or 100℃, and is not limited to any value within the range of 25℃~100℃. The time for the manganese conversion reaction can be 0.1 min, 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 8 min, 10 min, 12 min, 14 min, 16 min, 18 min, 20 min, 23 min, 25 min, 28 min or 30 min, but is not limited to any value between 0.1 min and 30 min.
[0044] In one embodiment of this disclosure, in step S100 above, the manganese ion-containing solution is derived from any one of the following: a manganese-containing solution, the liquid phase after leaching from a ternary battery, and the liquid phase of a nickel-cobalt slurry after a first stage of nickel precipitation.
[0045] The manganese-containing solution in step S100 has a wide range of sources. It is emphasized that the manganese-containing solution can be a manganese-containing byproduct from the lithium-ion battery recycling process, a manganese-containing byproduct from the nickel-cobalt precipitation process, or a manganese-containing solution generated during the heavy metal solution precipitation process of this disclosure. Therefore, the heavy metal solution precipitation method of this disclosure not only cleverly utilizes manganese ions in the manganese-containing byproducts to improve the recovery rate and product quality of heavy metal ions, but also improves the recycling of manganese-containing byproducts in the above processes. This not only reduces raw material consumption and production costs, but also reduces waste emissions, promotes green manufacturing and sustainable development, and increases overall economic value.
[0046] To improve the stability of the generated stable manganese precipitate, in some preferred embodiments of this disclosure, in step S200, the stabilization reaction temperature is 25℃~100℃, preferably 60℃~100℃, and the stabilization reaction time is 0.1min~180min, preferably 30min~60min. Controlling the stabilization reaction conditions facilitates the efficient stabilization process of the converted manganese precipitate and reduces the risk of forming unstable products. The stabilization reaction of the converted manganese precipitate increases the chemical stability of the precipitate, improves the selectivity and efficiency of subsequent precipitation reactions, and reduces energy consumption and by-products in the processing, thereby optimizing the entire production process. The stabilization reaction temperature can be 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, or 100℃, and is not limited to any value within the range of 25℃~100℃. The stabilization reaction time can be 0.1 min, 1 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 90 min, 100 min, 120 min, 130 min, 140 min, 150 min, 160 min, 170 min or 180 min, but is not limited to any value from 0.1 min to 180 min.
[0047] In addition, a stabilizer can be added during the above manganese conversion reaction, that is, the manganese conversion reaction and the stabilization reaction can be combined into one step, or the stabilizer can be added first and then the manganese conversion reaction can be carried out. The specific choice of one of the three schemes can be made according to the actual situation, which will not be elaborated here.
[0048] In one embodiment of this disclosure, in step S200 above, the mass of the stabilizer is 0.1% to 30% of the mass of the converted manganese precipitate, preferably 1% to 5%.
[0049] The above proportions aim to ensure the structural stability and reactivity of the manganese-converting precipitate through appropriate amounts of stabilizer, avoiding a decrease in reactivity due to over-stabilization. By optimizing the amount of stabilizer, not only is the stability and reactivity rate of the manganese-converting precipitate improved, but the additional costs and processing difficulties caused by excessive stabilizer are also reduced, contributing to a more economical production method. The mass of the stabilizer can be 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 8%, 10%, 12%, 15%, 18%, 20%, 25%, 28%, or 30% of the mass of the manganese-converting precipitate, and is not limited to any value between 0.1% and 30%.
[0050] To enhance the synergistic effect between the stabilizer and the manganese precipitate, resulting in a more stable manganese precipitate, in some preferred embodiments of this disclosure, the stabilizer in step S200 is selected from any one or more of glucose, sulfur dioxide, sulfites, L-ascorbic acid, alcohols, and aldehydes. These substances can effectively stabilize the manganese precipitate through redox reactions, complexation, or adsorption, reducing the risk of decomposition or loss of activity during subsequent processing. Furthermore, using these specific stabilizers not only improves the stability of the converted manganese precipitate but also broadens the range of stabilizer choices, reduces dependence on specific stabilizers, and increases process flexibility and cost control. In addition, sodium sulfite and / or potassium sulfite are preferred, and sodium sulfite is further preferred.
