Research Of Technology Condition Influence To Magnesium Metallurgy Reaction Process And Application

Currently most of magnesium manufacturers in China are using ferrosilicon thermal reduction method(Pidgeon process) as production process. Pidgeon process has advantages, such as low cost and stable products quality, however the disadvantage is also obvious, such as low heat efficiency, non-continuous production and serious pollution. Recently the demand of magnesium is saturated, however the yield of magnesium in China is still increasing, and the price of magnesium keeps falling. Therefore, seeking an improvement combining with actual production situation in China to increase the production efficiency is the key to save cost and improve the competitiveness of manufacturers.The research of carbon-based additives to improve reduction production process is proceeded under laboratory condition after investigate production line condition of a magnesium company in Yulin. Based on orthogonal experiment and verification experiment, the influence of additives with different parameters(component, particle size, additive amount and reaction duration) on reaction efficiency are researched. The dynamic mechanism of carbon-based additives improves reaction efficiency is proposed and verified. Three improvement schemes are proposed and cost of these three schemes are estimated. Combined with actual manufacture condition, the optimal scheme is obtained.The research shows: Carbon-based additives improved the efficiency of ferrosilicon thermal reduction reaction. Additive amount, particle size of additives and starting time of the vacuum system has influence to the reduction rate. Graphite powder has stronger improvement to reaction efficiency than semi coke, which means carbon exist in the form of element has stronger improvement to reaction efficiency. Carbon can be oxidized before the reduction reaction and exothermic, which can improve the thermal conductivity of the pellet. Besides, pellet become loose after carbon is oxidized, which can improve the diffusion of reaction product. Carbon can also participate in reduction reaction, which can push the reaction equilibrium.The optimal scheme to the magnesium company in Yulin is: using semi coke as additive with 8% mass ratio. Particle size of the additive should be smaller than 74?m. Vacuum system should be started 30 minutes after pellets is loaded in reaction tank. This scheme could save cost 1401 Yuan per ton of magnesium to manufacturer.