Method for preparing composite nickel protoxide by using three-fluid spray gun

Abstract

The invention relates to a method for preparing composite nickel protoxide by using a three-fluid spray gun, which comprises the following steps: (1) respectively adding iron-containing chloride, manganese-containing chloride, M-containing chloride and nickel chloride solution into two dissolving tanks according to the corresponding metal proportion of the product, heating, stirring and dissolving, a composite metal solution A and a composite metal solution B are obtained respectively; the metal ion concentration in the composite metal solution A and the composite metal solution B is at least maintained at 200g / L, and the temperature is maintained at 60 DEG C; m in the M-containing chloride refers to other metals except iron and manganese; and (2) sucking the composite metal solution A and the composite metal solution B into a three-fluid spray gun by utilizing negative pressure generated by air flowing through a Venturi tube, mixing, and reacting in a spray pyrolysis system to obtain a corresponding composite nickel protoxide product and byproducts. According to the invention, the stability of the production system is ensured, the produced product is ensured to accord with the ratio of the composite nickel protoxide, and the product quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy and chemical engineering, and in particular to a method for preparing composite nickelous oxide by using a three-fluid spray gun. Background Art

[0002] Nickelous oxide (NiO) is an important inorganic compound with the appearance of gray-green powdery solid. It is widely used in the production of nickel-zinc ferrite, catalysts, semiconductors, ceramic colorants and important industrial raw materials for secondary batteries. In recent years, with the rapid development of the new energy battery industry, the application of nickelous oxide in the battery industry, especially in the positive electrode materials of sodium-ion batteries, has also been increasing. There is a certain gap between the specific surface area, particle size, looseness ratio, magnetic foreign matter and other indicators of the nickelous oxide products currently produced and the requirements of customers for the positive electrode materials of sodium-ion batteries. Therefore, the spray pyrolysis method is used to develop new nickelous oxide and its doped products to meet the new needs of the sodium battery material industry.

[0003] The existing technology is to directly produce composite nickelous oxide by spray pyrolysis. When preparing a single nickelous oxide product, a two-fluid spray gun is usually used. Only the nickel chloride solution and air are collected in the spray gun and then atomized by the atomizer and enter the roasting furnace for reaction to obtain a crude nickelous oxide product. The existing nickelous oxide spray pyrolysis technology only supports a single solution inlet, and it is difficult to ensure that the metal concentration in the solution is met. In addition, when the traditional two-fluid spray gun uses spray pyrolysis to prepare composite nickelous oxide, since the composite metal solution is prone to common ion effect, crystallization is easy to occur during the solution preparation stage, resulting in low liquid metal concentration and solution density before spray pyrolysis.

[0004] Therefore, in order to ensure the solution concentration of the liquid before spray pyrolysis, it is urgent to find a new liquid inlet technology to meet the metal concentration of the composite metal solution and ensure the stability of the spray pyrolysis process. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing composite nickelous oxide using a three-fluid spray gun, which satisfies the metal concentration of the composite metal solution and ensures the stability of the spray pyrolysis process.

[0006] In order to solve the above problems, the present invention provides a method for preparing composite nickelous oxide using a three-fluid spray gun, comprising the following steps: ⑴ Putting iron-containing chloride, manganese-containing chloride, M-containing chloride and nickel chloride solution into two dissolving tanks according to the corresponding metal ratio of the product, heating and stirring to dissolve, and respectively obtaining composite metal solution A and composite metal solution B; the metal ion concentration in the composite metal solution A and the composite metal solution B is maintained at least 200g / L, and the temperature is maintained at 60°C; M in the M-containing chloride refers to other metals except iron and manganese; (2) The composite metal solution A and the composite metal solution B are sucked into the three-fluid spray gun by using negative pressure generated by air flowing through the venturi tube. After mixing, they enter the spray pyrolysis system for reaction to obtain the corresponding composite nickelous oxide product and by-products. The by-products are recovered and used to produce nickel chloride solution.

[0007] The pressure of the air flow in step (2) is 6 kPa.

[0008] The three-fluid spray gun in step (2) includes a spray gun body; the tail of the spray gun body is provided with an air input port connected to the venturi tube, and the head is provided with a nozzle; the spray gun body near the outlet of the venturi tube is symmetrically provided with a composite metal solution A input port and a composite metal solution B input port, and the composite metal solution A input port and the composite metal solution B input port are respectively connected to the peristaltic pump through a hose; a mixing cavity is provided in front of the outlet of the venturi tube, and the mixing cavity is connected to the nozzle.

[0009] The flow rate of the peristaltic pump is matched with the ratio of the composite metal solution A and the composite metal solution B according to the product requirements.

[0010] The solution mixing residence time in the mixing cavity does not exceed 10s.

