Low-cost impurity removal method for by-product manganese salt

Abstract

The invention relates to the technical field of manganese sulfate for manganous-manganic oxide materials, in particular to a low-cost impurity removal method for a by-product manganese salt, which comprises the following steps: by taking the by-product manganese salt as a manganese source, sequentially adding a coagulation agent, an impurity removal agent and an extraction agent to obtain a manganese sulfate solution, re-preparing the impurity removal agent and the extraction agent from the by-product through a stripping agent, and returning the impurity removal agent and the extraction agent to a process system for cyclic utilization. The by-product manganese salt is used as a manganese source, the raw material price is low, wastewater and waste residues generated in the production period can be returned to the technological process for reuse, the cost is saved, the environmental pollution is small, the obtained product manganese sulfate solution can reach the battery-grade manganese sulfate standard, and the fluorine content of the solution is greatly reduced and is obviously superior to that of an existing process.

Description

Technical Field

[0001] This invention relates to the field of manganese sulfate technology for manganese tetroxide materials, specifically a low-cost method for removing impurities from manganese salts, a byproduct. Background Technology

[0002] Manganese sulfate is a traditional manganese salt product with a wide range of applications and plays an important role in manganese-based products. It is an important industrial intermediate product for the production of other manganese oxides and manganese salts. Battery-grade high-purity manganese sulfate is mainly used to prepare precursors for ternary cathode materials (lithium nickel cobalt manganese oxide) in lithium batteries, and is also a basic raw material for the preparation of battery-grade high-purity manganese tetroxide and high-purity manganese dioxide.

[0003] Manganese tetroxide is an important raw material for the electronics and battery industries. Currently, most manufacturers of manganese tetroxide materials use manganese salt precipitation oxidation method and metallic manganese suspension oxidation method (see CN1252385, CN1252386, CN103058280A, etc.).

[0004] With the rapid development of the battery industry, the amount of manganese and other by-product manganese salts generated from lithium battery recycling is increasing, bringing enormous economic and environmental pressures to the whole society.

[0005] Therefore, developing a process route for preparing manganese tetroxide materials using byproduct manganese salts as the manganese source through precipitation oxidation is an inevitable trend. However, due to the high impurity content of the byproduct manganese salts, how to rationally utilize these byproduct manganese salts is a pressing problem that needs to be solved in the industry. Current technologies mostly use SDD, sodium fluoride, and calcium chloride to remove impurities and obtain the required manganese sulfate. However, manganese sulfate contains a large amount of fluorine, which needs further reduction, and the process is costly and generates fluorine-containing waste residue, causing environmental pollution. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the inventors, through practice and summarization, derived the technical solution of this invention, which adopts the following technical solution:

[0007] A low-cost method for removing manganese salts as a byproduct, comprising the following steps:

[0008] (1) Take the by-product manganese salt solution and place it in a reaction vessel. Heat it in a water bath to the specified temperature, turn on the stirring and keep it at a certain speed. Add a certain amount of precipitant, stir for a certain time, and then filter to obtain the first filtrate.

[0009] (2) Take all the filtrate from (1) and place it in a reaction vessel. Heat it in a water bath to the specified temperature, turn on the stirring and keep it at a certain speed. Add a certain amount of impurity remover, stir for a certain time, and then filter to obtain the secondary filtrate.

[0010] (3) Take all the filtrate from (2) and place it in a reaction vessel. Heat it in a water bath to the specified temperature, turn on the stirring and keep it at a certain speed. Add a certain amount of extractant, stir for a certain time, shake and separate the phases for a certain time, and then separate the oil and water through a separatory funnel. The aqueous phase is a manganese sulfate solution.

[0011] (4) Place the oil phase obtained in (3) in a reaction vessel, heat it to the specified temperature in a water bath, turn on the stirring and keep a certain speed, add a certain amount of back-extraction agent, stir for a period of time, filter, and return the filter residue to (2) for continued use. After the liquid phase is shaken and separated for a certain time, oil and water are separated by a separatory funnel, and the oil phase is returned to step (3) for continued use. The aqueous phase is used to prepare back-extraction agent for continued use.

[0012] Preferably, in step (1), the specified temperature is 55-70℃;

[0013] Preferably, the specified rotational speed is 300-500 rpm;

[0014] Preferably, the certain amount of flocculant is barium hydroxide added at a concentration of 0.1-10 g / L;

[0015] Preferably, the stirring time is 1.5-2 hours.

[0016] Preferably, in step (2), the specified temperature is 65-80℃;

[0017] Preferably, in step (2), the certain rotational speed is 650-800 rpm;

[0018] Preferably, in step (2), the certain amount of impurity removal agent is manganese fluoride with an addition amount of 0.1-10 g / L;

[0019] Preferably, in step (2), the stirring time is 3-5 hours.

