2022 Volume 76 Issue 1 Pages 521-527
Coal gasification slag, by-product of combined cycle coal gasification combined cycle power generation, is expected to be used as a fine aggregate for concrete. Although a number of experimental studies have been conducted as a fine aggregate for concrete, there have been few experimental studies on the chemical properties of slag. We attempted to elucidate the silicate structure of coal gasification slag by combining the examination of insoluble residues by dilute hydrochloric acid solution, measurement of siloxane chain length distribution by trimethylsililation method, and solid-state NMR. Contrary to the expectation that the silicate structure of slag is mostly composed of amorphous phase, mainly glass phase similar to fly ash, some slag with high CaO/SiO2 molar ratio was found to be composed of siloxane oligomer with relatively short chain length similar to blast furnace slag.
