Validation of NeutraSeal: A new lower energy cost mine water treatment process

The results of pilot-scale tests of a new lower energy cost acid mine water treatment process ‘NeutraSeal’ are presented. NeutraSeal is similar in principle to standard high density sludge systems but harnesses a static head of water to lower pumping costs, and introduces optimised neutralisation and aeration. From pilot-scale tests at an abandoned mine in Cornwall (2013), the process showed a >50% reduction in energy consumption compared with similar conventional systems. This energy saving was for an equivalent water treatment performance, the process reducing the concentrations of Fe, Zn, Cu and Mn by over 95% and Cd, Ni, Al and As by over 80%, to levels within discharge consents set by the Environment Agency for the neighbouring Wheal Jane Mine Water Treatment Plant. Additional benefits of NeutraSeal include >30% lower capital costs, the system is scalable with the capacity to treat flows of up to 2000 m3/h, is modular and has a reduced footprint, typically 60% the size of conventional plants. The sealed nature of NeutraSeal expands the range of operating geographies, with increased reliability in extremely cold environments and reduced water loss in hot climates.