阅读说明：本技术 一种利用闭路循环喷雾干燥机制备高氯酸钾粉体的方法 (Method for preparing potassium perchlorate powder by using closed-loop circulating spray dryer ) 是由 陈尧辉 吴展强 刘丹 文桥 杨冬丽 万元洋 刘大川 于 2019-09-29 设计创作，主要内容包括：本发明公开了一种利用闭路循环喷雾干燥机制备高氯酸钾粉体的方法,以高氯酸钾固体为原料,将其制成高氯酸钾溶液后,采用闭路循环喷雾干燥机对所述高氯酸钾溶液进行喷雾,制得所述高氯酸钾粉体。本发明以高氯酸钾为原料,利益闭路循环喷雾干燥机制备高氯酸钾粉体,闭路循环干燥机体积小,实现了隔绝氧气,保证了生产过程的安全可靠性,生产效率高,可连续运作,价格低,容易进行工业化生产,制得的高氯酸钾粒径小、原料利用率高,生产成本低；设备投入少,生产工艺简单且周期大大缩短；整个生产过程近乎零排放,绿色环保；具有简单高效、能耗低、成本低、安全、杂质低和粒径小的特点。(The invention discloses a method for preparing potassium perchlorate powder by using a closed cycle spray dryer. The potassium perchlorate is used as a raw material, the closed-loop circulation spray dryer is benefited to prepare the potassium perchlorate powder, the closed-loop circulation spray dryer is small in size, oxygen is isolated, the safety and reliability of the production process are guaranteed, the production efficiency is high, the continuous operation can be realized, the price is low, the industrial production is easy to carry out, and the prepared potassium perchlorate is small in particle size, high in raw material utilization rate and low in production cost; the equipment investment is less, the production process is simple, and the period is greatly shortened; the whole production process is almost zero-emission, green and environment-friendly; has the characteristics of simplicity, high efficiency, low energy consumption, low cost, safety, low impurity and small particle size.)

1. A method for preparing potassium perchlorate powder by using a closed cycle spray dryer is characterized by comprising the following steps: the method is characterized in that potassium perchlorate powder is prepared by using a potassium perchlorate solid as a raw material and spraying the potassium perchlorate solution by adopting a closed cycle spray dryer after the potassium perchlorate solution is prepared.

2. The method for preparing potassium perchlorate powder by using a closed cycle spray dryer as claimed in claim 1, which is characterized by comprising the following steps:

(1) adding deionized water into a preparation tank, adding potassium perchlorate solids, stirring for 10-30 min, filtering by using a microporous filter, and collecting filtrate to obtain potassium perchlorate solution;

(2) and pumping the prepared potassium perchlorate solution into a feed liquid chamber of a closed-loop circulating spray dryer, controlling a drying system, starting a feeding diaphragm pump when the oxygen concentration of the drying system reaches 0.2-2.5%, controlling the flow rate to be 0.2-20 mL/s, pumping the potassium perchlorate solution into an atomizer positioned in a spray drying tower for spray drying, and collecting a dried substance to obtain the potassium perchlorate powder.

3. The method for preparing potassium perchlorate powder by using a closed cycle spray dryer as claimed in claim 2, characterized in that: in the step (1), the pore diameter of the microporous filter is 0.2-1 μm.

4. The method for preparing potassium perchlorate powder by using a closed cycle spray dryer as claimed in claim 2, characterized in that: in the step (1), the purity of the potassium perchlorate solid is more than 90%, and the volume ratio of the potassium perchlorate solid to the deionized water is 1 (60-100).

5. The method for preparing potassium perchlorate powder by using a closed cycle spray dryer as claimed in claim 2, characterized in that: in the step (1), the mass concentration of the potassium perchlorate solution is 1.0-1.6%.

6. The method for preparing potassium perchlorate powder by using a closed cycle spray dryer as claimed in claim 2, characterized in that: in the step (2), the drying system is controlled to have the inlet air temperature of the drying steam of 75-120 ℃, the outlet air temperature of 40-80 ℃ and the pressure in the tower of 0.5-3.5 kPa.

7. The method for preparing potassium perchlorate powder by using a closed cycle spray dryer as claimed in claim 2, characterized in that: in the step (2), the particle size of the potassium perchlorate powder is 5-100 μm.

8. The method for preparing potassium perchlorate powder by using a closed cycle spray dryer as claimed in claim 2, characterized in that: in the step (2), mixed solvent steam is generated when spray drying is carried out in the atomizer, dust attached to gas is subjected to dust removal treatment through a cyclone separator and a filter by an induced draft fan, the mixed solvent gas after dust removal is condensed into liquid through a condenser, the liquid is discharged out of the condenser through a gas-liquid separator, and nitrogen serving as a drying medium is continuously heated and then serves as a drying carrier to re-circulate in the system to dry the material.

