Modelling of the thermal treatment effect on the pellets mass in the technological zones of a roasting machine

The article is devoted to the investigation of chemical processes occurring during the thermal treatment of iron ore pellets on a conveyor roasting machine. Obtaining the desired quality of raw materials requires a comprehensive research and determination of the physicochemical composition of the charge materials. The purpose of the study is to determine the mass of pellets in each zone of the roasting machine. Before the beginning of the work of the roasting machine, the input of raw pellets mass is carried out, their moisture, chemical composition is defined. The giv-en parameters make it possible to calculate the temperature regime in each technological zone of the roasting machine. Simulation is carried out with the help of the software product LabVIEW, which allows to simulate the thermal process of making pellets. The article considers the influence of chemical reactions on the physical and mechanical properties of the material for each technological zone of the conveyor roasting machine. One of the main indicators of the pellets quality is the moisture removal from the pellets, which occurs in the drying zone. The specified moisture content in raw pellets makes it possible to calculate, if necessary, the amount of fuel that will be used to remove water, and also reduce the risk of non-optimal temperature regime, which may reduce the strength of the pellets. The oxidation process of magnetite into hematite begins at a temperature of 1000C, which results in the mass of raw pellets increase. The mass of pellets is viewed in each technological zone of the roasting machine, which makes it possible to monitor the processing of iron ore material. It is proposed to control the burners of the conveyor roasting machine by means of changes of the mass that influence on the temperature changes. It will increase the productivity of the roasting machine and reduce fuel consumption. The results are presented in the graph. It was determined that the fired pellets mass has been reduced by 6-10% as compared to the original mass of the raw pellets