阅读说明：本技术 一种电解锰的生产方法 (Production method of electrolytic manganese ) 是由 钟宏 王启任 王帅 狄家康 曹占芳 马鑫 于 2020-12-11 设计创作，主要内容包括：本发明公开一种电解锰的生产方法,包括浸出、除杂、萃取、反萃、电解及氨氮和镁回收的工序,通过将液体循环分为两个部分,大幅度减少循环溶液中杂质的累积,有效增加循环次数,而且处理后的氨氮和镁可直接回收利用,处理工艺简单,有效解决了氨氮和镁难处理和难回收的问题。另外,本发明整体工艺流程不仅增加水资源的循环次数,而且环境友好,不产生含氨氮电解锰渣,绿色环保。(The invention discloses a production method of electrolytic manganese, which comprises the procedures of leaching, impurity removal, extraction, back extraction, electrolysis and ammonia nitrogen and magnesium recovery. In addition, the whole process flow of the invention not only increases the cycle times of water resources, but also is environment-friendly, does not produce electrolytic manganese slag containing ammonia nitrogen, and is green and environment-friendly.)

1. The production method of electrolytic manganese is characterized by comprising the working procedures of leaching, impurity removal, extraction, back extraction, electrolysis and ammonia nitrogen and magnesium recovery, and specifically comprises the following steps:

s1, leaching: continuously leaching manganese ore by using an acid solution to obtain a leaching solution and leaching slag, and carrying out solid-liquid separation; the leachate does not contain nitrogen elements;

s2, removing impurities: adding an oxidant into the leachate obtained in the step S1 to oxidize low-valent iron, then adding alkali, adjusting the pH value of the leachate to 4-6, precipitating iron and aluminum in the leachate, then adding SDD to remove heavy metal impurities in the leachate, and filtering to obtain a precipitate and a purified solution; the base does not include or generate nitrogen element-containing ions;

s3, extraction: extracting manganese in the purified liquid in the step S2 by organic phase synergism to obtain a loaded organic phase and raffinate, washing the loaded organic phase by using the purified liquid to remove impurity magnesium in the loaded organic phase to obtain a manganese-rich loaded organic phase and a washing liquid, returning the washing liquid to the purified liquid for circulation, and returning the raffinate to the step S1 for leaching manganese ore;

s4, back extraction: carrying out back extraction on the manganese-rich loaded organic phase in the step S3 by using a sulfuric acid solution to obtain a manganese sulfate solution and a regenerated organic phase, separating the manganese sulfate solution and the regenerated organic phase, and returning the regenerated organic phase to the step S3 for recycling;

s5, electrolysis: adding ammonia water into the manganese sulfate solution obtained in the step S4 to adjust the pH value to 7, adding an additive selenium dioxide, electrolyzing to obtain electrolytic manganese and electrolyte, putting the electrolytic manganese into passivation solution to passivate to obtain an electrolytic manganese product, and returning the electrolyte to the step S4 for back extraction;

s6, ammonia nitrogen and magnesium recovery: circulating the electrolyte until the concentration of ammonium ions is 20-60 g/L and the concentration of magnesium ions is 20-35 g/L to form high-magnesium ammonium electrolyte, collecting the high-magnesium ammonium electrolyte by opening a circuit, extracting manganese in the high-magnesium ammonium electrolyte by adopting an organic phase and/or a regenerated organic phase, and then compressing the high-magnesium ammonium electrolyte after manganese extraction by adopting an evaporation system to separate out crystals; and then separating the crystal and the solution, and adding soluble phosphate into the separated solution to obtain the ammonium phosphate magnesium salt product.

2. The method for producing electrolytic manganese according to claim 1, wherein in step S2, the oxidant is manganese dioxide and/or hydrogen peroxide, the alkali is at least one of manganese carbonate ore, manganese carbonate, magnesium carbonate, calcium oxide, manganese monoxide, magnesium oxide, sodium hydroxide, and potassium hydroxide, and the pH of the purified solution is 1 to 7.

3. The method for producing electrolytic manganese according to claim 1, wherein said organic phase in step S3 is composed of an extractant and an organic diluent, and said extractant is at least one of octyldecanoic acid, N-hydroxyethyl neodecanoamide, di (2-ethylhexyl) phosphate, mono 2-ethylhexyl 2-phosphate, bis- (2,4, 4-trimethylpentyl) hypophosphorous acid; the organic diluent is sulfonated kerosene, No. 260 solvent oil, aviation kerosene, Escaid110 and C₈～C₁₃At least one of the higher alcohols of (a); the concentration of the extracting agent is 50-500 g/L.

4. The method for producing electrolytic manganese according to claim 3, wherein the extractant is a saponified extractant, and the saponification rate is 5% to 50%; the adopted saponifier is at least one of sodium hydroxide solution, sodium carbonate solution, sodium bicarbonate solution, ammonia water, ammonium carbonate solution, ammonium bicarbonate solution and magnesium hydroxide suspended matter.

