GRANULAR ACTIVATED CARBON MANUFACTURE FROM BROWN COAL TREATED WITH CONCENTRATED INORGANIC ACID WITHOUT PITCH

摘要

Granular activated carbon is manufactured from briquettes formed from brown coal from which iron material has been extracted by crushing and screening the pretreated coal briquettes to produce granules, which are treated by mixing with about 5% by weight of concentrated inorganic acid (H2SO4, H3PO4, or HCl) without the addition of a carbonaceous binder such as coal tar pitch. The so treated granules are ground to form fine powder, which powder is compressed into shapes such as pellets and then granulated. These granules are devolatilized, without charring by directly heating to and at a temperature higher than the charring temperature in an oxygen-free atmosphere, and then activated by heating to and at a temperature higher than the devolatilizing temperature in an atmosphere containing a gaseous activating agent. The activated granules have a surface area of not less than about 900 m2/gram, an abrasion number of not less than about 70 and an apparent density of not less than about 0.48 gram/cc, which properties make them suitable for use in water and waste water treatment and in other applications.