[0051] Based on chemical reaction theory, in some preferred embodiments of this disclosure, in step S300 above, the ratio of the total molar amount of heavy metal ions in the heavy metal solution to the molar amount of manganese ions in the stable manganese precipitate is 1:0.1 to 5, preferably 1:0.8 to 1. The above ratio is set to promote effective precipitation of heavy metals through an appropriate amount of stable manganese precipitate, avoiding problems caused by insufficient or excessive precipitant. By controlling the molar ratio of the precipitation reaction, not only is the selectivity and efficiency of the precipitation reaction improved, but energy consumption and by-product generation during the precipitation process are also reduced, which is beneficial to improving the heavy metal recovery rate and product quality, while also reducing production costs. The ratio of the total molar amount of heavy metal ions in the heavy metal solution to the molar amount of manganese ions in the stable manganese precipitate can be 1:0.1, 1:0.2, 1:0.5, 1:0.8, 1:0.9, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, or 1:5, and is not limited to any value from 1:0.1 to 5.
[0052] Based on thermodynamic and kinetic principles, in some preferred embodiments of this disclosure, in step S300, the precipitation reaction temperature is 25℃~100℃, preferably 60℃~100℃, and the precipitation reaction time is 0.1min~600min, preferably 60min~180min. These preferred conditions promote efficient precipitation reaction under mild conditions, reducing the potential for metal dissolution and energy waste caused by high temperatures and prolonged reactions. By optimizing the precipitation reaction conditions, not only is precipitation efficiency and metal recovery rate improved, but environmental pollution that may occur during the reaction is also reduced, contributing to a greener production process. The precipitation reaction temperature can be 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, or 100℃, and is not limited to any value within the range of 25℃~100℃. The precipitation reaction time can be 0.1 min, 1 min, 10 min, 20 min, 30 min, 50 min, 60 min, 70 min, 90 min, 100 min, 120 min, 130 min, 150 min, 200 min, 250 min, 300 min, 350 min, 400 min, 450 min, 500 min, 550 min, or 600 min, but is not limited to any value from 0.1 min to 600 min.
[0053] In some embodiments of this disclosure, in step S500 above, the oxidant is selected from any one or more of air, oxygen, oxygen-enriched gas, ozone, hydrogen peroxide, persulfate, hypochlorite, and perchlorate.
[0054] These oxidants convert manganese ions in manganese-containing solutions into a precipitable state through oxidation, thus enabling the recovery and utilization of manganese. Using these specific oxidants not only improves manganese recovery efficiency and reduces resource consumption, but also avoids the safety hazards that may arise from using strong oxidants, facilitating a safer and more environmentally friendly production process.
[0055] To ensure more complete oxidation of manganese ions in the manganese-containing solution, based on chemical reaction theory, in some preferred embodiments of this disclosure, the amount of oxidant used in step S500 is 0.5 to 5 times the molar amount of manganese ions in the manganese-containing solution, preferably 1 to 1.5 times. This ratio is set to ensure complete oxidation of manganese with an appropriate amount of oxidant, avoiding problems caused by insufficient or excessive oxidant. By controlling the amount of oxidant, not only is efficient recovery of manganese guaranteed, but also byproducts generated due to excessive oxidant are reduced, processing costs are lowered, and the safety and environmental friendliness of the production process are improved. The amount of oxidant can be 0.5, 0.8, 1, 1.2, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5 times the molar amount of manganese ions in the manganese-containing solution, and is not limited to any value from 0.5 to 5 times.
[0056] To ensure more complete precipitation of oxidized manganese ions in the manganese-containing solution, based on chemical reaction theory, in some preferred embodiments of this disclosure, in step S500, the amount of alkali solution used is 0.5 to 5 times, preferably 1 to 2 times, the molar amount of manganese ions in the manganese-containing solution, and the alkali solution is selected from any one or more of ammonia, potassium hydroxide, sodium hydroxide, and calcium hydroxide.
[0057] The amount of alkali solution used can be 0.5, 0.8, 1, 1.2, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5 times the molar amount of manganese ions in the manganese-containing solution, and is not limited to any value between 0.5 and 5 times.
