Thermal Decomposition Kinetics of Siderite Ore during Magnetization Roasting

The non-isothermal magnetization roasting process and isothermal magnetization roasting process of siderite ore were investigated using thermogravimetric (TG) analysis and a real-time infrared gas analyzer. X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) were used to analyze the characteristics of samples. The results showed that the decomposition degree and decomposition rate of siderite ore were vitally affected by heating rate and roasting temperature. It was determined that A(1) reaction model (f(alpha) = 1 - alpha) and A(3/2) reaction model (f(alpha) = (3/2)(1 - alpha)[-ln(1 - alpha)](1/2)) were the most probable mechanism function of the non-isothermal decomposition process and isothermal decomposition process, respectively. The phase transformation and decomposition mechanism during the roasting process were evaluated. Siderite decomposed in the process of magnetization roasting, released CO and CO2, and transformed into strongly magnetic magnetite. The SEM images highlighted that as the decomposition progressed, the structure of roasted samples was destroyed, and an increasing number of cracks and pores emerged on the surface, which is advantageous to the following grinding process.

Automated summary

Through experimental analysis, it was found that the heating rate and roasting temperature play a crucial role in the magnetization roasting process of siderite ore, and the most probable reaction models were determined. Phase transformation and decomposition occurred during the roasting process, ultimately transforming siderite into strongly magnetic magnetite.