WO2025067224A1 - Method for preparing permanganate and apparatus thereof - Google Patents

Abstract

Disclosed is a method for preparing a permanganate, comprising the following steps: placing a solution mixture containing a manganate and a strong alkaline substance in a gas-liquid mixing ozone reactor for an oxidation reaction with ozone to generate a permanganate; and, upon the amount of the permanganate generated in the mixture reaching a concentration and/or weight set by the process, considering the reaction to be completed and collecting a product containing the permanganate. The method solves the problems of high energy consumption and potential safety hazards in the prior art and can be used for production on a small scale. Further disclosed is an apparatus for preparing a permanganate.

Description

A method and device for preparing permanganate Technical Field

The invention relates to a method for preparing a compound, and in particular to a method for preparing permanganate and a device thereof.

Background Art

Permanganate is a strong oxidant with a wide range of applications and is relatively expensive. The current industrial production process of permanganate is generally: first use manganese dioxide and sodium hydroxide/potassium hydroxide to obtain manganate through a solid phase roasting method (roasting temperature reaches 250-300°C), and then obtain permanganate through a disproportionation reaction or obtain permanganate through an electrolytic method. Among them, the disproportionation reaction is to disproportionate manganate into permanganate and manganese dioxide under a specific solution environment, that is, only half of the manganese can be converted into permanganate. Therefore, the production of permanganate by the disproportionation reaction method requires the load of roasting to produce manganate to double, the energy consumption is large, and the efficiency is low. The electrolytic oxidation method for producing permanganate has high requirements for the diaphragm of the electrolytic cell and high power consumption, and its production cost and efficiency are easily affected by the current density and electrolyte temperature. There are also safety hazards caused by the precipitation of flammable and explosive hydrogen during the electrolysis process. The high temperature operating conditions and high energy consumption of the above-mentioned disproportionation reaction method, and the difficulty of process control and high power consumption of the electrolysis method make the above-mentioned two existing technologies for preparing permanganate more suitable for large-scale production in a specified site, but not suitable for small-scale application.

Summary of the invention

The first invention object of the present invention is to provide a method for preparing permanganate, which improves the process characteristics of the gas-liquid oxidation reaction in the product production process in the direction of safety and efficiency, solves the high energy consumption and potential safety hazards of the prior art, and can be produced on a small scale. The second invention object of the present invention is to provide a production device for the process improvement of the product, and provide a permanganate preparation device to achieve the first object of the present invention while meeting the conditions for the production process improvement.

The first object of the present invention is achieved through the following technical solutions.

A method for preparing permanganate comprises the following steps:

Placing a solution mixture containing manganate and a strong alkaline substance in a gas-liquid mixed ozone reactor to undergo an oxidation reaction with ozone to generate permanganate;

When the amount of permanganate generated in the mixture reaches the concentration and/or weight set in the process, the reaction is considered to be completed, and a solution product containing permanganate, or a solid-liquid mixture product containing permanganate solid is collected.

The manganate described in the present invention is sodium manganate and/or potassium manganate. The permanganate prepared in the present invention is permanganate Sodium permanganate and/or potassium permanganate.

The strong alkaline substance described in the present invention is an inorganic base, specifically one or more selected from sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, and can be used in a solid form or in the form of an aqueous solution. Preferably, the strong alkaline substance contains sodium hydroxide and/or potassium hydroxide. The strong alkaline substance is used to provide an alkaline environment for the reaction mixture to stabilize the manganate so that it can smoothly undergo an oxidation reaction. Preferably, the concentration of the strong alkaline substance in the solution mixture is not less than 0.8 mol/L based on the cations it provides.

The chemical reactions occurring in the gas-liquid mixed ozone reactor are shown below.

The chemical reaction formula for the oxidation reaction to produce permanganate is as follows:

6Na ₂ MnO ₄ +O ₃ +3H ₂ O→6NaMnO ₄ +6NaOH;

6K ₂ MnO ₄ +O ₃ +3H ₂ O→6KMnO ₄ +6KOH.

As a specific embodiment of the present invention, the solution mixture further includes manganese dioxide or permanganate. When the solution mixture further includes manganese dioxide, it becomes a solid-liquid mixture.

When the mixture contains manganese dioxide, permanganate undergoes a redox reaction with it to form manganate. The specific chemical reaction formula is as follows:
2MnO ₄ ^- +MnO ₂ +4OH ^- →3MnO ₄ ^2- +2H ₂ O;
2MnO ₄ ^- +MnO ₂ +2CO ₃ ^2- →3MnO ₄ ^2- +2CO ₂ ↑;
2MnO ₄ ^- +MnO ₂ +4HCO ₃ ^- →3MnO ₄ ^2- +2H ₂ O+4CO ₂ ↑.

The manganate generated above can be further oxidized with ozone to produce permanganate.

The present invention has no restrictions on the method of obtaining manganate, and manganate can be directly used as a raw material, or manganate obtained by the neutralization reaction of manganese dioxide and permanganate can be used as a raw material. When the manganate is obtained by the neutralization reaction of manganese dioxide and permanganate, the permanganate involved in the neutralization reaction is an externally added permanganate and/or a permanganate obtained by an oxidation reaction of manganate and ozone. This scheme can avoid the high temperature reaction conditions of roasting to prepare manganate in the prior art, and greatly reduce the energy consumption required for the reaction.

As a preferred embodiment of the present invention, permanganate generated by oxidation reaction of manganate with ozone and manganese dioxide are used for neutralization reaction to prepare manganate as the raw material of the present invention. When permanganate generated by oxidation reaction of manganate with ozone is used for neutralization reaction with manganese dioxide to prepare manganate, part of the manganese element in the obtained manganate comes from manganese dioxide, that is, only part of the obtained permanganate is needed to prepare new manganate.

