The Use of RTK GPS in Blast Optimization

Planimetric control positioning and detail pickups using the Real Time Kinematics (RTK) Global positioning System (GPS) is emerging as one of the fastest, reliable and more accurate method of surveying in surface mining. This paper seeks to highlight how the RTK GPS from Trimble is being employed at Gold Fields Ghana Limited, Tarkwa Mine to provide accurate drill depth and drill pattern design. The usage, problems, processing and efficiency of this system in a mining environment is also explored. It also looks at the level of accuracies provided by this system. Before the introduction of RTK GPS into the blasting process, the current blast fragmentation was resulting in sub-optimal feed size to crushers on the Mine and an unfriendly floor conditions resulting in excessive sheeting of digging floor to prevent tyre damage. It was decided to use RTK GPS to improve the fragmentation through accurate drill depth and design pattern in order to achieve a constant throughput to the north heap leach crusher of 1500 t/hr, a 5 % increase in pit loading efficiency and a 50 % decrease in rock breaker hours, equipment damage costs and in-pit sheeting costs respectively. This paper is intended to take the reader through the application of RTK GPS in accurate drill depth and drill pattern which have resulted in a 10 % reduction in loading times, of which half has been attributed to improved fragmentation, as well as a substantial increase in blasted stocks whiles rock breaker hours have also decreased resulting in substantial financial gains to the company. TS 1C – CORS-RTK