1. State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University, Xi’an 710049, China2. Engineering Research Center for Magnesium-Based New Materials, Xi’an Jiaotong University, Xi’an 710049, China3. School of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China4. Guoke Magnesium Technology(Henan) Co., Ltd., Luoyang 471000,China
The calcination of dolomite, as the first step of silicothermic reduction magnesium production, is not only the main step of energy consumption and carbon emission, but also the key influencing factor for the yield and quality of primary magnesium. At present, the mainstream calcining process of rotary kiln is faced with many problems, such as low thermal efficiency, high energy consumption, large pollution, low single-line production capacity and unstable product quality. The whole calcination process is in urgent need of technical innovation. In this paper, suspension calcining process is proposed to replace rotary kiln for dolomite calcination, and the two processes are compared comprehensively. The former shows remarkable technological, environmental and economic advantages: theoretically, the energy saving is more than 50%, the CO2 emission reduction is more than 20%, the production cost is reduced by 35% compared with the present, and can effectively avoid “overburning”and “underburning” to obtain high quality calcined products with stable performance for the subsequent magnesium smelting process. This paper also analyzes the feasibility of replacing the present “scattered” calcination with environment friendly and efficient integrated dolomite suspension calcination and its possible revolutionary influence on the whole magnesium industry.