A method for cooperatively treating ferromanganese alloy slag and manganese oxide slag to prepare battery-grade manganese sulfate solution

Abstract

The application belongs to the technical field of solid waste resource utilization in hydrometallurgy industry, and particularly relates to a method for preparing battery-grade manganese sulfate solution by synergistically treating manganese-iron alloy slag and manganese oxide slag, comprising the following steps: S1, obtaining manganese-iron alloy slag and manganese oxide slag as raw materials; S2, mixing and pre-adjusting the manganese-iron alloy slag, the manganese oxide slag, water and sulfuric acid to obtain a second slurry by acid leaching; S3, adding manganese powder into the second slurry to perform a first reaction, and filtering to obtain a first filtrate; S4, adding manganese sulfide slurry into the first filtrate to perform a second reaction, filtering to obtain a second filtrate, and obtaining a third filtrate after the second filtrate is refined and de-magnetized; S5, performing first high-temperature crystallization on the third filtrate to obtain first crystals, dissolving the first crystals in water, performing second high-temperature crystallization to obtain second crystals, dissolving the second crystals in water, and de-magnetizing to obtain battery-grade manganese sulfate solution. The application adopts a synergistic acid leaching process, consumes manganese-iron alloy slag and manganese oxide slag, and produces battery-grade manganese sulfate solution.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of solid waste resource utilization in hydrometallurgical industry, and particularly relates to a method for preparing battery-grade manganese sulfate solution by synergistically treating manganese-iron alloy slag and manganese oxide slag. BACKGROUND

[0002] Manganese-iron alloy is an important additive for steelmaking, and a large amount of alloy slag containing metallic manganese and iron is generated in the production process. The manganese in this part of material mainly exists in the metallic valence state, and has low chemical activity. In the traditional acid dissolution recovery process, the acid consumption is high, and hydrogen gas is generated, which exists a safety risk.

[0003] The production process of electrolytic manganese, potassium permanganate, and cobalt hydroxide or nickel hydroxide generates a precipitate slag, which is mainly manganese oxide slag and mainly composed of MnO2, MnO(OH) (containing nickel, cobalt, etc.). This slag is usually regarded as hazardous solid waste, and the storage treatment not only occupies land, but also exists the risk of environmental pollution.

[0004] Manganese is an important strategic metal and is widely used in the fields of steel, battery, chemical industry, etc. The high-quality manganese ore resources are increasingly exhausted and the price is rising. It is necessary to recover and treat the solid hazardous waste containing manganese for long-term development. The existing recovery and treatment of solid hazardous waste containing manganese has the following problems:

[0005] High cost of acid leaching auxiliary materials: single treatment of manganese-iron alloy sulfuric acid leaching reaction is slow and incomplete (80-90% leaching rate of manganese at high temperature and pressure), and high temperature and pressure or introduction of fluorides and other solubilizers are needed, which seriously corrodes the equipment and introduces new impurities. In addition, the acid dissolution process will generate a large amount of hydrogen gas, and the safety of hydrogen gas needs to be considered in production. If roasting oxidation is used before acid leaching, the process is long, the energy consumption is high, and waste gas is generated. Single treatment of manganese oxide slag needs reduction acid leaching, because it is in high valence state, a large amount of external reducing agent (SO2, sodium pyrosulfite, sodium sulfite, ferrous sulfate, etc.) needs to be added, which has high cost and easily introduces impurities, increases the burden and complexity of subsequent liquid treatment. There is a lack of synergistic treatment, and a process for preparing battery-grade manganese sulfate solution with a short process;

[0006] High cost and easy introduction of impurities: aluminum removal usually uses alkali to remove, sodium carbonate, calcium carbonate, sodium hydroxide, calcium hydroxide and other alkali reagents are used to increase the pH to remove aluminum; iron removal: trivalent iron is precipitated and removed by adding alkali reagents to increase the pH, and divalent iron additionally needs to add an oxidizing agent (hydrogen peroxide or sodium chlorate, etc.); calcium and magnesium removal: sodium fluoride is added for precipitation removal. These auxiliary materials consume a lot of, and easily introduce impurities. Therefore, there is an urgent need for a process for efficiently preparing battery-grade manganese sulfate with low auxiliary material and energy consumption production cost and simple process. SUMMARY