5. The method for producing electrolytic manganese according to claim 1, wherein in step S1, the acidic solution is sulfuric acid and/or raffinate obtained in step S3, and the leaching process is controlled to have a liquid-solid ratio of 1.2-4: 1; the usage amount of the sulfuric acid is 188-425 kg/t of raw ore; the pH value of the leaching end point is 1-3.

6. The method for producing electrolytic manganese according to claim 1, wherein in step S3, the extraction is a multistage countercurrent extraction, the number of countercurrent extraction stages is 2 to 10, and the volume ratio of the organic phase to the aqueous phase, O: A, is controlled to be 1 to 6:1 during countercurrent extraction.

7. The method for producing electrolytic manganese according to claim 1, wherein in step S4, the stripping is a multi-stage counter-current stripping, the number of counter-current stripping stages is 2 to 10, and the volume ratio O: a of the organic phase to the aqueous phase during counter-current extraction is controlled to 5 to 10: 1.

8. The method for producing electrolytic manganese according to claim 1, wherein in step S4, the concentration of sulfuric acid in the sulfuric acid solution is 0.5 to 4 mol/L.

9. The method for producing electrolytic manganese according to claim 1, wherein in step S5, the concentration of ammonium sulfate in the electrolyte is 90-150 g/L, the concentration of manganese ions is 15-40 g/L, the pH is 6.5-8.5, the electrolysis temperature is 38-44 ℃, and the current density is 350-400A/m²。

10. The method for producing electrolytic manganese according to claim 1, wherein in step S6, the pH of the high magnesium ammonium electrolyte solution treated by the evaporation system is 4-5, and the ratio of the concentration of phosphorus to the concentration of nitrogen is 2-2.5: 1.

Technical Field

The invention relates to the technical field of hydrometallurgy, in particular to a production method of electrolytic manganese, and particularly relates to an environment-friendly production method of electrolytic manganese.

Background

The electrolytic manganese production in China mainly adopts a hydrometallurgical process of acid leaching electrolysis, as shown in figure 1, in the existing electrolytic manganese production method, comprises the working procedures of leaching, impurity removal and electrolysis, the leaching solution obtained after the leaching working procedure is finished is neutralized by ammonia water and is precipitated to remove iron and aluminum, and heavy metals are removed by sodium dimethyldithiocarbamate (SDD) to obtain manganese sulfate solution containing ammonia nitrogen with certain concentration, then the manganese sulfate solution is added with ammonia water and ammonium sulfate and then enters an electrolytic bath for circular electrolysis to prepare electrolytic manganese, in order to save cost and reduce environmental pollution, the electrolyzed electrolyte is used for leaching manganese carbonate ore, in the circulation process, ammonia nitrogen and magnesium ions are continuously accumulated to a saturated state along with the increase of the circulation times, the electrolysis process is influenced, the loss and pollution of ammonia nitrogen and magnesium resources are caused, and the ammonia nitrogen and the magnesium ions need to be discharged in an open circuit or treated when reaching a certain concentration. In the existing leaching process of electrolytic manganese, ammonia nitrogen-containing electrolyte is recycled, so that ammonia nitrogen is difficult to remove and recycle in leaching slag, and the defect that the ammonia nitrogen in the leaching slag cannot be recycled in the traditional process is overcome. In addition, the concentration of ammonia nitrogen and magnesium in the electrolyte is relatively high, and after the electrolyte enters circulation, along with the circulation and electrolysis, the ammonia nitrogen and magnesium are quickly accumulated in the electrolyte and need to be treated more frequently, so that the circulation of water resources is influenced, and further the resource waste is caused.

The Chinese patent application CN111592260A adopts an additive to convert soluble ammonium salt in electrolytic manganese slag with complex components into easily decomposed ammonium monohydrate for recycling, the Chinese patent application CN110639158A adopts calcium phosphate and low-grade magnesium oxide to precipitate and stably solidify heavy metal mainly as phosphate under the condition of weak base, ammonia nitrogen mainly as struvite, but the removal and recycling of ammonia nitrogen in slag are not realized, and the problems that the water resource circulation frequency is limited and the ammonia nitrogen cannot be reasonably utilized cannot be solved.

In addition, the electrolyte is circulated in a closed loop, and magnesium ions are continuously accumulated at the same time. The existence of high-concentration magnesium in the electrolytic manganese solution can reduce the current efficiency and increase the production cost, and beneficial components in the electrolyte can be lost due to the crystallization of the magnesium, the manganese sulfate and the ammonium sulfate; when the crystallization is serious, the circulation pipeline can be blocked, and the continuous production of electrolytic manganese is influenced. When the problem is serious, a part of the electrolyzed electrolyte must be discharged in an open circuit to reduce the accumulation of magnesium, but the method causes waste water pollution and loss of manganese. Some enterprises adopt a precipitation method to remove magnesium by fluoride, and the defects of the method are that the process flow is long, fluorine ions are remained, and the method is not favorable for recycling.

Therefore, a new environment-friendly and economic process is urgently needed to solve the problems of water resource waste and difficult ammonia nitrogen and magnesium treatment or recovery caused by the serious accumulation of ammonia nitrogen and magnesium in circulation in the existing production method of electrolytic manganese.

