Method for preparing battery grade manganese iron oxalate from electrolytic manganese anode slime and prepared manganese iron oxalate

Abstract

The method comprises the following steps that the electrolytic manganese anode slime is prepared into qualified liquid containing manganese sulfate and ferrous sulfate, then a solution containing oxalate is added to serve as a precipitator for a reaction, the pH value of a reaction system is controlled to range from 0.8 to 1.5 at the reaction endpoint, and the battery grade ferromanganese oxalate is obtained. And after the precipitation reaction is finished, filtering and separating out a solid, washing and drying to obtain a battery-grade oxalate ferromanganese product. By means of the method, the electrolytic manganese anode slime can be prepared into battery-grade ferromanganese oxalate, the ferromanganese oxalate can serve as a precursor of ferromanganese phosphate, meanwhile, high-grade lead slag can be separated out, and high-value utilization of the anode slime is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of high-value application of electrolytic manganese anode mud, in particular to a method for preparing battery-grade ferromanganese oxalate by using electrolytic manganese anode mud and the prepared ferromanganese oxalate. Background Art

[0002] Electrolytic manganese anode mud is a solid waste generated in the anode chamber during the electrolytic production of manganese metal. It contains a large amount of MnO2, SeO2, PbSO4 and (NH4)2SO4. Due to historical and technical reasons, electrolytic manganese enterprises mainly treat electrolytic manganese anode mud in the following ways: a small amount is used as an additive in steelmaking, and most of it is stored or sold cheaply as solid waste, with low added value. In addition, during this treatment process, heavy metals such as lead, selenium, manganese and ammonia nitrogen in the electrolytic manganese anode mud stored in the slag yard will penetrate into the surface water and groundwater with the leachate, seriously polluting the local ecological environment. In addition, with the green development of my country's electrolytic manganese industry, how to realize the resource utilization and high-value utilization of electrolytic manganese anode mud has become increasingly prominent. Therefore, the study of the high-value utilization of electrolytic manganese anode mud is an issue that must be solved for the sustainable development of electrolytic manganese enterprises.

[0003] At present, domestic and foreign scholars have conducted a lot of research on the resource utilization of manganese, lead and selenium in electrolytic manganese anode mud, among which the main focus is on the wet reduction leaching of manganese in anode mud. The main reducing agents include FeS2, SO2, CO, Na2SO3 and glucose. The manganese in the anode mud can be effectively leached by using wet reduction leaching technology to treat electrolytic manganese anode mud, but the impurities such as heavy metal lead, selenium and ammonia nitrogen in the anode mud still remain in the leaching solution and leaching residue, which is easy to cause secondary pollution. After the manganese is reduced and leached, it is mainly recovered in the form of electrolytic manganese metal and manganese sulfate, and the economic benefits are not significant. In summary, the current harmless treatment and resource utilization technology of electrolytic manganese anode mud at home and abroad mainly has the following problems: (1) complex process flow; (2) harmful impurities such as heavy metal lead and selenium in anode mud are difficult to remove, which pollutes the environment; (3) the high added value conversion rate is low and the economic benefits are not significant; (4) there are few diversified utilization channels.

[0004] Therefore, it is urgent to develop a way to remove impurities and purify electrolytic manganese anode mud to realize the resource and high-value utilization of electrolytic manganese anode mud. Summary of the invention

[0005] The invention discloses a method for preparing battery-grade ferromanganese oxalate by using electrolytic manganese anode mud and the prepared ferromanganese oxalate. The battery-grade ferromanganese oxalate is prepared by using electrolytic manganese anode mud and can be used as a precursor of ferromanganese phosphate to achieve high-value utilization of anode mud.

[0006] To achieve the above object, the technical solution of the present invention is:

[0007] A method for preparing battery-grade ferromanganese oxalate by electrolytic manganese anode mud comprises the following steps:

[0008] The electrolytic manganese anode mud is made into a qualified liquid containing manganese sulfate and ferrous sulfate, and then a solution containing oxalate is added as a precipitant to react. When the reaction end point is controlled, the pH value of the reaction system is 0.8-1.5. After the precipitation reaction is completed, the solid and the mother liquor are separated by filtration. The solid is washed and dried to obtain a battery-grade ferromanganese oxalate product.

