Method for preparing permanganate and apparatus thereof

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

[0001] The present invention relates to a method for preparing a compound, in particular to a method for preparing permanganate and a device thereof. Background Art

[0002] Permanganate is a strong oxidant with a wide range of applications, but it is relatively expensive. The current industrial production process for permanganate generally involves first using manganese dioxide and sodium / potassium hydroxide through a solid-phase calcination method (calcination temperature of 250-300°C) to produce manganate. Permanganate is then produced through a disproportionation reaction or electrolysis. The disproportionation reaction involves the disproportionation of manganate into permanganate and manganese dioxide under specific solution conditions, meaning only half of the manganese is converted into permanganate. Therefore, the disproportionation reaction method doubles the calcination load, resulting in high energy consumption and low efficiency. The electrolytic oxidation method, on the other hand, places high demands on the electrolytic cell's diaphragm and consumes a lot of electricity. Its production cost and efficiency are also easily affected by current density and electrolyte temperature. There are also safety concerns caused by the release of flammable and explosive hydrogen during the electrolysis process. The high-temperature operating conditions and high energy consumption of the disproportionation reaction method, and the difficulty in process control and high power consumption of the electrolysis method, make these two existing technologies for producing permanganate more suitable for large-scale production at a specific site and unsuitable for small-scale application.

[0003] Summary of the Invention

[0004] The first object of the present invention is to provide a method for preparing permanganate, which improves the production process of the product by utilizing the process characteristics of a gas-liquid oxidation reaction to achieve safety and efficiency, thereby solving the high energy consumption and safety hazards of the prior art and enabling small-scale production. The second object of the present invention is to provide a production device for product process improvements, providing a permanganate preparation device, which achieves the first object of the present invention while meeting the requirements for production process improvements.

[0005] The first object of the present invention is achieved through the following technical solutions.

[0006] A method for preparing permanganate comprises the following steps:

[0007] A solution mixture containing manganate and a strong alkaline substance is placed in a gas-liquid mixed ozone reactor to undergo an oxidation reaction with ozone to generate permanganate;

[0008] When the amount of permanganate generated in the mixture reaches the concentration and / or weight set in the process, the reaction is considered complete, and a solution product containing permanganate or a solid-liquid mixture product containing permanganate solid is collected.

[0009] The manganate described in the present invention is sodium manganate and / or potassium manganate. The permanganate prepared in the present invention is sodium permanganate and / or potassium permanganate.

[0010] 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, and potassium bicarbonate, and can be used in 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 and allow it to smoothly undergo the 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.

[0011] The chemical reactions that occur in the gas-liquid mixed ozone reactor are shown below.

[0012] The chemical reaction formula for the oxidation reaction to produce permanganate is as follows:

[0013] 6Na2MnO4+O3+3H2O→6NaMnO4+6NaOH;

[0014] 6K2MnO4+O3+3H2O→6KMnO4+6KOH.

[0015] 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.

[0016] When the mixture contains manganese dioxide, permanganate undergoes a redox reaction with it to form manganate. The specific chemical reaction formula is as follows: 2MnO4 - +MnO2+4OH - →3MnO4 2- +2H2O; 2MnO4 - +MnO2+2CO3 2- →3MnO4 2- +2CO2↑; 2MnO4 - +MnO2+4HCO3 - →3MnO4 2- +2H2O+4CO2↑.

[0017] The manganate generated above can be further oxidized with ozone to produce permanganate.

[0018] The present invention has no restrictions on the method of obtaining manganate. Manganate can be directly used as the raw material, or it can be obtained by the neutralization reaction of manganese dioxide and permanganate. When the manganate is obtained by the neutralization reaction of manganese dioxide and permanganate, the permanganate involved in the neutralization reaction is externally added permanganate and / or permanganate obtained by an oxidation reaction of manganate with ozone. This solution avoids the high temperature reaction conditions required for roasting to produce manganate in the prior art, significantly reducing the energy consumption required for the reaction.

[0019] As a preferred embodiment of the present invention, manganate is prepared as a raw material of the present invention by using permanganate generated by an oxidation reaction of manganate with ozone and manganese dioxide for a neutralization reaction. When permanganate generated by an oxidation reaction of manganate with ozone is used to neutralize manganese dioxide to produce manganate, a portion of the manganese element in the resulting manganate comes from manganese dioxide, meaning that only a portion of the resulting permanganate is required to produce new manganate.

