Low-intensity magnetic separation-reverse flotation process for pyrolusite based on hydrogen-based ore phase conversion

Abstract

The invention relates to the technical field of pyrolusite beneficiation, in particular to a low-intensity magnetic separation-reverse flotation process for pyrolusite based on hydrogen-based ore phase transformation. In the prior art, the pyrolusite wet reduction process is high in acid consumption and difficult in waste liquid treatment, and minerals are easy to oxidize and low in magnetism in the roasting process of the dry reduction process. In order to solve the problems, the method comprises the following steps: firstly, carrying out ore grinding to enable the particle size of most mineral aggregates to be less than 38 microns, then carrying out hydrogen-based mineral phase conversion suspension roasting, controlling the use amount of roasting gas, converting pyrolusite into acid-soluble billimanite with weak magnetism, carrying out crystal lattice conversion on quartz, and converting alpha.SiO2 into beta.SiO2, and gangue minerals are separated out through magnetic separation, then flotation is conducted on magnetic concentrate, manganese concentrate is obtained, and the manganese concentrate is high in grade and can serve as a high-activity raw material for leaching electrolytic manganese.

Description

Technical Field

[0001] The invention relates to the technical field of pyrolusite beneficiation, and in particular to a weak magnetic separation-reverse flotation process of pyrolusite based on hydrogen-based ore phase transformation. Background Art

[0002] Pyrolusite is an important mineral resource, widely used in the fields of steel, chemical industry and battery. However, since pyrolusite usually coexists with gangue minerals such as siliceous aluminum gangue and hematite, its mineral composition is complex and its particle size is fine, resulting in many technical challenges in the process of mineral processing and smelting. Traditional roasting and mineral processing processes have high energy consumption and heavy pollution, which are difficult to meet the requirements of modern green mining development. Traditional reduction processes such as wet reduction and dry reduction also have significant defects. Wet reduction usually consumes a lot of acid and is highly corrosive, accompanied by the generation of a large amount of heavy metal-containing waste liquid, which is difficult to treat and puts serious pressure on the environment; while dry reduction has high energy consumption and harsh operating conditions, and mineral oxidation and magnetic reduction are prone to occur during roasting, which limits the separation efficiency. In addition, the high carbon emissions, metal volatilization losses and waste gas and wastewater emissions during roasting and reduction have aggravated environmental pressure and production costs. It is difficult for existing technologies to achieve both green environmental protection and economic efficiency while improving resource utilization efficiency. In order to meet the above challenges, it is urgent to develop a new process that is efficient, energy-saving and environmentally friendly to achieve efficient and clean utilization of pyrolusite resources and promote the development of manganese ore beneficiation in a green and sustainable direction.

[0003] Patent CN110129589 A relates to a method for preparing manganese sulfate solution by reducing roasting and leaching of pyrolusite, in which manganese dioxide is converted into manganese sulfate solution by low-temperature roasting and acid leaching, which is used to prepare manganese-based materials and is combined with waste electrolyte to reduce costs. The method has simple equipment and low processing cost. However, it requires the consumption of high-concentration sulfuric acid, the equipment is highly corrosive, and the carbon powder used for roasting increases carbon emissions, which has high environmental pressure and energy consumption; Patent CN 102861674 B relates to a method for improving the grade of pyrolusite by pre-treating it with silicate bacteria and then flotation, and proposes to grind the pyrolusite ore and then pre-treat it with silicate bacteria, and then reverse flotation. This patent can achieve the separation of manganese and iron and gangue minerals to a certain extent, but the bacterial leaching treatment cycle is long, the process conditions are harsh, it is difficult to deal with complex pyrolusite ores, and there are shortcomings such as insufficient separation of iron and manganese minerals. Summary of the invention

[0004] In view of the problems existing in the existing manganese ore dressing technology, the present invention provides a weak magnetic separation-reverse flotation process for complex pyrolusite based on hydrogen-based ore phase transformation. The invention mainly includes five steps: ceramic ball stirring mill grinding, hydrogen-based ore phase transformation, protective gas cooling, weak magnetic separation and reverse flotation, so as to achieve the precise ore phase transformation of pyrolusite from MnO2 to MnO and the deep separation from iron-silicon-aluminum gangue minerals.