As can be seen from the above chemical reaction formula, the neutralization reaction of permanganate and manganese dioxide requires the participation of a strongly alkaline substance. Therefore, permanganate, manganese dioxide and a strongly alkaline substance can be mixed and reacted to obtain a solution mixture containing manganate and a strongly alkaline substance according to the present invention, or a mixture further containing manganese dioxide or permanganate. If a mixture containing manganate, a strongly alkaline substance and manganese dioxide is subjected to an oxidation reaction with ozone in a gas-liquid mixed ozone reactor, the generated permanganate can be used to react with the manganese dioxide and the strongly alkaline substance in the mixture to generate a new manganate, and continue to be oxidized to a new permanganate; this process only requires a small amount of permanganate as a start-up accelerator, and even does not require the addition of permanganate. When carbonate and/or bicarbonate are used alone as a strongly alkaline substance to participate in the neutralization reaction of permanganate and manganese dioxide, its reaction speed is slow, and carbon dioxide gas is precipitated. Therefore, the strong alkaline substance preferably contains sodium hydroxide and/or potassium hydroxide, and when the neutralization reaction rate of permanganate and manganese dioxide is lower than the requirement of the process setting, the concentration of sodium hydroxide and/or potassium hydroxide in the strong alkaline substance is increased accordingly.

The gas-liquid mixing ozone reactor is a gas-liquid mixer, specifically a bubbling gas-liquid mixer and/or a vacuum jet gas-liquid mixer.

The temperature range of the oxidation reaction is 3-75° C. Since the entire oxidation process is a gas-liquid mixture reacting with ozone, in order to ensure the fluidity of the solution and to use temperature to promote the oxidation reaction while avoiding the decomposition of the generated permanganate due to excessively high temperature, the temperature of the oxidation reaction is preferably 8-60° C. More preferably, the temperature of the oxidation reaction is 20-45° C.

The ozone described in the present invention preferably comes from an ozone generator. The oxygen source of the ozone generator can be selected from commercial oxygen, commercial liquid oxygen, oxygen produced by chemical methods, oxygen produced by electrolysis, or a combination of more than one. Preferably, hydrogen peroxide and manganese dioxide are used to chemically react to produce oxygen, and/or water electrolysis oxygen production equipment is used to produce oxygen, which has a simple process and a low cost for producing oxygen.

The present invention can also be improved as follows: in order to make the reaction liquid and ozone contact and react better in the oxidation reaction, the reaction liquid in the gas-liquid mixed ozone reactor is physically stirred, and/or an ultrasonic generator is used to disperse and refine the ozone bubbles, so as to better participate in the oxidation reaction with manganate.

The present invention can be improved as follows: during the oxidation reaction, iridium oxide IrOx is placed in a gas-liquid mixed ozone reactor in a reaction mixture as a reaction catalyst. The reaction catalyst can be selected from pure iridium oxide powder and/or a metal substrate coated with iridium oxide on the surface, wherein the metal substrate is an amorphous strip and/or granular and/or mesh sheet. Preferably, a titanium metal substrate coated with iridium oxide on the surface is used as the reaction catalyst. Using a metal substrate coated with iridium oxide on the surface as a reaction catalyst can avoid After the oxidation-free reaction, the solid-liquid separation process of the product solution and the reaction catalyst is carried out. In order to ensure that the iridium oxide coating on the metal substrate can evenly cover the metal substrate and achieve the expected protection effect, the use time is set according to the process production conditions and the iridium oxide coating on the metal substrate is re-coated in time to ensure the safety and effectiveness of the coating.

The present invention can also be improved as follows: when oxygen produced by electrolysis is used as the oxygen source of the ozone generator, the oxygen produced by electrolysis is washed with water to remove acidic or alkaline impurities from the electrolyte contained in the oxygen, and then the oxygen after washing is freeze-dried; the oxygen after the above treatment is supplied to the ozone generator for use, which not only increases safety but also improves ozone production efficiency.

The present invention can also be improved as follows: in the gas-liquid mixed ozone reactor, ozone is input from the bottom or the middle and lower part thereof, and a liquid extraction pipe is provided at the bottom or the middle and lower part of the gas-liquid mixed ozone reactor, and the ozone bubbles are used to float upward from the bottom to form a reverse motion with the reaction liquid to increase the chance of contact reaction. Preferably, after adding the reverse motion condition of the above-mentioned reactants, at least one through-hole partition is placed in the gas-liquid mixed ozone reactor at and/or below the liquid level of the reaction liquid to reduce the direct escape of ozone in the reaction liquid and improve the product yield.

The present invention can also be improved as follows: in the processes using permanganate in various fields, manganese dioxide is recovered from the manganese-containing waste solution or solid-liquid mixture produced by these processes as the raw material for preparation of the present invention, which can reduce environmental pollution and save production costs. In particular, in the processes using permanganate in various fields, the permanganate prepared by the present invention is used for oxidation reaction, and manganese dioxide is recovered from the waste liquid produced after the reaction, and then it is used as a raw material to re-prepare permanganate by the method of the present invention for use, so as to realize the recycling of manganese and greatly reduce the cost of use. Manganese dioxide is specifically recovered in the following manner: 1) manganese dioxide generated after using permanganate is collected as the raw material for preparation of the present invention for recycling; 2) for the divalent manganese salt generated after using permanganate, the pH value of the manganese-containing waste liquid is increased to make it alkaline, neutral or even weakly acidic conditions, and then an oxidant is added, and the divalent manganese is converted into manganese dioxide and then collected as the raw material for preparation of the present invention for recycling, and the oxidant is selected from persulfate, chlorine, hypochlorite, sodium chlorate, hydrogen peroxide, one or more combinations thereof.

The present invention can also be improved as follows: to solve the ozone tail gas pollution, an acidic ferrous salt solution is used to absorb the ozone tail gas discharged from the gas-liquid mixed ozone reactor, and is used to prepare ferric sulfate solution and/or ferric chloride solution products.

The present invention can also be improved as follows: since the solubility of sodium manganate is greater than that of potassium manganate, and the solubility of sodium permanganate is greater than that of potassium permanganate; in order to prepare solid permanganate, a gas-liquid mixed ozone reactor containing a relatively high concentration of The mixture of potassium permanganate and potassium permanganate reacts with ozone, so that the potassium permanganate generated by the reaction is easily crystallized from the reaction solution to form a potassium permanganate solid product. In this improved scheme, the suitable potassium manganate concentration varies depending on the concentration of the strong alkaline substance in the mixture. When no potassium permanganate crystals are precipitated during the reaction or the amount of precipitation is lower than the requirement set by the process, the potassium manganate concentration in the mixture participating in the reaction is increased.

