Performance of dry separation processes in cenospheres recovery from coal fly ash

Many researchers have recently been very interested in the recovery of valuable materials from fly ash. One of them is cenospheres, which are beneficial for light weighted material components due to their physical and chemical characteristics. Cenospheres recovery technologies are mostly based on wet separation process due to their density, which is lower than water density. Meanwhile the possibility of dry separation process has not yet been fully explored. In contrast to wet separation, a dry separation process provides substantial benefits. These benefits include: much less land consumption and reduced levels of pollution related to the leaching of toxic materials from coal fly ash. In this study, experimental work has been conducted using two types of dry separation processes: a pneumatic separator closed type and a micron separator. Comparing the two alternative techniques, the micron separator obtained Newton's efficiency higher than that of pneumatic separator closed type and showed a better degree of separation. Cenospheres recovery, particle distribution and visualisation of both underflow and overflow product using Scanning Electron Microscopy (SEM) were also performed to comprehensively depict the separation performance of both dry separation processes. It was found that micron separator's Newton's efficiency tendency is in line with the estimate, showing that dry separation process achieves a degree of separation as high as the commonly used technology which is wet separation process.