中国金属镁工业的环境效应与可持续发展

中国的优质白云岩、菱镁矿资源丰富,为发展金属镁工业提供了良好条件。20世纪90年代末,以相对浪费能源、资源和牺牲区域环境质量为代价,依赖皮江法炼镁技术,中国发展成为世界上金属镁生产和出口的第一大国。现今中国社会和经济发展面临的能源、资源和环境挑战,决定了必须对皮江法炼镁技术进行变革,以实现金属镁工业的清洁生产和节约发展。以优质白云岩为原料,经煅烧和钙镁分离,生产轻质碳酸钙和氧化镁,进而采用碳热还原法提取金属镁的技术,较之传统的皮江法具有资源利用率高、节能高效、且可完全实现清洁生产等优势。这一创新技术体系,将在现今中国国情背景下,引导金属镁工业步入可持续发展之路,符合建立资源节约型、环境友好型国家的要求。

Environmental Impacts and Sustainable Developments of Magnesium Smelting Industry in China: A Review

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.