Basalt rock as an alternative raw material in Portland cement manufacture

摘要

The possibility of using basalt rock, which has relatively limited uses, instead of clay in cement industry is investigated. Two clinker mixtures were prepared according to the composition : (87 wt./100 limestone + 12 wt./100 clay or basalt rock). To compensate the lack of iron in clay clinker mixture and the lack of silicate in basalt clinker mixture, 1 wt./100 Fe_2O_3 was added to the clay clinker mix and 1 wt./100 sand, as a source of silicon oxide, was added to the basalt clinker mix. Each clinker mixture was ground, then fired at 1500℃ for 2 h then quenched in air. Each produced clinker was ground to a Blain area equal to 3000 cm~2/g and mixed with 5 wt./100 natural gypsum and 24 wt./100 water. The produced pastes were molded in the 1-in.~3 molds. The compressive strength test was performed at 7 and 28 days of hydration. Chemical composition analysis, X-ray fluorescence analysis, X-ray diffraction analysis and Mossbauer effect measurements were performed on the raw materials and on the produced clinkers. It was found that basalt is a typical raw material, with little addition of sand, to replace clay in producing Portland cement clinker as a source of aluminum silicate. This means that new cement factories could be established at different localities at which clay is not found, while basalt rock is available.