Mine sites have many requirements for geophysics other than for exploration. Mine site geophysical investigations can contribute significantly to efficient mine operations, protection of the environment and safety of staff. Fender have extensive experience working in and around mine site and can provide a range of survey techniques to assist with mining operations.
Integrity of Tailings Dams and Leach pads
Tailings dams are embankments used to store waste from mining operations. This waste can be in the form of liquids, solids, or fine particle suspensions. Leach pads are similar to tailings dams but hold rocks for in-situ mineral extraction. Resistivity and electromagnetic studies can be used during feasibility studies to understands subsurface distributions of rock and soil and make assessments of risk due to subsidence. Ongoing monitors of tailings dams and leach pads are required to understand dam integrity and identify leakage in pond liners. Resistivity and electromagnetic studies can also contribute significantly to understanding locations leakages while pXRF can provide early assessment of contaminant concentrations.
Identifying groundwater sources
Mining operations require water for their operation but generally wish to limit groundwater ingress into the mine itself. Excessive groundwater within mines can damage capital equipment, lead to groundwater pollution and in extreme circumstances loss of life if ingress is sudden and unexpected. Resistivity and EM remain the mostly widely used survey techniques for mapping distributions of groundwater, however, seismic refraction can also be used to identify palaeochannels in bedrock which may contain groundwater.
Detecting historical underground mine workings
Mining activities for some commodities have histories going back 100’s of years. Understanding the distributions of these historical mine workings are an important safety concern. A modern mineral exploration strategy can include revisiting historical mine workings and undertaking further drilling and surveys. A poor understanding on historical underground tunnels could lead to loss of capital equipment or loss of life if drilling or excavation is undertaken nearby. Likewise, historical underground tunnel can occur in close proximity to modern urban centres and need to be well mapped to unsure safe urban expansion and safety of citizens. Resistivity is a proven technique for mapping tunnels from historical mine workings.
Determining rippability of rock and overburden thickness
Considerable amount of rock material may need to be excavated before the start of any new mining operations. Seismic refraction and MASW are primary techniques for mapping overburden thickness and rock rippability. Both variables are important for estimating costs for any large-scale excavation such as a new mine.