SORPTION AND ION-EXCHANGE PROCESSES Influence of Combined Treatment before Activation on the Development of Pore Structure of Anthracite

The influence of surface oxidation of anthracite with humid air, followed by impregnation with alkali metal compounds and calcination in inert atmosphere before activation, on the efficiency of steam gas activation and on the development of the pore structure of the resulting carbon adsorbents was studied. Coals are a major raw material for preparing vari- ous carbon adsorbents (1, 2). Among them, the most attractive is anthracite because of increased content of carbon and low ash residue; furthermore, activated carbon prepared from it has high mechanical strength. At the same time, the activation of anthracite for preparing sorbents is impeded by its low reactivity in high-temperature contact with traditional gaseous ac- tivators, superheated steam and carbon dioxide. This is due to the high degree of metamorphism of anthra- cite (well-organized supramolecular structure with short-range and partly long-range order). Therefore, direct gas steam activation of anthracite often fails to develop its pore structure and attain the high specific parameters of porosity.