[0020] Preferably, in step (3), the specified temperature is room temperature;

[0021] Preferably, in step (3), the certain rotational speed is 250-320 rpm;

[0022] Preferably, in step (3), the certain amount of extractant is a mixed organic phase of tributyl phosphate and 260 sulfonated kerosene, with the volume ratio of tributyl phosphate in the mixed organic phase being 20-40%, and the amount of extractant being 0.1-1 times the amount of secondary filtrate.

[0023] In step (3), the stirring time is 15-25 minutes;

[0024] In step (3), the oscillation phase separation time is 15-25 min.

[0025] Preferably, in step (4), the specified temperature is 55-65℃;

[0026] Preferably, in step (4), the certain rotational speed is 700-900 rpm;

[0027] Preferably, in step (4), the certain amount of stripping agent is an aqueous suspension with a manganese content of 10 g / L, and the amount of stripping agent is 0.1-1 times the amount of oil phase;

[0028] Preferably, in step (4), the stirring time is 2-4 hours;

[0029] Preferably, in step (4), the oscillation phase separation time is 15-30 min.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention involves treating the byproduct manganese salt solution sequentially with a flocculant, a purifying agent, and an extractant to obtain a manganese sulfate solution that meets the requirements of the HG / T 4823-2023 standard. During the preparation process, an extractant is used to obtain a fluorine-containing organic phase and an aqueous phase of manganese sulfate. The fluorine-containing organic phase is then used to extract fluorine from the organic phase under the action of a back-extraction agent, and a purifying agent is produced. This method saves costs while obtaining higher quality manganese sulfate, and also solves the problems of fluorine-containing waste residue caused by traditional defluorination methods.

[0032] The manganese source used in this invention is manganese salt, a byproduct. The raw material price is low, and the wastewater and waste residue generated during production can be returned to the process for reuse, saving costs and causing less environmental pollution. The resulting manganese sulfate solution can meet the battery-grade manganese sulfate standard, and the fluoride content of the solution is significantly reduced, which is significantly better than the existing process. Attached Figure Description

[0033] Figure 1 This is a flowchart of the low-cost impurity removal process for the manganese salt byproduct of this invention. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0035] Example 1: A low-cost method for removing impurities from manganese salt by-products, the preparation method comprising the following steps:

[0036] (1) Take 0.5L of the by-product manganese salt solution and place it in the reaction vessel. After heating it in a water bath to 60°C, turn on the stirring and keep the speed at 500rpm. Add 10g of flocculant and stir for 2h. Filter and take the filtrate for step (2).

[0037] (2) Take all the filtrate from (1) and place it in a reaction vessel. Heat it in a water bath to 70°C, turn on the stirrer and keep the speed at 700 rpm. Add 1g of impurity removal agent, stir for 4 hours, filter and take the second filtrate for step (3).

[0038] (3) Take all the filtrate from (2) and place it in a reaction vessel. Turn on the stirrer at room temperature and keep the speed at 300 rpm. Add 0.5 L of extractant. Stir for 20 min, then shake and separate the phases for 20 min. Separate the oil and water through a separatory funnel. The aqueous phase is a manganese sulfate solution.

[0039] (4) Place the oil phase obtained in (3) in a reaction vessel, heat it to 60°C in a water bath, turn on the stirrer and keep the speed at 800 rpm, add 0.5 L of stripping agent, stir for 20 min, filter, and return the filter residue to step (2) for continued use. After the liquid phase is shaken and separated for a certain period of time, separate the oil and water through a separatory funnel. Return the oil phase to step (3) for continued use, and continue to prepare stripping agent for the aqueous phase.

[0040] Example 2: A low-cost method for removing impurities from manganese salt by-products, the preparation method comprising the following steps:

[0041] (1) Take 0.5L of the by-product manganese salt solution and place it in the reaction vessel. After heating in a water bath to 60°C, turn on the stirrer and keep the speed at 500rpm. Add 5g of flocculant and stir for 2 hours. Then filter and take the filtrate for step (2).

[0042] (2) Take all the filtrate from (1) and place it in a reaction vessel. Heat it in a water bath to 70°C, turn on the stirrer and keep the speed at 700 rpm. Add 5g of impurity removal agent, stir for 4 hours, filter and take the filtrate for step (3).

[0043] (3) Take all the filtrate from (2) and place it in a reaction vessel. Turn on the stirrer at room temperature and keep the speed at 300 rpm. Add 0.3 L of extractant. Stir for 20 min, then shake and separate the phases for 20 min. Separate the oil and water through a separatory funnel. The aqueous phase is manganese sulfate solution.

