Method for removing organic impurities from manganese sulfate solution

Abstract

The present invention provides a method for removing organic impurities from a manganese sulfate solution. The method provided in the present application comprises: step S1, providing an organic solvent aerosol, mixing the organic solvent aerosol with a manganese sulfate solution to be purified in a negative pressure state, breaking the organic solvent aerosol into an organic solvent, and the organic impurities in the manganese sulfate solution to be purified are gathered in the organic solvent to obtain a layered manganese sulfate aqueous phase solution and an organic phase dissolved with organic impurities; step S2, separating the manganese sulfate aqueous phase solution and the organic phase to obtain a purified manganese sulfate aqueous phase solution and an organic phase to be purified. The present application utilizes the high permeability and high solubility of the organic solvent aerosol to increase the probability of organic impurities in the manganese sulfate solution to be purified being dissolved and contacted with the organic solvent, and strengthens the competitive adsorption and dissolution ability of the organic solvent on the organic impurities in the aqueous phase solution, thereby effectively improving the removal efficiency of the organic impurities, and has a low metal loss rate, and can be suitable for large-scale production.

Description

Technical Field

[0001] The invention relates to the technical field of purification of manganese-containing solutions, and in particular to a method for removing organic impurities from a manganese sulfate solution. Background Art

[0002] Manganese products are mostly produced with manganese sulfate or manganese sulfate solution as intermediates. The existing raw materials used to prepare manganese sulfate include manganese ore and secondary manganese resources, including natural ores such as manganese carbonate ore, manganese oxide ore, paragenetic polymetallic ore, sulfur manganese ore and manganese nodules, as well as secondary resources such as waste power battery containing manganese, manganese smelting slag, and manganese-containing wastewater. At present, manganese products are still produced with manganese carbonate ore and manganese oxide ore as key raw materials. my country's manganese ore is mainly poor manganese ore, accounting for 93.6% of manganese resource reserves. Its low manganese grade, high impurity content, and fine particle size make it difficult to select and smelt. In addition, with the continuous consumption of manganese carbonate ore resources that are easy to acid-leach, extracting manganese from manganese oxide resources (pyrolusite, hard manganese ore, manganese oxide electrodes, etc.) has become one of the research focuses. From the existing research on the processing of manganese oxide resources, it is found that using a sulfuric acid system to reduce and extract manganese from manganese oxides to obtain manganese sulfate solution is a highly selective and economical method; this method is a cheap and efficient reducing agent research and development.

[0003] In the process of manganese oxide ore dressing and smelting, biomass such as coking wastewater, straw, waste molasses, etc. are used as reducing agents to leach manganese oxide ore. Because the reducing agents used are non-toxic, low-cost and renewable chemical resources, the leaching selectivity is relatively high, which has become one of the key focus directions of manganese extraction. In recent years, some companies have tried to use biomass to process and extract pyrolusite to produce electrolytic manganese; but from the ore-reduction leaching system, organic impurities are easily left in the obtained manganese ore leachate, and these organic impurities have a significant impact on the subsequent electrolysis process, especially when the CODcr content of strongly polar organic impurities in the manganese sulfate solution exceeds 3g / L, which significantly affects the subsequent electrolysis efficiency of manganese sulfate. In addition, the acid dissolution of organic matter contained in waste battery electrode materials, or the mixing of organic impurities in the production process, has also become an important influencing factor in the manganese electrolysis process. Therefore, for the preparation process of manganese sulfate with the participation of biomass, it is necessary to reduce the content of organic impurities in the manganese sulfate solution.

