Precipitation method of heavy metal solution

Abstract

The present invention provides a precipitation method for a heavy metal solution. 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 solution containing manganese ions to perform a manganese conversion reaction on an alkaline substance to obtain a converted manganese precipitate; step S200, using a stabilizer to perform a stabilization reaction on the converted manganese precipitate to obtain a stable manganese precipitate; step S300, adding the stable manganese precipitate to the heavy metal solution for a precipitation reaction to obtain a precipitation slurry; step S400, continuously performing solid-liquid separation on the precipitation slurry to obtain a heavy metal precipitate and a manganese-containing solution; step S500, performing an oxidative precipitation reaction on a raw material including a manganese-containing solution, an oxidant and an alkali solution to obtain a precipitated liquid and a manganese product. The method solves the problems of poor sedimentation and filtration performance of the precipitation product, high water content of the precipitation product and low precipitation efficiency when heavy metals are precipitated from a heavy metal solution.

Description

Technical Field

[0001] The invention relates to the technical field of heavy metal hydrometallurgy, and in particular to a precipitation method of a heavy metal solution. Background Art

[0002] The precipitation enrichment method is used in various fields of hydrometallurgy, such as the precipitation enrichment of nickel and cobalt in laterite nickel ore hydrometallurgy, the precipitation enrichment of nickel, cobalt and copper after battery material recovery and leaching, etc. These processes must use a precipitant to react. The general precipitant is various alkalis, but these alkaline substances will bring sodium ions into the system, and the sedimentation and filtration performance of the product after direct precipitation is very poor. The water content of the product is very high, the environmental pollution is serious, it is difficult to implement in engineering, and it brings great difficulties to production.

[0003] The nickel-cobalt precipitation process in the prior art mostly adopts the method of sodium hydroxide or sulfide precipitation, such as:

[0004] Patent CN101575676A proposes a method for precipitation iron removal and nickel-cobalt enrichment, in which the nickel-cobalt enrichment process uses a sulfiding agent for sulfidation precipitation. The patent uses a sulfiding agent, such as one or more of hydrogen sulfide, hydrogen persulfide, sodium hydrosulfide, sodium sulfide, potassium sulfide, ammonium sulfide, magnesium sulfide, and zinc sulfide, during nickel-cobalt precipitation enrichment. Hydrogen sulfide precipitation has the best effect, but hydrogen sulfide is highly toxic, has high requirements for operation and system, and the subsequent treatment of the intermediate product of sulfidation precipitation is difficult.

[0005] Patent CN102061387A discloses a two-stage nickel precipitation method, in which NaOH solution is added to a nickel sulfate solution containing magnesium, the pH is adjusted to 7.5-8.5, the reaction temperature is 20-80°C, the reaction time is 0.5-3 hours, and the obtained precipitate is separated from the mother liquor. The precipitate enters the next step, NaOH solution is added to the mother liquor, the pH is adjusted to 9-10, the reaction temperature is 20°C-80°C, the reaction time is 0.5-3 hours, and the final precipitate is separated from the mother liquor and returned to the stirring leaching system for circulation. This patent directly uses sodium hydroxide or mixed alkali solution to precipitate nickel and cobalt, introduces new sodium ions into the system, the product is small, and sedimentation is difficult, resulting in a high water content of the product.

[0006] In summary, the process of nickel-cobalt precipitation by hydrogen sulfide is widely used, with the advantages of high precipitation rate, low precipitation pH, and the ability to recover nickel-cobalt without purification under acidic conditions of the leaching solution. However, hydrogen sulfide is highly toxic, which poses great safety and environmental risks, and the subsequent treatment process of the intermediate products obtained by precipitation is also extremely cumbersome. The process of nickel-cobalt precipitation by sodium hydroxide is simple, and the equipment investment is small. However, directly using strongly alkaline sodium hydroxide as a precipitate will result in a small particle size of the nickel-cobalt hydroxide (MHP) precipitation product, the introduction of new sodium ion impurities, and poor sedimentation ability, which is not conducive to the liquid-solid separation process, and the filter cake has a high moisture content, which makes subsequent transportation and treatment difficult.

[0007] In view of this, the present invention is proposed. Summary of the invention

[0008] The main purpose of the present invention is to provide a precipitation method for a heavy metal solution to solve the problems in the prior art of poor sedimentation and filtration performance of the precipitation product, high water content of the precipitation product and low precipitation efficiency when heavy metals are precipitated from heavy metal solutions.

[0009] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a precipitation method of a heavy metal solution is provided, wherein the cations in the heavy metal solution include nickel ions, cobalt ions, copper ions, zinc ions and manganese ions, and the precipitation method includes: step S100, using a solution containing manganese ions to perform a manganese conversion reaction on an alkaline substance to obtain a converted manganese precipitate; step S200, using a stabilizer to perform a stabilization reaction on the converted manganese precipitate to obtain a stable manganese precipitate; step S300, adding the stable manganese precipitate to a heavy metal solution to perform a precipitation reaction to obtain a precipitation slurry; step S400, continuously performing solid-liquid separation on the precipitation slurry to obtain a heavy metal precipitate and a manganese-containing solution; step S500, performing an oxidative precipitation reaction on a raw material including a manganese-containing solution, an oxidant and an alkali solution to obtain a precipitated liquid and a manganese product.

[0010] Furthermore, in the above step S100, 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, preferably 1 g / L to 30 g / L, and further preferably 10 g / L to 20 g / L.

[0011] Furthermore, in the above step S100, the heavy metal solution is selected from any one of the acid leaching solution of laterite nickel ore after iron and aluminum removal, the battery material black powder leaching solution in the field of lithium battery recovery, and the copper-cobalt solution in copper-cobalt hydrometallurgy.

