TAILING PONDS – SOURCE OF SILICA RAW MATERIALS POTENTIALLY USEFUL IN CEMENT MANUFACTURE

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-06-5 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 41, 231-238 pp, DOI: 10.5593/sgem2017/41/S18.030

ABSTRACT

Tailings ponds are permeable hydrotechnical structures for retention purposes, specifically designed for safely dumping mining waste from mining operations and for evacuating fluid tailings from mining sites. Tailings ponds are grouped in classes according to their type, intended service life and function at the mining site. Another important criterion of classification is the terrain where the tailings pond is situated. Tailings or mining waste can be defined as the commercially worthless fraction or the waste material which is left over after the extraction and processing of minerals needed in obtaining ennobled materials for various industrial applications. The composition of mining waste varies site-wise depending on the deposit genesis, the mineralogical and lithological composition as well as the preparation and processing techniques. According to D. J. Harrison’s classification of mining waste, the silica mining waste investigated here for its potential use in cement manufacture belongs to the processed silica mining waste category. The tailings ponds considered here for investigation are associated to sand mining pits and pertain geologically to the central part of the External Flysch of the Eastern Romanian Carpathians (between the Vitioarei Fault and the Teleajenului Valley) where the Oligocene retains its characteristic facies—with underlying bituminous horizons and Kliwa sandstone atop. This latter sandstone, consisting of the quartz sands accumulated by the Carpathian Alpine geosyncline, makes up a deposit which has long been in operation. The exploited and ennobled sands have many industrial applications (in the glass industry, fine ceramics industry, building materials industry, etc.). The silica mining waste has accumulated as a by-product of quartz sand preparation from the sand mining pits in operation in the Romanian Outer Flysch and has been dumped in tailings ponds. The physical and chemical properties of the processed silica mining waste and the information concerning its homogeneity within the tailings pond under consideration have led to the conclusion that the processed silica mining waste is suitable for use in cement manufacture. Worthy of note is also the double-win effect of investigating the silica mining waste from tailings ponds on not only rendering mining waste management as a means of turning mining waste into useful raw materials but also on reclaiming the tailings pond sites and re-integrating them into the natural and economic circuit by the mere “disappearance” of the tailing ponds as a result of reclaiming the material accumulated in them.

Keywords: tailings pond, silica mining waste, processed silica mining waste.