This work was conducted to find the operating characteristics of a wet grinding system designed to obtain fine rice husk ash powder To find better utilization of the rice husk, a valuable by-product from rice production, once the rice husk was combust...
This work was conducted to find the operating characteristics of a wet grinding system designed to obtain fine rice husk ash powder To find better utilization of the rice husk, a valuable by-product from rice production, once the rice husk was combusted and the thermal energy was recovered from the furnace, tile ash was fed and pulverized in the grinding system resulting a fine powder to be used as a supplementary adding material to the portland cement, In order to develop an efficient grinding system to produce the fine powder of rice husk ash for use of a supplementary adding material to the portland cement, we tried to analyze how the operating factors affected the grinding characteristics of a grinding system.
Grinding time(15, 30, 45 min), impeller speed(250, 500, 750 rpm), and mixed ratio(6.7, 8.4, 11.1, 20.9) were three operating factors examined for the performance of a wet-type stirred ball mill. For the operating condition employed in wet find grinding, mean diameter of fine ash powder, specific energy input, and grinding energy efficiency were in the range of 2.83~9.58 μm, 0.5~6.73 kWh/kg, and 0.51~3.7 m2/Wh, respectively. With the wet-type stirred ball mill used in this study, the grinding energy efficiency decreased with the increase in total grinding time, impeller speed, and mixed ratio. The difference in specific surface area of powder linearly increased with logarithm in total number of impeller revolution and the grinding energy efficiency linearly decreased. Grinding time of 45 min, impeller speed of 500 rpm, and mixed ratio 6.7 were chosen as the best operating conditions of the wet fine grinding. At these conditions, mean particle diameter of the fine ash, grinding energy efficiency, grinding throughput, and specific energy input were 2.837 μm, 2.28 m2/Wh, 0.17 kg/h, and 2.03 kWh/kg, respectively. Wet fine grinding which has no fly dust causing pollution and makes continuous operation easy, is appeared to be used for automatization of grinding processing.