Preparation method of alkaline manganese battery indium oxide

Abstract

The invention provides a preparation method of indium oxide of an alkaline manganese battery. The preparation method comprises the following steps: adding hydrochloric acid into metal indium to react to obtain an indium chloride solution; adding the indium chloride solution into a reaction kettle, adding a potassium hydroxide solution into the indium chloride solution from the periphery of the inner wall of the reaction kettle, and stirring for reaction to obtain an indium hydroxide precursor; and filtering, washing, drying and calcining the indium hydroxide precursor to obtain indium oxide powder. The preparation method of alkaline manganese battery indium oxide provided by the invention is simple in process, environment-friendly, high in product quality, low in production cost, efficient in production and capable of realizing large-scale production.

Description

Technical Field

[0001] The invention relates to the technical field of indium oxide preparation, and in particular to a method for preparing indium oxide for an alkali manganese battery. Background Art

[0002] Indium hydroxide is a white powder, and indium oxide is a light yellow powder, and they are widely used. Among them, they can be used to replace mercury in alkaline manganese batteries. Indium hydroxide and / or indium oxide can inhibit the precipitation of hydrogen during the use of alkaline manganese batteries, and act as corrosion inhibitors and disappearing agents. In addition, indium oxide is also a very important n-type wide bandgap transparent semiconductor material, which has both high visible light transmittance and high conductivity. Due to its excellent performance, indium oxide-based magnetron sputtering ceramic targets (mainly doped SnO, ZnO, etc.) have been widely used in solar cells, optoelectronic devices, liquid crystal displays, etc. As an additive and main raw material required for the preparation of the above materials, indium oxide powder requires high purity, good dispersibility, fine and uniform particle size, and large-scale production is a necessary condition.

[0003] There are many methods for preparing indium oxide powder, such as neutralization precipitation, electrolysis, arc gas phase oxidation, etc.

[0004] Among them, the neutralization precipitation method is currently a widely used method for preparing indium oxide powder. Indium nitrate is usually neutralized with ammonia water to generate indium hydroxide precipitation, and then dried and roasted to obtain indium oxide powder. This method is prone to produce a large amount of nitrogen oxide tail gas and ammonia nitrogen wastewater during the production process. The tail gas and wastewater emissions are large, the treatment cost is high, and the impact on the environment is large. In addition, nitric acid and ammonia water are very dangerous during use, storage, and transportation.

[0005] The electrolysis method is to electrolyze metallic indium in an electrolyte to produce indium hydroxide precipitate, which is then dried and calcined to obtain indium oxide powder. This method can reduce the amount of nitrogen-containing wastewater generated during the production process and improve environmental friendliness. However, the fine indium hydroxide powder produced by the electrolysis method is easy to agglomerate, and the particle size distribution range of the agglomerated particles becomes wider, resulting in poor uniformity of the powder particles, which has a greater impact on battery performance. In addition, this method has low electrical efficiency, small production capacity, and low production efficiency, and is not suitable for large-scale production.

[0006] The arc gas phase oxidation method uses an electric arc to melt and vaporize metallic indium. The vaporized metal reacts with oxygen to generate indium oxide powder, which can be collected to obtain indium oxide powder. This method does not produce wastewater and is environmentally friendly. However, the indium oxide powder produced by this method has a wide particle size distribution range, poor morphology consistency, and low sintering activity.

[0007] Therefore, there is an urgent need for a method for preparing indium oxide for alkaline manganese batteries that has simple process, environmental friendliness, high product quality, low production cost, high production efficiency and scalable production. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a method for preparing indium oxide for alkaline manganese batteries which has simple process, environmental friendliness, high product quality, low production cost, high production efficiency and large-scale production.

