Use of High Pressure Water Jets as a High Efficiency Tool for Coal Comminution

The advantages of using high pressure water jets as a new technique for breaking coal into particles of an ultra fine size distribution are reviewed in this paper. The results of a preliminary investigation of the technique are presented. These data indicate that the lower levels of energy required of this comminution process, in contrast to that required by conventional technology, improve the practical viability of using fine powdered coal in industrial processes, when the waterjet comminution is included in the grinding cycle. The compressive stress mode of failure induced in conventional milling processes is changed in waterjet comminution to a tensile failure by extension of existing particle boundaries, and the benefits of this change in failure mode are reviewed