9. The method for preparing potassium perchlorate powder by using a closed cycle spray dryer as claimed in claim 2, characterized in that: in the step (2), before the potassium perchlorate solution enters the atomizer, nitrogen gas heated to 700-800 ℃ is filled into a tower body of a spray drying tower.

Technical Field

The invention belongs to the technical field of potassium perchlorate production, and particularly relates to a method for preparing potassium perchlorate powder by using a closed cycle spray dryer.

Background

Potassium perchlorate is an inorganic substance of white powder or orthorhombic system crystal, has strong oxidizing property, poses a risk of causing combustion and explosion when contacting or mixing with organic substances, reducing agents, and combustibles, and dry solid potassium perchlorate causes explosion when being impacted and shaken, and therefore needs to be stored in a sealed shade. Density 2.52g/cm³The melting point is 610 ℃, the molecular weight is 138.55, the catalyst can be dissolved in water (1.5g/100g), is difficult to dissolve in ether and ethanol, has stable property compared with potassium chlorate, can be decomposed into potassium chloride and oxygen at the melting point, and the decomposition reaction is accelerated when potassium chloride, potassium bromide, potassium iodide, copper, iron and the like exist. Can be used as smoke agent, igniting agent, oxidant and chemical analysis reagent, and can be used for explosive, fireworks and safety match, luminous signal agent, chemical analysis reagent, smoke agent, igniting agent and oxidant, etc. Potassium perchlorate has the following uses: 1. the explosive is used for photography and fireworks; 2. the pharmaceutical industry is used as antipyretic and diuretic agents; 3. used as analytical reagent, oxidant and solid rocket fuel.

At present, there are some literature on the preparation of potassium perchlorate powders, such as:

1. patent application CN201510750048.9 discloses a spherical potassium perchlorate production process, and the method for preparing the spherical potassium perchlorate disclosed by the invention comprises the following steps: potassium perchlorate is used as a raw material, potassium perchlorate saturated liquid is added, the mixture is heated to 95-100 ℃ to be melted and settled to obtain refined liquid, then the refined liquid is mixed with circulating potassium perchlorate saturated liquid with the concentration of 20-30 g/l at the temperature of 25-30 ℃, and crystals with the solid grain diameter of more than 200 mu m are prepared by heat exchange of a tube type heat exchanger. And then the potassium perchlorate finished product with the average grain diameter far larger than 200 mu m is obtained by centrifugal separation and drying in a fluidized bed dryer. However, the main disadvantages of the method of this patent application are: the method has the advantages of multiple required devices, long period, complex production process and high production cost; secondly, raw materials need to be heated and melted, and energy consumption is high; the process requires that the product is always in a saturated state and is recycled, so that the risk of introducing impurities exists; the dryer of the fluidized bed used is dry, oxygen is not isolated in the process, explosion is easy to cause, the dryer is unsafe, and potassium perchlorate waste gas is generated to pollute the environment; the particle size of the product is more than 200 mu m, and the particle size is too large, so that the requirement of enterprises on smaller-particle-size potassium perchlorate cannot be met.

2. Patent application CN201710688010.2 discloses a preparation process of potassium perchlorate, which comprises heating and dissolving industrial sodium chlorate, adding barium hydroxide solution, filtering, electrolyzing, heating, adding potassium chloride solution, cooling and crystallizing, adding water, heating and dissolving, cooling and crystallizing, washing, drying and crushing to obtain a finished product. The method is simple and practical, has low manufacturing cost, and is suitable for mass production of the product. However, the main disadvantages of the method of this patent application are: firstly, the process flow is complicated, the period is long, and a large amount of manpower is required; secondly, electrolysis and repeated heating are needed in the processing process, and energy consumption is too large; the production process uses too many large devices such as heating, electrolysis, crystallization, drying, crushing and the like, the equipment investment cost is too high, and the energy consumption is large; the production process is open in the atmospheric environment, so that the explosion is easily caused and the production process is unsafe; the purity of the product is lower than 99 percent, the impurity content is high, further purification is needed when the product is used in industrial production, and the enterprise cost is increased.