[0009] Furthermore, in the qualified solution containing manganese sulfate and ferrous sulfate, Ca 2+ No more than 50mg / L, Mg 2+ No more than 30mg / L, Pb 2+ Not exceeding 5mg / L.

[0010] Furthermore, the steps of preparing the electrolytic manganese anode mud into a qualified liquid containing manganese sulfate and ferrous sulfate specifically include the following steps:

[0011] (1) Pre-treating the electrolytic manganese anode mud to reduce the Ca and Mg contents, thereby obtaining the impurity-free anode mud;

[0012] (2) adding the anode mud and iron powder after impurities removal into clean water for leaching, separating the leaching solution and the leaching residue after leaching, wherein the leaching residue is high-grade lead slag, and neutralizing the leaching solution, adjusting the pH value to 5.0-6.0, separating the solid from the liquid, and the liquid is the neutralization solution;

[0013] (3) The neutralization solution reduces its Pb 2+ After the reaction is completed, filter to obtain a qualified solution containing manganese sulfate and ferrous sulfate;

[0014] After the precipitation reaction is completed, the separated mother liquor may be reused or not reused in the subsequent step of preparing qualified liquid containing manganese sulfate and ferrous sulfate. The reuse operation is: returning to step (2) to replace clean water or mix with clean water to leaching the anode mud after impurities are removed.

[0015] Preferably, adding the oxalate-containing solution as a precipitant to react specifically comprises: slowly dropping the oxalate-containing solution into a qualified solution containing manganese sulfate and ferrous sulfate, the dropping time is controlled to be 1.5 to 6 hours, and the pH value of the reaction system is controlled to be 0.8-1.5 when the oxalate-containing solution is added. After the pH adjustment of the reaction system is completed, the reaction is continued to be stirred for more than 1.5 hours until the precipitation reaction is completed.

[0016] More preferably, in step (1), the Ca content of the anode mud after impurities removal does not exceed 400 ppm, and the Mg content does not exceed 100 ppm.

[0017] More preferably, in step (2), the neutralization reaction is specifically as follows: adding manganese powder for neutralization, reacting at 40-60° C. for 30-300 min, adjusting the pH value of the reaction system to 4.0-5.0, and then adjusting the pH value to 5.0-6.0 with an alkaline solution; or directly adjusting the pH value to 5.0-6.0 with manganese powder. The alkaline solution can be aqueous ammonia.

[0018] More preferably, in step (2), the amount of iron powder used is 1.1 to 1.8 times the amount of theoretical MnO2 in the anode mud.

[0019] More preferably, the oxalic acid in the oxalate-containing solution has a concentration of 5 to 25 wt %.

[0020] More preferably, in step (3), the neutralization solution reduces its Pb 2+ Content, a certain amount of ammonium sulfide solution can be added to remove part of the Pb.

[0021] Furthermore, the present invention also provides ferromanganese oxalate prepared by the above method.

[0022] Preferably, in the above-mentioned ferromanganese oxalate, the mass percentages of Mn and Fe are not less than 30%, the mass percentage of Ca is less than 23 ppm, the mass percentage of Mg is less than 31 ppm, and the mass percentage of Pb is less than 9 ppm.

[0023] The high-grade lead slag mentioned above generally refers to the slag having a lead content of more than 40wt%.

[0024] The above-mentioned method for preparing battery-grade ferromanganese oxalate using electrolytic manganese anode mud specifically comprises the following processing steps:

[0025] The main component of the anode mud after impurity removal is MnO2, which is leached in clean water by adding iron powder. The leaching reaction equation is:

[0026] MnO2+Fe+2H2SO4→MnSO4+FeSO4+2H2O

[0027] After leaching is completed, the leachate and the leaching residue are separated. The leaching residue is high-grade lead slag. The leachate is used for neutralization and weight removal. Among them, neutralization can adjust the leachate to a suitable pH for subsequent preparation of battery-grade ferromanganese oxalate. Weight removal is mainly to remove Pb to improve the quality of ferromanganese oxalate. After neutralization and weight removal, a qualified liquid containing manganese sulfate and ferrous sulfate can be obtained.

[0028] Finally, the qualified solution containing manganese sulfate and ferrous sulfate reacts with the solution containing oxalate to obtain battery-grade manganese ferrooxalate with low impurities. The remaining mother liquor can be returned to the liquid preparation system for re-liquid preparation.

