Mobile phone: 13065499999
Address (Add): Nanzhao Tie Village, Pailou Town, Haicheng City, Liaoning Province
At present, the total output of sintered magnesia in China is 4 million to 4.5 million tons per year. Following the industry habit, lightly burned magnesia balls can be divided into heavy burned magnesia, medium-grade magnesia and high-purity magnesia. Before 1980's, the production of sintered magnesia in China was mainly undertaken by Dashiqiao magnesia mine of Anshan Iron and Steel Co. for more than 30 years. The shaft kilns with 25 cubic meters, 32 cubic meters, 40 cubic meters, 47 cubic meters and 55 cubic meters were successively adopted. With coke as fuel and magnesite as raw material, the magnesia with 92% MgO content was produced by one-step calcination and artificial discharging. Bricks are used as raw materials for open hearth steelmaking.
The disadvantages of this process are: low utilization ratio of ore and non-utilization of fine-grained ore; high impurity content and ash in Coke will pollute magnesia, which will increase the content of SiO 2 and AlO 3 of magnesia, and the maximum content of MgO can only be guaranteed at 92%; poor continuous operability, the thermal decomposition of large magnesite produces small-grained ore adhering to the kiln wall, and the material in the kiln is prone to "agglomeration". The frequent changes of material flow and thermal system in the kiln result in the failure of mechanized operation, the low density of magnesia, the decomposition of magnesite in the kiln pretropical zone, the release of CO2 into light burning MgO, but the "mother salt" illusion of MgCO3 still exists, which is not conducive to the further densification of magnesia, and the volume density of sintered magnesia is only between 3.0 g and 3.1 g per cubic centimeter. The environment is serious, magnesite decomposes a lot of CO2 and burning flue gas mixed with fine coke particles and light burning dust flying out of the kiln, which pollutes the environment and makes it difficult to control high temperature flue gas. At present, secondary and tertiary magnesia ores are still calcined in solid fuel shaft kilns in China. Magnesium content of magnesia is 90%~92%, volume density is more than 3.10 grams per cubic centimeter. Reburnt magnesia is the main raw material for the production of ordinary magnesia fired bricks and amorphous refractories. The annual output of Liaoning Province is estimated at 2.5 million tons at present. Due to the use of tertiary minerals, the product price is low and has a market, it is difficult to be eliminated at present. Medium grade magnesia. In order to improve the density and purity of magnesia, two-step calcination process research and industrial test of magnesia have been carried out in refractory industry in China. The new technology and process suitable for the national conditions have promoted the technological progress of sintered magnesia production. In the early 1980s, Haicheng Magnesium Mine produced medium-grade magnesia with MgO content (>95%) and bulk density (>3.20 grams per cubic centimeter) by light burning of high-quality magnesite ore in a reflex furnace, fine grinding by Raymond mill, semi-dry two-stage balling and calcination in a coke shaft kiln. This achievement has been rapidly promoted, resulting in an annual output of hundreds of thousands of tons of scale benefits. Thereafter, the process was popularized to produce synthetic magnesia-calcium sand and other synthetic sand products.