Thermodynamic Study On Solid Phase Decarbonization Of High Carbon Ferromanganese Powder In Microwave Fluidized Bed

With the rapid development of Cr-Mn stainless steel and low carbon alloy steel, the decarbonization of high carbon ferromanganese is increasingly subjected to special concern in metallurgy industry. At present, the decarbonization of ferromanganese is basically carried out in the liquid phase, but the vapor pressure of manganese is relatively high, and the binding energy of manganese and oxygen is relatively large, and the volatilization loss and oxidation of manganese are serious, and the recovery rate of manganese is relatively low, so that the liquid phase decarbonization of manganese are seriously affected. The solid phase decarbonization of high carbon ferromanganese has been the research hotspot because of avoiding evaporation loss of manganese at high temperature.Microwave fluidized bed is a new type of fluidized bed, which is a combination of microwave heating characteristics and the characteristics of fluidized bed. Microwave can quickly heat high carbon ferromanganese powder without contacting materials, which is free from external contamination for materials. High carbon ferromanganese powder in the fluid state heated, that has good heat and mass transfer between materials and gas, to a great extent, which improves the decarbonization kinetics of high carbon ferromanganese and contributes to rapid decarbonization of high carbon ferromanganese.The study on solid phase decarbonization of high carbon ferromanganese powder is the most important study on thermodynamic analysis of solid phase decarburization. In this paper, O₂,CO₂,water vapor is the decarbonization agent. The thermodynamic relation between high carbon ferromanganese and gas decarbonization agent is studied. The results show that using O₂ as decarbonization agent, ferromanganese carbide is easy to be decarburized,but because of great oxidation of O₂, metal Mn and metal Fe is also easy to be oxidized to generate manganese oxide and iron oxide; using CO₂ as decarbonization agent, Fe3C is decarburized to generate metal Fe when the temperature was above 925K, and manganese carbide is decarburized to generate metal Mn when the temperature was above 1226K; using water vapor as decarbonization agent, Fe3C is decarburized to generate metal Fe when the temperature was above 905K, and manganese carbide is decarburized to generate metal Mn when the temperature was above 1312K. The external carbon of high carbon ferromanganese can be decarburized by O₂, CO₂ or H2O vapor. The surface of the metal manganese particles is oxidized easily by O₂, CO₂ or H2O vapor, so the gas - solid phase decarburization reaction between the carbide and decarbonization agent changes into the solid - solid phase reaction between superficial manganese oxide and internal manganese carbide to make high carbon ferromanganese decarburize.The cold fluidized test is carried out for high carbon ferromanganese of different weight and different size. The results show that the appropriate fluidized size of high carbon ferromanganese powder is -100⁺150 mesh and -150⁺200 mesh, and the appropriate fluidized weight is 500 g, and the best air flow is 0.4 0.8 m3/h.