Conference Agenda

Many abandoned mine sites in Cornwall, UK, are characterised by elevated concentrations of arsenic (As), which can cause contamination of surrounding soil and water resources. These sites have important historical value that requires access to be maintained, despite exposure of humans to toxins that may lead to health issues including hyperpigmentation keratosis (including skin cancers) and liver fibrosis. The abandoned mine tailings at Wheal Maid has been assessed for As-bearing mineralogy and stability taking into account the public footpaths made by the local council to areas of potential contamination.

The paper investigates the mobilization of environmentally hazardous elements from loparite ore concentration tailings when exposed to atmospheric precipitation. A sulfuric acid solution simulating acid rain and distilled water were used as model solutions. When exposed to a weak sulfuric acid solution, a manifold increase in the decomposition rate of the tailings was observed. The concentrations of non-ferrous metals in the resulting solutions, when the test material was moistened with an acid solution, many times exceeded the maximum permissible concentrations for fishery water bodies. An intense transfer to the solution of rare earth elements was observed.

The River Almond catchment contains coal, oil shale and ironstone mine waste and displays widespread surface water metals pollution. Mineralogical investigations and geochemical modelling at four mine waste sites identified pyrite oxidation and jarosite, siderite and aluminosilicate dissolution reactions as the primary sources of metal pollutants (Fe, Mn, Al). Carbonate dissolution reactions control drainage pH. Pyrite is absent in burnt oil shale waste, however, trace content in unburnt shale horizons is implicated as a source of Fe in drainage waters. Site specific water quality and load assessments indicate pyrite bearing coal and ironstone sites present the greatest water environment risks

The study investigated the concentration of heavy elements in ground water and process water from the tailings of a uranium mine in Namibia. Inductively Coupled Plasma Mass Spectrometry was used to evaluate the concentration of heavy metals. Tailings water had higher average concentration of elements compared to ground water. The concentration of uranium in the ground water was above 15 µgl-1 and 30 µgl-1 as set by WHO and USEPA This shows that the ground water near the uranium mine is toxicologically not fit for human consumption.

Around 100 piles of waste rock are located in the Kizel coal basin, Western Urals, Russian Federation. A lot of metals and metalloids are transported with drain water from waste piles to soil, groundwater and the nearest river systems and pollute them. We studied the capability of industrial alkaline wastes, covered waste rock piles, to neutralise drain water, formed during rainfalls. The most effective alkaline reagent for drain water neutralization was soda plant’s waste. The investigation revealed that organic substances addition increased the efficiency of waste rock piles treatment with alkaline wastes used.