[0004] There are many methods for purifying manganese sulfate solution, mainly for treating inorganic impurities, such as Ca, Mg, K, Na and other impurities. For example, "A method for producing high-purity manganese sulfate (CN103030180A)" uses a multiple dissolution-crystallization / recrystallization method to purify manganese sulfate solution from inorganic solution. There are also reports on selective purification of manganese sulfate solution with organic phase, mostly by selective extraction of Mn 2+, metal ions to purify manganese sulfate solution, such as the patents "Purification treatment method of manganese sulfate solution (CN111285403A)", "A method for purifying manganese sulfate monohydrate (CN103145188A)". However, these purification technologies do not involve organic impurities and are difficult to apply to manganese sulfate solution systems obtained by biomass reduction. There are relatively few studies on the removal process of organic impurities in manganese sulfate solution. The paper "Removal of Residual Organic Matter from Manganese Sulfate Solution by Adsorption" (Nonferrous Metals (Smelting Part), 2013, 3: 4-7) proposed the use of adsorbents such as fly ash, activated carbon and bentonite to treat residual organic matter in manganese sulfate solution by physical adsorption. The COD removal rate is about 40.8%, which is relatively low, and the adsorption material is difficult to activate and has a large loss. In addition, although there are many deep oxidation treatment methods for removing organic impurities from solutions, due to the Mn in the sulfuric acid system 2+ It is easily oxidized to MnO2 precipitate, and oxidation technology is not suitable for removing organic impurities in manganese sulfate solution.

[0005] In order to solve the problem of effectively removing organic impurities in the existing manganese sulfate solution, the present invention provides a method for selectively removing organic impurities. Summary of the invention

[0006] The main purpose of the present invention is to provide a method for removing organic impurities in a manganese sulfate solution, so as to solve the problem that it is difficult to effectively remove organic impurities in the manganese sulfate solution in the prior art.

[0007] In order to achieve the above-mentioned object, according to one aspect of the present invention, a method for removing organic impurities from a manganese sulfate solution is provided, the method comprising: step S1, providing an organic solvent aerosol, mixing the organic solvent aerosol with a manganese sulfate solution to be purified in a negative pressure state, breaking the organic solvent aerosol into an organic solvent, and collecting the organic impurities in the manganese sulfate solution to be purified in the organic solvent to obtain a layered manganese sulfate aqueous solution and an organic phase in which the organic impurities are dissolved; step S2, separating the manganese sulfate aqueous solution and the organic phase to obtain a purified manganese sulfate aqueous solution and an organic phase to be purified.

[0008] Further, in step S1, the organic solvent aerosol is a microbubble organic solvent aerosol, and the diameter of the microbubbles is 0.001 to 100 μm; the gas in the organic solvent aerosol is a non-oxidizing gas, preferably including at least one of CO2, N2 or an inert gas; the organic solvent in the organic solvent aerosol is a non-polar or weakly polar organic solvent, and is insoluble in water or slightly soluble in water; the non-polar organic solvent is preferably at least one of benzene and its non-polar derivatives, carbon tetrachloride, carbon disulfide, alkane solvents, no, and imidazoline; the weakly polar solvent is preferably at least one of an ether or alkane solvent.

[0009] Furthermore, the organic solvent in the organic solvent aerosol is a mixed solvent of carbon tetrachloride, n-hexyl ether and pyrrolidone, and the mass ratio of the three is 1:(1~2):(1~2); or, the organic solvent in the solvent aerosol is a mixed solvent of hexane, toluene, N-methylpyrrolidone and kerosene, and the mass ratio of the four is 1:(1~2):1:(1~2); or, the organic solvent in the solvent aerosol is a mixed solvent of carbon disulfide and petroleum ether, and the mass ratio of the two is (1~2):1.

[0010] Furthermore, in step S1, the solvent aerosol is pressed into the manganese sulfate solution to be purified in a negative pressure state for mixing, the pressure of the solvent aerosol is 0.12-0.8 MPa, and the pressure of the manganese sulfate solution to be purified is 0.01-0.09 MPa.

[0011] Furthermore, in step S1, the solvent aerosol is mixed with the manganese sulfate solvent to be purified for 0.5 to 20 minutes at a temperature of -10 to 90°C.

[0012] Furthermore, in step S2, the manganese sulfate aqueous solution and the organic phase are separated by splitting.

[0013] Furthermore, step S2 also includes purification of the organic phase to be purified to obtain an organic solvent and organic matter, and the organic solvent is used to prepare an organic solvent aerosol.

[0014] Furthermore, the purification method is distillation.

[0015] Furthermore, step S2 also includes removing water from the purified manganese sulfate aqueous solution to obtain a manganese sulfate product.

[0016] Furthermore, the water is removed by drying.

