In-truck ore grade estimation using apparent density measurements

Abstract

The Rio Tinto Iron and Titanium (RTIT) Havre St-Pierre (HSP) mine located in Quebec, Canada has implemented a grade estimation system based on the determination of the apparent density of the material loaded into mine trucks. The system is used to segregate economic ore from waste as part of the re-handling of a historical waste stockpile. The system takes advantage of the strong relationship established between ore density and grade for the HSP mineralization. The apparent density is derived from the measurements of (i) the volume of the truck load using a laser-based scanner and (ii) the mass of the truck load provided by an onboard truck scale. The ore grade is then calculated by applying a void factor to the apparent density measurement. In the future, this in-truck grade estimation technology could be expanded to the entire mine operations and be instrumental in ore vs waste discrimination and production reconciliation.