Method for improving manganese leaching rate and manganese leaching process thereof

Abstract

The invention discloses a method for improving the manganese leaching rate and a manganese leaching process, and belongs to the technical field of manganese extraction.The method comprises the steps that after the water content of mineral aggregate is adjusted to be 10% or above, microwave pretreatment is conducted; adding an auxiliary agent polyvinylpyrrolidone into the mineral aggregate subjected to microwave treatment; mixing the mineral aggregate added with polyvinylpyrrolidone with water, carrying out wet grinding, and adding ultrasonic treatment in the wet grinding process to obtain ore pulp; concentrated sulfuric acid, water and the obtained ore pulp are mixed for sulfuric acid leaching treatment; and after the sulfuric acid leaching treatment reaction is completed, solid-liquid separation is carried out, and a leaching solution with the high manganese content is obtained. The method can improve the manganese leaching rate of the manganese ore.

Description

Technical Field

[0001] The invention relates to the technical field of manganese extraction technology, and in particular to a method for improving manganese leaching rate and a manganese leaching process of pyrolusite and pyrite based on the method. Background Art

[0002] Battery-grade high-purity manganese sulfate is mainly used to prepare precursors for lithium battery positive electrode ternary materials (lithium nickel cobalt manganese oxide), lithium iron manganese phosphate precursors, and sodium ion battery material precursors, and the market demand is very large.

[0003] In the manganese extraction process, compared with the roasting method, the two-ore one-step method cleverly utilizes two mineral resources, pyrolusite and pyrite, to achieve manganese reduction and leaching in the same reaction system, thereby simplifying multiple steps in the traditional manganese extraction process, eliminating the high-temperature roasting process, significantly improving production efficiency and reducing energy consumption. In the two-ore one-step method, pyrolusite (mainly manganese dioxide) is used as an oxidant, while pyrite (mainly ferrous sulfide) is used as a reducing agent. Under suitable reaction conditions, the two minerals react chemically, and the sulfur element in the pyrite is oxidized to sulfate ions, while releasing electrons, which are accepted by manganese dioxide, thereby reducing it to soluble manganese ions. However, during the production process, it was found that due to the influence of reaction conditions, the two-ore one-step method still has the problem of low leaching rate, and further optimization is urgently needed. Summary of the invention

[0004] In view of the above problems, an object of the present invention is to provide a method for improving the manganese leaching rate and a manganese leaching process of pyrolusite and pyrite based on the method, so as to improve the manganese leaching rate.

[0005] like Figure 1 As shown, the present invention provides a method for improving manganese leaching rate, comprising: S1. After adjusting the moisture content of the ore to above 10%, microwave pretreatment is performed; S2, adding polyvinyl pyrrolidone as an additive to the microwave-treated mineral material; S3, mixing the mineral material to which polyvinyl pyrrolidone is added with water and performing wet grinding, and adding ultrasonic treatment during the wet grinding process to obtain a slurry; S4, concentrated sulfuric acid, and water are mixed with the obtained slurry to perform sulfuric acid leaching treatment; S5. After the sulfuric acid leaching treatment reaction is completed, solid-liquid separation is performed to obtain a leaching solution with a high manganese content.

[0006] The present invention provides a manganese leaching process based on pyrolusite and pyrite, comprising the following steps: Step 1: Microwave pretreatment of pyrolusite and pyrite to improve porosity and cracks In one embodiment, pyrolusite and pyrite are respectively passed through a 5-mesh sieve to ensure uniform particle size of the raw materials; pyrolusite and pyrite are mixed in a mass ratio of 1:1, and the moisture content of the mixed ore is increased to more than 10% by sprinkling water to improve the subsequent microwave treatment effect; the humidified mixed ore is treated by a tunnel microwave machine, the microwave power density is set to 300 W / m³, and the treatment time is 2 to 5 minutes; microwave treatment can significantly increase the porosity and cracks of the ore, creating favorable conditions for the subsequent leaching process. The power of the microwave machine used is P, and the volume of the mixed ore treated is V, then the power density is calculated as follows: power density = P / V.

