New materials from industrial and mining wastes: glass-ceramics and glass- and rock-wool fibre

The need to find economically and environmentally more viable methods for the management of industrial wastes has opened the way to the research and development of processes which were still in the laboratory only a few years ago. The examples given concern two very common and acutely-felt problems: the inertization and recycling of hydrometallurgical red muds (RM) and of mine tailings. In the case of red mud, one potential process involves the extraction of metals (mainly Zn, but also Cd, Sn, Pb, Fe), and another involves mixing the RM with granite chippings and cullet to produce glass-ceramics materials via melting and crystallization. The paper also discusses a new flowsheet in which mine tailings are utilized to produce either glass-wool or very strong glass-ceramic products, with good resistance to chemical attack. (C) 1998 Elsevier Science B.V.