Magnesium hydroxide continuous production process based on horizontal circulating tube type reactor
阅读说明：本技术 一种基于水平循环管式反应器的氢氧化镁连续生产工艺 (Magnesium hydroxide continuous production process based on horizontal circulating tube type reactor ) 是由 张丽 张莹 冯颖 董鑫 张建伟 于 2020-12-01 设计创作，主要内容包括：一种基于水平循环管式反应器的氢氧化镁连续生产工艺,涉及一种氢氧化镁连续生产工艺,本发明工艺采用水平循环管式反应器,连续生产氢氧化镁。以一定浓度的镁盐和沉淀剂为原料,在循环管式反应器中,镁盐与沉淀剂发生反应,生成氢氧化镁沉淀,所得沉淀经陈化、过滤、烘干,最终得到氢氧化镁产品。通过物料在管式反应器内循环,从而延长物料在反应器中的停留时间。该工艺可连续运行,产品氢氧化镁纯度高、粒径小,形貌好,产品质量稳定,工艺能耗低。(The invention discloses a continuous production process of magnesium hydroxide based on a horizontal circulating tube type reactor, and relates to a continuous production process of magnesium hydroxide. Taking magnesium salt and precipitator with certain concentration as raw materials, reacting the magnesium salt with the precipitator in a circulating tube type reactor to generate magnesium hydroxide precipitate, and aging, filtering and drying the obtained precipitate to finally obtain a magnesium hydroxide product. The residence time of the material in the reactor is prolonged by circulating the material in the tubular reactor. The process can be operated continuously, and the magnesium hydroxide product has high purity, small particle size, good appearance, stable product quality and low process energy consumption.)
1. Based on horizontal circulating pipeThe continuous production process of magnesium hydroxide in a reactor is characterized in that the process comprises the steps of solution preparation, reaction, aging, filtering and drying; the process runs continuously, a circulating pipe type reactor, a circulating pump and a circulating pipeline are adopted, and auxiliary equipment comprises a raw material storage tank, a pump, a flowmeter, a filter, an ageing tank and a dryer; the process reaction temperature is 20oC~200 oC(ii) a The concentration of the raw material magnesium salt is 0.1-2.5 mol/L, and the molar ratio of the precipitator to the raw material magnesium salt is 1-5 times of the stoichiometric value; the aging temperature is 50-200 ℃, and the aging time is 0-10 hours; the raw material magnesium salt is magnesium chloride or magnesium nitrate or magnesium sulfate magnesium salt; the precipitant is recycled or made into commodity for sale.
2. The continuous production process of magnesium hydroxide based on the horizontal circulation tube type reactor as claimed in claim 1, wherein the precipitant is lime or sodium hydroxide or ammonia gas or its alkaline substance.
3. The continuous production process of magnesium hydroxide based on the horizontal circulation tube reactor as claimed in claim 1, wherein the circulation tube reactor is a horizontal tube reactor.
4. The continuous production process of magnesium hydroxide based on the horizontal circulation tube type reactor as claimed in claim 3, wherein the horizontal tube type reactor is a long straight tube or a spiral tube.
Technical Field
The invention relates to a continuous production process of magnesium hydroxide, in particular to a continuous production process of magnesium hydroxide based on a horizontal circulating tube type reactor.
Background
The magnesium hydroxide is an inorganic chemical raw material with wide application and has very wide market application prospect.
The current methods for preparing magnesium hydroxide mainly include chemical precipitation and natural brucite processing (physical pulverization). The two magnesium hydroxide products have different properties (physical properties and chemical component content), different use effects and very large market price difference. The magnesium hydroxide product produced by the chemical synthesis method has better adaptability in the aspects of purity and appearance and better market prospect.
The chemical precipitation method for preparing magnesium hydroxide is classified into a sodium hydroxide method, a calcium hydroxide method, an ammonia method and the like according to different precipitants. When the reaction is carried out in the traditional batch stirring reactor, the concentration of reactants in a reaction system is constantly changed, so that the magnesium hydroxide prepared in the batch reactor is mostly in an amorphous sheet shape, and the quality of the magnesium hydroxide product is poor; when the precipitation reaction is carried out in a continuous stirring groove type reactor, because the retention time of materials in the reactor is short, magnesium hydroxide crystals generated by the reaction cannot be in time to form good appearance, the product quality is not good, and the magnesium hydroxide is difficult to directly use in many occasions. Therefore, the method and the device for preparing the magnesium hydroxide have the advantages that a reaction device and a process capable of realizing continuous production are found, the retention time of materials in a reactor can be prolonged, so that magnesium hydroxide crystals generated by the reaction have enough time to grow into products with good shapes, the adaptability of the products on different occasions is improved, and the method and the device for preparing the magnesium hydroxide have important significance.
