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By A G. Thompson, E Villaescusa, A De Zoysa, J R Player

Ground support performance is critical to the safe and economical extraction of ore. This is particularly important for mass mining extractions at great depth, which are currently being considered by a large number of mining companies worldwide. As the in situ stresses concentrate around critical excavations, failure occurs at the excavation boundaries and ground support is required for the excavations to remain safe and accessible for their intended lifespan. Ground support consists of reinforcing elements that are installed within the rock mass to modify its internal behaviour (generally to within one excavation radius) and surface support elements that are installed at the exposed boundaries to retain the failed pieces of rock. For surface support to be effective, the loadings need to be transferred to the reinforcing elements; however, the combined performance of rock bolts and mesh is poorly understood in terms of the energy dissipation capacity available for a typical ground support scheme implemented at most mass mining operations.Over the last 15 years or so, a large number of large-scale laboratory experiments have been completed at the Western Australian School of Mines (WASM) Dynamic Test Facility for reinforcement systems and surface support systems loaded separately. The objective of more recent testing has been to establish the combined energy dissipation capacity of typical and enhanced reinforcement systems combined with mesh surface support. Total energy dissipation has been separated into energy dissipation attributable to the reinforcement and to the mesh. The results of the tests are presented and compared with the existing WASM design demand and capacity guidelines.CITATION:Villaescusa, E, De Zoysa, A, Player, J R and Thompson, A G, 2016. Dynamic testing of combined rock bolt and mesh schemes, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 789–798 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

The expansion of hydrometallurgical operations, declining ore grades and upwardly spiralling production increases the demand for fresh and recycled water with low levels of contaminants. The minerals industry is also increasingly being forced both by regulatory and cost pressures to reduce the amount of liquid waste they produce. This requires a strong focus on waste reduction by recycling, regeneration and reuse. However, these measures are often not enough in arid countries for a forward progress and expansion of their mining activities.   It is often the case that in the arid and semi-arid countries the only available water is either sea water or underground (brackish to hypersaline) saline waters. Brackish waters can be desalted at a reasonable cost but the desalination of highly saline waters is challenging and expensive.   There are emerging reports that sea water and in some cases hypersaline underground waters are now used by various mining industries as process water. This study explores the possibility of the use of sea water in various mineral processing and hydrometallurgical processes and briefly discusses the benefits and problems related to the use of saline waters at the mine and mill site. Several cases studies and preliminary laboratory test results are presented.

Jun 1, 2010

By Rayner B

Five wells have been drilled in the Basker/Manta Block of VIC/P19, Gippsland Basin, resulting in sub-economic Intra-Latrobe Group oil and gas discoveries at Basker-1 and Manta-1. A total of 21 individual hydrocarbon bearing sandstones were intersected by the two wells. These reservoir sand bodies were deposited by fluvial processes in a lower coastal plain environment. The modelling of sand body orientation and geometry is a critical component in the evaluation of the two accumulations. Seismic resolution of the thin (average 2 m to 5 m) sand bodies is inadequate for mapping their orientation and distribution. Dipmeter data has been successfully applied to the problem of orienting the sand bodies using FMS images acquired during the drilling of Gummy-1 and reprocessed HDT data from Basker-1 and Manta-1. Prediction of lateral extensiveness (geometry) of individual sand bodies has also been attempted. Interpreted palaeocurrent direction from all three wells is dominantly from the NW to the SE. Reservoirs in the Manta-1/Gummy-1 area are interpreted to be predominantly channel sands, deposited by relatively low sinuosity streams. As such they would tend to have a laterally extensive, elongate geometry. Sand bodies deposited in the Basker-1 area show a predominance of laterally accreted cycles deposited by meandering streams. Channel geometry may then be limited in the downstream/upstream direction by internal permeability barriers such as clay plugs.

