Experiment on Decarburization of High Carbon Fly Ash and Preparation of Concrete

The raw fly-ash applied in this study has an ignition loss of 17.30 %. The results of floatation experiment show 4.40 % coal content of tailing ash. The screen analysis results on decarburized fly ash shows that the content of +45 μm is above 12 %, failing to meet the quality of Grade I fly ash determined in the standard of China. Therefore, the decarburized fly ash was processed by grinding to meet the required quality. The analysis of the main constituents of different grinding methods conducted for tail fly ash shows that fly ash obtained by open circuit ball mill are the most suitable one used as admixture of concrete. Comparisons were made on the compressive strength and bending strength of 7d and 28d under the conditions of non-grinding and five ways of grinding. The test results show that grinding can improve the compressive strength of fly ash concrete. By way of closed-circuit grinding rod mill, concrete, can fly ash concrete strength be increased remarkablely.