Grade Control School 2019

Background

Grade control, the activity between Ore Reserve Estimation and product delivery to the metallurgical processes, is integral to efficient mining extraction and essential in achieving the life-of mine plan. It can be the biggest value-add or -loss steps in a mining operation. The wide spectrum of people skills and activities is coordinated and integrated to control the quality of material sent for processing. A thorough understanding of the geological model, the nature of ore distribution, the mining method and metallurgical processes for metal extraction, are critical inputs for efficient grade control. Sampling and supporting grade estimation methods inform the optimal Standard Mining Unit (SMU) size, which in turn is matched to available mining equipment in order to efficient extract the ore with minimal ore loss and dilution. Liberating the ore through blasting and the subsequent movement, stockpiling and blending of material to its handover points using strong control process, is essential to successfully minimising wastage.

Detailed reconciliations of the estimation and mining processes allow for maintenance and improvement of the economics of the operation. The relatively new discipline of Geometallurgy is seen as key to improving the grade control process in future.