Open Cut » Environment
In early 2017project C25029 was successfully completed to investigate the use of LIDAR (Light Detection and Ranging) for operational dust control at open cut coal mining operations. The objective of this work was to investigate suitable options and implement a real time monitoring method that would provide accurate detection of PM movement across significant and critical sections of a site boundary, with the potential to be visualised in real time.
Such a demonstration could assist the coal mining industry (in particular open cut mining) by providing early detection of adverse PM movements across site boundaries. Real time information will enable the industry to better manage on site dust emissions, reduce unnecessary production stoppages and improve general air quality in the area.
The study outcomes to date suggest that LIDAR is suitable for use at mines and other industrial complexes for detecting PM plumes, evaluating the effectiveness of dust mitigation and control strategies and tracking of dust plume movement and dispersion at critical fence lines locations.
This project represents a collaboration with Dr Hashmonay, an international expert in the development and implementation of optical remote sensing (ORS) and other advanced air monitoring methodologies, to provide additional review of monitoring data gathered during project C25029 monitoring campaign. It has attempted to achieve a linear calibration curve between DT concentration data and relative extinction. In order to do this the following three critical considerations needed to be addressed:
- LIDAR inversion - corrected backscattering to extinction;
- Spatial reference - path integrated versus point;
- Time synchronisation- scanning versus fixed sampling.
Both fence-line and over pit LIDAR monitoring data from project C25029 monitoring campaign were used to attempt this calibration but only the fence-line monitoring was found to provide a good correlation. Additionally, since the completion of project C25029, there have been other examples of LIDAR use for dust management within Australia. Overview and commentary of those projects within the public domain is provided.
Finally, to address the critical considerations and any lessons learnt from reviewing recent Australian applications of LIDAR, a protocol for best practice deployment of LIDAR for dust management purposes was developed. The objectives of the proposed protocol and LIDAR system are to address all considerations in real time and provide the site managers the four pillars of emission monitoring:
- WHEN: alert when an outlier PM emission event occurs;
- WHERE: show the location within the site that the PM emission event originated;
- WHAT: classify the size categories of the PM emission event (e.g. PM10 and PM2.5); and
- HOW MUCH: quantify the PM emission event in term of mass of PM crossing the fenceline of the facility (eg kg/hour of PM2.5).
All of these aspects should be considered critical information to enable dust management in real time.