Research, development and application of compound-vertical-retort technology for magnesium production

This paper comprehensively introduces a new magnesium production technology the compound-vertical-retort technology, involving in the related fundamental researches, core equipment development, working flow, and technical characteristics. Scale-up test and an annual 1200-ton-magnesium demonstration-level test was conducted to confirm the rationality, reliability, and advancement of the equipment, system and process design. It is indicated that the new technology solved a series of problems of traditional silicothermic process including adhesion and glaze, short life of retort, low efficiency, high impurity of crystallized magnesium, large heat losses, and poor working environment, making a great technological breakthrough in this field. Representatively, the new well-designed ceramic-lined steel retort serves 2∼3 times in life than the normal retorts. The magnesium yield per retort is improved 4∼5 times, with purity of >99.8%. The energy consumption in reduction stage is reduced by more than 20%. The mechanical production is fully realized and operating environment is significantly improved.