[0007] To solve the above technical problems, the application provides a method for preparing battery-grade manganese sulfate solution by synergistically treating manganese-iron alloy slag and manganese oxide slag, comprising the following steps: S1, obtaining manganese-iron alloy slag and manganese oxide slag as raw materials, the molar ratio of manganese in the manganese-iron alloy slag to manganese in the manganese oxide slag is (1-1.2):1, wherein the composition of the manganese-iron alloy slag includes Mn: 70%-85%, Fe: 8%-12%, and the rest is Co, Ni, Cu, Ca and inevitable impurities, in terms of mass percentage; the composition of the manganese oxide slag includes Mn: 30%-52%, Fe: 1%-3%, Al: 1%-4%, Ni: 0-1%, Co: 0-1%, Si: 0-1%, and the rest is inevitable impurities; S2, mixing and pre-adjusting the manganese-iron alloy slag, the manganese oxide slag, water and sulfuric acid to obtain a first slurry, and adding sulfuric acid to the first slurry to obtain a second slurry; S3, adding manganese powder to the second slurry to perform a first reaction, and filtering to obtain a first filtrate and manganese-aluminum slag; S4, adding manganese sulfide slurry to the first filtrate to perform a second reaction, filtering to obtain a second filtrate and impurity removal slag, and performing precision filtration and magnetic removal on the second filtrate to obtain a third filtrate; S5, performing first high-temperature crystallization on the third filtrate to obtain a first mother liquor and a first crystal, dissolving the first crystal in water, performing second high-temperature crystallization to obtain a second mother liquor and a second crystal, dissolving the second crystal in water and removing the magnetism to obtain battery-grade manganese sulfate solution.

[0008] As a preferred scheme of the method for preparing battery-grade manganese sulfate solution by synergistically treating manganese-iron alloy slag and manganese oxide slag, in step S1, the mesh number of the manganese-iron alloy slag is 80-300 mesh.

[0009] As a preferred scheme of the method for preparing battery-grade manganese sulfate solution by synergistically treating manganese-iron alloy slag and manganese oxide slag, in step S2, the pH of the first slurry is 3-4, the temperature of the acid leaching is 70-80℃, the time of the acid leaching is 3-4h, and the pH of the second slurry is 1.5-2.

[0010] As a preferred scheme of the method for preparing battery-grade manganese sulfate solution by synergistically treating manganese-iron alloy slag and manganese oxide slag, in step S3, the pH of the first reaction is 3.3-3.6, the time of the first reaction is 2-3h, the manganese-aluminum slag is recycled to step S3 for the first reaction, and when the Al content in the manganese-aluminum slag is ≥18wt%, the manganese-aluminum slag is subjected to open circuit treatment.

[0011] As a preferred scheme of the method for preparing battery-grade manganese sulfate solution by synergistically treating manganese-iron alloy slag and manganese oxide slag, in step S4, the pH of the second reaction is 5-6, the time of the second reaction is 1-2h, and the impurity removal slag is subjected to open circuit treatment.

[0012] As a preferred scheme of the method for cooperatively treating manganese-iron alloy slag and manganese oxide slag to prepare battery-grade manganese sulfate solution, in the step S5, the temperature of the first high-temperature crystallization is 160-170 DEG C, and the temperature of the second high-temperature crystallization is 160-170 DEG C.

[0013] As a preferred scheme of the method for cooperatively treating manganese-iron alloy slag and manganese oxide slag to prepare battery-grade manganese sulfate solution, the step S5 further comprises adding sodium sulfide into the first mother liquor to perform a third reaction, filtering to obtain a fourth filtrate and manganese sulfide slag, and circulating the second mother liquor into the third filtrate to perform the first high-temperature crystallization.

[0014] As a preferred scheme of the method for cooperatively treating manganese-iron alloy slag and manganese oxide slag to prepare battery-grade manganese sulfate solution, in the step S5, the fourth filtrate is circulated into the step S2 to perform mixing pre-adjustment, the manganese sulfide slag is circulated into the step S4 to perform the second reaction, when the mass ratio of Mn and Na in the battery-grade manganese sulfate solution is ≤1000:1, the fourth filtrate is subjected to open circuit treatment, is put into a sodium sulfate evaporation system to perform salt production or is discharged.

[0015] As a preferred scheme of the method for cooperatively treating manganese-iron alloy slag and manganese oxide slag to prepare battery-grade manganese sulfate solution, in the step S5, the battery-grade manganese sulfate solution meets the first-class product and above standards in T / ATCRR11-2020 Battery-Grade Manganese Sulfate Solution.

[0016] As a preferred scheme of the method for cooperatively treating manganese-iron alloy slag and manganese oxide slag to prepare battery-grade manganese sulfate solution, in the step S2, the total leaching rate of manganese in the manganese-iron alloy slag and the manganese oxide slag is ≥99%; and in the step S5, the comprehensive recovery rate of the manganese element is ≥98%.

