Sampling is one of the fundamental processes to characterize a mineral deposit, and is done in several stages of the evaluation and exploration of a mine. However, in order for important decisions to be made quickly, it is necessary that sample results are made available efficiently, especially in remote ventures where transportation can be an obstacle.
In order to minimize these problems, DMT Group, together with other partners, developed Ancorelog, an analytical core scanner system where results can be obtained in real time, through a state-of-the-art artificial intelligence system. Algorithms transform measured properties ("big data") into geological, geotechnical, and geometallurgical properties ("smart data"), on the spot, and in real time.
Because it has a modular design, Ancorelog can be equipped with different sensor combinations. The available sensors measure: the chemical and mineralogical composition of the rocks, as well as the lithologies and alteration zones.
Due to its compact design, Ancorelog can be used both in the field and in laboratories. In addition, the device has passed the health and safety requirements that European regulatory agencies impose on these devices before they can be used in the field.
How does Ancorelog work?
Machine learning algorithms make precise measurements of the concentrations of the chemical elements on the surface of the sample, weighting and interpolating to its total volume.
The physical, chemical and mineralogical properties of the samples are measured at a scan rate ranging from 20 seconds to 2 minutes, per meter of sample. The rate varies depending on the sensitivity and combination of the sensors used.
The Ancorelog is designed to process samples with a maximum length of: 125 cm long, 50 cm wide and 15 cm in diameter. A laser sensor first scans the surface of the samples and determines an optimal measurement path for each of the sensors. Sensor measurements are performed individually and sequentially in an automated process, and can reach a scan rate of 20 to 60 meters per hour, depending on the combination of the sensors and the accuracy of the measurements.
Data from different sensors is compiled, merged, and stored in CoreBase (analysis and database software), which offers online accessibility and a collection of sample data on a digital registration page.
The following sensors can be combined in Ancorelog:
- High-resolution RGB line scanning camera (up to 60 pixels/mm);
- Hyperspectral Imaging Camera (SWIR) with FRX sensor and control software: ANCORELOG;
- RAMAN sensor with timegate;
- Laser profile scanner.
High-resolution RGB line scanning camera (up to 60 pixels/mm) / SWIR hyperspectral camera for lithological/mineralogical characterization.
Imaging spectroscopy is a technique that identifies minerals through their absorption and reflection characteristics at specific wavelengths in the electromagnetic spectrum. The near-infrared (VNIR) region (0.4 to ~1 um) allows discrimination of Fe-oxides and oxyhydroxides in base metal deposits, while the shortwave infrared (SWIR) region (~1 to 2.5 um) contains diagnostic features associated with the absorption of vibrational energy in the crystal lattice, allowing discrimination and mapping of distinct minerals or clusters of minerals commonly associated with hydrothermal alteration zones around gold and metal deposits Basic.
Ancorelog features a high-resolution RGB scanning camera (60 pixels/mm or 1270 dpi). In addition to hyperspectral imaging cameras with wavelengths from 400 to 25000 nm. The RGB line scan camera and hyperspectral cameras perform a sequential scan on all samples, allowing for high spatial resolution, causing images to be automatically generated to match the analysis.
The Table below shows in which region of the infrared spectrum (VNIR/SWIR) different minerals are detected:
| Mineral | VNIR | SWIR |
| Actinolite | – | + |
| Diopside | + | +/- |
| Elbaite | – | + |
| Grossular | +/- | – |
| Forsteritis | + | – |
| Epidote | – | + |
| Muscovite | – | + |
| Clinochlore | – | + |
| Illite | – | + |
| Kaolinite | – | + |
| Calcite | – | +/- |
| Dolomite | – | +/- |
| Gibbsite | – | + |
| Alunite | +/- | + |
| Gypsum | – | + |
| Borax | – | +/- |
| Apatite | +/- | – |
| Hematite | + | – |
Example of minerals detectable through the hyperspectral camera – Source: DMT.
The use of hyperspectral imaging in Ancorelog is not limited to mineral detection and mapping. Neural networks are trained to identify different classes of interest, for example: lithologies and zones of change. The neural network can also be adapted to identify certain mineralogical compositions, representative of lithologies or alteration zones.
XRF spectrometer/LIBS scanning system for semi-quantitative chemical analysis.
The X-ray fluorescence sensor can be modularly equipped with a Timegated Raman sensor for mineral identification, as well as a plasma spectroscopy technology for the measurement of chemical composition as a complement to the X-ray fluorescence sensor.
The XRF sensor continuously scans along the central axis of the drill core, integrating the measurement results over a variable period. In addition, the measurement ranges can range from 1 to 100 cm, unlike handheld XRF devices.
Similar to the XRF sensor, the LIBS sensor can measure continuous profiles in the drill core and add detailed maps of the distribution of elements on the sample surface.
By combining the images with the XRF measurements, a classification model based on machine learning algorithms can be automatically trained by geologists to identify lithologies, change zones, and the chemical or mineralogical composition.
Raman sensor with timegate for mineralogical characterization (T-REX project).
The T-REX is a Raman sensor with time control that can be integrated into Ancorelog's logging system.
Timegated Raman technology brings a significant improvement to Raman technology, allowing for fast and accurate mineralogical analysis of samples, as well as being applicable to a wide range of minerals, including critical minerals such as lithium. The mineralogical composition data collected through the T-REX sensor joins the data from Ancorelog's various sensors and has enhanced the intelligent algorithms designed to classify the samples into geological and geometallurgical domains.
Due to Ancorelog's automatic scanning process together with an automatic roller conveyor, the instrument can handle the daily samples of ongoing projects and also analyze large volumes of core cores.
Minerals detectable by Ancorelog include: apatite, fluorite, garnet, gypso, k-feldspar, microclimate, muscovite, quartz, plagioclase, talc, tantalite, wollastonite, zircon, sphalerite, calcite, molybdenite, magnesite, tourmaline, hematite, serpentine, graphite, spodumene, chlorite, dolomite, chalcopyrite, beryl, pyrite, pyrrhotite, chromite, lepidolite, halite, kaolinite, hornblende, magnetite, biotite, pentlandite, and galena.
Project partners:
- DMT Group;
- Timegate Instruments;
- Teknologian tutkimuskeskus VTT (Technical Research Centre of Finland Ltd. VTT);
- Águas Teñidas SAL Mines;
- KGHM Cuprum sp. z o.o;
- Centrum Badawczo-Rozwojowe (KGHM Cuprum Ltd. Research & Development Centre);
- LTU Business AB;
- Université de Liège;
- Bundesanstalt für Geowissenschaften und Rohstoffe (BGR).
Ancorelog is partially funded by EIT RawMaterials.
With accurate and consistent results in near real-time, Ancorelog contributes to rapid decision-making in the exploration and valuation of deposits. Qualitative data also allows a significant improvement in geological deposit models and can therefore significantly increase the planning and exploration of a mineral enterprise.
You can check out other products and more information on the DMT website. We commented on our blog about another DMT product, the CoreScan. You can check out the text on our blog, just click here.
Bibliographic sources:
https://www.dmt-group.com/ancorelog-1.html
Mining Türkiye Journal 16th Edition.