[0007] Step 2: Add polyvinyl pyrrolidone (PVP) additive to the mixed ore In one embodiment, polyvinyl pyrrolidone (PVP) is added to the mixed ore after microwave treatment, and the addition amount is controlled at 0.1% to 1% by mass; the addition of PVP can improve the wettability of the ore surface and enhance the solubility of metal ions. At the same time, PVP enters the pores and cracks of the ore and fully contacts the ore, promoting the dissolution of metal ions. Combined with subsequent wet grinding and ultrasonic treatment, the auxiliary agent effect is stimulated to further improve the manganese leaching rate; in addition, PVP can prevent the dissolved metal ions from re-precipitating, thereby further improving the manganese leaching rate.

[0008] Step 3: Wet grinding combined with ultrasonic treatment In one embodiment, the mixed ore after adding PVP is mixed with water at a solid-liquid ratio of 1:5 to form a liquid feed; the liquid feed is added to the drum of a wet ball mill, the rotation speed of the wet ball mill is set to 19 r / min, and the wet grinding time is set to 20 minutes; an ultrasonic device is arranged on the outer wall of the drum, and ultrasonic waves are input into the drum body for ultrasonic treatment during wet grinding; the ultrasonic power density is set to 500~1000W / m³, the ultrasonic frequency is 20~50 kHz, and the ultrasonic treatment is intermittent, ultrasonic for 1 minute, paused for 1 minute, and so on. After the wet grinding is completed, a uniform ore slurry is obtained.

[0009] Among them, the power of the ultrasonic device used is P, and the volume of the processed liquid is V, then the power density is calculated as follows: power density = P / V.

[0010] Step 4: Sulfuric acid leaching Concentrated sulfuric acid with a mass percentage concentration of 98%, water and ore pulp are added into a combination barrel in a mass ratio of 1:1:1.5; the stirring speed of the combination barrel is set to 150 r / min, heated to 60-70°C, and reacted for 25-35 minutes to obtain a manganese sulfate solution after the reaction; during this process, pyrite reacts with manganese dioxide in the sulfuric acid solution to generate a manganese sulfate solution.

[0011] Step 5: Solid-liquid separation The manganese sulfate solution after the reaction is pumped into a filter for filtration to obtain leaching residue and leaching liquid; the leaching residue mainly contains SiO2, MnO2, Fe(OH)3, etc., and the leaching liquid is the target product.

[0012] The solution of the present invention has the following characteristics: 1. Use microwave treatment to increase the porosity and cracks of pyrolusite and pyrite After microwave treatment, the porosity of the aggregate was improved and the cracks increased.

[0013] 2. Double mineral material after microwave treatment, adding additive polyvinyl pyrrolidone (PVP) Polyvinyl pyrrolidone (PVP) is a water-soluble polymer. PVP is highly soluble in water, which allows it to be evenly dispersed during the leaching process. It can also be adsorbed in the microporous cracks on the surface of manganese slag to improve the penetration effect of manganese slag. The polar nature of PVP enables it to form adsorption with organic molecules, metal ions or undercharged areas on the surface of minerals through electrostatic effects. The carbonyl and nitrogen atoms of PVP can form hydrogen bonds with water molecules and mineral surfaces, thereby enhancing its stability and adsorption capacity in the leaching medium. PVP can form micelles, encapsulate metal ions, increase their bioavailability and solubility, and thus improve the leaching rate of metals. In addition, during the leaching process, the presence of PVP can reduce the re-precipitation of dissolved metal ions, thereby improving the extraction efficiency.

[0014] 3. Wet grinding of double mineral slurry combined with ultrasonic treatment The cavitation effect of ultrasound can generate microjets and shock waves, which produce strong impact and shear force on ore particles, thereby accelerating the crushing and grinding process of the ore; and can destroy the agglomerates and colloidal structures in the ore, making the ore particles more dispersed and uniform; and ultrasound can promote the dispersion of the additive polyvinyl pyrrolidone (PVP) and dissolve metal ions, thereby stimulating the effectiveness of the additive; the combination of wet grinding and ultrasound can effectively increase the surface energy of the ore, promote the conversion of manganese dioxide to non-stoichiometric low-valent manganese oxides, strengthen the dissociation ability of manganese-containing minerals and silicate gangue monomers, accelerate the reaction rate of pyrolusite, and improve the manganese leaching rate.

[0015] Preferably, the pyrolusite and pyrite are sieved through a 5-mesh sieve and mixed in a mass ratio of 1:1. The water content of the two ores is first increased to about 20%, and then the two ores are passed through a tunnel-type microwave treatment device with a microwave power density of 300 W / m³ and a treatment time of 3 minutes.

