Method for efficiently separating iron and manganese components in ferromanganese ore based on step-by-step leaching

Abstract

The invention relates to a method for efficiently separating iron and manganese components in ferromanganese ore based on step-by-step leaching, which comprises the following steps of: mixing the ferromanganese ore with an intermediate product or a vanadium product in the vanadium industry to obtain a mixed material, and roasting the mixed material at high temperature to obtain roasted clinker; the roasted clinker is subjected to primary leaching and secondary leaching, and manganese-containing leaching liquid and vanadium-containing and iron-containing leaching residues are obtained; the obtained manganese-containing leachate is subjected to precipitation or drying crystallization and filtration, and a manganese product and manganese extraction waste liquid are obtained; the vanadium-containing and iron-containing leaching residues are leached, the pH of a leaching system is controlled through an alkaline solution, filtering is conducted after leaching, and vanadium-containing leaching liquid and iron-containing leaching residues are obtained. By means of the method, efficient separation of iron and manganese in the ferromanganese ore is achieved, and efficient cyclic utilization of intermediate products or vanadium products in the vanadium industry is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of ferromanganese ore resource utilization, vanadium chemical technology and resource recycling, and specifically relates to a method for efficiently separating iron and manganese components in ferromanganese ore based on step-by-step leaching. Background Art

[0002] Manganese can be used in metallurgy, batteries, agriculture and other fields. It is a major scarce metal that maintains the national economy. The characteristics of my country's manganese ore resources are high iron impurity content and less high-grade manganese ore. Among the explored deposits, 73% of the iron content exceeds the standard. In order to promote the sustainable development of my country's manganese ore industry, it is urgent to improve the utilization rate of manganese resources.

[0003] Existing iron and manganese separation technologies mainly include mechanical separation, pyro separation and wet separation. Mechanical separation cannot achieve ideal technical and economic indicators due to the complex composition and fine embedded particle size of iron-manganese ore. Pyro separation requires coke as a reducing agent and smelting at high temperature, which has the characteristics of high energy consumption and high pollution. It is a common phenomenon for iron and manganese to be leached together in wet separation, which makes it more difficult to remove iron from manganese later.

[0004] A large number of studies have shown that compared with various existing separation technologies, the leaching method can obtain better separation indicators, with high resource utilization, simple operation and low energy consumption. However, the disadvantages of co-leaching of iron and manganese in traditional chemical leaching methods are often not solved, and the loss rate of the roasting medium is high. Therefore, a roasting medium with high selectivity for iron or manganese is sought, and under the condition of a low loss rate of the roasting medium, the mineral phase transformation of iron and manganese is promoted to achieve efficient separation of iron and manganese. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In order to solve the above problems in the prior art, the present invention proposes a method for efficiently separating iron and manganese components in ferromanganese ore based on step-by-step leaching. The method utilizes vanadium element to directional reconstruct and transform the insoluble manganese minerals in the ferromanganese ore into acid-soluble manganese vanadate, and regulates the physical phase of the iron minerals, and then leaches them out through acid solution to achieve efficient separation of the iron and manganese components and recycling of the roasting medium.

[0007] (II) Technical solution

[0008] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0009] A method for efficiently separating iron and manganese components in iron-manganese ore based on step-by-step leaching, comprising the following steps:

[0010] S1. Roasting: Mixing ferromanganese ore with an intermediate product of the vanadium industry or a vanadium product to obtain a mixed material, wherein the mixing ratio of the ferromanganese ore and the intermediate product of the vanadium industry or the vanadium product is calculated as n(MnO2) / n(V2O5), wherein MnO2 is manganese in the ferromanganese ore (calculated as MnO2), and V2O5 is vanadium in the vanadium product or the intermediate product of the vanadium industry or the vanadium product containing vanadium oxide (calculated as V2O5), and n(MnO2) / n(V2O5) is 0.5-3:1; roasting the mixed material at a high temperature to obtain a roasted clinker;

[0011] S2, primary leaching: leaching the roasted clinker obtained in step S1, using an acid solution to adjust the pH value of the leaching system to 2-3; in the actual roasting process, the vanadium element directional reconstructs and transforms the insoluble manganese minerals in the iron manganese ore into acid-soluble manganese vanadate, and regulates the physical phase of the iron minerals, and then leaching them out through the acid solution to achieve efficient separation of iron and manganese components and recycling of roasting media;

[0012] S3, secondary leaching: using sulfuric acid solution to continue to adjust the pH value to below 1.8, filtering after leaching, and obtaining manganese-containing leaching solution and vanadium-containing and iron-containing leaching residue;

[0013] S4, recovering manganese: precipitating or drying and crystallizing the manganese-containing leaching solution obtained in step S3, filtering, and obtaining a manganese product and a manganese extraction waste liquid;

[0014] S5, separation of vanadium and iron: leaching the vanadium-containing and iron-containing leaching residue obtained in step S3, using an alkaline solution to control the pH value of the leaching system to 7.0-14.0, filtering after leaching to obtain a vanadium-containing leaching solution and an iron-containing leaching residue.

