Influence of pretreatment and activation conditions in the preparation of activated carbons from anthracite

The influence of pretreatment and activation conditions on anthracite activation was investigated. Separation of low ash coals by using dense media was conducted to obtain appropriate raw materials for activation. Activated carbons were produced from crushed and granule coals by physical activation (steam or CO2) and physical activation with chemical pretreatment in mild and strong conditions. Microporous activated carbons having a surface area of 900 m(2)/g were produced by steam activation from granules with 60% burn-off for 3 hrs of activation. Chemical pretreatment at the strong condition increased the surface area by 30% as compared with non-treated activated carbons. Chemical pretreatment, in general, affected activation degree, so pore volume increased by 20% and burn-off increased remarkably at the identical activation conditions. CO2 activation was proven to be an effective method for producing microporous activated carbons having an average pore diameter of 20 Angstrom.