[0058] The setting of the amount and selection range of alkali solution is intended to achieve a synergistic effect between appropriate amounts of alkali solution and specific alkaline substances and the aforementioned types of oxidants, thereby promoting the formation of stable precipitates of oxidized manganese ions and achieving efficient manganese recovery. Furthermore, by optimizing the amount and selection range of alkali solution, not only is the efficiency and purity of manganese recovery improved, but other impurity ions that may be introduced into the system are also reduced, simplifying subsequent processing steps and facilitating a more efficient and cleaner production method.
[0059] Furthermore, the precipitation method described above is applicable to the precipitation of heavy metal solutions that do not contain magnesium ions, and is particularly suitable for the following solutions, preferably containing the following cations: nickel ions 1 g / L to 100 g / L, cobalt ions 0.1 g / L to 30 g / L, copper ions 0.1 g / L to 50 g / L, divalent manganese ions 1 g / L to 80 g / L, and zinc ions 0.1 g / L to 30 g / L. More preferably, nickel ions 1 to 3 g / L, cobalt ions 0.1 to 1 g / L, copper ions 0.1 to 1 g / L, divalent manganese ions 1 to 5 g / L, and zinc ions 0.1 to 1 g / L. These preferred ion concentration ranges are more closely matched to the specific process flow and the control of specific conditions in each step of this disclosure, thereby optimizing the precipitation process of the heavy metal solution.
[0060] The present disclosure will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed by the present disclosure.
[0061] The following examples treat heavy metal solutions (aqueous solutions) with sulfate ions as the anion and the following cation composition:
[0062] Example 1
[0063] Recovery of nickel-cobalt hydroxide intermediates from liquid precipitation after iron and aluminum removal in the hydrometallurgical process of laterite nickel ore:
[0064] Referring to the flowchart of the precipitation method for heavy metal solutions shown in Figure 1, a manganese-containing solution with a manganese concentration of 3 g / L was prepared from a nickel-cobalt slurry phase. Sodium hydroxide was added at a stoichiometric ratio of 0.9 to manganese to initiate a manganese conversion reaction. The reaction temperature was 60°C, and the reaction time was 1 min, resulting in converted manganese precipitate. Sodium sulfite was then added to stabilize the converted manganese precipitate. The mass of sodium sulfite added was 0.1% of the converted manganese precipitate. The stabilization reaction temperature was 60°C, and the reaction time was 10 min, resulting in a stabilized manganese precipitate.
[0065] The stabilized manganese precipitate was returned to the heavy metal solution for further precipitation, yielding a precipitate slurry. The amount of manganese ions added to the stabilized manganese precipitate was 0.9 times the total molar amount of heavy metal ions in the heavy metal solution. The precipitation reaction temperature was 60℃, and the reaction time was 90 min. The precipitate slurry was continuously subjected to solid-liquid separation to obtain nickel cobalt hydroxide and a manganese-containing solution. Oxygen and ammonia were added to the manganese-containing solution for an oxidation precipitation reaction. The amount of oxidant was 3 times the molar amount of manganese ions in the manganese-containing solution, and the amount of ammonia was 2 times the molar amount of manganese ions in the manganese-containing solution. The oxidation precipitation reaction temperature was 60℃, and the reaction time was 400 min. After the reaction was complete, a manganese product was obtained. The resulting nickel cobalt hydroxide had a water content of 45%, a nickel content of 40%, and a manganese content of 6%.
[0066] Example 2
[0067] Liquid phase precipitation enrichment after leaching of ternary lithium batteries:
[0068] Referring to the flowchart of the precipitation method for heavy metal solutions shown in Figure 1, a manganese-containing solution containing 15 g / L of manganese in the liquid phase after leaching from a ternary lithium battery was used as the manganese ion-containing solution. Sodium hydroxide was added at 0.9 times the stoichiometric molar ratio with manganese to initiate a manganese conversion reaction. The reaction temperature was 60°C, and the reaction time was 1 min, resulting in converted manganese precipitate. Sodium sulfite was then added to stabilize the converted manganese precipitate. The mass of sodium sulfite added was 0.5% of the converted manganese precipitate, and the stabilization reaction temperature was 60°C, with a reaction time of 10 min, yielding a stabilized manganese precipitate.
