Method for extracting high-purity manganese carbonate by using electrolytic manganese anolyte

Abstract

The present application relates to the field of high-purity manganese-based material manufacturing, and particularly relates to a method for extracting high-purity manganese carbonate by using electrolytic manganese anode liquid. The method comprises the following steps: S1, adding ammonium fluoride into the electrolytic manganese anode liquid, heating and stirring, then adding modified activated carbon, heating and stirring, pressure filtration, and collecting the filtrate 1; S2, mixing the eutectic solvent with n-hexane, stirring, obtaining an organic phase, mixing the organic phase with the filtrate 1, stirring, centrifugal separation, obtaining an extraction phase and a raffinate; S3, washing the extraction phase obtained in step S2 with sulfuric acid, using sulfuric acid solution for back extraction according to the flow ratio of the organic phase to the aqueous phase being 6-10:1, obtaining a manganese-rich solution; S4, adding the manganese-rich solution into the ammonium bicarbonate solution, adjusting the PH, heating and stirring, standing, pressure filtration, obtaining a filter cake a and a filtrate 2, and drying the filter cake a to obtain manganese carbonate. The manganese carbonate product prepared by the method has high purity, and has the advantages of convenient operation, no harm to the environment, high efficiency, good selectivity and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-purity manganese-based material manufacturing, and particularly relates to a method for extracting high-purity manganese carbonate from electrolytic manganese anolyte. BACKGROUND

[0002] In the production process of the electrolytic manganese industry, a large amount of anolyte is produced, which contains a large amount of manganese ion resources, but is also mixed with magnesium ions, calcium ions and sulfate ions and other impurities. If the anolyte is directly discharged, not only will the manganese resources be lost, causing great waste of resources, but also the various impurities in the anolyte that has not been properly treated will cause serious pollution to the ecological environment elements such as soil and water, and destroy the ecological balance.

[0003] From the existing treatment methods, the traditional method has obvious limitations in the purification of manganese ions in the anolyte, and it is difficult to efficiently convert it into high-purity manganese carbonate products with high added value, which cannot meet the current market demand for high-purity manganese carbonate. Therefore, developing a preparation method that is efficient and environmentally friendly can accurately extract high-purity manganese carbonate from electrolytic manganese anolyte, which helps to fully exploit the potential value of manganese resources and avoid their being discarded. SUMMARY

[0004] In view of the shortcomings of the prior art, the present application provides a method for extracting high-purity manganese carbonate from electrolytic manganese anolyte, which has the advantages of high purity, easy operation, high efficiency and good selectivity.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is:

[0006] A method for extracting high-purity manganese carbonate from electrolytic manganese anolyte, comprising the following steps:

[0007] S1, taking the electrolytic manganese anolyte to be treated, adjusting the pH to 6-6.5, adding ammonium fluoride to the electrolytic manganese anolyte after adjusting the pH, heating and stirring for 2-3h, then adding modified activated carbon, heating and stirring for 2-3h, pressure filtration, and collecting the filtrate 1;

[0008] S2, mixing the eutectic solvent with a mass ratio of 1-2:5-7 with n-hexane, stirring for 8-12min, to obtain an organic phase, mixing the organic phase with the filtrate 1, heating and stirring for 1-2h, centrifugal separation, to obtain an extraction phase and a raffinate;

[0009] S3, washing the extraction phase obtained in step S2 with sulfuric acid, and using a 4-6mol / L sulfuric acid solution to perform back extraction according to a flow ratio of the organic phase to the aqueous phase of 6-10:1, to obtain a manganese-rich solution;

[0010] S4, while stirring, the manganese-rich solution is added to the ammonium bicarbonate solution, the PH is adjusted to 6-7, heated and stirred for 8-12h, then stand for 1-2h, filter pressing, to get filter cake a and filtrate 2, filter cake a is washed with pure water 3-5 times, dried to get manganese carbonate.

[0011] Preferably, the mass ratio of ammonium fluoride, modified activated carbon and electrolytic manganese anode solution in step S1 is 4-6:1-2:40-60.