The second object of the present invention is achieved through the following scheme.

A permanganate preparation device is characterized by comprising an ozone generator, an oxygen source device connected thereto, and a gas-liquid mixed ozone reactor.

The ozone generator is a commercially available product.

The oxygen source equipment is one or more of an oxygen cylinder, a liquid oxygen cylinder, a chemical oxygen production reactor, and an oxygen production electrolyzer.

The gas-liquid mixed ozone reactor is specifically a bubbling gas-liquid mixer and/or a jet gas-liquid mixer. Specifically, the ozone output port of the ozone generator is connected to the gas input port of the gas-liquid mixed ozone reactor through an air pipe. The gas-liquid mixed ozone reactor is made of corrosion-resistant materials.

The present invention can be improved as follows: when a bubbling gas-liquid mixer is used as a gas-liquid mixed ozone reactor, in order to slow down the ozone in the reaction liquid from escaping directly upward out of the reaction liquid, as shown in FIG5 , an upper through-hole baffle is provided in the gas-liquid mixed ozone reactor at or below the liquid surface to prevent ozone bubbles from escaping directly upward, thereby increasing the reaction opportunity and improving the yield.

The present invention can also be improved as follows: a metal substrate coated with iridium oxide is placed in the gas-liquid mixed ozone reactor as a reaction catalyst, wherein the metal substrate is in the form of amorphous strips and/or particles and/or grids.

The present invention can be improved as follows: a cold and hot temperature exchanger is added to make the working temperature of the reaction liquid meet the process requirements. The cold and hot temperature exchanger is installed on the gas-liquid mixed ozone reactor and/or the temporary storage tank and/or the chemical reaction tank.

The present invention can also be improved as follows: a chemical oxygen production reactor and/or an oxygen production electrolyzer is selected to produce oxygen, and an oxygen pressure pump is arranged on the pipeline between the oxygen production reactor and the ozone generator to supply oxygen to the ozone generator after pressurizing the oxygen. The oxygen produced by the oxygen production electrolyzer is preferably washed with water and dehydrated and dried at low temperature before being supplied to the oxygen pressure pump, and then the oxygen pressure pump supplies oxygen to the ozone generator, so as to improve the safety of the ozone production equipment and the ozone yield.

The present invention can also be improved as follows: an oxygen water washing tank is added to wash the oxygen collected from the oxygen electrolyzer. Cleaning is performed to remove acid and alkali impurities. Specifically, an air pipe is connected between the anode tank area of the oxygen electrolytic cell and the oxygen water washing tank.

The present invention can also be improved as follows: a freeze dryer is added to dry the oxygen by condensing the water in the oxygen at low temperature, so as to improve the yield of the ozone generator. Specifically, the oxygen water washing tank is connected to the freeze dryer through an air pipe, and the freeze dryer is connected to the oxygen pressure pump through an air pipe.

The present invention can also be improved as follows: a solid-liquid separator is added to separate the solid-liquid mixture into solid and liquid. The solid-liquid separator can be connected to the gas-liquid mixed ozone reactor and/or the temporary storage tank by a pipeline.

The present invention can also be improved as follows: an agitator is added to the gas-liquid mixing ozone reactor and/or the temporary storage tank and/or the chemical reaction tank to make the concentration and temperature of the substance in the container uniform. The agitator is selected from one or more combinations of an impeller agitator, a liquid flow agitator and an ultrasonic generator according to the structure. Preferably, when a bubbling gas-liquid mixer is used as a gas-liquid mixing ozone reactor, a pump and a pipeline are set at its bottom as a liquid flow agitator to suck the reaction liquid so that the reaction liquid flows slowly downward, thereby moving in the opposite direction with the upwardly floating ozone bubbles to increase the chance of contact reaction between ozone and manganate, thereby improving the product yield. Preferably, when an ultrasonic generator is used, since the reaction liquid of the present invention is an alkaline highly corrosive solution containing permanganate and/or manganate, an external liquid box is added to the container to which ultrasonic waves need to be applied, and the ultrasonic generator is installed inside or outside the external liquid box; as shown in the ultrasonic generator 40 in Figure 5, the external liquid box contains liquid and is close to the container to which ultrasonic waves need to be applied.

The present invention can also be improved as follows: a temporary storage tank is added to temporarily store solid materials and solutions. The temporary storage tank is connected to the gas-liquid mixed ozone generator and/or the solid-liquid separator through a pipeline.

The present invention can also be improved as follows: a chemical reaction tank is added to prepare raw materials for the production of manganate solution and to recover manganese compounds in waste liquid for reaction. The chemical reaction tank is connected to the gas-liquid mixing ozone generator and/or the solid-liquid separator and/or the temporary storage tank through a pipeline.

The present invention can also be improved as follows: a buffer tank is added to solve the problem of high and low level flow of liquid between tanks. The buffer tank is connected to the gas-liquid mixing ozone generator and/or solid-liquid separator and/or temporary storage tank and/or chemical reaction tank through a pipeline or a pipeline and a pump.

The present invention can also be improved as follows: an exhaust gas processor is added to treat the exhaust gas discharged from each tank in the device safely and environmentally friendly. The exhaust gas processor is specifically a vacuum ejector or spray tower in the gas-liquid mixer. Specifically, it is connected to the exhaust gas outlet of each tank in the device through an air pipe. The absorption treatment of ozone exhaust gas in the exhaust gas processor is particularly important. Acidic ferrous salt solution is used as an absorption liquid for ozone exhaust gas to reduce the impact on the environment. pollute.

The present invention can also be improved as follows: a program logic controller (PLC) and a sensor are added to enable the device to realize automated process control and achieve safe and efficient production. The sensor is at least one of a pH meter, an oxidation-reduction potentiometer (ORP meter), a hydrometer, a photoelectric colorimeter, a liquid level meter, and a thermometer. The signal input end of the program logic controller is connected to the signal output end of the sensor, and the signal output end of the program logic controller is connected to the signal input end of at least one device in the device, such as a pump, a valve, an ozone generator, a hot and cold temperature exchanger, a stirrer, and an oxygen-producing electrolyzer.

