Tailings Dam Surveys

Tailings consist of ground rock and process effluents that are generated in a mine processing plant. Mechanical and chemical processes are used to extract the desired product from the run of the mine ore and produce a waste stream known as tailings. This process of product extraction is never 100% efficient, nor is it possible to reclaim all reusable and expended processing reagents and chemicals. The unrecoverable and uneconomic metals, minerals, chemicals, organics and process water are discharged, normally as slurry, to a final storage area commonly known as a Tailings Management Facility (TMF) or Tailings Storage Facility (TSF). Not surprisingly the physical and chemical characteristics of tailings and their methods of handling and storage are of great and growing concern. Bathymetric survey of tailings dams is necessary because the dam floor levels beneath the water are constantly changing and the volume of water stored is therefore also changing. For dams used to supply processes the volume of water available must be known to support operations. The Teledyne OceanScience Z-Boat is a rugged and capable platform that is ideal for tailings dam surveys. The Z-Boat has the power to perform on large, wind-affected dams in choppy conditions and is easily configured to carry Single Beam Echo Sounder or other instruments for the survey as required. In operation the GNSS (GPS) rover on the boat provides accurate position and heading, and an echo sounder depth-finder simultaneously reports the depth under the boat; the combined dataset is transmitted to the operator on the shore in real time. This real time data display is used to assist the operator in guiding the boat along the survey route, which may be over 1500m distant from the shore. Echo sounders used may be basic units recording a single digital depth value under the boat, or complex echogram-enabled systems that provide advanced quality control checks of sounding data, with the applicability of each depending on local conditions and planned uses for the equipment at the site. The Z-Boat has proven successful at many mines, greatly improving water volume estimates and allowing detailed stage / volume relationships to be developed and maintained by repeat surveys with a previously impossible frequency. Health and safety outcomes are improved for operators as they can pilot the Z-Boat remotely and remain at a safe distance from risks such as caustic ponds.