Dry bulk density (DBD) of rocks

Abstract

The dry bulk density (DBD) is determined as dry mass of a rock (i.e. excluding natural moisture) per unit of actual in situ rock volume, including porosity. Despite of an obvious importance of the density for accurate estimation of resources and reserves it is often overlooked and receives significantly less attention then assayed metal grades. In this chapter the commonly used DBD measurement methods applied for the different material types, including competent non-porous rocks, weathered and porous rocks, soft partially cemented sediments and unconsolidated free flowing sands, are briefly described and their strengths, weakness and the main error sources are explained. It is shown that the bigger challenge is construction of an accurate 3D model of the rock densities distribution at the studied deposit.