Gold mining company AngloGold Ashanti earlier this year acquired a high-tech laser monitoring system from laser measurement technology and software supplier 3D Laser Mapping for use at its Geita gold mine, in Tanzania.

The system, SiteMonitor, provides the mine with data sets for analysis, enabling the mining company to predict potential slope failures and implement preventive measures to avoid loss of life and equipment damage, 3D Laser Mapping mining product specialist Steve Cairns tells Mining Weekly.

“The laser scanning system, which includes a long-range Riegl VZ1000 laser scanner and SiteMonitor software, scans pit slopes and acts as an early-warning system to determine any instability or movement that could potentially lead to slope failures or wall collapses,” Cairns explains.

The SiteMonitor system is specifically suited to mining applications, as it offers the required measurement range and its waveform analysis allows for the removal of vegetation and wire mesh from hanging walls, which is an important requirement for slope stability monitoring, he says.

Further, the waveform analysis also achieves superior performance and accuracies of measurement, even under adverse weather conditions. The Riegl VZ1000 scanner achieves accuracies of 5 mm at ranges of up to 1 400 m and can capture up to 122 000 points a second with a 100º × 360º field of view.

“The Riegl VZ1000 scanner is also equipped with a global positioning system unit that allows for rapid scan acquisition, automated scan registration, break-line extraction and mesh or triangulated irregular network creation.

“One superb feature of SiteMonitor is that the data captured for monitoring can also be used for production purposes, such as volume calculations, as the data sets are stored in native Riscan Pro or RiMining files. No georeferencing is required as these data sets are already on the correct coordinate system,” Cairns explains.

He adds that scans of areas of interest to production personnel can be scheduled or done on an ad hoc basis.

3D Laser Mapping has a telephonic support system in place for its clients, combined with remote access to the installations.

“This is part of the maintenance agreement and is designed to enhance the end-user’s experience. However, once a permanent monitoring station has been commissioned, limited interaction is required. It is designed to be an automated process, with periodic interaction mainly focused on checking system stability and data quality,” Cairns notes.

About 20 mines are using SiteMonitor software, with some sites having more than one scanner in operation, he concludes.