[0012] Preferably, the modified activated carbon is prepared by the following method:

[0013] A1, the activated carbon and iron nitrate nonahydrate are added to a high-pressure reaction kettle, then deionized water and ascorbic acid are added, stirred for 10-15min, then heated and reacted for 10-15h, cooled to room temperature, filtered, washed, dried, and calcined to obtain a composite activated carbon;

[0014] A2, the composite activated carbon is dispersed in N,N-dimethylformamide, oxalic acid is added, heated and stirred for 20-30min, then 3-chloro-2-hydroxypropane sulfonic acid sodium and triethylamine are added, heated and stirred for 3-5h, filtered, washed, and dried to obtain the modified activated carbon.

[0015] Preferably, in step A1, the mass fraction of activated carbon, iron nitrate nonahydrate, ascorbic acid and deionized water is 15-25 parts, 3-5 parts, 0.05-0.1 parts and 60-80 parts respectively.

[0016] Preferably, in step A2, the mass ratio of composite activated carbon, oxalic acid, 3-chloro-2-hydroxypropane sulfonic acid sodium, triethylamine and N,N-dimethylformamide is 8-12:1-2:0.8-1.2:0.05-0.1:50-60.

[0017] Preferably, the eutectic solvent in step S2 is prepared by stirring benzyltrimethylammonium chloride, modified citric acid and dipentaerythritol in a molar ratio of 2-4:1-3:1.2-1.8 at 70-90℃ for 3-5h.

[0018] Preferably, the modified citric acid is prepared by the following method:

[0019] Mix citric acid, imino oxalic acid and deionized water, stir for 10-15min, then add trifluoromethanesulfonic acid, heat and stir for 4-6h, evaporate the solvent to obtain modified citric acid; wherein the mass ratio of citric acid, imino oxalic acid, trifluoromethanesulfonic acid and deionized water is 8-12:2-4:0.2-0.3:60-70.

[0020] Preferably, the mass ratio of organic phase to filtrate 1 in step S2 is 3-5:5-8.

[0021] Preferably, the mass ratio of the manganese-rich solution and the ammonium bicarbonate solution in the step S4 is 5-8:9-12.

[0022] Preferably, the filtrate 2 in the step S4 also needs to be treated by a fluorine removal agent.

[0023] The present application has the following beneficial effects:

[0024] The present application has the following beneficial effects:

[0025] The present application has the following beneficial effects:

[0026] The application constructs an extraction process of high-purity manganese carbonate product, wherein the introduced modified activated carbon can effectively adsorb calcium fluoride and other precipitates, effectively remove calcium ions and other impurities in the electrolytic manganese anolyte, and further introduce an environmentally friendly eutectic solvent which is simple and convenient to prepare; the eutectic solvent can efficiently realize the separation of manganese, effectively promote the smooth progress of the entire extraction process; and the obtained filtrate is subjected to defluorination treatment, so as to ensure that the entire production process is harmless to the environment. The extraction method has the advantages of simplified process, efficient operation mode, effective separation and removal of impurities, greatly improved production efficiency of high-purity manganese carbonate product, and effectively guaranteed product quality, so that the product has more advantages in market competition. DETAILED DESCRIPTION

[0027] The materials and reagents used in the application can be obtained from commercial channels unless otherwise specified.

[0028] Ammonium fluoride was purchased from Langfang Pengcai Fine Chemical Co., Ltd., and was analytical pure AR with a content of 96%; activated carbon was purchased from Ningxia Shengmeihua Rui Activated Carbon Manufacturing Co., Ltd., and had a mesh size of 100 mesh; citric acid was purchased from Wujian City Xinmao Fine Chemical Co., Ltd., and was industrial grade; benzyltrimethylammonium chloride was purchased from Shandong Xinghai Chemical Co., Ltd.; iminodiacetic acid was purchased from Shandong Yinglang Chemical Co., Ltd., and had a density of 1.436 g / cm 3 ; trifluoromethanesulfonic acid was purchased from Wuhan Lananbai Pharmaceutical Chemical Co., Ltd.; dipentaerythritol was purchased from Shandong Suihua Biological Technology Co., Ltd., and had a content of 99%; HPF3500 resin was purchased from Jiangsu Haipu Functional Materials Co., Ltd.; pentaerythritol was purchased from Anhui Jinyueguan New Material Technology Co., Ltd.