[0012] Further, in the above step S100, the alkaline substance is selected from any one or more of hydroxides, alkaline earth metal oxides, carbonates and bicarbonates, wherein 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; the bicarbonate is selected from any one or more of magnesium bicarbonate, calcium bicarbonate, potassium bicarbonate, sodium bicarbonate and ammonium bicarbonate; further, the alkaline substance is preferably a combination of sodium hydroxide and potassium hydroxide, and the mass ratio of sodium hydroxide to potassium hydroxide is preferably 1~4:1~4.

[0013] Furthermore, in the above step S100, based on the chemical reaction stoichiometric molar ratio of the alkaline substance and manganese ions to generate manganese precipitate, the alkaline substance is added at 0.1 to 3 times, preferably 0.8 to 1.5 times, and further preferably 0.8 to 0.9 times.

[0014] Furthermore, in the above step S100, the temperature of the manganese conversion reaction is 25°C to 100°C, preferably 60°C to 100°C, and the time of the manganese conversion reaction is 0.1min to 30min, preferably 1min to 5min.

[0015] Furthermore, in the above step S100, the solution containing manganese ions is derived from any one of a manganese-containing solution, a liquid phase after ternary battery leaching, and a slurry phase after a first stage of nickel and cobalt precipitation.

[0016] Furthermore, in the above step S200, the temperature of the stabilization reaction is 25°C to 100°C, preferably 60°C to 100°C, and the time of the stabilization reaction is 0.1 min to 180 min, preferably 30 min to 60 min.

[0017] Furthermore, in the above step S200, the mass of the stabilizer is 0.1% to 30% of the mass of the converted manganese precipitate, preferably 1% to 5%.

[0018] Furthermore, in the above step S200, 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 further, preferably, sodium sulfite.

[0019] Furthermore, in the above step S300, the ratio of the total molar amount of heavy metal ions in the heavy metal to the molar amount of manganese ions in the stable manganese precipitate is 1:0.1-5, preferably 1:0.8-1.

[0020] Furthermore, in the above step S300, the temperature of the precipitation reaction is 25°C to 100°C, preferably 60°C to 100°C, and the time of the precipitation reaction is 0.1 min to 600 min, preferably 60 min to 180 min.

[0021] Furthermore, in the above step S500, the oxidant is selected from any one or more of air, oxygen, oxygen-enriched air, ozone, hydrogen peroxide, persulfate, hypochlorite and perchlorate.

[0022] Furthermore, in the above step S500, the amount of the oxidant is 0.5 to 5 times, preferably 1 to 1.5 times, the molar amount of manganese ions in the manganese-containing solution.

[0023] Furthermore, in the above step S500, the amount of alkali solution 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 water, potassium hydroxide, sodium hydroxide and calcium hydroxide.

[0024] Applying the technical solution of the present application, the present invention proposes to convert and stabilize the alkaline substance (i.e., precipitant) with manganese to generate a stable manganese precipitate, i.e., a hydroxide or oxide of manganese, and then use the stable manganese precipitate to precipitate the heavy metal solution. This process not only realizes the enrichment of heavy metals, but also the manganese conversion reaction and stabilization reaction ensure the structural stability and reaction efficiency of the heavy metal precipitate, avoiding the sodium ion pollution and treatment difficulties caused by the use of traditional precipitants (such as alkali metals). The water content of the heavy metal precipitate product obtained is low, the sedimentation and filtration performance are greatly improved, and the manganese in the solution after precipitation can be recovered by oxidation precipitation reaction, solving the problem of system pollution. In addition, the present invention benefits from the two combined steps of manganese conversion reaction and stabilization reaction. The obtained stable manganese precipitate exhibits excellent chemical properties in the precipitation reaction in step S300, thereby not only improving the recovery rate of heavy metal ions and product quality, but also improving the precipitation efficiency of heavy metal precipitates such as nickel and cobalt, and realizing efficient recycling of resources. The invention solves the problems in the prior art that when heavy metals are precipitated from heavy metal solutions, the precipitation products have poor sedimentation and filtration performance, high water content and low precipitation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0026] Figure 1 A flow chart of a method for precipitating a heavy metal solution according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0027] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] As described in the background technology section, in the prior art, when heavy metals are precipitated from heavy metal solutions, there are problems such as poor sedimentation and filtration performance of the precipitated products, high water content of the precipitated products, and low precipitation efficiency. In order to solve this technical problem, the present application provides a precipitation method for a heavy metal solution.

[0029] In order to solve the above problems, the present invention provides a precipitation method of a heavy metal solution, wherein the cations in the heavy metal solution include nickel ions, cobalt ions, copper ions, zinc ions and manganese ions, and the precipitation method includes: step S100, using a solution containing manganese ions to perform a manganese conversion reaction on an alkaline substance to obtain a converted manganese precipitate; step S200, using a stabilizer to perform a stabilization reaction on the converted manganese precipitate to obtain a stable manganese precipitate; step S300, adding the stable manganese precipitate to the heavy metal solution to perform a precipitation reaction to obtain a precipitation slurry; step S400, continuously performing solid-liquid separation on the precipitation slurry to obtain a heavy metal precipitate and a manganese-containing solution; step S500, performing an oxidative precipitation reaction on a raw material including a manganese-containing solution, an oxidant and an alkali solution to obtain a precipitated liquid and a manganese product.

