Coal ash tends to become containing more unburned carbon and porous substances depending on conditions of combustion, whose adverse effects to products due to water adsorbability, absorbability and color tones create obstacles in its utilization. Therefore, research and development works have been progressed on wet type carbon removing technology which is characterized in that coal is pulverized to preferable degrees and subjected to flotation. This paper reports the results obtained during fiscal 1995. The results may be summarized as follows: as a result of the comparison test on a column flotation machine and an FW type flotation machine of machine stirring type, the former machine showed better flotation efficiency; several methods were investigated on crushing as a treatment prior to flotation, whereas a mixer with greater circumferential speed and a homo mixer showed the highest efficiency; strength of the impact to the flotation efficiency was found to decrease in the order of pulp concentration > pretreatment time > collector addition ratio; and as a result of the evaluation on refined ash as a cement admixture and carbons as fuel, possibilities were found in them for practical application. 16 figs., 2 tabs.