[0029] Example 1

[0030] A method for extracting high-purity manganese carbonate from electrolytic manganese anolyte, comprising the following steps:

[0031] S1, taking the electrolytic manganese anolyte to be treated, adjusting the pH to 6, adding ammonium fluoride to the electrolytic manganese anolyte after adjusting the pH, stirring at 50℃ and 100rpm for 3h, then adding modified activated carbon, stirring at 50℃ and 100rpm for 3h, pressure filtration, and collecting the filtrate 1; wherein the pressure filtration conditions are: the filtration pressure is 0.2MPa, and the filtration time is 5min; the mass ratio of ammonium fluoride, modified activated carbon and electrolytic manganese anolyte is 4:1:40;

[0032] S2, the eutectic solvent with a mass ratio of 1:5 was mixed with n-hexane, stirred at 80 rpm for 8 min to prepare an organic phase, the organic phase was mixed with the filtrate 1, stirred at 60 DEG C, 100 rpm for 2 h, centrifuged at 8000 rpm for 6 min to obtain an extraction phase and a raffinate; wherein the mass ratio of the organic phase to the filtrate 1 is 3:5;

[0033] S3, the extraction phase obtained in step S2 was washed with 1.5 mol / L sulfuric acid for 15 min, and back-extracted with 4 mol / L sulfuric acid solution according to the flow ratio of organic phase to aqueous phase of 6:1 to obtain a manganese-rich solution;

[0034] S4, the manganese-rich solution was added to the ammonium bicarbonate solution while stirring, the PH was adjusted to 6, and then stirred at 50 DEG C, 100 rpm for 8 h, and then placed for 1 h, and then filtered to obtain a filter cake a and a filtrate 2, the filter cake a was washed with pure water for 3 times, and then dried at 80 DEG C for 3 h to obtain manganese carbonate; wherein the mass ratio of the manganese-rich solution to the ammonium bicarbonate solution is 5:9, and the mass fraction of the ammonium bicarbonate solution is 25%.

[0035] The modified activated carbon was prepared by the following method:

[0036] A1, the activated carbon and iron nitrate nonahydrate were added to a high-pressure reaction kettle, deionized water and ascorbic acid were added, stirred at 150 rpm for 10 min, then stirred at 60 DEG C, 100 rpm for 10 h, cooled to room temperature, filtered, washed with deionized water for 3 times, dried at 70 DEG C for 3 h, heated to 600 DEG C under nitrogen atmosphere, and heated for 8 h to obtain a composite activated carbon; wherein, according to mass parts: activated carbon 15 parts, iron nitrate nonahydrate 3 parts, ascorbic acid 0.05 parts, deionized water 60 parts;

[0037] A2, the composite activated carbon was dispersed in N,N-dimethylformamide, oxalic acid was added, stirred at 60 DEG C, 100 rpm for 20 min, then 3-chloro-2-hydroxypropane sulfonic acid sodium and triethylamine were added, stirred at 60 DEG C, 100 rpm for 3 h, filtered, washed with deionized water for 3 times, and dried at 70 DEG C for 3 h to obtain a modified activated carbon; wherein, the mass ratio of the composite activated carbon, oxalic acid, 3-chloro-2-hydroxypropane sulfonic acid sodium, triethylamine and N,N-dimethylformamide is 8:1:0.8:0.05:50.

[0038] The eutectic solvent was prepared by stirring benzyltrimethylammonium chloride, modified citric acid and dipentaerythritol at a molar ratio of 2:1:1.2 at 70 DEG C for 3 h.