[0009] In order to solve the above technical problems, the present invention provides a method for preparing indium oxide for alkaline manganese battery, comprising the following steps:

[0010] Metal indium reacts with hydrochloric acid to produce indium chloride solution;

[0011] Adding an indium chloride solution into a reaction kettle, adding a potassium hydroxide solution to the indium chloride solution from the inner wall of the reaction kettle, and stirring to react to obtain an indium hydroxide precursor;

[0012] The indium hydroxide precursor is filtered, washed, dried and calcined to obtain indium oxide powder.

[0013] Furthermore, the metallic indium is metallic indium with a purity of 4N grade.

[0014] Furthermore, the metal indium is sponge indium, honeycomb indium flower or indium powder.

[0015] Furthermore, the hydrochloric acid is a hydrochloric acid solution with a mass percentage concentration of 36-38%.

[0016] Furthermore, the molar concentration of indium in the indium chloride solution is 1.0-1.2 mol / L.

[0017] Furthermore, the reactor comprises a reactor body arranged in a constant temperature circulating water bath, a spiral polytetrafluoroethylene tube is fixedly arranged on the inner wall of the reactor body, liquid outlet holes are evenly arranged on the side of the polytetrafluoroethylene tube facing away from the inner wall of the reactor, a liquid inlet connected to the polytetrafluoroethylene tube is arranged on the top of the reactor, and an agitator is arranged in the reactor.

[0018] Furthermore, a water bath inlet is arranged at the top of the constant temperature circulating water bath, the water bath inlet is connected to the hot water delivery pipe, a circulation pump and a heating and temperature controller are arranged on the hot water delivery pipe, and a water bath outlet and an overflow port are respectively arranged at the bottom and upper side wall of the constant temperature circulating water bath.

[0019] Furthermore, the potassium hydroxide solution enters the reaction kettle through each liquid outlet hole on the tetrafluoroplastic tube, the molar concentration of the potassium hydroxide solution is 9-12 mol / L, the potassium hydroxide solution is added into the tetrafluoroplastic tube through a metering pump, and the addition rate of the potassium hydroxide solution is 10-15 mL / min.

[0020] Furthermore, the indium chloride solution and the potassium hydroxide solution are continuously stirred during the reaction, the solution end point pH is 6.0-6.5, and the reaction temperature is 60°C-65°C.

[0021] Furthermore, the calcination temperature of the indium hydroxide precursor is 600° C.-800° C., the particle size of the indium oxide powder obtained after the indium hydroxide precursor is calcined and cooled is 4-6 μm, and the contents of chloride ions and potassium ions in the indium oxide powder are both not higher than 0.1%.

[0022] Since the specific gravity of the indium chloride solution is greater than that of the potassium hydroxide solution, during the reaction of the indium chloride solution and the potassium hydroxide solution to synthesize indium hydroxide, stratification and temperature unevenness of the two solutions are likely to occur, resulting in insufficient contact between the indium chloride solution and the potassium hydroxide solution and incomplete reaction, which affects the reaction effect of the two.

[0023] Therefore, the present invention provides a method for preparing indium oxide for alkaline manganese battery, wherein a tetrafluoro plastic tube is spirally arranged on the inner wall of the reactor, and liquid outlet holes are evenly arranged on the side of the tetrafluoro plastic tube facing away from the inner wall of the reactor, so that when the potassium hydroxide solution enters the reactor from the tetrafluoro plastic tube, it can enter the indium chloride solution from various gradient positions around the upper and lower sides of the reactor, which not only allows the potassium hydroxide solution and the indium chloride solution to be fully in contact, but also ensures that the upper and lower temperatures of the solution in the reactor are consistent, thereby not only enabling the reaction to be thorough, but also ensuring that the generated indium hydroxide precursor has good uniformity of particle size, greatly improving the reaction efficiency and reaction effect of the potassium hydroxide solution and the indium chloride solution. Not only can the production efficiency be improved, but also the quality of the product can be improved.