[0044] (4) Place the oil phase obtained in (3) in a reaction vessel, heat it to 60°C in a water bath, turn on the stirrer and keep the speed at 800 rpm, add 0.5 L of stripping agent, stir for 20 min, filter, and return the filter residue to step (2) for continued use. After the liquid phase is shaken and separated for a certain period of time, separate the oil and water through a separatory funnel. Return the oil phase to step (3) for continued use, and continue to prepare stripping agent for the aqueous phase.

[0045] Comparative Example 1:

[0046] (1) Take 1L of the byproduct manganese salt solution and put it in a 1L beaker. Heat it in a water bath at 60°C, turn on the stirrer and keep the speed at 500rpm. Add 2g of SDD and stir for 2h. Filter the solution and take the filtrate for step (2).

[0047] (2) Take all the filtrate from (1) and put it into a 1L beaker. Heat it in a water bath to 80°C, turn on the stirrer and keep the speed at 700 rpm. Add 7.5g of sodium fluoride, stir for 12 hours, and then filter to obtain a fluorinated manganese sulfate solution.

[0048] (3) Add 2g of calcium chloride to the fluorine-containing manganese sulfate solution in (2), turn on the stirrer and keep the speed at 700rpm. After stirring for 2 hours, filter to obtain a qualified manganese sulfate solution.

[0049] The chemical properties and waste residue of manganese sulfate obtained in Examples 1-2 and Comparative Example 1 were tested, and the results are shown in Table 1.

[0050] Table 1 Chemical properties of manganese sulfate solution

[0051]

[0052] The results show that the manganese sulfate solution prepared by the method of the present invention has high purity and meets the requirements of HG / T 4823-2023 standard.

[0053] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. The substitutions may be replacements of some structures, devices, or method steps, or they may be complete technical solutions. Equivalent substitutions or modifications made to the technical solutions and inventive concepts of the present invention should all be covered within the scope of protection of the present invention.

Claims

1. A low-cost method for removing manganese salts as a byproduct, characterized in that, The impurity removal steps are as follows: (1) Take the by-product manganese salt solution and place it in a reaction vessel. Heat it in a water bath to the specified temperature, turn on the stirring and keep it at a certain speed. Add a certain amount of precipitant, stir for a certain time, and then filter to obtain the first filtrate. (2) Take all the filtrate from (1) and place it in a reaction vessel. Heat it in a water bath to the specified temperature, turn on the stirring and keep it at a certain speed. Add a certain amount of impurity remover, stir for a certain time, and then filter to obtain the secondary filtrate. (3) Take all the filtrate from (2) and place it in a reaction vessel. Heat it in a water bath to the specified temperature, turn on the stirring and keep it at a certain speed. Add a certain amount of extractant, stir for a certain time, shake and separate the phases for a certain time, and then separate the oil and water through a separatory funnel. The aqueous phase is a manganese sulfate solution. (4) Place the oil phase obtained in (3) in a reaction vessel, heat it to the specified temperature in a water bath, turn on the stirring and keep a certain speed, add a certain amount of back-extraction agent, stir for a period of time, filter, and return the filter residue to (2) for continued use. After the liquid phase is shaken and separated for a certain time, oil and water are separated by a separatory funnel, and the oil phase is returned to step (3) for continued use. The aqueous phase is used to prepare back-extraction agent for continued use.

2. The low-cost method for removing manganese salt by-products according to claim 1, characterized in that, In step (1), the specified temperature is 55-70℃; The specified rotational speed is 300-500 rpm; The certain amount of flocculant is barium hydroxide added at a concentration of 0.1-10 g / L; The stirring time is 1.5-2 hours.

3. The low-cost method for removing manganese salt by-products according to claim 1, characterized in that, In step (2), the specified temperature is 65-80℃; In step (2), the certain rotational speed is 650-800 rpm; In step (2), the certain amount of impurity removal agent is manganese fluoride with an addition amount of 0.1-10 g / L; In step (2), the stirring time is 3-5 hours.

4. The low-cost method for removing manganese salt by-products according to claim 1, characterized in that, In step (3), the specified temperature is room temperature; In step (3), the certain rotational speed is 250-320 rpm; In step (3), the certain amount of extractant is a mixed organic phase of tributyl phosphate and 260 sulfonated kerosene, with tributyl phosphate accounting for 20-40% of the volume in the mixed organic phase, and the amount of extractant used is 0.1-1 times the amount of secondary filtrate. In step (3), the stirring time is 15-25 minutes; In step (3), the oscillation phase separation time is 15-25 min.

5. A low-cost method for removing manganese salt byproducts according to claim 1, characterized in that, In step (4), the specified temperature is 55-65℃; In step (4), the certain rotational speed is 700-900 rpm; In step (4), the certain amount of stripping agent is an aqueous suspension with a manganese content of 10 g / L, and the amount of stripping agent used is 0.1-1 times the amount of oil phase. In step (4), the stirring time is 2-4 hours; In step (4), the oscillation phase separation time is 15-30 min.

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