[0020] As can be seen from the above chemical equation, the neutralization reaction of permanganate and manganese dioxide requires the participation of a strongly basic substance. Therefore, permanganate, manganese dioxide and a strongly basic substance mixed reaction can be used to obtain a solution mixture containing manganate and a strongly basic substance according to the present invention, or a mixture further containing manganese dioxide or permanganate. If the mixture containing manganate, strongly basic substance and manganese dioxide is subjected to an oxidation reaction with ozone in a gas-liquid mixed ozone reactor, the generated permanganate can be reacted with the manganese dioxide and the strongly basic substance in the mixture to generate a new manganate, and the reaction can 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 need to add permanganate. When carbonate and / or bicarbonate are used alone as a strongly basic substance to participate in the neutralization reaction of permanganate and manganese dioxide, its speed of response is slower, and carbon dioxide gas is separated out. 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 correspondingly increased.

[0021] 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.

[0022] The temperature range of the oxidation reaction is 3-75°C. Since the entire oxidation process is a gas-liquid mixture reacting with ozone, the oxidation reaction temperature is preferably 8-60°C to ensure the fluidity of the solution and to promote the oxidation reaction by temperature while avoiding decomposition of the generated permanganate due to excessively high temperature. More preferably, the oxidation reaction temperature is 20-45°C.

[0023] The ozone described in the present invention preferably comes from an ozone generator. The ozone generator's oxygen source can be selected from one or a combination of commercial oxygen, commercial liquid oxygen, oxygen produced by chemical methods, and oxygen produced by electrolysis. Preferably, oxygen is produced by chemically reacting hydrogen peroxide with manganese dioxide, and / or by using water electrolysis oxygen production equipment. This process is simple and the cost of producing oxygen is low.

[0024] The present invention may also be improved as follows: in order to better facilitate the contact reaction between the reaction liquid and ozone during 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, thereby better participating in the oxidation reaction with manganate.

[0025] The present invention can be improved as follows: in the oxidation reaction process, iridium oxide IrOx is placed in a mixture participating in the reaction in a gas-liquid mixed ozone reactor 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 bar and / or granular and / or grid 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 the reaction catalyst can avoid the solid-liquid separation process of the product solution and the reaction catalyst after the oxidation reaction. To ensure that the iridium oxide coating on the metal substrate can evenly cover the metal substrate and achieve the expected protective effect, its service life is set according to the process production conditions and the iridium oxide coating on the metal substrate is promptly recoated to ensure the safety and effectiveness of the coating.

[0026] The present invention can also be improved as follows: when oxygen produced by electrolysis is used as the oxygen source for 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 washed oxygen 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.

[0027] The present invention can also be improved by introducing ozone into the gas-liquid mixing ozone reactor from the bottom or lower middle portion thereof, and providing a liquid extraction pipe at the bottom or lower middle portion of the gas-liquid mixing ozone reactor. This utilizes the upward buoyancy of ozone bubbles from the bottom to form a counter-movement with the reaction liquid, thereby increasing the chance of a contact reaction. Preferably, after adding the counter-movement condition of the reactants, at least one perforated baffle is placed within the gas-liquid mixing ozone reactor, located at and / or below the reaction liquid level, to reduce direct escape of ozone from the reaction liquid and improve product yield.

[0028] 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 a raw material for the preparation of the present invention, which not only reduces environmental pollution but also saves production costs. In particular, in the processes using permanganate in various fields, the permanganate prepared by the present invention is used to carry out an 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 using the method of the present invention, thereby realizing the recycling of manganese and greatly reducing the cost of use. Specifically, the following methods are used to recover manganese dioxide: 1) the manganese dioxide generated after the use of permanganate is recovered as a raw material for the preparation of the present invention; 2) the divalent manganese salt generated after the use of permanganate is raised to a pH value of the manganese-containing waste liquid to convert it to an alkaline, neutral or even weakly acidic condition, and then an oxidant is added to convert the divalent manganese into manganese dioxide, which is then recovered as a raw material for the preparation of the present invention for recycling, wherein the oxidant is selected from one or more combinations of persulfate, chlorine, hypochlorite, sodium chlorate and hydrogen peroxide.

[0029] 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.

