Method for wet desulphurization of electrolytic manganese residues and separation and recycling of leachate

Abstract

The invention discloses a method for wet desulphurization of electrolytic manganese residues and separation and cyclic utilization of leachate, and relates to the field of solid waste resource utilization. The method comprises the steps that the electrolytic manganese residues and sylvite react under the stirring condition, solid-liquid separation is conducted on a product to obtain leaching residues A and a leaching solution A, and the mass ratio of the electrolytic manganese residues to the sylvite is 1: 0.1-1: 1; the leaching solution A is used for being mixed with electrolytic manganese residues to be treated, potassium salt is supplemented into the mixed solution, the mass ratio of the electrolytic manganese residues to the potassium salt is 1: 0.1-1: 1, and after the reaction is finished, solid-liquid separation is conducted on a product to obtain leaching residues A and enriched concentrated liquor B; the obtained leaching residues A are subjected to countercurrent washing, washing residues B are obtained, and the washing residues B are used for resource utilization; evaporating and crystallizing the obtained enriched concentrated liquor B, cooling and filtering to obtain a potassium sulfate product, and recycling the potassium sulfate product. According to the method, sulfur and solidified heavy metal in the electrolytic manganese residues can be efficiently removed, and separation and cyclic utilization of valuable components in the leachate can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste resource utilization, and in particular to a method for wet desulfurization of electrolytic manganese slag and separation and recycling of leaching liquid. Background Art

[0002] Electrolytic manganese slag is a high-water content industrial solid waste produced by leaching manganese ore during the production of electrolytic manganese metal. Every ton of electrolytic manganese metal produced will emit 8 to 12 tons of electrolytic manganese slag and 1.2 to 1.5 tons of CO 2 , large amounts of electrolytic manganese slag and CO are discharged 2 The local ecological environment has been seriously polluted. In the past few decades, the stockpile of electrolytic manganese slag in my country has exceeded 160 million tons and is still growing at a rate of 8 million tons per year.

[0003] The main reason why electrolytic manganese slag is difficult to be harmlessly disposed of and recycled is that the electrolytic manganese slag contains CaSO 4 ·2H 2 O、MnSO 4 MgSO 4 NH 4 ) 2 SO 4 And complex salts containing manganese, magnesium, iron, ammonium, etc., Fe(OH) 3 Minerals such as colloids and heavy metals. Domestic and foreign scholars have conducted a lot of research on the treatment and disposal of electrolytic manganese slag. The main purpose of harmless treatment is to prevent the easily migrated ammonium ions (NH 4 + ) ions, manganese and other heavy metal elements enter the environment. To completely solve the pollution problem of electrolytic manganese slag, it is necessary to realize its resource utilization. The core problem lies in the large amount of sulfate and residual heavy metals contained in the electrolytic manganese slag, which directly leads to low dosage in the resource utilization process, high calcination cost, excessive heavy metal content in products, and frost, cracking and damage of building products.

[0004] At present, the treatment methods for sulfate and heavy metals in electrolytic manganese slag at home and abroad mainly include pyrolysis and wet treatment. Pyrolysis calcination technology can efficiently remove sulfate and solidify heavy metals, but the calcination energy consumption is high and it is difficult for general enterprises to bear. Wet desulfurization technology mainly includes water washing, acid leaching and alkali leaching. Among them, although the water washing method can achieve the removal of its soluble sulfate, there are problems such as large amount of slag washing water, difficult removal of gypsum in electrolytic manganese slag, and low safety of resource products, which directly limit the promotion and application of this technology. Both acid leaching and alkali leaching methods can make the desulfurization rate in electrolytic manganese slag reach more than 90%, but ammonium salt and chloride salt systems are mostly used. Ammonia and chlorine will be further introduced into the electrolytic manganese slag during the dosing process, which will increase the complexity of the subsequent leaching slag washing process and the difficulty of separating and recycling the leachate, increase the processing cost, and at the same time be unfavorable for subsequent resource utilization. Therefore, there is an urgent need to find a new method that is simple in process, easy to operate, and has low energy consumption, which can not only remove sulfur and solidify heavy metals in electrolytic manganese slag, but also separate and recycle the valuable components in the leachate. Summary of the invention

[0005] The invention discloses a method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate, so as to solve the technical problems that the wet desulfurization technology of electrolytic manganese slag in the related technology adopts ammonium salt and chloride salt system, and the subsequent washing process of leaching slag is complicated and the separation and recycling of leachate is difficult.

