There are four ways to produce light-burned magnesia powder: light-burned magnesia powder, light-burned magnesia powder, light-burned magnesia powder, light-burned magnesia powder, light-burned magnesia powder and light-burned magnesia powder
1. Gas-phase Light Burning Powder Products
The high purity magnesium metal reacts with oxygen to form crystal nuclei, and then the particles continue to grow to produce high purity light burnt powder. Crude raw materials containing more than 80% magnesium oxide (by weight) are dissolved with inorganic acids (sulfuric acid, hydrochloric acid, nitric acid) in a molar ratio of 1:2 to form magnesium salts of inorganic acids. The impurities were removed by refining, heated under pressure in oxygen atmosphere, then washed, dehydrated and dried, and heated at 1100 C for 1 hour to produce high purity light burning powder.
2. Satin firing
Magnesium hydroxide calcination
Magnesium (OH) 2 was precipitated from purified magnesium sulfate solution by adding pure ammonia water as precipitant. The cake was washed to obtain high purity Mg (OH) 2 by plate and frame filter press, and then dried and forged to produce high purity light burning powder.
Bitter soil powder calcination method
Bitter soil powder is washed by water, impurities are removed and precipitated into magnesium slurry. Then magnesium hydroxide is dehydrated to form light burning powder by digestion, drying and calcination.
Satin firing of magnesite
The magnesite was calcined in a forging furnace at 950 C, then cooled, screened and crushed to produce light burning powder.
Dolomite forging method
Active light-burning powder can be prepared from dolomite by calcination, digestion with water, carbonation, calcination and crushing.
3. Soda-soda process
First, bittern was diluted to about 20 degrees and added to the reactor. Under stirring, the clarification solution of soda at about 20 degrees was slowly added to react at about 55 degrees. Heavy magnesium carbonate was formed. After washing and centrifugal separation, it was roasted at 700-900 degrees. After crushing and air separation, light-weight and light-weight roasted powder was prepared.
4. Hydrochloric acid method
Magnesium chloride hexahydrate was formed by adding hydrochloric acid to react with the waste material of producing heavy magnesium oxide. Then sodium carbonate was added to react to form basic magnesium carbonate. After washing with water, basic magnesium carbonate was calcined at high temperature and crushed after cooling to produce magnetic light burning powder.
Light Burning Powder Products
The so-called pre-homogenization of light-burned magnesia powder refers to the uniform dispersion of MgO content and active MgO content in light-burned magnesia powder, and the uniform composition and quality stability of light-burned magnesia powder are achieved through certain mechanical equipment treatment.
Firstly, it is well known that when calcining magnesite in a reflective kiln, because of the different size of the block, in a limited calcination time (2-3h), coupled with the fluctuation of calcination temperature, magnesite will inevitably produce Underburning and overburning, so the composition of the lightly calcined powder will not be the same.
Secondly, most of the ore resources are not mined by zoning or collocation in the light-burning magnesia plant, resulting in fluctuation of ore composition. The magnesia content and active magnesia content in the calcined light-burning powder fluctuate greatly, resulting in inconsistency of composition.
Thirdly, most light burning powder manufacturers, after the satin burning of magnesite ore, do not have enough time to ripen the oven, and directly carry out Raymond grinding powder, then directly pack, which also results in inconsistent composition of light burning powder.
The quality and composition of light-burning powder used in magnesite industry today are not only different from different manufacturers, but also different batches of the same manufacturer or even the same batch of products. As a result, the quality of magnesia oxychloride products produced by the same manufacturer is very unstable. Especially if the content of light-burning powder is not continuously detected, it will inevitably lead to the excess or deficiency of coagulation coordinator MgCI2. It will inevitably lead to brine return and frost spread of magnesium oxychloride products. Therefore, the quality stability of light burning powder is the key to affect the quality of magnesium oxychloride products, and also the bottleneck of the development of magnesite industry.
Pre-homogenization of light-burning powder is an important means to stabilize the composition and quality of light-burning powder.