[0005] The present invention provides a weak magnetic separation-reverse flotation process of pyrolusite based on hydrogen-based ore phase transformation, comprising the following steps:

[0006] Step 1: grinding with ceramic ball stirred mill: the raw pyrolusite ore enters into the ceramic ball stirred mill to obtain a ore material with a particle size of -38μm and a content of 50%-80%. The ore material corresponds to the ceramic ball mill ore slurry, which is dried to obtain the roasting raw material.

[0007] Step 2: Hydrogen-based mineral phase transformation: The roasted raw materials obtained in step 1 are placed in a suspension roasting furnace for hydrogen-based mineral phase transformation suspension roasting. Pyrolusite is transformed into weakly magnetic and acid-soluble schistose, and quartz undergoes lattice transformation from α·SiO2 to β·SiO2, thereby obtaining a mineral phase transformation product.

[0008] Step 3: Cooling with protective gas: introducing protective gas to cool the mineral phase transformation product to obtain a cooled product; the protective gas can prevent the mineral phase transformation product from being reoxidized.

[0009] Step 4: Weak magnetic separation: The cooled product is subjected to weak magnetic separation to obtain magnetic concentrate and magnetic tailings.

[0010] Step 5: Reverse flotation separation: reverse flotation is performed on the magnetic concentrate to obtain manganese concentrate.

[0011] Furthermore, in step 1, the concentration of the ceramic ball mill slurry is 30% to 50%.

[0012] Further, in step 2, the mineral phase transformation equation is as follows: MnO2+H2→MnO+H2O, α·SiO2→β·SiO2;

[0013] Furthermore, in step 2, the suspension roasting temperature is 600°C to 800°C, and the roasting gas flow rate at room temperature and pressure is 1200m / ton of roasting raw material. 3 / h-1600m 3 / h, the roasting gas is a mixed gas of hydrogen and nitrogen, wherein the hydrogen gas concentration is 10% to 30%, the suspension roasting time is 20min to 40min, and the reducing gas is hydrogen.

[0014] Furthermore, in step 3, the cooling environment is a nitrogen or inert gas atmosphere, the cooling time is 5 min-15 min, and the cooling product temperature is ≤70°C.

[0015] Furthermore, in step 4, the weak magnetic separation magnetic field strength is 1400Oe to 3200Oe, and the manganese concentrate and gangue minerals are preliminarily separated.

[0016] Furthermore, in step 5, reverse flotation of the magnetic concentrate means that the magnetic concentrate is made into reverse flotation pulp and then enters the reverse flotation operation, and the reverse flotation operation includes 1 stage of roughing, 1 to 2 stages of concentrating and 2 to 5 stages of scavenging operations; a pH adjuster, a combined collector (ZA) and an inhibitor are added to the reverse flotation pulp to enter the roughing operation; after the roughing operation is completed, a roughing concentrate pulp and a roughing tailings pulp are obtained; the roughing tailings pulp is subjected to a scavenging operation without the addition of a collector, and gangue minerals are separated after the scavenging operation is completed; a pH adjuster and a combined collector ZA are added to the roughing concentrate pulp, and the concentrating operation is entered to make the silicon-aluminum gangue minerals adsorb the collector to achieve reverse flotation, and a manganese concentrate is obtained after the concentrating operation is completed.

[0017] Furthermore, in step 5, the pH adjuster includes sodium hydroxide and hydrochloric acid, the combined collector (ZA) is a mixture of sodium oleate and octadecyltrimethylammonium chloride in a mass ratio of 3:1 to 10:1, and the inhibitor includes sodium hexametaphosphate.