[0029] The present invention has the following advantages:

[0030] (1) The method of the present invention can prepare battery-grade ferromanganese oxalate products with different molar ratios of manganese and iron, and high-grade lead slag can be separated during the preparation process, so that the Pb, Mn and Fe resources of electrolytic manganese anode mud can be effectively recovered, thereby achieving full resource recovery.

[0031] (2) The present invention directly prepares battery-grade ferromanganese oxalate from Mn and Fe in a qualified solution containing manganese sulfate and ferrous sulfate. The ferromanganese oxalate can be used as a precursor of ferromanganese phosphate and is an important raw material for preparing ferromanganese phosphate. The ferromanganese phosphate has a high market price and good market prospects, and can achieve high-value utilization of anode mud.

[0032] (3) The present invention can effectively realize the resource utilization of anode mud, effectively solve the problem of anode mud as solid waste polluting the environment, and has significant economic benefits and social effects. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] A method for preparing battery-grade ferromanganese oxalate by electrolytic manganese anode mud comprises the following steps:

[0035] The electrolytic manganese anode mud is made into a qualified liquid containing manganese sulfate and ferrous sulfate, and then a solution containing oxalate is added as a precipitant to react. When the reaction end point is controlled, the pH value of the reaction system is 0.8-1.5 (for example, 0.8, 1.0, 1.2, 1.4 or 1.5). After the precipitation reaction is completed, the solid is separated by filtration, and a battery-grade ferromanganese oxalate product is obtained after washing and drying.

[0036] Furthermore, in the qualified solution containing manganese sulfate and ferrous sulfate, Ca 2+ No more than 50mg / L, Mg 2+ No more than 30mg / L, Pb 2+ Not exceeding 5mg / L.

[0037] Furthermore, the steps of preparing the electrolytic manganese anode mud into a qualified liquid containing manganese sulfate and ferrous sulfate specifically include the following steps:

[0038] (1) Pre-treating the electrolytic manganese anode mud to reduce the Ca and Mg contents, thereby obtaining the impurity-free anode mud;

[0039] (2) adding the anode mud and iron powder after impurities removal into clean water for leaching, separating the leachate and the leach residue after leaching, wherein the leach residue is high-grade lead slag, and neutralizing the leachate to adjust the pH value to 5.0-6.0 (e.g., 5.0, 5.2, 5.4, 5.5, 5.7 or 6.0), separating the solid from the liquid, and the liquid is a neutralization solution;

[0040] (3) The neutralization solution reduces its Pb 2+ After the reaction is completed, filter to obtain a qualified solution containing manganese sulfate and ferrous sulfate;

[0041] After the precipitation reaction is completed, the separated mother liquor may be reused or not reused in the subsequent step of preparing qualified liquid containing manganese sulfate and ferrous sulfate. The reuse operation is: returning to step (2) to replace clean water or mix with clean water to leaching the anode mud after impurities are removed.

[0042] In some preferred embodiments of the present invention, adding an oxalate-containing solution as a precipitant to react specifically comprises: slowly dropping the oxalate-containing solution into a qualified solution containing manganese sulfate and ferrous sulfate, and controlling the dropping time to be 1.5 to 6 hours (e.g., 1.5 hours, 2 hours, 3 hours, 4 hours, 5 hours or 6 hours). When the oxalate-containing solution is added, the pH value of the reaction system is controlled to be 0.8-1.5 (e.g., 0.8, 1.0, 1.2, 1.4 or 1.5). After the pH adjustment of the reaction system is completed, continuing to stir the reaction for more than 1.5 hours until the precipitation reaction is completed.

[0043] In some preferred embodiments of the present invention, after the pH adjustment of the reaction system is completed, the stirring reaction is continued, and the stirring speed can be selected to be 200-500 r / min (for example, 200 r / min, 300 r / min, 400 r / min, 450 r / min or 500 r / min).

[0044] In some preferred embodiments of the present invention, the oxalate-containing solution is slowly dripped into the qualified solution containing manganese sulfate and ferrous sulfate. The slow dripping can be achieved by using a peristaltic pump.

[0045] In some preferred embodiments of the present invention, the iron powder is high-purity iron powder.

[0046] In some preferred embodiments of the present invention, in step (1), the Ca content of the anode mud after impurities removal does not exceed 400 ppm, and the Mg content does not exceed 100 ppm.