[0006] In order to solve the above problems, the present invention adopts the following technical solutions:

[0007] The method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate of the present invention comprises the following method:

[0008] Step 100: adding electrolytic manganese slag and potassium salt into a reaction tank, and adding water into the reaction tank, the electrolytic manganese slag and potassium salt react under stirring conditions, and after the reaction is completed, performing solid-liquid separation on the product to obtain leaching slag A and leaching liquid A, wherein the mass ratio of the electrolytic manganese slag to the potassium salt is 1:0.1 to 1:1;

[0009] Step 200: the leachate A is mixed with the electrolytic manganese slag to be treated, and potassium salt is added to the mixed solution so that the mass ratio of the electrolytic manganese slag to the potassium salt is 1:0.1 to 1:1. After the reaction is completed, the product is subjected to solid-liquid separation to obtain the leachate slag A and the enriched concentrated solution B;

[0010] Step 300: counter-currently washing the leached residue A obtained in step 100 and step 200 to obtain washed residue B, which is used for resource utilization;

[0011] Step 400: evaporating and crystallizing the concentrated solution B obtained in step 200, cooling and filtering to obtain a potassium sulfate product, which is used for resource utilization;

[0012] Step 500: The solution C obtained by evaporation and crystallization in step 400 is circulated for multiple times to generate an enriched solution E, and the enriched solution E is evaporated and crystallized, cooled and filtered to obtain ammonium sulfate and sodium sulfate crystals, and the ammonium sulfate and sodium sulfate are used for resource utilization.

[0013] According to an optional embodiment, the solution C obtained by evaporation and crystallization in step 400 and the solution F obtained by evaporation and crystallization in step 500 are used to mix with the electrolytic manganese slag to be treated;

[0014] The distilled water obtained by evaporation and crystallization in step 400 and step 500 is used for countercurrent washing in step 300;

[0015] The high-concentration washing liquid D obtained by countercurrent washing in step 300 is used to mix with the electrolytic manganese slag to be treated.

[0016] According to an optional embodiment, the mass ratio of electrolytic manganese slag to potassium salt is 1:0.5 to 1:1.

[0017] According to an optional embodiment, the potassium salt is potassium carbonate and / or potassium bicarbonate;

[0018] Alternatively, the potassium salt is a complex of potassium hydroxide and potassium bicarbonate and / or potassium carbonate.

[0019] According to an optional embodiment, in step 100, the reaction pH is 7-12.

[0020] According to an optional embodiment, in step 100, the reaction temperature is 25°C to 80°C, the reaction time is 30 to 240 min, and the stirring speed is 10 to 200 r / min.

[0021] According to an optional embodiment, in step 100, the solid-liquid ratio of electrolytic manganese slag to water is 1:3 to 1:7.

[0022] According to an optional embodiment, in step 300, the leached residue A is countercurrently washed 1 to 5 times.

[0023] According to an optional embodiment, in step 400, the temperature of evaporation and crystallization is 50°C to 200°C, and the temperature of cooling is 0°C to 50°C.

[0024] According to an optional embodiment, in step 500, the temperature of evaporation and crystallization is 50°C to 200°C, and the temperature of cooling is 0°C to 50°C.

