Method for preparing barium peroxide by ultrasonic-visible light synergetic dry method

Abstract

The invention discloses a method for preparing barium peroxide by an ultrasonic-visible light synergetic dry method, and belongs to the field of preparation of barium peroxide. A method for preparing barium peroxide by an ultrasonic-visible light synergetic dry method comprises the following steps: adding a barium hydroxide solid into a reactor, then adding a modified zinc oxide carrier, stirring for a certain time, turning on a visible light and ultrasonic wave generating device, continuously stirring, slowly adding atomized hydrogen peroxide, reacting for a certain time, and cooling to room temperature to obtain the barium peroxide. And drying to obtain a barium peroxide solid. The method can be used for solving the problems that the existing barium peroxide production process is complicated and has wastewater, and the barium peroxide prepared by the existing process is relatively low in purity and coarse in particle.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of barium peroxide preparation, more particularly, to a method for preparing barium peroxide by ultrasonic-visible light synergistic dry method. BACKGROUND

[0002] Barium peroxide has many uses, it is often used as an efficient environment-friendly bleaching agent and oxidizing agent, barium peroxide can also be used as a luminescent material, a catalyst, an important raw material for manufacturing pesticides and dyes, etc.

[0003] The existing synthesis method is a wet route: barium hydroxide or other barium salt is fully mixed and uniformly reacted with hydrogen peroxide in a large amount of aqueous system, the temperature is controlled within a certain range, after the reaction is completed, solid-liquid separation is carried out, and the wet product is dried to obtain the finished product. However, the preparation has the following disadvantages: 1. The process uses water as the reaction system medium to disperse barium hydroxide, and hydrogen peroxide is added dropwise, during which cold medium is introduced to control the temperature, and subsequent filtration, washing and drying are required. The process is complex, and a large amount of wastewater containing barium salt is generated; 2. In a large amount of aqueous environment, barium carbonate is easily produced with dissolved carbon dioxide, and impurities with multiple crystal waters are easily produced, and other hydration byproducts are also produced, which reduces the purity of the product; on the other hand, the reaction dynamic is relatively low, and the conversion rate is also low, resulting in low overall purity, and higher requirements for catalytic oxygenation and sterilization in the actual downstream use process; 3. The process is easily agglomerated in the aqueous environment, and is not easy to disperse, so that the particle size of the prepared barium peroxide is high; 4. The process produces a large amount of high-salinity wastewater after reaction, the treatment cost is high, and it is not environmentally friendly.

[0004] Therefore, it is urgent to provide a preparation method of barium peroxide with low cost and simple process, so that the prepared barium peroxide has high purity. SUMMARY

[0005] In view of the problems in the prior art, the purpose of the present application is to provide a method for preparing barium peroxide by ultrasonic-visible light synergistic dry method, which can solve the problems of complex process and wastewater in the existing production of barium peroxide, and also solve the problems of low purity and coarse particles of barium peroxide prepared by the existing process.

[0006] To solve the above problems, the technical scheme adopted by the present application is as follows.

[0007] A method for preparing barium peroxide by ultrasonic-visible light synergistic dry method, the preparation method is as follows: barium hydroxide solid is added to a reactor, then a modified zinc oxide carrier is added, stirring for a certain time, then the visible light and ultrasonic wave generating device are turned on, and continue to stir, while slowly adding atomized hydrogen peroxide, after a certain period of reaction, dry to obtain barium peroxide solid.

[0008] Further, the visible light source is an LED lamp, and the power is 20-100W. Preferably, the power of the LED lamp is 25W.

[0009] Further, the frequency of the ultrasonic wave is 20-120KHz. Preferably, the frequency of the ultrasonic wave is 40-60KHz.

[0010] Further, the adding amount of the modified zinc oxide carrier is 0.2-2% of the molar number of barium hydroxide; preferably, 1.2-2%.

[0011] Further, the mass concentration of the hydrogen peroxide is 30-70%, and the molar ratio of pure hydrogen peroxide to barium hydroxide in the hydrogen peroxide is 0.98-1.1:1. Preferably, the mass concentration of the hydrogen peroxide is 50%, and the molar ratio of pure hydrogen peroxide to barium hydroxide in the hydrogen peroxide is 1:1.

