A method for extracting manganese from electrolytic manganese slag

Abstract

The present invention provides a method for extracting manganese from electrolytic manganese slag, comprising the steps of: S1, ball-milling the electrolytic manganese slag, pyrite, and a leaching agent to obtain a ball-milled product; wherein the electrolytic manganese slag includes one or more of silicon dioxide and calcium sulfate dihydrate; the electrolytic manganese slag contains tetravalent manganese encapsulated in the silicon dioxide and / or calcium sulfate dihydrate; the mass ratio of the pyrite to the electrolytic manganese slag is no more than 5%; the ball milling speed is no less than 200 rpm, and the ball milling time is no less than 30 minutes; S2, solid-liquid separation of the ball-milled product to obtain a manganese-containing extract. The present invention has a high manganese leaching rate and does not cause large-scale leaching of iron.

Description

Technical Field

[0001] The present invention relates to the fields of environmental engineering and solid waste resource utilization, and in particular to a method for extracting manganese from electrolytic manganese slag. Background Art

[0002] Manganese is widely used in industries such as steel production, non-ferrous metal smelting and battery manufacturing, and is an important basic material that is indispensable to the national economy. At present, the production of manganese metal is mainly through electrolysis. Electrolytic manganese slag is an industrial solid waste generated during the production of electrolytic manganese metal after manganese ore undergoes acid leaching, neutralization and filter pressing. Electrolytic manganese slag contains a large amount of heavy metal ions, soluble salts and other solid mineral components, such as sulfate, ammonia nitrogen and water-soluble Mn. 2+ and other harmful substances.

[0003] With the increasing depletion of manganese ore resources and the continuous decline in manganese ore grade, the production of one ton of electrolytic manganese results in the discharge of up to 10 to 15 tons of electrolytic manganese slag, further exacerbating the difficulty and environmental pressure of electrolytic manganese slag disposal. During long-term storage, the manganese in electrolytic manganese slag migrates into surrounding surface water, groundwater, and soil, causing serious pollution to the local environment. Although manganese is an essential trace element for organisms, excessive manganese is toxic to organisms and the environment. Therefore, extracting manganese from electrolytic manganese slag can not only alleviate the environmental pollution caused by electrolytic manganese slag, but also bring significant economic benefits to electrolytic manganese enterprises.

[0004] In view of this, it is necessary to provide a method for extracting manganese from electrolytic manganese slag to solve or at least alleviate the above-mentioned technical defects in how to effectively extract manganese from electrolytic manganese slag. Summary of the Invention

[0005] The main purpose of the present invention is to provide a method for extracting manganese from electrolytic manganese slag, aiming to solve the above-mentioned technical problem of how to effectively extract manganese from electrolytic manganese slag.

[0006] To achieve the above object, the present invention provides a method for extracting manganese from electrolytic manganese slag, comprising the steps of:

[0007] S1, ball-milling the electrolytic manganese slag, pyrite and leaching agent to obtain a ball-milled product;

[0008] Wherein, the mass ratio of the pyrite to the electrolytic manganese slag is not higher than 5%;

[0009] The ball milling speed is not less than 200 rpm, and the ball milling time is not less than 30 min;

[0010] S2, performing solid-liquid separation on the ball-milled product to obtain a manganese-containing extract.

[0011] Furthermore, the electrolytic manganese slag includes one or more of silicon dioxide and calcium sulfate dihydrate; the electrolytic manganese slag contains tetravalent manganese wrapped in the silicon dioxide and / or the calcium sulfate dihydrate.

[0012] Furthermore, the leaching agent includes water.

[0013] Furthermore, the mass volume ratio of the electrolytic manganese slag to the leaching agent is 1g:10-30mL.

[0014] Furthermore, during the ball milling process, the ball-to-material ratio of the ball milling beads to the electrolytic manganese slag is 5 to 50:1.

[0015] Furthermore, during the ball milling process, the ball-to-material ratio of the ball milling beads to the electrolytic manganese slag is 20:1.

[0016] Furthermore, the mass ratio of the pyrite to the electrolytic manganese slag is 1 to 5%.

[0017] Furthermore, the ball milling speed is 200-500 rpm, and the ball milling time is 30-180 min.

[0018] Furthermore, the step S1 further comprises: grinding the electrolytic manganese slag and the pyrite before ball-milling the electrolytic manganese slag, the pyrite and the leaching agent together.

