The paper describes the BOS method and a test performed at a large copper mine.

The test was conducted by utilizing an on-line XRF-analyzer and a belt scale on the mine main conveyor belt for measuring continuously the copper contents of the primary crushed ore in 30 second batches for Bulk Ore Sorting.

Ore and waste rock dilution tonnages and grades were measured. During the five week’s test 4,5 million tons of presumed ore was analyzed and 286 000 tons of below cut-off waste rock was detected for BOS.  While the average grade of the ore was continuously above the cut of grade the used 30 second analysis time (the below blue line) reveled that significant amount of ore was below the cut grade.

To read more about the study please download the complete white paper below. This paper was fist presented at Procemin-Geomet 2021.