Process Development for Solid Fuel Use at Siderite Ore Roasting in Shaft Furnace

Lean coal burning kinetics was studied and the main burning rate dependence on oxygen content in gas phase and heating rate was obtained. Preliminary dressed lump siderite ore from Bakal deposit with the fraction of 18-25 mm and average iron content of 35% was roasted in a pilot unit in neutral (low reducing) atmosphere, obtained by coal grate firing. It was established that such roasting allowed iron oxidation level reduction, as compared to roasting in oxidizing atmosphere and iron content increase in the roasted product. The evaluation results allowed development of a roasting process for siderite ore in neutral (low reducing) atmosphere and designing of a shaft furnace operating on solid fuel. Such roasting process is of a certain interest, as far as saving the insufficient fuel types, and predominantly natural gas, is concerned.