Method for preparing low-impurity manganese sulfate solution by using manganese oxide ore as raw material

Abstract

The invention relates to the technical field of hydrometallurgy, and discloses a method for preparing a low-impurity manganese sulfate solution by taking manganese oxide ore as a raw material, which comprises the following steps of: ball-milling the manganese oxide ore into powder, adding the manganese oxide ore powder into a dilute sulfuric acid aqueous solution, soaking and pickling at normal temperature, carrying out solid-liquid separation, and mixing the pickled manganese oxide ore powder with hydrated slurry to obtain a mixture; and adding the slurry into a reaction kettle, stirring, heating the slurry to 60-80 DEG C, introducing copper smelting tail gas, reacting and leaching, adding a proper amount of reduced manganese powder (MnO) and BaS into the leached slurry, and filtering to remove slag, thereby obtaining the low-impurity manganese sulfate solution. After the manganese oxide ore is subjected to ball milling, acid pickling and slurrying, the copper smelting sulfur dioxide tail gas is introduced for reduction leaching, the manganese sulfate solution containing extremely low impurity element ions such as K <->, Na < + >, Ca < 2 + > and Mg < 2 + > is prepared, the total manganese leaching rate of the manganese oxide ore is high, the process flow is short, and the production efficiency is high.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrometallurgy, and in particular relates to a method for preparing a low-impurity manganese sulfate solution by taking manganese oxide ore as a raw material. Background Art

[0002] Manganese oxide ore is an important raw material for producing battery-grade manganese sulfate and high-purity manganese oxide. There are two main types of leaching of manganese oxide ore in the sulfate system. One is the traditional process of roasting and reducing manganese oxide ore, which uses coal as a reducing agent to roast and reduce the MnO in the manganese oxide ore. 2 Converted into MnO, and then leached with sulfuric acid. However, this method has problems such as high energy consumption, poor operating conditions, and serious environmental pollution. Another leaching method is the two-ore acid method, which is to mix manganese oxide ore and pyrite with sulfuric acid in a certain ratio to form a slurry, and at a certain temperature, the high-valent manganese in the manganese oxide ore is reduced to form manganese sulfate. The leachate is then subjected to the steps of iron removal, weight removal, calcium removal, magnesium removal, defluorination, filtration, crystallization, and drying to produce battery-grade manganese sulfate. This method eliminates the high-temperature reduction roasting process, reduces labor intensity, improves labor conditions, and simplifies the production process. It is one of the better methods for producing battery-grade manganese sulfate.

[0003] However, the above two methods for leaching manganese oxide ore inevitably cause impurity element ions such as calcium, magnesium, potassium, and sodium to enter the manganese sulfate leachate during the leaching process. Taking calcium and magnesium ions as an example, the Ca ion concentration in the leachate is about 600 mg / L, and the Mg ion concentration is about 400-800 mg / L. In order to make the impurity element content in the product meet the standard, the leaching solution must be subjected to iron removal, weight removal, calcium removal, magnesium removal, defluorination, turbidity adjustment and other impurity removal operations to meet the requirements of solution crystallization or oxidation precipitation of manganese. Therefore, the front-end solution purification process of general battery-grade manganese products is long, the operation is extremely cumbersome, and the production cost remains high. In the current increasingly fierce market competition environment, most manufacturers are unable to continue due to production and operation difficulties, and some manufacturers have been in a state of suspension for a long time.

[0004] At present, in order to reduce the cost of acid leaching of manganese oxide ore, production enterprises have gradually carried out the 2 ) Research and application of absorption and reduction of manganese oxide ore. This process first uses ball milling to prepare fine-grained manganese oxide ore powder, and removes the leachable impurity elements contained in the manganese oxide ore by washing with dilute sulfuric acid, removing impurity elements such as calcium, magnesium, potassium, and sodium that are difficult to separate by hydrometallurgy from the source of raw materials. Secondly, public reports show that smelting tail gas (SO 2 ) The equipment used for absorbing and reducing manganese oxide ore is absorption tower or conventional reactor, SO 2 The absorption and utilization efficiency is low, and multi-stage series absorption is required. The equipment is huge, and there are technical disadvantages such as long leaching and purification process, complicated operation and high cost. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing a low-impurity manganese sulfate solution using manganese oxide ore as a raw material, in view of the above problems, which are the disadvantages of the above manganese oxide ore leaching and purification process, such as long process flow, complicated operation and high cost.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows: a method for preparing a low-impurity manganese sulfate solution using manganese oxide ore as a raw material, comprising the following steps:

