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Graphical pre- and post-processing for a two-dimensional boundary element code, including automatic mesh generation
Published in W.A. Hustrulid, G.A. Johnson, Rock Mechanics Contributions and Challenges: Proceedings of the 31st U.S. Symposium, 2020
J.M. Crotty Sisson, R.H. MacKinnon, A.N. Stokes
The capabilities of the pre- and post-processors are demonstrated using a cross-section of a stoping structure from a nickel mine at Kambalda, Western Australia. Three rock types are present - a barren ultramafic (R1), mineralized ultramafic (R2) and basalt (R3) - see Figure 2. The different rock types are separated by zones of shearing which are modelled as weak joints. The barren and mineralized ultramafics are modelled as the same material, with Young’s modulus (E)=36 GPa and Poisson’s ratio (υ))=0. 3, and E=45 GPa and υ=0. 28 for the basalt. Normal and tangential joint stiffnesses are 2 and 0. 7 GPa for the joint between the ultramafics, and 40 and 14 GPa for the mineralized ultramafic/basalt joint, respectively. All discontinuities have a friction angle of 20 degrees and zero cohesion and are assumed to possess zero tensile strength. A closure limit of 1 cm was assumed for the joint between the ultramafics and 1 mm for the mineralized ultramafic/basalt joint. Before mining the principal field stresses are 32 and 16 MPa, with the maximum stress orientated 30 degrees anticlockwise to the horizontal of Figure 2. The generated mesh of 700 vertices (Figure 4) produces 102 boundary elements and 600 interior points. Examples of graphical output generated for the case study are shown in Figures 5, 6 and 7. All stresses are in MPa and the displacements are in metres.
Seismic monitoring at Long Shaft in the Kambalda region — A case study
Published in T. Szwedzicki, Geotechnical Instrumentation and Monitoring in Open Pit and Underground Mining, 2020
Kambalda township lies about 50 km south of Kalgoorlie in Western Australia. The Western Mining Corporation mines are located around the township and extend to the Tramways area which is about 60 km further south. Three more nickel mines, associated with the Widgemooltha Dome, lie further south and west of Kambalda. The mine in question, Long Shaft, may be simplistically described as being a narrow ore body with a dip of about 70° east, between 300m and 850m below surface, and having a maximum strike length of about 1450m. The ore is usually sandwiched between a very strong basalt footwall and very weak ultramafic hanging wall. This unfortunate mixture of mechanical properties is further compounded by stiff porphyry dykes which cut across the strike of the ore through the hanging- and foot walls. Typical mechanical properties of the rock types measured in the laboratory are shown in Table 1. A major crustal shear zone, the Boulder-Lefroy Fault, lies less than a kilometre to the east.
Acid Rock Drainage
Published in Karlheinz Spitz, John Trudinger, Mining and the Environment, 2019
Karlheinz Spitz, John Trudinger
Sulphide oxidation, with or without subsequent leaching and drainage, may adversely affect mining operations in numerous ways, such as: Corrosion of concrete foundations, culverts, metallic pipes and walkways;In some open pit situations, such as the North Davao Copper Mine in the Philippines, sulphur dioxide fumes may be generated from the pit walls, which in the absence of ventilating winds, may settle in lower parts of the pit, presenting a hazard to the operations workforce. A similar situation has occurred at the Mt Newman Iron Ore Mine in Western Australia where pyrite nodules which are widespread in black shale interburden, oxidize rapidly upon exposure;Corrosion, leading to failure of metal rock bolts, resulting in slope or roof collapse. In an underground nickel mine at Kambalda, Western Australia, oxidation of pyrrhotite in a warm, humid environment, caused corrosive failure of rock bolts within two months of installation;Physical disintegration of rock due to crystallization of sulphates in micro-cracks or inter-granular pores. This process has the potential to cause damage to structures such as retaining walls or rock-fill dams constructed of rock containing sulphides.