[0016] Preferably, polyvinyl pyrrolidone (PVP) is added as an auxiliary agent in an amount of 0.1% to 1%.

[0017] Preferably, it also includes wastewater utilization: washing the leaching residue; filtering the washed leaching residue to further remove moisture and fine particles; the washing wastewater and filter press wastewater are rich in minerals and trace elements, and are used as water for wet ball milling of mineral materials to achieve recycling of resources.

[0018] Preferably, during the wet grinding process, the rotation speed of the wet ball mill is set to 19 r / min, and the wet grinding time is set to 20 minutes; the power density of the ultrasonic treatment is 1000 W / m³, and the ultrasonic frequency is 30 kHz.

[0019] Preferably, in the sulfuric acid leaching treatment, the mass ratio of 98% concentrated sulfuric acid, water and slurry is 1:1:1.5, the reaction temperature is 65° C., and the reaction time is 30 minutes.

[0020] The present invention has at least the following beneficial effects: The method and process of the present invention perform microwave pretreatment on the double ore to improve porosity and increase cracks; polyvinyl pyrrolidone (PVP) is added to the double ore as an auxiliary agent for wet grinding and ultrasonic treatment, so that the auxiliary agent is adsorbed in cracks and gaps on the surface of the double ore, which not only improves the penetration effect of manganese slag, but also improves the subsequent leaching effect and extraction efficiency; in the wet grinding process, combined with ultrasonic treatment, the surface energy of the ore is increased, the conversion of manganese dioxide to non-stoichiometric low-valent manganese oxide is promoted, the dissociation ability of manganese-containing minerals is strengthened, the reaction speed of pyrolusite is accelerated, and the auxiliary agent effect is stimulated, thereby achieving the effect of improving the manganese leaching rate.

[0021] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a process flow chart of the method for improving manganese leaching rate. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with embodiments so that those skilled in the art can implement the invention with reference to the description.

[0024] Example 1 This embodiment provides a method for improving the manganese leaching rate and an example of a manganese leaching process based on pyrolusite and pyrite, comprising the following specific steps: Step 1: Microwave treatment to increase the porosity and cracks of the mineral material Pyrolusite and pyrite were sieved through 5 meshes respectively to ensure uniform particle size of raw materials; pyrolusite and pyrite were mixed in a mass ratio of 1:1, and the moisture content of the mixed ore was increased to about 20% by sprinkling water to improve the subsequent microwave treatment effect; the humidified mixed ore was treated by a tunnel microwave machine, and the microwave power density was set to 300 W / m³, and the treatment time was 3 minutes.

[0025] Step 2: Add polyvinyl pyrrolidone (PVP) Polyvinyl pyrrolidone (PVP) is added to the mixed ore after microwave treatment, and the added amount is controlled at 0.1% by mass.

[0026] Step 3: Wet grinding combined with ultrasonic treatment The mixed ore material after adding PVP was mixed with water at a solid-liquid ratio of 1:5 to form a liquid feed; the liquid feed was added into the drum of the wet ball mill, the speed of the wet ball mill was set to 19 r / min, and the wet grinding time was set to 20 minutes; an ultrasonic device was fixed on the outer wall of the drum, and ultrasonic waves were input into the drum for ultrasonic treatment during wet grinding; the ultrasonic power density was set to 1000W / m³, the ultrasonic frequency was selected to be 30kHz, and the ultrasonic treatment was intermittent, with ultrasonic treatment for 1 minute, 1 minute pause, and so on. After the wet grinding was completed, a uniform ore pulp was obtained.

[0027] Step 4: Sulfuric acid leaching Concentrated sulfuric acid with a mass percentage concentration of 98%, water and ore pulp are added into a combination barrel in a mass ratio of 1:1:1.5; the stirring speed of the combination barrel is set to 150 r / min, heated to 65°C, and reacted for 30 minutes; during this process, pyrite reacts with manganese dioxide in the sulfuric acid solution to generate a manganese sulfate solution.

[0028] Step 5: Solid-liquid separation and wastewater utilization The manganese sulfate solution with complete reaction is pumped into a filter for filtration to obtain leaching residue and leaching liquid; the leaching residue mainly contains SiO2, MnO2, Fe(OH)3, etc.

