Research Processes of Hardening Roasting of Phosphorite Pellets with the Addition of Coke Fines

Chemical and energy technological processes occurring in phosphorites and phosphorus-containing rocks, their influence on structure and composition at firing are considered. The possibility of application of existing methods of determination of sintering kinetics for modeling the firing of phosphorite pellets is analyzed. The results of studies of chemical and energy technological process of phosphorite pellets firing with coke addition by methods of thermal and structural analysis are given. It is established that the main parameters influencing the interaction of coke with the pellet material are the heating rate up to the firing temperature, the coke concentration in the pellet and the oxidizer concentration in the heating gas-heat carrier. It was found that the sintering process of phosphorite pellets is preceded by significant changes in the chemical composition, structure and properties of the initial components. The intensity of these changes is determined by the temperature, composition and pressure of the gas phase, which can be inhomogeneous at different points of the studied samples.