The present invention can also be improved as follows: when more than one gas-liquid mixed ozone reactor is used, two or more gas-liquid mixed ozone generators are connected in series through a gas pipeline according to the flow direction of ozone to form a two-stage or multi-stage series gas-liquid mixed ozone reactor, so that ozone can be fully utilized in the reaction process.

Compared with the prior art, the present invention has the following beneficial effects.

1. The method of the present invention solves the problems of low efficiency and high energy consumption of the disproportionation reaction method in the prior art process for preparing permanganate, and avoids the problems of high power consumption, production cost and easily affected efficiency of the electrolysis method in the prior art process for preparing permanganate, and also avoids the high temperature operating conditions required by the prior art method, and is also suitable for small-scale application.

2. The present invention adopts gas-liquid oxidation reaction to prepare permanganate, preferably catalytic oxidation reaction, to improve production efficiency, make the production process safer and energy-saving.

3. The process for preparing permanganate of the present invention does not generate any new pollutants, and can also recycle the manganese dioxide produced after the use of permanganate, thereby reducing pollution to the environment and greatly reducing the use cost of permanganate.

4. The device for preparing permanganate of the present invention is simple, requires little investment, has low maintenance cost and high economic benefit.

5. The device for preparing permanganate of the present invention can be set up in the factory area where the permanganate is used. The low-priced manganese produced after the waste liquid treatment is recovered as the manganese dioxide raw material required by the present invention, thereby achieving the process requirements of environmental protection, energy saving and recycling.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of a permanganate preparation device according to Example 1.

FIG. 2 is a schematic structural diagram of a permanganate preparation device according to Example 2.

FIG3 is a schematic structural diagram of a permanganate preparation device according to Example 3.

Fig. 4 is a schematic diagram of the structure of the permanganate preparation device of Example 4; Fig. 4-1, Fig. 4-2 and Fig. 4-3 are partial views of Fig. 4 respectively, and the three constitute a complete schematic diagram of the structure of the permanganate preparation device of Example 4.

FIG5 is a schematic diagram of the structure of the gas-liquid mixed ozone reactor of the present invention, wherein the gas-liquid mixed ozone reactor is a bubbling gas-liquid mixer.

Figure numerals: 1-ozone generator, 2-oxygen source equipment, 3-gas-liquid mixed ozone reactor, 4-oxygen electrolyzer, 5-electrolysis power supply, 6-cold and hot temperature exchanger, 7-oxygen water washing tank, 8-exhaust hydrogen, 9-freeze dryer, 10-solid-liquid separator, 11-temporary storage tank, 12-buffer tank, 13-agitator, 14-exhaust gas processor, 15-programmed logic controller, 16-sensor, 17-valve, 18-pump, 19-bubbling gas-liquid mixer, 20-vacuum jet gas-liquid mixer, 21-manganese acid Salt solution, 22-manganese dioxide, 23-permanganate solution, 24-permanganate solid, 25-sodium hydroxide solution, 26-potassium hydroxide solution, 27-clean water, 28-ozone, 29-oxygen, 30-hydrogen peroxide, 31-oxygen booster pump, 32-chemical reaction tank, 33-chemical oxygen production reactor, 34-reaction catalyst, 35-acidic ferrous salt solution, 36-ferric chloride solution, 37-ferric sulfate solution, 38-organic waste liquid to be treated, 39-liquid spray pipe, 40-ultrasonic generator, 41-through-hole partition.

In the drawings and the following embodiments, multiple components of the same component type in the device are represented by "reference numerals". For example, oxygen source device 2-1 means one of the oxygen source devices, and oxygen source device 2-2 means the second of the oxygen source devices.

DETAILED DESCRIPTION

The present invention is further described below by means of specific examples.

The gas-liquid mixed ozone reactor, chemical oxygen reactor, electrolyzer, temporary storage tank, chemical reaction tank, and tail gas processor used in the following embodiments are all products manufactured by Foshan Yegao Environmental Protection Equipment Manufacturing Co., Ltd., Guangdong Province, China. Ozone generators, commercial oxygen, solid-liquid separators, sensors, program logic controllers, oxygen booster pumps, pumps and valves, and chemical raw materials are all commercially available products. In addition to the above, those skilled in the art can also select other products with similar performance to the above products listed in the present invention according to conventional selection, and all of them can achieve the purpose of the present invention.

As shown in FIG5 , it is a schematic diagram of the structure of a gas-liquid mixed ozone reactor of the present invention. The gas-liquid mixed ozone reactor 3 is a bubbling gas-liquid mixed ozone generator; a pipe with a valve and a pump is arranged at the bottom thereof for sucking the reaction liquid so that the reaction liquid flows slowly downward, so that the ozone bubbles float upward while the reaction liquid flows downward in the reverse direction to increase the reaction opportunity of ozone and manganate solution and improve the permanganate yield. At the same time, it also acts as a liquid flow pump pipe agitator to return the reaction liquid to the gas-liquid mixed ozone reactor through the liquid spray pipe 39. In the gas-liquid mixed ozone reactor, the reaction liquid is refluxed to the gas-liquid mixed ozone reactor through the liquid spray pipe 39. The ozone reactor 3 is also provided with through-hole partitions 41-1 and 41-2 to reduce the ozone bubbles from escaping directly upward from the reaction liquid. Three sensors 16 are installed in the gas-liquid mixed ozone generator 3, and a reaction catalyst is placed on the through-hole partition 41-2. The gas-liquid mixed ozone generator 3 is also provided with a cold and hot temperature exchanger 6, ultrasonic generators 40-1 and 40-2, the ultrasonic generator 40-1 is installed outside the external liquid box of the gas-liquid mixed ozone generator 3, and the ultrasonic generator 40-2 is placed in the external liquid box of the gas-liquid mixed ozone generator 3, and the external liquid box is loaded with clean water.