[0017] The beneficial effects of the present application are as follows:

[0018] The present application provides a method for cooperatively treating manganese-iron alloy slag and manganese oxide slag to prepare battery-grade manganese sulfate solution, which adopts a whole-process technology combining processes such as "manganese-iron alloy slag and manganese oxide slag cooperatively adding acid leaching + manganese powder removing aluminum + sulfidation removing iron + secondary high-temperature crystallization + precise deployment", reduces auxiliary material and energy consumption production cost, and proposes a new, simple and efficient process for preparing battery-grade manganese sulfate; the specific principle is as follows:

[0019] The Mn leaching rate of the manganese-iron alloy slag is only 80-90% when using single atmospheric high-temperature leaching, and single treatment of the manganese-iron alloy slag will produce a large amount of hydrogen, which is high in production risk; the Mn leaching rate of the manganese oxide slag is more than 98% when using atmospheric high-temperature reduction leaching, and a large amount of external reducing agent needs to be added for single treatment of the manganese oxide slag, which is high in auxiliary material cost and easy to introduce impurities. When the manganese-iron alloy slag and the manganese oxide slag are treated cooperatively: the elemental manganese in the manganese-iron alloy slag and the manganese dioxide in the manganese oxide slag undergo a reduction reaction, and a self-oxidation-reduction reaction occurs, and the total Mn leaching rate of the manganese-iron alloy slag and the manganese oxide slag is ≥99%; compared with the prior art, the hydrogen production is reduced by more than 60%, and the acid consumption is reduced by more than 50%; the cooperative treatment greatly improves the Mn leaching rate of the manganese-iron alloy slag, reduces hydrogen, reduces the acid leaching acid consumption of the manganese oxide slag and the manganese-iron alloy slag by more than 50%, cancels the external reducing agent used for leaching of the manganese oxide slag, and the reducing agent accounts for 50%-55% of the cost of the Mn leaching of the manganese oxide slag, thereby reducing the production cost. The purpose of pre-adjusting the pH is to avoid the production of a large amount of hydrogen by concentrated acid addition, and the raw material slurry has a pH of 5-6, which reacts violently with strong acid, the temperature rises sharply, and a large amount of hydrogen is produced; when the pH is pre-adjusted to 3-4, the reaction is relatively mild, and basically no hydrogen is produced, and the subsequent acid leaching reaction is relatively mild, the hydrogen production is small, and the pre-adjustment of the pH reduces more than 15% of the hydrogen.

[0020] The present application has the following advantages:

[0021] 1. Resource cooperation and waste-to-resource: successfully converting two solid wastes, manganese-iron alloy and manganese oxide slag, into high-value battery-grade manganese sulfate products, realizing the recycling of resources and solving the environmental pressure;

[0022] 2. Advantage complementation and consumption reduction: using the reducing property of the manganese-iron alloy to treat the manganese oxide slag, reducing the consumption of a large amount of reducing additives (SO2, sodium sulfite, etc.) required for traditional acid leaching of the manganese oxide slag; at the same time, the efficiency of the manganese-iron alloy is also improved due to the cooperative reaction, and the overall acid consumption is lower than the neutralization of single acid leaching of the two materials, and the cost is significantly reduced;

[0023] 3. Reasonable process flow and good purification effect: the designed process flow is efficient, has a ladder type, zero impurity introduction, and low-cost impurity removal process (manganese powder aluminum removal→ manganese sulfide impurity removal→ secondary high-temperature crystallization deep calcium and magnesium removal), which can deeply remove impurities such as iron, aluminum, calcium, and magnesium, and the final product can reach the product standard of battery-grade manganese sulfate solution;

[0024] 4. Win-win of environmental and economic benefits: consuming manganese-iron alloy slag and manganese oxide slag waste, and producing battery-grade manganese sulfate solution, the production process is relatively clean and meets the demand of green and sustainable development. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0026] The present application provides a method for preparing battery-grade manganese sulfate solution by synergistically processing manganese-iron alloy slag and manganese oxide slag, comprising the following steps:

[0027] S1, obtaining manganese-iron alloy slag and manganese oxide slag as raw materials, the molar ratio of manganese in the manganese-iron alloy slag to manganese in the manganese oxide slag is (1-1.2):1, wherein the composition of the manganese-iron alloy slag includes, in mass percentage: Mn: 70%-85%, Fe: 8%-12%, and the rest is Co, Ni, Cu, Ca and unavoidable impurities; the composition of the manganese oxide slag includes: Mn: 30%-52%, Fe: 1%-3%, Al: 1%-4%, Ni: 0-1%, Co: 0-1%, Si: 0-1%, and the rest is unavoidable impurities;

[0028] The mesh number of the manganese-iron alloy slag is 80-300 mesh;

[0029] Specifically, the molar ratio of manganese in the manganese-iron alloy slag to manganese in the manganese oxide slag is any one of 1:1, 1.02:1, 1.04:1, 1.06:1, 1.08:1, 1.1:1, 1.12:1, 1.14:1, 1.16:1, 1.18:1, 1.2:1 and a range between any two of them;