[0012] Further, the mixing and stirring time of the barium hydroxide and the modified zinc oxide carrier is 5min.

[0013] Further, the reaction temperature is 30-50℃, and the reaction time is 20-60min. Preferably, the reaction temperature is 30-40℃, and the reaction time is 30min.

[0014] Further, the drying temperature is 60-100℃, and the drying time is 20-60min.

[0015] Further, the modified zinc oxide carrier is a silver / zinc oxide active oxygen initiator.

[0016] Further, the preparation method of the silver / zinc oxide active oxygen initiator is as follows: zinc oxide and silver nitrate are added to deionized water, magnetically stirred, ammonia water is added to adjust the pH to 9-11, and then the precursor is obtained by continuing to stir for a certain time; then it is transferred to a four-fluorine high-pressure hydrothermal kettle for heating and holding reaction for a certain time, cooled to room temperature, and then filtered, washed and dried to obtain the silver / zinc oxide active oxygen initiator.

[0017] Further, the adding amount of the silver nitrate is 0.8-1.2% of the mass fraction of zinc oxide; preferably, 1%.

[0018] Further, the magnetic stirring temperature is 20-30℃, the stirring time is 5-10min, and the stirring time after adding ammonia water is 5-10min; the holding temperature in the high-pressure kettle is 140-180℃, and the reaction time is 8h.

[0019] Further, the drying temperature is 60-80℃, and the drying time is 10-30min.

[0020] Specifically, the preparation steps of barium peroxide are preferably as follows: S1: silver / zinc oxide active oxygen initiator: zinc oxide and 0.8-1.2% silver nitrate by mass of zinc oxide are added to deionized water, magnetic stirring, ammonia water is added to adjust the pH to 9-11, continue to stir for a certain time to obtain the initiator precursor; then it is transferred to a four-fluorine high-pressure hydrothermal kettle, heated and kept for a certain time, cooled to room temperature, filtered, washed and dried to obtain the silver / zinc oxide active oxygen initiator.

[0021] S2: barium hydroxide precursor: in a kettle reactor, add barium hydroxide solid, start stirring, speed 80-140 r / min, add 0.2-2% silver / zinc oxide active oxygen initiator by mole of barium hydroxide, to obtain the reaction precursor, wherein the silver / zinc oxide active oxygen initiator acts as an initiator of active oxygen free radicals under visible light.

[0022] S3: visible light irradiation-ultrasonic start: turn on the LED lamp device with a power of 25W, aim the visible light at the reactor, and the visible light promotes the silver / zinc oxide active oxygen initiator to initiate active oxygen free radicals; at the same time, place the reactor in the ultrasonic device and start the ultrasonic device, set the frequency to 20-120KHz, under the condition of continuous ultrasonic opening, on the one hand, a small amount of water in the system will appear cavitation effect, which will produce active point active oxygen free radicals locally, on the other hand, promote molecular vibration, and form finer particles at the micro level.

[0023] S4: hydrogen peroxide reaction: after visible light irradiation and ultrasonic start in the previous two steps, stir, and slowly add atomized hydrogen peroxide to the precursor, the mass concentration of hydrogen peroxide is 50%, the molar ratio of hydrogen peroxide to barium hydroxide in the hydrogen peroxide solution is 1:1, and the reaction temperature is kept at 30-50℃; during the reaction, barium hydroxide gradually reacts with hydrogen peroxide, and the active oxygen free radicals produced under the synergistic action of ultrasonic and visible light further strengthen the reaction, so that the system synthesizes barium peroxide with higher purity without a large amount of water mass transfer.

[0024] S5: product drying: the material after reaction is dried by vacuum drying at 60-100℃ to obtain the target product barium peroxide.

[0025] Further, in step S2, the amount of silver / zinc oxide active oxygen initiator added is preferably 1.2-2% by mole of barium hydroxide.

[0026] Further, in step S3, the frequency of the ultrasonic device is preferably 40-60KHz.

[0027] Further, in step S4, the reaction temperature is preferably 30-40℃, the reaction time is 20-60min, preferably 30min.