Disclosure of Invention

In order to solve the technical problems in the prior art, the application provides a production method of electrolytic manganese, which comprises the procedures of leaching, impurity removal, extraction, back extraction, electrolysis and ammonia nitrogen and magnesium recovery, the liquid circulation is divided into two parts, the accumulation of impurities in the circulating solution can be greatly reduced, the circulation times are effectively increased, the treated ammonia nitrogen and magnesium can be directly recycled, the treatment process is simple, and the problems of difficult treatment and difficult recovery of the ammonia nitrogen and the magnesium are effectively solved. In addition, the whole process flow of the production method not only increases the cycle times of water resources, but also is environment-friendly, does not generate electrolytic manganese slag containing ammonia nitrogen, and is environment-friendly.

In order to achieve the purpose, the technical scheme of the invention is as follows:

the production method of electrolytic manganese comprises the working procedures of leaching, impurity removal, extraction, back extraction, electrolysis and ammonia nitrogen and magnesium recovery, and specifically comprises the following steps:

s1, leaching: continuously leaching manganese ore by using an acid solution to obtain a leaching solution and leaching slag, and carrying out solid-liquid separation; the leachate does not contain nitrogen elements;

s2, removing impurities: adding an oxidant into the leachate obtained in the step S1 to oxidize low-valent iron, then adding alkali, adjusting the pH value of the leachate to 4-6, precipitating iron and aluminum in the leachate, then adding SDD to remove heavy metal impurities in the leachate, and filtering to obtain a precipitate and a purified solution; the base does not include or generate nitrogen element-containing ions;

s3, extraction: extracting manganese in the purified liquid in the step S2 by organic phase synergism to obtain a loaded organic phase and raffinate, washing the loaded organic phase by using the purified liquid to remove impurity magnesium in the loaded organic phase to obtain a manganese-rich loaded organic phase and a washing liquid, returning the washing liquid to the purified liquid for circulation, and returning the raffinate to the step S1 for leaching manganese ore;

s4, back extraction: carrying out back extraction on the manganese-rich loaded organic phase in the step S3 by using a sulfuric acid solution to obtain a manganese sulfate solution and a regenerated organic phase, separating the manganese sulfate solution and the regenerated organic phase, and returning the regenerated organic phase to the step S3 for recycling;

s5, electrolysis: adding ammonia water into the manganese sulfate solution obtained in the step S4 to adjust the pH value to 7, adding an additive selenium dioxide, electrolyzing to obtain electrolytic manganese and electrolyte, putting the electrolytic manganese into passivation solution to passivate to obtain an electrolytic manganese product, and returning the electrolyte to the step S4 for back extraction;

s6, ammonia nitrogen and magnesium recovery: circulating the electrolyte until the concentration of ammonium ions is 20-60 g/L and the concentration of magnesium ions is 20-35 g/L to form high-magnesium ammonium electrolyte, collecting the high-magnesium ammonium electrolyte by opening a circuit, extracting manganese in the high-magnesium ammonium electrolyte by adopting an organic phase and/or a regenerated organic phase, and then compressing the high-magnesium ammonium electrolyte after manganese extraction by adopting an evaporation system to separate out crystals; then separating the crystal and the solution, and adding soluble phosphate into the solution obtained after separation to obtain the magnesium ammonium phosphate byproduct.

In the above scheme, the reaction principles of steps S1 to S6 are as follows:

manganese ore generally contains impurities such as lead, nickel, copper, aluminum, iron, magnesium and the like besides manganese, firstly, an acidic solution is used for leaching the manganese ore to obtain a leaching solution, the manganese ore is dissolved in the acidic solution to generate a leaching solution rich in manganese metal ions and impurities such as metal ions including lead, aluminum, iron, magnesium and the like, and at the moment, the leaching solution is strong in acidity and low in pH;

carrying out an impurity removal process on the leachate, wherein iron in the leachate is generally low-valent iron ions, oxidizing the low-valent iron by using an oxidant to convert the low-valent iron into high-valent iron ions, then adding alkali to remove metal ions such as aluminum, iron and the like, and neutralizing hydrogen ions in the leachate by using the alkali at the same time, so that the pH value of the leachate is increased, precipitating the iron and aluminum ions, adding an SDD chelating agent, and precipitating heavy metal ions such as lead, copper, nickel and the like through chelation; in the impurity removal process, low-valence iron ions generate high-valence (+ 3-valence) iron ions under the action of an oxidant, aluminum ions and the high-valence iron ions react with alkali to generate hydroxide precipitates, and heavy metal ions such as lead, copper and nickel and the like and an SDD chelating agent generate chelation to generate chelated precipitates; removing impurities, carrying out solid-liquid separation to obtain a purified solution, and after an impurity removing process, the purified solution is rich in manganese ions and magnesium ions, wherein the content of the manganese ions is 20-50 g/L, the content of the magnesium ions is 1-10 g/L, and the concentration of impurity ions such as iron, aluminum, nickel, copper, lead and the like is lower than 1 mg/L;