[0030] S2, mixing and pre-adjusting the manganese-iron alloy slag, the manganese oxide slag, water and sulfuric acid to obtain a first slurry, and adding sulfuric acid to the first slurry for acid leaching to obtain a second slurry;

[0031] The pH of the first slurry is 3-4, the temperature of the acid leaching is 70-80℃, the time of the acid leaching is 3-4h, and the pH of the second slurry is 1.5-2; the total leaching rate of manganese in the manganese-iron alloy slag and the manganese oxide slag is ≥99%;

[0032] Specifically, the pH of the first slurry is any one of 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4 and a range between any two of them; the temperature of the acid leaching is any one of 70℃, 71℃, 72℃, 73℃, 74℃, 75℃, 76℃, 77℃, 78℃, 79℃, 80℃ and a range between any two of them;

[0033] S3, adding manganese powder into the second slurry to perform a first reaction, and filtering to obtain a first filtrate and manganese-aluminum residue;

[0034] The pH of the first reaction is 3.3-3.6, the time of the first reaction is 2-3h, the manganese-aluminum residue is recycled to the step S3 to perform a first reaction, when the Al content in the manganese-aluminum residue is ≥18wt%, the manganese-aluminum residue is subjected to open circuit treatment;

[0035] S4, adding manganese sulfide slurry into the first filtrate to perform a second reaction, and filtering to obtain a second filtrate and impurity removal residue, and performing precision filtration and magnetic removal on the second filtrate to obtain a third filtrate;

[0036] The pH of the second reaction is 5-6, the time of the second reaction is 1-2h, and the impurity removal residue is subjected to open circuit treatment;

[0037] S5, performing first high-temperature crystallization on the third filtrate to obtain a first mother liquor and a first crystal, dissolving the first crystal in water, and performing second high-temperature crystallization to obtain a second mother liquor and a second crystal, dissolving the second crystal in water and removing the magnetism to obtain a battery-grade manganese sulfate solution;

[0038] The temperature of the first high-temperature crystallization is 160-170℃, and the temperature of the second high-temperature crystallization is 160-170℃; sodium sulfide is added to the first mother liquor to perform a third reaction, and filtering to obtain a fourth filtrate and manganese sulfide residue, and the second mother liquor is recycled to the third filtrate to perform the first high-temperature crystallization; the fourth filtrate is recycled to the step S2 to perform mixing and pre-adjustment, and the manganese sulfide residue is recycled to the step S4 to perform a second reaction, when the mass ratio of Mn and Na in the battery-grade manganese sulfate solution is ≤1000:1, the fourth filtrate is subjected to open circuit treatment, is put into a sodium sulfate evaporation system to prepare salt or is discharged; the battery-grade manganese sulfate solution meets the one-grade product and above standards in T / ATCRR11-2020 "Battery-grade manganese sulfate solution"; the comprehensive recovery rate of manganese element is ≥98%.

[0039] The technical scheme of the present application is further described below in combination with specific embodiments.

[0040] Embodiment 1

[0041] A method for cooperatively treating manganese-iron alloy residue and manganese oxide residue to prepare a battery-grade manganese sulfate solution, the specific preparation method comprising the following steps:

[0042] S1, obtaining manganese-iron alloy residue and manganese oxide residue as raw materials, the molar ratio of manganese in the manganese-iron alloy residue to manganese in the manganese oxide residue is 1.1:1, wherein the components of the manganese-iron alloy residue and the manganese oxide residue are shown in Table 1, Table 1 is a component table of the manganese-iron alloy residue and the manganese oxide residue in Embodiment 1, and the manganese-iron alloy residue has a mesh size of 200 mesh;

[0043] Table 1

[0044]

[0045] S2, manganese-iron alloy slag, manganese oxide slag, water, and sulfuric acid are mixed to obtain a first slurry, the solid-liquid ratio of the raw materials and water is 1:3, sulfuric acid is added to the first slurry to obtain a second slurry by acid leaching; the pH of the first slurry is 3.5, the temperature of acid leaching is 75℃, the time of acid leaching is 3.5h, and the pH of the second slurry is 1.8; the total leaching rate of manganese in the manganese-iron alloy slag and the manganese slag is 99.23%, the hydrogen gas production is 37.5% relative to Comparative Example 5, and the acid consumption is 48.7% relative to Comparative Example 5;

[0046] S3, manganese powder is added to the second slurry to perform a first reaction, and a first filtrate and manganese-aluminum slag are obtained by filtration;

[0047] The pH of the first reaction is 3.4, and the time of the first reaction is 2.5h, the manganese-aluminum slag is recycled to step S3 for the first reaction, and when the Al content in the manganese-aluminum slag is ≥18wt%, the manganese-aluminum slag is subjected to open circuit treatment;