[0030] The present invention can also be improved as follows: because 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, to produce solid permanganate, 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 solid potassium permanganate product. In this improved solution, the suitable potassium manganate concentration varies depending on the concentration of the strongly alkaline substance in the mixture. If no potassium permanganate crystallizes or the amount of crystallization is less than the process requirements during the reaction, the potassium manganate concentration in the reaction mixture is increased.

[0031] The second object of the present invention is achieved through the following solutions.

[0032] A permanganate preparation device is characterized by comprising an ozone generator, an oxygen source device connected thereto, and a gas-liquid mixed ozone reactor.

[0033] The ozone generator is a commercially available product.

[0034] 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.

[0035] The gas-liquid mixing 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 mixing ozone reactor via a gas pipe. The gas-liquid mixing ozone reactor is made of corrosion-resistant materials.

[0036] The present invention can be improved as follows: when a bubbling gas-liquid mixer is used as a gas-liquid mixing 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 partition is provided in the gas-liquid mixing 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.

[0037] 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.

[0038] The present invention can be improved as follows: a hot and cold temperature exchanger is added to make the working temperature of the reaction liquid meet the process requirements. The hot and cold temperature exchanger is installed on the gas-liquid mixed ozone reactor and / or the temporary storage tank and / or the chemical reaction tank.

[0039] The present invention can also be improved by selecting a chemical oxygen production reactor and / or an oxygen electrolyzer to produce oxygen, and installing an oxygen pressure pump on the pipeline between the chemical oxygen production reactor and / or an oxygen electrolyzer to pressurize the oxygen and supply it to the ozone generator. Preferably, the oxygen produced by the oxygen electrolyzer is washed with water and dehydrated at low temperature before being supplied to the oxygen pressure pump, which then supplies oxygen to the ozone generator, thereby improving the safety and ozone yield of the ozone production equipment.

[0040] The present invention can also be improved as follows: an oxygen water washing tank is added to wash the oxygen collected from the oxygen electrolytic cell to remove acid and alkaline impurities. Specifically, an air pipe is connected between the anode tank area of ​​the oxygen electrolytic cell and the oxygen water washing tank.

[0041] The present invention can also be improved by adding a freeze dryer to dry the oxygen by condensing water in the oxygen at low temperature, thereby increasing 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.

[0042] 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.

[0043] 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 achieve uniform concentration and temperature of the substances in the container. The agitator is selected from one or more combinations of an impeller agitator, a liquid flow agitator, and an ultrasonic generator according to its structure. Preferably, when a bubbling gas-liquid mixer is used as the gas-liquid mixing ozone reactor, a pump and a pipeline are provided at its bottom as a liquid flow agitator to pump the reaction liquid so that the reaction liquid flows slowly downward, thereby moving in the opposite direction of the upward-rising ozone bubbles to increase the chance of contact reaction between ozone and manganate, thereby improving 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 are 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 closely attached to the container to which ultrasonic waves are to be applied.

[0044] The present invention can also be improved as follows: a temporary storage tank is added for temporarily storing 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.

[0045] 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 via a pipeline.

[0046] The present invention can also be improved by adding a buffer tank 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.

[0047] The present invention can also be improved by adding an exhaust gas treatment unit to safely and environmentally treat the exhaust gas emitted by each tank in the device. The exhaust gas treatment unit is specifically a vacuum ejector or spray tower within the gas-liquid mixer. It is connected to the exhaust gas outlets of each tank in the device via air pipes. Absorption of ozone exhaust gas within the exhaust gas treatment unit is particularly important, and an acidic ferrous salt solution is used as the absorption liquid to reduce environmental pollution.

[0048] The present invention can also be improved by adding a programmable logic controller (PLC) and a sensor to enable automated process control of the device, ensuring 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 gauge, and a thermometer. The signal input of the programmable logic controller is connected to the signal output of the sensor, and the signal output of the programmable logic controller is connected to the signal input of at least one device within the device, such as a pump, a valve, an ozone generator, a hot / cold temperature exchanger, a stirrer, and an oxygen electrolyzer.

[0049] 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 gas pipelines 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.

[0050] Compared with the prior art, the present invention has the following beneficial effects.

[0051] 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 permanganate production process, and avoids the problems of high power consumption, production cost, and easily affected efficiency of the electrolysis method in the prior art permanganate production process. It also avoids the high temperature operating conditions required by the prior art method and is also suitable for small-scale application.

[0052] 2. The present invention adopts gas-liquid oxidation reaction to prepare permanganate, preferably adopts catalytic oxidation reaction to improve production efficiency, make the production process safer and energy-saving.

