Magnesite deposits occur in the pre-Sinian Liaohe Dashiqiao dolomite marble, and the ore bodies of the layer-deposited metamorphic magnesite deposits are mostly layered or lens-like. The deposits are large in scale and the thickness of the deposit is more than ten to dozens of meters. , The main mineral is magnesite, the impurity mineral is talc, and the secondary mineral is dolomite. Magnesite is an important alkaline refractory raw material. At present, China has more than 27 proven magnesite origins, with a total proven reserves of more than 3.402 billion tons, accounting for about a quarter of the world's proven reserves. The origins are mainly concentrated in Liaoning Dashiqiao-Haicheng-Xiuyan area, as well as Ye County in Shandong, Biegai in Gansu, Xingtai in Hebei and Ganluo in Sichuan. The province’s proven reserves in Liaoning are 2.577 billion tons, accounting for 85% of the country’s total reserves and about one-fifth of the world’s total reserves. In 1913, the Wangjiabaozi, Jinjiapuzi and Xiafangshen magnesites in the Liaodong Peninsula were discovered. Later, magnesites in the Haicheng and Yingkou areas were also discovered. As early as the Japanese puppet period, Dashiqiao magnesite was mined, and a certain scale was formed in the 1950s. With the construction of the Anshan Iron and Steel Dashiqiao Magnesium Mine in 1954, the mining volume of the Dashiqiao Magnesite Mine increased greatly, and the scale gradually expanded in the 1960s; before 1990, there were no more than 10 magnesite mines, and after 1990, it rapidly increased to In 2004, there were more than 200 mines. Anshan Coking Refractory Design and Research Institute and Angang Refractory Factory cooperated to systematically study the basic properties and brick making process of magnesite in Liaoning. Luoyang Refractory Research Institute and other systems have systematically studied the basic properties and brick making of Shandong Yexian (high silicon) magnesite, Gansu Biegai (high aluminum) magnesite, Hebei Xingtai (high silicon) magnesite and Sichuan Ganluo magnesite Process, and put forward suggestions on magnesite classification. The Ministry of Metallurgy promulgated the standard refractory magnesite in 1981 to replace the technical conditions YB321-65 established in 1965, see Table as below:
Note: (1) The tertiary product for the production of magnesia silica sand, where SiO2 can be ≤ 4% (w);
(2) Three grades selected for heating, of which SiO2 can be ≤5% (w);
(3) Product size. 25~100 mm, less than 15%(w) of <25 mm, not more than 10%(w) of >100 mm, the maximum is not more than 120 mm; 0~40mm, no more than 10%(w) greater than 40 mm, and a maximum of 60 mm.
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Item
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Chemical composition (w)/%
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MgO
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CaO
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SiO2
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Premium product (LMT-47)
First class product (LM-46)
Second grade (LM-45)
Third grade (LM-44)
Fourth grade product (LM-41)
Magnesite powder (LMF-33)
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≥47
≥46
≥45
≥43
≥41
≥33
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≤0.6
≤0.8
≤1.5
≤1.5
≤6.0
≤6.0
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≤0.6
≤1.2
≤1.5
≤3.5
≤2.0
≤4.0
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