[0025] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0026] The method for wet desulfurization of electrolytic manganese slag and separation and recycling of leaching solution of the present invention comprises adding potassium salt to the electrolytic manganese slag and controlling the mass ratio of the electrolytic manganese slag to the potassium salt to be 1:0.1 to 1:1, so that the sulfur in the electrolytic manganese slag can be converted into potassium sulfate. Specifically, the leaching rate of sulfur is higher than 90%, and the purity of the potassium sulfate product separated from the leaching solution can reach 99%. The method does not introduce ammonium salt and chloride salt components, and can not only efficiently remove sulfur and solidified heavy metals in the electrolytic manganese slag, but also the potassium salt can be recycled for resource utilization again, and the leached slag is also conducive to comprehensive resource utilization after countercurrent washing; in addition, the present invention has the advantages of simple process, easy operation and low energy consumption, and is of great significance to the realization of wet desulfurization and resource utilization of electrolytic manganese slag.

[0027] On the other hand, the method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate of the present invention can realize the separation and recycling of valuable components in the leachate. Specifically, the leachate A contains unreacted potassium salt, and the leachate A is used to mix with the electrolytic manganese slag to be treated. When the next batch of electrolytic manganese slag is leached, the amount of potassium salt added to the mixture of leachate A and electrolytic manganese slag is reduced, which is conducive to reducing the processing cost. When the leachate A is recycled 1 to 3 times, the resulting leachate is rich in potassium sulfate, and potassium sulfate can reach supersaturation and crystallization, which is also conducive to reducing the energy consumption of step 400 and can further reduce the processing cost. In addition, the leachate contains trace amounts of ammonium sulfate and sodium sulfate, and the concentration is high after multiple cycles of enrichment, which can be separated by evaporation concentration and cooling crystallization, thereby realizing its resource utilization, while avoiding affecting the normal operation of the process and the desulfurization effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a flow chart of the method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate in an embodiment of the present application. DETAILED DESCRIPTION

[0030] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0031] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0032] The acid leaching and alkali leaching methods used in the related technology can make the desulfurization rate in the electrolytic manganese slag reach more than 90%, but ammonium salt and chloride salt systems are mostly used. Ammonia and chlorine will be further introduced into the electrolytic manganese slag during the dosing process. Ammonium salt and chloride salt form complex salts with substances in the electrolytic manganese slag. The complex salts are not easy to separate, which will increase the complexity of the subsequent leaching slag washing process and the difficulty of separating and recycling the leachate, which is not conducive to subsequent resource utilization.

[0033] The invention adopts potassium salt system such as potassium bicarbonate, utilizes bicarbonate and manganese sulfate to generate manganese carbonate and potassium sulfate, and the potassium sulfate can be crystallized and separated by evaporation and concentration. Figure 1 The flowchart of the method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate in the embodiment of the present application is shown. Figure 1 It can be seen that the method of the present invention does not introduce additional ammonium salt and chloride salt components, which is conducive to the separation and quality improvement and recycling of the leachate, and is also conducive to the resource utilization of the leaching residue after desulfurization, and the entire process system realizes a green and low-carbon cycle. The method has the advantages of low energy consumption, simple operation, and easy equipment, and can also achieve the removal of sulfur from electrolytic manganese slag and the separation and recycling of valuable components in the leachate.

[0034] The following specific examples will describe in detail the method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate provided in the present application.

[0035] Example 1

[0036] 5kg electrolytic manganese slag and 2kg potassium bicarbonate were weighed and placed in a reaction tank, 25L water was added, the water bath temperature was adjusted to 50°C, and the mixture was stirred for 60min at a stirring speed of 100r / min to make it uniform, thereby obtaining a mixed system A. Then, the mixed system A was subjected to solid-liquid separation, the pH of the leaching solution was 7.8, and the calculated sulfur leaching rate was 90.24%. After the leached slag was washed with countercurrent water three times, the potassium content in the slag was measured to be as low as 1.17%, and the ammonia nitrogen concentration was 10.08mg / L, reaching the first-level A standard of GB8978-1996 standard. After the leaching solution was evaporated and crystallized at 100°C, it was cooled to 40°C to obtain a mixed system B, and the mixed system B was subjected to solid-liquid separation, and the obtained potassium sulfate solid purity was 99.29%.