[0019] Furthermore, the grinding includes: grinding the electrolytic manganese slag and the pyrite to a particle size of no more than 80 meshes.

[0020] Compared with the prior art, the present invention has at least the following advantages:

[0021] The present invention provides a method for extracting manganese from electrolytic manganese slag, which has a high manganese leaching rate and does not cause a large amount of iron leaching. Specifically, the present invention uses ball milling as a reaction condition to promote the release of manganese in the entrained and embedded state, generate a new reaction interface, and increase the specific surface area of ​​the reaction; the present invention uses pyrite as a reactant, and pyrite can be activated under the conditions of ball milling to make Fe 2+ and S2 2- The manganese is activated to participate in the reaction, thereby promoting the conversion of manganese into a glassy phase with poor crystal form and discrete state; the present invention uses water as a leaching agent, which can not only directly elute the manganese in the glassy phase, but also avoid the use of acid; in addition, the pH value of the ball milling process can be maintained at 4.5-5.5, so that Fe 3+ Complexes are difficult to form, thus ensuring the selective extraction of poorly soluble manganese. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 the structures shown in these drawings without paying any creative work.

[0023] Figure 1 The scanning electron microscope microscopic images of the original electrolytic manganese slag (a), the residue after ball milling (b), and the residue after pyrite and ball milling (c) in the present invention;

[0024] Figure 2 TIMA phase composition analysis diagram of electrolytic manganese slag in the present invention;

[0025] Figure 3 is the XRD pattern of the electrolytic manganese slag in the present invention;

[0026] Figure 4 This is the XRF element content diagram of the electrolytic manganese slag in the present invention;

[0027] Figure 5 The figure is a graph showing the total manganese content and the valence state distribution of ICP in the electrolytic manganese slag of the present invention;

[0028] Figure 6 The data effect diagram of manganese leaching rate, manganese reduction rate and iron leaching rate under different pyrite addition amounts in Example 1 of the present invention;

[0029] Figure 7 The data effect diagram of manganese leaching rate, manganese reduction rate and iron leaching rate at different ball milling speeds in Example 2 of the present invention;

[0030] Figure 8 The data effect diagram of manganese leaching rate, manganese reduction rate and iron leaching rate at different ball milling times in Example 3 of the present invention;

[0031] Figure 9 This is a data effect diagram of manganese leaching rate, manganese reduction rate and iron leaching rate under different ball-to-material ratios in Example 4 of the present invention.

[0032] The realization of the objectives, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 any creative efforts are within the scope of protection of the present invention.

[0034] Moreover, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] When numerical ranges are given in the examples, it should be understood that unless otherwise specified herein, both endpoints of each numerical range and any value between the two endpoints may be used. Unless otherwise defined, all technical and scientific terms used herein are consistent with the prior art as understood by those skilled in the art and the description of the present invention. Any prior art methods, devices, and materials similar or equivalent to those described in the examples of the present invention may also be used to implement the present invention.

[0036] The present invention provides a method for extracting manganese from electrolytic manganese slag, comprising the steps of:

[0037] S1, ball-milling the electrolytic manganese slag, pyrite and leaching agent to obtain a ball-milled product.

[0038] The leaching agent may include or be the water, and acid leaching treatment may not be required.

[0039] The electrolytic manganese slag may include or be industrial solid waste generated after acid leaching, neutralization, and filter pressing of pyrolusite in the electrolytic manganese metal production process.

[0040] It should be noted that the manganese in the electrolytic manganese slag mainly exists in the form of divalent manganese and tetravalent manganese, that is, the electrolytic manganese slag contains tetravalent manganese; and the manganese in the electrolytic manganese slag exists in the form of physical phase wrapping.

[0041] Specifically, during the long-term stacking process, the particles of the electrolytic manganese slag gradually condense into hard blocks, the soluble divalent manganese is gradually oxidized into tetravalent manganese, and the manganese-containing phase is wrapped by gangue minerals such as silica and calcium sulfate dihydrate, making it difficult to leach and extract the manganese element in the electrolytic manganese slag using traditional leaching methods.