[0030] The present invention proposes to convert and stabilize an alkaline substance (i.e., a precipitant) using manganese to generate a stable manganese precipitate, i.e., a hydroxide or oxide of manganese, and then use the stable manganese precipitate to perform a precipitation reaction on a heavy metal solution. This process not only achieves the enrichment of heavy metals, but also the manganese conversion reaction and stabilization reaction ensure the structural stability and reaction efficiency of the heavy metal precipitate, avoiding the sodium ion pollution and treatment difficulties caused by the use of traditional precipitants (such as alkali metals). In addition, the water content of the heavy metal precipitate product obtained is low, the sedimentation and filtration performance are greatly improved, and the manganese in the solution after precipitation can be recovered by oxidation precipitation reaction, solving the problem of system pollution. In addition, the present invention benefits from the two combined steps of manganese conversion reaction and stabilization reaction. The obtained stable manganese precipitate exhibits excellent chemical properties in the precipitation reaction in step S300, thereby not only improving the recovery rate of heavy metal ions and product quality, but also improving the precipitation efficiency of heavy metal precipitates such as nickel and cobalt, and realizing efficient recycling of resources. The problem of poor sedimentation and filtration performance of the precipitation product, high water content of the precipitation product, and low precipitation efficiency when heavy metal solutions precipitate heavy metals in the prior art is solved.

[0031] In a preferred embodiment, in order to maintain better precipitation activity of the stable manganese precipitate and prevent it from being oxidized after being left for a long time, the stable manganese precipitate is returned to the aforementioned step S300 within 5 minutes, more preferably within 3 minutes to participate in the precipitation reaction.

[0032] In one embodiment of the present application, in the above step S100, the mass concentration of manganese ions in the manganese ion-containing solution is 1 g / L~300 g / L, preferably 1 g / L~80 g / L, preferably 1 g / L~30 g / L, and further preferably 10 g / L~20 g / L.

[0033] The mass concentration of manganese ion in the solution containing manganese ion is selected to be based on the stability and reaction efficiency of manganese ion in solution in the above range, thereby can ensure the smooth progress of the manganese conversion reaction, avoid the interference of excessive manganese ion to subsequent precipitation reaction, avoid the waste of resources simultaneously, and reduce production cost. Wherein, the mass concentration of manganese ion in the solution containing manganese ion can be 1g / L, 2g / L, 3g / L, 5g / L, 10g / L, 20g / L, 30g / L, 50g / L, 60g / L, 80g / L, 100g / L, 120g / L, 150g / L, 180g / L, 200g / L, 220g / L, 250g / L, 280g / L or 300g / L, certainly not limited to any one value in 1g / L~300g / L.

[0034] The method of the present invention can adapt to the treatment of various heavy metal solutions, has a wide range of applicability, increases its application potential in different industries, and improves the flexibility and efficiency of resource recovery. In some preferred embodiments of the present application, in the above step S100, the heavy metal solution is selected from any one of the acid leaching solution of laterite nickel ore after iron and aluminum removal, the black powder leaching solution of battery materials in the field of lithium battery recovery, and the copper-cobalt solution in the copper-cobalt hydrometallurgy. Of course, the above heavy metal solution can also be other alloys, solutions containing the above metals after waste leaching, or various types of heavy metal-containing wastewater, etc., and the metal types can be one or more. That is, the precipitation method of the heavy metal solution in the present invention has a wide range of applications and is not limited to a specific industrial field.

[0035] In one embodiment of the present application, in the above step S100, the alkaline substance is selected from any one or more of hydroxides, alkaline earth metal oxides, carbonates and bicarbonates, wherein 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; the bicarbonate is selected from any one or more of magnesium bicarbonate, calcium bicarbonate, potassium bicarbonate, sodium bicarbonate and ammonium bicarbonate.

[0036] The above alkaline substances are used to make the precipitation activity of the manganese conversion reaction more suitable, so that the types of manganese conversion precipitation can be more abundant, which is conducive to making the heavy metal precipitate particle morphology better, liquid-solid separation easier, and the final product has a lower water content and a lower manganese content. In addition, the above alkaline substances are widely available, economical, efficient and environmentally friendly. Using these specific alkaline substances as precipitants can effectively avoid the impurity ions introduced when traditional precipitants are used, optimize the purity and performance of the precipitate, reduce the difficulty of subsequent treatment, and help to achieve a cleaner production process. Further, the alkaline substance is preferably a combination of sodium hydroxide and potassium hydroxide, and the mass ratio of sodium hydroxide to potassium hydroxide is preferably 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, and is certainly not limited to the mass ratio of sodium hydroxide to potassium hydroxide being 1~4:1~4. Any one of the ratios.

[0037] In order to make the alkali transfer reaction more stable and the stability of the formed stable manganese precipitation higher, in a preferred embodiment, in the above-mentioned step S100, the chemical reaction stoichiometric molar ratio of the alkaline substance and the manganese ion reaction to generate the manganese precipitation is used as a benchmark, and the alkaline substance is added with 0.1 times to 3 times, preferably with 0.8 times to 1.5 times, and further preferably with 0.8 times to 0.9 times. The addition amount of the alkaline substance is controlled within the above range, on the one hand, the manganese transfer reaction is promoted to be more stable, and on the other hand, the amount of the stable manganese precipitation generated is more suitable, thereby promoting the precipitation reaction to be more efficient and stable. The alkaline substance can be added with 0.1 times, 0.2 times, 0.3 times, 0.4 times, 0.5 times, 0.6 times, 0.7 times, 0.8 times, 0.9 times, 1 times, 1.1 times, 1.2 times, 1.3 times, 1.4 times, 1.5 times, 2 times, 2.3 times, 2.5 times, 2.8 times or 3 times, and is certainly not limited to any value in 0.1 times to 3 times.

[0038] In addition, the setting of the above range is based on the chemical equilibrium theory, which aims to achieve the best precipitation effect by precisely controlling the ratio of alkaline substances to manganese ions, while avoiding waste of resources 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.