[0047] In some preferred embodiments of the present invention, in step (2), the neutralization reaction is specifically as follows: adding manganese powder for neutralization, reacting at 40-60°C (e.g., 40°C, 45°C, 50°C, 55°C, 60°C) for a reaction time of 30-300 min (e.g., 30 min, 50 min, 80 min, 100 min, 150 min, 200 min, 250 min, or 300 min), adjusting the pH value of the reaction system to 4.0-5.0 (e.g., 4.0, 4.1, 4.3, 4.5, 4.7, or 5.0), and then adjusting the pH value to 5.0-6.0 (e.g., 5.0, 5.2, 5.4, 5.5, 5.7, or 6.0) with an alkaline solution; or directly adjusting the pH value to 5.0-6.0 (e.g., 5.0, 5.2, 5.4, 5.5, 5.7, or 6.0) with manganese powder. Wherein, the alkaline solution can be selected from aqueous ammonia.

[0048] In some preferred embodiments of the present invention, in step (2), the amount of iron powder used is 1.1 to 1.8 times (e.g., 1.1 times, 1.2 times, 1.4 times, 1.6 times or 1.8 times) the amount of theoretical MnO2 in the anode mud.

[0049] In some preferred embodiments of the present invention, the oxalic acid in the oxalate-containing solution has an oxalic acid concentration of 5 to 25 wt % (eg, 5%, 10%, 15%, 20% or 25%).

[0050] In some preferred embodiments of the present invention, in step (3), the neutralization solution reduces its Pb 2+ A certain amount of ammonium sulfide solution can be added to remove part of the Pb. The mass percentage of the ammonium sulfide solution can be 5-30wt% (e.g., 5%, 10%, 15%, 20%, 25% or 30%).

[0051] In some preferred embodiments of the present invention, the solid separated by filtration is finally washed and dried to obtain a battery-grade ferromanganese oxalate product; wherein the washing can be specifically washed with clean water for 3 to 5 times, and the amount of clean water used is 15 to 30 times the mass of the solid. Drying can be carried out by drying or freeze drying, and the drying temperature can be 60 to 100°C.

[0052] Furthermore, the present invention also provides ferromanganese oxalate prepared by the above method.

[0053] In some preferred embodiments of the present invention, in the above-mentioned ferromanganese oxalate, the mass percentages of Mn and Fe are not less than 30%, the mass percentage of Ca is less than 23 ppm, the mass percentage of Mg is less than 31 ppm, and the mass percentage of Pb is less than 9 ppm.

[0054] The method for preparing battery-grade ferromanganese oxalate from electrolytic manganese anode mud provided by the present invention can prepare battery-grade ferromanganese oxalate products with different molar ratios of manganese and iron, and high-grade lead slag can be separated during the preparation process, so that the Pb, Mn, and Fe resources of the electrolytic manganese anode mud can be effectively recovered, and the full recovery of resources can be achieved. The present invention directly prepares battery-grade ferromanganese oxalate from Mn and Fe in a qualified solution containing manganese sulfate and ferrous sulfate, which can be used as a precursor of ferromanganese phosphate, is an important raw material for preparing ferromanganese phosphate, has a high market price and good market prospects, and can achieve high-value utilization of anode mud. And the present invention can effectively solve the problem of anode mud as solid waste polluting the environment by realizing the resource utilization of anode mud, and has significant economic benefits and social effects.

[0055] The present invention will be further described below by way of examples, but the protection scope of the present invention is not limited to these embodiments.

[0056] In the following embodiments, step (1) adopts the existing method to pretreat the electrolytic manganese anode mud. The main components of the electrolytic manganese anode mud are shown in Table 1. The pretreatment to reduce the Ca and Mg contents of the electrolytic manganese anode mud can adopt the existing method, such as: S1. First rinsing: the electrolytic manganese anode mud is washed with clean water, with a liquid-to-solid ratio of 4:1, stirred and washed, soluble Mn and ammonium sulfate are removed, filtered, and solids are separated; S2. Second rinsing: the solid separated in step S1 is added with sodium carbonate solution to modify calcium sulfate and magnesium sulfate, with a liquid-to-solid ratio of 4:1, stirred and reacted, filtered, and the obtained solid is modified anode mud; S3. Third rinsing: hydrochloric acid solution or sulfuric acid solution is added to react to dissolve impurities such as Ca and Mg, the impurities are dissolved into the solution, and the solid is separated by filtration; S4. Fourth rinsing: the solid separated in step S3 is washed with clean water, with a liquid-to-solid ratio of 4:1, stirred and washed, residual ions are washed, and the anode mud after impurities are removed is obtained. The obtained anode mud after impurities removal had a Ca content of 246.12 ppm and a Mg content of 15.15 ppm. The following examples all used the anode mud after impurities removal for subsequent treatment. More specific analysis results are shown in Table 2:

