As the global demand for critical minerals rapidly increases, it is necessary to optimize their exploration and production to achieve the global transition towards a greener future. To meet this growing demand, the mining and exploration industry must adopt efficient exploration techniques.
A traditional post-drill exploration workflow consists of logging by a core logging geologist, followed by sending samples to an external laboratory for chemical analysis. Core logging is often performed by many different geologists, resulting in inconsistent interpretation and subsequent resource modeling. In addition, there is often a delay between sampling and receipt of results, which can then lead to further delays or sub-optimal decisions regarding drilling targets and exploration strategies.
In recent years, many exploration and mining companies have turned to the digitization of drill core using commercial drill core scanners to improve the speed and detail of logging and to better understand ore deposits. These core scanners have traditionally used near-infrared hyperspectral imaging (HSI), X-ray fluorescence (XRF), or a combination of both to provide mineralogical (in the case of HSI) and elemental (in the case of XRF) information in a relatively quick and affordable manner. While convenient, there are limitations to these technologies. Near-infrared HSI cannot identify metal oxides and sulfides, or quartz, as these minerals are not spectrally active. Species of carbonates and many silicate minerals cannot be distinguished from one another. XRF, on the other hand, is unable to detect light elements (Z < 13). Mg (Z = 12) and Na (Z = 11) can be detected but require longer dwell times that are not conducive to rapid core scanning.
ECORE, manufactured by ELEMISSION Inc., based in Montreal, is a fully automated, high-speed laser-induced breakdown spectroscopy (LIBS) commercial drill core scanner that is capable of detecting virtually every element on the periodic table (from H to U), which includes every element involved in the list of critical minerals. With ELEMISSION’s proprietary and easy-to-use LIBS CONTROL software and Smart Automated Mineralogy (SAM) algorithm, users have access to fast and accurate quantitative mineralogical and chemical assays within minutes (approximately five minutes per core box at standard resolution), allowing for real-time decision making. The versatile nature of ECORE technology allows analysis of various sample types (core, chips, pellets, pressed powders, rock slabs) with minimal sample preparation.
Massive Sulfide deposits
Understanding the mineralogy of a deposit is important not only to optimize production and planning for future extraction, but also for understanding controls on mineralization to facilitate exploration. ECORE’s use of LIBS technology allows for the direct detection of sulfide minerals, which typically host critical metals such as copper, nickel, cobalt, lead, and zinc. Since these deposits typically consist of greater than 40 per cent sulfide mineralization, the ability to differentiate these species and visualize textural relationships is critical. The selectivity of LIBS spectra allows users to distinguish between sulfide minerals of similar composition such as pyrite (FeS2) and pyrrhotite (Fe1-xS, x = 0 to 0.17), and iron oxide phases. Using ELEMISSION’s Smart Automated Mineralogy (SAM) algorithm, users can quickly generate mineralogical maps (Figures 1 & 2) to highlight different textures and mineralogical relationships for easy visualisation of mineralization behaviour within the core. Combined with elemental mapping, users can also determine mineral-elemental relationships, as well as compositional variations within minerals.
Lithium Pegmatite Deposits
Lithium plays a critical role in the global transition to clean energy. It serves as a critical component for batteries and increasing its supply is paramount to the current electric vehicle revolution. ECORE’s ability to detect light elements (e.g., Li, Be, Na, K, Rb) is extremely useful in the exploration of lithium pegmatites, as these elements are common in their mineral assemblages. The direct signal received from these elements also allows for the discrimination of minerals that are similar in composition. This can be seen in Figure 3, where using RGB mapping, spodumene, and petalite are easily distinguished from one another within the same core sample. Feature mapping like this has proven to be very useful not only for distinguishing between mineral phases but also for highlighting compositional variations within the same mineral. ECORE technology also has the added benefit of providing predicted and true chemical assays in real time, eliminating the weeks or months of delay that is typically associated with waiting for traditional laboratory assay. Figure 4 shows chemical assays taken at one-metre intervals over 1,500 metres of drill core from a lithium pegmatite deposit compared to assays obtained by a standard laboratory method (ICP-AES, four acids). The R² value (0.98) and the slope of the curve (0.99) show a very strong correlation between these two methods, demonstrating that ECORE is as effective and reliable as traditional laboratory methods.
ECORE revolutionizes the extraction and discovery of critical minerals by providing large amounts of information quickly, allowing for faster and more accurate interpretations to be made during the exploration, mining, and production stages. ECORE’s ability to detect almost any element on the period table minimizes the need for additional analytical methods, optimizing the entire exploration process.