the method comprises the steps of extracting manganese in the purified liquid by organic phase synergism to obtain a loaded organic phase and raffinate, wherein the manganese and magnesium plasma concentration in the raffinate is very low, the raffinate can be used as a water resource for circularly leaching manganese ore, the loaded organic phase is rich in manganese and impurity magnesium, the purified liquid is used for washing the loaded organic phase to remove the impurity magnesium attached to the organic phase to obtain the loaded organic phase rich in manganese and the purified liquid, and the purified liquid used for washing can be directly returned to the purified liquid for circulation; the washed manganese-rich loaded organic phase is rich in manganese ions and a small amount of magnesium ion impurities, and the content of the magnesium ions is less than 0.3 g/L;

the leaching, impurity removal and extraction processes are all free of nitrogen elements, the concentration of metal ions in the solution after treatment is low, the solution can be recycled as water resources, the cycle frequency is greatly increased, the water resources are effectively utilized, and the waste of water resources is reduced.

In the back extraction process, a sulfuric acid solution is used as a water phase to back extract the manganese-rich loaded organic phase, and manganese ions and a small amount of magnesium ions are separated from the organic phase to generate a manganese sulfate solution and a regenerated organic phase; the manganese sulfate solution is used for the next electrolysis process, and the regenerated organic phase can be recycled for the extraction process;

an electrolysis process, namely adding a proper amount of ammonium sulfate into the manganese sulfate solution obtained after back extraction, adding ammonia water to adjust the pH value, and then carrying out electrolysis to generate electrolytic manganese and electrolyte, wherein manganese ions are converted into a manganese simple substance in the electrolysis process, the manganese ions are gradually reduced, the concentration of the manganese ions is reduced, the electrolyte contains ammonia nitrogen and magnesium ions, and the electrolyte can be circularly used in the back extraction process and is used for separating the manganese ions from an organic phase;

the method comprises the steps of (1) recycling ammonia nitrogen and magnesium, monitoring the concentration of ammonia nitrogen and magnesium ions in electrolyte in real time in the electrolytic process, gradually increasing the concentration of ammonia nitrogen and magnesium ions in the electrolyte along with the circulation of the electrolyte and the electrolysis process, collecting high-magnesium ammonium electrolyte by opening a circuit when the concentration of ammonia nitrogen is 20-60 g/L and the concentration of magnesium ions is 20-35 g/L, and extracting manganese in the high-magnesium ammonium electrolyte by using an organic phase and/or a regenerated organic phase to obtain a manganese-rich loaded organic phase after extraction because the manganese ions cannot be completely consumed in the electrolytic process, wherein the manganese-rich loaded organic phase can be added into the manganese-rich loaded organic phase obtained in the step S3 for circulation; then, compressing the extracted high-magnesium ammonium electrolyte by using an evaporation system to separate out ammonium sulfate crystals; separating the crystal and the solution to obtain an ammonium sulfate product; then adding soluble phosphate into the separated solution to obtain a magnesium ammonium phosphate byproduct; the ammonium sulfate product and the ammonium sulfate magnesium salt can be used as fertilizers, and certain economic benefit can be generated.

In some embodiments, in step S1, if the manganese ore is manganese oxide ore, a wet reduction leaching process is performed, and the reducing agent is at least one of sulfur dioxide, iron sulfide, ferrous sulfide, iron, oxalic acid, hydrogen peroxide, phenols and aromatic amines, methanol, and sugar organic substances such as glucose; if the manganese ore is other manganese ores such as manganese carbonate ore and the like, the manganese ore can be directly leached by an acid solution.

In some embodiments, in step S2, the oxidant is at least one of manganese dioxide, hydrogen peroxide, sodium chlorate, air, oxygen, and sulfur dioxide, and in order to avoid adding excessive impurities into the leachate, manganese dioxide and/or hydrogen peroxide are preferably selected, manganese ions generated after the reaction of manganese dioxide can be directly used for producing electrolytic manganese, and water generated after the reaction of hydrogen peroxide can be used for circulating in and out, and no other impurities are generated; the addition amount of the oxidant is 1.0-1.2 times of the theoretical molar amount in the reaction process; the alkali is at least one of manganese carbonate ore, manganese carbonate, magnesium carbonate, calcium oxide, manganese monoxide, magnesium oxide, sodium hydroxide and potassium hydroxide, and the pH of the purified liquid obtained after reaction is 1-7.

In some embodiments, the organic phase in step S3 is comprised of an extractant and an organic diluent, the extractant is at least one of caprylic capric acid, N-hydroxyethyl caprylocapramide, di (2-ethylhexyl) phosphate, mono 2-ethylhexyl 2-phosphate, bis- (2,4, 4-trimethylpentyl) hypophosphorous acid; the organic diluent is sulfonated kerosene, No. 260 solvent oil, aviation kerosene, Escaid110 and C₈～C₁₃At least one of the higher alcohols of (a); the concentration of the extracting agent is 50-500 g/L;

in some embodiments, the extractant is a saponified extractant, the saponification rate being 5% to 50%; the adopted saponifier is at least one of sodium hydroxide solution, sodium carbonate solution, sodium bicarbonate solution, ammonia water, ammonium carbonate solution, ammonium bicarbonate solution and magnesium hydroxide suspended matter.