Formation of Cu–Au porphyry deposits: hydraulic quartz veins, magmatic processes and constraints from chlorine
Published in Australian Journal of Earth Sciences, 2023
G. N. Phillips, J. R. Vearncombe, J. D. Clemens, A. Day, A. F. M. Kisters, B. P. Von der Heyden
The process of solid, brittle, igneous rocks being hydraulically fractured by high fluid pressures to form mineralised veins has been widely recognised in studies of the formation of Archean greenstone gold deposits since the 1980s, e.g. Sigma mine in Canada (Robert & Brown, 1986), the Yandal Belt (Vearncombe, 1998), the Golden Mile and Mt Charlotte in the Kalgoorlie goldfield (Boulter et al., 1987; Ridley & Mengler, 2000; Travis et al., 1971) and the Hunt mine at Kambalda–St Ives (Phillips & Groves, 1984). These gold deposits comprise networks of auriferous veins and alteration that are hosted in Archean igneous rocks that have not been considered to be the sources of fluids or metals but, instead, are generally explained as rheologically favourable sites for fluid access. The ladder-vein networks of auriferous quartz veins in hydraulically fractured diorite at the Morning Star and A1 mines in the Victorian Gold Province have been mined and documented since the 19th century without any a priori assumption that the ore fluids and gold came from the host dykes (Anderson & King, 2017; McAndrew, 1965). Some of the broader structural principles discussed here are already being applied in the study of Cu–Au porphyry deposits (Corbett, 1994; Skarmeta, 2021) but, in other studies, these principles are not being used.
The Direct Leaching of Nickel Sulfide Flotation Concentrates – A Historic and State-of-the-Art Review Part I: Piloted Processes and Commercial Operations
Published in Mineral Processing and Extractive Metallurgy Review, 2023
Nebeal Faris, Mark I. Pownceby, Warren J. Bruckard, Miao Chen
The Sherritt-Gordon ammonia pressure leach process is employed at BHP Nickel West’s refinery in Kwinana, WA (formerly owned by WMC Resources) and was originally built to process nickel flotation concentrates from Kambalda. The plant was commissioned in 1970, however, with the commissioning of the Kalgoorlie nickel smelter in 1973, co-processing of matte and concentrate commenced, with the refinery switching to an all-matte feed in 1985 (Deng 1994; Wishaw 1993). Some advantages of switching to all matte feed were stated to be higher Ni tenors in the leach liquor, an increase in Ni throughput, reduced cooling requirements in the autoclaves due to the lower sulfur content of the matte feed, and generation of a smaller volume of leach residue (Deng 1993, 1994; Wishaw 1993). The operating conditions of the autoclave train at the Kwinana refinery processing flash furnace smelter matte grading 66 wt% Ni (ground to a P90 of 106 µm), are a temperature range of 85–95°C and a pressure of 750–1000 kPa using compressed air as the oxidant (Wishaw 1993; Woodward 2014; Woodward and Bahri 2007). The Ni-Cu-Corich ammoniacal solution is processed in a similar manner to the original Sherritt-Gordon process at Fort Saskatchewan which was previously described (refer to Figure 3). The primary difference is that further processing of the MSP product for recovery of cobalt values does not take place (Wishaw 1993). The refinery at Kwinana has undergone an expansion with the addition of a plant to produce 100,000 tonnes per annum of nickel sulfate (Anon, 2021) , a key ingredient in LIB cathodes used in electric vehicles.
Agile management and long-term strategy in exploration: the ‘lucky’ discovery of the Sinclair Pollucite Deposit, Eastern Goldfields, Western Australia
Published in Australian Journal of Earth Sciences, 2021
G. E. Batt, D. Crook, N. Brand, S. Kerr
Despite lying between the well-endowed mineral provinces of Kambalda and Norseman and sharing many details of their richly endowed Archean mafic and ultramafic stratigraphy (Figure 3), the Pioneer District saw little active prospecting until the Western Australian nickel and gold exploration booms during the latter part of the 20th century.