[0015] The method as described above, preferably, further comprises:

[0016] S6, recovering vanadium: adding a vanadium precipitation additive to the vanadium-containing leaching solution obtained in step S5, and adjusting the pH value to 2-3 for vanadium precipitation, filtering after vanadium precipitation to obtain an intermediate product or vanadium product of the vanadium industry and vanadium extraction waste liquid; the recovered intermediate product or vanadium product of the vanadium industry can be directly output as a product, or can be recycled as a roasting additive;

[0017] S7. Utilization of vanadium industry intermediate products or vanadium products: the vanadium industry intermediate products or vanadium products obtained in step S6 are output as products, or the vanadium industry intermediate products or vanadium products are recycled back to the roasting system as additives to participate in the next round of roasting;

[0018] S8, utilization of iron-containing tailings: the iron-containing leached slag obtained in step S5 is used as a feed material for a blast furnace, or as a raw material for preparing ferroalloys; the iron-containing leached slag has a high iron content, which can reach the standard of iron concentrate (TFe>60%), and can be directly used as a raw material for blast furnace ironmaking, or as a raw material for preparing ferroalloys;

[0019] S9, waste liquid circulation: after impurities are removed from the manganese extraction waste liquid and the vanadium extraction waste liquid obtained in steps S4 and S6, they are circulated back to the leaching system as the leaching medium in step S2.

[0020] In the method as described above, preferably, in step S1, the ferromanganese ore is a manganese ore with a Mn / Fe mass ratio of less than 3, and may be at least one of an oxide mineral, a hydrogenated mineral, a carbonate mineral, a sulfide mineral, a silicate mineral and a borate mineral; and its particle size is 200-300 meshes.

[0021] Preferably, the intermediate product or vanadium product of the vanadium industry includes at least one of vanadate, vanadium oxide, vanadium slag, etc. Vanadium salts include polyvanadate, ammonium metavanadate, pyrovanadate, orthovanadate, etc., specifically including ammonium polyvanadate, ammonium metavanadate, sodium metavanadate, sodium pyrovanadate, sodium orthovanadate, calcium metavanadate, calcium pyrovanadate, calcium orthovanadate, manganese metavanadate, manganese pyrovanadate, manganese orthovanadate, etc. Vanadium oxide includes at least one of vanadium trioxide, vanadium dioxide, and vanadium pentoxide. Vanadium slag is an intermediate product obtained from the vanadium-titanium magnetite smelting process, and the vanadium content is 1-15% in terms of V2O5.

[0022] Preferably, in step S1, the high temperature calcination temperature is 700-1000°C, the constant temperature time is 10-300 min, and the heating rate is 2-10°C / min.

[0023] Preferably, in step S2, leaching is performed at a liquid-solid ratio of deionized water to roasted clinker of 2 to 20:1 mL / g, the leaching temperature is 80 to 100°C, and the leaching time is 60 to 180 minutes; the acid solution is at least one of sulfuric acid, hydrochloric acid or nitric acid; the leached residue is repeatedly washed with water having a pH value lower than 1.8 and a temperature of 20 to 100°C. Furthermore, the leaching can be performed in a water bath or a heating jacket.

[0024] Preferably, in step S4, the manganese precipitate is precipitated by carbonization precipitation or direct precipitation. The carbonization precipitation method is to add at least one of carbon dioxide gas, sodium carbonate solution and ammonium carbonate solution to the manganese-containing supernatant, wherein the carbon dioxide is pure carbon dioxide gas or industrial carbon dioxide, or flue gas containing carbon dioxide released when vanadium slag is mixed with calcium salt and manganese salt and roasted; during the carbonization process, the pH value of the carbonization system is maintained at 6-8 by adding an alkaline solution; the alkaline solution is at least one of sodium hydroxide solution, ammonia water, sodium carbonate and ammonium carbonate solution; the carbonization temperature is 20-100° C.; the carbonization time is 10-120 min; the manganese salt obtained by carbonization precipitation is manganese carbonate; the direct precipitation method is to add an alkaline substance to the manganese-containing supernatant to maintain the pH value of the precipitation system at 7-10, the alkaline substance is at least one of sodium hydroxide solution and ammonia water; the direct precipitation temperature is 20-100° C.; the precipitation time is 10-120 min; the manganese salt obtained by direct precipitation is trimanganese tetraoxide.

[0025] In step S4, the drying and crystallization method is to place the manganese-containing supernatant in at least one of a rotary evaporator, a vacuum drying oven, an oven, and a centrifuge, the drying temperature is 20 to 110° C., and the drying time is 12 to 48 hours; and the manganese salt is obtained by drying and crystallizing.

