关键词: 金属镁, 白云岩, 皮江法, 碳热还原法, 温室效应, 清洁生产

Abstract:

Dolomite and magnesite ores with high quality are both abundant in China, giving rise to an excellent resource background to develop magnesium smelting industry. At the end of the last century, China became the largest country in the world for the production and exportation of primary magnesium produced by the Pidgeon process, at the higher expense of energy and dolomite resource consumptions, and the local environmental quality. During the social and economic developments, China is currently facing the growing challenges in energy, mineral resources, and the environments. It is highly demands to develop magnesium smelting industry sustainable, instead of the Pidgeon process widely used nowadays. Using high quality dolomite ores as the raw materials, it is the optimal technical choice that primary magnesium is produced by the carbothermic reduction process with the developed procedure in this paper, i.e.,at the first, dolomite ore is calcined into dolomitic lime, and then, the magnesium oxide is separated from calcium oxide in the lime, and further, reduced by carbon to primary magnesium, while the calcium oxide is used to produce light-weight calcium carbonate as a coproduct. Compared with the Pidgeon process, the suggested technique has such advantages as a higher availability of dolomite resources, higher efficiency of energy consumptions, and completely clean processes.Under the current social and economic situations in China, this innovative technique system will definitely lead the magnesium smelting industry going forward to a sustainable development, and therefore, satisfying the requirements to develop the country with saving the mineral resource and the environmental kindness.  

Key words:  primary magnesium, dolomite, the Pidgeon process, the carbothermic process, warm house effect, clean processing