AME Roundup 2019 in Vancouver, BC, finished on 31 January 2019, and here are my observations about some of the events. (Previous post: The BC Copper Advantage, Jan. 29, 2019)
2. Mining Methods and Sorting Systems to upgrade BC Porphyry Mines – UBC
The strongest statement Dr. Bern Klein of the Norman B. Keevil Institute of Mining at UBC made during his presentation at AME Roundup 2019 was this:
“Technology can convert low grade deposits into high grade deposits.”
Had a mine project owner said what Dr. Klein did, about their resource, there might have been raised eyebrows from skeptics. However, Dr. Klein had a legal leg to stand on, and presented proof to back up his statement. He was referring to the approach and benefits of using sorting technologies very early on in the mine design process – as early as drilling and sampling and the feasibility stage – to determine the heterogeneity of the rock, the general principle being that high heterogeneity means better sortability, and low heterogeneity means lower sortability.
Dr. Klein mentioned a few of the ore sorting technologies currently in use; Radiometric, GEOSCAN-C PGNAA (Prompt Gamma Neutron Activation Analysis) from Scantech, Australia, HSXRF BeltSense™ from MineSense and ShovelSense™, also from MineSense™.
He described how bulk sampling technologies on copper mines, particularly those using Block and Panel Caving methods, have been implemented to get improvements in ore grade and reductions in waste rock generation and power use. The main idea there is to determine whether the rock goes to the processor or to the waste dump. Dr. Klein illustrated the noticeably accurate tracking of ore makeup as identified by a sorting system as compared with assay results.
Quoting Elberel Erdenebat’s 2012 study, he explained that at New Gold’s New Afton Mine, Scantech’s MineSense is being used with XRF scans on shovels. The ShovelSense system with XRF is very accurate in predicting grade. He said that “finer ore SMU [selective mining unit] sizes positively impact the NPV over the Life of Mine. Shovel SMU gives 79% improvement on NPV over the base case, shovel plus muck – 47%.” Those are impressive percentages. Dr. Klein and his associates have researched this subject extensively.
In a white paper, he says about the sensor-based ore sorting study incorporating bulk and particle sorting systems at New Afton, that;
“…It was found that the concept demonstrated an improvement in the net smelter return of excavated material.”
Well, any technology that results in measurable production improvement is good news.
Next: New Afton: An overview of a successful BC block cave – New Gold Inc.
Banner: New Afton Gold Mine, aerial view, photo from website of New Gold.