[0053] 3. The process for preparing permanganate according to the present invention does not generate any new pollutants and can also recycle the manganese dioxide produced after the use of the permanganate, thereby reducing pollution to the environment and greatly reducing the cost of using the permanganate.

[0054] 4. The device for preparing permanganate of the present invention is simple, requires little investment, has low maintenance cost and high economic benefit.

[0055] 5. The permanganate preparation device of the present invention can be installed in the factory where the permanganate is used. The low-valent manganese produced after the waste liquid treatment is recovered as the manganese dioxide raw material required by the present invention, thereby achieving the environmental protection, energy saving and recycling process requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] FIG1 is a schematic structural diagram of the permanganate preparation device of Example 1.

[0057] FIG2 is a schematic structural diagram of the permanganate preparation device of Example 2.

[0058] FIG3 is a schematic structural diagram of the permanganate preparation device of Example 3.

[0059] FIG4 is a schematic structural diagram of the permanganate preparation device of Example 4; FIG4-1, FIG4-2 and FIG4-3 are partial views of FIG4 respectively, and the three constitute a complete schematic structural diagram of the permanganate preparation device of Example 4.

[0060] FIG5 is a schematic structural diagram of a gas-liquid mixing ozone reactor according to the present invention, wherein the gas-liquid mixing ozone reactor is a bubbling gas-liquid mixer.

[0061] Figures: 1-ozone generator, 2-oxygen source equipment, 3-gas-liquid mixed ozone reactor, 4-oxygen electrolytic cell, 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-programmable 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 pressure 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.

[0062] 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 refers to one of the oxygen source devices, and oxygen source device 2-2 refers to another of the oxygen source devices. DETAILED DESCRIPTION

[0063] The present invention is further described below with reference to specific examples.

[0064] The gas-liquid hybrid ozone reactor, chemical oxygen production reactor, electrolyzer, temporary storage tank, chemical reaction tank, and tail gas treatment unit used in the following examples are all manufactured by Yegao Environmental Protection Equipment Manufacturing Co., Ltd. in Foshan, Guangdong, China. The ozone generator, commercial oxygen, solid-liquid separator, sensors, programmable logic controller, oxygen booster pump, valves, and chemical raw materials are all commercially available. In addition to the above, those skilled in the art can also select other products with similar performance to those listed above, and any of these products can achieve the objectives of the present invention.

[0065] Figure 5 shows a schematic diagram of the structure of a gas-liquid mixing ozone reactor according to the present invention. The gas-liquid mixing ozone reactor 3 is a bubbling gas-liquid mixing ozone generator. A pipe with a valve and a pump is provided at its bottom to draw the reaction liquid, causing it to flow slowly downward. This causes ozone bubbles to rise upward while the reaction liquid flows downward in the opposite direction, increasing the reaction between ozone and manganate solution and improving the permanganate yield. The pipe also serves as a liquid flow pump agitator, returning the reaction liquid to the gas-liquid mixing ozone reactor via a liquid spray pipe 39. The gas-liquid mixing ozone reactor 3 is also provided with perforated partitions 41-1 and 41-2 to reduce the direct upward escape of ozone bubbles from the reaction liquid. Three sensors 16 are installed in the gas-liquid mixing ozone generator 3, and a reaction catalyst is placed on the perforated partition 41-2. The gas-liquid mixing ozone generator 3 is also provided with a hot and cold 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 mixing ozone generator 3, and the ultrasonic generator 40-2 is placed in the external liquid box of the gas-liquid mixing ozone generator 3. The external liquid box is loaded with clean water.

[0066] Example 1

[0067] As shown in Figure 1, the permanganate preparation device of Example 1 includes an ozone generator 1, two oxygen source devices 2, a gas-liquid mixed ozone reactor 3, a hot and cold temperature exchanger 6, an agitator 13, valves, and a pump. The oxygen source devices 2-1 and 2-2 are commercial liquid oxygen cylinders and oxygen cylinders, respectively. The gas-liquid mixed ozone generator 3 is a bubbling gas-liquid mixed ozone generator, which is an open reactor (40 liters) equipped with a bubbling gas-liquid mixer. The hot and cold temperature exchanger 6 and the 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 to detect the temperature of the reaction liquid.

