Australian open cut coal mine blasting practices and trends

During the last two decades, many advances have been made in open cut coal mining technology as new mines have come on stream and old mines have faced increasingly difficult mining and operational conditions. The need for close control of operating costs has necessitated consideration of modified excavation methods. Mining systems now often include: truck/shovel prestripping ahead of dragline operations; dragline high walls of 50 meters; total pit depths in excess of 80 meters; mining of multiple coal seams, thin seams and thin partings; more focus on (and measurement of) excavation equipment productivity; and/or conformance to strict environmental limitations. To meet these challenging requirements, innovative explosive products, initiating explosives and delivery systems have been developed. Suitable blasting techniques such as throw blasting also assist coal mining operations to maintain competitiveness in a tough economic environment. This paper examines some of the changes in blasting practices in both open pit and strip mines throughout the Australian coal industry and considers some of the trends for the future.