[0017] Furthermore, in step S2, the purified aqueous solution of manganese sulfate is returned to step S1 to continue removing organic impurities.

[0018] Furthermore, in the manganese sulfate solution to be purified, Mn 2+ The content of organic impurities is 2-120g / L, COD cr The content is 0.2~10g / L and the pH is -1~11.

[0019] Furthermore, the manganese sulfate solution to be purified is derived from the manganese extraction leaching solution, the Mn-containing 2+ At least one of the wastewater or electrolytic manganese circulating liquid.

[0020] By applying the technical solution of the present application, the method for removing organic impurities from a manganese sulfate solution provided by the present application comprises mixing an organic solvent aerosol with a manganese sulfate solution to be purified in a negative pressure state, utilizing the high permeability and high solubility of the organic solvent aerosol to increase the probability of dissolving and contacting the organic impurities in the manganese sulfate solution to be purified with the organic solvent, and at the same time, the surface reaction activity of the organic solvent caused by the instantaneous embrittlement of the organic solvent aerosol under the influence of negative pressure is enhanced, thereby strengthening the competitive adsorption and dissolution ability of the organic solvent on the organic impurities in the aqueous phase solution, thereby effectively improving the removal efficiency of the organic impurities, and having a low metal loss rate, the method can be suitable for large-scale production, effectively reducing the removal cost of the organic impurities in the manganese sulfate solution to be purified, and has broad application prospects. DETAILED DESCRIPTION

[0021] 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 in conjunction with the embodiments.

[0022] As analyzed in the background technology of the present application, the existing methods for purifying manganese sulfate solutions all have the problem of being unable to effectively remove organic impurities in the manganese sulfate solution. In order to solve this problem, the present application provides a method for removing organic impurities in manganese sulfate solution.

[0023] In a typical embodiment of the present application, a method for removing organic impurities from a manganese sulfate solution is provided, the method comprising: step S1, providing an organic solvent aerosol, mixing the organic solvent aerosol with a manganese sulfate solution to be purified in a negative pressure state, the organic solvent aerosol breaking into an organic solvent, the organic impurities in the manganese sulfate solution to be purified are gathered in the organic solvent, and a layered manganese sulfate aqueous solution and an organic phase welded with organic impurities are obtained; step S2, separating the manganese sulfate aqueous solution and the organic phase to obtain a purified manganese sulfate aqueous solution and an organic phase to be purified.

[0024] In the present application, the manganese sulfate solution to be purified refers to an aqueous solution of manganese sulfate.

[0025] By applying the technical solution of the present application, the method for removing organic impurities from a manganese sulfate solution provided by the present application comprises mixing an organic solvent aerosol with a manganese sulfate solution to be purified in a negative pressure state, utilizing the high permeability and high solubility of the organic solvent aerosol to increase the probability of organic impurities in the manganese sulfate solution to be purified being dissolved and contacted with the organic solvent, and at the same time, the surface reaction activity of the organic solvent caused by instantaneous brittle fracture of the organic solvent aerosol under the influence of negative pressure is enhanced, thereby strengthening the competitive adsorption and dissolution ability of the organic solvent on the organic impurities in the aqueous phase solution, thereby effectively improving the removal efficiency of the organic impurities, and having a low metal loss rate, the method can be suitable for large-scale production, effectively reducing the removal cost of the organic impurities in the manganese sulfate solution to be purified, and has broad application prospects.

[0026] In the above step S1, during the process of mixing the organic solvent aerosol with the manganese sulfate solution to be purified in a negative pressure state, the organic solvent aerosol is rapidly exploded into an organic solvent under the influence of pressure. On the one hand, the surface of the aerosol is broken, which further increases the contact probability of the organic solvent with the organic impurities in the manganese sulfate solution to be purified. On the other hand, the aerosol fragmentation increases the surface quality of the organic solvent, further enhancing the ability of the organic solvent to compete with the aqueous phase of the manganese sulfate solution to be purified for the organic impurities in the solvent, making it easier for the organic impurities to be dissolved into the organic solvent. At the same time, since the organic solvent and the aqueous phase of the manganese sulfate solution to be purified have weak solubility, the organic phase of the organic solvent containing the organic impurities will move relative to each other and aggregate relative to each other, thereby promoting a stable aqueous phase of the manganese sulfate solution and an organic phase of the organic solvent containing the organic impurities, and then separating to obtain a purified aqueous manganese sulfate solution and an organic phase to be purified.

