Blast cone sampling is an important part of the mining process, used for grade control particularly in iron ore mines. It has, until now, involved personnel traversing potentially uneven ground undertaking highly repetitive manual tasks, including digging and lifting samples of drilled material, approximately five kilograms in weight. Blast patterns can also pose other significant risks to personnel who operate in these environments, including heat-related illnesses, repetitive strains, and geological risks such as voids and wall failures.  

To help address these risks, BHP developed, in partnership with technology developer Sorden and the CSIRO, a ‘blast hole assay tool’ (BHAT). The BHAT is a neutron logging tool that emits neutrons into the area surrounding the blast hole wall.  These neutrons are converted to gammas, which are captured by the tool and converted into multi-element geochemical assays, delivering real-time, multi-element geochemical assays. The BHAT utilises data analytics and automation to replace manual tasks associated with collecting blast cone samples, while a semi-automated logging truck ensures the operator does not need to leave the truck and be exposed to the risks identified above. The BHAT and logging trucks undergo regular calibration and maintenance to ensure quality assurance and control, with the data continuously monitored across various time horizons (daily, weekly and monthly).   

The implementation of the BHAT and use of semi-automatic logging trucks has seen a change in the work environment from manual and repetitive digging and shovelling to operators driving and working in air-conditioned and ergonomic vehicles. This had led to a reduction in manual handling injuries associated with manual blast cone sampling.