[0037] Example 2

[0038] 5kg electrolytic manganese slag and 3kg potassium bicarbonate were weighed and placed in a reaction tank, 25L water was added, the water bath temperature was adjusted to 50°C, and the mixture was stirred for 60min at a stirring speed of 100r / min to make it uniform, thereby obtaining a mixed system A. Then, the mixed system A was subjected to solid-liquid separation, the pH of the leaching solution was 8.0, and the calculated sulfur leaching rate was 92.94%. After the leached slag was washed with countercurrent water three times, the potassium content in the slag was measured to be as low as 1.03%, and the ammonia nitrogen concentration was 10.14mg / L, reaching the first-level A standard of GB8978-1996 standard. After the leaching solution was evaporated and crystallized at 100°C, it was cooled to 40°C to obtain a mixed system B, and the mixed system B was subjected to solid-liquid separation, and the obtained potassium sulfate solid had a purity of 99.16%.

[0039] Example 3

[0040] Weigh 5kg of electrolytic manganese slag and 3.5kg of potassium carbonate into a reaction tank, add 25L of water, adjust the water bath temperature to 50°C, stir for 60min at a stirring speed of 100r / min to make it uniform, and obtain a mixed system A. Then, the mixed system A is subjected to solid-liquid separation, the pH of the leaching solution is 8.2, and the calculated sulfur leaching rate is 94.36%. After the leached slag is washed with countercurrent water three times, the potassium content in the slag is measured to be as low as 0.98%, and the ammonia nitrogen concentration is 11.29mg / L, reaching the first-level A standard of GB8978-1996 standard. After the leaching solution is evaporated and crystallized at 100°C, it is cooled to 40°C to obtain a mixed system B, and the mixed system B is subjected to solid-liquid separation, and the obtained potassium sulfate solid purity is 99.08%.

[0041] Example 4

[0042] 5kg electrolytic manganese slag, 0.5kg potassium hydroxide and 2kg potassium bicarbonate were weighed and placed in a reaction tank, 25L water was added, the water bath temperature was adjusted to 50°C, and the mixture was stirred for 60min at a stirring speed of 100r / min to make it uniform, thereby obtaining a mixed system A. Then, the mixed system A was subjected to solid-liquid separation, the pH of the leaching solution was 8.2, and the calculated sulfur leaching rate was 91.56%. After the leached slag was washed with countercurrent water three times, the potassium content in the slag was measured to be as low as 0.75%, and the ammonia nitrogen concentration was 9.62mg / L, reaching the first-level A standard of GB8978-1996 standard. After the leaching solution was evaporated and crystallized at 100°C, it was cooled to 40°C to obtain a mixed system B, and the mixed system B was subjected to solid-liquid separation, and the obtained potassium sulfate solid purity was 99.31%. After 10 cycles, an enriched solution E was obtained, which was evaporated and crystallized at 150° C. and then cooled to 20° C. to obtain a mixed system C. The mixed system C was subjected to solid-liquid separation to obtain sodium sulfate and ammonium sulfate crystals.

[0043] Example 5

[0044] 5kg electrolytic manganese slag, 0.5kg potassium hydroxide and 2kg potassium bicarbonate were weighed and placed in a reaction tank, 25L water was added, the water bath temperature was adjusted to 60°C, and the mixture was stirred for 60min at a stirring speed of 100r / min to make it uniform, thereby obtaining a mixed system A. Then, the mixed system A was subjected to solid-liquid separation, the pH of the leaching solution was 8.2, and the calculated sulfur leaching rate was 93.24%. After the leached slag was washed with countercurrent water three times, the potassium content in the slag was measured to be as low as 0.79%, and the ammonia nitrogen concentration was 8.77mg / L, reaching the first-level A standard of GB8978-1996 standard. After the leaching solution was evaporated and crystallized at 100°C, it was cooled to 40°C to obtain a mixed system B, and the mixed system B was subjected to solid-liquid separation, and the obtained potassium sulfate solid purity was 99.19%. After 10 cycles, an enriched solution E was obtained, which was evaporated and crystallized at 150° C. and then cooled to 20° C. to obtain a mixed system C. The mixed system C was subjected to solid-liquid separation to obtain sodium sulfate and ammonium sulfate crystals.