[0029] The pyrolusite (manganese dioxide ore) used in this embodiment is produced in a certain place in Guangxi, and its total manganese content is 17.4%. The manganese content in the leaching solution is tested, and the manganese leaching rate reaches 96.8%.

[0030] Subsequent treatment of leaching residue: cleaning the leaching residue; filtering the cleaned leaching residue to further remove moisture and fine particles; the cleaning wastewater and filter press wastewater are rich in minerals and trace elements, and are used as water for wet ball milling of mineral materials to achieve the recycling of resources.

[0031] Example 2 The difference from Example 1 is that the amount of polyvinyl pyrrolidone (PVP) added is controlled at 0.5%. The details are as follows: This embodiment provides a method for improving the manganese leaching rate and an example of a manganese leaching process based on pyrolusite and pyrite, comprising the following specific steps: Step 1: Microwave treatment to increase the porosity and cracks of the mineral material Pyrolusite and pyrite were sieved through 5 meshes respectively to ensure uniform particle size of raw materials; pyrolusite and pyrite were mixed in a mass ratio of 1:1, and the moisture content of the mixed ore was increased to about 20% by sprinkling water to improve the subsequent microwave treatment effect; the humidified mixed ore was treated by a tunnel microwave machine, and the microwave power density was set to 300 W / m³, and the treatment time was 3 minutes.

[0032] Step 2: Add polyvinyl pyrrolidone (PVP) Polyvinyl pyrrolidone (PVP) is added to the mixed ore after microwave treatment, and the added amount is controlled at 0.5% by mass.

[0033] Step 3: Wet grinding combined with ultrasonic treatment The mixed ore material after adding PVP was mixed with water at a solid-liquid ratio of 1:5 to form a liquid feed; the liquid feed was added into the drum of the wet ball mill, the speed of the wet ball mill was set to 19 r / min, and the wet grinding time was set to 20 minutes; an ultrasonic device was fixed on the outer wall of the drum, and ultrasonic waves were input into the drum for ultrasonic treatment during wet grinding; the ultrasonic power density was set to 1000W / m³, the ultrasonic frequency was selected to be 30kHz, and the ultrasonic treatment was intermittent, with ultrasonic treatment for 1 minute, 1 minute pause, and so on. After the wet grinding was completed, a uniform ore pulp was obtained.

[0034] Step 4: Sulfuric acid leaching Concentrated sulfuric acid with a mass percentage concentration of 98%, water and ore pulp are added into a combination barrel in a mass ratio of 1:1:1.5; the stirring speed of the combination barrel is set to 150 r / min, heated to 65°C, and reacted for 30 minutes; during this process, pyrite reacts with manganese dioxide in the sulfuric acid solution to generate a manganese sulfate solution.

[0035] Step 5: Solid-liquid separation and wastewater utilization The manganese sulfate solution after the reaction is completely pumped into the filter to be filtered to obtain leaching residue and leaching liquid; the leaching residue mainly contains SiO2, MnO2, Fe(OH)3, etc.

[0036] The pyrolusite (manganese dioxide ore) used in this embodiment is produced in a certain place in Guangxi, and its total manganese content is 17.4%. The manganese content in the leaching solution is tested, and the manganese leaching rate reaches 97.2%.

[0037] Subsequent treatment of leaching residue: cleaning the leaching residue; filtering the cleaned leaching residue to further remove moisture and fine particles; the cleaning wastewater and filter press wastewater are rich in minerals and trace elements, and are used as water for wet ball milling of mineral materials to achieve the recycling of resources.

[0038] Example 3 The difference from Example 1 is that the amount of polyvinyl pyrrolidone (PVP) added is controlled at 0.8%. The details are as follows: This embodiment provides a method for improving the manganese leaching rate and an example of a manganese leaching process based on pyrolusite and pyrite, comprising the following specific steps: Step 1: Microwave treatment to increase the porosity and cracks of the mineral material Pyrolusite and pyrite were sieved through 5 meshes respectively to ensure uniform particle size of raw materials; pyrolusite and pyrite were mixed in a mass ratio of 1:1, and the moisture content of the mixed ore was increased to about 20% by sprinkling water to improve the subsequent microwave treatment effect; the humidified mixed ore was treated by a tunnel microwave machine, and the microwave power density was set to 300 W / m³, and the treatment time was 3 minutes.

[0039] Step 2: Add polyvinyl pyrrolidone (PVP) Polyvinyl pyrrolidone (PVP) was added to the mixed ore after microwave treatment, and the added amount was controlled at 0.8% by mass.