[0027] The specific type of organic impurities in the manganese sulfate solution to be purified is not particularly limited. From the perspective of improving removal efficiency, highly polar and difficult to degrade organic impurities are preferred.

[0028] The content of organic impurities in the manganese sulfate solution to be purified and the content of Mn 2+ The contents of Mn and Mn are not specifically limited. In order to further improve the removal efficiency of organic impurities, it is preferred that the manganese sulfate solution to be purified contains Mn 2+ The content of organic impurities is 2-120g / L, COD cr The content is 0.2~10g / L and the pH is -1~11.

[0029] The specific source of the manganese sulfate solution to be purified is not specifically limited, and any manganese sulfate solution to be purified containing organic impurities may be used, including but not limited to manganese extraction leaching solution, Mn-containing 2+ A mixed manganese sulfate solution to be purified is formed by any one or more of the wastewater or electrolytic manganese circulating liquid.

[0030] The organic solvent aerosol is prepared by an organic solvent through an aerosol generator, and is preferably a microbubble organic solvent aerosol, the diameter of the microbubble is 0.001-100 μm, which is more conducive to mixing with the manganese sulfate solution to be purified to improve the removal efficiency of organic impurities in the manganese sulfate solution to be purified.

[0031] In order to avoid the influence of oxidizing gas on the manganese sulfate solution to be purified, the gas in the organic solvent is preferably a non-oxidizing gas, and the non-oxidizing gas includes but is not limited to a mixed gas formed by any one or more of CO2, N2 or an inert gas. The inert gas includes but is not limited to helium and / or argon.

[0032] In order to further improve the removal efficiency of organic impurities by organic solvent aerosol, it is preferred that the organic solvent in the organic solvent aerosol is a non-polar or weakly polar organic solvent, and is insoluble or slightly soluble in water. Slightly soluble means that the solubility s of the organic solvent in 100g of water satisfies 0.01g<s<1g, and insoluble means that the solubility s of the organic solvent in 100g of water satisfies s≤0.01g.

[0033] Non-polar organic solvents include but are not limited to benzene and its non-polar derivatives, carbon tetrachloride, carbon disulfide, alkane solvents (such as n-hexane, cyclohexane, etc.), kerosene or any one or more mixed organic solvents of imidazoline; weak polar solvents include but are not limited to any one or more mixed organic solvents of ether solvents (such as diethyl ether, propyl ether, petroleum ether, etc.) or alkane solvents (such as N-methylpyrrolidone, 1-benzyl-2-pyrrolidone).

[0034] In some embodiments of the present application, when the manganese sulfate solution to be purified is derived from a leachate for manganese extraction, the organic solvent in the organic solvent aerosol is preferably a mixed solvent of carbon tetrachloride, n-hexyl ether and pyrrolidone, and the mass ratio of the three is 1:(1-2):(1-2), thereby being able to more effectively remove difficult-to-treat, highly polar high-molecular organic impurities in the manganese sulfate solution to be purified.

[0035] In other embodiments of the present application, when the manganese sulfate solution to be purified comes from a solution containing Mn 2+ When the wastewater is purified, the organic solvent in the solvent aerosol is preferably a mixed solvent of hexane, toluene, N-methylpyrrolidone and kerosene, and the mass ratio of the four is 1:(1-2):1:(1-2), which is more conducive to improving the removal efficiency of high molecular alcohols, benzene rings, esters, pyrroles and alkanes in the manganese sulfate solution to be purified.

[0036] In other embodiments of the present application, when the manganese sulfate solution to be purified comes from the electrolytic manganese circulating liquid, the organic solvent in the solvent aerosol is a mixed solvent of carbon disulfide and petroleum ether, and the mass ratio of the two is (1-2):1, which is more conducive to improving the removal efficiency of esters, carboxylic acids, amides and weakly polar and strongly polar organic impurities in the manganese sulfate solution to be purified.