In some embodiments, in step S1, the acidic solution is sulfuric acid and/or raffinate obtained in step S3, and the leaching process is controlled to have a liquid-solid ratio of 1.2-4: 1; the usage amount of the sulfuric acid is 188-425 kg/t of raw ore; the pH value of the leaching end point is 1-3.

In some embodiments, the extraction is multistage countercurrent extraction, the number of stages of the countercurrent extraction is 2-10, and the volume ratio of the organic phase to the aqueous phase during the countercurrent extraction is controlled to be 1-6: 1.

In some embodiments, the back extraction is multi-stage counter-current back extraction, the number of stages of the counter-current back extraction is 2-10, and the volume ratio of the organic phase to the aqueous phase during the counter-current extraction is controlled to be 5-10: 1.

In some embodiments, in step S4, the concentration of sulfuric acid in the sulfuric acid solution is 0.5-4: 1.

In some casesIn an embodiment, in step S5, the electrolyte solution has an ammonium sulfate concentration of 90-150 g/L, a manganese ion concentration of 15-40 g/L, a pH of 6.5-8.5, an electrolysis temperature of 38-44 ℃, and a current density of 350-400A/m²。

In some embodiments, in step S6, the pH of the high magnesium ammonium electrolyte solution after being processed by the evaporation system is 4-5, and the ratio of the concentration of the added phosphorus to the concentration of nitrogen in the solution is 2-2.5: 1.

In some embodiments, in step S6, the soluble phosphate is at least one of disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, tripotassium phosphate, trisodium phosphate.

Compared with the prior art, the invention has the following beneficial effects:

in the production method of electrolytic manganese, the applicant creatively introduces extraction and back extraction processes, and divides the liquid circulation of the whole production method of leaching, impurity removal, extraction, back extraction, electrolysis and ammonia nitrogen and magnesium recovery into two sections of circulation, wherein one section of circulation is the circulation of raffinate, and the raffinate after extraction is circularly used for leaching manganese ore, so that nitrogen-containing elements are not contained in the leaching, impurity removal and extraction processes, and metal ions in the raffinate after extraction are few, so that the raffinate can be basically used as an aqueous solution for the leaching process, the circulation can be realized for many times, the circulation frequency of the liquid is greatly improved, and the water resource use is saved; the other section of circulation is the circulation of the electrolyte, the electrolyte is circularly used for separating metal ions in an organic phase and an organic phase in a back extraction process to obtain a manganese sulfate solution, and the manganese sulfate solution is circularly used for electrolysis and back extraction processes, so that the use of a water phase in the back extraction process is reduced, the waste of the electrolyte or the subsequent treatment frequency of the electrolyte is reduced, and meanwhile, the acid in the electrolyte is fully utilized. The method not only effectively solves the problem that the electrolyte contains ammonia nitrogen leaching slag in the traditional process, reduces the treatment cost of the leaching slag, but also can reduce the loss of water resources.

In addition, the electrolyte with certain concentration of ammonia nitrogen and magnesium ions is treated by the production method, and the treated product is a crop fertilizer, so that economic benefits can be directly generated.

The production method of electrolytic manganese provided by the invention has the advantages that the process is simple, the aqueous solution in the process can be recycled, the loss of water resources is reduced, and the product of the treated electrolyte with ammonia nitrogen reaching a certain concentration can be used as a fertilizer for crops, so that economic benefits are directly generated, and the method has the characteristics of environmental protection and environmental friendliness.

In the whole process flow of the production method, acid-base adjustment is carried out through manganese ore or alkali to realize neutralization and remove iron and aluminum impurities, and raffinate is circulated to a leaching procedure, so that generation of nitrogen elements in the leachate is avoided, the problem that ammonia nitrogen leached slag is easily generated when ammonia nitrogen-containing electrolyte is directly circulated to the leaching procedure in the traditional process is effectively solved, the leached slag containing ammonia nitrogen is not generated, the production method is environment-friendly, and the production cost and the procedure for treating the leached slag are reduced; the extraction process is adopted to realize the separation of manganese and magnesium ions in the purified solution, the problem of high concentration of the magnesium ions in the purified solution can be solved, the content of the magnesium ions in the manganese sulfate solution obtained by the extraction process and the back extraction process is reduced to 0.3g/L from 2.48g/L in the purified solution, the electrolysis cycle times can be greatly improved, the frequency of discharging waste electrolyte due to overhigh content of the magnesium ions in an open circuit is reduced, and the environmental pollution is reduced; the high magnesium ammonium electrolyte is treated, firstly extracted, manganese ions are recovered, and the high magnesium ammonium electrolyte is circularly used for back extraction and enters the electrolyte, so that the waste of manganese metal is reduced, and on the other hand, the high magnesium ammonium electrolyte is treated to directly form an ammonium sulfate product and an ammonium sulfate magnesium salt product, both of which can be used as biological fertilizers, thereby not only generating economic benefits, but also reducing the cost for treating electrolytic slag, reducing the pollution of electrolytic waste liquid to the environment, being environment-friendly, and meeting the requirements of green and environmental protection.

