Technologies Related to Automated Mineralogy
Automated Mineralogy and solutions like the TESCAN TIMA-X provide valuable information not only about the mineralogical composition of geological samples, but also much more in-depth information about liberation and distribution of phases. One of the beauties of automated mineralogy is that data generated by the TIMA-X about your process can be fed directly back into the process environment to effect immediate process optimisation resulting in increased efficiencies. These increases in efficiencies can rapidly pay back the capital expense in the initial investment. There are several technologies related to automated mineralogy that we will discuss below.
There are numerous other analytical techniques that can compliment automated mineralogy, but none are as comprehensive. These include:
- X-Ray Diffraction (XRD)
- X-ray fluorescence (XRF)
- Handheld XRF
- MicroXRF Mapping
- Laser Induced Breakdown Spectroscopy (LIBS)
- Raman spectroscopy
Of these techniques XRD and XRF are the most important to automated mineralogy. Data from XRD analysis if used to develop the mineral library for your specific mineral deposit for use with automated mineralogical analysis. XRF is used to generate a bulk chemical analysis of your deposit and this data can be correlated with data from the TIMA.
Directly Related Technologies
X-Ray Diffraction – XRD
XRD is the traditional method for determining the minerals that are present in a sample as well as the quantity of these minerals. By comparing the Xray diffraction pattern obtained from the sample to known crystallography databases, the identity of the minerals is determined. Mathematical models such as Rietveld Refinement determine the relative quantity of the minerals present. XRD a bulk analysis techniques and can only determine phases that are present above about 1.0% concentrationXRD will provide the relative concentrations of various minerals within a sample, but it is unable to provide distributions, associations liberation maps or point analysis like the TIMA-X and as such is a bulk analysis technique. Unlike the TIMA, XRD analysis suffers when the mineral is not highly crystalline and is amorphous. In these cases XRD will under report the mineral present.
The TIMA is able to detect minerals present to 0.01% concentration. In addition to this is able to calculate where minerals exist on the solid solution series with the end members.
Most XRDs can be equipped with automated sample changers for increased throughput and efficiency.
XRDs are available in benchtop or floorstanding configurations e.g. the Rigaku MiniFlex and SmartLab respectively. Larger systems produce more flux and are able to measure samples faster and have a better chance of detecting trace phases.
Rigaku MiniFlex benchtop XRD
X-Ray Fluorescence – XRF
XRF spectrometers provide elemental analysis. There are two configurations of operation: Wavelength Dispersive (WD) instruments for best detection limits typically found in high accuracy and large through put analytical laboratories providing you with accurate determination of the grade of your resource. The other configuration of XRF is the Energy Dispersive (ED) instruments such as hand held XRF spectrometers which give a fast qualitative analysis using inbuilt factory calibrations. Simultaneous emissions are recorded for all the elements. XRF instruments provide a bulk analysis. Some configurations are able to offer spot analysis for elemental mapping.
Like XRDs, conventional XRF spectrometers are available in benchtop or floorstanding configurations e.g. Rigaku Miniflex and Primus series respectively.
Rigaku Supermini200 benchtop XRF
Other Related Technologies
Handheld XRFs operate on the EDXRF principle. They have the advantage that they are portable and excellent for exploration geologists who can generate data instantaneously when out in the field.
Systems like the SciAps X-series LIBS have a Geochem mode designed specifically for geological and mineralogical applications.
MicroXRF Mapping Systems
Systems like the Sigray AttoMap are able to perform XRF mapping. This type of instrument can generate elemental maps of samples to show chemical distributions. Higher end systems can do this higher levels of precision, accuracy and speed.
LIBS or Laser Induced Breakdown Spectroscopy is another elemental analysis tool. Using a laser, atoms are ablated from the surface. LIBS looks at these species.
With a similar sized form factor as the a handheld XRF, they also offer portability and instantaneous analysis. LIBS has the advantage that it can detect the entire spectrum of elements including light elements such as lithium.
Systems like the SciAps Z-series LIBS have a Geochem mode designed specifically for geological and mineralogical applications.
LIBS Core Scanner – Coriosity
The Coriosity from ELEMISSION is the first instrument of its type. Able to detect every elemt in the periodic table, the Coriosity can automatically map core samples with a spatial resolution of 50µm at a rate of 40cm2/sec.
Raman spectroscopy is a rapid, reliable and practical tool for exploration geologists. Systems like the Ramanview from Nanophoton can be used to determine the minerals present in a sample, although the relative proportions of minerals present is more difficult to determine. The advantage of Raman is that no sample preparation is required.