[0026] According to the method described above, preferably, in step S5, leaching is performed at a solid-liquid ratio of deionized water to vanadium-containing and iron-containing leaching residue of 2 to 20:1 in mL / g, the leaching temperature is 30 to 100° C., and the leaching time is 10 to 100 min; the alkaline solution is at least one of sodium hydroxide solution, ammonia water or hydrogen peroxide solution, and the iron-containing leaching residue is repeatedly rinsed with water having a pH of 7.0 to 14.0 and a temperature of room temperature to 100° C. Further, the leaching can be performed in a water bath or a heating jacket.

[0027] Preferably, in step S6, the vanadium precipitation additive is at least one of ammonium sulfate, ammonium carbonate or ammonium bicarbonate; the vanadium precipitation additive is added in an amount such that the molar ratio of ammonium in the ammonium salt to vanadium in the leaching solution is 1.0 to 3.0; during the vanadium precipitation process, the pH value of the system is maintained at 2 to 3 by adding acid; the acid is at least one of sulfuric acid, hydrochloric acid or nitric acid; the vanadium precipitation temperature is 60 to 100° C., and the vanadium precipitation time is 20 to 180 min.

[0028] Preferably, in step S9, the impurities in the impurity removal are ammonia nitrogen elements.

[0029] (III) Beneficial effects

[0030] The reaction mechanism of the present invention is:

[0031] The method provided by the present invention uses ferromanganese ore as raw material, and uses vanadium industry intermediate products or vanadium products as roasting medium, and utilizes the excellent selective binding and directional reduction ability of vanadium to manganese, so as to achieve the physical phase reconstruction of manganese minerals in ferromanganese ore into acid-soluble vanadates without changing the physical phase of iron minerals. Further, by acid leaching, the leaching solution is adjusted to different pH values, so as to achieve efficient separation of iron and manganese and high recovery rate of vanadium roasting medium, as well as recycling of vanadium roasting medium, so as to effectively avoid the disadvantages of existing separation of iron and manganese in ferromanganese ore.

[0032] The advantages are as follows:

[0033] (1) The present invention limits the molar ratio of n(MnO2) / n(V2O5) to 0.5-3:1, which reflects the synergistic effect of vanadium and manganese. This is because from the low temperature stage (600°C) of roasting, manganese and vanadium combine to form a stable manganese pyrovanadate phase, and the phase does not change when the roasting temperature is further increased. The manganese pyrovanadate phase is easily soluble in an acid solution, which can achieve efficient extraction of manganese and vanadium, separation of manganese and iron, and separation efficiency of iron and manganese in ferromanganese ore. It is much higher than the existing separation method of ferromanganese ore; it avoids the problem of iron and manganese being leached together during leaching of ferromanganese ore, and reduces the subsequent process of removing iron from manganese;

[0034] (2) The inventive method achieves a high recovery rate of vanadium roasting medium by adjusting the leaching solution to different pH values ​​and combining the characteristics of vanadium, and the separated vanadium precipitate can be directly used to prepare a high-purity vanadium pentoxide product;

[0035] (3) The method of the present invention does not release toxic gases during the roasting process;

[0036] (4) The iron-containing tailings of the present invention enrich the iron in the ferromanganese ore into one phase, and its content reaches that of iron concentrate (TFe>60%), which can be directly used in blast furnace smelting of various ferroalloys;

[0037] (5) The addition of vanadium industry intermediates or vanadium products reduces the high roasting reaction temperature during the separation of iron and manganese in traditional ferromanganese ore, further saves costs, and improves the recovery rate of valuable iron and manganese components in ferromanganese ore;

[0038] (6) The intermediate products or vanadium products used as additives in the vanadium industry can be recycled. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0040] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation methods.

[0041] The present invention innovatively uses the intermediate product of the vanadium industry or the vanadium product as an additive to mix and roast with the ferromanganese ore, and utilizes the combination of vanadium and manganese in the low temperature section (600°C) to generate pyrovanadate manganese that is easily soluble in acid. When the roasting temperature is further increased, the physical phase is still pyrovanadate manganese, and the physical phase is relatively stable, and the separation and extraction of iron and manganese are achieved during subsequent leaching. In this process, the manganese element and the vanadium element act synergistically, and neither is indispensable. It is defined that the manganese in the ferromanganese ore is calculated as MnO2, and the vanadium in the intermediate product of the vanadium industry or the vanadium product is calculated as V2O5, and the molar ratio is n(MnO2) / n(V2O5) of 0.5 to 3:1. If n(MnO2) / n(V2O5) is less than 0.5, it will lead to insufficient reaction of the vanadium element with the elements in the ferromanganese ore to generate Fe4Mn3(VO4)6. If n(MnO2) / n(V2O5) is greater than 3, there will be too little vanadium, which is insufficient to completely react with the manganese in the ferromanganese ore to form manganese pyrovanadate. The remaining manganese will combine with iron to form FeMnO3.