Furthermore, the oxidant selected in step S2 adopts manganese dioxide and/or hydrogen peroxide which can react to generate manganese ions or water as the oxidant, thereby reducing the introduction of other impurities in the leachate, reducing the procedures and cost for treating other impurities, reducing the use of reagents for treating other impurities, and reducing the pollution to the environment; in step S3, the organic phase is used to extract manganese ions in cooperation with the organic phase, and the organic phase with a high extraction rate of manganese ions is used to extract manganese ions, so that manganese and magnesium can be effectively separated, the content of magnesium ions in the manganese sulfate solution is reduced, and the circulation frequency of the electrolyte is increased.

Drawings

FIG. 1 is a flow chart of a conventional electrolytic manganese production method;

FIG. 2 is a flow chart of the method for producing electrolytic manganese of the present invention.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Manganese ore used in the following examples of the invention is manganese carbonate ore from Guizhou, and the manganese grade is 10.50%; the agents used in the following examples are all commercially available unless otherwise specified.

Example 1

As shown in fig. 2, a method for producing electrolytic manganese, which comprises the steps of leaching, impurity removal, extraction, back extraction, electrolysis and ammonia nitrogen and magnesium recovery, comprises the following steps:

s1, leaching: diluting 8.5021g of concentrated sulfuric acid to 80mL by using water, adding 20g of manganese ore, stirring and leaching at 50 ℃ for 5h, and filtering to obtain a leaching solution and leaching residues, wherein the end point pH of the leaching solution is 1.44, the leaching rate of manganese is 96.99%, and the concentrations of elements in the leaching solution are as follows: mn 25.46g/L, Mg 1.76.76 g/L, Fe 2.13.13 g/L, Na 0.27.27 g/L, Ca 0.24.24 g/L and Al 0.08g/L;

s2, removing impurities: adding manganese dioxide into the leachate obtained in the step S1 to oxidize low-valent iron, wherein the ratio of the amount of substances added in the manganese dioxide to the amount of substances of low-valent iron in the leachate is 0.5:1, then adding sodium hydroxide to adjust the pH value to 5.38 to precipitate Fe and Al ions, then adding SDD to react to generate chelate precipitate (calculated according to the amount of substances of heavy metal ions in the purification solution and added according to the theoretical calculation amount, in the embodiment, the addition amount of SDD is 0.56 kg/ton of raw ore), and filtering to obtain impurity metal precipitate and purification solution, wherein the concentrations of the metal ions in the purification solution are respectively: mn 25.42g/L, Mg 1.75g/L, Fe < 1Mg/L, Al < 1Mg/L, Ni < 1Mg/L, Cu < 1 Mg/L;

s3, extraction: and (4) performing 2-stage countercurrent extraction on the purified liquid obtained in the step (S2) and the organic phase with the saponification rate of 30% to obtain a loaded organic phase and a raffinate, wherein the extraction rate of the organic phase to manganese ions is 98.03%, the extraction rate of the magnesium ions is 46.86%, and the concentrations of the manganese ions and the magnesium ions in the raffinate are 0.50g/L and 0.93g/L respectively through detection. And (3) allowing raffinate to enter a leaching process for circulation, washing the loaded organic phase by adopting a purifying solution, removing impurity magnesium in the loaded organic phase by utilizing the characteristic that the extraction rate of organic phase to manganese is greater than that of magnesium to obtain a manganese-rich loaded organic phase and a washing solution, and returning the washing solution to the purifying solution for circulation. After being washed by the purifying liquid, the content of manganese ions in the manganese-rich loaded organic phase is increased by 23.96 percent, the content of magnesium ions is removed by 78.04 percent (taking the content of corresponding ions in the loaded organic phase as unit 1), the concentration of the manganese ions in the washing liquid is 19.45g/L, and the concentration of the magnesium ions is 2.39 g/L; wherein the organic phase consists of an extracting agent and a diluent, the extracting agent is caprylic-capric acid with the concentration of 300g/L, and the diluent is No. 260 solvent oil; the extractant in the organic phase is firstly saponified by 30 percent of sodium hydroxide solution, and the saponification rate is 30 percent; controlling the volume ratio of the organic phase to the water phase to be 3:1 in the countercurrent extraction process;

s4, back extraction: carrying out 2-stage countercurrent back extraction on the manganese-rich loaded organic phase and a sulfuric acid solution with the concentration of 1mol/L according to the volume ratio of the organic phase to the water phase of 6:1 to obtain a regenerated organic phase and a back extraction solution (namely a manganese sulfate solution); the back extraction rate of manganese ions in the manganese-rich loaded organic phase is 98.45 percent, and the back extraction rate of magnesium ions is 97.32 percent, wherein the concentration of the manganese ions in the primary back extraction solution is 29.98g/L, and the concentration of the magnesium ions in the primary back extraction solution is 0.17 g/L; the regenerated organic phase enters an extraction process to be circulated;