3. Patent application CN201510665743.5 discloses a method and a device for producing potassium perchlorate; include to use potassium chloride as the raw materials, carry out the metathesis reaction with potassium chloride and sodium perchlorate, obtain the potassium perchlorate mother liquor through cooling, centrifugal separation, it is with freezing crystallization device for the potassium perchlorate mother liquor freezing crystallization, freezing crystallization device includes the heat exchanger, the heat exchanger is arranged in the potassium perchlorate mother liquor, realizes the direct heat exchange of mother liquor and refrigerant, can not lead to the fact the loss of potassium perchlorate because of the temperature supercooling or the super-high of mother liquor, and device simple structure, reasonable produce efficient, energy resource consumption is low, the manufacturing cost of reduction potassium perchlorate that can be by a wide margin. However, the main disadvantages of the method of this patent application are: firstly, the product prepared by the method is a crystallized product, the particle size and the water content of the crystallized product do not meet the requirements of industrial requirements, and the crystallized product cannot be directly used as an industrial production raw material; secondly, the obtained product is not purified, and the impurity content of the product is too high; thirdly, a large amount of chemical waste liquid is generated after the process centrifugation and crystallization precipitation, and the environment is polluted if the chemical waste liquid is directly discharged; if the waste water is discharged after being treated, the cost is too high; the technological process uses a reaction device, a cooling device, a centrifugal device, a refrigerating device and a crystallizing device, the equipment investment is high, the production period is long, and a large amount of manpower is required.

As can be seen, although there are a number of prior art documents relating to the preparation of potassium perchlorate powders, various problems remain. Therefore, the preparation method of the potassium perchlorate powder which is simple, efficient, low in energy consumption, low in cost and safe is especially important.

Disclosure of Invention

The invention provides a method for preparing potassium perchlorate powder by using a closed cycle spray dryer to solve the technical problems. The potassium perchlorate is used as a raw material, the closed-loop circulation spray dryer is benefited to prepare the potassium perchlorate powder, the closed-loop circulation spray dryer is small in size, oxygen is isolated, the safety and reliability of the production process are guaranteed, the production efficiency is high, the continuous operation can be realized, the price is low, the industrial production is easy to carry out, and the prepared potassium perchlorate is small in particle size, high in raw material utilization rate and low in production cost; the equipment investment is less, the production process is simple, and the period is greatly shortened; the whole production process is almost zero-emission, green and environment-friendly; has the characteristics of simplicity, high efficiency, low energy consumption, low cost, safety, low impurity and small particle size. The method has the advantages that the yield is high when the potassium perchlorate powder is prepared, the yield is 95-99%, the production period is short and is as low as 0.84h/kg, the cost for producing the potassium perchlorate powder with the same weight is low, the production cost is as low as 120 yuan/kg, the particle size of the produced potassium perchlorate powder is small, the particle size of the potassium perchlorate powder is as low as 5 mu m, and the particle size is not higher than 100 mu m.

In order to achieve the above purpose, the invention adopts the following technical scheme:

a method for preparing potassium perchlorate powder by using a closed-loop cycle spray dryer is characterized in that potassium perchlorate solid is used as a raw material and is sprayed by using the closed-loop cycle spray dryer after being prepared into potassium perchlorate solution, so that the potassium perchlorate powder is prepared.

Further, the method for preparing the potassium perchlorate powder by using the closed cycle spray dryer comprises the following steps:

(1) adding deionized water into a preparation tank, adding potassium perchlorate solids, stirring for 10-30 min, filtering by using a microporous filter, and collecting filtrate to obtain potassium perchlorate solution;

(2) and pumping the prepared potassium perchlorate solution into a feed liquid chamber of a closed-loop circulating spray dryer, controlling a drying system, starting a feeding diaphragm pump when the oxygen concentration of the drying system reaches 0.2-2.5%, controlling the flow rate to be 0.2-20 mL/s, pumping the potassium perchlorate solution into an atomizer positioned in a spray drying tower for spray drying, and collecting a dried substance to obtain the potassium perchlorate powder.

Further, in the step (1), the pore size of the microporous filter is 0.2 to 1 μm.

Further, in the step (1), the purity of the potassium perchlorate solid is more than 90%, and the volume ratio of the potassium perchlorate solid to the deionized water is 1 (60-100).

Further, in the step (1), the mass concentration of the potassium perchlorate solution is 1.0-1.6%.

Further, in the step (2), the drying system is controlled to have the inlet air temperature of the drying steam of 75-120 ℃, the outlet air temperature of 40-80 ℃ and the pressure in the tower of 0.5-3.5 kPa.

Further, in the step (2), the particle size of the potassium perchlorate powder is 5 to 100 μm.

