Using sUAS to evaluate lifespan of mining waste sites

Using sUAS to evaluate lifespan of mining waste sites

Companies have been mining nickel-copper ores in the northern region of Ontario, Canada since 1901. For this project, the Aeryon SkyRanger sUAS was used to collect imagery from a Tailings Pond and a Slag Heap. This imagery and data would then be used by the mining company to help evaluate the growth of the waste sites and determine next steps in the company’s growth strategy.

The flights were conducted over a day and a half with a mix of sun and cloud, temperatures 50º to 77º F (10º to 25º C), and winds between 9 – 15 mph (15 – 25 kph).

INDUSTRY: Commercial Inspection | REGION: Canada

APPLICATION

Tailings Pond

Tailings ponds are created to store waste from the mining extraction process. A tailings pond has a finite lifespan. The objective of this project was to use the aerial data to reflect the pond’s current footprint and compare to previously collected data. The comparison would then help determine how quickly the footprint has changed over time and how close the pond is to reaching its maximum capacity. This information would also be used to plan when to increase the size of the dam or area of the pond.

Tailings Pond

Slag Heap

A slag heap stores waste from the mining extraction process that cannot be easily separated. The slag heap also has a finite, planned, lifespan. The mine will compare the latest footprint of materials to a previously created orthomosaic map to determine how to optimize the future placement of extracted materials and estimate the rate of expansion since data was last collected. The output of the collected imagery will also be used to predict when longer term expansion (and large expenses) will be needed to further develop the site.

Both waste sites are well into their lifespan, and having the ability to monitor their rate of expansion enable the preparation of large expenditures and additional planning needed for each site. This will allow the mine expand only when necessary to avoid unnecessary expenses. In order to reduce the risk to the natural environment and ensure compliance with regulatory requirements, they must also ensure any expansion occurs before the current site is too full.

Slag Heap

REQUIREMENTS

The objective of this project was to demonstrate that the aerial imagery could be collected at a lower cost than a manned helicopter, and that the SkyRanger:

  • Provides high resolution geo-tagged photos and video
  • Enables the creation of accurate orthomosaic outputs for further analysis
  • Does not interfere with normal operations of the mine
  • Does not negatively affect the local wildlife

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This project was a great way for the mining company to trial how best to use UAS technology at the site”, commented Carley Hopkins, Product Manager, Aeryon Labs. “To consistently collect highly accurate data, without disrupting normal activities, will help with planning and overall efficiency of the mine’s operations.”

SOLUTION

Mapping the Site

The SkyRanger was launched from the road leading into the slag heap. The Aeryon HDZoom30 imaging payload was used to autonomously capture overlapping 20MP images at an altitude of 312 ft (95 m) above the take-off location. Multiple flight plans were used to collect the data at the two different sites.

After the flights were completed the project team retrieved the geo-tagged images from the SD card located in the aircraft and used Pix4Dmapper, image processing software, to create orthomosaics for each site.

A Digital Surface Model (DSM) and contour lines from the data enabled the team to analyze and compare the data to previously collected information using ArcGIS mapping software.

Tailings Pond Flight Plan

Tailings Pond Flight Plan - MCS

KEY BENEFITS

The SkyRanger platform proved to be the ideal solution for this mining application and provided:

  • Repeatability: Flight plans were saved and repeated to ensure consistent data collection over time
  • Ease of use: Automated flight planning tools in the SkyRanger Mission Control Station (MCS) software enables the pilot to focus on the job at hand
  • VTOL platform: Enables take-off/landing in confined or hard-to-reach areas 107 sq. ft. (10 sq. m) or less
  • Safety: Automated safety checks and sensors continually monitor the status of the aircraft, including wind speed, system temperature, and battery life
  • Reliability: Operations can occur in extreme environmental conditions
  • Cost efficiency: Normal mining operations can occur and a helicopter crew is not required

RESULTS

The output of the mapping project enabled the mining company to:

  • Optimize the placement of waste materials
  • Determine the rate of expansion of the site
  • Plan future growth at each site

Tailings Pond Output Data

Data collection area43.6 acres/17.7ha
Number of Images206
GSD (Average Ground Sample Distance)1.96cm/0.77in
Flights2
Tailings pond - mosaic
Tailings pond - DSM

Slag Heap Output Data

Data collection area110 acres/44.5 ha
Number of Images710
GSD (Average Ground Sample Distance)2.01cm/ 0.79in
Flights8
Mosaic
DSM