Jan 1, 1992

By G Ma, L Qi, J G. Shellnutt

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Emeishan large igneous province (ELIP) of SW China is host to magmatic Ni–Cu–(PGE) sulfide and Fe–Ti–V oxide deposits which contain economic to subeconomic concentrations of precious and base metals. The formation of a given deposit-type (ie sulfide versus oxide) is thought to be related to the type of parental magma (ie high-Ti versus low-Ti) and the subsequent processes (ie fractional crystallisation and sulfide segregation), which allowed for metal enrichment.We examined the PGE of Baima and Taihe oxide-bearing layered mafic intrusions from the ELIP (Shellnutt, Ma and Qi, in press), and compared them with the nearby Xinjie and Hongge intrusions as well as with the Emeishan flood basalts. The PGE results for the two intrusions are contrasting. The Baima gabbroic rocks are almost PGE-barren (SPGE < 4 ppb) whereas the Taihe gabbroic rocks are variable, but generally much higher in PGE concentrations (SPGE < 2 to ~300 ppb), although the gabbros from both intrusions are enriched in platinum-subgroup PGE (PPGE = Rh, Pt and Pd) relative to iridium-subgroup PGE (IPGE = Os, Ir and Ru). Cu/Zr, Ni/Ir, Y/Pt, Cu/Pd and Ni/Ir systematics suggest that the Baima rocks were derived from a relatively evolved, mafic, S-undersaturated parental magma that was affected by earlier sulfide segregation. In contrast, the Taihe rocks record evidence of both S-saturated and S-undersaturated conditions and that the parental magma was likely emplaced very close to S-saturation. Through comparison of the PGE contents in the Emeishan flood basalts and the Emeishan oxide-bearing intrusions, we provide a self-consistent model for ELIP that the PGE budget in a magma is not strictly controlled by magma series (high-Ti versus low-Ti), but very much by crustal contamination.CITATION:Ma, G, Shellnutt, J G and Qi, L, 2015. Platinum group elements in the Baima and Taihe Fe-Ti oxide-bearing gabbroic intrusions of emeishan large igneous province and problems on propensity of magma series for sulfide- versus oxide-dominated deposit types, in Proceedings PACRIM 2015 Congress, pp 303–310 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By W J. Rankin

Metals are well suited to sustainable development goals. They are not biodegradable and have virtually an unlimited lifespan and the potential for unlimited recyclability. Thus metals can be considered as renewable materials. However mineral resources, the source of primary metals, are ænon-renewableÆ as their supply is finite, but this does not necessarily mean scarcity. In this paper the results from a series of Life Cycle Assessments of primary metal production processes for copper, nickel, lead, zinc, aluminium and steel have been used to examine how metals may contribute to societyÆs transition to sustainable development. Particular issues considered include:current metal reserves and how these may change in the future; some of the environmental impacts (Total Energy, Global Warming Potential and Acidification Potential) associated with primary metal production and how they will be exacerbated by declining ore grades; new processing technologies with lower energy consumptions and improved metal extraction efficiencies that will reduce reserve depletion and environmental impacts; increasing the utilisation of æmetals in useÆ by recycling, with particular reference to aluminium; and the potential impact of a carbon tax on metal prices and how this may influence the ways in which metals are used in the future.

Jan 1, 2002

The published liquidus data on the Pb-PbS system have been correlated on the basis of one-coefficient Margules equations. Thermodynamic properties of the components of this system have been obtained, and it has also been found that the calculated miscibility gap of this system exists over a very narrow range of temperature (1041 to 1058°C).

