Problem 1
The "Trelogan" tailings" occurs at a calcareous lead/zinc deposit in Britain and has properties as shown below. \begin{tabular}{|lr|} \hline Particle size & \(\times\) \\ \hline\(>2 \mathrm{~mm}\) & \(6.7\) \\ \(2.0-0.2\) & \(14.6\) \\ \(0.2-0.02\) & \(29.7\) \\ \(0.02-0.002\) & \(24.8\) \\ \(0.002\) & \(24.2\) \\ \hline \end{tabular} Total analysis/\mug \(\mathrm{g}^{-1}\), \begin{tabular}{lr} \(N\) & 126 \\ \hline\(p\) & 160 \\ \(K\) & 1070 \\ \(C a\) & 138500 \\ \(M g\) & 1500 \\ \(F\) & 185 \end{tabular} Describe the nature of any expected physical and chemical problems associated with revegetation of these tailings, and how the problems might be overcome.
Problem 4
if the acidic leachate from sulfide tailings flows in a stream along the surface of the land, it is frequently observed that a red-brown deposit is found downstream on the rocks or sediment in the stream bed. Discuss the chemistry that might explain this observation.
