Magnesia manufacture

According to the different sintering characteristics of raw materials and technical requirements of magnesia products, one-step or two-step sintering process can be adopted in magnesia production process. For the refractory raw materials, a two-step calcination process is used to produce high purity and high density magnesia with direct bonding between the main crystalline phases.

The one-step calcination process is as follows: raw material (magnesite with certain particle size requirements) calcination (coke or ashless fuel is used in shaft kiln or rotary kiln, calcination temperature is above 1600 final product inspection sintered magnesia. Because of SiO2 pollution in coke ash, SiO2 content in magnesia increased by about 2%.

The two-step calcination process is as follows: raw material (magnesite ore or refined concentrate powder with a certain size requirement) light calcination (in rotary kiln, Suspension Calcination kiln, multi-layer furnace, fluidized bed furnace or reverberatory furnace, using ashless fuel at about 1000 grinding (the finer the density of magnesia is higher) calcination (in shaft kiln or rotary kiln). Calcined with ashless fuel, temperature above 1800 C) to sintering magnesia.