3D visualisation of portable X-ray fluorescence data to improve geological understanding and predict metallurgical performance at Plutonic Gold Mine, Western Australia

Abstract

The amphibolite-facies metabasaltic rocks of the Mine Mafic Package at Plutonic Gold Mine, Western Australia, contain an estimated endowment of 10?5 Moz of Au. A preliminary study based on portable X-ray fluorescence (pXRF) analyses identified a geochemical stratigraphy which strongly controlled the location of Au mineralisation. The present study incorporates a significantly larger pXRF dataset and presents the data in a three-dimensional framework. This dataset allows an investigation of the mineralogy of Au mineralisation with varying geochemical associations across the deposit. Historically, high As content in the mill feed resulted in poor metallurgical performance. Seamless data integration of the pXRF dataset allows for recognition of the different styles of Au mineralisation based on Au/As ratios, and visualisation of the distribution of these different mineralogical associations in three dimensions. This work enables us to better predict the As concentration of underground ore blocks, and to be proactive in optimising the mill configuration to improve metallurgical performance.

Gold Exploration in Two and Three Dimensions: Improved and Correlative Insights from Microscopy and X-Ray Computed Tomography

“…The XCT data and microscopy data were aligned manually by visually aligning prominent features using commercially available Volume Graphics software [28]. Correlative microscopies in other geoscience studies (e.g., fluorescence microscopy + SEM [34]) have proven to be more precise and can expose the physical and chemical character of ore minerals at a better spatial resolution and analytical precision [35].…”

Petrogeochemical assessment of rock units and identification of alteration/mineralization indicators using portable X-ray fluorescence measurements: Applications to the Fire Tower Zone (W-Mo-Bi) and the North Zone (Sn-Zn-In), Mount Pleasant deposit, New Brunswick, Canada

“…Systematic pXRF analysis of drill cores of the Mount Pleasant deposit can produce a 3D model to show different rock units or mineralization based on either element concentrations (e.g. Gazley et al, 2011a) or PCA scores (e.g. Chen et al, 2015).…”

“…Chen et al, 2015). These models built on the large pXRF datasets can guild the exploration activities in this area and attribute metallurgical performance to predict metallurgical recovery in different ore blocks (Gazley et al, 2011a). 2) In comparison with the immobile elements Nb and Y, some rock units (mostly the breccia) have significant Rb and K depletion that was caused by greisen-type alteration close to the orebodies and distal propylitic alteration.…”

“…Vaillant et al (2014) used the pXRF to acquire Cr, Ni, and Ti data to effectively explore for komatiite-hosted nickel sulphide deposits. Gazley et al (2011a) investigated the Au/As ratios of rocks by pXRF to define different geochemical domains of Au mineralization. Coupled with preliminary metallurgical testing the pXRF dataset would attribute metallurgical performance to predict metallurgical recovery in different ore blocks.…”

An innovative optical and chemical drill core scanner

“…Portable/handheld XRF instruments are gaining popularity and have been applied widely and successfully to analyse drill cores in a non-destructive way (e.g. Gazley et al, 2011Gazley et al, , 2012Fisher et al, 2014;Le Vaillant et al, 2014;Ross et al, 2014). Advantages of the new instrument over handheld XRF instruments are a better and more representative coverage (continuous scanning vs. point analyses), reduced labour, standardised analytical conditions, integrated routines, and advanced data handling.…”