[0042] For example, in the prior art, conventional water leaching, at a solid-to-liquid ratio of 1:4 (g / ml), a temperature of 24°C, and a stirring speed of 300 r / min, can achieve a soluble manganese leaching rate of 83.35%. However, this method only leaches soluble manganese and fails to effectively leach insoluble manganese. Furthermore, a low-temperature roasting-water leaching method, using electrolytic manganese slag with a solid-to-liquid ratio of 1:4 (g / ml), maintained at 600°C for 60 minutes, only yielded a total manganese leaching rate of 67.45%. Due to the presence of insoluble manganese, a large amount of manganese cannot be extracted.

[0043] Based on the source and characteristics of the electrolytic manganese slag, the electrolytic manganese slag includes one or more of silicon dioxide and calcium sulfate dihydrate, and the electrolytic manganese slag contains manganese wrapped or doped in the silicon dioxide and / or the calcium sulfate dihydrate. The manganese may include or be insoluble tetravalent manganese, and the manganese may also include divalent manganese and tetravalent manganese at the same time.

[0044] In order to achieve efficient and selective extraction of manganese from electrolytic manganese slag, the present invention wet-ball-mills the electrolytic manganese slag and the pyrite, thereby efficiently and selectively reducing tetravalent manganese to divalent manganese and ensuring the release of manganese.

[0045] The mass ratio of the pyrite to the electrolytic manganese slag is not higher than 5%; preferably, the mass ratio may be 1-5%, specifically 4%; the mass ratio may be understood as the mass percentage of the pyrite to the electrolytic manganese slag.

[0046] The ball milling speed is not less than 200 rpm, and the ball milling time is not less than 30 min; further, the ball milling speed can be 200-500 rpm, and the ball milling time can be 30-180 min.

[0047] The mass volume ratio of the electrolytic manganese slag to the leaching agent is 1g:10-30mL.

[0048] During the ball milling process, the ball-to-material ratio of the ball milling beads to the electrolytic manganese slag is 5 to 50:1. Preferably, the ball-to-material ratio of the ball milling beads to the electrolytic manganese slag is 20:1.

[0049] It should also be noted that before the electrolytic manganese slag, the pyrite and the leaching agent are ball-milled together, the electrolytic manganese slag and the pyrite can be ground to a particle size of no more than 80 mesh; the grinding of the electrolytic manganese slag and the pyrite can be carried out separately.

[0050] S2, performing solid-liquid separation on the ball-milled product to obtain a manganese-containing extract and a manganese-removed slag.

[0051] It should be noted that the present invention achieves efficient leaching of manganese from manganese electrolytic slag, with a leaching rate of about 90%; and the pH of the mixture to be ball-milled is 4.5-5.5, Fe 3+ Complexes are difficult to form, and iron preferentially forms hydroxyl iron and other substances under extremely weak acidic pH conditions, which are difficult to leach. Therefore, in addition to being able to extract manganese, the present invention can also avoid the leaching of iron, thereby achieving selective extraction of manganese.

[0052] In the present invention, manganese is selectively recovered and utilized from electrolytic manganese slag by a pyrite-assisted mechanical ball milling method, and tetravalent manganese can be efficiently reduced to divalent manganese, so that the leaching rate of manganese is significantly improved.

[0053] In addition, based on pyrite, wet ball milling is used as a reaction condition. By moving ball milling beads at high speed to mill gangue minerals such as silica and calcium sulfate dihydrate and the manganese-containing phases contained therein, uniform mixing of pyrite, electrolytic manganese slag and water can be achieved. At the same time, the ball milling process has the effect of activating pyrite and reducing the particle size of electrolytic manganese. During repeated ball milling, tetravalent manganese is reduced to divalent manganese under the reducing effect of pyrite.

[0054] Specifically, on the one hand, ball milling can reduce the particle size of the material, and the manganese-containing phase is easy to form a glass phase with poor crystal form and discrete state. The collision releases the manganese in the entrapped and embedded state, providing a reaction interface. On the other hand, the collision generates great kinetic energy, which is converted into heat energy to activate pyrite. 2+ and S2 2- It is activated to participate in the reaction, and after reduction, divalent manganese is washed out by water.

[0055] To facilitate understanding by those skilled in the art, examples are given below (all experiments provided in the embodiments of the present invention were conducted at room temperature):

[0056] Example 1

[0057] To explore the effect of different pyrite addition amounts on manganese slag leaching, the specific treatment steps are as follows:

[0058] 1. Crush and dry the electrolytic manganese slag, grind it and pass it through an 80-mesh standard sieve, and take the sieve underflow for later use; crush and dry the pyrite, grind it and pass it through an 80-mesh standard sieve, and take the sieve underflow for later use.

