Fluidization and Magnetization Roasting Technology Research on Siderite

A research-scale fluidization and magnetization roasting device was developed to evaluate a processing option that might offset the complexity and high cost of the conventional magnetization roasting process on siderite. In this study, the operating parameters of the fluidization and magnetization roasting device for siderite were evaluated through cold-flow tests and magnetization roasting tests. The reaction mechanism functions of the fluidized roasting process were revealed with kinetic studies. The siderite ore sample used for this study was from Dechang, Sichuan, China, purified by low intensity magnetic separation and high intensity magnetic separation after crushing and grinding. The results indicated that a size fraction of -0.3mm of siderite was most suitable for fluidization and magnetization roasting, with a chosen gas velocity of 0.25 m/s as the best operating rate. Additionally, the findings showed that with increasing time and temperature, the majority of siderite converted into magnetite and at a temperature of 750 °C, conversion could be achieved in about 1 minute. However, at this temperature, the formation of FeO was noted, which could be detrimental to the process. Overall, diffusion was determined to be the controlling factor for the chemical reactions during fluidization and magnetization roasting.