[0068] The oxygen outlet pipes of oxygen source device 2-1 and oxygen source device 2-2 are each connected to ozone generator 1 via air pipes to supply oxygen for the ozone reaction. The ozone output port of ozone generator 1 is also connected to the air pipe port of the bubbling gas-liquid mixer of gas-liquid mixing ozone generator 3 via air pipes.

[0069] The steps of preparing the permanganate mixed solution product in this embodiment are as follows:

[0070] 1. Add the starting mixture to the gas-liquid mixed ozone reactor 3;

[0071] 2. Open the liquid oxygen bottle and oxygen bottle to supply oxygen to the ozone generator; start the ozone generator 1 to produce ozone and deliver the ozone to the gas-liquid mixed ozone reactor 3, where the ozone contacts the reaction liquid to carry out an oxidation reaction; start 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;

[0072] 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;

[0073] 4. Open valve 17 and start pump 18 to extract the solution product in the gas-liquid mixed ozone reactor 3.

[0074] The process parameters of the reaction solution of this embodiment 1 are listed in Table 1.

[0075] Example 2

[0076] As shown in FIG2 , the permanganate preparation apparatus of Example 2 includes an ozone generator 1, an oxygen source device 2, a gas-liquid mixed ozone reactor 3, a hot and cold temperature exchanger 6, a solid-liquid separator 10, an impeller stirrer 13, sensors 16 - 1 , 16 - 2 , and 16 - 3 , an oxygen booster pump 31 , an ultrasonic generator 40 , and multiple valves and pumps.

[0077] Oxygen source device 2 is a chemical oxygen reactor 33. The raw materials for the oxygen production reaction in chemical oxygen reactor 33 are hydrogen peroxide and a manganese dioxide catalyst. Chemical oxygen reactor 33 is equipped with a stirrer 13 (an impeller stirrer) and a sensor 16-1 (a liquid level gauge).

[0078] The gas-liquid mixing ozone reactor 3 is a vacuum jet gas-liquid mixing ozone reactor, which is a closed reactor (40 liters) equipped with a vacuum jet gas-liquid mixer 20, and sensors 16-2 and 16-3 are installed therein, which are a thermometer and a photoelectric colorimeter respectively. The hot and cold temperature exchanger 6 and the ultrasonic generator 40 are also arranged on the gas-liquid mixing ozone reactor 3.

[0079] The solid-liquid separator 10 is connected to the reaction liquid discharge pipe of the gas-liquid mixed ozone reactor 3 and is used to filter and collect the iridium oxide powder solid in the product solution.

[0080] The oxygen output port of the chemical oxygen production reactor 33 is connected to the oxygen pressure pump 31 through an air pipe, and the air outlet of the oxygen pressure 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.

[0081] In this embodiment, iridium oxide powder is used as a reaction catalyst in the oxidation reaction process.

[0082] The steps of preparing the sodium permanganate solution product in this embodiment are as follows:

[0083] 1. Add the starting mixture to the gas-liquid mixed ozone reactor 3 and add an appropriate amount of iridium oxide powder;

[0084] 2. Hydrogen peroxide and manganese dioxide are added to the chemical oxygen production reactor 33 to react and generate oxygen. The generated oxygen is supplied to the ozone generator via an oxygen pressure pump. The oxygen pressure pump and ozone generator 1 are turned on to produce ozone. After turning on pump 18-1, the ozone is introduced into the gas-liquid mixed ozone reactor 3 to mix and react with the reaction liquid. The hot and cold temperature exchanger 6 is turned on to control the temperature of the reaction liquid at 45°C. The ultrasonic generator 40 is turned on to stir the reaction liquid.

[0085] 3. After 25 hours of oxidation reaction, if the color of the reaction solution reaches the set value of the photoelectric colorimeter, the reaction is considered complete, and the chemical oxygen reactor 33, oxidation pressure pump 31, ozone generator 1, cold and hot temperature exchanger 6 and pump 18-1 are shut down;

[0086] 4. Open valve 17-2 and start pump 18-2 to collect the produced solution product containing permanganate. During the collection process, use a filter to collect the iridium oxide powder in the product solution for next use. After completion, shut down the device.

[0087] The process parameters of the reaction solution of this embodiment 2 are listed in Table 1.

