Rock quality designation (RQD)--an useful tool for blast design in surface mines

摘要

Selection of mining methods vis-a-vis excavation system holds much importance in view of the nature of the rock type and its variable strength characteristics generally encountered during bench blasting. Blasting plays an immense role since the physico-mechanical properties of rock, govern the process of fragmentation and displacement of rock muck pile. Several studies and field trials have been undertaken by the authors to evolve proper explosive selection, so as to result in optimum fragmentation and better productivity. An attempt has been made in this paper to identify the various physico-mechanical properties of rock in blast design and its correlation with fragmentation results. A number of studies have since been done on laboratory scale and attempt is made to establish the same in the field. Rock quality designation (RQD) was found to be one of the most useful parameter in blast design and evaluation. The encouraging results of the study will definitely benefit the blast design engineer and productive units and will immensely benefit the mining operators.