The closure of mine processing and waste disposal facilities is both a regulated activity and a potential source of corporate liability. All facilities must be designed and operated to satisfy relevant environmental regulations; however the authors' experience in preparation, submittal, defense and obtaining regulatory approval for implementation of closure related activities indicates that few are designed, and even fewer operated to facilitate closure. This paper discusses both the conceptual framework for closure oriented design and operation, and several specific design and operational elements that are key to characterizing closure components, and providing data that can be used to defend closure design and implementation.
These guidelines describe the process that must be undertaken when a proponent is considering using a natural water body frequented by fish as a Tailings Impoundment Area (TIA) such that a regulatory amendment to the Metal Mining Effluent Regulations (MMER) would be required. In the context of these guidelines, the term, TIA refers to a natural water body frequented by fish into which deleterious substances (such as tailings, waste rock, low-grade ore, overburden, and any effluent that contains any concentration of the deleterious substances specified in the MMER, and of any pH) are disposed. The requirements for the conduct of alternatives assessments that are presented in Part 2 provide useful guidance for the assessment of all mine waste disposal areas including those developed on land. The overall objective of the alternatives assessment process is to minimize the environmental footprint of the disposal area.
?Inspired by the success of cemented paste backfill in the west orebody of Chambishi Copper Mine, integrated disposal of paste backfill and surface high-concentration tailings stacking was applied in the southeast orebody. This paper presents the integrated disposal system, including two deep cone thickeners, double-shaft horizontal mixer, two plunger pumps for underground backfill and three diaphragm pumps for surface stacking. The challenges of the integrated disposal system were deep backfilling (0.98 km) and long-distance discharging (15 km), so a combination of gravity flow and pumping was used in paste backfill and three diaphragm pumps with a preset pressure of 7 MPa were applied for surface stacking. The annual ore production in the southeast orebody is 3.3 Mt, which is 3.3 times larger than that of the west orebody. Therefore, the capacity of the integrated disposal system also needs to be expanded. The capacity of the paste backfill system and surface stacking system were 160 m3/h with paste concentration of 75 wt.% and 265 m3/h with slurry concentration of 55 wt.%, respectively. In the first phase, the cement to tailings ratios for primary and second stopes are 1/8 and 1/24 respectively. To meet the backfill strength and reduce the cost, waste rock will be added in paste backfill in the second phase, the waste rock to tailings ratio is 1/3, the cement to tailings and waste rock ratio for primary stopes are 1:12, and 1:30 for secondary stopes. As a result, the UCS after 28 days for primary and second stopes were 1.2 MPa and 0.5 MPa, respectively.
This handbook addresses the theme of tailings management in the Leading Practice Sustainable Development Program. The aims of the program are to identify the key issues affecting sustainable development in the mining industry and to generate information and case studies that illustrate a more sustainable basis for mining operations.
The Tronox KZN Sands Fairbreeze Mine is located in Zululand, south of Mtunzini on the east coast of South Africa. Mining activities commenced in 2015 and the declared life of the mine is 15 years. Fairbreeze Mine is beneficiating an orebody that is part of the Berea Red dune system and the fines content is known to approach 30% in some areas of the deposit. The definition of fines in the mineral sands industry is classified as any particle passing 75 µm and consists predominantly of clays and some traces of silica particles of silt size. Historically, the mining industry has made use of sub-aerial deposition to dewater fines that do not drain freely. The only tools available to the processing facilities using the sub-aerial deposition dewatering method, has been: In order to minimise the risk and to reduce the sterilisation of large tracts of land, mining companies are being forced to consider alternative dewatering techniques. The use of amphibious vehicles, or mud-crawlers, is a well-documented alternative in the alumina industry but little is known about the performance of amphibious scrollers on mineral sands fines residue. This paper investigates the effects of mechanical scrolling performed by mud-crawlers on the dewatering and the ultimate final dry density of Fairbreeze fines. The investigation looks at ways that mud-crawlers can be applied as a financially viable alternative to sub-aerial deposition.