[0037] In the above step S1, in order to improve the mixing efficiency of the solvent aerosol and the sulfuric acid solution in a negative pressure state, the solvent aerosol is preferably pressed into the manganese sulfate solution to be purified in a negative pressure state for mixing, and the pressure of the solvent aerosol is 0.12-0.8 MPa, and the pressure of the manganese sulfate solution to be purified is 0.01-0.09 MPa.

[0038] In order to further improve the removal efficiency of organic impurities, in step S1, the solvent aerosol and the manganese sulfate solvent are preferably mixed for 0.5 to 20 minutes at a temperature of -10 to 90°C.

[0039] Typically but not limiting, in step S1, the pressure of the solvent aerosol is 0.12MPa, 0.15MPa, 0.18MPa, 0.2MPa, 0.3MPa, 0.4MPa, 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa or a range consisting of any two values; the pressure of the manganese sulfate solution to be purified is -0.09MPa, -0.08MPa, -0.07MPa, -0.06MPa, -0.05MPa, -0.04MPa, -0.06MPa, The mixing time of the solvent aerosol and the manganese sulfate solution to be purified is, for example, 0.5 min, 0.1 min, 2 min, 5 min, 8 min, 10 min, 15 min, 18 min, 20 min or a range consisting of two values; the mixing temperature is, for example, -10°C, -5°C, 0°C, 5°C, 10°C, 20°C, 50°C, 80°C, 90°C or a range consisting of two values.

[0040] In order to further reduce the cost of removing organic impurities in the manganese sulfate solution to be purified, it is preferred that in step S2, the aqueous manganese sulfate solution and the organic phase are separated by splitting, which effectively simplifies the separation process and is more conducive to reducing costs.

[0041] In order to further improve the utilization efficiency of energy, preferably step S2 also includes purification of the organic phase to be purified to obtain an organic solvent and organic matter, and the obtained organic solvent is used to prepare an organic solvent aerosol, further reducing the cost of removing organic impurities.

[0042] In some embodiments of the present application, preferably step S2 further comprises removing the aqueous phase from the purified aqueous solution of manganese sulfate to obtain a manganese sulfate product, which is more conducive to storage and transportation.

[0043] In order to further reduce the cost of removing the water phase, the water phase is preferably removed by drying.

[0044] In order to further improve the removal efficiency of organic impurities in the manganese sulfate solution to be purified and further reduce the content of organic impurities in the purified manganese sulfate solution, it is preferred that the purified aqueous solution of manganese sulfate obtained in step S2 is returned to step S1 to continue the removal of organic impurities to meet the quality requirements of the manganese sulfate product.

[0045] In some embodiments of the present application, the method for removing organic impurities from the manganese sulfate solution to be purified is carried out according to the following steps:

[0046] (1) selecting a non-polar organic solvent and preparing an organic solvent aerosol with a diameter of 0.001 to 100 μm by using a microbubble aerosol generator;

[0047] (2) placing the manganese sulfate solution to be purified in a reactor, and evacuating the manganese sulfate solution to be purified so that it is in a negative pressure state, with a pressure of 0.01 to 0.09 MPa;

[0048] (3) pressing the organic solvent aerosol into the manganese sulfate solution to be purified in a negative pressure state, the pressure of the solvent aerosol is 0.12 to 0.6 Ma, and mixing at a temperature of 10 to 40° C. for 4 to 15 minutes to obtain a stratified manganese sulfate aqueous phase solution and an organic phase containing dissolved organic impurities;

[0049] (4) separating the manganese sulfate aqueous solution and the organic phase by splitting to obtain a purified manganese sulfate aqueous solution and an organic phase to be purified;

[0050] (5) distilling the organic phase to be purified, collecting the organic solvent, and returning the organic solvent to step (1) to continue preparing the organic solvent aerosol;

[0051] (6) removing water from the purified manganese sulfate aqueous solution to obtain a manganese sulfate product.

[0052] The beneficial effects of the present application are further illustrated below in combination with embodiments and comparative examples.