[0069] The stabilized manganese precipitate was returned to the heavy metal solution for further precipitation, yielding a precipitate slurry. The amount of manganese ions added to the stabilized manganese precipitate was 0.9 times the total molar amount of heavy metal ions in the heavy metal solution. The precipitation reaction temperature was 60℃, and the reaction time was 90 min. The precipitate slurry was then subjected to continuous solid-liquid separation to obtain nickel cobalt hydroxide and a manganese-containing solution. Oxygen and ammonia were added to the manganese-containing solution for an oxidation precipitation reaction. The amount of oxidant was 3 times the molar amount of manganese ions in the manganese-containing solution, and the amount of ammonia was 2 times the molar amount of manganese ions in the manganese-containing solution. The oxidation precipitation reaction temperature was 60℃, and the reaction time was 400 min. After the reaction was complete, a manganese product was obtained. The resulting nickel cobalt hydroxide had a water content of 45%, a nickel content of 41%, and a manganese content of 7%.
[0070] Example 3
[0071] The only difference between this embodiment and Example 1 is that the slurry phase after nickel-cobalt precipitation contains 20 g / L of manganese, and finally nickel-cobalt hydroxide is obtained. The water content is 45%, the nickel content is 39%, and the manganese content is 8%.
[0072] Example 4
[0073] The only difference between this embodiment and Example 1 is that the slurry phase after nickel-cobalt precipitation contains 30 g / L of manganese, and finally nickel-cobalt hydroxide is obtained. The water content is 40%, the nickel content is 39%, and the manganese content is 8.5%.
[0074] Example 5
[0075] The only difference between this embodiment and Example 1 is that the slurry phase after nickel-cobalt precipitation contains 1 g / L of manganese, and finally nickel-cobalt hydroxide is obtained. The water content is 55%, the nickel content is 38%, and the manganese content is 5.5%.
[0076] Example 6
[0077] The only difference between this embodiment and Example 1 is that the slurry phase after nickel-cobalt precipitation contains 80 g / L of manganese, and finally nickel-cobalt hydroxide is obtained. After testing, its water content is 50%, nickel content is 37%, and manganese content is 10%.
[0078] Example 7
[0079] The only difference between this embodiment and Example 1 is that the alkaline substance is a combination of sodium hydroxide and potassium hydroxide, with a mass ratio of sodium hydroxide to potassium hydroxide of 4:4. The final product is nickel cobalt hydroxide, which, upon testing, has a water content of 48%, a nickel content of 40%, and a manganese content of 6%.
[0080] Example 8
[0081] The only difference between this embodiment and Example 1 is that the alkaline substance is a combination of sodium hydroxide and potassium hydroxide, with a mass ratio of sodium hydroxide to potassium hydroxide of 1:4. The final product is nickel cobalt hydroxide, which, upon testing, has a water content of 50%, a nickel content of 40.5%, and a manganese content of 6.5%.
[0082] Example 9
[0083] The only difference between this embodiment and Example 1 is that sodium hydroxide was added at 0.8 times the stoichiometric ratio of sodium hydroxide to manganese to carry out the manganese conversion reaction, and finally nickel cobalt hydroxide was obtained. The water content was 44%, the nickel content was 41%, and the manganese content was 5.5%.
[0084] Example 10
[0085] The only difference between this embodiment and Example 1 is that sodium hydroxide was added at 0.1 times the stoichiometric ratio of sodium hydroxide to manganese to carry out the manganese conversion reaction, and finally nickel cobalt hydroxide was obtained. The water content was 43%, the nickel content was 41%, and the manganese content was 5%.
[0086] Example 11
[0087] The only difference between this embodiment and Example 1 is that sodium hydroxide was added at 1.5 times the stoichiometric ratio of sodium hydroxide to manganese to carry out the manganese conversion reaction, and finally nickel cobalt hydroxide was obtained. The water content was 55%, the nickel content was 38%, and the manganese content was 11%.
[0088] Example 12
[0089] The only difference between this embodiment and Example 1 is that the temperature of the manganese conversion reaction is 100°C and the reaction time is 5 minutes, ultimately yielding nickel cobalt hydroxide. Upon testing, its water content is 42%, nickel content is 41%, and manganese content is 5%.