[0018] Further, in step 5, the reverse flotation pulp concentration is 35wt% to 55wt% when entering the roughing operation; the materials added to each ton of reverse flotation pulp are as follows: sodium hydroxide and hydrochloric acid are added to make the reverse flotation pulp pH = 8.8 to 9.2; the combined collector ZA is used in an amount of 100g to 800g, and the inhibitor sodium hexametaphosphate is used in an amount of 100g to 1000g;

[0019] When entering the concentration operation, a pH adjuster is added to the roughing concentrate slurry to adjust the pH to pH = 8.8-9.2, and 20g-200g of combined collector ZA is added per ton of roughing concentrate slurry.

[0020] Furthermore, in step 5, the grade of the obtained manganese concentrate is higher than 50%, and the manganese recovery rate is higher than 85%.

[0021] Compared with the conventional technology, the weak magnetic separation-reverse flotation process of pyrolusite based on hydrogen-based ore phase transformation of the present invention has the following beneficial effects:

[0022] 1. The present invention adopts a ceramic ball stirred mill, which not only effectively avoids the introduction of iron ions in the process of steel ball medium grinding, but also can obtain grinding products with uniform particle size and suitable for flotation, without over-grinding and under-grinding, and fully dissociates manganese oxide and gangue minerals.

[0023] 2. The present invention adopts suspension roasting technology to transform the pyrolusite into a hydrogen-based ore phase. While being green and environmentally friendly, it not only transforms the acid- and alkali-insoluble pyrolusite into the weakly magnetic and acid-soluble quartzite, but also provides a guarantee for the subsequent magnetic separation.

[0024] 3. The present invention adopts protective gas cooling and introduces inert gas to cool the material, which effectively prevents the natural oxidation of the newly formed quartzite in an oxidizing atmosphere, increases the content of divalent manganese in the reduced product, and successfully establishes a cooling and anti-oxidation mechanism.

[0025] 4. The present invention adopts the combined collector ZA to deeply remove the silicon aluminum gangue minerals, and further strengthens the agent's effect on Si through the combined synergy between molecules and the electrostatic adsorption between anions and cations. 2+ The binding capacity of active sites has a better capture effect on gangue minerals, and the obtained manganese concentrate can be used as a raw material for high-activity leaching electrolytic manganese.

[0026] 5. The present invention converts pyrolusite into a highly active manganese concentrate that is easy to leach and electrolyze through hydrogen-based ore phase conversion-weak magnetic separation-reverse flotation technology, which saves the amount of reagents used in the next leaching process, and uses hydrogen reduction to effectively reduce carbon emissions, thereby achieving clean and efficient utilization of pyrolusite resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the weak magnetic separation-reverse flotation process of pyrolusite based on hydrogen-based ore phase transformation of the present invention. DETAILED DESCRIPTION

[0028] The following is a clear and complete description of the technical solutions in the implementation of the present invention in conjunction with the embodiments and the accompanying drawings. It should be noted that the embodiments described in the present invention are only used to further explain and illustrate, rather than to limit the scope of application. Based on the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the protection scope of the present invention.

[0029] The process schematic diagram of the present invention is as follows Figure 1 shown.

[0030] Example 1

[0031] This embodiment uses a certain local pyrolusite as a raw material, the main chemical composition of which is total manganese TMn 25.90%, SiO 2 6.98%, Al 2 O 3 3.82%, and is specifically carried out in the following steps:

[0032] Step 1: Grinding with ceramic ball stirred mill: The pyrolusite ore is first put into the ceramic ball stirred mill to obtain a ore material with a particle size of -38 μm and a content of 72%. The ore material has a slurry concentration of 38%, and is dried to obtain a roasted raw material.

[0033] Step 2 Hydrogen-based mineral phase conversion: The roasted raw materials enter the hydrogen-based mineral phase conversion suspension roasting furnace for suspension roasting. The suspension roasting process controls the temperature at 750°C, and the roasting gas flow rate per ton of roasted raw materials is 1550m 3 / h, the roasting gas is a mixed gas of hydrogen and nitrogen, wherein the hydrogen gas concentration is 15%, the roasting time is 25min, and the reducing gas is hydrogen; after the roasting is completed, the mineral phase conversion product is obtained.

