Experimental Study of Packed Bed Heat Transfer in a Shaft Kiln to Pre-Heat Manganese Ore with Hot Air

Research work to demonstrate the feasibility of using hot air to preheat manganese ore to 600˚C before feeding into a submerged arc furnace is underway. A shaft kiln will be used as the transfer unit where energy transfer takes place by passing hot air through a packed bed of manganese ore. This paper report on the results obtained from experimental measurements of the transfer process at the air-manganese ore interface. Hot air at 650˚C was produced with an electrical heater and fed into a packed shaft type column. As a requirement for continuous unit operation, the transient analysis provides details of the required residence time before materials flow to the furnace can meet temperature requirements. Understanding of the transfer processes provides optimum column sizing and process control information to be used as the basis for scaling the shaft kiln design for preheating of manganese ores. This will enable the use of concentrated solar thermal power to preheat manganese resources with air used as the thermal transfer fluid.