[0042] Example 1

[0043] A method for efficiently separating iron and manganese components in iron-manganese ore based on step-by-step leaching, such as Figure 1 As shown, the following steps are included:

[0044] (1) Calcination: grind the iron manganese ore and then screen it. The obtained iron manganese ore has a particle size of 200-250 meshes. Add vanadium pentoxide to mix the mixture, and then mix and roast it. The particle size of vanadium pentoxide is required to be 200-250 meshes so that the vanadium in vanadium pentoxide can further combine with the iron manganese ore. The manganese content in the iron manganese ore is 26.97% in terms of MnO2, and the vanadium content in vanadium pentoxide is 56.02% in terms of V2O5. The iron manganese ore and vanadium pentoxide are mixed at a molar ratio of n(MnO2) / n(V2O5) of 2.5. The mixed mixture is roasted at 850°C for 120 minutes to obtain roasted clinker, and the heating rate is 2° / min. The roasted clinker has a particle size of 250-300 meshes after crushing.

[0045] (2) Primary leaching: The leaching process is carried out in a water bath. Deionized water is added to the leaching container at a liquid-to-solid ratio of 5 mL / g to the roasted clinker. When heated to 70°C, the roasted clinker is added and stirring is started. The pH value of the leaching system is controlled to be around 2.2 by dropping sulfuric acid with a volume fraction of 20%. Both leaching processes are carried out in the same device. In the primary leaching, a sulfuric acid system with a pH value of 2.2 is selected as the leaching medium to achieve the dissolution of manganese vanadate in the roasted clinker. The first stage of the leaching reaction ends after a stable reaction of 60 minutes. No separation operation is performed in this step to ensure the effective separation of manganese and iron;

[0046] (3) Secondary leaching: Continue to drip sulfuric acid solution with a volume fraction of 20% into the system to adjust the pH value of the leaching system to 1.8, so as to achieve the hydrolysis and precipitation of vanadium ions in the vanadium-manganese leaching solution, as shown in reaction equation (1). After 60 minutes of stable reaction, the second stage leaching reaction ends, and then filtration is performed for solid-liquid separation to obtain vanadium-containing iron-containing leaching residue and manganese-containing leaching solution. The leaching residue is repeatedly rinsed with hot water with a pH value of 1.8 and a temperature of 80°C. Among them, the leaching rate is calculated according to formula (2). After leaching, by measuring the content of each element in the leaching solution, it is found that the leaching rate of manganese is 85.97%, while the leaching rate of iron is only 0.00492%, and the leaching rate of vanadium is 5.74%. That is, the leaching solution is a manganese-containing leaching solution, and vanadium and iron are enriched in the leaching residue, achieving efficient separation of iron and manganese.

[0047] 2(VO2) + + H2O = V2O5 ↓ + 2 H + (1)

[0048] Leaching rate (%) = (m L / m0)×100(2)

[0049] Where: m is Mn, Fe or V; m L and m0 is the total mass of m in the leachate and the total mass of m in the roasted sample.

[0050] (4) Recovering manganese: introducing carbon dioxide into the manganese-containing supernatant obtained in step (3) for carbonization at a gas flow rate of 0.1 L / min; during the carbonization process, the pH value of the carbonization system is maintained at 6.8 by adding 5 g / L of sodium hydroxide solution; the carbonization temperature is 40° C.; the carbonization time is 60 min; and then filtering to separate the solid and liquid to obtain a manganese carbonate precipitate and a manganese extraction waste liquid.

[0051] Alternatively, the manganese-containing supernatant obtained in step (3) is electrolyzed to obtain an electrolytic manganese product with a manganese content of >99.7%.

[0052] (5) Separation of vanadium and iron: in a water bath, deionized water is added to a leaching container at a solid-liquid ratio of deionized water to vanadium-containing and iron-containing leaching residue of 5 mL / g, and the vanadium-containing and iron-containing leaching residue is added when heated to 80°C. The pH value of the leaching system is controlled to be 14.0 by adding a hydrogen peroxide solution with a volume fraction of 20%. After leaching at a leaching temperature of 70°C and leaching for 60 minutes, the solid-liquid separation is performed by filtering to obtain a vanadium-containing leaching solution and an iron-containing leaching residue. The leaching residue is repeatedly rinsed with hot water with a pH value of 14.0 and a temperature of 70°C to achieve separation of vanadium and iron.

[0053] (6) Vanadium precipitation: The vanadium precipitation process is carried out in a water bath, and ammonium sulfate is used as a vanadium precipitation additive; the amount of vanadium precipitation additive added is based on the molar ratio of ammonium in the ammonium salt to vanadium in the leachate of 1.5; the basis for calculating the amount of ammonium salt supplementation is shown in equation (3). The vanadium precipitation process is maintained at a pH value of 2 by adding a sulfuric acid solution with a volume fraction of 10%; at a vanadium precipitation temperature of 95°C, after precipitation for 60 minutes, vanadium is precipitated, and the solid and liquid are filtered to separate the polyvanadate ammonium precipitate and vanadium extraction waste liquid. After vanadium precipitation, the vanadium content in the vanadium extraction waste liquid is measured, and the vanadium precipitation rate is obtained to be 99.28%. Among them, the vanadium precipitation rate is calculated according to the following formula: vanadium precipitation rate = (mass of vanadium in the leachate - mass of vanadium in the manganese-containing supernatant) / mass of vanadium in the leachate, and the vanadium circulation rate is more than 90%.