[0034] Step 3: Cooling with protective gas: After roasting, the ore phase conversion product is cooled in a nitrogen atmosphere to prevent the schist ore from being oxidized to tetravalent manganese or trivalent manganese. The cooling time is 7 minutes and the temperature is cooled to 70° C. to obtain a cooling product. The schist ore phase conversion rate of the cooling product is 99%.

[0035] Step 4: Weak magnetic separation: The cooled product is subjected to weak magnetic separation with a magnetic field strength of 2000 Oe to obtain magnetic concentrate and magnetic tailings.

[0036] Step 5: Reverse flotation separation: The magnetic concentrate is made into reverse flotation pulp and enters the reverse flotation operation, which includes 1 roughing, 1 cleaning and 3 scavenging operations. The reverse flotation pulp concentration is 42wt%. The pH adjusters sodium hydroxide and hydrochloric acid are added to the reverse flotation pulp to make the pH = 8.89, combined collectors (ZA dosage 400g / t, sodium oleate and octadecyltrimethylammonium chloride mass ratio of 5:1), and inhibitors (sodium hexametaphosphate 500g / t) to enter the roughing operation; after the roughing operation is completed, the roughing concentrate pulp and the roughing tailings pulp are obtained. The roughing tailings pulp is subjected to scavenging operation without the addition of collectors, and the gangue minerals are separated after the scavenging operation. A pH adjuster was added to the roughing concentrate slurry to adjust the pH to 9, and then 100 g / t of collector ZA was added to enter the concentration operation, so that the silicon-aluminum gangue minerals adsorbed the collector to achieve reverse flotation. After the concentration operation, manganese concentrate was obtained. The grade of manganese concentrate was 52.23%, and the recovery rate was 87.42%.

[0037] Example 2

[0038] This embodiment uses a local pyrolusite as a raw material, the main chemical composition of which is total manganese TMn 33.72%, SiO2 5.37%, Al2O3 6.45%. The specific steps are as follows:

[0039] Step 1: Grinding with a ceramic ball stirred mill: The pyrolusite ore is firstly put into a ceramic ball stirred mill to obtain a ore material with a particle size of -38 μm and a content of 78%. The ore material has a slurry concentration of 42% and is dried to obtain a roasted raw material.

[0040] Step 2 Hydrogen-based mineral phase conversion: The roasted raw materials enter the hydrogen-based mineral phase conversion suspension roasting furnace for suspension roasting. The suspension roasting process controls the temperature at 700°C, and the roasting gas flow rate per ton of roasted raw materials is 1300m 3 / h, the roasting gas is a mixed gas of hydrogen and nitrogen, wherein the hydrogen gas concentration is 20%, the roasting time is 30min, and the reducing gas is hydrogen; after the roasting is completed, the mineral phase conversion product is obtained.

[0041] Step 3: Cooling with protective gas: After roasting, the ore phase conversion product is cooled in a nitrogen atmosphere to prevent the schist ore from being oxidized to tetravalent manganese or trivalent manganese. The cooling time is 15 minutes and the product is cooled to 40° C. to obtain a cooling product. The schist ore phase conversion rate of the cooling product is 98%.

[0042] Step 4: Weak magnetic separation: The cooled product is subjected to weak magnetic separation with a magnetic field strength of 3000 Oe to obtain magnetic concentrate and magnetic tailings.

[0043] Step 5: Reverse flotation separation: The magnetic concentrate is made into reverse flotation pulp and enters the reverse flotation operation, which includes 1 roughing, 1 cleaning and 4 scavenging operations. The reverse flotation pulp concentration is 35wt%, and pH adjusters sodium hydroxide and hydrochloric acid are added to the reverse flotation pulp to make pH=8.88, combined collectors (ZA dosage 600g / t, sodium oleate and octadecyltrimethylammonium chloride mass ratio of 7:1), and inhibitors (sodium hexametaphosphate 400g / t) to enter the roughing operation; after the roughing operation is completed, roughing concentrate pulp and roughing tailings pulp are obtained. The roughing tailings pulp is subjected to scavenging operation without the addition of collectors, and the gangue minerals are separated after the scavenging operation. A pH adjuster was added to the roughing concentrate slurry to adjust the pH to 9, and then 200 g / t of collector ZA was added to enter the concentration operation, so that the silicon-aluminum gangue minerals adsorbed the collector to achieve reverse flotation. After the concentration operation, manganese concentrate was obtained. The grade of manganese concentrate was 54.28%, and the recovery rate was 89.30%.