[0028] Compared with the prior art, the present application has the advantages of: I. The present application introduces part of active oxygen free radicals through ultrasonic-visible light cooperation to promote the further sufficient reaction of barium hydroxide and hydrogen peroxide. The method has high reaction conversion rate, stable product, almost no existence of barium salt and other crystal water impurities, and the content of barium peroxide can reach more than 95%.

[0029] II. The present application has few reaction steps, eliminates the use of a large amount of water as a backing medium, and does not need to be filtered and washed, so that the scale-up production will not cause sewage.

[0030] III. The present application promotes the vibration of the medium through high-frequency ultrasonic waves, so that the intermolecular vibration is strengthened, thereby obtaining barium peroxide with a smaller particle size. DETAILED DESCRIPTION

[0031] Silver / zinc oxide active oxygen initiator preparation: Take 0.4 mol of zinc oxide, add 80 ml of deionized water in a beaker in advance, take 1% of the mass of zinc oxide silver nitrate, add zinc oxide and silver nitrate into the beaker at the same time, mix for 5 min under magnetic stirring adjustment, add a small amount of dilute ammonia water, slowly drop into the system, adjust the pH of the system to 9-11, stir for 10 min, then transfer the material to a polytetrafluoroethylene high-pressure hydrothermal kettle, 150℃, for 8 h, after the material is cooled, filter, wash with deionized water, dry in a vacuum oven at 60℃ for 30 min, and obtain silver / zinc oxide active oxygen initiator for each batch test.

[0032] Example 1:

[0033] Add 1 mol of barium hydroxide to the reactor, adjust the stirring speed to 100 r / min, add 0.012 mol of silver / zinc oxide active oxygen initiator, and stir for 5 min to obtain a reaction precursor; turn on a 25W LED lamp device, and irradiate the visible light to the reactor, at the same time, place the reactor in an ultrasonic wave generating device, start the ultrasonic wave generating device, and set the transmitter frequency to 40KHz; then slowly add atomized hydrogen peroxide, the mass concentration of hydrogen peroxide is 50%; the molar ratio of hydrogen peroxide to barium hydroxide in hydrogen peroxide is 1:1, the temperature is kept at 30-40℃, and the stirring reaction is carried out for 30 min, then the material is placed in a vacuum oven and heated to 80℃, and dried for 30 min to obtain solid barium peroxide. The content of barium peroxide is 97.2%, and the particle size is 86.61μm.

[0034] Example 2:

[0035] Into the reactor, 1 mol of barium hydroxide was added, the stirring speed was adjusted to 120 r / min, 0.018 mol of silver / zinc oxide active oxygen initiator was added, and stirring was performed for 5 min to obtain a reaction precursor; a 25 W LED lamp device was turned on, visible light was aimed at the reactor for irradiation, and the reactor was placed in an ultrasonic generating device, the transmitter frequency was set to 59 KHz, and the ultrasonic generating device was started; then, atomized hydrogen peroxide with a mass concentration of 50% was slowly added; the molar ratio of hydrogen peroxide to barium hydroxide in the hydrogen peroxide was 1:1, the temperature was kept at 30-40 ℃, and stirring was performed for 30 min; then, the material was placed in a vacuum oven and heated to 80 ℃, and dried for 30 min to obtain solid barium peroxide. The content of barium peroxide was 97.1%, and the particle size was 89.13 μm.

[0036] Example 3:

[0037] Into the reactor, 1 mol of barium hydroxide was added, the stirring speed was adjusted to 120 r / min, 0.01 mol of silver / zinc oxide active oxygen initiator was added, and stirring was performed for 5 min to obtain a reaction precursor; a 25 W LED lamp device was turned on, visible light was aimed at the reactor for irradiation, and the reactor was placed in an ultrasonic generating device, the transmitter frequency was set to 59 KHz, and the ultrasonic generating device was started; then, atomized hydrogen peroxide with a mass concentration of 50% was slowly added; the molar ratio of hydrogen peroxide to barium hydroxide in the hydrogen peroxide was 1.1:1, the temperature was kept at 30-40 ℃, and stirring was performed for 30 min; then, the material was placed in a vacuum oven and heated to 80 ℃, and dried for 30 min to obtain solid barium peroxide. The content of barium peroxide was 96.8%, and the particle size was 90.3 μm.

