Research on Thermal Behaviors of Shaft Furnace for Vanadium Extraction from Stone Coal

The shaft furnace for vanadium extraction from stone coal is the roasting equipment with independent intellectual property rights,which has the advantages of smaller initial investment,higher vanadium conversion rate and lower energy consumption,etc.The research on thermal behaviors of the shaft furnace was carried out by means of thermal testing to find out the furnace conditions and energy consumption,and the measures for the energy saving,stable and efficient operation of the shaft furnace were proposed.The conclusions are as follows:① The oxygen concentration and roasting time can basically meet the requirements for pellet roasting with uneven distribution of gas flow in the shaft furnace.②The main measures for stabilizing the furnace performances are ensuring the uniformity of qualities and quantities of the fuel,combustion-supporting and cooling air provided to the furnace and the flue gas from the furnace top,improving the pelletizing process of raw stone coal and keeping the continual feeding and discharging of pellets.③ The thermal efficiency and exergy efficiency of shaft furnace are respectively 71.24% and 37.22%,and the unit energy consumption of shaft furnace is 9.16% higher than that of the rotary kiln and 40.50% lower than that of the flat kiln.④The effective measures for energy saving are recycling the waste heat of the flue gas from the furnace top,enhancing the heat transfer between the pellets and cooling air and increasing the thickness of furnace wall.