CN-117142500-B - Preparation method of high-quality magnesium oxide

Abstract

The invention provides a preparation method of high-quality magnesium oxide, and belongs to the technical field of magnesium metal oxide synthesis. The invention uses waste magnesium hydroxide generated in the ethyl maltol process as raw material, and obtains magnesium oxide through sodium hypochlorite oxidation, twice water washing and calcination, the obtained magnesium oxide has high purity and high activity, the method has the advantages of short process flow, low roasting temperature, less side reaction, less subsequent equipment investment, lower sodium hypochlorite price, cost saving, no introduction of new impurities and better industrial application value.

Inventors

• CHEN YUHAN
• SHEN DONGDONG
• WANG QUN
• QIU XIN
• WANG YUBIN
• CHEN YONGLE
• GONG XI
• QIN JINNENG
• QIN JILOU

Assignees

• 安徽金禾实业股份有限公司

Dates

Publication Date

20260508

Application Date

20230915

Claims (8)

1. 1. The preparation method of the high-quality magnesium oxide is characterized by comprising the following steps of: Grinding magnesium hydroxide waste, pulping by adding pure water, adding sodium hypochlorite for oxidation, and filtering to obtain a magnesium hydroxide crude product I, wherein the adding amount of the sodium hypochlorite is 5-25% of the mass of the magnesium hydroxide waste; Step two, washing the magnesium hydroxide crude product I with water, filtering to obtain a magnesium hydroxide crude product II, wherein the washing times are 2-3 times, the mass ratio of the magnesium hydroxide crude product I to water is 1:1-3 in the washing process, the washing time is 5-30min, and the temperature is 50-70 ℃; and thirdly, drying, grinding, sieving and calcining the magnesium hydroxide crude product II to obtain the magnesium oxide.
2. 2. The preparation method according to claim 1, wherein the magnesium hydroxide waste is a byproduct generated in the process of producing ethyl maltol from furfural, and the magnesium hydroxide waste comprises 69.85-89.98w/w% of magnesium hydroxide, 10-30w/w% of water, 0.01-0.1w/w% of 5-ethyl-2 (5H) -furanone and 0.01-0.05w/w% of furfural.
3. 3. The method according to claim 1, wherein in the first step, the mass ratio of the magnesium hydroxide waste to water is 1:1-3.
4. 4. The method according to claim 1, wherein in the first step, the beating condition is that the time is 5-10min and the temperature is 50-70 ℃.
5. 5. The method according to claim 1, wherein in the first step, the sodium hypochlorite is added in an amount of 10% of the mass of the magnesium hydroxide waste.
6. 6. The method according to claim 1, wherein in the third step, the drying temperature is 80-110 ℃ and the drying is carried out until the water content of the magnesium hydroxide crude product is 0.01-0.1%.
7. 7. The method according to claim 1, wherein in the third step, the number of the sieved mesh is 40 to 80.
8. 8. The method according to claim 1, wherein in the third step, the calcination is performed at a temperature of 800 to 1000 ℃ for a time of 0.5 to 3 hours.

Description

Preparation method of high-quality magnesium oxide Technical Field The invention belongs to the technical field of magnesium metal oxide synthesis, and particularly relates to a preparation method of high-quality magnesium oxide. Background Magnesia, also known as magnesite, magnesia, exists in periclase in free form in nature. Magnesium oxide is the core of magnesium compounds and is also the raw material for other high purity magnesium compounds. In recent years, the use of magnesium oxide has been continuously developed, and the use of magnesium oxide as a heat-resistant material, a high-temperature insulating material, a lighting material, cosmetics, paints, a catalyst, and the like has been continuously increasing, so that development and research of magnesium oxide of high quality have been demanded. The existing method for producing magnesium oxide mainly comprises calcining magnesium hydroxide or magnesite, and common methods for producing magnesium oxide by using magnesite mainly comprise carbonization method, acidolysis method, soda ash method and the like. The carbonization method is to calcine solid ore such as magnesite into powder for nitration, then carbonize, hydrolyze by heating to generate basic magnesium carbonate, and then dry and burn to obtain light magnesium oxide. The acidolysis method comprises acidolysis, calcination, calcium separation, acid dissolution, magnesium precipitation and burning, and has the advantages of more impurity ions, high acid consumption and high cost. The soda process is to react bittern with soda to produce basic magnesium carbonate precipitate, and to wash, dewater and calcine to obtain magnesia. The method has high cost, high energy consumption and complex production process. At present, many researches on producing magnesium oxide by using magnesite are carried out, and as disclosed in patent CN106745103A, a method for preparing magnesium oxide by using magnesite comprises the steps of calcining magnesite, adding the magnesite into ammonium salt solution for leaching, filtering to obtain magnesium salt leaching solution, then reacting with ammonia water to obtain magnesium hydroxide precipitate, and calcining to obtain magnesium oxide. Also as in patent CN113772970a, a method for preparing magnesium oxide from magnesite is disclosed, which comprises screening the flotation concentrate of magnesite into at least two kinds of ore powders, and respectively performing fluidized calcination to obtain magnesium oxide. And less research is being conducted on the production of magnesium oxide from strong magnesium oxide. The current industrial preparation process of magnesium oxide mainly comprises the steps of crushing a magnesium hydroxide filter cake, then burning organic matters in a rotary furnace at a high temperature of 1100 ℃, and roasting at 800 ℃ twice to obtain the magnesium oxide. The method is easy to carbonize organic matters to cause the blockage of pore channels, and the prepared magnesia has the advantages of more organic matters, poor quality, poor activity, huge energy consumption and higher cost. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a preparation method of high-quality magnesium oxide. The method takes the byproduct magnesium hydroxide waste material generated in the ethyl maltol process as a raw material, and utilizes sodium hypochlorite as an oxidant to oxidize the magnesium hydroxide to prepare the magnesium oxide, so that the obtained magnesium oxide has high purity and high activity, and the method has the advantages of short process flow, less side reaction, less subsequent equipment investment, lower sodium hypochlorite price, cost saving, no introduction of new impurities and good industrial application value. In order to achieve the above purpose, the present application adopts the following technical scheme: A method for preparing high-quality magnesium oxide, comprising the following steps: grinding magnesium hydroxide waste, adding pure water for pulping, adding sodium hypochlorite for oxidation, and filtering to obtain a magnesium hydroxide crude product I; step two, washing the magnesium hydroxide crude product I with water, and filtering to obtain a magnesium hydroxide crude product II; and thirdly, drying, grinding, sieving and calcining the magnesium hydroxide crude product II to obtain the magnesium oxide. Optionally, in the first step, the magnesium hydroxide waste is a byproduct generated in the process of producing ethyl maltol from furfural, wherein the magnesium hydroxide waste comprises 69.85-89.98% of magnesium hydroxide, 10-30% of water, 0.01-0.1% of 5-ethyl-2 (5H) -furanone and 0.01-0.05% of furfural. Optionally, in the first step, the mass ratio of the magnesium hydroxide waste to the water is 1:1-3, and preferably, the mass ratio of the magnesium hydroxide waste to the water is 1:3. Optionally, in the first step, the beating condition is that the time is 5-10min and