[0054] NH 4+ + H2O = NH3·H2O + H + (3)

[0055] (7) Obtaining vanadium product: The ammonium polyvanadate precipitate is dried at 120° C. for 12 h in advance, and then heated to 550° C. for calcination for 100 min. The obtained vanadium pentoxide has a purity of 99.11% as measured by chemical analysis. The vanadium pentoxide can be output as a vanadium pentoxide product or returned to the calcination system of step (1) to participate in the next round of calcination process.

[0056] (8) Utilization of iron-containing tailings: The iron-containing leaching slag is iron concentrate (TFe>60%), which is directly put into blast furnace smelting. The smelting atmosphere and temperature are controlled to obtain high-quality ferroalloy.

[0057] (9) Impurity removal: After the impurities are removed from the obtained manganese extraction waste liquid and vanadium extraction waste liquid, they are circulated back to the leaching system as the leaching medium in step S2. The impurities to be removed are mainly ammonia nitrogen. The ammonia nitrogen is removed by chemical precipitation, and after the impurities are removed, they are circulated back to the leaching system as the leaching medium for repeated use.

[0058] Example 2

[0059] A method for efficiently separating iron and manganese components in iron-manganese ore based on step-by-step leaching, such as Figure 1 As shown, the following steps are included:

[0060] (1) Calcination: grind the iron manganese ore and then screen it. The obtained iron manganese ore has a particle size of 200-250 meshes. Add ammonium polyvanadate to mix the mixture, and then mix and roast it. The particle size of the ammonium polyvanadate is required to be 200-250 meshes so that the vanadium of the ammonium polyvanadate can further combine with the iron manganese ore. The manganese content in the iron manganese ore used is 26.97% in terms of MnO2, and the vanadium content in the ammonium polyvanadate is 50.50% in terms of V2O5. The iron manganese ore and the ammonium polyvanadate are mixed in a molar ratio of n(MnO2) / n(V2O5) of 2.25. The mixed mixture is evenly roasted at 750°C for 180 minutes to obtain a roasted clinker, and the heating rate is 5° / min. The roasted clinker is crushed to a particle size of 250-300 meshes.

[0061] (2) Primary leaching: The leaching process is carried out in a water bath. Deionized water is added to the leaching container at a liquid-to-solid ratio of 10 mL / g to the roasted clinker. The roasted clinker is added when heated to 80°C. The pH value of the leaching system is controlled to be around 2.5 by adding hydrochloric acid with a volume fraction of 50%. Both leaching stages are carried out in the same device. In the primary leaching, a hydrochloric acid system with a pH value of 2.5 is selected as the leaching medium to achieve the dissolution of manganese vanadate in the roasted clinker. The first stage of the leaching reaction ends after a stable reaction for 60 minutes. No separation operation is performed in this step to ensure the effective separation of manganese and iron;

[0062] (3) Secondary leaching: Continue to drip 50% hydrochloric acid solution into the system to adjust the pH value of the leaching system to 1.7, so as to achieve the hydrolysis and precipitation of vanadium ions in the vanadium-manganese leaching solution. After 60 minutes of stable reaction, the second stage leaching reaction ends. Filter to separate the solid and liquid, obtain vanadium-containing iron-containing leaching residue and manganese-containing leaching solution, and repeatedly rinse the leaching residue with hot water at a pH value of 1.7 and a temperature of 80°C. After leaching, by measuring the contents of iron, manganese and vanadium in the manganese-containing leaching solution, it is found that the manganese leaching rate is 85.96%, while the iron leaching rate is only 0.00685%, and the vanadium leaching rate is only 5.22%, achieving efficient separation of iron and manganese.

[0063] (4) Recovering manganese: adding ammonia water to the manganese-containing leaching solution obtained in step (3) to precipitate manganese ions, maintaining the pH value of the precipitation system at 8.0; the precipitation temperature is 60° C.; the precipitation time is 30 min; then filtering and separating the solid and liquid to obtain manganese tetraoxide precipitate and manganese extraction waste liquid.

[0064] (5) Separation of vanadium and iron: in a water bath, deionized water is added to the leaching container at a solid-liquid ratio of deionized water to vanadium-containing and iron-containing leaching residue of 10 mL / g, and the vanadium-containing and iron-containing leaching residue is added when heated to 60°C. The pH value of the leaching system is controlled to be 12.0 by adding a sodium hydroxide solution with a volume fraction of 20%. After leaching at a leaching temperature of 60°C and 120 minutes, the leaching is filtered for solid-liquid separation to obtain a vanadium-containing leaching solution and an iron-containing leaching residue. The leaching residue is repeatedly rinsed with hot water with a pH value of 12.0 and a temperature of 60°C to achieve separation of vanadium and iron.