Further, in the step (2), mixed solvent steam is generated during spray drying in the atomizer, dust attached to gas is subjected to dust removal treatment through a cyclone separator and a filter by an induced draft fan, the mixed solvent gas after dust removal is condensed into liquid through a condenser, the liquid is discharged out of the condenser through a gas-liquid separator, and nitrogen serving as a drying medium is continuously heated and then used as a drying carrier to re-circulate in the system to dry the material.

Further, in the step (2), before the potassium perchlorate solution enters the atomizer, nitrogen gas heated to 700-800 ℃ is filled into the tower body of the spray drying tower.

The principle of the invention is as follows: the method comprises the steps of firstly filling high-temperature inert gas (nitrogen) into a tower body of a spray drying tower, conveying dried potassium perchlorate liquid materials to a centrifugal nozzle through a diaphragm pump, atomizing the potassium perchlorate liquid materials into fine liquid drops by a centrifugal sprayer rotating at a high speed, enabling the liquid drops to be in contact with the high-temperature nitrogen in the drying tower to perform sufficient heat exchange, instantly evaporating liquid parts (solvent gas) in the materials, sinking powdery materials formed by solid parts (potassium perchlorate) into the tower bottom, and finally discharging the dried powdery materials from the tower bottom. The evaporated solvent gas is dedusted by cyclone separator, filter and other devices under the action of blower, and then condensed into liquid in condenser, and the liquid is discharged from the condenser via gas-liquid separator. Meanwhile, the inert gas (nitrogen) as the drying medium is continuously heated and then is recycled in the system as the drying carrier.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

(1) the potassium perchlorate is used as a raw material, the closed-loop circulation spray dryer is benefited to prepare the potassium perchlorate powder, the closed-loop circulation spray dryer is small in size, oxygen is isolated, the safety and reliability of the production process are guaranteed, the production efficiency is high, the continuous operation can be realized, the price is low, the industrial production is easy to carry out, and the prepared potassium perchlorate is small in particle size, high in raw material utilization rate and low in production cost; the equipment investment is less, the production process is simple, and the period is greatly shortened; the whole production process is almost zero-emission, green and environment-friendly; has the characteristics of simplicity, high efficiency, low energy consumption, low cost, safety, low impurity and small particle size.

(2) The production process of the method has low noise and almost no dust, and ensures the physical safety of the production environment of workers.

(3) The equipment used in the application is only the diaphragm pump (power 300W) and the closed-cycle spray dryer (power 2500W), the quantity of the equipment is small, the power consumption is low, the control of the equipment is totally integrated on one control panel, the operation is simple, and the normal operation can be ensured only by one person in the whole production operation. The problems of complex production process, high energy consumption, long period and high manpower and equipment investment of the original process are effectively solved. The effects of less equipment investment, low energy consumption, simple production process and greatly shortened period are realized.

(4) The production process of the device is ensured to operate in a certain pressurized inert gas (nitrogen) closed-circuit environment from the feed inlet to the discharge outlet, the inert gas used in the production process is recycled, and the discharged condensed water is pollution-free distilled water and can be directly discharged into a lower water channel, so that the problems of the original process that the risk of introducing impurities is caused, the process is free of oxygen isolation, explosion is easily caused, and the problems of insecurity, waste gas and waste liquid generation and environmental pollution are effectively solved. Isolated oxygen is crossed in whole production, stops impurity entering, has guaranteed the fail safe nature of production process and is close to zero pollution, green's effect.

(5) This application utilizes the rotatory centrifugal nebulizer of high speed of closed cycle spray dryer installation to atomize high-purity potassium perchlorate liquid material into tiny liquid drop, and the liquid drop contacts with high temperature nitrogen gas in the drying tower, carries out abundant heat exchange, and liquid part (solvent gas) is evaporated in the twinkling of an eye in the material, obtains the potassium perchlorate product. Effectively solves the problems of overlarge granularity, low purity, more impurity content and high water content existing in the prior art. The effects of low impurity content, low water content and small particle size of the produced product are realized.

(6) The method has the advantages that the yield is high when the potassium perchlorate powder is prepared, the yield is 95-99%, the production period is short and is as low as 0.84h/kg, the cost for producing the potassium perchlorate powder with the same weight is low, the production cost is as low as 120 yuan/kg, the particle size of the produced potassium perchlorate powder is small, the particle size of the potassium perchlorate powder is as low as 5 mu m, and the particle size is not higher than 100 mu m.

Detailed Description

The following is a detailed description of the embodiments of the present invention, but the present invention is not limited to these embodiments, and any modifications or substitutions in the basic spirit of the embodiments are included in the scope of the present invention as claimed in the claims.