[0045] Example 6

[0046] 5kg electrolytic manganese slag, 0.5kg potassium hydroxide and 2kg potassium bicarbonate were weighed and placed in a reaction tank, 25L water was added, the water bath temperature was adjusted to 70°C, and the mixture was stirred for 60min at a stirring speed of 100r / min to make it uniform, thereby obtaining a mixed system A. Then, the mixed system A was subjected to solid-liquid separation, the pH of the leaching solution was 8.1, and the calculated sulfur leaching rate was 94.56%. After the leached slag was washed with countercurrent water three times, the potassium content in the slag was measured to be as low as 0.80%, and the ammonia nitrogen concentration was 8.21mg / L, reaching the first-level A standard of GB8978-1996 standard. After the leaching solution was evaporated and crystallized at 100°C, it was cooled to 40°C to obtain a mixed system B, and the mixed system B was subjected to solid-liquid separation, and the obtained potassium sulfate solid purity was 99.22%. After 10 cycles, an enriched solution E was obtained, which was evaporated and crystallized at 150° C. and then cooled to 20° C. to obtain a mixed system C. The mixed system C was subjected to solid-liquid separation to obtain sodium sulfate and ammonium sulfate crystals.

[0047] Example 7

[0048] 5kg electrolytic manganese slag, 0.5kg potassium hydroxide and 2kg potassium bicarbonate were weighed and placed in a reaction tank, 25L water was added, the water bath temperature was adjusted to 50°C, and the mixture was stirred for 120min at a stirring speed of 100r / min to make it uniformly stirred to obtain a mixed system A. Then, the mixed system A was subjected to solid-liquid separation, the pH of the leaching solution was 8.3, and the calculated sulfur leaching rate was 93.56%. After the leached slag was washed with countercurrent water three times, the potassium content in the slag was measured to be as low as 0.81%, and the ammonia nitrogen concentration was 8.14mg / L, reaching the first-level A standard of GB8978-1996 standard. After the leaching solution was evaporated and crystallized at 100°C, it was cooled to 40°C to obtain a mixed system B, and the mixed system B was subjected to solid-liquid separation, and the obtained potassium sulfate solid purity was 99.26%. After 10 cycles, an enriched solution E was obtained, which was evaporated and crystallized at 150° C. and then cooled to 20° C. to obtain a mixed system C. The mixed system C was subjected to solid-liquid separation to obtain sodium sulfate and ammonium sulfate crystals.

[0049] Example 8

[0050] 5kg electrolytic manganese slag, 0.5kg potassium hydroxide and 2kg potassium bicarbonate were weighed and placed in a reaction tank, 25L water was added, the water bath temperature was adjusted to 50°C, and the mixture was stirred for 240min at a stirring speed of 100r / min to make it uniform, thereby obtaining a mixed system A. Then, the mixed system A was subjected to solid-liquid separation, the pH of the leaching solution was 8.3, and the calculated sulfur leaching rate was 95.04%. After the leached slag was washed with countercurrent water three times, the potassium content in the slag was measured to be as low as 0.78%, and the ammonia nitrogen concentration was 8.09mg / L, reaching the first-level A standard of GB8978-1996 standard. After the leaching solution was evaporated and crystallized at 100°C, it was cooled to 40°C to obtain a mixed system B, and the mixed system B was subjected to solid-liquid separation, and the obtained potassium sulfate solid purity was 99.41%. After 10 cycles, an enriched solution E was obtained, which was evaporated and crystallized at 150° C. and then cooled to 20° C. to obtain a mixed system C. The mixed system C was subjected to solid-liquid separation to obtain sodium sulfate and ammonium sulfate crystals.

