Transforming the Mining Value Chain
3.3 MINERALOGICAL DOMAINING OF LOW GRADE AND NO GRADE ZONES USING AUTOMATED DRILL CORE LOGGING AT CADIA
LEADER: | |||
David Cooke | |||
TEAM MEMBER: | |||
Matthew Cracknell | |||
STUDENT: | |||
Laura Jackson | |||
COLLABORATORS: | |||
Ronell Carey, Ekaterina Savinova Mary Harris Anita Parbhakar-Fox | Corescan Newcrest Mining University of Queensland |
PROJECT SUMMARY
2019
Geoenvironmental characterisation at the earliest life-of-mine stages is critical for designing the most appropriate environmentally conscientious waste management strategies and storage facilities. However, geochemical tests typically used for predicting waste characteristics are texturally destructive, and therefore do not appropriately describe the geoenvironmental characteristics of the waste materials, and indeed how they might evolve regarding the role of secondary minerals in metal cycling within the surficial environment. In 2019, PhD student Laura Jackson developed and tested a field tool for determining AMD risk in drill core and for screening waste, as well as developing and testing hyperspectral and automated mineralogy assessment methods for kinetic leach columns. Laura’s PhD thesis will be submitted in Q2 2020.
2018
Geoenvironmental characterisation at the earliest life-of-mine stages is critical for designing the most appropriate environmentally conscientious waste management strategies and storage facilities. However, geochemical tests typically used for predicting waste characteristics are texturally destructive, and therefore do not appropriately describe the geoenvironmental characteristics of the waste materials, and indeed how they might evolve regarding the role of secondary minerals in metal cycling within the surficial environment. In 2018, PhD student Laura Jackson focussed on how the geoenvironmental domaining index (GDI) can be used with other data sets to enable robust waste classification with a new methodology proposed. The integration of Corescan and laser-ablation ICP-MS data was explored with results presented at the International Conference on Acid Rock Drainage (ICARD) in Pretoria, South Africa. Automation of the acid rock drainage index (A-ARDI) was developed and tested using samples from this project in a workflow designed by Matthew Cracknell with results published in the Geometallurgy special issue of Minerals. Laura’s PhD thesis will be submitted in Q2 2019.
2017
Geoenvironmental characterisation at the earliest life-of-mine stages is critical for designing the most appropriate environmentally conscientious waste management strategies and storage facilities. However, geochemical tests typically used for predicting waste characteristics are texturally destructive, and therefore do not appropriately describe the geoenvironmental characteristics of the waste materials, and indeed how they might evolve with regards to the role of secondary minerals in metal cycling within the surficial environment. This research has been developing new protocols by which different mineralogical techniques (e.g., hyperspectral mineralogy) and mineral chemistry analyses (e.g., laser-ablation ICP-MS) can be effectively integrated to allow for mineralogical, chemical and textural information pertinent to environmental characterisation to be obtained from intact-waste materials (i.e., drill core).
To date, the geoenvironmental domaining index (GDI) algorithm has been developed using Corescan data and allows for domaining of inherent neutralisation zones as presented at the 9th AMD Workshop, Burnie, Tasmania, in November 2017. In 2018, research will continue on improving geoenvironmental forecasting through automation of the acid rock drainage index using high-resolution drill core imagery.
2016
Prediction of acid mine drainage (AMD) at the earliest life of mine stages is critical for designing the most appropriate environmentally conscientious waste management strategies and storage facilities. However, geochemical tests typically used for predicting waste characteristics are texturally destructive, and therefore do not appropriately describe how AMD might evolve, or the role of secondary minerals in metal cycling in the surficial environment. This research is developing new protocols by which different mineralogical techniques can be effectively used and integrated to allow for geoenvironmental characterisation of intact-waste materials (i.e., drill core materials) to be efficiently performed, in terms of time and cost.
To date, method development has focussed on using Corescan™ data and drill core materials collected from the Cadia district, New South Wales. By undertaking a range of established static tests and conventional mineral identification (i.e., XRD), a geoenvironmental domaining index (GDI) tool has been developed using the hyperspectral data provided by Corescan™. GDI version 1 was fine-tuned to identify inherent primary neutralisers within low- or no-grade zones, so as to optimise their use when designing waste management strategies. A review of additional mineralogical tools to assist in refining estimates of sulfide abundance was also conducted, focussing on LA-ICPMS, micro-XRF, laser Raman and laser induced breakdown spectroscopy. Data processing indicates that LA-ICP-MS is the most appropriate technology to enable development of GDI version 2.
2015
Prediction of acid rock drainage (ARD) at the earliest life of mine stages is critical for designing the most appropriate environmentally conscientious waste management strategies and storage facilities. However, geochemical tests typically used for predicting waste characteristics are texturally destructive, and therefore do not appropriately describe how ARD might evolve and the role of secondary minerals in metal cycling in the surficial environment. This research is developing a protocol by which different mineralogical techniques can be effectively integrated to allow for mineralogical and textural information pertinent to environmental characterisation to be obtained from intact-waste materials (i.e., drill core materials, tailings as received).
Method development of these techniques has involved two site visits. A preliminary site assessment and geology study was undertaken during the first visit, while the second visit specifically focussed on using Corescan to gain hyperspectral data. Two hundred and forty-seven samples, representative of two major drill holes through the deposit, have been selected for the method development stage. Following the field campaigns, further analyses is being undertaken, including hardness testing, ARDI, UV fluorescence and carbonate staining. Following completion of these studies, 30 subsequent samples will be chosen for detailed mineralogical and geochemical analyses.