Abstract: Environmental desulphurization is an attractive alternative for acid generating tailings management as demonstrated during the last few years. In fact, such process placed at the end of the primary treatment circuit allows to reduce greatly the amount of problematic tailings by concentrating the sulphidic fraction. Moreover, the desulphurized tailings (non-acid generating) have the geotechnical and environmental properties for being used as fine material in a cover with capillary barrier effects. To produce desulphurized tailings, non selective froth flotation is the most adapted method as shown in many previous works. Desulphurization level is fixed by tailings sulphur content (or sulphide content) and neutralization potential NP. The final residue should have enough NP to compensate for his acid generating potential AP. In this paper, the authors present the results of laboratory tests conducted in Denver cells for studying the sulphide flotation kinetics of four mine tailings which are characterized by a weak neutralization potential (under 37 kg CaCO (sub 3) /t). Tailings 1, 2, 3 and 4 contain respectively 5.27, 10, 4.25 and 16.9 sulphur Wt. %. Tailings 1 and 2 are cyanide free and are well floated at pH around 11 by using amyl xanthate as collector. Collector dosage was optimized for these tailings and the results show that Tailing 2 need more collector. However, Tailings 3 and 4, which come from a gold cyanidation process, could not provide good sulphide recovery with xanthate collector because of the pyrite depression. To overcome this problem, amine acetate was used successfully but induces important entrainment. The consumption of this collector was also optimized. The results of kinetic tests and collector dosage were combined and modeled to establish relationships which allow to estimate the desulphurization performances.

Abstract: The mining industry has made tremendous strides in the last 20 years in the prevention and control of acid mine drainage. However, there remain a number of circumstances where the long-term operation, care and maintenance of tailings management facilities will be required. The application of progressive environmental technologies and management systems is key to cost control and environmental liability management at these sites. Mine Waste Management Inc. currently operates Rio Algom Limited's five effluent treatment plants and seven waste management areas in the Elliot Lake, Ontario region using a Remote Plant Monitoring and Control Network (RPMCN). This system, based on Intellutions's “Fix 32” technology, enables the monitoring and control of these plants from a centralized location thus reducing labour costs while providing 24-hour surveillance. Scheduling, auditing and reporting of plant operating and environmental monitoring programs are integrated and controlled using the Envista (super TM) environmental information management system. Proper application of these technologies and management systems facilitates delivery of cost-effective environmental monitoring, and care and maintenance programs at these sites and provides tools to demonstrate compliance with all environmental performance criteria.

Abstract: Acid mine drainage is recognized as a serious environmental issue at mine sites world wide. While sulphate and metal concentrations in acidic drainage can reach exceptionally high levels, these can also be elevated and of concern in neutral drainage from waste rock and tailings. “Neutral mine drainage” (NMD) has not yet received as widespread attention as acid mine drainage (AMD). The oxidation of sulphide minerals and the production of either acidic or neutral contaminated drainage is affected by many factors. This paper examines the specific factors that result in the production of “neutral mine drainage” from mine wastes. Several case studies are presented which involve predictive geochemical modelling to illustrate the possible time frame and magnitude of contaminated neutral drainage.