[0065] (6) Vanadium precipitation: The vanadium precipitation process is carried out in a water bath, and ammonium sulfate is used as a vanadium precipitation additive; the amount of vanadium precipitation additive added is based on the molar ratio of ammonium in the ammonium salt to vanadium in the leaching solution of 1.3; the vanadium precipitation process is carried out by adding a sulfuric acid solution with a volume fraction of 20% to maintain the pH value of the system at 2; the vanadium precipitation temperature is 100°C, and after precipitation for 40 minutes, vanadium is precipitated, and the solid and liquid are filtered to separate the polyvanadate ammonium precipitate and vanadium extraction waste liquid. After vanadium precipitation, the vanadium content in the vanadium extraction waste liquid is measured, and the vanadium precipitation rate is 98.36%, and its purity is measured by chemical analysis method and is 98.76%. It can be output as a polyvanadate ammonium product, or it can be returned to the roasting system of step (1) to participate in the next round of roasting process, and the vanadium circulation rate is more than 90%.

[0066] (7) Obtaining vanadium product: The ammonium polyvanadate precipitate is dried at 120° C. for 12 h in advance, and then heated to 550° C. and roasted for 120 min. The obtained vanadium pentoxide has a purity of 99.23% as measured by chemical analysis. The vanadium pentoxide can be output as a vanadium pentoxide product or returned to the roasting system of step (1) to participate in the next round of roasting process.

[0067] (8) Utilization of iron-containing tailings: The iron-containing leaching slag is iron concentrate (TFe>60%), which is directly put into blast furnace smelting. The smelting atmosphere and temperature are controlled to obtain high-quality ferroalloy.

[0068] (9) Impurity removal: The impurities that need to be removed from the obtained manganese extraction waste liquid and vanadium extraction waste liquid are mainly ammonia nitrogen, which is removed by conventional chemical precipitation method and circulated back to the leaching system as the leaching medium in step (2) after impurity removal.

[0069] Example 3

[0070] A method for efficiently separating iron and manganese components in iron-manganese ore based on step-by-step leaching, such as Figure 1 As shown, the following steps are included:

[0071] (1) Calcination: The iron manganese ore is ground and sieved to obtain an iron manganese ore with a particle size of 200-250 meshes, and vanadium slag is added for mixing, and then mixed and roasted. The particle size of the vanadium slag is required to be 200-250 meshes so that the vanadium in the vanadium slag can further combine with the iron manganese ore. Among them, the manganese content in the iron manganese ore used is 26.97% in terms of MnO2, and the vanadium content in the vanadium slag is 18.22% in terms of V2O5. The iron manganese ore and vanadium pentoxide are mixed at a molar ratio of n(MnO2) / n(V2O5) of 1.0. The mixed material is evenly roasted at 1000°C for 120 minutes to obtain a roasted clinker, and the heating rate is 10° / min; the roasted clinker is crushed to a particle size of 250-300 meshes.

[0072] (2) Primary leaching: The leaching process is carried out in a heating jacket. Deionized water is added to the leaching container at a liquid-to-solid ratio of 3 mL / g to the roasted clinker. The roasted clinker is added at 90°C and stirring is started. The pH value of the leaching system is controlled to be around 2.8 by adding 30% nitric acid by volume. For the primary leaching, a nitric acid system with a pH value of 2.8 is selected as the leaching medium to achieve the dissolution of manganese vanadate in the roasted clinker. The first stage of the leaching reaction ends after a stable reaction for 60 minutes. No separation operation is performed in this step to ensure the effective separation of manganese and iron;

[0073] (3) Secondary leaching: Continue to add 30% nitric acid solution to the system to adjust the pH value of the leaching system to 1.7, so as to achieve the hydrolysis and precipitation of vanadium ions in the vanadium-manganese leaching solution. After 60 minutes of stable reaction, the second stage leaching reaction is completed. Filter to separate the solid and liquid, obtain vanadium-containing iron-containing leaching slag and manganese-containing leaching solution, and repeatedly rinse the leaching slag with hot water at a pH of 1.7 and a temperature of 90°C. After leaching, by measuring the contents of iron, manganese and vanadium in the manganese-containing leaching solution, it is found that the manganese leaching rate is 170.68%, while the iron leaching rate is only 0.00412%, and the vanadium leaching rate is only 6.54%, achieving efficient separation of iron and manganese. In addition, 7.2% of the manganese in the original vanadium slag is transferred into the manganese-containing vanadium leaching solution after composite roasting and acid leaching. This part of manganese also combines with vanadium in the vanadium slag to form manganese pyrovanadate, and enters the solution through leaching, thereby realizing the recovery and utilization of part of the manganese in the vanadium slag.

[0074] (4) Recovering manganese: adding 20% ​​sodium hydroxide solution to the manganese-containing leaching solution obtained in step (3) to precipitate manganese ions, maintaining the pH value of the precipitation system at about 7.0; the precipitation temperature is 40° C.; the precipitation time is 120 min; filtering and separating the solid and liquid to obtain manganese carbonate precipitate and vanadium extraction waste liquid.