[0053] Example 1

[0054] This embodiment provides a method for removing organic impurities from a manganese sulfate solution. The manganese sulfate solution to be purified is prepared by using coking wastewater as a pyrolusite reducing agent to reduce and leach pyrolusite in a dilute sulfuric acid solution to obtain a manganese extraction leaching solution, wherein Mn 2+ 46.2g / L, COD cr It is 1.89g / L, pH 0.5, and the organic impurities are mainly highly polar polymers.

[0055] The specific method includes the following steps:

[0056] (1) Carbon tetrachloride, n-hexyl ether, and pyrrolidone are mixed in a mass ratio of 1:1:2 to form a uniform organic solvent, which is then placed in an aerosol (microbubble) generator with N2 as the medium to prepare a microbubble organic solvent aerosol with a diameter of 0.01 to 0.1 μm.

[0057] (2) placing the manganese sulfate solution to be purified in a reactor, and evacuating the manganese sulfate solution to be purified to a negative pressure state of 0.01 MPa;

[0058] (3) continuously pressing the organic solvent aerosol into the manganese sulfate solution to be purified in a negative pressure state at a pressure of 0.5 MPa, mixing at 30° C. for 4 minutes, and standing to obtain a hexyl ether organic phase containing organic impurities, a manganese sulfate aqueous solution, and a carbon tetrachloride-pyrrolidone organic phase containing organic impurities, which are stacked in sequence;

[0059] (4) Separating the sequentially stacked hexyl ether organic phase containing dissolved organic impurities, the manganese sulfate aqueous solution and the carbon tetrachloride-pyrrolidone organic phase containing dissolved organic impurities by splitting to obtain a once purified manganese sulfate aqueous solution, a hexyl ether organic phase containing dissolved organic impurities and a carbon tetrachloride-pyrrolidone organic phase containing dissolved organic impurities, a hexyl ether organic phase containing dissolved organic impurities and a carbon tetrachloride-pyrrolidone organic phase containing dissolved organic impurities, and distilling and recovering the hexyl ether, carbon tetrachloride and pyrrolidone respectively.

[0060] Example 2

[0061] The difference between this embodiment and embodiment 1 is that in step (2), the pressure of the manganese sulfate solution to be purified is 0.09 MPa, and in step (3), the organic solvent aerosol is continuously pressed into the manganese sulfate solution to be purified in a negative pressure state at a pressure of 0.6 MPa and mixed at -10°C for 20 minutes.

[0062] Example 3

[0063] The difference between this embodiment and embodiment 1 is that in step (3), the organic solvent aerosol is continuously pressed into the manganese sulfate solution to be purified in a negative pressure state at a pressure of 0.12 MPa and mixed at 90° C. for 0.5 min.

[0064] Example 4

[0065] The difference between this embodiment and embodiment 1 is that in step (2), the pressure of the manganese sulfate solution to be purified is 0.005 MPa.

[0066] Example 5

[0067] The difference between this embodiment and embodiment 1 is that in step (2), the pressure of the manganese sulfate solution to be purified is 0.095 MPa.

[0068] Example 6

[0069] This embodiment provides a method for removing organic impurities from a manganese sulfate solution. The manganese sulfate solution to be purified is a pharmaceutical waste residue from a Chinese medicine factory. The wastewater is used as a pyrolusite reducing agent. The original leachate obtained by reducing and leaching manganese smelting slag in a dilute sulfuric acid solution is Mn 2+ 16.4g / L, COD crThe concentration of organic impurities was 9.7 g / L, pH 2.5, and the main organic impurities were high molecular alcohols, benzene rings, esters, pyrroles and alkanes.

[0070] The specific method includes the following steps:

[0071] (1) Hexane, toluene, N-methylpyrrolidone, and kerosene are prepared into a uniformly mixed organic solvent in a mass ratio of 1:2:1:2, and then the mixed organic solvent is placed in an aerosol (microbubble) generator with N2 as a medium to prepare a microbubble organic solvent aerosol with a diameter of 0.1 to 100 μm.

