Processing of Fines with Low Ash Content.

In 1972 the processing section of Freyming of Houillieres du Bassin de Lorraine with a capacity of 1500 ton/hr of run-of-mine coal (150-0 mm) was equipped with a special facility which makes it possible to produce 8-2 mm fines of no more than 1. 7% by weight of ash from the washed fines (8-0 mm) discharged from the conventional dressing plant. This product is called ″low-ash fines.″ These fines must be characterized by a ratio between iron and solid carbon (Fe: C) of less than 0. 33%. The special processing facility consists essentially of heavy medium separating cylinders. The specific gravity of separation is kept constant by a pneumatic control system.