[0057] Table 1 Analysis results of main components of anode mud

[0058]

[0059] Table 2 Detection and analysis results of anode mud after pretreatment

[0060]

[0061] Example 1

[0062] (1) The electrolytic manganese anode mud is pretreated to reduce the Ca and Mg contents to obtain the impurity-free anode mud.

[0063] (2) 120 g of anode mud after impurity removal and 65 g of high-purity iron powder were added to 1 L of clean water for leaching. After the leaching was completed, the leachate and the leaching residue were separated. The leaching residue was high-grade lead slag. Metal manganese powder was added to the leachate for neutralization. The reaction time was 240 min at 60° C. until the pH of the reaction system was 4.5. Then, ammonia water was added to adjust the pH to 5.5. The solid-liquid separation was performed, and the liquid was the neutralization solution.

[0064] (3) Add a small amount of 20wt% ammonium sulfide solution to the neutralized solution to reduce its Pb 2+ After the reaction is completed, filter to obtain a qualified liquid containing manganese sulfate and ferrous sulfate.

[0065] (4) Slowly drop a 9.1 wt% oxalic acid solution into a qualified solution containing manganese sulfate and ferrous sulfate, and react for 2 h. When the reaction endpoint is controlled, the pH value of the reaction system is 1.0. After the pH adjustment of the reaction system is completed, the reaction is continued to be stirred for 2 h until the precipitation reaction is completed. After the precipitation reaction is completed, the solid and the mother liquor are separated by filtration. The solid is washed 5 times with clean water, and the amount of clean water used is 20 times the mass of the solid. After drying, 292.21 g of a battery-grade ferromanganese oxalate product is obtained.

[0066] Example 2

[0067] (1) The electrolytic manganese anode mud is pretreated to reduce the Ca and Mg contents to obtain the impurity-free anode mud.

[0068] (2) 70 g of anode mud after impurity removal and 40 g of high-purity iron powder were added to 1 L of clean water for leaching. After the leaching was completed, the leachate and the leaching residue were separated. The leaching residue was high-grade lead slag. Metal manganese powder was added to the leachate for neutralization. The reaction time was 250 min at 50° C. until the pH of the reaction system was 4.3. Then, ammonia water was added to adjust the pH to 5.2. The solid-liquid separation was performed, and the liquid was the neutralization solution.

[0069] (3) Add a small amount of 15wt% ammonium sulfide solution to the neutralized solution to reduce its Pb 2+ After the reaction is completed, filter to obtain a qualified liquid containing manganese sulfate and ferrous sulfate.

[0070] (4) Slowly drop a 10 wt % oxalic acid solution into a qualified solution containing manganese sulfate and ferrous sulfate, and react for 3 h. When the reaction endpoint is controlled, the pH value of the reaction system is 0.8. After the pH adjustment of the reaction system is completed, the reaction is continued to be stirred for 3 h until the precipitation reaction is completed. After the precipitation reaction is completed, the solid and the mother liquor are separated by filtration. The solid is washed 3 times with clean water, and the amount of clean water used is 25 times the mass of the solid. After drying, 232.86 g of a battery-grade ferromanganese oxalate product is obtained.

[0071] Example 3

[0072] (1) The electrolytic manganese anode mud is pretreated to reduce the Ca and Mg contents to obtain the impurity-free anode mud.

[0073] (2) 60 g of anode mud after impurity removal and 30 g of high-purity iron powder were added to 1 L of clean water for leaching. After the leaching was completed, the leachate and the leaching residue were separated. The leaching residue was high-grade lead slag. Metal manganese powder was added to the leachate for neutralization. The reaction time was 300 min at 40° C. until the pH of the reaction system was 4.7. Then, ammonia water was added to adjust the pH to 5.9. The solid-liquid separation was performed, and the liquid was the neutralization solution.