[0075] Utilization of manganese salt: The manganese carbonate precipitate is oxidatively roasted at 400°C for 12 hours, during which oxygen is introduced at a flow rate of 1 L / min to obtain a crude manganese dioxide product, which is then placed in a 15% by volume sulfuric acid solution and a sodium chlorate solution to react for 120 minutes to obtain refined manganese dioxide with a manganese dioxide content of 91.98%. This product can be used as an industrial oxidant and catalyst.

[0076] (5) Separation of vanadium and iron: The process is carried out in a water bath, deionized water is added to a leaching container at a solid-liquid ratio of deionized water to vanadium-containing and iron-containing leaching residue of 3 mL / g, and the vanadium-containing and iron-containing leaching residue is added when heated to 90°C. The pH value of the leaching system is controlled to be 13.0 by adding an ammonia solution with a volume fraction of 50%. After leaching for 60 minutes at a leaching temperature of 70°C, the solid-liquid separation is performed by filtering to obtain a vanadium-containing leaching solution and an iron-containing leaching residue. The leaching residue is repeatedly rinsed with hot water at a pH value of 13.0 and a temperature of 90°C to achieve separation of vanadium and iron.

[0077] (6) Vanadium precipitation: The vanadium precipitation process is carried out in a water bath, and ammonium sulfate is used as a vanadium precipitation additive; the amount of vanadium precipitation additive added is based on the molar ratio of ammonium in the ammonium salt to vanadium in the leaching solution of 2.0; the vanadium precipitation process is carried out by adding a sulfuric acid solution with a volume fraction of 50% to maintain the system pH value at 2.2; at a vanadium precipitation temperature of 90°C, after precipitation for 90 minutes, vanadium is precipitated, and the solid and liquid are separated by filtration to obtain ammonium polyvanadate precipitate and vanadium extraction waste liquid. After vanadium precipitation, the vanadium content in the vanadium extraction waste liquid is determined to obtain a vanadium precipitation rate of 97.35%, and its purity is measured by chemical analysis to be 97.54%. It can be output as an ammonium polyvanadate product, or it can be returned to the roasting system of step (1) to participate in the next round of roasting process.

[0078] (7) Obtaining vanadium product: The ammonium polyvanadate precipitate is dried at 120° C. for 12 h in advance, and then heated to 550° C. for calcination for 150 min. The obtained vanadium pentoxide has a purity of 99.47% as measured by chemical analysis. The vanadium pentoxide can be output as a vanadium pentoxide product or returned to the calcination system of step (1) to participate in the next round of calcination process.

[0079] (8) Utilization of iron-containing tailings: The iron-containing leaching slag is iron concentrate (TFe>60%), which is directly put into blast furnace smelting. The smelting atmosphere and temperature are controlled to obtain high-quality ferroalloy.

[0080] (9) Impurity removal: The impurities that need to be removed from the obtained manganese extraction waste liquid and vanadium extraction waste liquid are mainly ammonia nitrogen, which is removed by chemical precipitation and circulated back to the leaching system as the leaching medium in step (2) after impurity removal.

[0081] Comparative Example 1

[0082] When a conventional sulfuric acid roasting-water leaching method is used to separate iron and manganese from a low-grade iron-manganese ore of manganese oxide (TFe: 30.35%, Mn: 14.30%), it is necessary to introduce not only SO2 but also a large amount of N2 during the roasting process, resulting in a large amount of gas waste; during leaching, it is inevitable that iron and manganese will be leached together, which brings a lot of difficulties to the subsequent removal of iron from manganese.

[0083] Comparative Example 2

[0084] Endophytic fungi are used to bioleach ferromanganese ore (Fe2O3: 67.90%, MnO2: 8.79%). This method requires a 20-day experiment to separate iron and manganese from the ferromanganese ore, but the manganese leaching rate is only 79%, which is much lower than the manganese leaching rate of the present invention. However, different ferromanganese ores require different types of bacteria, and the entire leaching process is slow, which greatly limits this method.

[0085] Comparative Example 3

[0086] 7wt% Na2S2O3 is added as a reducing agent to high-iron manganese oxide ore (TFe: 21.28%, Mn: 39.05%), and a reduction roasting magnetic separation method is used to separate iron and manganese from the iron manganese ore. This method not only requires a high temperature of 1100°C, which has the characteristics of high energy consumption, but also requires a vertical furnace to react, which has a complex process and high production and maintenance costs; the recovery rate of manganese is only 85.96%, which is much lower than the manganese recovery rate of the present invention.