[0039] Based on the principles of thermodynamics and kinetics, in some preferred embodiments of the present application, in the above step S100, the temperature of the manganese conversion reaction is 25°C~100°C, preferably 60°C~100°C, and the time of the manganese conversion reaction is 0.1min~30min, preferably 1min~5min. Controlling these conditions helps to make the manganese conversion reaction efficiently carried out under mild conditions, thereby helping to reduce the risks of side reactions and energy consumption that may be caused by high temperature and long-term reactions. By optimizing the above conditions of the manganese conversion reaction, not only the conversion rate of the manganese conversion reaction and the quality of the manganese conversion precipitation are improved, but also the energy consumption is reduced, which is conducive to achieving the dual benefits of economy and environmental protection. Among them, the temperature of the manganese conversion reaction can be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, of ​​course not limited to any one value in 25°C~100°C. The time of the manganese conversion reaction can be 0.1min, 1min, 2min, 3min, 4min, 5min, 6min, 8min, 10min, 12min, 14min, 16min, 18min, 20min, 23min, 25min, 28min or 30min, and is certainly not limited to any value between 0.1min and 30min.

[0040] In one embodiment of the present application, in the above step S100, the solution containing manganese ions comes from any one of a manganese-containing solution, a liquid phase after ternary battery leaching, and a slurry phase after a first stage of nickel and cobalt precipitation.

[0041] The source of the solution containing manganese ions in step S100 is wide, and it is emphasized that the solution containing manganese ions can be a manganese ion-containing byproduct in the recovery process of lithium-ion batteries, or a manganese ion-containing byproduct in the nickel-cobalt precipitation treatment process, and can also be a manganese-containing solution produced in the heavy metal solution precipitation process of the present application. It can be seen that through the heavy metal solution precipitation method of the present application, not only can the manganese ions in the manganese ion-containing byproducts be cleverly utilized to improve the recovery rate of heavy metal ions and product quality, but also the recycling of manganese ion-containing byproducts in the above processes is improved, thereby not only reducing raw material consumption and production costs, but also reducing waste emissions, promoting green manufacturing and sustainable development, and improving the overall economic value.

[0042] In order to make the stability of the generated stable manganese precipitate better, in some preferred embodiments of the present application, in the above step S200, the temperature of the stabilization reaction is 25°C~100°C, preferably 60°C~100°C, and the time of the stabilization reaction is 0.1min~180min, preferably 30min~60min. By controlling the stabilization reaction conditions, it is beneficial to make the stabilization process of the conversion manganese precipitation efficient and reduce the risk of forming unstable products. The stabilization reaction of the conversion manganese precipitate increases the chemical stability of the precipitate, improves the selectivity and efficiency of the subsequent precipitation reaction, and reduces the energy consumption and by-products in the treatment process, thereby optimizing the entire production process. Among them, the temperature of the stabilization reaction can be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, of ​​course, not limited to any one value in 25°C~100°C. The time of the stabilization reaction 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, and is certainly not limited to any value between 0.1 min and 180 min.

[0043] 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. Specifically, one of the three schemes can be selected according to actual conditions, which will not be repeated here.

[0044] In one embodiment of the present application, in the above step S200, the mass of the stabilizer is 0.1% to 30% of the mass of the converted manganese precipitate, preferably 1% to 5%.

[0045] The above ratio is intended to ensure the structural stability and reactivity of the converted manganese precipitate through an appropriate amount of stabilizer, and to avoid a decrease in reactivity caused by excessive stabilization. By optimizing the amount of stabilizer, not only the stability and reaction efficiency of the converted manganese precipitate are improved, but also the additional cost and handling difficulty caused by excessive stabilizer are reduced, which helps to achieve a more economical production method. Among them, 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 converted manganese precipitate, and of course is not limited to any value between 0.1% and 30%.

[0046] In order to improve the synergistic effect of the stabilizer and the manganese conversion precipitate, so that the stability of the obtained stable manganese precipitate is better, in some preferred embodiments of the present application, in the above step S200, the stabilizer is selected from any one or more of glucose, sulfur dioxide, sulfite, L-ascorbic acid, alcohol and aldehyde. These substances can effectively stabilize the manganese conversion precipitate through oxidation-reduction, complexation or adsorption, and reduce the risk of decomposition or loss of activity during subsequent treatment. And the use of these specific stabilizers not only improves the stability of the manganese conversion precipitate, but also broadens the selection range of the stabilizer, reduces the dependence on specific stabilizers, and increases the flexibility and cost control ability of the process. In addition, the preferred sulfite is sodium sulfite and / or potassium sulfite, and further, sodium sulfite is preferably used.

[0047] Based on chemical reaction theory, in some preferred embodiments of the present application, in the above step S300, the ratio of the total molar amount of heavy metal ions in the heavy metal to the molar amount of manganese ions in the stable manganese precipitate is 1:0.1~5, preferably 1:0.8~1. The setting of the above ratio is intended to promote the effective precipitation of heavy metals through an appropriate amount of stable manganese precipitate, avoiding the problems caused by insufficient or excessive precipitation agent. By controlling the molar ratio of the precipitation reaction, not only the selectivity and efficiency of the precipitation reaction are improved, but also the energy consumption and by-product generation in the precipitation process are reduced, which is conducive to improving the heavy metal recovery rate and product quality, while reducing production costs. Among them, the ratio of the total molar amount of heavy metal ions in the heavy metal 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, of course, not limited to any one value in 1:0.1~5.