Example 1

As shown in FIG1 , it is the permanganate preparation device of Example 1, and the device includes an ozone generator 1, two oxygen source devices 2, a gas-liquid mixed ozone reactor 3, a cold and hot temperature exchanger 6, an agitator 13, a valve and a pump. Among them, the oxygen source devices 2-1 and 2-2 are commercial liquid oxygen bottles and oxygen bottles, respectively. The gas-liquid mixed ozone generator 3 adopts a bubbling gas-liquid mixed ozone generator, which is an open reactor (40 liters) and is equipped with a bubbling gas-liquid mixer; and a cold and hot temperature exchanger 6 and an agitator 13 are installed in the reactor, and the agitator 13 is an impeller agitator. A thermometer 16 is also provided in the gas-liquid mixed ozone generator 3 for detecting the temperature of the reaction liquid.

The oxygen outlet pipe of the oxygen source device 2-1 and the oxygen outlet pipe of the oxygen source device 2-2 are respectively connected to the ozone generator 1 through air pipes to supply oxygen for ozone reaction. In addition, the ozone output port of the ozone generator 1 is connected to the air pipe port of the bubbling gas-liquid mixer of the gas-liquid mixing ozone generator 3 through an air pipe.

The steps of preparing the permanganate mixed solution product in this embodiment are as follows:

1. Adding the starting mixture to the gas-liquid mixed ozone reactor 3;

2. Open the liquid oxygen bottle and the oxygen bottle to supply oxygen to the ozone generator; open the ozone generator 1 to produce ozone, and transport the ozone to the gas-liquid mixed ozone reactor 3, and the ozone contacts the reaction liquid to carry out oxidation reaction; open the agitator 13 and the hot and cold temperature exchanger 6, and control the temperature of the reaction liquid at 75°C during the reaction process;

3. After 28 hours of reaction, a mixed solution product containing sodium permanganate and potassium permanganate is obtained. After sampling and testing, the permanganate concentration reaches the process index, the oxygen cylinder and liquid oxygen cylinder are closed, and the ozone generator is shut down;

4. Open valve 17 and start pump 18 to extract the solution product in gas-liquid mixed ozone reactor 3.

The process parameters of the reaction solution of this embodiment 1 are listed in Table 1.

Example 2

As shown in FIG. 2 , the permanganate preparation device of Example 2 includes an ozone generator 1, Oxygen source equipment 2, gas-liquid mixed ozone reactor 3, hot and cold temperature exchanger 6, solid-liquid separator 10, impeller stirrer 13, sensors 16-1, 16-2 and 16-3, oxygen booster pump 31, ultrasonic generator 40, multiple valves and pumps.

The oxygen source device 2 is a chemical oxygen reactor 33, and the raw materials for oxygen production reaction in the chemical oxygen reactor 33 are hydrogen peroxide and manganese dioxide catalyst. A stirrer 13 and a sensor 16-1 are installed in the chemical oxygen reactor 33, the stirrer 13 is an impeller stirrer, and the sensor 16-1 is a liquid level meter.

The gas-liquid mixed ozone reactor 3 is a vacuum jet gas-liquid mixed ozone reactor, which is a closed reactor (40 liters) and is equipped with a vacuum jet gas-liquid mixer 20. Sensors 16-2 and 16-3 are installed therein, which are a thermometer and a photoelectric colorimeter respectively. A hot and cold temperature exchanger 6 and an ultrasonic generator 40 are also arranged on the gas-liquid mixed ozone reactor 3.

The solid-liquid separator 10 is connected to the reaction liquid discharge pipeline of the gas-liquid mixed ozone reactor 3 and is used for filtering and collecting the iridium oxide powder solid in the product solution.

The oxygen output port of the chemical oxygen production reactor 33 is connected to the oxygen booster pump 31 through an air pipe, and the air outlet of the oxygen booster pump is connected to the air inlet of the ozone generator 1 through an air pipe, and the air outlet of the ozone generator 1 is connected to the air inlet of the vacuum jet gas-liquid mixer 20.

This embodiment uses iridium oxide powder as a reaction catalyst in the oxidation reaction process.

The steps of preparing the sodium permanganate solution product in this embodiment are as follows:

1. Add the starting mixture to participate in the reaction and an appropriate amount of iridium oxide powder into the gas-liquid mixed ozone reactor 3;

2. Add hydrogen peroxide and manganese dioxide into the chemical oxygen reactor 33 to react and generate oxygen, and supply the generated oxygen to the ozone generator through the oxygen booster pump; start the oxygen booster pump, start the ozone generator 1 to prepare ozone, and start the pump 18-1 to introduce the ozone into the gas-liquid mixed ozone reactor 3 to mix and react with the reaction liquid; start the hot and cold temperature exchanger 6, adjust the temperature of the reaction liquid to 45°C, and start the ultrasonic generator 40 to stir the reaction liquid;

3. After 25 hours of oxidation reaction, if the color of the reaction liquid reaches the set value of the photoelectric colorimeter, the reaction is considered complete, and the chemical oxygen reactor 33, the oxidation booster pump 31, the ozone generator 1, the cold and hot temperature exchanger 6 and the pump 18-1 are shut down;

4. Open valve 17-2 and start pump 18-2 to collect the solution product containing permanganate. During the collection process, use a filter to collect the iridium oxide powder in the product solution for next use. Shut down the device.

The process parameters of the reaction solution of this embodiment 2 are listed in Table 1.

Example 3

As shown in FIG3 , the permanganate preparation device of Example 3 includes an ozone generator 1, an oxygen source device 2, a gas-liquid mixed ozone reactor 3, two cold and hot temperature exchangers 6-1 and 6-2, a solid-liquid separator 10, four temporary storage tanks 11, a stirrer 13, five sensors 16, an oxygen booster pump 31, an exhaust gas processor 14, multiple valves and pumps. Among them, sensor 16-1 is a thermometer, 16-2 is an ORP meter, 16-3 is a photoelectric colorimeter, 16-4 is a liquid level meter, and 16-5 is an ORP meter. The solid-liquid separator 10 is a filter press.

A sensor 16 - 1 , a cold and hot temperature exchanger 6 - 1 and a stirrer 13 are installed in the chemical oxygen production reactor 33 . The stirrer 13 is an impeller stirrer.

The gas-liquid mixing ozone generator 3 adopts a vacuum ejector structure, which is a closed reactor (40 liters) and is provided with a vacuum ejector gas-liquid mixer 20 , as well as a hot and cold temperature exchanger 6 , and sensors 16 - 2 and 16 - 3 installed in the reactor 3 .

