How much do you know about fused magnesia calcium sand refractory raw materials?

Resource and mining of raw material of fused magnesia-calcium sand

Magnesium raw materials refer to magnesium-containing minerals that can be used to produce magnesia refractories, magnesia chemical materials, metal magnesium and other products. The price of magnesia-calcium sand is mainly divided into solid minerals such as magnesite, dolomite, brucite, etc. and liquid Minerals such as sea water, salt lake brine, etc. Magnesite is one of the most important refractory raw materials in the world. It is mainly used for calcining light-burned magnesia (CCM), sintered magnesia (DBM), fused magnesia (FM) and other refractory raw materials. base material.

my country is one of the countries with the most abundant magnesite resources in the world. Magnesium-aluminum spinel is mainly distributed in Liaoning and Shandong provinces, and concentrated in Liaoning Province. At present, the magnesite reserves that have been identified in Liaoning Province are 3.413 billion tons, accounting for about 85% of the country and 20% of the world. Liaoning magnesite reserves, mining volume, as well as magnesia refractory production and export volume rank first in the world. At present, there are 12 mining areas in Liaoning that have undergone geological exploration, and about 16 million tons of special, first, second and third grade ores with MgO content ≥ 44% are mined annually, mainly for production enterprises in the province. Liaoning magnesite is a crystalline ore with large crystal particles and difficult to sinter. The industry standard YB/T 5208-2004 formulated the standard of natural magnesite with MgO content of 33%~47%.

Main products and status quo of fused magnesia-calcium sand refractory raw materials

Magnesium Aluminum Spinel

Lightly burn magnesia. At present, magnesite is used as raw material in my country, and it is processed into light-burned magnesia powder (CCM) through reverberatory furnace light burning, which is large in quantity and widely used. Light-burned magnesia powder is a very important basic raw material of magnesia. According to its different chemical composition, particle size and properties, it is applied to: sintered magnesia (DBM) of various grades by ball pressing, which is different from Al2O3, CaO, etc. The composite materials such as magnesia-aluminum spinel sand, magnesia-calcium sand, etc. are synthesized from raw materials with high content, to produce fused magnesia (FM, refractory grade or electrical grade), converter slag splashing protection magnesia ball, etc. The above products are mainly used as raw materials for refractory products. In addition, these products are also raw materials for magnesium chemical products such as light MgO, light MgCO3, magnesium fertilizer, magnesium building materials, feed additives, etc.

Traditional light-burned magnesia is processed by roasting raw ore in a reverberatory furnace. The use of reverberatory furnace to produce light-burning magnesia has not been eliminated after 70 to 80 years of survival and development, because the furnace has its outstanding characteristics: simple and practical process; less investment, quick start, easy operation; suitable for southern Liaoning area Magnesite features. In the past ten years, the kiln-type production process has also been greatly improved, mainly in: switching to clean fuel, and changing the original direct burning of bituminous coal to the gas produced by a simple gas generator for roasting, so as to avoid fuel ash. Light-burning magnesia pollution basically solves the environmental pollution caused by black smoke emissions and improves thermal efficiency; the kiln type is modified to increase the volume of the kiln, increase the output, and reduce the unit consumption of fuel.

However, there are still the following problems in the production of light-burned magnesia powder by roasting magnesite in a reverberatory furnace in my country: simple mining activities and manual mining; manual operation of the kiln, poor kiln temperature stability and high energy consumption; The crushed ore is discarded, and the material consumption is high; the flue gas is not treated, which pollutes the environment; the cooling is open, and the working conditions are poor, which makes it difficult to recruit workers; the grinding equipment is backward, the particle size control is poor, and the final product quality is low and fluctuates greatly.