[0048] Based on the principles of thermodynamics and kinetics, in some preferred embodiments of the present application, in the above step S300, the temperature of the precipitation reaction is 25°C~100°C, preferably 60°C~100°C, and the time of the precipitation reaction is 0.1min~600min, preferably 60min~180min. The above preferred conditions promote the efficient precipitation reaction under mild conditions, reducing the metal dissolution and energy waste that may be caused by high temperature and long reaction time. By optimizing the conditions of the precipitation reaction, not only the precipitation efficiency and metal recovery rate are improved, but also the environmental pollution that may be generated during the reaction is reduced, which is conducive to achieving a greener production process. Among them, the temperature of the precipitation reaction can be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, of ​​course not limited to any one value in 25°C~100°C. The time of the precipitation reaction 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, and is certainly not limited to any value between 0.1 min and 600 min.

[0049] In some embodiments of the present application, in the above step S500, the oxidant is selected from any one or more of air, oxygen, oxygen-enriched air, ozone, hydrogen peroxide, persulfate, hypochlorite and perchlorate.

[0050] These oxidants convert manganese ions in manganese-containing solutions into a precipitable state through oxidation, thus achieving manganese recovery and utilization. The use of these specific oxidants not only improves manganese recovery efficiency and reduces resource consumption, but also avoids the potential safety hazards caused by the use of strong oxidants, which is conducive to achieving a safer and more environmentally friendly production process.

[0051] In order to make the manganese ions in the manganese-containing solution more fully oxidized, based on chemical reaction theory, in some preferred embodiments of the present application, in the above-mentioned step S500, the amount of oxidant is 0.5 times to 5 times of the molar amount of manganese ions in the manganese-containing solution, preferably 1 times to 1.5 times. The setting of this ratio is intended to ensure the complete oxidation of manganese by an appropriate amount of oxidant, avoiding the problems caused by insufficient or excessive oxidant. By controlling the amount of oxidant, not only the efficient recovery of manganese is guaranteed, but also the byproducts produced by excessive oxidant are reduced, the processing cost is reduced, and the safety and environmental protection of the production process are improved. Wherein, the amount of oxidant can be 0.5 times, 0.8 times, 1 times, 1.2 times, 1.5 times, 2 times, 2.5 times, 3 times, 3.5 times, 4 times, 4.5 times or 5 times of the molar amount of manganese ions in the manganese-containing solution, and is certainly not limited to any one value in 0.5 times to 5 times.

[0052] In order to more fully precipitate the oxidized manganese ions in the manganese-containing solution, based on chemical reaction theory, in some preferred embodiments of the present application, in the above step S500, the amount of alkali solution 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 water, potassium hydroxide, sodium hydroxide and calcium hydroxide.

[0053] Among them, the amount of the oxidant can be 0.5 times, 0.8 times, 1 times, 1.2 times, 1.5 times, 2 times, 2.5 times, 3 times, 3.5 times, 4 times, 4.5 times or 5 times the molar amount of manganese ions in the manganese-containing solution, and is certainly not limited to any value between 0.5 times and 5 times.

[0054] The amount of alkali solution added and the range of materials selected are set to promote the formation of stable precipitation of oxidized manganese ions and achieve efficient recovery of manganese through the synergistic effect of appropriate amount of alkali solution and specific alkaline substances with the aforementioned types of oxidants. And by optimizing the amount of alkali solution added and the selection range, not only the efficiency and purity of manganese recovery are improved, but also other impurity ions that may be introduced into the system are reduced, and the subsequent processing steps are simplified, which is conducive to achieving a more efficient and cleaner production method.

[0055] In addition, the precipitation method of the present invention is used for the precipitation of heavy metal solutions that do not contain magnesium ions, and is particularly suitable for the following solutions, preferably the cationic components in the heavy metal solution are as follows: nickel ions 1g / L~100g / L, cobalt ions 0.1g / L~30g / L, copper ions 0.1g / L~50g / L, divalent manganese ions 1g / L~80g / L, zinc ions 0.1g / L~30g / L. Further, preferably nickel ions 1~3g / L, cobalt ions 0.1~1g / L, copper ions 0.1~1g / L, divalent manganese ions 1~5g / L, zinc ions 0.1~1g / L, and the preferred ion concentration ranges are more compatible with the specific process flow of the present application and the control of specific conditions in each step, so that the precipitation process of the heavy metal solution is more optimized.

[0056] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0057] The object treated in the following examples is a heavy metal solution (aqueous solution), the anion of which is sulfate ion, and the cation components are as follows:

[0058]

[0059] Example 1

[0060] The intermediate product of nickel and cobalt hydroxide is recovered by liquid precipitation after iron and aluminum removal in the laterite nickel ore hydrometallurgical process:

[0061] Reference Figure 1 The flowchart of the precipitation method of the heavy metal solution shown in the figure is that the manganese-containing solution is a solution containing 3 g / L manganese in the ore slurry phase after the precipitation of nickel and cobalt, and sodium hydroxide is added at 0.9 times the chemical reaction stoichiometric molar ratio with manganese to carry out a manganese conversion reaction. The temperature of the manganese conversion reaction is 60°C and the reaction time is 1 min. After the reaction, a converted manganese precipitate is obtained. Sodium sulfite is added to stabilize the converted manganese precipitate. The mass of the added sodium sulfite is 0.1% of the converted manganese precipitate. The temperature of the stabilization reaction is 60°C and the reaction time is 10 min to obtain a stable manganese precipitate.