[0024] Moreover, the method for preparing indium oxide for alkaline manganese battery provided by the present invention only needs to react metallic indium with hydrochloric acid to obtain an indium chloride solution, then react the indium chloride solution with a potassium hydroxide solution to obtain an indium hydroxide precursor, and finally filter, wash, dry, and calcine the indium hydroxide precursor to obtain indium oxide powder. The process flow is simple and easy to implement. Moreover, the raw materials for reacting with metallic indium are selected from hydrochloric acid and potassium hydroxide, which are widely available and inexpensive, and can also greatly reduce production costs and improve economic benefits. In addition, the present invention uses metallic indium, hydrochloric acid and potassium hydroxide as raw materials to prepare indium oxide. During the entire preparation, storage and transportation process, no nitrogen oxide waste gas and ammonia nitrogen wastewater are generated, and the impact on the environment is small. It is environmentally friendly and suitable for large-scale production.

[0025] At the same time, the present invention provides a method for preparing indium oxide for an alkaline manganese battery, in which hydrochloric acid and potassium hydroxide are used as raw materials to prepare indium oxide. Although the prepared indium oxide product contains no more than 0.1% of chloride ions and potassium ions, the electrolyte of the alkaline manganese battery itself contains 30-50% of potassium chloride. Therefore, the indium oxide product prepared by the present invention does not affect the performance of the alkaline manganese battery, the quality of the prepared indium oxide product is relatively high, and the purity of the prepared indium oxide product can reach more than 98.6%. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A flow chart of a method for preparing indium oxide for an alkaline manganese battery provided in an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of the structure of a reaction kettle in a method for preparing indium oxide for an alkaline manganese battery provided in an embodiment of the present invention.

[0028] In the figure:

[0029] 1. Agitator; 2. Water bath inlet; 3. PTFE tube; 4. Constant temperature circulating water bath; 5. Kettle body; 6. Circulation pump; 7. Water bath outlet; 8. Overflow port; 9. Hot water delivery pipe; 10. Heating and temperature controller. DETAILED DESCRIPTION

[0030] See also Figure 1 The present invention provides a method for preparing indium oxide for an alkaline manganese battery, comprising the following steps:

[0031] Step 1) metallic indium is reacted with hydrochloric acid to obtain an indium chloride solution.

[0032] In order to improve the purity of the finally obtained indium oxide, the metal indium uses a 4N grade of purity, that is, a 99.99% purity of metal indium.

[0033] The metal indium can be in the form of sponge indium, honeycomb indium flower, or indium powder.

[0034] The hydrochloric acid reacting with the metal indium is a hydrochloric acid solution with a mass percentage concentration of 36-38%.

[0035] The molar concentration of indium in the indium chloride solution obtained after the reaction of metallic indium and hydrochloric acid, that is, the molar concentration of indium chloride, is 1.0-1.2 mol / L.

[0036] Step 2) Add indium chloride solution into a reactor, add potassium hydroxide solution into the indium chloride solution from the inner wall of the reactor, and stir to react to obtain an indium hydroxide precursor.

[0037] Since the specific gravity of the indium chloride solution is greater than that of the potassium hydroxide solution, during the reaction of the indium chloride solution and the potassium hydroxide solution to synthesize indium hydroxide, stratification and temperature unevenness of the two solutions are likely to occur, resulting in insufficient contact between the indium chloride solution and the potassium hydroxide solution and incomplete reaction, which affects the reaction effect of the two.

[0038] Therefore, the present invention adds the indium chloride solution into the reaction kettle, and adds the potassium hydroxide solution into the indium chloride solution from the upper and lower sides of the inner wall of the reaction kettle, so that the potassium hydroxide can be mixed with the indium chloride at various gradient positions in the indium chloride solution in the reaction kettle to react more thoroughly.

