Mineral Raw Material Roasting

Mineral raw material roasting is a technological process of physical and chemical changes of the minerals in the target component of the mineral raw material at a suitable atmosphere and a temperature below the melting point of the mineral raw material. The roasting of mineral raw materials as preparation for mineral processing can change the target component into a form of easy leaching or physical separation. The roasting operation produces calcine or sinter blocks, and dust, and the target component is recovered from each product with the corresponding method.

The roasting process is completed in the roaster. Under certain temperature and atmosphere conditions, a heterogeneous chemical reaction occurs between the mineral raw material and the gas in the roaster at the solid-gas interface, following the second law of thermodynamics and the law of mass action. The change of free energy in the reaction process can be expressed as follows.

$$ \Delta G=\Delta {G}^{{}^{\circ}}+ RT\ln Q=-...