Exfoliation and textural modification of anthracites

Two anthracites (La Mure, France and Hongay, Vietnam) have been exfoliated after intercalation in a perchloric and nitric acid solution followed by a thermal shock treatment. The anthracites are extensively exfoliated as shown by scanning electron microscopy, and this treatment is responsible for a significant development of mesoporosity and a great increase of specific surface area. Hongay anthracite was then steam activated, and specific surface areas of 1200 m(2)/g have been obtained with a well developed mesoporous texture. Moreover, after exfoliation, the anthracite reactivity with water vapour during steam activation is increased by a factor of 3. This shows that anthracites may be an important source of raw materials for the production of active carbons with a large pore size distribution. Copyright (C) 1996 Elsevier Science Ltd.