[0090] Example 13
[0091] The only difference between this embodiment and Example 1 is that the temperature of the manganese conversion reaction is 25°C and the reaction time is 30 min, and the final product is nickel cobalt hydroxide. The water content is 50%, the nickel content is 41%, and the manganese content is 5%.
[0092] Example 14
[0093] The only difference between this embodiment and Example 1 is that the stabilization reaction temperature is 100°C and the stabilization reaction time is 5 minutes, resulting in nickel cobalt hydroxide. Upon testing, its water content is 45%, nickel content is 40%, and manganese content is 5%.
[0094] Example 15
[0095] The only difference between this embodiment and Example 1 is that the stabilization reaction temperature is 25°C and the stabilization reaction time is 180 min, and the final product is nickel cobalt hydroxide. The test results show that the water content is 45%, the nickel content is 39.5%, and the manganese content is 7%.
[0096] Example 16
[0097] The only difference between this embodiment and Example 1 is that the mass of sodium sulfite added is 5% of the converted manganese precipitate, and the final product is nickel cobalt hydroxide. The test results show that the water content is 45%, the nickel content is 40.5%, and the manganese content is 6.3%.
[0098] Example 17
[0099] The only difference between this embodiment and Example 1 is that L-ascorbic acid was added to stabilize the converted manganese precipitate, ultimately yielding nickel cobalt hydroxide. Testing revealed that it contained 45% water, 41% nickel, and 6.2% manganese.
[0100] Example 18
[0101] The only difference between this embodiment and Example 1 is that the amount of manganese ions added to the stable manganese precipitate is 1 times the total molar amount of heavy metal ions in the heavy metal solution, and finally nickel cobalt hydroxide is obtained. After testing, its water content is 45.3%, nickel content is 40.1%, and manganese content is 6.1%.
[0102] Example 19
[0103] The only difference between this embodiment and Example 1 is that the amount of manganese ions added to the stable manganese precipitate is 0.2 times the total molar amount of heavy metal ions in the heavy metal solution, and finally nickel cobalt hydroxide is obtained. After testing, its water content is 45.1%, nickel content is 39.5%, and manganese content is 7%.
[0104] Example 20
[0105] The only difference between this embodiment and Example 1 is that the amount of oxidant used is 1 times the molar amount of manganese ions in the manganese-containing solution, and the amount of ammonia used is 1 times the molar amount of manganese ions in the manganese-containing solution. Finally, nickel cobalt hydroxide is obtained. After testing, its water content is 46%, nickel content is 41.2%, and manganese content is 5%.
[0106] Example 21
[0107] The only difference between this embodiment and Example 1 is that the amount of oxidant used is 0.5 times the molar amount of manganese ions in the manganese-containing solution, and the amount of ammonia water used is 0.5 times the molar amount of manganese ions in the manganese-containing solution. Finally, nickel cobalt hydroxide is obtained. After testing, its water content is 45.2%, nickel content is 40%, and manganese content is 6.1%.
[0108] Comparative Example 1
[0109] The difference from Example 1 is that the heavy metal solution was directly subjected to a precipitation reaction with a pre-prepared 20% sodium hydroxide aqueous solution for 0.5 hours at a temperature of 60°C to obtain a precipitate slurry. The precipitate slurry was then subjected to continuous solid-liquid separation to obtain nickel-cobalt hydroxide and a precipitated solution. The nickel-cobalt hydroxide was found to have a water content of 80%, a nickel content of 30%, and a manganese content of 20%.
[0110] Comparative Example 2
[0111] The difference from Example 1 is that: the liquid phase containing 15 g / L of manganese after leaching the ternary battery is used as a manganese ion-containing solution, and sodium hydroxide is added at 0.9 times the stoichiometric molar ratio with manganese to carry out the manganese conversion reaction. The temperature of the manganese conversion reaction is 60°C and the reaction time is 1 min. After the reaction, converted manganese precipitate is obtained.
