ICARD-IMWA 2015 is organized to provide an international forum where mining professionals, operators, researchers and suppliers can meet to exchange, interact, analyze and discuss experiences and recent innovations in the area of sound and responsible mine water and effluent management. These proceedings contain 220 abstracts of papers and posters written by authors from 24 countries. The main topics addressed by the abstracts included in these proceedings are: Geomicrobiology, biogeochemical cycles and biomining; Applied mineralogy and geoenvironmental units; Prediction of drainage flow; Prediction of drainage chemistry; Mine water and drainage collection and treatment; Cover design and performance; Scaling from laboratory to field studies; Reliable mine waste management; Reliable mine water operation; Mine dewatering; Mine water management for closure; Mine water geochemistry and Pit lakes.
Since 2005, the ACG has published conference papers across the geotechnical mining spectrum, including: underground and open pit mining, paste and thickened tailings and mine closure. The repository aims to provide the mining geomechanics fraternity with open access, peer-reviewed conference proceedings that may assist readers to maintain and develop their skills, knowledge and capabilities.
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.
?Hindustan Zincs Rampura Agucha Mine is a world class orebody that has successfully transitioned from an open pit operation to an underground sublevel open stoping with paste backfill operation. The mine currently has two identical paste plants that each can produce between 160-185 m3/hr of cemented paste backfill. Plant #1 was commissioned in 2014 and plant #2 was commissioned in 2019. The two plants are equipped with Putzmeister piston pumps that pump from the plant to the edge of the pit, down a borehole to the North and South main ramps and then down the ramps to the top of the underground orebody approximately 500 m below surface. Each plant was designed with an operating and standby paste pump. Most of the orebody can be reached from these main lines, however, at the extreme north end of the pit, there is portion of the underground orebody that is above the uppermost underground delivery level and at a significant horizontal distance from the main paste trunk lines. Because of the location of these northern stopes, an overland pipeline to the north of the pit is required before entering a borehole down to the stoping levels. This lateral distance on surface and underground would have resulted in very high pressure on the paste pumps, and a decision was made to temporarily install the standby pump from plant 2 at a booster station that would allow the northern stopes to be reached with a 2 stage pumping system instead of a single stage pumping system. The booster station was installed and commissioned in 2019 and this paper discusses the design principles regarding booster stations in general as well as the specific design, commissioning, and operational experiences with the booster station at Rampura Agucha Mine.
In the present study, laboratory experiments were performed to investigate the geotechnical properties of four different tailings, including two iron tailings (coarse and fine) and two copper tailings (coarse and fine).
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.
In the early 1960s, a series of field instrumentations were initiated by the US Bureau of Mines on hydraulic fill. These studies were conducted in order to better understand the characteristics of hydraulic backfill. Cemented paste backfill (CPB) has gained wider acceptance in the mining industry and the number of operations utilising CPB has expanded significantly. One of the earliest attempts at field measurement in CPB occurred over 20 years ago. Since then, extensive scientific research has been conducted on CPB material in order to provide mines with a rational design process; however, there has been limited published instrumentation programs. The authors affiliated company has been involved with in-stope backfill instrumentation programs at numerous operations. Because of the data collection and field experience, the authors have a better understanding of how in situ backfill behaves, and how operations can use this information to safely improve the efficiency of their backfilling operation. In order to improve the safety and efficiencies of backfilling for other mines and other practitioners, a collection of published data along with additional case studies are provided. This paper summarises both hydraulic and CPB instrumentation results focusing on the important mechanical properties of backfill: time to onset of effective stresses and hydrostatic loading (i.e. fluid backfill to soil?like material), influences of flushes, thermal expansion and contraction, and influences of seismic and blast events.
?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.
Cemented paste backfill (CPB) has been utilised globally in mines based on its benefits of non-segregation, non-bleeding and homogeneity. Due to a lack of research around the mechanism(s) driving anti-segregation properties, nowadays only some engineering empirical parameters including the slump or the fine particle content of backfill slurries can be used as the descriptive criterion for CPB. To better understand the antisegregation mechanism of CPB, so a quantitative criterion for its identification can be determined, the segregation-induced inhomogeneous properties of cemented tailings backfill have been experimentally investigated. Samples (diameter 75 mm and height 150 mm) with different solid contents were poured, cured and cut into sections of equal height. Thereafter, titration measures of EDTA-2Na and helium porosimeter have been used respectively to test the cement content and porosity of each section. Results show that the cement contents decreased from top to bottom along the curing height of samples, while the porosities increased along the settling direction. The inhomogeneity of cemented samples is affected obviously by the solids content of the paste, and it is notable that there is a turning point for the slurry concentration value over which the homogeneity will be improved dramatically. The turning point could be used as a new criterion for CPB definition from the perspective of inhomogeneity inhibition.
Repository of sources (projects) under the Mineral Resources Program. Objective: Understanding potential and existing environmental impacts of mineral resources and their extraction promotes sustainable development of needed mineral materials and responsible stewardship of our natural resources. Topics include baseline data, bioavailability, deposit models, geochemistry, metal mobility, metals in waste, mine waste, mineral resource formation.