[0011] Compared with the prior art, the present invention has the following advantages: 1. The present invention adopts a three-fluid spray gun to make the solution mix quickly inside the spray gun, and the metal ions are mixed more evenly, avoiding the inability to prepare composite nickelous oxide by spray pyrolysis due to crystallization or precipitation caused by the complex interaction of high-concentration metal solutions. It not only ensures the stability of the production system, but also ensures that the produced products meet the ratio of composite nickelous oxide, thereby solving the problem of low liquid metal concentration and solution density before spray pyrolysis and improving product quality.

[0012] 2. The present invention realizes the conditions for composite nickelous oxide production by only changing the liquid inlet method, which is easy to transform and does not generate new operating costs. It is easy to train workers and no wastewater or waste gas is generated, which is green and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0014] Figure 1 It is a process flow chart of the present invention.

[0015] Figure 2 It is a schematic diagram of the three-fluid spray gun in the present invention.

[0016] In the figure: 1-spray gun body; 2-Venturi tube; 3-air inlet; 4-nozzle; 5-composite metal solution A inlet; 6-composite metal solution B inlet; 7-mixing cavity. DETAILED DESCRIPTION

[0017] like Figure 1 As shown, a method for preparing composite nickelous oxide using a three-fluid spray gun comprises the following steps: ⑴ Put iron-containing chloride, manganese-containing chloride, M-containing chloride and nickel chloride solution into two dissolving tanks according to the corresponding metal ratio of the product, heat and stir to dissolve, and stop stirring after the materials are completely dissolved to obtain composite metal solution A and composite metal solution B respectively; the metal ion concentrations in composite metal solution A and composite metal solution B are both maintained at at least 200 g / L, and the temperature is maintained at 60°C; M in M-containing chloride refers to metals other than iron and manganese.

[0018] When preparing, it is necessary to fully consider whether there will be a common ion effect between different metals, and at the same time consider the differences in metal ions produced in different proportions. When preparing the solution, the formation of crystals and precipitation should be avoided or reduced as much as possible, which will have a great impact on the subsequent liquid inlet and spray pyrolysis, and may cause the spray gun to be blocked, the solution to be mixed unevenly, or the overall spray pyrolysis effect to be poor. After dissolution, the solution needs to be kept at 60°C to prevent crystallization from precipitating in the solution. Therefore, in order to ensure the stability of the spray pyrolysis system, it is necessary to ensure that the metal ion concentration of both solutions is maintained at at least 200g / L.

[0019] (2) Using air at a pressure of 6 kPa to flow through the Venturi tube 2 to generate negative pressure, the composite metal solution A and the composite metal solution B are sucked into the three-fluid spray gun, and after mixing, they enter the spray pyrolysis system for reaction to obtain the corresponding composite nickelous oxide product and by-products, and the by-products are recovered for the production of nickel chloride solution.

[0020] Wherein: the three-fluid spray gun includes a spray gun body 1, such as Figure 2 As shown. The tail of the spray gun body 1 is provided with an air inlet 3 connected to the venturi tube 2, and the head is provided with a nozzle 4; the spray gun body 1 near the outlet of the venturi tube 2 is symmetrically provided with a composite metal solution A inlet 5 and a composite metal solution B inlet 6, and the composite metal solution A inlet 5 and the composite metal solution B inlet 6 are respectively connected to the peristaltic pump through a hose; a mixing cavity 7 is provided in front of the outlet of the venturi tube 2, and the mixing cavity 7 is connected to the nozzle 4.

[0021] A peristaltic pump is used to control the solution ratio and mix the solution inside the spray gun. The flow rate of the peristaltic pump is matched with the ratio of composite metal solution A and composite metal solution B according to the product requirements.

[0022] The solution mixing residence time in the mixing cavity 7 does not exceed 10 seconds to prevent the mixed solution from crystallizing and clogging the spray gun tip.

[0023] In the present invention, it is best to conduct a small-scale experiment before preparing the solution to find the optimal ratio of different metal solutions and reduce the error caused by the preparation process.

[0024] Example 1 Take the corresponding nickel chloride hexahydrate and manganese chloride tetrahydrate with Ni:Mn=1:1 (molar ratio) and put them into dissolution tank A for dissolution. After complete dissolution, measure the metal ion content and ratio of the solution, and measure the density of the solution to ensure that the solution is prepared accurately.

[0025] Take Fe:Mn=1:1 (molar ratio) and put the corresponding ferrous chloride tetrahydrate and manganese chloride tetrahydrate into dissolution tank B for dissolution. The subsequent operation is the same as that of dissolution tank 1.

[0026] The total metal ion concentration reaches above 200g / L and the solution density is maintained at 1.350g / cm 3 above.