s5, electrolysis: adding ammonium sulfate and selenium dioxide into the stripping solution obtained in the step S4, wherein the concentration of the ammonium sulfate is 120g/L, the concentration of manganese ions in the diluted stripping solution is 25g/L, then adding ammonia water to adjust the pH value to 7, and carrying out electrolysis; wherein the anolyte is ammonium sulfate solution with concentration of 120g/L, the catholyte is back extraction solution added with ammonium sulfate and selenium dioxide, the concentrations of ammonia nitrogen and magnesium ions in the catholyte are monitored in real time, and the current density is 350A/m²Electrolyzing for 1.5h at 40 ℃ and 0.26A to obtain an electrolytic manganese product and electrolyte, and circulating the electrolyte in a back extraction process;

s6, ammonia nitrogen and magnesium recovery: with the continuous circulation of the electrolyte, the concentration of ammonia nitrogen and magnesium ions in the electrolyte continuously rises, when the concentration of ammonia nitrogen in the electrolyte reaches 20-60 g/L and the concentration of magnesium ions reaches 20-35 g/L, the electrolysis is suspended, an open circuit is adopted to collect the high magnesium ammonium electrolyte, the organic phase and/or the regenerated organic phase in the step S3 is adopted to extract manganese in the high magnesium ammonium electrolyte, then an evaporation system is adopted to compress the high magnesium ammonium electrolyte after manganese extraction to separate out ammonium sulfate crystals, crystals and solution are separated, and disodium hydrogen phosphate is added into the solution obtained after solid-liquid separation to obtain an ammonium phosphate magnesium salt product; the manganese obtained by extraction enters a back extraction process for back extraction treatment, so that the circulation of manganese ions is realized, the consumption or discharge waste of manganese is reduced, and the ammonium sulfate crystals and the ammonium magnesium phosphate can be used as biological fertilizers.

Example 2

As shown in figure 1, the production method of electrolytic manganese comprises the working procedures of leaching, impurity removal, extraction, back extraction, electrolysis and ammonia nitrogen and magnesium recovery, and specifically comprises the following steps:

s1, leaching: diluting 8.4911g of concentrated sulfuric acid to 60mL by using water, adding 20g of manganese ore, stirring and leaching at 50 ℃ for 5h, and filtering to obtain a leaching solution and leaching residues, wherein the leaching end point pH is 1.25, the leaching rate of manganese is 97.43%, and the leaching rate of each element in the leaching solution is as follows: the leaching rate of manganese is 97.43 percent, the leaching rate of magnesium is 69.12 percent, and the leaching rate of iron is 94.74 percent;

s2, removing impurities: adding hydrogen peroxide into the leachate obtained in the step S1 to oxidize the low valenceAdding iron, wherein the ratio of the amount of substances added with hydrogen peroxide to the amount of substances of low-valent iron in the leachate is 1:1, then adding calcium oxide to adjust the pH value to 5.18, and precipitating Fe³⁺And Al^{3 +}Then adding SDD to react to generate chelate precipitate (the amount is calculated according to the amount of the heavy metal ion in the purified solution and added according to theoretical calculation, in the embodiment, the addition amount of SDD is 0.56 kg/ton of raw ore), and filtering to obtain impurity metal precipitate and purified solution, wherein the concentrations of the metal ions in the purified solution are respectively: mn is 34.09g/L, Mg is 2.35g/L, Fe is less than 1Mg/L, Al and less than 1Mg/L, Ni is less than 1Mg/L, and Cu is less than 1 Mg/L;

s3, extraction: and (3) performing 2-stage countercurrent extraction on the purified liquid obtained in the step (S2) and the organic phase with the saponification rate of 30% to obtain a loaded organic phase and raffinate, wherein the organic phase has a manganese ion extraction rate of 99.03% and a magnesium ion extraction rate of 46.38% through detection, and the concentrations of manganese ions and magnesium ions in the raffinate are 0.33g/L and 1.26g/L respectively. And (3) allowing raffinate to enter a leaching process for circulation, washing the loaded organic phase by adopting a purifying solution, removing impurity magnesium in the loaded organic phase by utilizing the characteristic that the extraction rate of organic phase to manganese is greater than that of magnesium to obtain a manganese-rich loaded organic phase and a washing solution, and returning the washing solution to the purifying solution for circulation. After being washed by the purifying liquid, the content of manganese ions in the manganese-rich loaded organic phase is increased by 25.98 percent, the magnesium ions are removed by 69.72 percent (taking the content of corresponding ions in the loaded organic phase as unit 1), the concentration of the manganese ions in the washing liquid is 25.32g/L, and the concentration of the magnesium ions is 3.11 g/L; wherein the organic phase consists of an extracting agent and a diluent, the extracting agent is caprylic-capric acid with the concentration of 300g/L, and the diluent is No. 260 solvent oil; the extractant in the organic phase is firstly saponified by sodium bicarbonate, and the saponification rate is 30 percent; controlling the volume ratio of the organic phase to the water phase to be 3:1 in the countercurrent extraction process;

s4, back extraction: carrying out 2-stage countercurrent back extraction on the manganese-rich loaded organic phase and a sulfuric acid solution with the concentration of 1mol/L according to the volume ratio of the organic phase to the water phase of 5:1 to obtain a regenerated organic phase and a back extraction solution (namely a manganese sulfate solution); the back extraction rate of manganese ions in the manganese-rich loaded organic phase is 98.98 percent, and the back extraction rate of magnesium ions is 98.17 percent, wherein the concentration of the manganese ions in the primary back extraction solution is 35.08g/L, and the concentration of the magnesium ions in the primary back extraction solution is 0.27 g/L; the regenerated organic phase enters an extraction process to be circulated;