[0088] Example 3

[0089] As shown in Figure 3, the permanganate production apparatus of Example 3 includes an ozone generator 1, an oxygen source device 2, a gas-liquid mixed ozone reactor 3, two hot and cold temperature exchangers 6-1 and 6-2, a solid-liquid separator 10, four temporary storage tanks 11, an agitator 13, five sensors 16, an oxygen booster pump 31, an exhaust gas processor 14, and multiple valves and pumps. Sensor 16-1 is a thermometer, 16-2 is an ORP meter, 16-3 is a photoelectric colorimeter, 16-4 is a liquid level gauge, and 16-5 is an ORP meter. Solid-liquid separator 10 is a filter press.

[0090] A sensor 16 - 1 , a hot and cold temperature exchanger 6 - 1 and a stirrer 13 are installed in the chemical oxygen production reactor 33 . The stirrer 13 is an impeller stirrer.

[0091] The gas-liquid mixing ozone generator 3 adopts a vacuum ejector structure, which is a closed reactor (40 liters) equipped with a vacuum ejector gas-liquid mixer 20, a hot and cold temperature exchanger 6, and sensors 16-2 and 16-3 installed in the reactor 3.

[0092] 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 .

[0093] In the apparatus of this embodiment, the temporary storage tank 11-1 is connected to the chemical oxygen reactor 33 via a pipeline and a pump; the chemical oxygen reactor 33 is connected to the oxygen pressure pump 31 and the ozone generator 1 via 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 via a gas pipeline; the gas-liquid mixing ozone reactor 3 is connected to the solid-liquid separator 10 via a pipeline and a pump; the solid-liquid separator 10 is connected to the temporary storage tank 11-3 via a buffer tank 12, a pump, and a pipeline; the exhaust gas processor 14 is connected to the exhaust gas outlet of each tank via an air pipe; and the exhaust gas processor 14 is connected to the temporary storage tank 11-4 via a pump pipeline.

[0094] The reaction catalyst used in this embodiment is titanium metal particles coated with iridium oxide.

[0095] The steps of preparing the sodium permanganate solution product in this embodiment are as follows:

[0096] 1. Add hydrogen peroxide to the temporary storage tank 11-1, add manganese dioxide to the chemical oxygen reactor 33, add the starting mixture involved in the reaction to the gas-liquid mixed ozone reactor 3, and add the acidic ferrous chloride solution 35 to the exhaust gas processor 14;

[0097] 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; and start the exhaust gas processor 14;

[0098] 3. During the reaction, the temperature of the reaction liquid is controlled at 20°C. The exhaust gas from the gas-liquid mixed ozone reactor 3 is directed to the exhaust gas processor 14 for environmental 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, oxidation pressure pump 31, ozone generator 1, and pump 18-2 are shut down. Valves 17-4 and 17-5 are opened, and pumps 18-3 and 18-4 are turned on. The mixture in the gas-liquid mixed ozone reactor 3 is filter-pressed, and the solution product 23 is removed and directed to the temporary storage tank 11-3 for temporary storage.

[0099] 4. The filter residue manganese dioxide 22-2 from the filter press is used for the next round of permanganate production and is added to the gas-liquid mixed ozone reactor 3 as the reaction raw material manganese dioxide 22-1.

[0100] The process parameters of the reaction solution of this embodiment 3 are listed in Table 1.

[0101] Example 4

[0102] As shown in FIG4 , the permanganate preparation apparatus of Example 4 includes an ozone generator 1, an oxygen source device 2, two gas-liquid mixed ozone reactors 3, two hot and cold temperature exchangers, an oxygen water washing tank 7, an exhaust hydrogen 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 programmable 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 multiple valves and pumps.

[0103] Both gas-liquid mixing ozone reactors 3-1 and 3-2 are bubbling gas-liquid mixing ozone generators (40 liters each). They are connected in series via gas pipes based on the direction of ozone flow between the devices, fully utilizing the ozone production raw materials. Pumps and pipes are installed at the bottom of both gas-liquid mixing ozone generators 3-1 and 3-2 to pump the reaction liquid, causing it to flow slowly downward. This allows ozone bubbles to rise upward while the reaction liquid flows downward, increasing the chance of reaction between ozone and manganate solution and improving permanganate yield. These pumps and pipes also serve as liquid flow pump and agitators, returning the reaction liquid to the gas-liquid mixing ozone reactor. A through-hole partition 41-3 is also added to gas-liquid mixing ozone reactor 3-2 to reduce the direct upward escape of ozone bubbles from the reaction liquid. Each of the two gas-liquid mixed ozone generators 3-1 and 3-2 is equipped with a thermometer, a liquid level gauge, a photoelectric colorimeter, a hot and cold temperature exchanger, and a through-hole partition. A titanium metal coated with iridium oxide is placed on the through-hole partition as a reaction catalyst. The reaction catalyst 34-1 is a grid-shaped titanium metal coated with iridium oxide, while the reaction catalyst 34-2 is a titanium metal coated with iridium oxide in the form of strips and granules.