[0007] S1: ball-milling the manganese oxide ore into powder;

[0008] S2: taking an appropriate amount of the manganese oxide ore powder prepared in step S1, adding it to a dilute sulfuric acid aqueous solution, soaking and acid washing at room temperature, and separating the solid from the liquid;

[0009] S3: mixing the pickled manganese oxide ore powder with water to form a slurry;

[0010] S4: adding the slurry from step S3 into the gas flow tube reactor and stirring, and heating the slurry temperature to 60-80° C.;

[0011] S5: The slurry in step S4 is introduced into the copper smelting tail gas for reaction and leaching, and the volume content of sulfur dioxide in the copper smelting tail gas is 20% to 50%;

[0012] S6: Add appropriate amount of reduced manganese powder (MnO) and BaS to the slurry in step S5, quickly adjust the pH of the slurry solution to 4.5-5.5, filter and remove slag to remove Fe 3+ 、Al 3+ 、SI 4+ and heavy metals and other impurity elements to produce low K - 、Na + , Ca 2 + Mg 2+ Manganese sulfate solution with extremely low impurity element ions.

[0013] Preferably, in step S1, the manganese oxide ore is ball-milled to a size of 200-600 mesh.

[0014] Preferably, in step S2, the concentration of the dilute sulfuric acid aqueous solution is 20 to 100 g / L, and the room temperature pickling time is 1 to 4 hours.

[0015] Preferably, in step S3, the solid-liquid weight ratio of the manganese oxide ore powder to water is 1:4 to 1:2.

[0016] Preferably, in step S4, the stirring rate is 400-800 rpm.

[0017] Preferably, in step S5, the reaction pressure is 1-5 kPa, and the reaction time is 3-6 h.

[0018] Preferably, in step S5, the volume content of sulfur dioxide in the copper smelting tail gas is 40%.

[0019] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0020] The present invention uses ball milling to prepare fine-grained manganese oxide ore powder, removes leachable impurity elements contained in the manganese oxide ore by washing with dilute sulfuric acid, removes impurity elements such as calcium, magnesium, potassium, and sodium that are difficult to separate by hydrometallurgy from the source of raw materials, and broadens the SO 2 Applicable types of tail gas reduction leaching of manganese oxide ore; after pickling and pulping, copper smelting SO 2 The tail gas is used to reduce and leach manganese oxide ore with low acid. Since the ore powder has a fine particle size and the wet material of the ore powder after acid washing contains a certain amount of sulfuric acid, the divalent manganese in the manganese oxide ore continues to be leached during the reduction leaching process. The ore powder has a high degree of activation, which is beneficial to SO 2 The low-acid reduction leaching reaction is carried out, the impurity element ion content in the leaching solution is small, and the total manganese leaching rate of manganese oxide ore is high, and the leaching rate can reach more than 97%;

[0021] Adding appropriate amount of reduced manganese powder (MnO) and BaS impurity remover, quickly adjusting the pH of the slurry solution to 5.5, can quickly and effectively remove the impurity element ions in the manganese sulfate solution. After filtration, the manganese sulfate solution contains Fe 3+ 、Al 3+ 、SI 4+ , K - 、Na + , Ca 2+ Mg 2+ And heavy metal and other impurity element ions, the content is extremely low.

[0022] The leaching reduction reaction equipment of this process adopts a gas flow tube reactor. 2 During the absorption-reduction leaching process, the stirring liquid surface will generate turbulence and eddy currents, forming negative pressure on the liquid surface, reducing the SO 2 The escape of SO 2 The separation phenomenon between the two phases of the slurry improves the transfer and mixing of substances in the reaction system, thereby increasing SO 2 The reduction leaching reaction rate and reaction effect of manganese oxide ore simplifies the equipment scale.