Jan 1, 1972

By C S. Szentesy, K Howie

The Rosia Montana gold deposit is located within the æGolden QuadrilateralÆ area in the Apuseni Mountains of Transylvania, Romania. The deposit is situated approximately 85 kilometres north of the regional centre of Deva, within the province of Alba, at elevations of up to 1100 metres above sea level. The Rosia Montana deposit contains a current resource of 344.07 million tonnes at an average grade of 1.3 grams per tonne (g/t) gold (Au) and 6.0 g/t silver (Ag) for a total (measured, indicated and inferred) contained resource of 14.29 million ounces of gold and 67.00 million ounces of silver. The resource was calculated using a 0.6g/t Au cut-off, a 10 x 10 x 10 metre block size and multiple indicator kriging. The low sulfidation style epithermal mineralisation at Rosia Montana is hosted within Tertiary age dacite intrusions and related vent breccias. Mineralisation is generally disseminated and associated with silica, adularia, illite, pyrite and carbonate alteration of host rocks, with minor late carbonate-base metal veins. Precipitation of precious metals is generally considered to have occurred as a result of over-pressurization, boiling and subsequent brecciation. The dacite intrusions are hosted in Cretaceous shallow marine and deltaic shales and slates, which overlie older Paleozoic sedimentary and metamorphic rocks within uplifted sections of oceanic sea floor.

Jan 1, 2002

THE Broken Hill mining field, approximately 31 miles in length, is at present being exploited by seven companies, viz. : North Broken Hill Limited, Junction North Broken Hill No Liability, Broken Hill Proprietary Block 14 Company, Broken Hill ProprietaryCompany Limited, Sulphide Corporation Limited, Broken Hill South Limited, and Zinc Corporation Limited.The variation in size and shape of the ore-bodies in the mines of these companies, together with the many alterations in pitch and dip, necessitates differences in methods of mining, each company working out its problem in its own particular way.In the matter of chute construction for the handling of the ore broken in the stopes, each mine belonging to the above companies has adopted a style particularly its own, though it may be said that one or two of the types approximate very closely to each other, slight minor differences only being noticed in the design. It is the purpose of this paper to give a brief description of the principal types of chutes now in use in th,e various mines on the field, and in doing so they may roughly be classified into three groups, viz:1. Bulk Chutes, 2. Circular Chutes, 3. Square-set Chutes.The Bulk type of chute is used in the North and British mines of the North Broken Hill Limited, the Central and Junction mines of the Sulphide Corporation, the South Blocks mine of the Zinc Corporation, and the Block 14 mine.The Circular type of chute is used by the Broken Hill South mine and the South Blocks mine.The Square-set chute is used in the Proprietary mine, the Junction North mine, and occasionally in other mines where the square set method of mining is a necessity, and more particularly as mullock passes.

Jan 1, 1925

By Zwaan J, Kepa J

Ok Tedi mine has become one of the major copper producers in the world. In the process of becoming of age, it overcame the challenges of operating in a locality which is young in geological terms, experiences very high rainfall and has a topography which gives rise to frequent landslides. This paper discusses some of the geological, mine and geotechnical engin- eering aspects of the Mt Fubilan ore deposit.

Jan 1, 1991

Flat jack stress determinations in selected colliery roadways have revealed a range of measured stress from 330 lb/sq. in. tension to 3,750 lb/sq. in. compression. Photoelastic examination of loaded plastic and actual rock model mine openings has shown that the primary horizontal stress required to attain these measured stresses would be from one to three times the superincumbent vertical load.Examination of roof movement with a borehole extensometer and a series of anchors at various horizons to 30 feet in a vertical roof borehole showed that when a standing face was advanced the roof movement was practically confined to the lower two feet. The majority of this movement occurred during the 36 hours after mining at this face commenced.The use of a radioactive isotope and a scintillation counter in a pair of parallel boreholes is a sensitive and accurate method of roof bedding plane crack detection.INTRODUCTIONA knowledge of strata stresses is required to understand the deformation of an underground opening and, in particular, the roof behaviour. It is the aim of investigations currently being conducted by Australian Coal Association (Research) Ltd. to determine the stress existing around mine openings and the location and magnitude of roof movement.STRATA PRESSURE MEASUREMENTMost measurements of strata stress are performed at the surface of underground openings and the majority measure the change of strain resulting from stress relief. The accuracy of the measured value of stress depends upon knowledge of the rock modulus of elasticity. The flat jack method has the advantage that strain relief is restored by a measured stress applied directly by the jack. The rock modulus of elasticity can also be determined.