[0074] (3) Add a small amount of 15wt% ammonium sulfide solution to the neutralized solution to reduce its Pb 2+ After the reaction is completed, filter to obtain a qualified liquid containing manganese sulfate and ferrous sulfate.

[0075] (4) Slowly drop a 20 wt % oxalic acid solution into a qualified solution containing manganese sulfate and ferrous sulfate, and react for 2.5 h. When the reaction endpoint is controlled, the pH value of the reaction system is 1.2. After the pH adjustment of the reaction system is completed, the reaction is continued to be stirred for 2.5 h until the precipitation reaction is completed. After the precipitation reaction is completed, the solid and the mother liquor are separated by filtration. The solid is washed 4 times with clean water, and the amount of clean water used is 20 times the mass of the solid. After drying, 184.78 g of a battery-grade ferromanganese oxalate product is obtained.

[0076] The test results of the above Examples 1 to 3 are shown in Tables 3 to 8. The recovery rate of lead in the anode mud in Examples 1 to 3 is more than 98%; in the above examples, if the mother liquor separated after the precipitation reaction is completed is reused in the subsequent step of preparing a qualified solution containing manganese sulfate and ferrous sulfate, it returns to step (2) to replace clean water or mix with clean water, and leaches the anode mud after impurities are removed. According to comprehensive calculation, the recovery rate of manganese is more than 95%.

[0077] Table 3 Process data of preparing qualified solution containing manganese sulfate and ferrous sulfate in Example 1

[0078] name Mn(g / L) Fe(g / L) Ca(mg / L) Mg(mg / L) K(mg / L) Na(mg / L) Co(mg / L) neutralizing solution 83.14 62.85 13.14 4.57 167.91 31.01 0.574 Qualified liquid 84.14 60.33 14.06 4.65 168.22 30.47 0.235 name Ni(mg / L) Al(mg / L) Ti(mg / L) Cu(mg / L) Pb(mg / L) Cr(mg / L) Zn(mg / L) neutralizing solution 0.169 ND 0.086 0.324 4.29 0.305 1.33 Qualified liquid 0.084 ND ND 0.18 1.44 ND 1.21

[0079] Table 4 Test data of battery-grade ferromanganese oxalate product obtained in Example 1

[0080] Mn(%) Fe(%) Ca(ppm) Mg(ppm) K(ppm) Na(ppm) Co(ppm) index 5～25 5～25 ≤50 ≤200 ≤50 ≤50 ≤10 product 10.25 20.48 6.46 6.13 15.63 27.91 3.97 Ni(ppm) Al(ppm) Ti(ppm) Cu(ppm) Pb(ppm) Cr(ppm) Zn(ppm) index ≤10 ≤100 ≤80 ≤10 ≤10 ≤10 ≤50 product Not detected Not detected Not detected 0.59 8.67 0.50 17.93

[0081] Table 5 Process data of preparing qualified solution containing manganese sulfate and ferrous sulfate in Example 2

[0082]

[0083]

[0084] Table 6 Test data of battery-grade ferromanganese oxalate product obtained in Example 2

[0085] Mn(%) Fe(%) Ca(ppm) Mg(ppm) K(ppm) Na(ppm) Co(ppm) index 5～25 5～25 ≤50 ≤200 ≤50 ≤50 ≤10 product 15.36 15.85 5.81 30.22 1.27 Not detected 0.14 Ni(ppm) Al(ppm) Ti(ppm) Cu(ppm) Pb(ppm) Cr(ppm) Zn(ppm) index ≤10 ≤100 ≤80 ≤10 ≤10 ≤10 ≤50 product Not detected 0.73 Not detected Not detected 6.51 Not detected 2.13

[0086] Table 7 Process data of preparing qualified solution containing manganese sulfate and ferrous sulfate in Example 3

[0087] name Mn(g / L) Fe(g / L) Ca(mg / L) Mg(mg / L) K(mg / L) Na(mg / L) Co(mg / L) neutralizing solution 69.16 24.71 32.88 28.88 118.41 9.06 0.03 Qualified liquid 68.27 21.16 45.88 28.88 107.98 8.76 0.02 name Ni(mg / L) Al(mg / L) Ti(mg / L) Cu(mg / L) Pb(mg / L) Cr(mg / L) Zn(mg / L) neutralizing solution 0.14 Not detected Not detected 0.03 2.29 0.052 9.78 Qualified liquid Not detected Not detected Not detected Not detected Not detected Not detected 1.31

[0088] Table 8 Test data of battery-grade ferromanganese oxalate product obtained in Example 3

[0089]

[0090]

Claims

1. A method for preparing battery-grade ferromanganese oxalate using electrolytic manganese anode mud, characterized in that The following steps are involved: The electrolytic manganese anode mud is made into a qualified liquid containing manganese sulfate and ferrous sulfate, and then a solution containing oxalate is added as a precipitant to react. When the reaction end point is controlled, the pH value of the reaction system is 0.8-1.