[0044] Example 3

[0045] This embodiment uses a local pyrolusite as a raw material, the main chemical composition of which is total manganese TMn 25.88%, SiO2 10.82%, Al2O3 4.36%. The specific steps are as follows:

[0046] Step 1: Grinding with ceramic ball stirred mill: The pyrolusite ore is first put into the ceramic ball stirred mill to obtain a ore material with a particle size of -38 μm and a content of 80%. The ore material has a slurry concentration of 35%, and is dried to obtain a roasted raw material.

[0047] Step 2 Hydrogen-based mineral phase conversion: The roasted raw materials enter the hydrogen-based mineral phase conversion suspension roasting furnace for suspension roasting. The suspension roasting process controls the temperature at 800°C, and the roasting gas flow rate per ton of roasted raw materials is 1600m 3 / h, the roasting gas is a mixed gas of hydrogen and nitrogen, wherein the hydrogen gas concentration is 30%, the roasting time is 20min, and the reducing gas is hydrogen; after the roasting is completed, the mineral phase conversion product is obtained.

[0048] Step 3: Cooling with protective gas: After roasting, the ore phase conversion product is cooled in a nitrogen atmosphere to prevent the schist ore from being oxidized to tetravalent manganese or trivalent manganese. The cooling time is 10 minutes and the product is cooled to 60° C. to obtain a cooling product. The schist ore phase conversion rate of the cooling product is 97%.

[0049] Step 4: Weak magnetic separation: The cooled product is subjected to weak magnetic separation with a magnetic field strength of 2500 Oe to obtain magnetic concentrate and magnetic tailings.

[0050] Step 5: Reverse flotation separation: The magnetic concentrate is made into reverse flotation pulp and enters the reverse flotation operation, which includes 1 roughing, 2 cleaning and 2 scavenging operations. The reverse flotation pulp concentration is 45wt%, and pH adjusters sodium hydroxide and hydrochloric acid are added to the reverse flotation pulp to make pH = 9.16, combined collectors (ZA dosage 700g / t, sodium oleate and octadecyltrimethylammonium chloride mass ratio of 9:1), inhibitors (sodium hexametaphosphate 400g / t), and enter the roughing operation; after the roughing operation is completed, roughing concentrate pulp and roughing tailings pulp are obtained. The roughing tailings pulp is subjected to scavenging operation without the addition of collectors, and the gangue minerals are separated after the scavenging operation. A pH adjuster was added to the roughing concentrate slurry to adjust the pH to 9, and 100 g / t of collector ZA was added in the first stage of concentration, and 50 g / t of collector ZA was added in the second stage of concentration. The concentration operation was started to make the silicon-aluminum gangue minerals adsorb the collector to achieve reverse flotation. After the concentration operation, manganese concentrate was obtained. The grade of manganese concentrate was 50.31%, and the recovery rate was 86.93%.

[0051] Example 4

[0052] This embodiment uses a certain local pyrolusite as a raw material, the main chemical composition of which is total manganese TMn 32.15%, SiO2 12.79%, Al2O3 5.56%. The specific steps are as follows:

[0053] Step 1: Grinding with a ceramic ball stirred mill: The pyrolusite ore is first put into a ceramic ball stirred mill to obtain a ore material with a particle size of -38 μm and a content of 68%. The ore material has a slurry concentration of 48%, and is dried to obtain a roasted raw material.

[0054] Step 2 Hydrogen-based mineral phase conversion: The roasted raw materials enter the hydrogen-based mineral phase conversion suspension roasting furnace for suspension roasting. The suspension roasting process controls the temperature at 650°C, and the roasting gas flow rate per ton of roasted raw materials is 1450m 3 / h, the roasting gas is a mixed gas of hydrogen and nitrogen, wherein the hydrogen gas concentration is 15%, the roasting time is 35min, and the reducing gas is hydrogen; after the roasting is completed, the mineral phase conversion product is obtained.