[0040] Step 3: Wet grinding combined with ultrasonic treatment The mixed ore material after adding PVP was mixed with water at a solid-liquid ratio of 1:5 to form a liquid feed; the liquid feed was added into the drum of the wet ball mill, the speed of the wet ball mill was set to 19 r / min, and the wet grinding time was set to 20 minutes; an ultrasonic device was fixed on the outer wall of the drum, and ultrasonic waves were input into the drum for ultrasonic treatment during wet grinding; the ultrasonic power density was set to 1000W / m³, the ultrasonic frequency was selected to be 30kHz, and the ultrasonic treatment was intermittent, with ultrasonic treatment for 1 minute, 1 minute pause, and so on. After the wet grinding was completed, a uniform ore pulp was obtained.

[0041] Step 4: Sulfuric acid leaching Concentrated sulfuric acid with a mass percentage concentration of 98%, water and ore pulp are added into a combination barrel in a mass ratio of 1:1:1.5; the stirring speed of the combination barrel is set to 150 r / min, heated to 65°C, and reacted for 30 minutes; during this process, pyrite reacts with manganese dioxide in the sulfuric acid solution to generate a manganese sulfate solution.

[0042] Step 5: Solid-liquid separation and wastewater utilization The manganese sulfate solution after the reaction is completely pumped into the filter to be filtered to obtain leaching residue and leaching liquid; the leaching residue mainly contains SiO2, MnO2, Fe(OH)3, etc.

[0043] The pyrolusite (manganese dioxide ore) used in this embodiment is produced in a certain place in Guangxi, and its total manganese content is 17.4%. The manganese content in the leaching solution is tested, and the manganese leaching rate reaches 97.9%.

[0044] Subsequent treatment of leaching residue: cleaning the leaching residue; filtering the cleaned leaching residue to further remove moisture and fine particles; the cleaning wastewater and filter press wastewater are rich in minerals and trace elements, and are used as water for wet ball milling of mineral materials to achieve the recycling of resources.

[0045] Example 4 The difference from Example 1 is that the amount of polyvinyl pyrrolidone (PVP) added is controlled at 1%. The details are as follows: This embodiment provides a method for improving the manganese leaching rate and an example of a manganese leaching process based on pyrolusite and pyrite, comprising the following specific steps: Step 1: Microwave treatment to increase the porosity and cracks of the mineral material Pyrolusite and pyrite were sieved through 5 meshes respectively to ensure uniform particle size of raw materials; pyrolusite and pyrite were mixed in a mass ratio of 1:1, and the moisture content of the mixed ore was increased to about 20% by sprinkling water to improve the subsequent microwave treatment effect; the humidified mixed ore was treated by a tunnel microwave machine, and the microwave power density was set to 300 W / m³, and the treatment time was 3 minutes.

[0046] Step 2: Add polyvinyl pyrrolidone (PVP) Polyvinyl pyrrolidone (PVP) is added to the mixed mineral material after microwave treatment, and the added amount is controlled at 1% by mass.

[0047] Step 3: Wet grinding combined with ultrasonic treatment The mixed ore material after adding PVP was mixed with water at a solid-liquid ratio of 1:5 to form a liquid feed; the liquid feed was added into the drum of the wet ball mill, the speed of the wet ball mill was set to 19 r / min, and the wet grinding time was set to 20 minutes; an ultrasonic device was fixed on the outer wall of the drum, and ultrasonic waves were input into the drum for ultrasonic treatment during wet grinding; the ultrasonic power density was set to 1000W / m³, the ultrasonic frequency was selected to 30 kHz, and the ultrasonic treatment was intermittent, with ultrasonic treatment for 1 minute, 1 minute pause, and so on. After the wet grinding was completed, a uniform ore pulp was obtained.

[0048] Step 4: Sulfuric acid leaching Concentrated sulfuric acid with a mass percentage concentration of 98%, water and ore pulp are added into a combination barrel in a mass ratio of 1:1:1.5; the stirring speed of the combination barrel is set to 150 r / min, heated to 65°C, and reacted for 30 minutes; during this process, pyrite reacts with manganese dioxide in the sulfuric acid solution to generate a manganese sulfate solution.