[0039] The modified citric acid was prepared by the following method:

[0040] Mix citric acid, iminodiacetic acid and deionized water, stir for 10 min, then add trifluoromethanesulfonic acid, stir at 60℃, 100 rpm for 4h, evaporate the solvent to obtain modified citric acid; wherein the mass ratio of citric acid, iminodiacetic acid, trifluoromethanesulfonic acid and deionized water is 8:2:0.2:60.

[0041] The filtrate 2 also needs to be treated by a defluorination process, which specifically includes:

[0042] A1, add a defluorination agent to the filtrate 2, stir for 15 min, adjust the pH to 6.5, and then stir for 10 min to obtain a mixed solution; wherein when the concentration of fluorine atoms in the filtrate 2 is <5ppm, the ratio of the defluorination agent to the filtrate 2 is 1L:0.9m 3 ; when 5ppm < concentration of fluorine atoms < 20ppm, the ratio of the defluorination agent to the filtrate 2 is 1.5L:0.9m 3 , and the defluorination agent is HPF3500 resin;

[0043] A2, add anionic polyacrylamide to the mixed solution, stir for 20 min, and stand for 1h to obtain supernatant and sediment, filter the sediment to obtain filter cake b and filtrate 3; wherein the mass ratio of anionic polyacrylamide to mixed solution is 5:12.

[0044] Example 2

[0045] A method for extracting high-purity manganese carbonate from electrolytic manganese anolyte, comprising the following steps:

[0046] S1, take the electrolytic manganese anolyte to be treated, adjust the pH to 6.5, add ammonium fluoride to the electrolytic manganese anolyte after adjusting the pH, stir at 70℃, 200rpm for 2h, then add modified activated carbon, stir at 70℃, 200rpm for 2h, filter, and collect the filtrate 1; wherein the filter conditions are: the filter pressure is 0.25MPa, and the filter time is 8min; the mass ratio of ammonium fluoride, modified activated carbon and electrolytic manganese anolyte is 6:2:60;

[0047] S2, mix the eutectic solvent and n-hexane with a mass ratio of 2:7, stir at 120rpm for 12min to prepare an organic phase, mix the organic phase with the filtrate 1, stir at 70℃, 200rpm for 1h, and centrifuge at 10000rpm for 4min to obtain an extraction phase and a raffinate;

[0048] S3, wash the extraction phase obtained in step S2 with 3mol / L sulfuric acid for 25min, and use 6mol / L sulfuric acid solution to back-extract according to the flow ratio of organic phase to water phase of 10:1 to obtain a manganese-rich solution;

[0049] S4, the manganese-rich solution is added to the ammonium bicarbonate solution while stirring, the PH is adjusted to 7, stirring is carried out at 60℃ and 200rpm for 12h, then standing for 2h, pressure filtration is carried out, a filter cake a and a filtrate 2 are obtained, the filter cake a is washed with pure water for 5 times, drying is carried out at 90℃ for 5h, and manganese carbonate is obtained; wherein the mass ratio of the manganese-rich solution and the ammonium bicarbonate solution is 8:12, and the mass fraction of the ammonium bicarbonate solution is 40%.

[0050] The modified activated carbon is prepared by the following method:

[0051] A1, the activated carbon and the iron nitrate nonahydrate are added to a high-pressure reaction kettle, then the deionized water and the ascorbic acid are added, stirring is carried out at 200rpm for 15min, then stirring is carried out at 70℃ and 200rpm for 15h, after cooling to room temperature, filtration is carried out, washing is carried out with deionized water for 5 times, drying is carried out at 80℃ for 5h, heating is carried out to 800℃ under nitrogen atmosphere, and heating is carried out for 5h, and the composite activated carbon is obtained; wherein, according to mass parts: the activated carbon is 25 parts, the iron nitrate nonahydrate is 5 parts, the ascorbic acid is 0.1 part, and the deionized water is 80 parts;

[0052] A2, the composite activated carbon is dispersed in N,N-dimethylformamide, the oxalic acid is added, stirring is carried out at 70℃ and 200rpm for 30min, then the 3-chloro-2-hydroxypropane sulfonic acid sodium and the triethylamine are added, stirring is carried out at 70℃ and 200rpm for 5h, filtration is carried out, washing is carried out with deionized water for 5 times, drying is carried out at 80℃ for 5h, and the modified activated carbon is obtained; wherein, the mass ratio of the composite activated carbon, the oxalic acid, the 3-chloro-2-hydroxypropane sulfonic acid sodium, the triethylamine and the N,N-dimethylformamide is 12:2:1.2:0.1:60.