[0072] (2) placing the manganese sulfate solution to be purified in a reactor, and evacuating the manganese sulfate solution to be purified to a negative pressure state of 0.05 MPa;

[0073] (3) continuously pressing the organic solvent aerosol into the manganese sulfate solution to be purified in a negative pressure state at a pressure of 0.8 MPa, mixing at room temperature for 6 minutes, and standing to obtain a toluene and kerosene organic phase containing organic impurities, a manganese sulfate aqueous solution, and a hexane-pyrrolidone organic phase containing organic impurities that are sequentially stacked;

[0074] (4) Separating the sequentially stacked toluene and kerosene organic phases, the manganese sulfate aqueous solution, and the hexane-pyrrolidone organic phases by splitting to obtain a once-purified manganese sulfate aqueous solution, the toluene and kerosene organic phases, and the hexane-pyrrolidone organic phases; and distilling the toluene and kerosene organic phases and the hexane-pyrrolidone organic phases to recover toluene, kerosene, hexane, and N-methylpyrrolidone.

[0075] (5) Returning the once purified manganese sulfate aqueous solution to step (2), and performing a second impurity removal according to steps (2) to (5) to obtain a second purified manganese sulfate aqueous solution.

[0076] Example 7

[0077] This embodiment provides a method for removing organic impurities from a manganese sulfate solution. The manganese sulfate solution to be purified is prepared from a waste battery containing Mn electrodes, and the manganese sulfate and multi-metal ions are leached in a dilute sulfuric acid solution by a strong catalytic oxidation full wet method to obtain an original leachate. 2+ 16.4g / L, COD cr The concentration of impurities in the electrolyte is 9.7 g / L, pH is 2.5, and the organic impurities are mainly esters, carboxylic acids, amides and other weak and strong polar impurities remaining after oxidation of the battery electrolyte.

[0078] The specific method includes the following steps:

[0079] (1) Carbon disulfide and petroleum ether are prepared into a mixed organic solvent in a mass ratio of 2:1, and then the mixed organic solvent is placed in an aerosol (microbubble) generator with CO2 as the medium to prepare a microbubble organic solvent aerosol with a diameter of 0.001 to 0.1 μm.

[0080] (2) placing the manganese sulfate solution to be purified in a reactor, and evacuating the manganese sulfate solution to be purified to a negative pressure state of 0.03 MPa;

[0081] (3) continuously pressing the organic solvent aerosol into the manganese sulfate solution to be purified in a negative pressure state at a pressure of 0.6 MPa, mixing at -5°C for 10 minutes, and standing to obtain a petroleum ether organic phase in which organic impurities are dissolved, a manganese sulfate aqueous solution, and a carbon disulfide organic phase in which organic impurities are dissolved, which are sequentially stacked;

[0082] (4) Separating the petroleum ether organic phase containing dissolved organic impurities, the manganese sulfate aqueous solution, and the carbon disulfide organic phase containing dissolved organic impurities by splitting to obtain a once-purified manganese sulfate aqueous solution, the petroleum ether organic phase containing dissolved organic impurities, and the carbon disulfide organic phase containing dissolved organic impurities; and distilling the petroleum ether organic phase containing dissolved organic impurities and the carbon disulfide organic phase containing dissolved organic impurities to recover the petroleum ether and carbon disulfide.

[0083] Comparative Example 1

[0084] The difference between this comparative example and Example 1 is that step (2) is not performed, and step (3) is performed directly, that is, the organic solvent aerosol is directly poured into the manganese sulfate solution to be purified for mixing.

[0085] Test example

[0086] The content of organic impurities in the purified manganese sulfate aqueous solution was detected, and the primary operation impurity removal rate and the optional secondary operation impurity removal rate were calculated. The results are shown in Table 1 below.

[0087] Table 1

[0088]

[0089]

[0090] Note: The “——” above means that no secondary impurity removal was performed.

[0091] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0092] By applying the technical solution of the present application, the method for removing organic impurities from a manganese sulfate solution provided by the present application comprises mixing an organic solvent aerosol with a manganese sulfate solution to be purified in a negative pressure state, utilizing the high permeability and high solubility of the organic solvent aerosol to increase the probability of dissolving and contacting the organic impurities in the manganese sulfate solution to be purified with the organic solvent, and at the same time, the surface reaction activity of the organic solvent caused by the instantaneous embrittlement of the organic solvent aerosol under the influence of negative pressure is enhanced, thereby strengthening the competitive adsorption and dissolution ability of the organic solvent on the organic impurities in the aqueous phase solution, thereby effectively improving the removal efficiency of the organic impurities, and having a low metal loss rate, the method can be suitable for large-scale production, effectively reducing the removal cost of the organic impurities in the manganese sulfate solution to be purified, and has broad application prospects.

