Mercury vapor sensor for alumina refinery processes

The sustainability of bauxite mining and refinery practices is reliant on attempts to reduce the environmental impacts of traditional processes. Mercury reduction targets set by industry and regulators has spurred attempts to develop technologies for evaluating the efficiency of mercury removal processes. The development of a mercury sensor suited to alumina refineries will be a significant breakthrough in controlling mercury emissions, as well as having many other applications. Gold coated Quartz Crystal Microbalance (QCM) based sensors employing enhanced nano-structured surfaces have been developed which show a substantial increase in response magnitude of at least 67% over non-modified QCMs. Additionally, the Hg-Au sticking probability calculated from the QCM data of the modified and non-modified sensors showed increased Hg affinity for the modified sensor. Furthermore, the modified QCM sensor was found to have better repeatability and stability while having 47 fold lower drift at the higher operating temperature, when compared to its non-modified counterpart.