[0087] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any person skilled in the art can use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A method for efficiently separating iron and manganese components in iron-manganese ore based on step-by-step leaching, characterized in that: It includes the following steps: S1. Roasting: Mixing the ferromanganese ore with the intermediate product of the vanadium industry or the vanadium product to obtain a mixed material, wherein the mixing ratio of the ferromanganese ore and the intermediate product of the vanadium industry or the vanadium product is calculated as n(MnO2) / n(V2O5), and n(MnO2) / n(V2O5) is 0.5 to 3:1; roasting the mixed material at a high temperature to obtain a roasted clinker; S2, primary leaching: leaching the roasted clinker obtained in step S1, and adjusting the pH value of the leaching system to 2-3 using an acid solution; S3, secondary leaching: using sulfuric acid solution to continue to adjust the pH value to below 1.8, filtering after leaching, and obtaining manganese-containing leaching solution and vanadium-containing and iron-containing leaching residue; S4, recovering manganese: precipitating or drying and crystallizing the manganese-containing leaching solution obtained in step S3, filtering, and obtaining a manganese product and a manganese extraction waste liquid; S5, separation of vanadium and iron: leaching the vanadium-containing and iron-containing leaching residue obtained in step S3, using an alkaline solution to control the pH value of the leaching system to 7.0-14.0, filtering after leaching to obtain a vanadium-containing leaching solution and an iron-containing leaching residue.

2. The method according to claim 1, characterized in that Also includes: S6, recovering vanadium: adding a vanadium precipitation additive to the vanadium-containing leaching solution obtained in step S5, and adjusting the pH value to 2-3 for vanadium precipitation, and filtering after vanadium precipitation to obtain a vanadium industry intermediate product or vanadium product and vanadium extraction waste liquid; S7. Utilization of vanadium industry intermediate products or vanadium products: the vanadium industry intermediate products or vanadium products obtained in step S6 are output as products, or the vanadium industry intermediate products or vanadium products are recycled back to the roasting system as additives to participate in the next round of roasting; S8, utilization of iron-containing tailings: the iron-containing leached slag obtained in step S5 is used as a blast furnace feed material, or as a raw material for preparing ferroalloy; S9, waste liquid circulation: after impurities are removed from the manganese extraction waste liquid and the vanadium extraction waste liquid obtained in steps S4 and S6, they are circulated back to the leaching system as the leaching medium in step S2.

3. The method according to claim 1, characterized in that In step S1, the ferromanganese ore is a manganese ore with a Mn / Fe mass ratio of less than 3, and is at least one of an oxide mineral, a hydrogenated mineral, a carbonate mineral, a sulfide mineral, a silicate mineral and a borate mineral; and has a particle size of 200 to 300 meshes.

4. The method according to claim 1, characterized in that In step S1, the vanadium industry intermediate product or vanadium product includes at least one of vanadate, vanadium oxide and vanadium slag.

5. The method according to claim 1, characterized in that In step S1, the high temperature calcination temperature is 700-1000°C, the constant temperature time is 10-300min, and the heating rate is 2-10°C / min.

6. The method according to claim 1, characterized in that In step S2, leaching is performed at a liquid-solid ratio of deionized water to roasted clinker of 2 to 20:1 in mL / g, the leaching temperature is 80 to 100° C., and the leaching time is 60 to 180 min.

7. The method according to claim 1, characterized in that In step S4, the precipitation is carried out by carbonization precipitation or direct precipitation. The carbonization precipitation method is to add at least one of carbon dioxide gas, sodium carbonate solution and ammonium carbonate solution to the manganese-containing supernatant, and to maintain the pH value of the carbonization system at 6 to 8 by adding an alkaline solution during the carbonization process. The carbonization temperature is 20 to 100° C., and the carbonization time is 10 to 120 min. The manganese salt obtained by carbonization precipitation is manganese carbonate. The direct precipitation method is to add an alkaline substance to the manganese-containing supernatant to maintain the pH value of the precipitation system at 7 to 10. The direct precipitation temperature is 20 to 100° C., and the precipitation time is 10 to 120 min. The manganese salt obtained by direct precipitation is trimanganese tetraoxide. The drying and crystallization is to place the manganese-containing supernatant in at least one of a rotary evaporator, a vacuum drying oven, an oven and a centrifuge, the drying temperature is 20 to 110° C., and the drying time is 12 to 48 hours; and the manganese salt is obtained by drying and crystallization.

8. The method according to claim 1, characterized in that In step S5, leaching is performed at a solid-liquid ratio of deionized water to vanadium-containing and iron-containing leaching slag of 2 to 20:1 in mL / g, the leaching temperature is 30 to 100° C., and the leaching time is 10 to 100 min.

9. The method according to claim 2, characterized in that In step S6, the vanadium precipitation additive is an ammonium salt, which is at least one of ammonium sulfate, ammonium carbonate or ammonium bicarbonate; the vanadium precipitation additive is added in an amount such that the molar ratio of ammonium in the ammonium salt to vanadium in the leaching solution is 1.0 to 3.0; during the vanadium precipitation process, the pH value of the system is maintained at 2 to 3 by adding acid; the vanadium precipitation temperature is 60 to 100° C., and the vanadium precipitation time is 20 to 180 minutes.

10. The method according to claim 1, characterized in that In step S9, the impurities in the impurity removal are ammonia nitrogen elements.

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