[0055] Step 3: Cooling with protective gas: After roasting, the mineral phase conversion product is cooled in a nitrogen atmosphere to prevent the schist ore from being oxidized to tetravalent manganese or trivalent manganese. The cooling time is 8 minutes and the temperature is cooled to 50° C. to obtain a cooling product. The schist ore phase conversion rate of the cooling product is 98%.

[0056] Step 4: Weak magnetic separation: The cooled product is subjected to weak magnetic separation with a magnetic field strength of 2000 Oe to obtain magnetic concentrate and magnetic tailings.

[0057] Step 5 reverse flotation separation: The magnetic concentrate is made into reverse flotation pulp and enters the reverse flotation operation, which includes 1 roughing, 1 concentrating and 2 scavenging operations. The reverse flotation pulp concentration is 52wt%. The pH adjuster sodium hydroxide and hydrochloric acid are added to the reverse flotation pulp to make the pH = 8.97, the combined collector (ZA dosage 600g / t, sodium oleate and octadecyltrimethylammonium chloride mass ratio is 7:1), and the inhibitor (sodium hexametaphosphate 700g / t) enter the roughing operation; after the roughing operation is completed, the roughing concentrate pulp and the roughing tailings pulp are obtained. The roughing tailings pulp is subjected to scavenging operation without the addition of collectors, and the gangue minerals are separated after the scavenging operation. The pH adjuster is added to the roughing concentrate pulp to adjust the pH to pH = 9, and the collector ZA200g / t is added to the concentrating operation, and the silicon aluminum gangue minerals are adsorbed by the collector to achieve reverse flotation. After the concentrating operation is completed, the manganese concentrate is obtained. The grade of manganese concentrate is 54.11% and the recovery rate is 88.34%.

[0058] Comparative Example 1

[0059] Compared with Example 1, the difference is that step 3 does not use protective gas cooling, only air cooling is used, and the remaining steps are the same as Example 1. In step 3, the conversion rate of manganese ore is only 51%, and the grade and recovery rate of manganese concentrate in step 5 are only 44.32% and 68.34%, respectively. The possible reason is that divalent manganese is oxidized to high-valent manganese during the cooling process, and its magnetic properties and surface properties change, thereby reducing the iron-manganese separation in the magnetic separation process and the adsorption effect of the flotation agent in the flotation process.

[0060] Comparative Example 2

[0061] Compared with Example 2, the difference is that step 4 does not use the new collector used in the present invention, but only uses the conventional flotation collector sodium oleate, and the remaining steps are the same as Example 2. Step 5 The manganese concentrate grade is only 41.21%, and a large amount of silicon-containing gangue minerals enter the concentrate.

Claims

1. A weak magnetic separation-reverse flotation process for pyrolusite based on hydrogen-based ore phase transformation, characterized in that: Includes the following: Step 1: grinding with ceramic ball stirred mill: the raw pyrolusite ore enters into the ceramic ball stirred mill to obtain a ore material with a particle size of -38μm and a content of 50%-80%. The ore slurry corresponding to the ore material is the ceramic ball mill slurry, and the roasting raw material is obtained after drying; Step 2: Hydrogen-based mineral phase transformation: the roasted raw material obtained in step 1 is placed in a suspension roasting furnace, and subjected to hydrogen-based mineral phase transformation suspension roasting, pyrolusite is transformed into weakly magnetic and acid-soluble schistostomite, and quartz undergoes lattice transformation from α·SiO2 to β·SiO2, to obtain a mineral phase transformation product; Step 3: Cooling with protective gas: introducing protective gas to cool the mineral phase transformation product to obtain a cooled product; Step 4: Weak magnetic separation: weak magnetic separation is performed on the cooled product to obtain magnetic concentrate and magnetic tailings; Step 5: Reverse flotation separation: reverse flotation is performed on the magnetic concentrate to obtain manganese concentrate.