[0053] The eutectic solvent is prepared by stirring benzyltrimethylammonium chloride, modified citric acid and dipentaerythritol in a molar ratio of 4:3:1.8 at 90℃ for 5h.

[0054] The modified citric acid is prepared by the following method:

[0055] The citric acid, imino oxalic acid and deionized water are mixed, stirring is carried out for 15min, then trifluoromethanesulfonic acid is added, stirring is carried out at 70℃ and 200rpm for 6h, and the solvent is removed by evaporation, and the modified citric acid is obtained; wherein, the mass ratio of the citric acid, the imino oxalic acid, the trifluoromethanesulfonic acid and the deionized water is 12:4:0.3:70.

[0056] The filtrate 2 also needs to be treated by a fluorine removal process, which specifically includes:

[0057] A1, add fluoride removal agent to the filtrate 2, stir for 35 min, adjust the PH to 7.0, and stir for another 15 min to obtain a mixed solution; wherein, when the concentration of fluorine atoms in the filtrate 2 is <5ppm, the ratio of fluoride removal agent to filtrate 2 is 1L:1.1m 3 ; when 5ppm < concentration of fluorine atoms in the filtrate 2 < 20ppm, the ratio of fluoride removal agent to filtrate 2 is 1.5L:1.1m 3 , the fluoride removal agent is HPF3500 type resin;

[0058] A2, add anionic polyacrylamide to the mixed solution, stir for 30 min, stand for 2h to obtain supernatant and precipitate, filter the precipitate to obtain filter cake b and filtrate 3; wherein, the mass ratio of anionic polyacrylamide to mixed solution is 8:15.

[0059] Example 3

[0060] A method for extracting high-purity manganese carbonate from electrolytic manganese anolyte, comprising the following steps:

[0061] S1, take the electrolytic manganese anolyte to be treated, adjust the PH to 6.5, add ammonium fluoride to the electrolytic manganese anolyte after adjusting the PH, stir at 60℃ and 150rpm for 2.5h, then add modified activated carbon, stir at 60℃ and 150rpm for 2.5h, filter, and collect the filtrate 1; wherein, the filter conditions are: the filter pressure is 0.25MPa, and the filter time is 6min; the mass ratio of ammonium fluoride, modified activated carbon and electrolytic manganese anolyte is 5:1.5:50;

[0062] S2, mix the eutectic solvent with n-hexane at a mass ratio of 1.5:6, stir at 100rpm for 10min to prepare an organic phase, mix the organic phase with the filtrate 1, stir at 65℃ and 150rpm for 1.5h, and centrifuge at 9000rpm for 5min to obtain an extraction phase and a raffinate;

[0063] S3, wash the extraction phase obtained in step S2 with 2mol / L sulfuric acid for 20min, and back extract with 5mol / L sulfuric acid solution according to the flow ratio of organic phase to water phase of 8:1 to obtain a manganese-rich solution;

[0064] S4, add the manganese-rich solution to the ammonium bicarbonate solution while stirring, adjust the PH to 6.5, stir at 55℃ and 150rpm for 10h, then stand for 1.5h, filter to obtain filter cake a and filtrate 2, wash the filter cake a with pure water 4 times, and dry at 85℃ for 4h to obtain manganese carbonate; wherein, the mass ratio of manganese-rich solution to ammonium bicarbonate solution is 6:10, and the mass fraction of ammonium bicarbonate solution is 30%.

