In South African, coal is generally screened into the nominal commercial sizes such as rounds, cobbles, nuts, peas and duff.
Reference:
Van der Walt, P. 1956. Sizing of coal (Witwatersrand University Coal Preparation course 3rd Year Coal Mining Students). http://hdl.handle.net/10204/12976 .
Van der Walt, P. (1956). Sizing of coal (Witwatersrand University Coal Preparation course 3rd Year Coal Mining Students) Retrieved from http://hdl.handle.net/10204/12976
Van der Walt, PJ Sizing of coal (Witwatersrand University Coal Preparation course 3rd Year Coal Mining Students). 1956. http://hdl.handle.net/10204/12976
Van der Walt P. Sizing of coal (Witwatersrand University Coal Preparation course 3rd Year Coal Mining Students). 1956 [cited yyyy month dd]. Available from: http://hdl.handle.net/10204/12976