浮遊選鉱法による石炭の脱灰特性に関する速度論的検討

Abstract

The objective of this research is to develop a new froth flotation method to be employed in CWM (Coal Water Mixture) preparation. The froth flotation method is famous for practical coal cleaning, but it has some problems relating to CWM preparation. In conventional flotation method, deashed coals tend to coagulate because much oil used as a collector is included in them. Therefore, it seems to be difficult to disperse the deashed coals into water in preparing CWM. Accordingly, its important to increase the carbon recovery rate by making use of the small amount of oil.In this report, the kinetic study of carbon recovery was made using coals with wide size distribution which is suitable for CWM preparation. The flotation method used here is different from the conventional one at the point that collector is fed in the form of gas.Carbon recovery rates for various coals were found to obey the first order kinetics with respect to carbon concentration in the suspension. The rate constants were found to correlate well with the O/C atomic ratio of the coals. Coal concentration of the feed suspension had no effect on the recovery rate when it was smaller than 10%. But at higher concentration, a large decrease of carbon recovery was observed.