[0039] See also Figure 2 The reactor provided by the present invention comprises a kettle body 5 arranged in a constant temperature circulating water bath 4. A spiral PTFE tube 3 is fixedly arranged on the inner wall of the kettle body 5, and the PTFE tube 3 is evenly arranged around the inner wall of the kettle body 5 from top to bottom in the kettle body 5. In addition, a series of liquid outlets are evenly arranged on the side of the PTFE tube 3 facing away from the inner wall of the kettle body 5, and a liquid inlet connected to the PTFE tube 3 is arranged on the top of the kettle body 5. The potassium hydroxide solution enters the PTFE tube 3 from the liquid inlet on the top of the kettle body 5, and then is sprayed into the indium chloride solution from various parts of the indium chloride solution through various liquid outlets on the PTFE tube 3. At the same time, an agitator 1 is arranged in the kettle body 5 of the reactor. Under the stirring action of the agitator 1, the potassium hydroxide solution can be fully mixed with the indium chloride solution, so that the two solutions are fully in contact, and the upper and lower temperatures of the solutions in the reactor can be ensured to be consistent, so that the reaction of the two is thorough, thereby avoiding the problem of incomplete reaction of the potassium hydroxide solution and the indium chloride solution due to stratification due to different specific gravities. Therefore, the method for preparing indium oxide for alkaline manganese battery provided by the present invention can greatly improve the reaction efficiency and reaction effect of potassium hydroxide solution and indium chloride solution, which can not only improve production efficiency but also improve product quality.

[0040] Among them, a water bath inlet 2 is arranged on the top of the constant temperature circulating water bath 4, and the water bath inlet 2 is connected to the hot water delivery pipe 9. The hot water delivery pipe 9 is provided with a circulation pump 6 and a heating and temperature controller 10, and a water bath outlet 7 and an overflow port 8 are respectively arranged on the bottom and the upper side wall of the constant temperature circulating water bath 4.

[0041] As a specific embodiment of the present invention, the potassium hydroxide solution enters the reactor body 5 through each liquid outlet hole on the tetrafluoroplastic tube 3. The molar concentration of the potassium hydroxide solution is 9-12 mol / L, and in order to promote the potassium hydroxide solution to quantitatively enter the tetrafluoroplastic tube 3 and enter the indium chloride solution from each liquid outlet hole on the tetrafluoroplastic tube 3, the potassium hydroxide solution is added into the tetrafluoroplastic tube 3 through a metering pump. Among them, the potassium hydroxide solution is promoted to have sufficient power to spray into the indium chloride solution and fully mix with the indium chloride, and the addition rate of the potassium hydroxide solution is controlled to be 10-15 mL / min.

[0042] In order to ensure that the indium chloride solution and the potassium hydroxide solution can be fully mixed without stratification, the indium chloride solution and the potassium hydroxide solution are continuously stirred by the stirrer 1 during the reaction, and the end point pH of the solution is 6.0-6.5.

[0043] Furthermore, the kettle 5 is heated in a water bath by hot water in a constant temperature circulating water bath 4, and the temperature of the reaction between the indium chloride solution and the potassium hydroxide solution is controlled to be 60° C.-65° C. At this reaction temperature, the indium chloride solution and the potassium hydroxide solution can react fully to obtain a high-quality indium hydroxide precursor.

[0044] Step 3) filtering, washing, drying and calcining the indium hydroxide precursor to obtain indium oxide powder.

[0045] The calcination temperature of the indium hydroxide precursor is 600° C.-800° C., the particle size of the indium oxide powder obtained after the indium hydroxide precursor is calcined and cooled is 4-6 μm, and the contents of chloride ions and potassium ions in the indium oxide powder are both not higher than 0.1%.

[0046] Although the prepared indium oxide product contains no more than 0.1% of chloride ions and potassium ions, since the electrolyte of the alkaline manganese battery itself contains 30-50% of potassium chloride, the indium oxide product prepared by the present invention does not affect the performance of the alkaline manganese battery, and the quality of the prepared indium oxide product is relatively high, and its purity can reach more than 98.6%.

