Study of Decarbonization Processes During Siderite Ore Roasting

The dissociation process of powdered and lumpy siderite ore in the helium, carbon dioxide and air atmospheres is studied with the use of OD-102 derivatograph. The dependences of dissociation degrees and rates from the temperature are received through thermograms processing. The kinetic equations of powders dissociation from the siderite ore are obtained with the help of complex method. It is determined that found regularities also remain unchanged for the lumpy materials. However, the temperature intervals of decomposition will be different. The received results may be used for optimization of thermal conditions of siderite ore burning in the shaft furnaces which heating causes the decomposition of carbonates within iron-bearing minerals, as well as further endothermic effects. They are necessary to compare the material and heat balances of roasting process, which provide an opportunity to properly determine the fuel-consumption rate and work out recommendationsfor its lowering. Moreover, they are necessary to optimize the design and operating parameters of thermal treatment of siderite ore in the shaft furnaces, which ensure the obtaining of roasted siderite ore in accordance with the requirements applicable to the quality of raw materials during the blast-furnace production. Furthermore, they may be used when working out the methods of reducing roasting and further receiving of metalized iron product rich in iron. Keywords: derivatograph, dissociation process, siderite ore, shaft furnace, roasting, kinetic equations, carbonates, temperature, dissociation degree and rate, heating rate, gas phase, helium, air, carbon dioxid