[0049] Step 5: Solid-liquid separation and wastewater utilization The manganese sulfate solution after the reaction is completely pumped into the filter to be filtered to obtain leaching residue and leaching liquid; the leaching residue mainly contains SiO2, MnO2, Fe(OH)3, etc.

[0050] The pyrolusite (manganese dioxide ore) used in this embodiment is produced in a certain place in Guangxi, and its total manganese content is 17.4%. The manganese content in the leaching solution is tested, and the manganese leaching rate reaches 98.1%.

[0051] Subsequent treatment of leaching residue: cleaning the leaching residue; filtering the cleaned leaching residue to further remove moisture and fine particles; the cleaning wastewater and filter press wastewater are rich in minerals and trace elements, and are used as water for wet ball milling of mineral materials to achieve the recycling of resources.

[0052] Comparative Example 1 The difference from Example 1 is that no microwave pretreatment, no addition of polyvinyl pyrrolidone (PVP), and no ultrasonic treatment are performed. The details are as follows: A manganese leaching process based on pyrolusite and pyrite comprises the following specific steps: Step 1: Mix the two ores Pass the pyrolusite and pyrite through a 5-mesh sieve to ensure uniform particle size of the raw materials; then mix them in a mass ratio of 1:1; Step 2: Wet grinding The mixed ore and water are mixed at a solid-liquid ratio of 1:5 to form a liquid. The liquid is added into the drum of a wet ball mill. The speed of the wet ball mill is set to 19 r / min and the wet grinding time is set to 20 minutes. After the wet grinding is completed, a uniform slurry is obtained.

[0053] Step 3: Sulfuric acid leaching Concentrated sulfuric acid with a mass percentage concentration of 98%, water and ore pulp are added into a combination barrel in a mass ratio of 1:1:1.5; the stirring speed of the combination barrel is set to 150 r / min, heated to 65°C, and reacted for 30 minutes; during this process, pyrite reacts with manganese dioxide in the sulfuric acid solution to generate a manganese sulfate solution.

[0054] Step 4: Solid-liquid separation The manganese sulfate solution after the reaction is completely pumped into the filter to be filtered to obtain leaching residue and leaching liquid; the leaching residue mainly contains SiO2, MnO2, Fe(OH)3, etc.

[0055] The pyrolusite (manganese dioxide ore) used in this comparative example was produced in a certain place in Guangxi, and its total manganese content was 17.4%. The manganese content in the leaching solution was tested, and the manganese leaching rate reached 88.6%.

[0056] Comparative Example 2 The difference from Example 1 is that polyvinyl pyrrolidone (PVP) is added in the sulfuric acid leaching step instead of before wet grinding. The details are as follows: A manganese leaching process based on pyrolusite and pyrite comprises the following specific steps: Step 1: Mix the two ores Pass the pyrolusite and pyrite through a 5-mesh sieve to ensure uniform particle size of the raw materials; then mix them in a mass ratio of 1:1; Step 2: Wet grinding The mixed ore and water are mixed at a solid-liquid ratio of 1:5 to form a liquid. The liquid is added into the drum of a wet ball mill. The speed of the wet ball mill is set to 19 r / min and the wet grinding time is set to 20 minutes. After the wet grinding is completed, a uniform slurry is obtained.

[0057] Step 3: Sulfuric acid leaching Concentrated sulfuric acid with a mass percentage concentration of 98%, water, ore pulp and polyvinyl pyrrolidone (PVP) are added into a chemical combination barrel, the mass ratio of concentrated sulfuric acid with a mass percentage concentration of 98%, water and ore pulp is 1:1:1.5, and the amount of polyvinyl pyrrolidone (PVP) added is 0.1% by mass percentage of the mixed ore in the ore pulp; the stirring speed of the chemical combination barrel is set to 150 r / min, heated to 65°C, and reacted for 30 minutes; during this process, pyrite reacts with manganese dioxide in sulfuric acid solution to generate manganese sulfate solution.

[0058] Step 5: Solid-liquid separation and wastewater utilization The manganese sulfate solution after the reaction is completely pumped into the filter to be filtered to obtain leaching residue and leaching liquid; the leaching residue mainly contains SiO2, MnO2, Fe(OH)3, etc.

[0059] The pyrolusite (manganese dioxide ore) used in this comparative example was produced in a certain place in Guangxi, and its total manganese content was 17.4%. The manganese content in the leaching solution was tested, and the manganese leaching rate reached 91.4%.

