Lightweight and field-portable devices are the most suitable for African mining conditions, as they enable exploration teams to easily navigate the mostly rough terrain, says field-portable ultraviolet, visible and near infrared spectrometer designer and manufacturer Spectral Evolution.

The company offers the oreXpress field- portable spectrometer for mining with EZ-ID software that provides real-time mineral identification for deposits including gold, copper, nickel, uranium, light-rare-earth-element- and heavy-rare-earth-element-(HREE-) bearing minerals, says Spectral Evolution president Dennis Witz.

HREEs include europium, gadolinium, terbium, dysprosium, holmium, erbium and yttrium.

Witz says HREEs are used in various high-technology and energy applications. “For instance, dysprosium is used for permanent magnets, europium for phosphors and fuel cells, terbium for phosphors and permanent magnets, and yttrium for red phosphor, fluorescent lamps, ceramics and metal alloys.”

Rare-earth-bearing minerals for HREEs can include monazite and xenotime – two phosphate minerals that are available in the spectral libraries of the oreXpress and EZ-ID, he adds.

Xenotime is usually found in acidic and alkaline rocks and occasionally in mica schists and quartz gneisses, Witz says, adding that monazite is associated with high-specific-gravity minerals such as ilmenite, magnetite, rutile and zircon.

Witz explains that the EZ-ID software allows for the fast and accurate identification of an unknown mineral, after comparing it to a library sample of known minerals. The software is easy to use and, collecting a target scan, results in immediate match results in real time on a laptop, says Witz.

In addition, the software has a simple and consistent user interface that can include or exclude spectral regions of interest for optimal results. It also enables quick scanning for optimum fieldwork or core shack logging, he says.

“With our Custom Library Builder software module, EZ-ID enables you to scan known samples and quickly build a custom library for a particular location, project and mineral. You can select predefined metadata fields or define your own,” explains Witz.

The spectrometer was released in 2013 for mining exploration and is distributed in South Africa by geospatial solution and aerial survey company Southern Mapping.

Witz says the spectrometer, which took a year to develop, delivers rapid data and spectra collection in the field, high-resolution scanning, a high signal-to-noise ratio for improved sensitivity and fast start-up. No optimisation step is required between scans and a sturdy construction makes it suitable for use in the field.

The device is reliable, with no moving optics and a robust metal-clad, fibre-optic cable connector with easy-disconnect fibre, as well as a rugged and reliable mineral contact probe for single-click field measurements, he explains.

Witz says oreXpress conforms to the CE mark – a mandatory conformity marking for products sold within the European Economic Area since 1985.

The oreXpress is being used by copper exploration company Luna Mining, in the Democratic Republic of Congo, Witz notes.