METHOD OF TREATMENT OF FILTERING MATERIAL USED IN FILTER WITH LOOSE LAYER Russian patent published in 2002 - IPC

FIELD: filter used in water treatment processes. SUBSTANCE: method of treatment of anthracite includes crushing, separation of working fractions of crushed anthracite by screening, wetting of working fractions in diluted acid solution followed by their flushing to neutral reaction. Before crushing, anthracite is subjected to two-stage heating under vacuum. At first stage, heating is effected at temperature of 150 to 300 C till completion of distillation of constitutional moisture. At second stage, heating is effected at temperature of 500 to 700 C till completion of sublimation of volatile substances and sulfur when distillation of constitutional moisture is completed and decomposition of inclusions of pyrite accompanied by liberation of sulfur dioxide and carbonate inclusions accompanied by liberation of carbon dioxide take place. EFFECT: increased porosity of filtering material; improved quality of water purification. 1 tbl