Sensors 16 - 4 and 16 - 5 are installed in the exhaust gas processor 14 , and the sensor 16 - 5 is used to control the addition of external acidic ferric chloride ferrous solution 35 .

In the device of this embodiment, the temporary storage tank 11-1 is connected to the chemical oxygen reactor 33 through a pipeline and a pump; the chemical oxygen reactor 33 is connected to the oxygen booster pump 31 and the ozone generator 1 through an air pipe; the ozone generator 1 is connected to the vacuum jet gas-liquid mixer 20 of the gas-liquid mixing ozone generator 3 through a gas pipeline; the gas-liquid mixing ozone reactor 3 is connected to the solid-liquid separator 10 through a pipeline and a pump; the solid-liquid separator 10 is connected to the temporary storage tank 11-3 through a buffer tank 12, a pump, and a pipeline; the exhaust gas processor 14 is connected to the exhaust gas escape port of each tank through an air pipe; the exhaust gas processor 14 is connected to the temporary storage tank 11-4 through a pump pipeline.

The reaction catalyst used in this embodiment is titanium metal strips with iridium oxide coated on the surface.

The steps of preparing the sodium permanganate solution product in this embodiment are as follows:

1. Put hydrogen peroxide into the temporary storage tank 11-1, put manganese dioxide into the chemical oxygen reactor 33, put the starting mixture involved in the reaction into the gas-liquid mixed ozone reactor 3, and put the acidic ferrous chloride solution 35 into the tail gas processor 14;

2. Start the agitator 13, start the metering pump 18-1 to add hydrogen peroxide, start the oxygen booster pump, start the ozone generator 1; start the pump 18-2 to cause an oxidation reaction in the gas-liquid mixed ozone reactor 3; start the tail Gas processor 14;

3. During the reaction process, the temperature of the reaction liquid is controlled at 20°C, and the exhaust gas discharged from the gas-liquid mixed ozone reactor 3 is led to the exhaust gas processor 14 for environmental protection treatment; after 16 hours of oxidation reaction, the reaction liquid reaches the set value of the photoelectric colorimeter 16-3, the chemical oxygen reactor 33, the oxidation booster pump 31, the ozone generator 1, and the pump 18-2 are shut down, and the valves 17-4 and 17-5 are opened, and the pumps 18-3 and 18-4 are turned on, and the mixture in the gas-liquid mixed ozone reactor 3 is filtered, and the solution product 23 is taken out and drained to the temporary storage tank 11-3 for temporary storage;

4. The filter residue manganese dioxide 22-2 from the filter press is used for the next round of permanganate preparation and is added to the gas-liquid mixed ozone reactor 3 as the reaction raw material manganese dioxide 22-1.

The process parameters of the reaction solution of this embodiment 3 are listed in Table 1.

Example 4

As shown in FIG4 , the permanganate preparation device of Example 4 includes an ozone generator 1, an oxygen source device 2, two gas-liquid mixed ozone reactors 3, two cold and hot temperature exchangers, an oxygen water washing tank 7, an external hydrogen exhaust pipe 8, a freeze dryer 9, two solid-liquid separators 10, four temporary storage tanks 11, three liquid flow buffer tanks 12, three liquid flow pump pipe agitators 13, an exhaust gas processor 14, a program logic controller 15, fourteen sensors 16, two oxygen booster pumps 31, three chemical reaction tanks 32, reaction catalysts 34-1 and 34-2, two ultrasonic generators 40, and a plurality of valves and pumps.

The gas-liquid mixed ozone reactors 3-1 and 3-2 are both bubbling gas-liquid mixed ozone generators (40 liters each), and the two are connected in series by air pipes according to the direction of ozone flow between the devices, so as to make full use of the ozone production raw materials. The bottom of the gas-liquid mixed ozone generators 3-1 and 3-2 are both equipped with pumps and pipelines for sucking the reaction liquid to make the reaction liquid flow slowly downward, so that the ozone bubbles float upward and the reaction liquid flows downward in the opposite direction, so as to increase the reaction opportunity of ozone and manganate solution and improve the yield of permanganate; the pumps and pipelines at the bottom are also used as liquid flow pump tube agitators to reflux the reaction liquid into the gas-liquid mixed ozone reactor. A through-hole partition 41-3 is also added to the gas-liquid mixed ozone reactor 3-2 to reduce the ozone bubbles from the reaction liquid directly escaping upward. The two gas-liquid mixed ozone generators 3-1 and 3-2 are each equipped with a thermometer, a liquid level meter, a photoelectric colorimeter, a cold and hot temperature exchanger, and a through-hole partition and a titanium metal coated with iridium oxide on the through-hole partition as a reaction catalyst. Among them, the reaction catalyst 34-1 is a titanium metal coated with iridium oxide in the shape of a grid block, and the reaction catalyst 34-2 is a titanium metal coated with iridium oxide on the surface, and its appearance is strip and granular.

The sensor 16-1 is a liquid level meter, 16-2 is a thermometer, 16-3 is a photoelectric colorimeter, 16-4 is a liquid level meter, 16-5 is a thermometer, 16-6 is a photoelectric colorimeter, 16-7 is an ORP meter, 16-8 is a liquid level meter, 16-9 is a pH meter, 16-10 is an ORP meter, 16-11 is a liquid level meter, 16-12 is a liquid level meter, 16-3 is a hydrometer, and 16-14 is an ORP meter.

The oxygen source device 2 is an oxygen production electrolytic cell 4 with an electrolytic cell partition, and its electrolyte is a potassium hydroxide solution 26. The oxygen produced by the oxygen production electrolytic cell 4 is washed by the oxygen water washing tank 7 and condensed and dried by the freeze dryer 9, and then introduced to the ozone generator 1 to produce ozone, and is supplied to two gas-liquid mixed ozone generators for oxidation reaction. The hydrogen produced by the oxygen production electrolytic cell 4 is used for hydrogenolysis, hydrogenation and reduction of the organic waste liquid 38-1.

