Thermal remote sensing for moisture content monitoring of mine tailings; laboratory study

Mining produces massive volumes of mine tailings that are deposited into large scale mine tailings impoundments. A key environmental objective of managing these large impoundments is mitigating fugitive dust emissions by monitoring and controlling moisture, because moisture directly affects the tailings' strength and the ability to apply dust control measures using motorized equipment. Therefore, understanding the spatial and temporal variations in moisture content for surface tailings is critical for characterizing dust susceptibility and trafficability. Remote sensing has been proven to be a useful tool for similar applications. This study utilized laboratory testing conducted on iron mine tailings to verify that: (1) a relationship exists between moisture content and strength for the surface of mine tailings, and (2) thermal remote sensing can be used to infer spatial variations in moisture content for surface tailings. Multivariate regressions were developed to identify the critical remote sensing and climatic variables, and evaluate their influence in remotely measured moisture content. For tailings samples collected from two different North American iron mines, regressions using sample temperature and ambient humidity were able to predict surface moisture content (R (super 2) >0.9).