Mine Tailings from the Lateritic Gold Mine Igarape, Bahia (Carajas Region), a Basis for Active Hydraulic Binders

摘要

The article summarizes the results of different works on the mineralogy and technical application of lateritic gold mine tailings at lgarape, Bahia. As a consequence of the mining activity at lgarape, Bahia about 2 million tons of mine tailings are produced annually. This material can be recycles and used as a basis for active hydraulic binders. These binders are synthesized at temperatures below 1250 °C and contain a high amount of iron. They could replace, at least partially, expensive portland cements and be used for construction purposes. To investigate the possibilities to produce hydraulic binders using mine tailings, waste material was mixed with lime, China clay and anhydrite, and sintered t different temperatures on a laboratory scale. The products were analyzed for their phase composition and their hydraulic reactivity. With mixtures of lime, 2CaO~*SiO_2, a common hydraulic phase can be formed. With the addition of a sulfate component a 2CaO~*SiO_2 - 3CaO~*3Al_2O_3~*CaSO_4 cement can be synthesized.