[0062] The stable manganese precipitate is returned to the heavy metal solution for precipitation reaction to obtain a precipitation slurry. The amount of manganese ions added to the stable manganese precipitate is 0.9 times the total molar amount of heavy metal ions in the heavy metal. The precipitation reaction temperature is 60°C and the reaction time is 90 minutes. The precipitation slurry is continuously subjected to solid-liquid separation to obtain nickel cobalt hydroxide and a manganese-containing solution. Oxygen and ammonia water are added to the manganese-containing solution for oxidation precipitation reaction. The amount of oxidant is 3 times the molar amount of manganese ions in the manganese-containing solution, the amount of ammonia water is 2 times the molar amount of manganese ions in the manganese-containing solution, the oxidation precipitation reaction temperature is 60°C, the reaction time is 400 minutes, and a manganese product is obtained after the reaction is completed. Among them, the obtained nickel cobalt hydroxide has a water content of 45%, a nickel content of 40%, and a manganese content of 6%.

[0063] Example 2

[0064] Ternary battery leaching liquid precipitation enrichment:

[0065] Reference Figure 1 The flowchart of the precipitation method of the heavy metal solution shown in the figure is that the liquid phase containing manganese after leaching of the ternary battery contains 15g / L manganese as a solution containing manganese ions, and sodium hydroxide is added at 0.9 times the chemical reaction stoichiometric molar ratio with manganese to carry out a manganese conversion reaction. The temperature of the manganese conversion reaction is 60°C, and the reaction time is 1min. After the reaction, a converted manganese precipitate is obtained. Sodium sulfite is added to stabilize the converted manganese precipitate. The mass of the added sodium sulfite is 0.5% of the converted manganese precipitate. The temperature of the stabilization reaction is 60°C, and the reaction time is 10min to obtain a stable manganese precipitate.

[0066] The stable manganese precipitate is returned to the heavy metal solution for precipitation reaction to obtain precipitation slurry. The amount of manganese ions added to the stable manganese precipitate is 0.9 times the total molar amount of heavy metal ions in the heavy metal. The precipitation reaction temperature is 60°C and the reaction time is 90 minutes. The precipitation slurry is continuously subjected to solid-liquid separation to obtain nickel cobalt hydroxide and a manganese-containing solution. Oxygen and ammonia water are added to the manganese-containing solution for oxidation precipitation reaction. The amount of oxidant is 3 times the molar amount of manganese ions in the manganese-containing solution, the amount of ammonia water is 2 times the molar amount of manganese ions in the manganese-containing solution, the oxidation precipitation reaction temperature is 60°C, the reaction time is 400 minutes, and a manganese product is obtained after the reaction is completed, wherein the obtained nickel cobalt hydroxide has a water content of 45%, a nickel content of 41%, and a manganese content of 7%.

[0067] Example 3

[0068] The only difference between this embodiment and embodiment 1 is that after the first stage of nickel-cobalt precipitation, the ore slurry phase contains 20 g / L of manganese, and nickel-cobalt hydroxide is finally obtained. After testing, its water content is 45%, the nickel content is 39%, and the manganese content is 8%.

[0069] Example 4

[0070] The only difference between this embodiment and embodiment 1 is that after the first stage of nickel-cobalt precipitation, the ore slurry phase contains 30 g / L of manganese, and nickel-cobalt hydroxide is finally obtained. After testing, its water content is 40%, the nickel content is 39%, and the manganese content is 8.5%.

[0071] Example 5

[0072] The only difference between this embodiment and embodiment 1 is that: after the first stage of nickel-cobalt precipitation, the ore slurry phase contains 1 g / L of manganese, and nickel-cobalt hydroxide is finally obtained. After testing, its water content is 55%, the nickel content is 38%, and the manganese content is 5.5%.

[0073] Example 6

[0074] The only difference between this embodiment and embodiment 1 is that after the first stage of nickel-cobalt precipitation, the ore slurry phase contains 80 g / L of manganese, and nickel-cobalt hydroxide is finally obtained. After testing, its water content is 50%, the nickel content is 37%, and the manganese content is 10%.

[0075] Example 7

[0076] This embodiment is different from embodiment 1 only in that the alkaline substance is a combination of sodium hydroxide and potassium hydroxide, the mass ratio of sodium hydroxide to potassium hydroxide is 4:4, and nickel cobalt hydroxide is finally obtained. After testing, its water content is 48%, the nickel content is 40%, and the manganese content is 6%.

[0077] Example 8

[0078] The only difference between this embodiment and embodiment 1 is that the alkaline substance is a combination of sodium hydroxide and potassium hydroxide, the mass ratio of sodium hydroxide to potassium hydroxide is 1:4, and nickel cobalt hydroxide is finally obtained. After testing, its water content is 50%, the nickel content is 40.5%, and the manganese content is 6.5%.

[0079] Example 9

[0080] The only difference between this embodiment and embodiment 1 is that sodium hydroxide is added at 0.8 times the chemical reaction stoichiometric molar ratio with manganese to carry out manganese conversion reaction, and finally nickel cobalt hydroxide is obtained. After testing, its water content is 44%, the nickel content is 41%, and the manganese content is 5.5%.

[0081] Example 10

[0082] The only difference between this embodiment and embodiment 1 is that sodium hydroxide is added at 0.1 times the chemical reaction stoichiometric molar ratio with manganese to carry out manganese conversion reaction, and nickel cobalt hydroxide is finally obtained. After testing, its water content is 43%, the nickel content is 41%, and the manganese content is 5%.

[0083] Embodiment 11

[0084] The only difference between this embodiment and embodiment 1 is that sodium hydroxide is added at 1.5 times the chemical reaction stoichiometric molar ratio with manganese to carry out manganese conversion reaction, and nickel cobalt hydroxide is finally obtained. After testing, its water content is 55%, the nickel content is 38%, and the manganese content is 11%.

