The article presents results of theoretical and experimental studies of the processes of iron solid-phase reduction from an iron-containing concentrate obtained as a result of hydrometallurgical dressing of ferromanganese and polymetallic manganese-containing ores with coals of grades D (long-flame) and 2B (brown). The method of thermodynamic modeling using TERRA software complex was used to study the reducing properties of hydrocarbons by calculating equilibrium compositions in the temperature range of 373 - 1873 K. The authors obtained the dependences of compositions and volume of the gas phase formed as a result of the release of volatile components during heating on the temperature for the coals of the grades under consideration. As a result of thermodynamic modeling, the optimal temperatures and consumption are determined, which ensure the complete iron reduction from an iron-containing concentrate. The results of experimental studies were obtained by modern research methods using laboratory and analytical equipment, as well as methods of statistical processing. Results of the coals analysis carried out using the Setaram LabSys Evo thermal analyzer showed that the process of thermal decomposition of coals of the studied grades proceeds according to general laws. The process of thermal decomposition of long-flame coal proceeds less intensively than of brown coal. The results of an experimental study of the processes of thermal decomposition of reducing agents have shown that volumes of the gas phases, formed when coals are heated to a temperature of 1173 K in an argon atmosphere, practically coincide with the calculated values. As a result of thermodynamic modeling and experimental study, the optimal consumption of D and 2B grades of coal is determined at a temperature of 1473 K. The best reducing agent with a minimum specific consumption is long-flame coal of D grade. When determining the optimal amount of reducing agent in charge mixtures during the study of metallization processes, it was found that with an excess of reducing agent, it is possible to achieve almost complete extraction (98 - 99 %) of iron from the concentrate.
THERMODYNAMIC MODELING AND EXPERIMENTAL STUDY OF RICE HUSK PYROLYSIS