[0059] 2. Weigh 5g of ground electrolytic manganese slag and 100g of ball milling beads at a ball-to-material ratio of 20:1;

[0060] The ground pyrite was weighed according to 0%, 1%, 2%, 3%, 4%, and 5% of the mass of the electrolytic manganese slag, that is, 0 g, 50 mg, 100 mg, 150 mg, 200 mg, and 250 mg of pyrite were weighed respectively; wherein, the weighing amounts of the above 6 types of pyrite correspond to 6 tests, and each test uses one of the weighing amounts.

[0061] 3. In a single test, the weighed ball mill beads, electrolytic manganese slag, and pyrite were placed in a zirconia ball mill, and 100 ml of deionized water was added to obtain a mixture; then, the mixture was ball milled at a ball milling speed of 300 rpm for 2 h. After the ball milling, the solid-liquid separation was performed to obtain a manganese-containing leachate and a residue.

[0062] In this embodiment, the electrolytic manganese slag is derived from: during the production of electrolytic manganese metal, pyrolusite, whose main component is manganese dioxide, is subjected to acid leaching, neutralization, and filter pressing to produce filter residue; the electrolytic manganese slag contains a certain amount of tetravalent manganese, soluble manganese, etc., and the mineral phase composition is complex.

[0063] Reference Figure 1 As shown in part (a), the raw, untreated electrolytic manganese slag contains numerous dense, smooth columnar structures. Direct leaching makes it difficult to access internal interfaces. The present invention, using ball milling as a reaction condition, breaks them up and exposes them, creating new reaction interfaces and increasing the specific surface area for reaction.

[0064] Reference Figure 2 As shown in the figure, it can be seen that the main components of electrolytic manganese slag are quartz and calcite, with a small amount of pyrite and biotite. Manganese mainly forms iron-manganese-silicon oxide with iron and silicon or is coated by quartz. The stable physical and chemical properties of quartz increase the difficulty of manganese leaching.

[0065] like Figure 3 As shown, it can be seen that the electrolytic manganese slag contains gypsum-CaSO4·2H2O, quartz-SiO2, manganese sulfate-MnSO4·H2O, pyrite-FeS2, jarosite-KFe3(SO4)2(OH)6, pyrolusite-MnO2, and pyrolusite-(Ca,Mn)Mn4O9·3H2O.

[0066] Electrolytic manganese slag is primarily composed of quartz (SiO2, PDF#46-1045) and calcium sulfate dihydrate (CaSO4·2H2O, PDF#33-0311). In addition, soluble manganese salts (such as manganese sulfate) and other insoluble manganese-containing minerals are present. The manganese-containing phases are encapsulated by gangue minerals such as silica and calcium sulfate dihydrate, making it difficult to extract the manganese element from the electrolytic manganese slag using traditional leaching methods.

[0067] Reference Figure 4 As shown, it can be seen that through XRF element analysis, the mass content of Fe in the electrolytic manganese slag is 8.86%, and the mass content of Mn is 6.04%.

[0068] Reference Figure 5As shown, it can be seen that the total manganese content measured by ICP is 2.488%, of which the mass proportion of tetravalent manganese in the manganese element is 48.07%, and the mass proportion of divalent manganese in the manganese element is 51.03% (the subsequent data of the present invention are all based on the ICP results).

[0069] The test results of this embodiment refer to Figure 6 As shown:

[0070] When the mass of pyrite is 0% of the electrolytic manganese slag, the manganese leaching rate is 64.66%, the reduction rate of tetravalent manganese is 64.69%, and the iron leaching rate is 0.00%;

[0071] When the mass of pyrite is 1% of the electrolytic manganese slag, the manganese leaching rate is 72.89%, the reduction rate of tetravalent manganese is 74.85%, and the iron leaching rate is 0.00%;

[0072] When the mass of pyrite is 2% of the electrolytic manganese slag, the manganese leaching rate is 74.80%, the reduction rate of tetravalent manganese is 77.80%, and the iron leaching rate is 0.05%;

[0073] When the mass of pyrite is 3% of the electrolytic manganese slag, the manganese leaching rate is 79.62%, the reduction rate of tetravalent manganese is 83.01%, and the iron leaching rate is 0.15%;

[0074] When the mass of pyrite is 4% of the electrolytic manganese slag, the manganese leaching rate is 81.60%, the reduction rate of tetravalent manganese is 87.39%, and the iron leaching rate is 0.39%;

[0075] When the mass of pyrite is 5% of the electrolytic manganese slag, the manganese leaching rate is 78.02%, the reduction rate of tetravalent manganese is 88.62%, and the iron leaching rate is 0.55%.

