Identifying the mineralogy in geological samples is a primary objective and foundational component across the geoscientific disciplines of the exploration-mining-geometallurgy-remediation chain.
Spectral Geoscience use the TSG software and infrared spectroscopy as tools to extract qualitative and quantitative mineral information from geological samples to support the objectives of exploration and mine geologists, geotechnical engineers, geometallurgists and environmental engineers.
Examples of applied hyperspectral-mineral results include:
- Rapid, non-destructive, real-time identification of your field sample’s mineralogy collected in early reconnaissance field mapping and trench sampling.
- Combine with GPS coordinates to produce geographically registered mineral (alteration) maps.
- Database-ready mineral results integrate easily with complementary exploration datasets and provide input to exploration and mineral system models.
- Real-time mineral results acquired in the field/camp facilitate timely decisions, reduces risk, expedites the generation, evaluation and prioritisation of new targets and drill hole planning.
drill core Logging
- Step-change and value-add to conventional core logging by introducing objective and consistent hyperspectral mineralogical logging of drill core or chips (i.e. overcoming the recognised issue of the variable quality and consistency from using multiple, often less experienced geologists to log core).
- Identify key alteration minerals, delineate their vertical and lateral spatial distribution, zonation patterns and overprinting relationships.
- Characterise the 3D physico-chemistry properties and architecture of a deposit based on the identification of minerals that form under specific temperature and pH conditions.
- Investigate mineral related spectral signatures that may help distinguish barren from mineralised intrusions and determine distal to proximal relationships (potential vectors) to the ore zone.
- Hyperspectral mineral results exported from the TSG software (.csv) provide database-ready, digital input for developing prospectivity models.
- Categorical (qualitative) or numerical (quantitative) mineral characterisation variables can be combined to form a prospectivity model representing spatially-favourable mineralogical associations with/to mineralisation in an ore deposit.
- Interpolation between samples or drill holes can be integrated with ancillary data and interrogated in a GIS or mine modelling package to highlight potential extensions to mineralisation.
- Use hyperspectral data collected from field samples to plan for and / or validate airborne and satellite-derived mineral maps.
- The high spectral resolution from field spectrometer data can be down-sampled to airborne and satellite-based wavebands and used to drive the processing of the data.
- Logging the mineralogy in blast hole chips improves objectivity and consistency in bench mapping and may define mineralogical parameters to support grade control.
- Interpolation of the mineral results between blast holes may indicate continuity or cessation of alteration; and changes in alteration intensity as a function of proximity to mineralisation may also support grade control.
- Mineral spectroscopy is a fast and cost effective analytical technique for the detection of swelling clays (e.g. montmorillonite) to aid geotechnical risk assessment and improve stability in mine design.
- Hyperspectral drill core logging of alteration mineralogy related to mineralisation provides soft boundaries on the spatial distribution of grade in resource modelling and an additional layer of evidence and confidence to support resource estimation.
- Hyperspectral logging contributes to ore body knowledge; supports assertions of continuity and the degree of connectivity between drill holes, and can indicate potential extensions of mineralisation into areas yet to be drilled.
MINE PLANNING & DEVELOPMENT
- Hyperspectral core logging enables the infrared-active mineral inventory of an ore deposit to be rapidly and consistently characterised into domains to assist with mine planning and development.
- Operational benefits come with improved understanding of the mineralogical characteristics of the orebody and surrounding gangue mineralogy that typically constitutes the bulk tonnage of a deposit.
- Mineral spectroscopy is often best suited to logging the dominating gangue minerals associated with sulphide deposits as most sulphides do not generate an unambiguous infrared spectrum.
- Hyperspectral core logging compliments grade, lithology and structural information in mine planning and development.
- Improvements in mine-mill accounting and reconciliation can be achieved by incorporating hyperspectral mineralogical core logging data into the mine model to reduce uncertainty.
- Applied examples include; stock pile designation, sorting and blending based on separating ore from gangue mineralogy; similarly over a conveyor belt sorting feed to appropriate crusher or mill.
- Provides strong links and input into subsequent geometallurgical flow sheet design.
- Hyperspectral core logging provides continuous down hole, macro-scale mineral results for input to characterise domains in geometallurgical block models and assist flowsheet design.
- Overcomes the industry recognised problem of insufficient sampling to adequately represent the variability across a typical ore body.
- Guides the selection of core samples for essential metallurgical test work (e.g. JKDWT, BWI).
- Complimentary to spatially discrete micro-scale point measurements (e.g. QXRD, MLA and QEMSCAN).
- Identification of deleterious minerals in metallurgical processes resulting in lower recovery (e.g. talc in froth flotation consumes large amounts of reagents; clay coatings reducing grinding efficiency).
- Identifies the nature and deportment of mineralogical impurities that dilute grade, for example, kaolinite, gibbsite and quartz in iron ore bodies that also incur smelter penalties.
- Delineates mineralogical spatial domains whose relationships with ore may indicate differing metallurgical processing requirements for optimal recoveries.
- Identifying these domains in advance can reduce energy consumption and improve an operations efficiency and ore recovery economics.
- Mineralogy can be used as a proxy to predict mine-scale physical processing performance.
- For example, comminution varies according to rock hardness that is largely controlled by the constituent mineralogy (and texture).
- Also, acid consumption is governed by the presence and abundance of acid consuming minerals such as carbonates.
- Mineralogically characterise heap leach pads, stream sediment samples, road spillage from trucks etc to prevent/mitigate/assess/monitor environmental impact and plan for environmental compliance.
constrain Geophysical interpretation
- Knowledge of the subsurface mineralogy enables geophysical interpretation to be constrained and improves the accuracy of reported results.