[0027] A peristaltic pump was used to control solution A and solution B to enter the spray gun at a flow rate ratio (ml / ml) of 1:1, and then spray pyrolysis was performed to obtain composite nickelous oxide. The generated hydrogen chloride gas was absorbed by the spray tower and reused to produce nickel chloride solution. The physical and chemical properties of the obtained composite nickelous oxide were tested and found to be basically the same as the design, and the deviation of the content of each component was less than 5%.

[0028] Example 2 Take the corresponding nickel chloride hexahydrate and sodium chloride with Ni:Na=1:1 (molar ratio) and put them into dissolution tank A for dissolution. After complete dissolution, measure the metal ion content and ratio of the solution, and measure the density of the solution to ensure that the solution is accurately prepared.

[0029] Take the corresponding manganese chloride tetrahydrate and sodium chloride with Mn:Na=1:1 (molar ratio) and put them into dissolving tank B for dissolution. The subsequent operation is the same as that of dissolving tank 1.

[0030] The total metal ion concentration reaches above 200g / L and the solution density is maintained at 1.350g / cm 3 above.

[0031] A peristaltic pump was used to control solution A and solution B to enter the spray gun at a flow rate ratio (ml / ml) of 2:3, and then spray pyrolysis was performed to obtain composite nickelous oxide. The generated hydrogen chloride gas was absorbed by the spray tower and reused to produce nickel chloride solution. The physical and chemical properties of the obtained composite nickelous oxide were tested and found to be basically the same as the design, and the deviation of the content of each component was less than 10%.

[0032] Example 3 Take nickel chloride hexahydrate and put it into dissolving tank A for dissolution. After complete dissolution, measure the metal ion content of the solution and the density of the solution to ensure that the solution is accurately prepared.

[0033] Take manganese chloride tetrahydrate and put it into dissolving tank B for dissolution. The subsequent operation is the same as that of dissolving tank A.

[0034] The total metal ion concentration reaches above 240g / L and the solution density is maintained at 1.350g / cm 3 above.

[0035] A peristaltic pump was used to control solution A and solution B to enter the spray gun at a flow rate ratio (ml / ml) of 2:3, and then spray pyrolysis was performed to obtain composite nickelous oxide. The generated hydrogen chloride gas was absorbed by the spray tower and reused to produce nickel chloride solution. The physical and chemical properties of the obtained composite nickelous oxide were tested and found to be basically the same as the design, and the deviation of the content of each component was less than 10%.

Claims

1. A method for preparing composite nickelous oxide using a three-fluid spray gun, comprising the following steps: ⑴ Putting iron-containing chloride, manganese-containing chloride, M-containing chloride and nickel chloride solution into two dissolving tanks according to the corresponding metal ratio of the product, heating and stirring to dissolve, and respectively obtaining composite metal solution A and composite metal solution B; the metal ion concentration in the composite metal solution A and the composite metal solution B is maintained at least 200g / L, and the temperature is maintained at 60°C; M in the M-containing chloride refers to other metals except iron and manganese; (2) The composite metal solution A and the composite metal solution B are sucked into the interior of the three-fluid spray gun by using the negative pressure generated by the air flowing through the venturi tube (2). After mixing, the composite metal solution A and the composite metal solution B enter the spray pyrolysis system for reaction to obtain the corresponding composite nickelous oxide product and by-products. The by-products are recovered and used to produce nickel chloride solution.

2. A method for preparing composite nickelous oxide using a three-fluid spray gun as claimed in claim 1, characterized in that: The pressure of the air flow in step (2) is 6 kPa.

3. The method for preparing composite nickelous oxide using a three-fluid spray gun as claimed in claim 1, characterized in that: The three-fluid spray gun in step (2) comprises a spray gun body (1); the tail of the spray gun body (1) is provided with an air input port (3) connected to the venturi tube (2), and the head is provided with a nozzle (4); the spray gun body (1) near the outlet of the venturi tube (2) is symmetrically provided with a composite metal solution A input port (5) and a composite metal solution B input port (6), and the composite metal solution A input port (5) and the composite metal solution B input port (6) are respectively connected to a peristaltic pump through a hose; a mixing cavity (7) is provided in front of the outlet of the venturi tube (2), and the mixing cavity (7) is connected to the nozzle (4).

4. A method for preparing composite nickelous oxide using a three-fluid spray gun as claimed in claim 3, characterized in that: The flow rate of the peristaltic pump is matched with the ratio of the composite metal solution A and the composite metal solution B according to the product requirements.

5. The method for preparing composite nickelous oxide using a three-fluid spray gun as claimed in claim 3, characterized in that: The solution mixing residence time in the mixing cavity (7) does not exceed 10 seconds.

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