[0038] Example 4:

[0039] Into the reactor, 1 mol of barium hydroxide was added, the stirring speed was adjusted to 120 r / min, 0.02 mol of silver / zinc oxide active oxygen initiator was added, and stirring was performed for 5 min to obtain a reaction precursor; a 25 W LED lamp device was turned on, visible light was aimed at the reactor for irradiation, and the reactor was placed in an ultrasonic generating device, the transmitter frequency was set to 59 KHz, and the ultrasonic generating device was started; then, atomized hydrogen peroxide with a mass concentration of 50% was slowly added; the molar ratio of hydrogen peroxide to barium hydroxide in the hydrogen peroxide was 0.98:1, the temperature was kept at 30-40 ℃, and stirring was performed for 30 min; then, the material was placed in a vacuum oven and heated to 80 ℃, and dried for 30 min to obtain solid barium peroxide. The content of barium peroxide was 95.1%, and the particle size was 88.2 μm.

[0040] Comparative Example 1 without silver / zinc oxide active oxygen initiator: The reactor was added with 1 mol of barium hydroxide, the stirring speed was adjusted to 120 r / min, and stirring was performed for 5 min to obtain a reaction precursor; a 25 W LED lamp device was turned on, visible light was irradiated on the reactor, and the reactor was placed in an ultrasonic generating device; the ultrasonic generating device was started, and the transmitter frequency was set to 40 KHz; then, atomized hydrogen peroxide with a mass concentration of 50% was slowly added; the molar ratio of hydrogen peroxide to barium hydroxide in the hydrogen peroxide was 1:1; the temperature was kept at 30-40 ℃, and stirring was performed for 30 min; then, the material was placed in a vacuum oven and heated to 80 ℃, and dried for 30 min to obtain solid barium peroxide. The content of barium peroxide was 89.3%, and the particle size was 97.69 μm.

[0041] Comparative Example 2 without ultrasonic irradiation: The reactor was added with 1 mol of barium hydroxide, the stirring speed was adjusted to 120 r / min, and 0.012 mol of silver / zinc oxide active oxygen initiator was added to prepare a reaction precursor; a 25 W LED lamp device was turned on, visible light was irradiated on the reactor; then, atomized hydrogen peroxide with a mass concentration of 50% was slowly added; the molar ratio of hydrogen peroxide to barium hydroxide in the hydrogen peroxide was 1:1; the temperature was kept at 30-40 ℃, and stirring was performed for 30 min; then, the material was placed in a vacuum oven and heated to 80 ℃, and dried for 30 min to obtain solid barium peroxide. The content of barium peroxide was 87.73%, and the particle size was 238.2 μm.

[0042] It can be known from Examples 1-4 and Comparative Examples 1-2 that the purity and uniformity of barium peroxide are significantly improved by the synergistic effect of visible light irradiation and ultrasonic waves, so that the purity of barium peroxide is higher than that of Comparative Examples 1-2, and the particle size of barium peroxide is significantly smaller than that of Comparative Examples 1-2.

[0043] Comparative Example 3 in which the silver / zinc oxide active oxygen initiator is replaced with zinc hydroxide: The reactor was added with 1 mol of barium hydroxide, the stirring speed was adjusted to 120 r / min, and 0.012 mol of silver / zinc oxide active oxygen initiator was added to prepare a reaction precursor; a 25 W LED lamp device was turned on, visible light was irradiated on the reactor, and the reactor was placed in an ultrasonic generating device; the ultrasonic generating device was started, and the transmitter frequency was set to 40 KHz; then, atomized hydrogen peroxide with a mass concentration of 50% was slowly added; the molar ratio of hydrogen peroxide to barium hydroxide in the hydrogen peroxide was 1:1; the temperature was kept at 30-40 ℃, and stirring was performed for 30 min; then, the material was placed in a vacuum oven and heated to 80 ℃, and dried for 30 min to obtain solid barium peroxide. The content of barium peroxide was 87.73%, and the particle size was 238.2 μm.

[0044] From Examples 1-4, Comparative Example 1 and Comparative Example 3, it can be seen that the surface silver / zinc oxide active oxygen initiator is indispensable and irreplaceable as an excellent free radical initiator in the present application.