[0048] S4, manganese sulfide slurry is added to the first filtrate to perform a second reaction, and a second filtrate and impurity removal slag are obtained by filtration, and the second filtrate is subjected to precision filtration and magnetic removal to obtain a third filtrate; the pH of the second reaction is 5.5, and the time of the second reaction is 1.5h, and the impurity removal slag is subjected to open circuit treatment;

[0049] S5, the third filtrate is subjected to first high-temperature crystallization to obtain a first mother liquor and a first crystal, the first crystal is dissolved in water and subjected to second high-temperature crystallization to obtain a second mother liquor and a second crystal, the second crystal is dissolved in water and subjected to magnetic removal to obtain battery-grade manganese sulfate solution; the temperature of the first high-temperature crystallization is 165℃, and the temperature of the second high-temperature crystallization is 165℃; sodium sulfide is added to the first mother liquor to perform a third reaction, and a fourth filtrate and manganese sulfide slag are obtained by filtration, and the second mother liquor is recycled to the third filtrate for first high-temperature crystallization; the fourth filtrate is recycled to step S2 for mixing and pre-adjustment, the manganese sulfide slag is recycled to step S4 for the second reaction, when the mass ratio of Mn and Na in the battery-grade manganese sulfate solution is ≤1000:1, the fourth filtrate is subjected to open circuit treatment, and is put into a sodium sulfate evaporation system for salt making or discharge; the battery-grade manganese sulfate solution meets the first-grade product standard in T / ATCRR11-2020 "Battery-grade manganese sulfate solution"; the comprehensive recovery rate of manganese element is 98.18%.

[0050] The composition of the battery-grade manganese sulfate solution is shown in Table 2, and Table 2 is the composition table of the battery-grade manganese sulfate solution in Example 1.

[0051] Table 2

[0052]

[0053] Example 2

[0054] A method for cooperatively processing manganese-iron alloy slag and manganese oxide slag to prepare battery-grade manganese sulfate solution, the specific preparation method steps are as follows:

[0055] S1, obtaining manganese-iron alloy slag and manganese oxide slag as raw materials, the molar ratio of manganese in the manganese-iron alloy slag to the manganese in the manganese oxide slag in the raw materials is 1.2:1, wherein the components of the manganese-iron alloy slag and the manganese oxide slag are shown in Table 3, Table 3 is a component table of the manganese-iron alloy slag and the manganese oxide slag in Example 2, and the mesh number of the manganese-iron alloy slag is 300 mesh;

[0056] Table 3

[0057]

[0058] S2, mixing and pre-adjusting the manganese-iron alloy slag, manganese oxide slag, water and sulfuric acid to obtain a first slurry, the solid-liquid ratio of the raw materials and water is 1:3, and sulfuric acid is added to the first slurry for acid leaching to obtain a second slurry; the pH of the first slurry is 4, the temperature of the acid leaching is 80°C, the time of the acid leaching is 4h, and the pH of the second slurry is 2; the total leaching rate of manganese in the manganese-iron alloy slag and the manganese slag is 99.15%, the hydrogen gas production amount is 38.3% relative to Comparative Example 5, and the acid consumption amount is 48.3% relative to Comparative Example 5;

[0059] S3, adding manganese powder to the second slurry for first reaction, and filtering to obtain a first filtrate and manganese-aluminum slag;

[0060] The pH of the first reaction is 3.6, and the time of the first reaction is 3h, the manganese-aluminum slag is recycled to step S3 for first reaction, when the Al content in the manganese-aluminum slag is ≥18wt%, the manganese-aluminum slag is subjected to open circuit treatment;

[0061] S4, adding manganese sulfide slurry to the first filtrate for second reaction, and filtering to obtain a second filtrate and impurity removal slag, and the second filtrate is subjected to precision filtration and magnetic removal to obtain a third filtrate; the pH of the second reaction is 6, and the time of the second reaction is 2h, and the impurity removal slag is subjected to open circuit treatment;

[0062] S5, the third filtrate is subjected to first high-temperature crystallization to obtain first mother liquor and first crystals, the first crystals are dissolved in water and subjected to second high-temperature crystallization to obtain second mother liquor and second crystals, the second crystals are dissolved in water and subjected to magnetic removal to obtain battery-grade manganese sulfate solution; the temperature of the first high-temperature crystallization is 170 DEG C, and the temperature of the second high-temperature crystallization is 170 DEG C; sodium sulfide is added to the first mother liquor to perform a third reaction, and filtration is performed to obtain fourth filtrate and manganese sulfide residue, and the second mother liquor is recycled to the third filtrate to perform the first high-temperature crystallization; the fourth filtrate is recycled to step S2 to perform the mixing pre-adjustment, and the manganese sulfide residue is recycled to step S4 to perform the second reaction; when the mass ratio of Mn to Na in the battery-grade manganese sulfate solution is less than or equal to 1000:1, the fourth filtrate is subjected to open circuit treatment, is put into a sodium sulfate evaporation system to prepare salt, or is discharged; the battery-grade manganese sulfate solution meets the superior product standard in T / ATCRR11-2020 "Battery-grade manganese sulfate solution"; and the comprehensive recovery rate of manganese element is 98.52%.