[0023] Compared with the existing process, this leaching process is suitable for any type of manganese oxide ore with high SO 2Reduction leaching, and the total Mn leaching rate of manganese oxide ore is higher; the consumption of leaching sulfuric acid is fundamentally reduced, and the manganese sulfate solution after impurity removal does not need to remove calcium, magnesium and defluorination processes to be used in the production of manganese products. The process flow is short, the production efficiency is high, it has high applicability to manganese oxide ore categories, the production cost is extremely low, and it has great production application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a production process flow chart of the present invention; DETAILED DESCRIPTION

[0025] The specific implementation modes of the present invention are further described below in conjunction with examples.

[0026] Example 1

[0027] A method for preparing a low-impurity manganese sulfate solution using manganese oxide ore as a raw material comprises the following steps:

[0028] S1: ball-mill 1# manganese oxide ore (Mn: 43.96%-dry basis, Fe: 2.20%, moisture: 43.29%) to 200 mesh;

[0029] S2: Take an appropriate amount of manganese oxide ore powder, add it to a dilute sulfuric acid aqueous solution with a concentration of 50g / L, soak and pickle at room temperature for 4h, and separate the solid and liquid;

[0030] S3: mixing the pickled manganese oxide ore powder with water in a solid-liquid weight ratio of 1:2 to form a slurry;

[0031] S4: Add the slurry from step 3 into a 30L draft tube reactor and stir at a stirring rate of 600 rpm, and heat the slurry temperature to 75°C;

[0032] S5: In step 4, the slurry is introduced into the copper smelting tail gas for reaction and leaching. The volume content of sulfur dioxide in the copper smelting tail gas is 40%, the reaction pressure is 3.0 kPa, and the reaction time is 4 hours. The reaction in this step is an exothermic reaction, and the temperature during the reaction rises to 80-95°C;

[0033] S6: Add appropriate amount of reduced manganese powder (MnO) and BaS to the slurry in step 5, quickly adjust the pH of the slurry solution to 5.5, filter and remove the slag to remove Fe 3+ 、Al 3+ 、Si 4+ and heavy metals and other impurity elements to obtain K - 、Na + , Ca 2+ Mg 2+ Manganese sulfate solution with extremely low impurity element ions.

[0034] The total manganese leaching rate of 1# manganese oxide ore is: 97.56%, and the indicators of low-impurity manganese sulfate solution are shown in the following table:

[0035] Table 1 Manganese sulfate solution indicators

[0036]

[0037] Example 2

[0038] A method for preparing a low-impurity manganese sulfate solution using manganese oxide ore as a raw material comprises the following steps:

[0039] S1: ball-mill 2# manganese oxide ore (Mn: 37.96%-dry basis, Fe: 3.42%, moisture: 8.55%) to 200 mesh;

[0040] S2: Take an appropriate amount of manganese oxide ore powder, add it to a dilute sulfuric acid aqueous solution with a concentration of 50g / L, soak and pickle at room temperature for 4h, and separate the solid and liquid;

[0041] S3: slurrying the pickled manganese oxide ore powder with water in a solid-liquid weight ratio of 1:3;

[0042] S4: Add the slurry from step 3 into a 30L draft tube reactor and stir at a stirring rate of 600 rpm, and heat the slurry temperature to 75°C;

[0043] S5: In step 4, the slurry is introduced into the copper smelting tail gas for reaction and leaching. The volume content of sulfur dioxide in the copper smelting tail gas is 40%. The reaction pressure is 3.0 kPa and the reaction time is 4 hours. The reaction in this step is an exothermic reaction and the reaction temperature rises to 80-95°C.

[0044] S6: Add appropriate amount of reduced manganese powder (MnO) and BaS to the slurry in step 5, quickly adjust the pH of the slurry solution to 5.5, filter and remove the slag to remove Fe 3+ 、Al 3+ 、Si 4+ and heavy metals and other impurity elements to obtain K - 、Na + , Ca 2+ Mg 2+ Manganese sulfate solution with extremely low impurity element ions;

[0045] The total manganese leaching rate of 2# manganese oxide ore is: 98.47%, and the indicators of low-impurity manganese sulfate solution are shown in the following table:

[0046]

[0047] Example 3

[0048] A method for preparing a low-impurity manganese sulfate solution using manganese oxide ore as a raw material comprises the following steps:

[0049] S1: ball-mill 3# manganese oxide ore (Mn: 39.85%-dry basis, Fe: 6.95%, moisture: 2.17%) to 200 mesh;

[0050] S2: Take an appropriate amount of manganese oxide ore powder, add it to a dilute sulfuric acid aqueous solution with a concentration of 50g / L, soak and pickle at room temperature for 4h, and separate the solid and liquid;

[0051] S3: slurrying the pickled manganese oxide ore powder with water in a solid-liquid weight ratio of 1:3;

[0052] S4: Add the slurry from step 3 into a 30L draft tube reactor and stir at a stirring rate of 600 rpm; heat the slurry temperature to 75°C;

[0053] S5: In step 4, the slurry is introduced into the copper smelting tail gas for reaction and leaching. The volume content of sulfur dioxide in the copper smelting tail gas is 40%. The reaction pressure is 3.0 kPa and the reaction time is 4 hours. The reaction in this step is an exothermic reaction and the reaction temperature rises to 80-95°C.

[0054] S6: Add appropriate amount of reduced manganese powder (MnO) and BaS to the slurry in step 5, quickly adjust the pH of the slurry solution to 5.5, filter and remove the slag to remove Fe 3+ 、Al 3+ 、Si 4+ and heavy metals and other impurity elements to obtain K - 、Na + , Ca 2+ Mg 2+ Manganese sulfate solution with extremely low impurity element ions;

[0055] The total manganese leaching rate of 3# manganese oxide ore is: 99.32%, and the indicators of low-impurity manganese sulfate solution are shown in the following table:

[0056]

[0057] The above description is a detailed description of the preferred embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modified modifications accomplished under the guidance of the present invention should belong to the patents covered by the present invention.

Claims

1. A method for preparing a low-impurity manganese sulfate solution using manganese oxide ore as a raw material, characterized in that: The following steps are involved: S1: ball-milling the manganese oxide ore into powder; S2: taking an appropriate amount of the manganese oxide ore powder prepared in step S1, adding it to a dilute sulfuric acid aqueous solution, soaking and acid washing at room temperature, and separating the solid from the liquid; S3: mixing the pickled manganese oxide ore powder with water slurry; S4: adding the slurry from step S3 into the gas flow tube reactor and stirring, and heating the slurry temperature to 60-80° C.; S5: The slurry in step S4 is introduced into the copper smelting tail gas for reaction and leaching, and the volume content of sulfur dioxide in the copper smelting tail gas is 20% to 50%; S6: Add appropriate amount of reduced manganese powder (MnO) and BaS to the slurry in step S5, quickly adjust the pH of the slurry solution to 4.5-5.5, filter and remove slag to remove Fe 3+ 、Al 3+ 、SI 4+ and heavy metals and other impurity elements to produce low K - 、Na + , Ca 2+ Mg 2+ Manganese sulfate solution with extremely low impurity element ions.

2. The method for preparing a low-impurity manganese sulfate solution using manganese oxide ore as a raw material according to claim 1, characterized in that: In step S1, the manganese oxide ore is ball-milled to 200-600 meshes.

3. The method for preparing a low-impurity manganese sulfate solution using manganese oxide ore as a raw material according to claim 1, characterized in that: In step S2, the concentration of the dilute sulfuric acid aqueous solution is 20 to 100 g / L, and the room temperature pickling time is 1 to 4 hours.

4. The method for preparing a low-impurity manganese sulfate solution using manganese oxide ore as a raw material according to claim 1, characterized in that: In step S3, the solid-liquid weight ratio of the manganese oxide ore powder to water is 1:4 to 1:

2.

5. The method for preparing a low-impurity manganese sulfate solution using manganese oxide ore as a raw material according to claim 1, characterized in that: In step S4, the stirring rate is 400-800 rpm.

6. The method for preparing a low-impurity manganese sulfate solution using manganese oxide ore as a raw material according to claim 1, characterized in that: In step S5, the reaction pressure is 1-5 kPa, and the reaction time is 3-6 h.

7. The method for preparing a low-impurity manganese sulfate solution using manganese oxide ore as a raw material according to claim 1, characterized in that: In step S5, the volume content of sulfur dioxide in the copper smelting tail gas is 40%.

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