[0065] The modified activated carbon is prepared by the following method:

[0066] A1, the activated carbon and iron nitrate nonahydrate are added into a high-pressure reaction kettle, then deionized water and ascorbic acid are added, stirred at 180 rpm for 13 min, then stirred at 150 rpm for 13 h at 65℃, cooled to room temperature, filtered, washed with deionized water for 4 times, dried at 75℃ for 4 h, heated to 700℃ under nitrogen atmosphere, heated for 6 h, to obtain the composite activated carbon; wherein, by mass fraction: activated carbon 20 parts, iron nitrate nonahydrate 4 parts, ascorbic acid 0.08 parts, deionized water 70 parts;

[0067] A2, the composite activated carbon is dispersed in N,N-dimethylformamide, oxalic acid is added, stirred at 65℃, 150 rpm for 25 min, then 3-chloro-2-hydroxypropane sulfonic acid sodium and triethylamine are added, stirred at 65℃, 150 rpm for 4 h, filtered, washed with deionized water for 4 times, dried at 75℃ for 4 h, to obtain the modified activated carbon; wherein, the mass ratio of the composite activated carbon, oxalic acid, 3-chloro-2-hydroxypropane sulfonic acid sodium, triethylamine and N,N-dimethylformamide is 10:1.5:1:0.08:55.

[0068] The eutectic solvent is prepared by stirring benzyltrimethylammonium chloride, modified citric acid and dipentaerythritol at a molar ratio of 3:2:1.5 at 80℃ for 4 h.

[0069] The modified citric acid is prepared by the following method:

[0070] The citric acid, imino oxalic acid and deionized water are mixed, stirred for 12 min, then trifluoromethanesulfonic acid is added, stirred at 65℃, 150 rpm for 5 h, and the solvent is evaporated to obtain the modified citric acid; wherein, the mass ratio of the citric acid, imino oxalic acid, trifluoromethanesulfonic acid and deionized water is 10:3:0.25:65.

[0071] The filtrate 2 also needs to be treated by a defluorination process, which specifically includes:

[0072] A1, the defluorination agent is added into the filtrate 2, stirred for 25 min, the PH is adjusted to 7.0, then stirred for 12 min, to obtain a mixed solution; wherein, when the concentration of fluorine atoms in the filtrate 2 is <5 ppm, the ratio of the defluorination agent to the filtrate 2 is 1L:1.0m 3 ; when 5ppm < concentration of fluorine atoms < 20ppm, the ratio of the defluorination agent to the filtrate 2 is 1.5L:1.0m 3 , and the defluorination agent is HPF3500 resin;

[0073] A2, anionic polyacrylamide was added into the mixed solution, stirred for 25 min, and stood for 1.5 h to obtain supernatant and sediment, the sediment was filtered to obtain filter cake b and filtrate 3; wherein the mass ratio of anionic polyacrylamide to mixed solution was 7:14.

[0074] Comparative Example 1

[0075] Comparative Example 1 was the same as Example 1, except that the preparation method of the deep eutectic solvent was different, and specifically as follows:

[0076] The deep eutectic solvent was prepared from benzyltrimethylammonium chloride and modified citric acid in a molar ratio of 2:1 by stirring at 70°C for 3h.

[0077] Comparative Example 2

[0078] Comparative Example 2 was the same as Example 1, except that the preparation method of the deep eutectic solvent was different, and specifically as follows:

[0079] The deep eutectic solvent was prepared from benzyltrimethylammonium chloride and dipentaerythritol in a molar ratio of 2:1.2 by stirring at 70°C for 3h.

[0080] Comparative Example 3

[0081] Comparative Example 3 was the same as Example 1, except that the preparation method of the modified citric acid was different, and specifically included:

[0082] The modified citric acid was prepared by the following method:

[0083] Citric acid, iminodiacetic acid and deionized water were mixed, stirred at 60°C and 100 rpm for 4h, and the solvent was evaporated to obtain modified citric acid; wherein the mass ratio of citric acid, iminodiacetic acid and deionized water was 8:2:60.

