Rate controls on the chemical weathering of natural polymineralic material. II. Rate-controlling mechanisms and mineral sources and sinks for element release from four UK mine sites, and implications for comparison of laboratory and field scale weathering studies

摘要: Abstract Predictions of mine-related water pollution are often based on laboratory assays mine-site material. However, many the factors that control rate element release from a site, such as pH, water–rock ratio, presence secondary minerals, particle size, and relative roles surface-kinetic mineral equilibria processes can exhibit considerable variation between small-scale experiments large-scale field sites. Monthly monitoring mine effluent analysis natural geological material four very different sites have been used to determine sources sinks for major elements contaminant metals Zn, Pb, Cu. The are: coal spoil tip; limestone-hosted Pb mine, abandoned last 200 a; mine; slate-hosted Cu was 150 a ago. Hydrogeological these has performed allow fluxes suitable comparison with results be calculated. equilibrium common at sites, far more so than in studies. This is attributed long residence times low ratios high storativity formation soluble minerals efficiently adsorb onto their surfaces provides large potential source pollution. released rapidly if conditions change significantly, in, example, case flooding or disturbance.