Application of brucite

1. Application in paper industry
Brucite has the characteristics of high whiteness, good flaking, strong adhesion, and basically no water absorption. The former Soviet Union used it together with calcite as the filler for paper making, which changed the acid method to the alkali method, and reduced the pollution of pulp water. In the paper industry, brucite replaces lime in the production of magnesium based sulfite pulp, which can absorb and make waste pulp water recyclable, greatly reducing the pollution of waste pulp water to the environment. As brucite does not absorb water in the air, it can also be used as a filler for moisture-proof packaging paper.
2. Application in fire and flame retardant materials
The natural brucite mineral is superfine crushed and surface treated to prepare a halogen-free and non-toxic Mg (OH) 2 flame retardant. When used, it is non-toxic and harmless, just like the decomposition products of the synthetic Mg (OH) 2 flame retardant itself, and is an environment-friendly flame retardant. Mg (OH) 2 flame retardant is produced from brucite. Natural minerals are used at the source, and the whole processing process is basically zero emission. It can be said that both the source and the product meet the requirements of green, so the development potential is huge.
The research and application results in recent years show that when the filling amount of brucite flame retardant is more than 40 phr, the composite can be used as a flame retardant material, and has good smoke suppression performance, without causing secondary pollution. With the increase of the amount of brucite flame retardant, the amount of carbon residue increases, and the combustion performance of the material decreases. when the filling amount reaches 60 phr, the brucite resin composite can be used as a fire-retardant material.
However, a large amount of brucite will reduce the mechanical properties of the resin composites. In order to meet the requirements of flame retardancy without reducing the mechanical properties of the material, measures such as ultra-fine particle size, fibrous brucite, surface treatment, addition of elastomer or graft compatibilizer, grafting of matrix resin or formation of cross-linked network structure can be taken.
Japan has developed a coating, which is made of cement, brucite and some other substances in proper proportion. This kind of coating has the characteristics of light volume weight, good decoration, strong weathering resistance, good fire resistance, and no peeling after fire. It can be used for surface coating of ships, high-grade residences, etc.
3. Preparation of magnesium chloride and magnesium oxide
Anhydrous magnesium chloride is the main raw material for electrolytic preparation of metallic magnesium. At present, magnesium chloride is mainly prepared by carbochlorination of magnesite particles in our country. At the same time, in order to supplement the lost chlorine, it is prepared by dehydration of carnallite.
The content of magnesium oxide in brucite is high, which can be directly calcined to produce magnesium oxide, and the process is simple, the cost is low, and it is easy to control. As a kind of refractory, brucite has been greatly developed abroad. Magnesite and dolomite are calcined into magnesium and calcium oxides at high temperature, and then finely ground, mixed with organic adhesives, pressed into molds, and calcined twice to produce refractory bricks. High grade magnesia can also be produced by using brucite.
4. Application in the field of environmental protection
Due to the characteristics of brucite, it can be used as a neutralizing agent for acidic wastewater. It not only has technological advantages over traditional alkali substances (such as calcium hydroxide, sodium hydroxide, etc.) in many aspects, but also can greatly reduce the cost of product treatment and emission. Brucite has a great demand in treating acid rain polluted soil, adjusting soil pH value and neutralizing acid wastewater. Brucite can also be used as flue gas desulfurization agent. Brucite added to boiler fuel can reduce the harm of high mercury and high sulfur fuel to the boiler and reduce the emission of sulfur dioxide and other harmful gases. Deep processing brucite into a non settling and non condensing active magnesium hydroxide can effectively be widely used in the field of flue gas desulfurization.
5. Applications in other fields
In addition to the above purposes, brucite can be electromelted to produce extremely dense periclase aggregates with high thermal conductivity and electrical insulation, and its service life is 2-3 times longer than that of smelting magnesite; If brucite and dolomite are calcined, their products can be used in iron and steel manufacturing industry to remove impurities such as P and S and treat slag; The mixture of brucite and calcium carbonate calcined at 800~1150 ℃ can be used in sugar industry to treat beet juice as a decolorant.
In China, brucite is rich in mineral resources, and its application field is also relatively wide. Therefore, the application of brucite in China has technical and economic advantages and environmental advantages, and brucite products have broad prospects in the international market. It is very meaningful to deeply study and explore the application technology of brucite production and processing machine.