[0047] The present invention provides a method for preparing indium oxide for alkaline manganese battery, which only requires reacting metallic indium with hydrochloric acid to obtain an indium chloride solution, then reacting the indium chloride solution with a potassium hydroxide solution to obtain an indium hydroxide precursor, and finally filtering, washing, drying, and calcining the indium hydroxide precursor to obtain indium oxide powder. The process flow is simple and easy to implement. Moreover, the raw materials for reacting with metallic indium are selected from hydrochloric acid and potassium hydroxide, which are widely available and inexpensive, and can also greatly reduce production costs and improve economic benefits. In addition, the present invention uses metallic indium, hydrochloric acid and potassium hydroxide as raw materials to prepare indium oxide. During the entire preparation, storage and transportation process, no nitrogen oxide waste gas and ammonia nitrogen wastewater are generated, and the impact on the environment is small, environmentally friendly, and suitable for large-scale production.

[0048] The following is a specific description of the method for preparing indium oxide for alkaline manganese battery provided by the present invention through examples.

[0049] Example 1

[0050] 500 g of 4N pure sponge indium reacts with hydrochloric acid, that is, about 500 mL of 37% hydrochloric acid is slowly added under constant stirring, and heated and an appropriate amount of pure water is added to obtain an indium chloride solution with an indium molar concentration of 1.0 mol / L.

[0051] The indium chloride solution was placed in a synthesis reactor device, 732g of potassium hydroxide was dissolved in pure water to obtain 1.45L of 9mol / l potassium hydroxide solution, which was pumped into the synthesis reactor with a metering pump at a flow rate of 10ml / min. At the same time, stirring was started at a speed of 250rpm, the reaction temperature was controlled at 60°C, and the endpoint pH was controlled at 6.0. After the reaction was completed, an indium hydroxide precursor was obtained.

[0052] The indium hydroxide precursor is filtered, washed, dried and calcined to obtain indium oxide powder, the powder particle size d50 of which is 4.01um, and the weight percentages of chlorine and potassium are 0.08% and 0.06% respectively.

[0053] The purity of the obtained indium oxide powder is as high as 98.6%.

[0054] Example 2

[0055] 500g of honeycomb indium flower with a purity of 4N was reacted with hydrochloric acid, that is, about 500mL of hydrochloric acid with a concentration (wt%) of 37% was slowly added under constant stirring, and heated and added with an appropriate amount of pure water to obtain an indium chloride solution with an indium concentration of 1.1mol / L.

[0056] The indium chloride solution was placed in a synthesis reactor device, 732g of potassium hydroxide was dissolved in pure water to obtain 1.25L of a 10.5mol / l solution, which was pumped into the reactor at a flow rate of 12ml / min using a metering pump. At the same time, stirring was started at a speed of 250rpm, the reaction temperature was controlled at 65°C, and the endpoint pH was controlled at 6.0. After the reaction was completed, an indium hydroxide precursor was obtained.

[0057] The indium hydroxide precursor is filtered, washed, dried and calcined to obtain indium oxide, whose d50 is 5.06um, and the weight percentages of chlorine and potassium are 0.07% and 0.065% respectively.

[0058] The purity of the obtained indium oxide powder is as high as 99.4%.

[0059] Example 3

[0060] 500 g of indium powder with a purity of 4N was reacted with hydrochloric acid, that is, about 500 mL of hydrochloric acid with a concentration (wt%) of 37% was slowly added under constant stirring, and heated and added with an appropriate amount of pure water to obtain an indium chloride solution with an indium concentration of 1.2 mol / L.

[0061] The indium chloride solution was placed in a synthesis reactor device, 742g of potassium hydroxide was dissolved in pure water to obtain 1.1L of a 12mol / l solution, which was pumped into the reactor at a flow rate of 15ml / min using a metering pump. At the same time, stirring was started at a speed of 250rpm, the reaction temperature was controlled at 65°C, the endpoint pH was controlled at 6.5, and the indium hydroxide precursor was obtained after the reaction was completed.

[0062] The indium hydroxide precursor is filtered, washed, dried and calcined to obtain indium oxide, the powder particle size d50 of which is 5.81um, and the weight percentages of chlorine and potassium are 0.072% and 0.068% respectively.

