EFFECTOFTHE TYPE OFCARBON MATERIALON THE REDUCTION KINETICS OFBARIUM SULFATE

The present study deals with the reduction of barium sulfate (barite) to barium sulfide by use of carbon as the reduction agent. pellets of barite ore containing about 95% baso4 has been reduced under different conditions of temperature, time, ore grain size and the type and grain size of the carbon materials. graphite, coke and charcoal have been used as the reducing agent and the reduction experiments have been performed in the temperature range of 925- 1150 °c. apart from conducting the experiments using pellets made of ore powder, kinetic analysis of the experimental data by use of the reduced (dimensionless) time method has been another unique feature of the present study. experimental results show that grain size of either carbon material or barite ore has not appreciable effect on the reaction rate. kinetic analysis of the experimental data revealed the rate is strongly controlled by the chemical reaction of carbon gasification (boudouard reaction). the reaction rate is very considerably related to the type of carbon material so that the activation energy varies from 15.6 kcal.mol-1 for charcoal to 26.3 kcal.mol-1 for graphite and 20.8 kcal.mol-1 for coke. this behavior provides further support for the postulated reaction mechanism, i.e., carbon gasification.