Some Mining Applications Of Unsaturated Soil Mechanics

Abstract

Unsaturated soil mechanics continues to play poor relation to saturated soil mechanics, although an unsaturated soil at a given density is stronger, less compressible and less permeable (i.e. performs better) than the same soil in a saturated state. There are many examples of unsaturated conditions in the mining field, including the wetting-up and drain-down of initially dry surface waste rock dumps; the irrigation and drain-down of heap leach materials; the drain-down, desiccation and rewetting of mine tailings; the dewatering of mineral products such as coal; the shear strength and compressibility of stored mine wastes; and the performance of geo-covers placed on mine wastes on rehabilitation. This paper highlights the key unsaturated soil mechanics parameters, overviews the nature of mining and processing wastes, and some products, and discusses the issues involved. Some applications of unsaturated soil mechanics addressing the shear strength, compressibility and permeability of mine wastes, and mineral products, are presented, together with data to highlight them.