Magnesium oxide is an inorganic substance with the chemical formula MgO, which is an oxide of magnesium. The production method of magnesium oxide mainly adopts the magnesite calcination method. 

Raw Material:

The calcination of magnesite to produce magnesia requires MgO>45%, SiO2<1.2 and CaO<1.5% for the ores used for calcination. The essence of magnesite calcination is the decomposition of carbonate: MgCO;=MgO+CO2.

① Light Burnt Magnesium Oxide

When magnesite is heated to above 640°C, it begins to decompose into magnesium oxide and carbon dioxide. When calcined at 100~1000C, carbon dioxide does not completely escape. The product is a powdery substance called light burnt magnesia (also called caustic magnesium, calcined magnesium, a.-magnesium). Its chemical activity is very strong, has a high degree of adhesiveness, easy to react with water to generate magnesium hydroxide.

② Dead Burned Magnesium Oxide

When calcined at 1400~1800°C, carbon dioxide completely escapes. Due to the occurrence of recrystallization and sintering, magnesium oxide forms a dense mass of periclase, which is called dead burned magnesia (hard burned magnesia, dead burned magnesia, β-magnesium) , This kind of heavy burned magnesia has high refractoriness.

③ Re-burned Magnesia

Re-burned magnesia is melted at 2500~3000°C, and after cooling and solidification, it develops into a perfect periclase crystal, called fused magnesia, called fused magnesia or molten magnesia. High-temperature calcined magnesia is not easy to mix with water Combination of carbonic acid has the characteristics of high hardness, strong chemical resistance and high resistivity.

Because these calcined products of magnesite have different chemical properties and characteristics, their uses are different. At present, the main production of sintered magnesia in China is shaft kiln, shaft kiln, rotary kiln and tunnel kiln can be used to produce light burned magnesia, and the main production equipment for electric melting is electric magnesia furnace.

Henan Zhengzhou Mining Machinery Co., Ltd. has rich experience in magnesite calcination projects, providing customers with a complete set of solutions. The process flow mainly includes raw material storage, magnesite calcination, grinding and pressing, reduction and refining, etc..

①The magnesite is crushed in the mine to meet the required particle size, and then stored in the magnesite yard in the plant. Ferrosilicon and fluorite are directly stored in the warehouse in the factory. The reserves are all considered based on the amount required for production in half a month.

②Qualified magnesite is sent to the rotary kiln for calcination; then the calcined magnesite, fluorite, and ferrosilicon are mixed in a certain proportion, and then ball milled and pressed into pellets; put into the reduction tank under vacuum conditions Next, high-temperature thermal reduction is performed to obtain crystalline magnesium; the crystalline magnesium can be remelted and refined to obtain metallic magnesium. Including raw material storage, magnesite calcination, grinding and ball pressing, reduction and refining, etc.

③Use energy-saving and environmentally friendly rotary kiln with vertical preheater and vertical cooler. The external magnesite whose particle size and quality meet the requirements is unloaded to the stockyard, where the loader performs stacking and reclaiming operations, and after screening by the vibrating screen, the magnesite with a particle size of 10 to 40 mm is transported to the rotary kiln vertical pre-treatment plant via a belt. The silo on the top of the heater enters the preheater through the material pipe and exchanges heat with the high-temperature flue gas flowing in from the rotary kiln. The material is preheated to above 800℃, and after falling into the transfer chute, it enters the rotary kiln and is calcined at 1250℃to become active calcining. The white is then discharged into the cooler, where the high-temperature calcined white exchanges heat with the cold air blown by the fan, and the active calcined white is cooled to below 100°C, and the air is preheated to above 600°C. After cooling, the activated calcined white is discharged from the cooler and transported to the ball making workshop by the scale conveyor.