s5, electrolysis: adding ammonium sulfate and selenium dioxide into the stripping solution obtained in the step S4, wherein the concentration of the ammonium sulfate is 120g/L, the concentration of manganese ions in the diluted stripping solution is 25g/L, then adding ammonia water to adjust the pH value to 7, and carrying out electrolysis; wherein the anolyte is ammonium sulfate solution with concentration of 120g/L, the catholyte is back extraction solution added with ammonium sulfate and selenium dioxide, the concentrations of ammonia nitrogen and magnesium ions in the anolyte are monitored in real time, and the current density is 400A/m²Electrolyzing for 1.5h at 40 ℃ and 0.26A at 83.21% current efficiency to obtain electrolytic manganese product and electrolyte, and circulating the electrolyte in a back extraction process;

s6, ammonia nitrogen and magnesium recovery: with the continuous circulation of the electrolyte, the concentration of ammonia nitrogen and magnesium ions in the electrolyte continuously rises, when the concentration of ammonia nitrogen in the electrolyte reaches 20-60 g/L and the concentration of magnesium ions reaches 20-35 g/L, the electrolysis is suspended, an open circuit is adopted to collect the high magnesium ammonium electrolyte, the organic phase and/or the regenerated organic phase in the step S3 is adopted to extract manganese in the high magnesium ammonium electrolyte, then an evaporation system is adopted to compress the high magnesium ammonium electrolyte after manganese extraction to separate out ammonium sulfate crystals, crystals and solution are separated, and disodium hydrogen phosphate is added into the solution obtained after solid-liquid separation to obtain an ammonium phosphate magnesium salt product; the manganese obtained by extraction enters a back extraction process for back extraction treatment, so that the circulation of manganese ions is realized, the consumption or discharge waste of manganese is reduced, and the ammonium sulfate crystals and the ammonium magnesium phosphate can be used as biological fertilizers.

Example 3

The method for producing electrolytic manganese in this example is the same as that of example 1, except that in step S3, bis- (2,4, 4-trimethylpentyl) hypophosphorous acid is used as an extractant, the concentration is 280g/L, 30% by mass of sodium hydroxide solution is used for saponification until the saponification rate is 30%, the pH of the purified solution is adjusted to 4, the volume ratio of the organic phase to the aqueous phase is controlled to be 2:1 in the countercurrent extraction process, and the manganese ion extraction rate is 85.50% and the magnesium ion extraction rate is 8.13%.

Example 4

The method for producing electrolytic manganese in this example is the same as that of example 1, except that in step S3, bis (2-ethylhexyl) phosphate is used as an extraction agent, the concentration is 500g/L, 30% by mass sodium hydroxide solution is used for saponification until the saponification rate is 30%, the pH of the purified solution is adjusted to 5, the volume ratio of the organic phase to the aqueous phase is controlled to be 1.2:1 during the countercurrent extraction, and the manganese ion extraction rate is 74.31%, and the magnesium ion extraction rate is 12.39%.

Example 5

The method for producing electrolytic manganese in this example is the same as that of example 1, except that in step S3, 2-ethylhexyl phosphate mono-2-ethylhexyl ester is used as the extractant, the concentration is 100g/L, 30% sodium hydroxide solution is used for saponification until the saponification rate is 30%, the pH of the purified solution is adjusted to 5, the volume ratio of the organic phase to the aqueous phase in the countercurrent extraction process is controlled to 6:1, and the manganese ion extraction rate is 81.97%, and the magnesium ion extraction rate is 10.42%.

Example 6

The production method of electrolytic manganese in this example is the same as that in example 1, except that in step S3, N-hydroxyethyl caprylocapramide and caprylic/capric acid are used as extraction agents in cooperation, the concentration of N-hydroxyethyl caprylocapramide is 50g/L, the concentration of caprylic/capric acid is 350g/L, sodium hydroxide solution with the mass fraction of 30% is used to saponify caprylic/capric acid until the saponification rate is 30%, the pH of the purified solution is adjusted to be 2, the volume ratio of organic phase to aqueous phase is controlled to be 1.5:1 in the countercurrent extraction process, and the manganese ion extraction rate is 95.73%, and the magnesium ion extraction rate is 19.27%.

The high-magnesium ammonium solution after manganese extraction is treated by an evaporation system, namely, the high-magnesium ammonium solution is evaporated and concentrated by the evaporation system according to the national standard GB/T36496-2018, the concentrated high-temperature supersaturated solution enters a cooling crystallization system, an ammonium sulfate product and an evaporation residual liquid are obtained after cooling, crystallization and separation, disodium hydrogen phosphate is added into the evaporation residual liquid to react to generate an ammonium phosphate magnesium salt, wherein the concentration ratio of phosphorus to nitrogen is 2-2.5: 1 after soluble phosphate is added.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.