[0093] The above description is only a preferred embodiment of the present invention and is 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 method for removing organic impurities from a manganese sulfate solution, It is characterized in that The method comprises: Step S1, providing an organic solvent aerosol, mixing the organic solvent aerosol with a manganese sulfate solution to be purified in a negative pressure state, the organic solvent aerosol is broken into an organic solvent, and organic impurities in the manganese sulfate solution to be purified are gathered in the organic solvent, thereby obtaining a stratified manganese sulfate aqueous phase solution and an organic phase in which the organic impurities are dissolved; Step S2, separating the manganese sulfate aqueous solution and the organic phase to obtain a purified manganese sulfate aqueous solution and an organic phase to be purified; Wherein, in step S1, the solvent aerosol is pressed into the manganese sulfate solution to be purified in a negative pressure state for mixing, the pressure of the solvent aerosol is 0.12-0.8 MPa, and the pressure of the manganese sulfate solution to be purified is 0.01-0.09 MPa.

2. The method according to claim 1, It is characterized in that In step S1, the organic solvent aerosol is a microbubble organic solvent aerosol, and the diameter of the microbubbles is 0.001-100 μm; The gas in the organic solvent aerosol is a non-oxidizing gas; The organic solvent in the organic solvent aerosol is a non-polar or weakly polar organic solvent and is insoluble in water or slightly soluble in water.

3. The method according to claim 2, It is characterized in that The gas in the organic solvent aerosol includes CO 2 or at least one of an inert gas.

4. The method according to claim 2, It is characterized in that The organic solvent is at least one of benzene, carbon tetrachloride, carbon disulfide, n-hexane, cyclohexane, kerosene, imidazoline, ethyl ether, propyl ether, petroleum ether, N-methylpyrrolidone or 1-benzyl-2-pyrrolidone.

5. The method according to claim 2, It is characterized in that The organic solvent in the organic solvent aerosol is a mixed solvent of carbon tetrachloride, n-hexyl ether and pyrrolidone, and the mass ratio of the three is 1:(1~2):(1~2); or, the organic solvent in the solvent aerosol is a mixed solvent of hexane, toluene, N-methylpyrrolidone and kerosene, and the mass ratio of the four is 1:(1~2):1:(1~2); or, the organic solvent in the solvent aerosol is a mixed solvent of carbon disulfide and petroleum ether, and the mass ratio of the two is (1~2):

1.

6. The method according to claim 1, It is characterized in that In the step S1, the solvent aerosol and the manganese sulfate solution to be purified are mixed for 0.5 to 20 minutes at a temperature of -10 to 90°C.

7. The method according to any one of claims 1 to 6, It is characterized in that In step S2, the manganese sulfate aqueous solution and the organic phase are separated by splitting.

8. The method according to any one of claims 1 to 6, It is characterized in that The step S2 also includes purifying the organic phase to be purified to obtain an organic solvent and organic matter, and the organic solvent is used to prepare an organic solvent aerosol.

9. The method according to claim 8, It is characterized in that The purification method is distillation.

10. The method according to any one of claims 1 to 6, It is characterized in that The step S2 further comprises removing water from the purified aqueous solution of manganese sulfate to obtain a manganese sulfate product.

11. The method according to claim 10, It is characterized in that The water is removed by drying.

12. The method according to any one of claims 1 to 6, It is characterized in that In step S2, the purified aqueous solution of manganese sulfate is returned to step S1 to continue removing the organic impurities.

13. The method according to any one of claims 1 to 6, It is characterized in that In the manganese sulfate solution to be purified, Mn 2+ The content of organic impurities is 2~120g / L, COD cr The content is 0.2~10g / L and the pH is 0.5~11.

14. The method according to claim 13, It is characterized in that The manganese sulfate solution to be purified is derived from a manganese extraction leaching solution containing Mn 2+ At least one of the wastewater or electrolytic manganese circulating liquid.

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