[0076] Example 2

[0077] To explore the effect of different ball milling speeds on manganese slag leaching, the specific processing steps are as follows:

[0078] 1. The electrolytic manganese slag (same as in Example 1) was crushed and dried, and after grinding, it was passed through an 80-mesh standard sieve, and the undersize was set aside; the pyrite was crushed and dried, and after grinding, it was passed through an 80-mesh standard sieve, and the undersize was set aside.

[0079] 2. Weigh 5 g of ground electrolytic manganese slag and 100 g of ball mill beads at a ball-to-material ratio of 20:1; weigh 4% of the mass of the ground pyrite, i.e., weigh 200 mg of pyrite.

[0080] 3. Place the weighed ball mill beads, electrolytic manganese slag, and pyrite into a zirconia ball mill, and add 100 ml of deionized water to obtain a mixture; then, ball mill the mixture at a set ball milling speed for 2 hours. After the ball milling is completed, the solid and liquid are separated to obtain a manganese-containing leachate and a residue.

[0081] The ball milling speeds set above are 0 rpm (stationary), 100 rpm, 200 rpm, 300 rpm, 400 rpm, and 500 rpm, respectively. The above 6 ball milling speeds correspond to 6 tests, and each test uses one of the ball milling speeds.

[0082] The test results of this embodiment refer to Figure 7 As shown:

[0083] When the ball milling speed was 0 rpm, the leaching rate of manganese was 45.51%, the reduction rate of tetravalent manganese was 38.35%, and the leaching rate of iron was 0.22%.

[0084] When the ball milling speed was 100 rpm, the leaching rate of manganese was 62.34%, the reduction rate of tetravalent manganese was 60.83%, and the leaching rate of iron was 0.25%.

[0085] When the ball milling speed was 200 rpm, the leaching rate of manganese was 73.52%, the reduction rate of tetravalent manganese was 80.38%, and the leaching rate of iron was 0.37%.

[0086] When the ball milling speed was 300 rpm, the leaching rate of manganese was 82.43%, the reduction rate of tetravalent manganese was 87.09%, and the leaching rate of iron was 0.53%.

[0087] When the ball milling speed was 400 rpm, the leaching rate of manganese was 85.25%, the reduction rate of tetravalent manganese was 88.85%, and the leaching rate of iron was 0.65%.

[0088] When the ball milling speed is 500 rpm, the leaching rate of manganese is 92.86%, the reduction rate of tetravalent manganese is 91.70%, and the leaching rate of iron is 0.92%.

[0089] Example 3

[0090] To explore the effect of different ball milling times on manganese slag leaching, the specific processing steps are as follows:

[0091] 1. The electrolytic manganese slag (same as in Example 1) was crushed and dried, and after grinding, it was passed through an 80-mesh standard sieve, and the undersize was set aside; the pyrite was crushed and dried, and after grinding, it was passed through an 80-mesh standard sieve, and the undersize was set aside.

[0092] 2. Weigh 5 g of ground electrolytic manganese slag and 100 g of ball mill beads at a ball-to-material ratio of 20:1; weigh 4% of the mass of the ground pyrite, i.e., weigh 200 mg of pyrite.

[0093] 3. Place the weighed ball milling beads, electrolytic manganese slag, and pyrite into a zirconia ball mill jar, and add 100 ml of deionized water to obtain a mixture; then, ball mill the mixture at a ball milling speed of 300 rpm for a set ball milling time. After the ball milling is completed, solid-liquid separation is performed to obtain a manganese-containing leachate and a residue.

[0094] Among them, the above-mentioned ball milling times are set to 30 min, 60 min, 90 min, 120 min, 150 min, and 180 min respectively; the above 6 ball milling times correspond to 6 tests, and each test uses one of the ball milling times.