[0045] Comparative Example 4 (prior art wet process): Step one: add 4 times deionized water to the reaction vessel as a primer medium, 100 r / min stirring, then add 1 mol of barium hydroxide to the reaction kettle.

[0046] Step two: prepare 50% mass concentration of hydrogen peroxide solution in advance, slowly add it to the reaction kettle, control the reaction temperature at 30-40℃, and react for 30 min. The molar ratio of hydrogen peroxide to barium hydroxide in the hydrogen peroxide solution is 1:1. Then use a vacuum pump to filter and collect the solid for washing to obtain wet barium peroxide, which is dried by vacuum drying for 30 min to obtain solid barium peroxide. The content of barium peroxide is 84% and the particle size is 253.6 μm.

[0047] From Examples 1-4 and Comparative Example 4, it can be seen that the present application significantly improves the purity, particle size control and reaction efficiency of barium peroxide through the synergistic effect of visible light irradiation and ultrasonic waves, which has a significant advantage over the wet preparation process of Comparative Example 4.

Claims

1. A method for preparing barium peroxide using a combined ultrasonic-visible light dry process, characterized in that: The preparation method is as follows: Barium hydroxide solid is added to the reactor, followed by modified zinc oxide carrier. After stirring for a certain period of time, the visible light and ultrasonic generators are turned on, and stirring continues. At the same time, atomized hydrogen peroxide is slowly added. After reacting for a certain period of time, the mixture is dried to obtain barium peroxide solid.

2. The method for preparing barium peroxide by ultrasound-visible light synergistic dry process according to claim 1, characterized in that: The visible light source is an LED lamp with a power of 20-100 W.

3. The method for preparing barium peroxide by ultrasound-visible light synergistic dry process according to claim 1, characterized in that: The frequency of the ultrasound is 20-120KHz.

4. The method for preparing barium peroxide by ultrasound-visible light synergistic dry process according to claim 1, characterized in that: The amount of the modified zinc oxide carrier added is 0.2-2% of the molar amount of barium hydroxide.

5. The method for preparing barium peroxide by ultrasound-visible light synergistic dry process according to claim 1, characterized in that: The mass concentration of hydrogen peroxide is 30-70%, and the molar ratio of pure hydrogen peroxide to barium hydroxide in hydrogen peroxide is 0.98-1.1:

1.

6. The method for preparing barium peroxide by ultrasound-visible light synergistic dry process according to claim 1, characterized in that: The mixing and stirring time for barium hydroxide and modified zinc oxide carrier is 5 min; the reaction temperature is 30-50℃ and the reaction time is 20-60 min; the drying temperature is 60-100℃ and the drying time is 20-60 min.

7. The method for preparing barium peroxide by ultrasound-visible light synergistic dry process according to claim 1, characterized in that: The modified zinc oxide carrier is a silver / zinc oxide reactive oxygen initiator.

8. The method for preparing barium peroxide by ultrasound-visible light synergistic dry process according to claim 7, characterized in that: The preparation method of the silver / zinc oxide reactive oxygen initiator is as follows: zinc oxide and silver nitrate are added together to deionized water, magnetically stirred, and ammonia is added to adjust the pH to 9-11. Stirring is continued for a certain time to obtain the precursor. Then, it is transferred to a tetrafluoroethylene high-pressure hydrothermal reactor, heated and kept at the temperature for a certain time. After cooling to room temperature, it is filtered, washed and dried to obtain the silver / zinc oxide reactive oxygen initiator.

9. The method for preparing barium peroxide by ultrasound-visible light synergistic dry process according to claim 8, characterized in that: The amount of silver nitrate added is 0.8-1.2% of the mass fraction of zinc oxide.

10. The method for preparing barium peroxide by ultrasound-visible light synergistic dry process according to claim 8, characterized in that: The magnetic stirring temperature is 20-30℃, and the stirring time is 5-10 min. After adding ammonia, the stirring time is 5-10 min. The pressure vessel reaction holding temperature is 140-180℃, and the reaction time is 8 h. The drying temperature is 60-80℃, and the drying time is 10-30 min.