There are three chemical reaction tanks 32 in the device of this embodiment; the chemical reaction tank 32-1 is used for hydrogenolysis, hydrogenation and reduction treatment of organic waste liquid 38-1 by hydrogen gas generated by electrolysis; the chemical reaction tank 32-2 is used for oxidation treatment of alkaline organic waste liquid using potassium permanganate solution 23, wherein the tank is equipped with a liquid flow pump tube agitator, an ORP meter, a liquid level meter, and a pH meter; the chemical reaction tank 32-3 is used for reacting the potassium permanganate solution with the additional manganese dioxide 22-3 and the recycled manganese dioxide 22-2 to prepare the production raw materials of potassium manganate, wherein the tank is equipped with a liquid level meter, a hydrometer, and an ORP meter, and an ultrasonic generator 40 is also installed on the tank body of the chemical reaction tank 32-3 to speed up the reaction speed.

The temporary storage tank 11-1 is used for temporarily storing potassium permanganate solution products, the temporary storage tank 11-2 is used for storing recycled manganese dioxide 22-2, the temporary storage tank 11-3 is used for storing treated waste liquid 38-3, and the temporary storage tank 11-4 is used for storing potassium hydroxide solution.

The solid-liquid separator 10-1 is a filter for performing solid-liquid separation on the potassium permanganate product of the gas-liquid mixed ozone reactor 3-1. The solid-liquid separator 10-2 is a filter press for performing solid-liquid separation on the organic waste liquid 38-2 after treatment to collect the manganese dioxide for reuse.

The ultrasonic generator 40-1 is installed outside the external liquid box of the bubbling gas-liquid mixing ozone generator 3-2, and the ultrasonic generator 40-2 is placed in the external liquid box of the chemical reaction tank 32-3.

The whole set of devices in this embodiment is controlled by a program logic controller 15. The cathode tank area of the oxygen-producing electrolytic cell 4 is connected to the buffer tank 12-1 by a cathode liquid self-circulating pipeline, and the hydrogen gas outlet of the buffer tank 12-1 is connected to the vacuum ejector air inlet of the chemical reaction tank 32-1 by an air pipe; the anode tank area of the oxygen-producing electrolytic cell 4 is connected to the buffer tank 12-2 by an anode liquid self-circulating pipeline, and the oxygen outlet of the buffer tank 12-2 is connected to the oxygen booster pump 31-1 and connected to the oxygen washing tank 7 and the freeze dryer 9 in sequence through an air pipe; the freeze dryer 9 is connected to the ozone generator 1 by an air pipe through the oxygen booster pump 31-2; the ozone generator 1 is connected to the air inlet of the bubbling gas-liquid mixer of the gas-liquid mixing ozone reactor 3-1 by an air pipe, and the gas-liquid mixing ozone reactor 3-1 The ozone tail gas escape port is connected to the gas inlet of the bubbling gas-liquid mixer of the gas-liquid mixing ozone reactor 3-2 through a gas pipe. The tank bottom pipeline of the gas-liquid mixing ozone reactor 3-1 is connected to the solid-liquid separator 10-1 through a pipeline, and the liquid outlet of the solid-liquid separator 10-1 is connected to the liquid inlet of the temporary storage tank 11-1 through a pipeline. The tank bottom pipeline of the gas-liquid mixing ozone reactor 3-2 is connected to the liquid inlet of the temporary storage tank 11-1 through a pump and a pipeline.

The air inlet pipe of the tail gas treatment tank 14 is connected to the ozone tail gas outlet of the gas-liquid mixed ozone reaction tank 3-2 and the tail gas outlet of the chemical reaction tank 32-2 by air pipes.

The chemical reaction tank 32-3 is connected to the ozone generators 3-1 and 3-2 by pipelines. The temporary storage tank 11-4 is connected to the chemical reaction tanks 32-2 and 32-3 and the gas-liquid mixed ozone reaction tanks 3-1 and 3-2 by pipelines.

The steps of preparing potassium permanganate product in this embodiment are as follows:

1. Add the corresponding reaction raw materials into each reaction equipment, start the program logic controller to process the field data of each sensor and make the device run according to the set process flow.

2. The oxygen electrolytic cell is turned on to produce oxygen and sent to the oxygen water washing tank and freeze dryer for washing and drying through the oxygen high-pressure pump 31-1. The treated oxygen is supplied to the ozone generator for use, and the electrolytic hydrogen is led to the chemical reaction tank 32-1 for hydrogenolysis, hydrogenation and reduction reaction of the organic waste liquid.

3. Start the oxygen booster pump 31-2 and the ozone generator 1 to prepare ozone; respectively start the hot and cold temperature exchangers, liquid flow agitators, and ultrasonic generators 40-1 of the gas-liquid mixed ozone reactors 3-1 and 3-2 to allow an oxidation reaction of potassium manganate and ozone to occur in the two ozone reactors.

4. During the reaction process, the reaction liquid of the gas-liquid mixed ozone reactor 3-1 is regulated at 8°C by the hot-cold temperature exchanger 6-1, and the reaction liquid of the gas-liquid mixed ozone reactor 3-2 is regulated at 3°C by the hot-cold temperature exchanger 6-2. The program logic controller processes the sensor data installed in each gas-liquid mixed ozone reactor and controls the oxidation reaction process, and guides the ozone exhaust gas to the exhaust gas processor 14 for environmental protection treatment.

5. The chemical reactor 32-1 performs hydrogenolysis, hydrogenation and reduction reactions on the organic waste liquid 38-1 and its hydrogen tail gas is discharged through the hydrogen exhaust pipe 8. The chemical reactor 32-2 uses potassium permanganate to perform oxidation reaction on the organic waste liquid 38-2 and feeds the produced manganese dioxide into the chemical reaction tank 32-3 after solid-liquid separation. The ultrasonic generator 40-2 is started to prepare the potassium manganate solution for raw material recycling.

6. Oxidation process: When the photoelectric colorimeter of sensor 16-3 reaches the set value and the reaction time is reached according to the time control, it means that the preparation of potassium permanganate product in the gas-liquid mixed ozone reactor 3-1 is completed, and the oxygen production electrolyzer is shut down.

