Matéria (Rio de Janeiro)
On-line version ISSN 1517-7076
BARATA, M.S. and ANGELICA, R.S.. Pozzolanic activity of kaolin wastes from kaolin mining industry from the Amazon region. Matéria (Rio J.) [online]. 2011, vol.16, n.3, pp. 797-810. ISSN 1517-7076. http://dx.doi.org/10.1590/S1517-70762011000300007.
The Capim and Jari regions, northern Brazil, are the main Kaolin mining areas in the Amazon region. They encompass the biggest high-grade (high whiteness) kaolin reserves for the paper coating industry. During the beneficiation of this kaolin, different kinds of processed and non-processed wastes are generated. The main objective of this work was to evaluate the reactivity of pozolans produced after calcinations and milling of such residues, by the comparison of the mineralogical composition and the type of kaolinite from the two regions (different kinds of structural order/disorder). The heating temperature to produce the pozolans was evaluated in order to obtain the better reactivity with lower energy consumption. The results showed that the pozolans obtained from both residues exhibited high reactivity, also better than those commercially available. Those obtained from kaolinites with high structural defects needed lower temperatures in comparison with low-defects kaolinites. The use of the former kaolinites reduces the production costs to obtain pozolans without losing quality in terms of reactivity
Keywords : kaolin wastes; pozzolan; metakaolin; calcination; high reactivity.