Magnesite-Metallurgical Auxiliary Raw Material Mineral
First, the nature of use
The chemical composition of magnesite is magnesium carbonate (MgCO3), in which magnesium oxide (MgO) content is 47.81%, carbon dioxide (CO2) content is 52.19%, and often contains a small amount of iron, manganese, aluminum and silicon, calcium and other impurities. The magnesite is heated to about 650 °C to start to decompose and release CO2, accompanied by volume shrinkage; when calcined to 700-1000 ° C, it forms caustic magnesite (light burned magnesite) and has a high degree of adhesiveness; When calcined to 1400-1700 °C, it decomposes completely, does not contain CO2, forms periclase (hard burned magnesite), and has high refractoriness.
Magnesite is mainly used (about 90%) as a refractory material. That is, using high-temperature calcined hard-fired magnesite to produce refractory products such as metallurgical magnesia, metallurgical powder, magnesia brick, magnesia chrome brick, magnesia-aluminum brick and silicon-magnesia brick with refractoriness above 2000 °C, used for masonry Black and non-ferrous metallurgical industry furnaces. When the hard-burned magnesite is calcined in an electric furnace to 2500-3000 °C, it is melted and cooled to form a complete periclase crystal called fused magnesium. It has high electrical resistivity, high hardness, chemical corrosion resistance, and can be used for insulation and advanced fire resistance. The material is made into a magnesium crucible and a refractory furnace.
Magnesite can be used to refine magnesium metal. Magnesium is combined with other metals to form high-strength magnesium alloys for military applications. Aerospace industry, and aircraft, automotive and precision instrument manufacturing. Magnesium is also used as a reducing agent for the smelting of titanium, zirconium, uranium and thorium.
Light burned magnesite and magnesia or magnesium sulfate can be used to make magnesium-containing cement, which is highly gelatinous, malleable and can be glued to organic matter. Used as a building material for decoration, insulation, insulation, sound insulation, wear resistance, and as a binder for making grinding wheels.
In addition, it is used in chemical, rubber, paper, ceramics, sugar, photography, pigments, and textile industries.
Second, general industrial requirements
(1) Industrial quality requirements for ore
In the industry, crystalline and cryptocrystalline magnesite can be used. The different requirements for ore quality depending on the application are as follows:
As hard-fired magnesite for refractory materials, crystalline magnesite with high MgO content and less impurities is required. The effect of impurities in the ore on the quality of the refractory is as follows:
CaO: When calcining magnesite, CaO is in a free state and easily absorbs water to form Ca(OH)2 or other compounds, which is harmful to the product. Generally, CaO ≤ 3% is required in the finished product.
SiO2: When the content of silicon oxide is high, the refractoriness of the product is lowered. Generally, SiO2 is limited to about 5% in the finished product.
Fe2O3: When the ore contains 3-5% Fe2O3, it is beneficial to roasting; however, the excess Fe2O3 easily forms a fusible substance with other impurities, which affects the refractoriness of the product.
2. For light-burning magnesite containing magnesium cement, crystalline or amorphous magnesite can be used, and its quality requirements are not strict; but when CaO is in a free state, the cement is expanded, so CaO is generally required. 4.5%; iron can make the cement color deteriorate not too high; SiO2 content 15-20% can also be applied.
3. Refining magnesium metal and other industrial magnesite, generally requires high MgO content and low impurity; magnesite in rubber industry should have high dispersibility and no manganese.
Overview
Magnesite is often associated with minerals such as dolomite, marble, serpentine, asbestos, talc, gypsum, salt mines, etc., especially magnesite produced in ultrabasic rock serpentine rocks, possibly accompanied by platinum, Minerals such as cobalt and nickel should be noted and comprehensively explored and comprehensively evaluated.
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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