5. After the precipitation reaction is completed, the solid and the mother liquor are separated by filtration. The solid is washed and dried to obtain a battery-grade ferromanganese oxalate product.

2. The method for preparing battery-grade ferromanganese oxalate using electrolytic manganese anode mud according to claim 1, characterized in that: In the qualified solution containing manganese sulfate and ferrous sulfate, Ca 2+ No more than 50mg / L, Mg 2+ No more than 30mg / L, Pb 2+ Not exceeding 5mg / L.

3. The method for preparing battery-grade ferromanganese oxalate from electrolytic manganese anode mud according to claim 1, characterized in that: The process of preparing electrolytic manganese anode mud into qualified liquid containing manganese sulfate and ferrous sulfate specifically comprises the following steps: (1) The electrolytic manganese anode mud is pretreated to reduce the Ca and Mg contents to obtain the impurity-free anode mud; (2) adding the anode mud and iron powder after impurities removal into clean water for leaching, separating the leaching solution and the leaching residue after leaching, wherein the leaching residue is high-grade lead slag, and neutralizing the leaching solution, adjusting the pH value to 5.0-6.0 for solid-liquid separation, and the liquid is a neutralization solution; (3) The neutralization solution reduces its Pb 2+ After the reaction is completed, filter to obtain a qualified solution containing manganese sulfate and ferrous sulfate; After the precipitation reaction is completed, the separated mother liquor may be reused or not reused in the subsequent step of preparing qualified liquid containing manganese sulfate and ferrous sulfate. The reuse operation is: returning to step (2) to replace clean water or mix with clean water to leaching the anode mud after impurities are removed.

4. The method for preparing battery-grade ferromanganese oxalate from electrolytic manganese anode mud according to claim 1, characterized in that: The method of adding the oxalate-containing solution as a precipitant to react specifically includes: slowly dropping the oxalate-containing solution into a qualified solution containing manganese sulfate and ferrous sulfate, controlling the dropping time to be 1.5-6 hours, and controlling the pH value of the reaction system to be 0.8-1.5 when the oxalate-containing solution is added. After the pH adjustment of the reaction system is completed, continuing to stir the reaction for more than 1.5 hours until the precipitation reaction is completed.

5. The method for preparing battery-grade ferromanganese oxalate from electrolytic manganese anode mud according to claim 3, characterized in that: In step (1), the Ca content of the anode mud after impurities removal does not exceed 400 ppm, and the Mg content does not exceed 100 ppm.

6. The method for preparing battery-grade ferromanganese oxalate from electrolytic manganese anode mud according to claim 3, characterized in that: In step (2), the neutralization reaction is specifically as follows: adding manganese powder for neutralization, reacting at 40-60° C. for 30-300 min, adjusting the pH value of the reaction system to 4.0-5.0, and then adjusting the pH value to 5.0-6.0 with an alkaline solution; or directly adjusting the pH value to 5.0-6.0 with manganese powder.

7. The method for preparing battery-grade ferromanganese oxalate from electrolytic manganese anode mud according to claim 6, characterized in that: In step (2), the amount of iron powder used is 1.1 to 1.8 times the amount of MnO2 in the anode mud.

8. The method for preparing battery-grade ferromanganese oxalate from electrolytic manganese anode mud according to claim 4, characterized in that: The oxalic acid in the oxalate-containing solution has a concentration of 5-25 wt %.

9. Ferromanganese oxalate obtained by the method described in any one of claims 1 to 8.

10. The ferromanganese oxalate according to claim 9, characterized in that: In the ferromanganese oxalate, the mass percentages of Mn and Fe are not less than 30%, the mass percentage of Ca is less than 23 ppm, the mass percentage of Mg is less than 31 ppm, and the mass percentage of Pb is less than 9 ppm.

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