2. A weak magnetic separation-reverse flotation process for pyrolusite based on hydrogen-based ore phase transformation according to claim 1, characterized in that: In step 1, the concentration of ceramic ball mill slurry is 30% to 50%.

3. A weak magnetic separation-reverse flotation process for pyrolusite based on hydrogen-based ore phase transformation according to claim 1, characterized in that: In step 2, the suspension roasting temperature is 600°C to 800°C, and the roasting gas flow rate at room temperature and pressure is 1200m per ton of roasting raw material. 3 / h-1600m 3 / h, the roasting gas is a mixed gas of hydrogen and nitrogen, wherein the hydrogen gas concentration is 10% to 30%, the suspension roasting time is 20min to 40min, and the reducing gas is hydrogen.

4. A weak magnetic separation-reverse flotation process for pyrolusite based on hydrogen-based ore phase transformation according to claim 1, characterized in that: In step 3, the cooling environment is nitrogen or inert gas atmosphere, the cooling time is 5 min-15 min, and the cooling product temperature is ≤70°C.

5. A weak magnetic separation-reverse flotation process for pyrolusite based on hydrogen-based ore phase transformation according to claim 1, characterized in that: In step 4, the weak magnetic separation magnetic field strength is 1400Oe to 3200Oe, which preliminarily separates the manganese concentrate and the gangue minerals.

6. A weak magnetic separation-reverse flotation process for pyrolusite based on hydrogen-based ore phase transformation according to claim 1, characterized in that: In step 5, reverse flotation of the magnetic concentrate means that the magnetic concentrate is made into reverse flotation pulp and then enters the reverse flotation operation, and the reverse flotation operation includes 1 stage roughing, 1 to 2 stages cleaning and 2 to 5 stages scavenging operations; A pH adjuster, a combined collector ZA and an inhibitor are added to the reverse flotation pulp, and the pulp is put into a roughing operation. After the roughing operation is completed, a roughing concentrate pulp and a roughing tailings pulp are obtained. The roughing tailings pulp is subjected to a scavenging operation without adding a collector, and gangue minerals are separated after the scavenging operation is completed. A pH adjuster and a combined collector ZA are added to the roughing concentrate pulp, and the pulp is put into a concentrating operation, so that the silicon-aluminum gangue minerals adsorb the collector to realize reverse flotation, and a manganese concentrate is obtained after the concentrating operation is completed.

7. A weak magnetic separation-reverse flotation process for pyrolusite based on hydrogen-based ore phase transformation according to claim 6, characterized in that: In step 5, during the reverse flotation operation, the pH adjuster includes sodium hydroxide and hydrochloric acid, the combined collector ZA is a mixture of sodium oleate and octadecyltrimethylammonium chloride in a mass ratio of 3:1 to 10:1, and the inhibitor includes sodium hexametaphosphate.

8. A weak magnetic separation-reverse flotation process for pyrolusite based on hydrogen-based ore phase transformation according to claim 6, characterized in that: In step 5, the reverse flotation pulp concentration is 35wt% to 55wt% when entering the roughing operation; the corresponding materials added per ton of reverse flotation pulp are as follows: sodium hydroxide and hydrochloric acid are added to make the reverse flotation pulp pH = 8.8 to 9.2; the amount of combined collector ZA is 100g to 800g, and the amount of inhibitor sodium hexametaphosphate is 100g to 1000g.

9. A weak magnetic separation-reverse flotation process for pyrolusite based on hydrogen-based ore phase transformation according to claim 6, characterized in that: In step 5, when entering the concentration operation, a pH adjuster is added to the roughing concentrate slurry to adjust the pH to pH = 8.8-9.2, and 20g-200g of the combined collector ZA is added per ton of the roughing concentrate slurry.

10. A weak magnetic separation-reverse flotation process for pyrolusite based on hydrogen-based ore phase transformation according to claim 6, characterized in that: In step 5, the grade of the obtained manganese concentrate is higher than 50%, and the manganese recovery rate is higher than 85%.

Images