[0084] Comparative Example 4

[0085] Comparative Example 4 was the same as Example 1, except that the preparation method of the deep eutectic solvent was different, and specifically as follows:

[0086] The deep eutectic solvent was prepared from benzyltrimethylammonium chloride, citric acid and dipentaerythritol in a molar ratio of 2:1:1.2 by stirring at 70°C for 3h.

[0087] Comparative Example 5

[0088] Comparative Example 5 was the same as Example 1, except that the preparation method of the deep eutectic solvent was different, and specifically included:

[0089] The deep eutectic solvent was prepared from benzyltrimethylammonium chloride, citric acid and dipentaerythritol in a molar ratio of 2:1:1.2 by stirring at 70°C for 3h.

[0090] Comparative Example 6

[0091] Comparative Example 6 is the same as Example 1, except that the preparation method of the deep eutectic solvent is different, specifically comprising:

[0092] The deep eutectic solvent is prepared from benzyltrimethylammonium chloride, modified citric acid and pentaerythritol in a molar ratio of 2:1:1.2, stirring at 70℃ for 3h.

[0093] Comparative Example 7

[0094] Comparative Example 7 is the same as Example 1, except that the preparation method of the modified activated carbon is different, specifically comprising:

[0095] The modified activated carbon is prepared by the following method:

[0096] The activated carbon and iron nitrate nonahydrate are added to a high-pressure reaction kettle, and then deionized water and ascorbic acid are added. After stirring at 150rpm for 10min, stirring is carried out at 60℃ and 100rpm for 10h. After cooling to room temperature, filtration is carried out, and washing is carried out with deionized water for 3 times. Drying is carried out at 70℃ for 3h. Heating is carried out to 600℃ under a nitrogen atmosphere, and heating is carried out for 8h to obtain the modified activated carbon; wherein, in terms of mass parts: activated carbon 15 parts, iron nitrate nonahydrate 3 parts, ascorbic acid 0.05 parts, deionized water 60 parts;

[0097] Comparative Example 8

[0098] Comparative Example 8 is the same as Example 1, except that the preparation method of the modified activated carbon is different, specifically comprising:

[0099] The modified activated carbon is prepared by the following method:

[0100] The activated carbon is dispersed in N,N-dimethylformamide, and oxalic acid is added. Stirring is carried out at 60℃ and 100rpm for 20min. Then, 3-chloro-2-hydroxypropane sulfonic acid sodium and triethylamine are added. Stirring is carried out at 60℃ and 100rpm for 3h. Filtration is carried out, and washing is carried out with deionized water for 3 times. Drying is carried out at 70℃ for 3h to obtain the modified activated carbon; wherein, the mass ratio of activated carbon, oxalic acid, 3-chloro-2-hydroxypropane sulfonic acid sodium, triethylamine and N,N-dimethylformamide is 8:1:0.8:0.05:50.

[0101] Performance test

[0102] The manganese carbonate prepared in Examples 1-3 and Comparative Examples 1-8 is subjected to the following performance test:

[0103] The sulfate content of the manganese carbonate is tested according to the gravimetric method;

[0104] The manganese ion content in the manganese carbonate is tested according to the potassium permanganate titration method, the manganese carbonate is dissolved in a hydrochloric acid solution, and under the heating condition, the manganese carbonate is titrated with a potassium permanganate solution with a concentration of 0.05 mol / L until the pink color lasts for 30 seconds without fading, and the manganese content is calculated according to the consumed volume of the potassium permanganate.

[0105] The test results are shown in Table 1:

[0106] Table 1: Test results of Examples 1-3 and Comparative Examples 1-5

[0107]

[0108] From the test results in Table 1, it can be seen that the low eutectic solvent prepared by using benzyltrimethylammonium chloride, modified citric acid and dipentaerythritol can efficiently extract manganese in the electrolytic manganese anolyte, and the manganese carbonate product prepared by subsequent processes has high purity, has significant advantages in the process, is simple in process and operation, has low investment cost, is harmless to the environment, has broad application prospect and important economic value.

