Chemistry of the drainage from a waste dump at BHP-Utah Mines Ltd, Island Copper mine

This thesis examines the chemistry of the drainage around the North Dump at BHP-Utah Mines Ltd., Island Copper Mine. It also presents the calculations of the pathway of water from precipitation and the acid generation and consumption of some areas on the North Dump. Information used in this study includes mine site fresh water quality monitoring records, acid-base accounting results of the North Dump drilling samples, flow rate measurements of drainage streams around the North Dump and of pit dewatering, physical parameters of the North Dump, surface topographical maps, meteorological records, etc. It has been found that a typical contaminated drainage has a total ionic strength of 0.0426and that the activity coefficients of the dissolved species in consideration depart markedly from unity. Most dissolved species are found to be under-saturated with respect to their most insoluble compounds, although over-saturation also exists. Levels of dissolved species are controlled by their rates of release and the frequency and amount of precipitation. Redox reactions and solubility control are investigated. Chemical reactions involving minerals present in the waste rock are considered in view of their effects on acid generation or consumption and on release rates of dissolved species. Eh-pH diagrams and solubility diagrams are constructed at conditions specific to the drainage under study.Applied Science, Faculty ofMining Engineering, Keevil Institute ofGraduat