[0085] Example 12

[0086] The only difference between this embodiment and embodiment 1 is that the temperature of the manganese conversion reaction is 100° C., the time of the manganese conversion reaction is 5 minutes, and nickel cobalt hydroxide is finally obtained. After testing, its water content is 42%, the nickel content is 41%, and the manganese content is 5%.

[0087] Embodiment 13

[0088] The only difference between this embodiment and embodiment 1 is that the temperature of the manganese conversion reaction is 25° C., the time of the manganese conversion reaction is 30 minutes, and nickel cobalt hydroxide is finally obtained. After testing, its water content is 50%, the nickel content is 41%, and the manganese content is 5%.

[0089] Embodiment 14

[0090] The only difference between this embodiment and embodiment 1 is that the temperature of the stabilization reaction is 100° C., the time of the stabilization reaction is 5 minutes, and nickel cobalt hydroxide is finally obtained. After testing, its water content is 45%, the nickel content is 40%, and the manganese content is 5%.

[0091] Embodiment 15

[0092] The only difference between this embodiment and embodiment 1 is that the temperature of the stabilization reaction is 25° C., the time of the stabilization reaction is 180 min, and nickel cobalt hydroxide is finally obtained. After testing, its water content is 45%, the nickel content is 39.5%, and the manganese content is 7%.

[0093] Example 16

[0094] The only difference between this embodiment and embodiment 1 is that the mass of sodium sulfite added is 5% of the converted manganese precipitate, and nickel cobalt hydroxide is finally obtained. After testing, its water content is 45%, the nickel content is 40.5%, and the manganese content is 6.3%.

[0095] Embodiment 17

[0096] The only difference between this embodiment and embodiment 1 is that L-ascorbic acid is added to stabilize the converted manganese precipitate, and nickel cobalt hydroxide is finally obtained. After testing, the water content is 45%, the nickel content is 41%, and the manganese content is 6.2%.

[0097] Embodiment 18

[0098] The only difference between this embodiment and embodiment 1 is that the amount of manganese ions added in the stable manganese precipitate is 1 times the total molar amount of heavy metal ions in the heavy metal, and nickel cobalt hydroxide is finally obtained. After testing, its water content is 45.3%, the nickel content is 40.1%, and the manganese content is 6.1%.

[0099] Embodiment 19

[0100] The only difference between this embodiment and embodiment 1 is that the amount of manganese ions added in the stable manganese precipitate is 0.2 times the total molar amount of heavy metal ions in the heavy metal, and nickel cobalt hydroxide is finally obtained. After testing, its water content is 45.1%, the nickel content is 39.5%, and the manganese content is 7%.

[0101] Embodiment 20

[0102] The only difference between this embodiment and embodiment 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 water used is 1 times the molar amount of manganese ions in the manganese-containing solution. Nickel cobalt hydroxide is finally obtained. After testing, its water content is 46%, the nickel content is 41.2%, and the manganese content is 5%.

[0103] Embodiment 21

[0104] The only difference between this embodiment and embodiment 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. Nickel cobalt hydroxide is finally obtained. After testing, its water content is 45.2%, the nickel content is 40%, and the manganese content is 6.1%.

[0105] Comparative Example 1

[0106] The difference from Example 1 is that: the heavy metal solution is directly subjected to precipitation reaction with a pre-configured 20% sodium hydroxide aqueous solution, the reaction temperature is 0.5h, the reaction temperature is 60°C, and a precipitation slurry is obtained; the precipitation slurry is continuously subjected to solid-liquid separation to obtain nickel cobalt hydroxide and a precipitated solution, and the water content of the nickel cobalt hydroxide is 80%, the nickel content is 30%, and the manganese content is 20%.

[0107] Comparative Example 2

[0108] The difference from Example 1 is that: the liquid phase containing 15 g / L manganese after leaching of the ternary battery is used as a manganese ion solution, and sodium hydroxide is added at 0.9 times the chemical reaction stoichiometric molar ratio with manganese to carry out manganese conversion reaction, the temperature of the manganese conversion reaction is 60°C, the reaction time is 1 min, and a converted manganese precipitate is obtained after the reaction.

[0109] The converted manganese precipitate is directly returned to the heavy metal solution for precipitation reaction to obtain a precipitate slurry. The amount of manganese ions added in the converted manganese precipitate is 0.9 times the total molar amount of heavy metal ions in the heavy metal. The precipitation reaction temperature is 60°C and the reaction time is 90 minutes. The precipitate slurry is continuously subjected to solid-liquid separation to obtain nickel cobalt hydroxide and a manganese-containing solution. Oxygen and ammonia water are added to the manganese-containing solution for oxidation precipitation reaction. The amount of oxidant is 3 times the molar amount of manganese ions in the manganese-containing solution, the amount of ammonia water is 2 times the molar amount of manganese ions in the manganese-containing solution, the oxidation precipitation reaction temperature is 60°C, the reaction time is 400 minutes, and a manganese product is obtained after the reaction is completed, wherein the obtained nickel cobalt hydroxide has a water content of 80%, a nickel content of 34%, and a manganese content of 15%.

[0110] Comparative Example 3

[0111] The difference from Example 2 is that: the liquid phase containing 15 g / L manganese after leaching of the ternary battery is used as a manganese ion solution, and sodium hydroxide is added at 0.9 times the chemical reaction stoichiometric molar ratio with manganese to carry out manganese conversion reaction, the temperature of the manganese conversion reaction is 60°C, the reaction time is 1 min, and a converted manganese precipitate is obtained after the reaction.