[0051] Example 9

[0052] 5kg electrolytic manganese slag, 0.5kg potassium hydroxide and 2kg potassium bicarbonate were weighed and placed in a reaction tank, 25L water was added, the water bath temperature was adjusted to 50°C, and the mixture was stirred for 240min at a stirring speed of 100r / min to make it uniformly stirred to obtain a mixed system A. Then, the mixed system A was subjected to solid-liquid separation, the pH of the leaching solution was 8.2, and the calculated sulfur leaching rate was 95.04%. After the leached slag was washed with countercurrent water 5 times, the potassium content in the slag was measured to be as low as 0.45%, and the ammonia nitrogen concentration was 6.10mg / L, reaching the first-level A standard of GB8978-1996 standard. After the leaching solution was evaporated and crystallized at 100°C, it was cooled to 40°C to obtain a mixed system B, and the mixed system B was subjected to solid-liquid separation, and the obtained potassium sulfate solid purity was 99.45%. After 10 cycles, an enriched solution E was obtained, which was evaporated and crystallized at 150° C. and then cooled to 20° C. to obtain a mixed system C. The mixed system C was subjected to solid-liquid separation to obtain sodium sulfate and ammonium sulfate crystals.

[0053] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0054] In addition, it should be noted that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0055] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate, characterized in that: The following methods are included: Step 100: adding electrolytic manganese slag and potassium salt into a reaction tank, and adding water into the reaction tank, the electrolytic manganese slag and potassium salt react under stirring conditions, and after the reaction is completed, performing solid-liquid separation on the product to obtain leaching slag A and leaching liquid A, wherein the mass ratio of the electrolytic manganese slag to the potassium salt is 1:0.1 to 1:1; Step 200: the leachate A is mixed with the electrolytic manganese slag to be treated, and potassium salt is added to the mixed solution so that the mass ratio of the electrolytic manganese slag to the potassium salt is 1:0.1 to 1:

1. After the reaction is completed, the product is subjected to solid-liquid separation to obtain the leachate slag A and the enriched concentrated solution B; Step 300: counter-currently washing the leached residue A obtained in step 100 and step 200 to obtain washed residue B, which is used for resource utilization; Step 400: evaporating and crystallizing the concentrated solution B obtained in step 200, cooling and filtering to obtain a potassium sulfate product, which is used for resource utilization; Step 500: The solution C obtained by evaporation and crystallization in step 400 is circulated for multiple times to generate an enriched solution E, and the enriched solution E is evaporated and crystallized, cooled and filtered to obtain ammonium sulfate and sodium sulfate crystals, and the ammonium sulfate and sodium sulfate are used for resource utilization.

2. The method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate according to claim 1, characterized in that: The solution C obtained by evaporation and crystallization in step 400 and the solution F obtained by evaporation and crystallization in step 500 are used to mix with the electrolytic manganese slag to be treated; The distilled water obtained by evaporation and crystallization in step 400 and step 500 is used for countercurrent washing in step 300; The high-concentration washing liquid D obtained by countercurrent washing in step 300 is used to mix with the electrolytic manganese slag to be treated.

3. The method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate according to claim 1 or 2, characterized in that: The mass ratio of electrolytic manganese slag to potassium salt is 1:0.5 to 1:

1.

4. The method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate according to claim 1 or 2, characterized in that: The potassium salt is potassium carbonate and / or potassium bicarbonate; Alternatively, the potassium salt is a complex of potassium hydroxide and potassium bicarbonate and / or potassium carbonate.

5. The method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate according to claim 4, characterized in that: In step 100, the reaction pH is 7-12.

6. The method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate according to claim 4, characterized in that: In step 100, the reaction temperature is 25°C to 80°C, the reaction time is 30 to 240 min, and the stirring speed is 10 to 200 r / min.

7. The method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate according to claim 4, characterized in that: In step 100, the solid-liquid ratio of electrolytic manganese slag to water is 1:3 to 1:

7.

8. The method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate according to claim 1 or 2, characterized in that: In step 300, the leached residue A is countercurrently washed 1 to 5 times.

9. The method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate according to claim 1 or 2, characterized in that: In step 400, the temperature of evaporation and crystallization is 50°C to 200°C, and the temperature of cooling is 0°C to 50°C.

10. The method for wet desulfurization of electrolytic manganese slag and separation and recycling of leachate according to claim 1 or 2, characterized in that: In step 500, the temperature of evaporation and crystallization is 50°C to 200°C, and the temperature of cooling is 0°C to 50°C.

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