The circulation reaction technology prolongs the retention time of the materials in the process, and has obvious strengthening effect on the rapid reaction process controlled by external diffusion and crystallization. In addition, because the horizontal circulating pipe type reactor is adopted to replace the traditional stirring reactor, no stirring paddle is arranged in the device, and the sealing is good. The horizontal circulating pipe type reactor is adopted, and the process is not easy to block through forced circulation, so that the production condition is greatly improved.
Disclosure of Invention
The invention aims to provide a continuous magnesium hydroxide production process based on a horizontal circulating tubular reactor.
The purpose of the invention is realized by the following technical scheme:
a magnesium hydroxide continuous production process based on a horizontal circulating tube type reactor comprises the process steps of solution preparation, reaction, aging, filtering and drying; the process runs continuously, a circulating pipe type reactor, a circulating pump and a circulating pipeline are adopted, and auxiliary equipment comprises a raw material storage tank, a pump, a flowmeter, a filter, an ageing tank and a dryer; the process reaction temperature is 20oC~200 oC(ii) a The concentration of the raw material magnesium salt is 0.1-2.5 mol/L, and the molar ratio of the precipitator to the raw material magnesium salt is 1-5 times of the stoichiometric value; the aging temperature is 50-200 ℃, and the aging time is 0-10 hours; the raw material magnesium salt is magnesium chloride or magnesium nitrate or magnesium sulfate magnesium salt; the precipitant is recycled or made into commodity for sale.
The continuous production process of the magnesium hydroxide based on the horizontal circulating tube type reactor is characterized in that the precipitator is lime, sodium hydroxide, ammonia water, ammonia gas or alkaline substances thereof.
The continuous production process of the magnesium hydroxide based on the horizontal circulating tube type reactor is characterized in that the circulating tube type reactor is a horizontal tube type reactor.
The continuous production process of the magnesium hydroxide based on the horizontal circulating tube type reactor is characterized in that the horizontal tube type reactor is a long straight pipeline or a spiral pipeline.
The invention has the advantages and effects that:
1. compared with the traditional stirring kettle, the magnesium hydroxide production process adopting the horizontal circulating tube type reactor omits the traditional stirring element, and the equipment has the advantages of good sealing performance, low noise, low manufacturing and maintenance cost and the like;
2. the reaction materials in the horizontal circulating pipe type reactor have longer retention time, and the technical process has the advantages of high raw material conversion rate, good product quality, large production capacity of the reactor and the like;
3. the horizontal circulating pipe type reactor is adopted, the proper operation concentration and speed are selected, the materials are not easy to precipitate in the reactor, the problem of pipeline blockage is avoided, and the operation is easier.
Drawings
FIG. 1 is a flow chart of the continuous production process of magnesium hydroxide according to the present invention; wherein the tubular reactor is a long straight pipeline.
Detailed Description
The present invention will be described in detail with reference to the embodiments shown in the drawings.
The process takes magnesium salt and a precipitator as raw materials, adopts a circulating tube reactor, and in the circulating tube reactor, the magnesium salt and the precipitator react at 50-200 ℃ to generate magnesium hydroxide precipitate, the obtained precipitate is aged at 50-200 ℃ for 0-10 hours, and then is filtered and dried to finally obtain a magnesium hydroxide product. The auxiliary equipment of the process comprises a raw material storage tank, a pump, a flowmeter, a filter, an ageing tank, a dryer and the like.
Example 1. magnesium chloride solution of 0.5mol/L and sodium hydroxide of 1mol/L are used as raw materials, equal volume is fed, a horizontal circulation tube type reactor is used for reaction, the reaction temperature is 90 ℃, continuous production is carried out, precipitates after reaction are filtered, aged for 4 hours at 100 ℃, and then the magnesium hydroxide product is obtained after filtering, washing and drying.
Embodiment 2. magnesium sulfate solution of 1.5mol/L and ammonia water of mass concentration 26% -28% are used as raw materials, feeding is carried out according to molar equivalent ratio, a horizontal circulating tube type reactor is adopted for reaction, the reaction temperature is 95 ℃, continuous production is carried out, precipitates after reaction are filtered, aging is carried out for 2 hours under the condition of 140 ℃, and then the magnesium hydroxide product is obtained after filtering, washing and drying.
Example 3 magnesium hydroxide product is obtained by using 1mol/L magnesium nitrate solution and ammonia gas as raw materials, feeding the raw materials according to a molar equivalent ratio, reacting the raw materials by using a horizontal circulating tube type reactor at the reaction temperature of 100 ℃, continuously producing the raw materials, filtering precipitates after the reaction, aging the precipitates for 2 hours at the temperature of 120 ℃, and filtering, washing and drying the precipitates.