[0060] It can be seen that the present invention adopts microwave pretreatment, addition of polyvinyl pyrrolidone (PVP) before wet grinding, and ultrasonic combined with wet grinding leaching process, which effectively improves the leaching rate, which can be as high as 98.1% and as low as 96.8%, which is significantly improved compared with the traditional scheme of comparative example 1 (leaching rate 88.6%) and the sulfuric acid leaching and PVP addition scheme of comparative example 2 (leaching rate 91.4%).

[0061] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. They can be applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized.

Claims

1. A method for improving manganese leaching rate, characterized in that: include: S1. After adjusting the moisture content of the ore to above 10%, microwave pretreatment is performed; S2, adding polyvinyl pyrrolidone as an additive to the microwave-treated mineral material; S3, mixing the mineral material to which polyvinyl pyrrolidone is added with water and performing wet grinding, and adding ultrasonic treatment during the wet grinding process to obtain a slurry; S4, concentrated sulfuric acid, and water are mixed with the obtained slurry to perform sulfuric acid leaching treatment; S5. After the sulfuric acid leaching treatment reaction is completed, solid-liquid separation is performed to obtain a leaching solution with a high manganese content.

2. A manganese leaching process based on pyrolusite and pyrite, characterized in that: The method according to claim 1 is used to treat the dual ore materials of pyrolusite and pyrite to obtain a leaching solution.

3. The manganese leaching process based on pyrolusite and pyrite as claimed in claim 2, characterized in that: The power density of microwave pretreatment was 300 W / m³ and the treatment time was 2-5 min.

4. The manganese leaching process based on pyrolusite and pyrite as claimed in claim 3, characterized in that: The added amount of the polyvinyl pyrrolidone is controlled at 0.1%-1%.

5. The manganese leaching process based on pyrolusite and pyrite as claimed in claim 4, characterized in that: During the wet grinding process, the speed of the wet ball mill was set at 19 r / min, and the wet grinding time was set at 15-25 minutes; the power density of the ultrasonic treatment was 1000 W / m³, and the ultrasonic frequency was 20 kHz - 50 kHz.

6. The manganese leaching process based on pyrolusite and pyrite as claimed in claim 4, characterized in that: In the sulfuric acid leaching treatment, the mass ratio of 98% concentrated sulfuric acid, water and slurry is 1:1:1.5, the reaction temperature is 60°C-70°C, and the reaction time is 25-35 minutes.

7. The manganese leaching process based on pyrolusite and pyrite as claimed in claim 2, characterized in that: Specifically include: Step 1, sieving pyrolusite and pyrite through a 5-mesh sieve respectively; mixing pyrolusite and pyrite in a mass ratio of 1:1, and adjusting the moisture content of the mixed ore to 10-20%; treating the humidified mixed ore by a tunnel microwave machine, setting the microwave power density to 300 W / m³, and treating for 3 minutes; Step 2, adding polyvinyl pyrrolidone as an additive to the mixed ore after microwave treatment, with the addition amount being 0.1%-1%; Step 3, the mixed ore material after adding polyvinyl pyrrolidone is mixed with water at a solid-liquid ratio of 1:5, and added into a wet ball mill, the speed of the wet ball mill is set to 19 r / min, the wet grinding time is set to 20 minutes, and after the wet grinding is completed, a slurry is obtained; during the wet grinding process, ultrasonic treatment is performed at the same time, the ultrasonic power density is 1000 W / m³, the ultrasonic frequency is 30 kHz, the ultrasonic treatment is intermittent treatment, ultrasonic treatment for 1 minute, pause for 1 minute, and so on; Step 4, adding concentrated sulfuric acid with a mass percentage concentration of 98%, water and ore pulp in a mass ratio of 1:1:1.5 into a chemical combination barrel; setting the stirring speed of the chemical combination barrel to 150 r / min, heating to 60-70° C., reacting for 30 minutes, and obtaining a manganese sulfate solution after the reaction; Step 5: pump the manganese sulfate solution after the reaction into a filter for filtering to obtain leaching residue and target product leaching solution.

8. The manganese leaching process based on pyrolusite and pyrite according to claim 7, characterized in that: The step also includes step 6, a wastewater utilization step: washing the leached residue, and filtering the washed leached residue to further remove moisture and particles; the washing wastewater and the filter press wastewater are used as water for wet grinding of mineral materials.

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