Improvements in or relating to the treatment of materials for employment in chemical reactions as catalysts, catalyst supports, fillers, constructional materials for the reaction vessels or linings thereof, and to the employment of such materials in chemical reactions

摘要

Materials for use as catalysts, catalyst supports, fillers, or constructional materials for reaction vessels or linings thereof are freed from metallic impurities (particularly iron) by extraction with an oxycarboxylic acid. The invention is particularly applicable to graphite, fireclay, bauxite, and pumice. Tartaric, malic, and lactic acids are mentioned as extraction agents. The acid treatment may be followed by treatment with a volatile solvent, or by a non-volatile solvent followed by a volatile solvent, in order to remove the acid and the metallic salts formed by it. Suitable solvents are formic, acetic, and strong hydrochloric acids.