Magnesite beneficiation can only remove SiO2. If high purity is pursued, only ore with very low Fe2O3, Al2O3 and CaO can be selected to remove SiO2 to achieve the goal. If the comprehensive utilization of resources is considered and the grade is improved, only high-silica flotation can be selected. Dead burnt magnesia
The higher the purity of high-purity magnesia, the less binding phase, the more unstable it is, and it is not necessarily suitable for refractory materials.
High-purity magnesia from the perspective of market demand
What is the market demand for magnesia with MgO ≥ 98%? The variety structure of refractory raw materials should conform to the demand structure of the raw material market. In terms of the demand for steelmaking converters, high-purity magnesium with MgO ≥ 98% should be used except for the trunnions and slag lines on both sides of the converter. Outside of sand-produced products. Refractory products produced by high-purity magnesia are not required in other areas.
Dead burnt magnesia
Magnesite is a general term for the products that are processed by one-step calcination or two-step calcining process to reach the sintering degree of magnesia raw materials such as magnesite such as shaft kiln and rotary kiln. There are different classifications of magnesia, among which magnesia fired from natural magnesite is called sintered magnesia; magnesite is smelted by electric arc furnace as raw material to reach a molten state and formed after cooling is called fused magnesia. ; It is called seawater magnesia made by extracting magnesia from seawater.
Seawater magnesia and sintered magnesia. Foreign high-purity magnesia has advanced production technology and high purity, but due to higher production costs, it has not formed an overall advantage.
The high-purity magnesia market is operating stably, the downstream demand has not changed for the time being, and the quotations of manufacturers also continue to remain stable.
Magnesia can be divided into two categories: natural magnesia and seawater magnesia or synthetic magnesia. Natural magnesia mainly comes from natural magnesite, but it is difficult to obtain high-purity products due to the limitation of raw ore quality. So far, seawater magnesia has become the main source of magnesia used in industrialized countries. The theoretical content of MgO in magnesite is 47.3%, and the remaining impurities are CaO, SiO2, iron and so on.