[0063] The composition of the battery-grade manganese sulfate solution is shown in Table 4, and Table 4 is a composition table of the battery-grade manganese sulfate solution in Example 2.

[0064] Table 4

[0065]

[0066] Example 3

[0067] A method for cooperatively treating manganese-iron alloy slag and manganese oxide slag to prepare battery-grade manganese sulfate solution, and the specific preparation method comprises the following steps:

[0068] S1, obtaining manganese-iron alloy slag and manganese oxide slag as raw materials, and the molar ratio of manganese in the manganese-iron alloy slag to manganese in the manganese oxide slag is 1:1, wherein the composition of the manganese-iron alloy slag and the manganese oxide slag is shown in Table 5, Table 5 is a composition table of the manganese-iron alloy slag and the manganese oxide slag in Example 3, and the mesh number of the manganese-iron alloy slag is 80 mesh;

[0069] Table 5

[0070]

[0071] S2, mixing and pre-adjusting the manganese-iron alloy slag, the manganese oxide slag, water and sulfuric acid to obtain a first slurry, and the solid-liquid ratio of the raw materials to water is 1:3; adding sulfuric acid to the first slurry to obtain a second slurry; the pH of the first slurry is 3, the temperature of the acid leaching is 70 DEG C, the time of the acid leaching is 3h, and the pH of the second slurry is 1.5; the total leaching rate of manganese in the manganese-iron alloy slag and the manganese slag is 99.27%, the amount of hydrogen gas generated is 39.1% relative to Comparative Example 5, and the acid consumption amount is 47.5% relative to Comparative Example 5;

[0072] S3, adding manganese powder to the second slurry to perform a first reaction, and filtering to obtain first filtrate and manganese-aluminum residue;

[0073] The pH of the first reaction is 3.3, the time of the first reaction is 2h, the manganese-aluminum slag is recycled to step S3 for the first reaction, and when the Al content in the manganese-aluminum slag is ≥18wt%, the manganese-aluminum slag is subjected to open circuit treatment;

[0074] S4, the manganese sulfide slurry is added to the first filtrate for the second reaction, and the second filtrate and the impurity removal residue are obtained by filtration, and the third filtrate is obtained by precision filtration and magnetic removal of the second filtrate; the pH of the second reaction is 5, the time of the second reaction is 1h, and the impurity removal residue is subjected to open circuit treatment;

[0075] S5, the third filtrate is subjected to first high-temperature crystallization to obtain first mother liquor and first crystals, the first crystals are dissolved in water and subjected to second high-temperature crystallization to obtain second mother liquor and second crystals, the second crystals are dissolved in water and subjected to magnetic removal to obtain battery-grade manganese sulfate solution; the temperature of the first high-temperature crystallization is 160℃, and the temperature of the second high-temperature crystallization is 160℃; sodium sulfide is added to the first mother liquor for the third reaction, and the fourth filtrate and manganese sulfide residue are obtained by filtration, and the second mother liquor is recycled to the third filtrate for the first high-temperature crystallization; the fourth filtrate is recycled to step S2 for mixing and pre-adjustment, and the manganese sulfide residue is recycled to step S4 for the second reaction; when the mass ratio of Mn and Na in the battery-grade manganese sulfate solution is ≤1000:1, the fourth filtrate is subjected to open circuit treatment, is put into a sodium sulfate evaporation system for salt making or is discharged; the battery-grade manganese sulfate solution meets the first-grade product standard in T / ATCRR11-2020 "Battery-grade manganese sulfate solution"; the comprehensive recovery rate of manganese element is 98.27%.

[0076] The composition of the battery-grade manganese sulfate solution is shown in Table 6, and Table 6 is the composition table of the battery-grade manganese sulfate solution in Example 3.

[0077] Table 6

[0078]

[0079] Comparative Example 1

[0080] The difference from Example 1 is that the pH of the first slurry in step S2 is 5, and the other steps are the same;

[0081] The total leaching rate of manganese in the manganese-iron alloy slag and the manganese slag is 98.27%, the hydrogen gas production amount is 45.8% relative to Comparative Example 5, the acid consumption amount is 48.8% relative to Comparative Example 5; the battery-grade manganese sulfate solution meets the first-grade product standard in T / ATCRR11-2020 "Battery-grade manganese sulfate solution"; the comprehensive recovery rate of manganese element is 97.13%.