[0104] 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.

[0105] The oxygen source device 2 comprises an oxygen-generating electrolytic cell 4 with an electrolytic cell partition. The electrolyte in the oxygen-generating electrolytic cell 4 is a potassium hydroxide solution 26. The oxygen produced by the oxygen-generating electrolytic cell 4 is washed in an oxygen water washing tank 7 and condensed and dried in a freeze dryer 9. The oxygen is then directed to the ozone generator 1 to produce ozone, which is then supplied to two gas-liquid mixing ozone generators for oxidation reactions. The hydrogen produced by the oxygen-generating electrolytic cell 4 is used for hydrogenolysis, hydrogenation, and reduction of the organic waste liquid 38-1.

[0106] The apparatus of this embodiment includes three chemical reaction tanks 32; chemical reaction tank 32-1 is used to hydrogenolyze and reduce organic waste liquid 38-1 using hydrogen generated by electrolysis; chemical reaction tank 32-2 is used to oxidize alkaline organic waste liquid using potassium permanganate solution 23, wherein the tank is equipped with a liquid flow pump tube agitator, ORP meter, liquid level meter, and pH meter; chemical reaction tank 32-3 is used to react with potassium permanganate solution using additional manganese dioxide 22-3 and recycled manganese dioxide 22-2 to prepare the production raw material of potassium manganate, and the tank is equipped with a liquid level meter, hydrometer, and ORP meter. To accelerate the reaction speed, an ultrasonic generator 40 is also installed on the tank body of chemical reaction tank 32-3.

[0107] 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.

[0108] The solid-liquid separator 10-1 is a filter for separating the potassium permanganate product from the gas-liquid mixed ozone reactor 3-1. The solid-liquid separator 10-2 is a filter press for separating the solid and liquid of the organic waste liquid 38-2 after treatment to recover the manganese dioxide for reuse.

[0109] 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.

[0110] The entire apparatus of this embodiment is controlled and operated using a programmable logic controller 15. The cathode tank section of the oxygen-producing electrolytic cell 4 is connected to the buffer tank 12-1 via a cathode liquid self-circulating pipeline. The hydrogen outlet of the buffer tank 12-1 is connected to the vacuum ejector air inlet of the chemical reaction tank 32-1 via a gas pipe. Furthermore, the anode tank section of the oxygen-producing electrolytic cell 4 is connected to the buffer tank 12-2 via an anolyte liquid self-circulating pipeline. The oxygen outlet of the buffer tank 12-2 is connected to the oxygen pressure pump 31-1, which is connected to the oxygen water washing tank 7 and the freeze dryer 9 via gas pipes. The freeze dryer 9 is connected to the ozone generator 1 via a gas pipe via the oxygen pressure 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 via a gas pipe. The ozone tail gas outlet of the gas-liquid mixing ozone reactor 3-1 is connected to the air inlet of the bubbling gas-liquid mixer of the gas-liquid mixing ozone reactor 3-2 via a gas pipe. The bottom pipe of the gas-liquid mixed ozone reactor 3-1 is connected to the solid-liquid separator 10-1 by a pipe, and the liquid outlet of the solid-liquid separator 10-1 is connected to the liquid inlet of the temporary storage tank 11-1 by a pipe. The bottom pipe of the gas-liquid mixed ozone reactor 3-2 is connected to the liquid inlet of the temporary storage tank 11-1 by a pipe through a pump and a pipe.

[0111] 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 through an air pipe.

[0112] The chemical reaction tank 32-3 is connected to the ozone generators 3-1 and 3-2 via 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 via pipelines.

[0113] The steps of preparing potassium permanganate product in this embodiment are as follows:

[0114] 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.

[0115] 2. The oxygen electrolyzer is turned on to produce oxygen, which is then 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 then supplied to the ozone generator. The electrolytic hydrogen is then directed to the chemical reaction tank 32-1 for hydrogenolysis, hydrogenation, and reduction of the organic wastewater.

