Departmental Seminar

The coupling between rock texture and breakage: A case study on a porphyry copper ore sample using X-ray microCT

Dr Yulai Zhang
Postdoctoral Fellow, Department of Materials Physics, ANU

As the mining industry continues to seek greater energy efficiency, it needs more effective characterization of ore material as it progresses from mine to mill. The energy cost of ore mineral liberation, for example, is critically dependent on management of rock breakage from blasting to comminution. The study reported here presents a quantitative 3D characterisation of ore texture and breakage based on X-ray micro-CT and in-situ micromechanical testing. A porphyry copper ore is studied from its initial mechanical failure to the onset of fragmentation. This work integrates a quantitative ore textural analysis with 3D mapping of both the dominant minerals and microporosity in the ore sample. It enables us to show, as the fractured ore is still under loading, that internal breakage of feldspar grains (plagioclase and alkali feldspar) dominates grain boundary fracturing. We discuss how the microporous regions, mostly found in hydrothermally altered plagioclase, may act as a weakening factor leading to the dominant breakage of plagioclase. We measure quantitatively and discuss how size reduction, ore texture and breakage characteristics control the degree of liberation of Cu minerals. Combining 3D characterisation of ore texture and breakage characteristics could provide much needed insights for achieving more energy-efficient comminution and optimal liberation of critical minerals.

Date & time

Thu 24 Nov 2022, 11am–12pm

Location

Room:

Huxley Teaching Room (H4.20)

Audience

Members of RSPE welcome

Contact

(02)61250185