[0112] The converted manganese precipitate was directly returned to the heavy metal solution for precipitation, yielding a precipitate slurry. The amount of manganese ions added to the converted manganese precipitate was 0.9 times the total molar amount of heavy metal ions in the heavy metal solution. The precipitation reaction temperature was 60℃, and the reaction time was 90 min. The precipitate slurry was then subjected to continuous solid-liquid separation to obtain nickel cobalt hydroxide and a manganese-containing solution. Oxygen and ammonia were added to the manganese-containing solution for an oxidation precipitation reaction. The amount of oxidant was 3 times the molar amount of manganese ions in the manganese-containing solution, and the amount of ammonia was 2 times the molar amount of manganese ions in the manganese-containing solution. The oxidation precipitation reaction temperature was 60℃, and the reaction time was 400 min. After the reaction was complete, a manganese product was obtained, in which the obtained nickel cobalt hydroxide had a water content of 80%, a nickel content of 34%, and a manganese content of 15%.
[0113] Comparative Example 3
[0114] The difference from Example 2 is that: after leaching the ternary battery, the liquid phase containing 15 g / L of manganese was used as a manganese ion-containing solution. Sodium hydroxide was added at 0.9 times the stoichiometric molar ratio with manganese to carry out the manganese conversion reaction. The temperature of the manganese conversion reaction was 60°C and the reaction time was 1 min. After the reaction, converted manganese precipitate was obtained.
[0115] Manganese precipitate was returned to the heavy metal solution for further precipitation, yielding a precipitate slurry. The amount of manganese ions added to the precipitate was 0.9 times the total molar amount of heavy metal ions in the heavy metal solution. The precipitation reaction was carried out at 60°C for 90 minutes. The precipitate slurry was then subjected to continuous solid-liquid separation to obtain nickel cobalt hydroxide and a manganese-containing solution. Oxygen and ammonia were added to the manganese-containing solution for an oxidation precipitation reaction. The amount of oxidant was three times the molar amount of manganese ions in the manganese-containing solution, and the amount of ammonia was twice the molar amount of manganese ions in the manganese-containing solution. The oxidation precipitation reaction was carried out at 60°C for 400 minutes. After the reaction was complete, a manganese product was obtained. The resulting nickel cobalt hydroxide contained 70% water, 34% nickel, and 14% manganese.
[0116] As can be seen from the above description, the embodiments of this disclosure achieve the following technical effects:
[0117] This disclosure proposes a method of converting and stabilizing an alkaline substance (i.e., a precipitant) with manganese to generate a stable manganese precipitate, namely manganese hydroxide or oxide. This stable manganese precipitate is then used to precipitate a heavy metal solution. This process not only achieves heavy metal enrichment but also ensures the structural stability and reaction efficiency of the heavy metal precipitate through the manganese conversion and stabilization reactions, avoiding sodium ion pollution and treatment difficulties associated with traditional precipitants (such as alkali metals). Furthermore, the obtained heavy metal precipitate product has low water content, significantly improved sedimentation and filtration performance, and the manganese in the precipitated solution can be recovered through an oxidation precipitation reaction, solving the system pollution problem. In addition, thanks to the combined manganese conversion and stabilization steps, the stable manganese precipitate obtained in this disclosure exhibits excellent chemical properties in the precipitation reaction of step S300, thereby improving not only the recovery rate and product quality of heavy metal ions but also the precipitation efficiency of heavy metals such as nickel and cobalt, achieving efficient resource recycling. This solves the problems of poor sedimentation and filtration performance, high water content, and low precipitation efficiency of precipitates in existing technologies for heavy metal precipitation from heavy metal solutions.
[0118] The above are merely preferred embodiments of this disclosure and are not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.
Claims
1. A method for precipitating a heavy metal solution, wherein the cations in the heavy metal solution include nickel ions, cobalt ions, copper ions, zinc ions, and manganese ions, characterized in that, The precipitation method includes: Step S100: A manganese-containing solution is used to carry out a manganese-converting reaction on an alkaline substance to obtain a converted manganese precipitate; Step S200: The converted manganese precipitate is stabilized using a stabilizer to obtain a stable manganese precipitate; Step S300: The stabilized manganese precipitate is added to the heavy metal solution to carry out a precipitation reaction, thereby obtaining a precipitate slurry; Step S400: The precipitated slurry is continuously subjected to solid-liquid separation to obtain heavy metal precipitate and manganese-containing solution; In step S500, the raw materials including the manganese-containing solution, oxidant and alkaline solution are subjected to an oxidation precipitation reaction to obtain a precipitated liquid and a manganese product.
