EPM 18616 Black Mountain Project Year 6 Annual Report period ending 18 June 2019

URL: https://geoscience.data.qld.gov.au/dataset/cr120512

Golden Gate prospect graphite mineralization samples from diamond drill hole GGDDH 1701 and drill hole GGDDH 1702 were selected for petrological and mineralogical examination, to determine what elements are associated with the graphite and the graphite grain size characteristics, and in particular whether it is present in amorphous or flake form. The graphite was identified as being present in flake form with strong evidence for it being of hydrothermal origin.
Metallurgical test work on the graphite was undertaken by Brisbane Met Labs to determine if high recovery of at least 95% graphite into a flotation concentrate could be achieved, which could then be economically upgraded to a viable graphite product of greater than 95% graphitic carbon. Flotation test work established that a composite sample ground to a grain size of 80% passing 58 microns achieved a concentrate recovery of 94% of the total carbon, but the total carbon grade of the concentrate was disappointing at only 22%. However, when the concentrate was subjected to a two stage caustic bake, an encouraging total carbon grade of 98.9% was obtained.