7. The oxygen water washing tank, freeze dryer, oxygen booster pump, ozone generator and liquid flow agitator are then shut down according to the time control, and the valves 17-4 and 17-5 are opened to take out the potassium permanganate solution respectively. The solid potassium permanganate product in the gas-liquid mixed ozone reactor 3-1 is separated by the solid-liquid separator 10-1 and then collected.

8. The manganese dioxide 22-2 separated from the solid-liquid separator 10-2 is fed back into the reactor 32-3 to be used as a raw material for preparing potassium manganate.

9. After the produced products are collected, the pumps 18-12 to 18-15 are restarted to add production raw materials to the gas-liquid mixed ozone reactors 3-1 and 3-2, and the production program is entered again under the control of the program logic controller.

The reaction solution process parameters of this embodiment 4 are listed in Table 1.

Table 1

Claims (20)

A method for preparing permanganate, characterized in that it comprises the following steps: Placing a solution mixture containing manganate and a strong alkaline substance in a gas-liquid mixed ozone reactor to undergo an oxidation reaction with ozone to generate permanganate; When the amount of permanganate generated in the mixture reaches the concentration and/or weight set in the process, the reaction is considered to be completed, and the product containing permanganate is collected. The method for preparing permanganate according to claim 1, characterized in that the manganate is sodium manganate and/or potassium manganate; the strong alkaline substance is an inorganic base, specifically one or more selected from sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate. The method for preparing permanganate according to claim 2, characterized in that the concentration of the strong alkaline substance in the solution mixture is not less than 0.8 mol/L based on the cations it provides. The method for preparing permanganate according to claim 3, characterized in that the strong alkaline substance contains sodium hydroxide and/or potassium hydroxide. The method for preparing permanganate according to claim 4, characterized in that the solution mixture also includes manganese dioxide or permanganate. The method for preparing permanganate according to claim 4 or 5, characterized in that manganate prepared by the neutralization reaction of manganese dioxide and permanganate is used as a raw material; wherein the permanganate participating in the neutralization reaction is prepared by an oxidation reaction of manganate and ozone. The method for preparing permanganate according to claim 6, characterized in that the gas-liquid mixing ozone reactor is a gas-liquid mixer, specifically a bubbling gas-liquid mixer and/or a vacuum jet gas-liquid mixer. The method for preparing permanganate according to claim 7, characterized in that the temperature range of the oxidation reaction is 3 to 75°C. The method for preparing permanganate according to claim 8 is characterized in that the reaction liquid in the gas-liquid mixed ozone reactor is physically stirred, and/or an ultrasonic generator is used to disperse and refine the ozone bubbles. The method for preparing permanganate according to claim 9 is characterized in that, during the oxidation reaction, iridium oxide is placed in a gas-liquid mixed ozone reactor as a reaction catalyst. The method for preparing permanganate according to claim 10, characterized in that the reaction catalyst is a metal substrate with iridium oxide coated on the surface. The method for preparing permanganate according to claim 11 is characterized in that ozone is input from the bottom or the lower middle part of the gas-liquid mixed ozone reactor, and a liquid extraction pipe is provided at the bottom or the lower middle part of the gas-liquid mixed ozone reactor, and ozone bubbles are used to float upward from the bottom to form a reverse motion with the reaction liquid to increase the chance of contact reaction; and At least one through-hole partition is placed in the ozone reactor at and/or below the liquid level of the reaction liquid to reduce the direct escape of ozone in the reaction liquid. The method for preparing permanganate according to claim 12 is characterized in that the obtained permanganate is used for oxidation reaction, and manganese dioxide is recovered from the waste liquid produced after the reaction, and then used as a raw material to re-prepare permanganate to achieve the recycling of manganese; the manganese dioxide is specifically recovered in the following manner: 1) the manganese dioxide generated after the use of permanganate is collected and recycled as a raw material; 2) for the divalent manganese salt generated after the use of permanganate, the pH value of the manganese-containing waste liquid is increased to make it alkaline, neutral or even weakly acidic, and then an oxidant is added to convert the divalent manganese into manganese dioxide and then collected as a raw material for recycling, and the oxidant is selected from persulfate, chlorine, hypochlorite, sodium chlorate, hydrogen peroxide, or a combination of more than one. The method for preparing permanganate according to claim 12 is characterized in that a mixture containing a relatively high concentration of potassium manganate is reacted with ozone in a gas-liquid mixed ozone reactor so that the potassium permanganate generated by the reaction is easily crystallized from the reaction solution to form a potassium permanganate solid product. A device for preparing permanganate using the preparation method according to claim 1, characterized in that it includes an ozone generator and an oxygen source device connected thereto, and a gas-liquid mixed ozone reactor. The device for preparing permanganate according to claim 15, characterized in that the oxygen source equipment is one or more of an oxygen cylinder, a liquid oxygen cylinder, a chemical oxygen reactor, and an oxygen electrolyzer; The gas-liquid mixing ozone reactor is specifically a bubbling gas-liquid mixer and/or a jet gas-liquid mixer; the ozone output port of the ozone generator is connected to the gas input port of the gas-liquid mixing ozone reactor through an air pipe. The device for preparing permanganate according to claim 16 is characterized in that when a bubbling gas-liquid mixer is used as a gas-liquid mixed ozone reactor, an upper through-hole baffle is provided in the gas-liquid mixed ozone reactor at or below the liquid level to prevent ozone bubbles from escaping directly upward. The device for preparing permanganate according to claim 17 is characterized in that a temporary storage tank is added for temporarily storing solid materials and solutions; a chemical reaction tank is added for preparing raw materials for the production of manganate solution and recovering manganese compounds in waste liquid for reaction; and a solid-liquid separator is added for solid-liquid separation of the solid-liquid mixture. The device for preparing permanganate according to claim 18 is characterized in that a hot and cold temperature exchanger is additionally provided; the hot and cold temperature exchanger is installed on the gas-liquid mixed ozone reactor and/or on the temporary storage tank and/or on the chemical reaction tank. The device for preparing permanganate according to claim 19 is characterized in that when more than one gas-liquid mixed ozone reactor is used, two or more gas-liquid mixed ozone generators are connected in series through a gas pipeline according to the flow direction of ozone to form a two-stage or multi-stage series gas-liquid mixed ozone reactor, so that ozone can be fully utilized in the reaction process.