[0082] Comparative Example 2

[0083] The difference from Example 1 is that the pH of the first slurry in step S2 is 2, and the other steps are the same;

[0084] The total leaching rate of manganese in the ferromanganese alloy slag and manganese slag was 98.18%, the hydrogen gas production was 42.9% relative to Comparative Example 5, the acid consumption was 48.9% relative to Comparative Example 5; the battery-grade manganese sulfate solution met the first-grade product standard in T / ATCRR11-2020 "Battery-grade Manganese Sulfate Solution"; and the comprehensive recovery rate of manganese element was 97.37%.

[0085] Comparative Example 3

[0086] The difference from Example 1 is that the molar ratio of manganese in the ferromanganese alloy slag to manganese in the manganese oxide slag in the raw material in step S1 is 1.3:1, and the other steps are the same;

[0087] The total leaching rate of manganese in the ferromanganese alloy slag and manganese slag was 98.57%, the hydrogen gas production was 46.8% relative to Comparative Example 5, the acid consumption was 55.8% relative to Comparative Example 5; the battery-grade manganese sulfate solution met the first-grade product standard in T / ATCRR11-2020 "Battery-grade Manganese Sulfate Solution"; and the comprehensive recovery rate of manganese element was 97.7%.

[0088] Comparative Example 4

[0089] The difference from Example 1 is that the molar ratio of manganese in the ferromanganese alloy slag to manganese in the manganese oxide slag in the raw material in step S1 is 0.9:1, and the other steps are the same;

[0090] The total leaching rate of manganese in the ferromanganese alloy slag and manganese slag was 98.27%, the hydrogen gas production was 43.8% relative to Comparative Example 5, the acid consumption was 52.8% relative to Comparative Example 5; the battery-grade manganese sulfate solution met the first-grade product standard in T / ATCRR11-2020 "Battery-grade Manganese Sulfate Solution"; and the comprehensive recovery rate of manganese element was 97.17%.

[0091] Comparative Example 5

[0092] The difference from Example 1 is that the ferromanganese alloy slag and the manganese slag are respectively processed alone, and the other steps are the same starting from step S3;

[0093] The total leaching rate of manganese in the ferromanganese alloy slag and manganese slag was 92.7%, the acid consumption was assumed to be 1, and the hydrogen gas production was assumed to be 1 (corresponding comparison relationship with the previous three examples and four comparative examples); the battery-grade manganese sulfate solution met the first-grade product standard in T / ATCRR11-2020 "Battery-grade Manganese Sulfate Solution"; and the comprehensive recovery rate of manganese element was 90.5%.

[0094] From the above examples and comparative examples, it can be seen that: the battery-grade manganese sulfate solution is prepared from the two manganese raw materials of manganese-iron alloy and manganese slag, and the total leaching rate of manganese in the manganese-iron alloy slag and the manganese slag is increased from 92.7% to more than 99%, and the overall manganese recovery rate is increased from 90.5% to more than 98%; the acid consumption is greatly reduced, which is reduced to 50% or less in the synergistic leaching from the acid consumption of 100% in the single treatment of the two raw materials; the hydrogen production is greatly reduced, which is reduced to 60% or less in the synergistic leaching from the hydrogen production of 100% in the single treatment of the two raw materials, and the pre-adjusted pH process can reduce the hydrogen production by about 15%.

[0095] The present application has the following advantages:

[0096] 1. Resource synergy and waste-to-resource: successfully converting manganese-iron alloy and manganese oxide slag into high-value battery-grade manganese sulfate products, realizing resource recycling and solving environmental pressure;

[0097] 2. Advantage complementation and consumption reduction: using the reducing property of manganese-iron alloy to treat manganese oxide slag, reducing the consumption of a large amount of reducing additives (SO2, sodium sulfite, etc.) required for traditional acid leaching of manganese oxide slag; at the same time, the efficiency of manganese-iron alloy is improved due to the synergistic reaction, and the overall acid consumption is lower than that of neutralization of separate acid leaching of the two materials, and the cost is significantly reduced;

[0098] 3. Reasonable process flow and good purification effect: the designed efficient, step-by-step, zero-impurity-introduction, low-cost impurity removal process flow (manganese powder aluminum removal→manganese sulfide impurity removal→secondary high-temperature crystallization deep calcium and magnesium removal) can deeply remove impurities such as iron, aluminum, calcium, and magnesium, and the final product can meet the product standard of battery-grade manganese sulfate solution;

[0099] 4. Win-win of environmental and economic benefits: consuming manganese-iron alloy slag and manganese oxide slag waste and producing battery-grade manganese sulfate solution, the production process is relatively clean and meets the demand of green and sustainable development.