[0112] The converted manganese precipitate is returned to the heavy metal solution for precipitation reaction to obtain a precipitate slurry. The amount of manganese ions added in the converted manganese precipitate is 0.9 times the total molar amount of heavy metal ions in the heavy metal. The precipitation reaction temperature is 60°C and the reaction time is 90 minutes. The precipitate slurry is continuously subjected to solid-liquid separation to obtain nickel cobalt hydroxide and a manganese-containing solution. Oxygen and ammonia water are added to the manganese-containing solution for oxidation precipitation reaction. The amount of oxidant is 3 times the molar amount of manganese ions in the manganese-containing solution, the amount of ammonia water is 2 times the molar amount of manganese ions in the manganese-containing solution, the oxidation precipitation reaction temperature is 60°C, the reaction time is 400 minutes, and a manganese product is obtained after the reaction is completed, wherein the obtained nickel cobalt hydroxide has a water content of 70%, a nickel content of 34%, and a manganese content of 14%.

[0113] It should be noted that, compared with Example 1, the amount of oxidant and ammonia water used in Example 22 is slightly lower, which will result in a lower manganese recovery rate in the final manganese product than in Example 1.

[0114] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0115] The present invention proposes to convert and stabilize an alkaline substance (i.e., a precipitant) using manganese to generate a stable manganese precipitate, i.e., a hydroxide or oxide of manganese, and then use the stable manganese precipitate to perform a precipitation reaction on a heavy metal solution. This process not only achieves the enrichment of heavy metals, but also the manganese conversion reaction and stabilization reaction ensure the structural stability and reaction efficiency of the heavy metal precipitate, avoiding the sodium ion pollution and treatment difficulties caused by the use of traditional precipitants (such as alkali metals). In addition, the water content of the heavy metal precipitate product obtained is low, the sedimentation and filtration performance are greatly improved, and the manganese in the solution after precipitation can be recovered by oxidation precipitation reaction, solving the problem of system pollution. In addition, the present invention benefits from the two combined steps of manganese conversion reaction and stabilization reaction. The obtained stable manganese precipitate exhibits excellent chemical properties in the precipitation reaction in step S300, thereby not only improving the recovery rate of heavy metal ions and product quality, but also improving the precipitation efficiency of heavy metal precipitates such as nickel and cobalt, and realizing efficient recycling of resources. The problem of poor sedimentation and filtration performance of the precipitation product, high water content of the precipitation product, and low precipitation efficiency when heavy metal solutions precipitate heavy metals in the prior art is solved.

[0116] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A precipitation method for 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 comprises: Step S100, using a solution containing manganese ions to perform a manganese conversion reaction on an alkaline substance to obtain a converted manganese precipitate; Step S200, using a stabilizer to perform a stabilization reaction on the converted manganese precipitate to obtain a stable manganese precipitate; Step S300, adding the stable manganese precipitate to the heavy metal solution to perform a precipitation reaction to obtain a precipitation slurry; Step S400, continuously performing solid-liquid separation on the precipitation slurry to obtain a heavy metal precipitate and a manganese-containing solution; Step S500, subjecting the raw materials including the manganese-containing solution, the oxidant and the alkaline solution to an oxidation precipitation reaction to obtain a precipitated liquid and a manganese product; In the step S200, the stabilizer is selected from any one or more of glucose, sulfur dioxide, sulfite, L-ascorbic acid, alcohol and aldehyde.

2. The precipitation method of heavy metal solution according to claim 1, characterized in that: In the 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 of heavy metal solution according to claim 1, characterized in that: In the step S100, the heavy metal solution is selected from any one of the acid leaching solution of laterite nickel ore after iron and aluminum removal, the battery material black powder leaching solution in the field of lithium battery recovery, and the copper-cobalt solution in copper-cobalt hydrometallurgy.

4. The precipitation method of a 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, wherein 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; 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 a heavy metal solution according to any one of claims 1 to 3, characterized in that: In the step S100, the alkaline substance is added at 0.1 to 3 times the molar ratio of the chemical reaction in which the alkaline substance reacts with the manganese ion to generate the manganese precipitate.

6. The precipitation method of a heavy metal solution according to any one of claims 1 to 3, characterized in that: In the step S100, the temperature of the manganese conversion reaction is 25° C. to 100° C., and the time of the manganese conversion reaction is 0.1 min to 30 min.

7. The precipitation method of a heavy metal solution according to any one of claims 1 to 3, characterized in that: In the step S100, the solution containing manganese ions is derived from any one of the manganese-containing solution, the liquid phase after ternary battery leaching, and the ore slurry phase after a first stage of nickel and cobalt precipitation.

8. The precipitation method of a heavy metal solution according to any one of claims 1 to 3, characterized in that: In the step S200, the temperature of the stabilization reaction is 25°C to 100°C, and the time of the stabilization reaction is 0.1 min to 180 min.

9. The precipitation method of a heavy metal solution according to any one of claims 1 to 3, characterized in that: In the 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 a heavy metal solution according to any one of claims 1 to 3, characterized in that: In the step S300, the ratio of the total molar amount of heavy metal ions in the heavy metal to the molar amount of manganese ions in the stable manganese precipitate is 1:0.1-5.

11. The precipitation method of a heavy metal solution according to any one of claims 1 to 3, characterized in that: In the step S300, the temperature of the precipitation reaction is 25°C to 100°C, and the time of the precipitation reaction is 0.1min to 600min.

12. The precipitation method of a 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 air, ozone, hydrogen peroxide, persulfate, hypochlorite and perchlorate.

13. The precipitation method of a heavy metal solution according to any one of claims 1 to 3, characterized in that: In the step S500, the amount of the oxidant is 0.5 to 5 times the molar amount of manganese ions in the manganese-containing solution.

14. The precipitation method of a heavy metal solution according to any one of claims 1 to 3, characterized in that: In the step S500, the amount of the alkali solution 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 water, potassium hydroxide, sodium hydroxide and calcium hydroxide.

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