Of all the wastes produced by industrialized man, the largest tonnage and volume, by far, consists of mining wastes. The environmentally acceptable disposal of mining wastes has many facets or issues and these vary with the mineral being mined and with the topography, geology and climate of the mine site. This paper, written by authors from southern and northern hemisphere countries, addresses four of the most important issues concerning the management of mine wastes and tailings.
Of the wastes produced by man in the course of his industrial activities, mining wastes far outstrip all others in terms of tonnages produced and land surface sterilized as a result of their disposal or storage. For example, in the South African deep level underground gold mining industry during the past century, over 8000 million tons of ore have been mined, hoisted to the surface, milled, extracted and disposed of. These figures are small in comparison with corresponding figures for open pit mining waste and overburden tonnages. These vary with the type of mine, the mineral being mined (and hence the characteristics of the waste), and are also deeply affected by the topography, meteorology, surface geology and climate of the mine site.
Several tailings dams have failed as a consequence of earthquakes in different parts of the world. A summary of case histories of failures in Chile is presented in Table 1.1. Analyses of these failures indicate some common features. It is worth to consider these in detail in order to use this valuable experience for design, both to prevent the occurrence of similar problems in new projects and to strengthen existing dams.