[0109] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for extracting high-purity manganese carbonate using electrolytic manganese anolyte, characterized in that, Includes the following steps: S1. Take the electrolytic manganese anolyte to be treated, adjust the pH to 6-6.5, add ammonium fluoride to the pH-adjusted electrolytic manganese anolyte, heat and stir for 2-3 hours, then add modified activated carbon, heat and stir for 2-3 hours, filter under pressure, and collect filtrate 1. S2. Mix the eutectic solvent with n-hexane at a mass ratio of 1-2:5-7 and stir for 8-12 min to obtain the organic phase. Mix the organic phase with filtrate 1 and stir for 1-2 h. Centrifuge to separate the layers and obtain the extract phase and raffinate. S3. Wash the extract phase obtained in step S2 with sulfuric acid, and back-extract with 4-6 mol / L sulfuric acid solution at a flow ratio of organic phase to aqueous phase of 6-10:1 to obtain a manganese-rich solution. S4. While stirring, add the manganese-rich solution to the ammonium bicarbonate solution, adjust the pH to 6-7, heat and stir for 8-12 hours, then let stand for 1-2 hours, filter by pressure to obtain filter cake a and filtrate 2. Wash and dry filter cake a to obtain manganese carbonate. The modified activated carbon in step S1 is prepared by the following method: A1. Add activated carbon and ferric nitrate nonahydrate to a high-pressure reactor, then add deionized water and ascorbic acid. Stir for 10-15 minutes, then heat to react for 10-15 hours. After cooling to room temperature, filter, wash, dry, and calcine to obtain composite activated carbon. A2. Disperse the composite activated carbon in N,N-dimethylformamide, add oxalic acid, heat and stir for 20-30 min, then add sodium 3-chloro-2-hydroxypropanesulfonate and triethylamine, heat and stir for 3-5 h, filter, wash, and dry to obtain modified activated carbon; The eutectic solvent in step S2 is prepared by stirring benzyltrimethylammonium chloride, modified citric acid and dipentaerythritol in a molar ratio of 2-4:1-3:1.2-1.8 at 70-90°C for 3-5 hours. The modified citric acid is prepared by the following method: Citric acid, iminoglycolic acid and deionized water are mixed and stirred for 10-15 minutes. Then trifluoromethanesulfonic acid is added, and the mixture is heated and stirred for 4-6 hours. The solvent is evaporated to obtain modified citric acid. The mass ratio of citric acid, iminoglycolic acid, trifluoromethanesulfonic acid and deionized water is 8-12:2-4:0.2-0.3:60-70.

2. The method for extracting high-purity manganese carbonate using electrolytic manganese anolyte according to claim 1, characterized in that, The mass ratio of ammonium fluoride, modified activated carbon, and electrolytic manganese anolyte in step S1 is 4-6:1-2:40-60.

3. The method for extracting high-purity manganese carbonate using electrolytic manganese anolyte according to claim 1, characterized in that, The mass fractions of each raw material in step A1 are as follows: 15-25 parts activated carbon, 3-5 parts ferric nitrate nonahydrate, 0.05-0.1 parts ascorbic acid, and 60-80 parts deionized water.

4. The method for extracting high-purity manganese carbonate using electrolytic manganese anolyte according to claim 1, characterized in that, In step A2, the mass ratio of composite activated carbon, oxalic acid, sodium 3-chloro-2-hydroxypropanesulfonate, triethylamine, and N,N-dimethylformamide is 8-12:1-2:0.8-1.2:0.05-0.1:50-60.

5. The method for extracting high-purity manganese carbonate using electrolytic manganese anolyte according to claim 1, characterized in that, In step S2, the mass ratio of organic phase to filtrate 1 is 3-5:5-8.

6. The method for extracting high-purity manganese carbonate using electrolytic manganese anolyte according to claim 1, characterized in that, The mass ratio of the manganese-rich solution to the ammonium bicarbonate solution in step S4 is 5-8:9-12.

7. The method for extracting high-purity manganese carbonate using electrolytic manganese anolyte according to claim 1, characterized in that, The filtrate 2 in step S4 also needs to be treated with a defluorinating agent.

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