[0063] The purity of the obtained indium oxide powder is as high as 98.9%.

[0064] It can be seen from the above examples that the preparation method of indium oxide for alkaline manganese battery provided by the present invention obtains indium oxide for alkaline manganese battery with high product quality, i.e., purity of more than 98.6%, through a simple production process, and the production is efficient. In addition, since the raw materials used in the present invention are cheap and easily available hydrochloric acid and potassium hydroxide, not only the production cost is low and the economic benefit is high, but also no pollutants such as nitrogen oxide waste gas and ammonia nitrogen waste water are generated during the production process, which is environmentally friendly. Therefore, the preparation method of indium oxide for alkaline manganese battery provided by the present invention is suitable for large-scale production and is worthy of promotion and application.

[0065] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing indium oxide for alkaline manganese battery, characterized in that: The steps include: Metal indium reacts with hydrochloric acid to produce indium chloride solution; Adding an indium chloride solution into a reaction kettle, adding a potassium hydroxide solution to the indium chloride solution from the inner wall of the reaction kettle, and stirring to react to obtain an indium hydroxide precursor; The indium hydroxide precursor is filtered, washed, dried and calcined to obtain indium oxide powder.

2. The method for preparing indium oxide for alkaline manganese battery according to claim 1, characterized in that: The metal indium is of 4N purity grade.

3. The method for preparing indium oxide for alkaline manganese battery according to claim 2, characterized in that: The metal indium is sponge indium, honeycomb indium flower or indium powder.

4. The method for preparing indium oxide for alkaline manganese battery according to claim 1, characterized in that: The hydrochloric acid is a hydrochloric acid solution with a mass percentage concentration of 36-38%.

5. The method for preparing indium oxide for alkaline manganese battery according to claim 1, characterized in that: The molar concentration of indium in the indium chloride solution is 1.0-1.2 mol / L.

6. The method for preparing indium oxide for alkaline manganese battery according to claim 1, characterized in that: The reactor comprises a reactor body arranged in a constant temperature circulating water bath, a spiral PTFE tube is fixedly arranged on the inner wall of the reactor body, liquid outlet holes are evenly arranged on the side of the PTFE tube facing away from the inner wall of the reactor, a liquid inlet connected to the PTFE tube is arranged on the top of the reactor, and an agitator is arranged in the reactor.

7. The method for preparing indium oxide for alkaline manganese battery according to claim 6, characterized in that: A water bath inlet is arranged on the top of the constant temperature circulating water bath, and the water bath inlet is connected to a hot water delivery pipe, a circulation pump and a heating and temperature controller are arranged on the hot water delivery pipe, and a water bath outlet and an overflow port are arranged on the bottom and the upper side wall of the constant temperature circulating water bath respectively.

8. The method for preparing indium oxide for alkaline manganese battery according to claim 7, characterized in that: The potassium hydroxide solution enters the reaction kettle through each liquid outlet hole on the tetrafluoroplastic tube. The molar concentration of the potassium hydroxide solution is 9-12 mol / L. The potassium hydroxide solution is added into the tetrafluoroplastic tube through a metering pump. The addition rate of the potassium hydroxide solution is 10-15 mL / min.

9. The method for preparing indium oxide for alkaline manganese battery according to claim 8, characterized in that: The indium chloride solution and the potassium hydroxide solution are continuously stirred during the reaction, the end point pH of the solution is 6.0-6.5, and the reaction temperature is 60° C.-65° C.

10. The method for preparing indium oxide for alkaline manganese battery according to claim 1, characterized in that: The calcination temperature of the indium hydroxide precursor is 600° C.-800° C., the particle size of the indium oxide powder obtained after the indium hydroxide precursor is calcined and cooled is 4-6 μm, and the contents of chloride ions and potassium ions in the indium oxide powder are both not higher than 0.1%.

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