[0100] The above only describes the preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation or direct / indirect application in other related technical fields based on the inventive concept of the present application and the content of the present application are included in the patent protection scope of the present application.

Claims

1. A method for synergistically treating ferromanganese slag and manganese oxide slag to produce battery grade manganese sulfate liquor, characterized in that, The method comprises the following steps: S1, obtaining manganese-iron alloy slag and manganese oxide slag as raw materials, the molar ratio of manganese in the manganese-iron alloy slag to manganese in the manganese oxide slag is (1-1.2):1, wherein the composition of the manganese-iron alloy slag includes Mn: 70%-85%, Fe: 8%-12% by mass percentage; the composition of the manganese oxide slag includes Mn: 30%-52%, Fe: 1%-3% by mass percentage; S2, mixing and pre-adjusting the manganese-iron alloy slag, the manganese oxide slag, water and sulfuric acid to obtain a first slurry, and adding sulfuric acid to the first slurry to obtain a second slurry; S3, adding manganese powder to the second slurry to perform a first reaction, and filtering to obtain a first filtrate and manganese-aluminum slag; S4, adding manganese sulfide slurry to the first filtrate to perform a second reaction, filtering to obtain a second filtrate and impurity removal slag, and performing precision filtration and magnetic removal on the second filtrate to obtain a third filtrate; S5, performing first high-temperature crystallization on the third filtrate to obtain a first mother liquor and a first crystal, dissolving the first crystal in water, performing second high-temperature crystallization to obtain a second mother liquor and a second crystal, dissolving the second crystal in water and removing the magnetism to obtain a battery-grade manganese sulfate solution; In the step S2, the pH of the first slurry is 3-4, the temperature of the acid leaching is 70-80℃, the time of the acid leaching is 3-4h, and the pH of the second slurry is 1.5-2; In the step S3, the pH of the first reaction is 3.3-3.6, and the time of the first reaction is 2-3h, the manganese-aluminum slag is recycled to the step S3 to perform the first reaction, and when the Al content in the manganese-aluminum slag is ≥18wt%, the manganese-aluminum slag is subjected to open circuit treatment.

2. A process for the preparation of battery grade manganese sulfate liquor by synergistically treating ferromanganese slag and manganese oxide slag as claimed in claim 1 wherein, In the step S1, the mesh number of the manganese-iron alloy slag is 80-300 mesh.

3. A process for the preparation of battery grade manganese sulfate liquor by synergistically treating ferromanganese slag and manganese oxide slag as claimed in claim 1 wherein, In the step S4, the pH of the second reaction is 5-6, and the time of the second reaction is 1-2h, and the impurity removal slag is subjected to open circuit treatment.

4. A process for the preparation of battery grade manganese sulfate liquor by synergistically treating ferromanganese slag and manganese oxide slag as claimed in claim 1 wherein, In the step S5, the temperature of the first high-temperature crystallization is 160-170℃, and the temperature of the second high-temperature crystallization is 160-170℃.

5. A process for the preparation of battery grade manganese sulfate liquor by synergistically treating ferromanganese slag and manganese oxide slag as claimed in claim 1 wherein, The step S5 further comprises adding sodium sulfide to the first mother liquor to perform a third reaction, filtering to obtain a fourth filtrate and manganese sulfide slag, and recycling the second mother liquor to the third filtrate to perform the first high-temperature crystallization.

6. A process for the preparation of battery grade manganese sulfate liquor by synergistically treating ferromanganese slag and manganese oxide slag as claimed in claim 5 wherein, In the step S5, the fourth filtrate is recycled to the step S2 to perform mixing and pre-adjustment, and the manganese sulfide slag is recycled to the step S4 to perform the second reaction, and when the mass ratio of Mn and Na in the battery-grade manganese sulfate solution is ≤1000:1, the fourth filtrate is subjected to open circuit treatment, is put into a sodium sulfate evaporation system to prepare salt or is discharged.

7. A process for the preparation of battery grade manganese sulfate liquor by synergistically treating ferromanganese slag and manganese oxide slag as claimed in claim 1 wherein, In the step S5, the battery-grade manganese sulfate solution meets the one-class product and above standards in T / ATCRR11-2020 "Battery-grade manganese sulfate solution".

8. A process for the preparation of battery grade manganese sulfate liquor by synergistically treating ferromanganese slag and manganese oxide slag as claimed in claim 1 wherein, In the step S2, the total leaching rate of manganese in the manganese-iron alloy slag and the manganese oxide slag is ≥99%, and in the step S5, the comprehensive recovery rate of manganese elements is ≥98%.

Images