2. The precipitation method for heavy metal solution according to claim 1, characterized in that, In step S100, the mass concentration of manganese ions in the manganese ion-containing solution is 1 g / L to 300 g / L.
3. The precipitation method for heavy metal solution according to claim 1, characterized in that, In step S100, the heavy metal solution is selected from any one of the following: the iron and aluminum removal solution of laterite nickel ore acid leaching solution, the battery material black powder leaching solution in the field of lithium battery recycling, and the copper-cobalt solution in copper-cobalt hydrometallurgical process.
4. The precipitation method of the heavy metal solution according to any one of claims 1 to 3, characterized in that, In step S100, the alkaline substance is selected from any one or more of hydroxides, alkaline earth metal oxides, carbonates, and bicarbonates. Specifically, the hydroxide is selected from any one or more of sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, ammonium hydroxide, and lithium hydroxide; the alkaline earth metal oxide is selected from any one or more of magnesium oxide and calcium oxide; the carbonate is selected from any one or more of magnesium carbonate, calcium carbonate, potassium carbonate, sodium carbonate, and ammonium carbonate; and the bicarbonate is selected from any one or more of magnesium bicarbonate, calcium bicarbonate, potassium bicarbonate, sodium bicarbonate, and ammonium bicarbonate.
5. The precipitation method of the heavy metal solution according to any one of claims 1 to 3, characterized in that, In step S100, the alkaline substance is added at a ratio of 0.1 to 3 times the chemical reaction stoichiometric ratio of the alkaline substance to manganese ions to form manganese precipitate.
6. The precipitation method of the heavy metal solution according to any one of claims 1 to 3, characterized in that, In step S100, the temperature of the manganese conversion reaction is 25℃~100℃, and the time of the manganese conversion reaction is 0.1min~30min.
7. The precipitation method of the heavy metal solution according to any one of claims 1 to 3, characterized in that, In step S100, the manganese ion-containing solution is derived from any one of the manganese-containing solution, the liquid phase after leaching from a ternary battery, and the liquid phase of the slurry after a stage of nickel-cobalt precipitation.
8. The precipitation method of the heavy metal solution according to any one of claims 1 to 3, characterized in that, In step S200, the temperature of the stabilization reaction is 25℃~100℃, and the time of the stabilization reaction is 0.1min~180min.
9. The precipitation method of the heavy metal solution according to any one of claims 1 to 3, characterized in that, In step S200, the mass of the stabilizer is 0.1% to 30% of the mass of the converted manganese precipitate.
10. The precipitation method of the heavy metal solution according to any one of claims 1 to 3, characterized in that, In step S200, the stabilizer is selected from any one or more of glucose, sulfur dioxide, sulfite, L-ascorbic acid, alcohols and aldehydes.
11. The precipitation method of the heavy metal solution according to any one of claims 1 to 3, characterized in that, In step S300, the ratio of the total molar amount of heavy metal ions in the heavy metal solution to the molar amount of manganese ions in the stable manganese precipitate is 1:0.1 to 5.
12. The precipitation method of the heavy metal solution according to any one of claims 1 to 3, characterized in that, In step S300, the temperature of the precipitation reaction is 25℃~100℃, and the time of the precipitation reaction is 0.1min~600min.
13. The precipitation method of the heavy metal solution according to any one of claims 1 to 3, characterized in that, In step S500, the oxidant is selected from any one or more of air, oxygen, oxygen-enriched substances, ozone, hydrogen peroxide, persulfate, hypochlorite, and perchlorate.
14. The precipitation method of the heavy metal solution according to any one of claims 1 to 3, characterized in that, In step S500, the amount of oxidant used is 0.5 to 5 times the molar amount of manganese ions in the manganese-containing solution.
15. The precipitation method of the heavy metal solution according to any one of claims 1 to 3, characterized in that, In step S500, the amount of alkali solution used is 0.5 to 5 times the molar amount of manganese ions in the manganese-containing solution, and the alkali solution is selected from any one or more of ammonia, potassium hydroxide, sodium hydroxide, and calcium hydroxide.