[0116] 3. Start the oxygen booster pump 31-2 and the ozone generator 1 to prepare ozone; start the hot and cold temperature exchangers, liquid flow agitators, and ultrasonic generator 40-1 of the gas-liquid mixed ozone reactors 3-1 and 3-2 respectively, so that the oxidation reaction of potassium manganate and ozone occurs in the two ozone reactors.

[0117] 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.

[0118] 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 oxidize 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 as a raw material for recycling.

[0119] 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 electrolyzer is shut down.

[0120] 7. The oxygen water washing tank, freeze dryer, oxygen booster pump, ozone generator, and liquid agitator are then shut down according to the time control. Valves 17-4 and 17-5 are opened to remove the potassium permanganate solution. The solid potassium permanganate product in the gas-liquid mixed ozone reactor 3-1 is separated and collected through the solid-liquid separator 10-1.

[0121] 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.

[0122] 9. After the finished product is collected, 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 process is entered again under the control of the program logic controller.

[0123] The reaction solution process parameters of this Example 4 are listed in Table 1.

[0124] Table 1

Claims

1. A method for preparing permanganate, characterized in that: The following steps are involved: 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.

2. 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.

3. 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.

4. The method for preparing permanganate according to claim 3, characterized in that: The strong alkaline substance contains sodium hydroxide and / or potassium hydroxide.

5. The method for preparing permanganate according to claim 4, characterized in that: The solution mixture also includes manganese dioxide or permanganate.

6. The method for preparing permanganate according to claim 4 or 5, characterized in that: Manganate obtained by the neutralization reaction of manganese dioxide and permanganate is used as a raw material; wherein the permanganate involved in the neutralization reaction is obtained by an oxidation reaction of manganate and ozone.

7. 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.

8. The method for preparing permanganate according to claim 7, characterized in that: The temperature range of the oxidation reaction is 3-75°C.

9. The method for preparing permanganate according to claim 8, 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.

10. The method for preparing permanganate according to claim 9, characterized in that: During the oxidation reaction, iridium oxide is placed in a gas-liquid mixed ozone reactor as a reaction catalyst.

11. 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.

12. The method for preparing permanganate according to claim 11, characterized in that: In the gas-liquid mixed ozone reactor, ozone is input from the bottom or the lower middle part thereof, and a liquid extraction pipe is provided at the bottom or the lower middle 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; moreover, 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.

13. The method for preparing permanganate according to claim 12, characterized in that: The prepared permanganate is used for oxidation reaction, and manganese dioxide is recovered from the waste liquid produced after the reaction, and then the waste liquid is used as a raw material to re-prepare permanganate, so as to realize the recycling of manganese; the manganese dioxide is recovered specifically in the following manner: 1) the manganese dioxide generated after the use of permanganate is recovered as a raw material for recycling; 2) the divalent manganese salt generated after the use of permanganate is increased in pH value of the manganese-containing waste liquid 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 the manganese is recovered as a raw material for recycling, and the oxidant is selected from persulfate, chlorine, hypochlorite, sodium chlorate, and hydrogen peroxide, or a combination of more than one.

14. The method for preparing permanganate according to claim 12, characterized in that: In a gas-liquid mixed ozone reactor, a mixture containing a relatively high concentration of potassium manganate is used to react with ozone, so that the potassium permanganate generated by the reaction can be easily crystallized from the reaction liquid to become a potassium permanganate solid product.

15. A device for preparing permanganate using the preparation method according to claim 1, characterized in that: The invention comprises an ozone generator, an oxygen source device connected thereto, and a gas-liquid mixed ozone reactor.

16. 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 production reactor, and an oxygen production 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.

17. The device for preparing permanganate according to claim 16, characterized in that: When a bubbling gas-liquid mixer is used as the gas-liquid mixed ozone reactor, an upper through-hole partition is arranged in the gas-liquid mixed ozone reactor at or below the liquid surface to prevent ozone bubbles from escaping directly upward.

18. The device for preparing permanganate according to claim 17, characterized in that: Add temporary storage tanks to temporarily store solid materials and solutions; add chemical reaction tanks to prepare raw materials for the production of manganate solution and to recover manganese compounds in waste liquid for reaction; add solid-liquid separators to separate solid-liquid mixtures.

19. The device for preparing permanganate according to claim 18, characterized in that: A cold and hot temperature exchanger is added; 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.

20. The device for preparing permanganate according to claim 19, 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 gas pipelines 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.

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