[0095] The test results of this embodiment refer to Figure 8 As shown:

[0096] When the ball milling time was 30 min, the leaching rate of manganese was 73.97%, the reduction rate of tetravalent manganese was 66.63%, and the leaching rate of iron was 0.26%.

[0097] When the ball milling time was 60 min, the leaching rate of manganese was 78.70%, the reduction rate of tetravalent manganese was 73.95%, and the leaching rate of iron was 0.38%.

[0098] When the ball milling time was 90 min, the leaching rate of manganese was 79.58%, the reduction rate of tetravalent manganese was 81.61%, and the leaching rate of iron was 0.39%.

[0099] When the ball milling time was 120 min, the leaching rate of manganese was 82.42%, the reduction rate of tetravalent manganese was 87.95%, and the leaching rate of iron was 0.47%.

[0100] When the ball milling time was 150 min, the leaching rate of manganese was 84.11%, the reduction rate of tetravalent manganese was 89.55%, and the leaching rate of iron was 0.81%.

[0101] When the ball milling time was 180 min, the leaching rate of manganese was 85.56%, the reduction rate of tetravalent manganese was 92.96%, and the leaching rate of iron was 0.89%.

[0102] Example 4

[0103] To explore the effect of different ball-to-material ratios on manganese slag leaching, the specific processing steps are as follows:

[0104] 1. The electrolytic manganese slag (same as in Example 1) was crushed and dried, and after grinding, it was passed through an 80-mesh standard sieve, and the undersize was set aside; the pyrite was crushed and dried, and after grinding, it was passed through an 80-mesh standard sieve, and the undersize was set aside.

[0105] 2. Weigh 5 g of the ground electrolytic manganese slag and a preset mass of ball mill beads; weigh 4% of the mass of the ground pyrite, that is, weigh 200 mg of pyrite.

[0106] Among them, the above preset masses are 25g, 50g, 100g, 150g, 200g, and 250g, corresponding to ball-to-material ratios of 5:1, 10:1, 20:1, 30:1, 40:1, and 50:1, respectively; the above 6 preset masses correspond to 6 tests, and each test uses one of the masses.

[0107] 3. Place the weighed ball milling beads, electrolytic manganese slag, and pyrite into a zirconia ball mill jar, and add 100 ml of deionized water to obtain a mixture; then, ball mill the mixture for 2 hours at a ball milling speed of 300 rpm. After the ball milling is completed, the solid-liquid separation is performed to obtain a manganese-containing leachate and a residue.

[0108] The test results of this embodiment refer to Figure 9 As shown:

[0109] When the ball-to-material ratio is 5:1, the leaching rate of manganese is 77.86%, the reduction rate of tetravalent manganese is 87.26%, and the leaching rate of iron is 0.85%.

[0110] When the ball-to-material ratio is 10:1, the manganese leaching rate is 77.58%, the reduction rate of tetravalent manganese is 87.43%, and the iron leaching rate is 0.77%.

[0111] When the ball-to-material ratio is 20:1, the leaching rate of manganese is 81.61%, the reduction rate of tetravalent manganese is 89.51%, and the leaching rate of iron is 0.54%.

[0112] When the ball-to-material ratio is 30:1, the manganese leaching rate is 76.52%, the reduction rate of tetravalent manganese is 88.57%, and the iron leaching rate is 0.59%.

[0113] When the ball-to-material ratio is 40:1, the manganese leaching rate is 76.76%, the reduction rate of tetravalent manganese is 87.57%, and the iron leaching rate is 0.61%.

[0114] When the ball-to-material ratio is 50:1, the manganese leaching rate is 79.20%, the reduction rate of tetravalent manganese is 87.76%, and the iron leaching rate is 0.88%.

[0115] Analysis example 1

[0116] See also Figure 1As shown, the original electrolytic manganese slag, the residue after ball milling treatment (corresponding to the residue obtained by the treatment test in which the amount of pyrite added in Example 1 is 0), and the residue after the treatment of pyrite and ball milling (corresponding to the residue obtained by the treatment test in which the amount of pyrite added in Example 1 is 200 mg) are compared.

