Magnesite - Mineral Nature
Magnesite is the mineral name of magnesium carbonate. It is a natural alkaline mineral raw material with magnesium carbonate as its main component. Industrially used magnesite is actually processed magnesite, processed magnesite product, usually magnesite. Magnesite has two major categories of crystalline magnesite and amorphous magnesite.
China's magnesite is rich in resources, widely distributed, high in quality and large in reserves. The crystalline magnesite is mainly located in the Dashiqiao-Haicheng area of Yingkou, Liaoning Province, and its reserves account for 80% of the country.
Magnesite is mainly used for sintering magnesia, capacitor magnesia and the main raw materials for the production of alkaline refractories.
1. Crystal structure and properties of magnesite
Magnesite is a common carbonate mineral, together with anhydrous carbonate minerals such as calcite and dolomite, and is collectively referred to as calcite family minerals in mineralogy. The crystal structure of the calcite family minerals is similar, the cation radius is similar, and it can form a wide range of similar images, similar in physical properties, often closely symbiotic and mixed together.
2. The chemical composition of magnesite
The main chemical component of crystalline magnesite ore is magnesia, and the minor components are calcium oxide, silicon oxide, ferric oxide, and aluminum oxide. The content of magnesium oxide is generally 35% to 47%, the calcium oxide is 0.2% to 4%, the silicon oxide is 0.2% to 8%, and the content of ferric oxide and aluminum oxide is generally less than 1%. There are more than 20 types of trace elements such as P, Mn, Ti, Cr, and Ni, but there are many types, but there is no economic value.
The content of chemical components such as magnesium oxide, calcium oxide and silicon dioxide in the ore is determined by the mineral composition in the ore. The amount of magnesite in the mineral determines the level of magnesium oxide. The content of calcium oxide in the ore is determined by dolomite, and the content of silica is determined by talc, chlorite, quartz, and the like. When dolomite increases in the ore, the calcium oxide increases and the magnesium oxide decreases.
3. Mineral composition of magnesite ore
The mineral composition of crystalline magnesite ore, mainly magnesite, has a small amount of dolomite, and the altered minerals are mainly minerals such as magnesium-containing talc, magnesium chlorite, and sepiolite tremolite.
4. Physical and chemical changes in magnesite calcination
The chemical composition of magnesite ore, in addition to magnesium oxide, contains impurities such as ferric oxide, aluminum oxide, silicon oxide, calcium oxide, etc., and the basic physical and chemical changes that occur during calcination: one is the decomposition of magnesite, The crystal growth of the magnesite crystals; the second is the interaction of the impurity oxides or the impurity oxides with the magnesium oxide to form new minerals under high temperature.
The changes in the magnesite calcination process can be summarized as follows:
(1) cracks appear in crystallites of magnesite at 500 °C;
(2) The homogenized magnesia around the magnesite particles at 550 °C penetrates into the interior of the magnesite grains;
(3) Magnesite disappeared at 650 °C, and magnesium oxide showed partial heterogeneity;
(4) At 1100 ° C, tiny magnesia inclusions are formed in the periclase, and the color thereof is thus brown. The temperature continues to rise to 1400 ° C, no change is seen, but the magnesia brown is deepened.
FENGCHENG CITY HEQI BRUCITE MINING CO., LTD is registered in Dandong city, Liaoning province. Sufficient talent reserves, proper environmental governance, convenient transportation and communication.We are mainly engaged in the purchase, processing and sales of mineral products.
Main products: magnesium hydroxide flame retardant and brucite powder. Complete specifications of products, welcome to visit our factory guidance.
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