[0117] It can be seen that:

[0118] Before treatment, the dense gypsum in the original electrolytic manganese slag covers the manganese-containing phase, forming a columnar structure with a smooth surface;

[0119] When ball milling alone is used, the smooth surface of the residue is destroyed by the collision of the ball mill, and broken blocks appear on the surface, which promotes the release of the entrained and embedded manganese to the new reaction interface.

[0120] When pyrite and ball milling are used together for treatment, the block surface of the residue produced by ball milling reacts with pyrite and leaches, and the exposed manganese-containing phase is converted into a glass phase with poor crystal form and discrete state. Tetravalent manganese is reduced and leached, and the surface appears to be attached with particles.

[0121] Analysis example 2

[0122] 1. The pH of the mixture corresponding to the addition of 0%, 2% and 4% pyrite in Example 1 was measured.

[0123] Before ball milling, the pH values ​​of the mixture corresponding to the addition of 0%, 2% and 4% pyrite were 5.63, 5.27 and 4.85 respectively; after ball milling for 1 hour (note: the ball milling time is different from that in Example 1, and other conditions are the same), the pH values ​​of the mixture corresponding to the addition of 0%, 2% and 4% pyrite were 5.56, 5.39 and 5.07 respectively; this indicates that the present invention can maintain the pH value of the mixture at 4.5 to 5.5 before and after ball milling, so that the Fe 3+ Complexes are difficult to form.

[0124] 2. The pH of the mixture corresponding to the ball milling speeds of 100 rpm, 300 rpm, and 500 rpm in Example 2 was measured.

[0125] Before ball milling, the pH values ​​of the mixture corresponding to the ball milling speeds of 100 rpm, 300 rpm, and 500 rpm were 5.06, 5.24, and 4.88, respectively (the mixtures were prepared separately in three experiments); after ball milling for 1 hour (note: the ball milling time was different from that in Example 2, and other conditions were the same), the pH values ​​of the mixture corresponding to the ball milling speeds of 100 rpm, 300 rpm, and 500 rpm were 5.38, 5.38, and 4.92, respectively; this indicates that the present invention can maintain the pH value of the mixture at 4.5 to 5.5 before and after ball milling, so that Fe 3+ Complexes are difficult to form.

[0126] The above technical solutions of the present invention are only preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention's description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for extracting manganese from electrolytic manganese slag, characterized in that: Including steps: S1, ball-milling the electrolytic manganese slag, pyrite and leaching agent to obtain a ball-milled product; maintaining the pH value at 4.5-5.5 during the ball-milling process; The leaching agent is water, and no acid leaching treatment is required; the mass volume ratio of the electrolytic manganese slag to the leaching agent is 1g:10~30mL; The electrolytic manganese slag contains tetravalent manganese and soluble manganese; the electrolytic manganese slag contains gypsum (CaSO4·2H2O), quartz (SiO2), manganese sulfate (MnSO4·H2O), pyrite (FeS2), jarosite (KFe3(SO4)2(OH)6), pyrolusite (MnO2), and phyllostachite; manganese elements form iron-manganese-silicon oxide with iron and silicon elements or are coated by quartz; The mass ratio of the pyrite to the electrolytic manganese slag is 1-5%; the ball milling speed is not less than 200 rpm, and the ball milling time is not less than 30 minutes; S2, performing solid-liquid separation on the ball-milled product to obtain a manganese-containing extract.

2. The method for extracting manganese from electrolytic manganese slag according to claim 1, characterized in that: During the ball milling process, the ball-to-material ratio of the ball milling beads to the electrolytic manganese slag is 5-50:

1.

3. The method for extracting manganese from electrolytic manganese slag according to claim 2, characterized in that: During the ball milling process, the ball-to-material ratio of the ball milling beads to the electrolytic manganese slag is 20:

1.

4. The method for extracting manganese from electrolytic manganese slag according to claim 1, characterized in that: The ball milling speed is 200-500 rpm, and the ball milling time is 30-180 min.

5. The method for extracting manganese from electrolytic manganese slag according to any one of claims 1 to 4, characterized in that: The step S1 further includes: grinding the electrolytic manganese slag and the pyrite before ball-milling the electrolytic manganese slag, the pyrite and the leaching agent together.

6. The method for extracting manganese from electrolytic manganese slag according to claim 5, characterized in that: The grinding comprises: grinding the electrolytic manganese slag and the pyrite to a particle size of no more than 80 meshes.

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