Jan 1, 1963

The Burra Burra Mine is situated in complexly folded Torrensian dolomites and limestones forming the faulted axial region of a major anticline. The orebody mined was largely of secondary origin and confined between two faults, Kingston's on the west and Tinline's on the east. The orebody occurred at the junction between cherty dolomites and a clastic limestone with a large mass of marble breccia along its western margin. Secondary ore consisted of carbonates and oxides in the breccia and the ore bed and detrital copper minerals deposited as part of a clastic breccia in sinkholes and solution cavities in the dolomites and ore beds.Primary sulphides occur disseminated in the marble breccia and in stratiform habit in the ore bed. Kingston's so-called "lode" may be mineralized marble breccia.The marble breccia appears to be of diapiric or sedimentary origin and there is evidence to support a sedimentary origin for some of the copper sulphides. No igneous rocks have been discovered within 20 miles of the mine and any hydrothermal activities were probably at comparatively low temperature. The possibility of extensive stratiform and disseminated copper sulphide mineralization in the marble breccia and ore bed requires testing by further drilling and geophysical surveys.INTRODUCTIONThe re-interpretation of Burra Burra geology and ore formation discussed in this paper resulted from a comprehensive investigation of the mine and its surrounding district begun in December 1961 and in progress at the time of writing. (February 1963). The decision to investigate Burra Burra was taken after a thorough examination of records and reports of all non-ferrous metal deposits throughout South Australia and was given impetus by a report by Thomson (1963) suggesting a sedimentary origin for the copper mineralization. Although the author does not concur fully with Thomson's interpretation there is no doubt that sedimentary processes have played an important part in the formation of the Burra Burra copper deposit, nor is there any doubt that igneous activity played no part.

Jan 1, 1963

Frother-Depressant Interactions in Two and Three Phase Systems

Sep 13, 2010

The mineralogy and textures of a portion oC ore from the 25 level northern orebody, North mine, Broken Hill are described. This ore, in places, contains up to 70 per cent cubanite (CuFe2S3 ) which has crystallized directly with other sulphides and associated gangue minerals.Several breakdown reactions involving the cubanite are also considered.

Jan 1, 1969

By M Bourke

Modern computers and software provide powerful tools for the geologist to construct reliable models of geological resources, and the mining engineer to produce accurate and workable mine plans. Over the years many people have developed a phobia of computers, especially for geological analysis, modelling and mine planning. This phobia is often caused by a lack of knowledge, poor training or a bad experience. The adoption however of computers for geological modelling and mine planning is now becoming mainstream. With the correct training, a good understanding of input data, and detailed knowledge of the required results, the phobia can safely be overcome to provide mining operations with increased productivity.

Jan 1, 1999

Despite a long history of production of industrial minerals and rocks, New South Wales still offers significant opportunities for exploration for and development of these minerals. Exploration for opal, sapphires, and zeolites in the State has been particularly encouraged by pioneering geological studies by the Department of Minerals and Energy, which have resulted in the development of important new geological concepts and exploration techniques. Large areas with potential for these minerals have not yet been tested. In the case of sapphires, the studies have identified a new type of deposit which is'the source of most of the sapphires mined from alluvial deposits. Recent price increases for heavy minerals, a re-evaluation of previous exploration in coastal regions, and a recognition of suitable environments in inland New South Wales have stimulated renewed exploration both onshore and offshore and have led to increased production. Significant potential also exists for development of a number of other minerals, including: topaz, which occurs in large, unusual and perhaps unique deposits in northern New South Wales; dimension stone (particularly granite); bentonite; diatomite; and silica for metallurgical use. Potential also exists for development of construction material resources, particularly construction sand, which is in short supply in the Sydney region.

Jan 1, 1989

The sedimentary basins of this region developed in the collision zone of thePacific Ocean plate and the continent. Stresses were transmitted thorough wedge-like lithospheric blocks, such as the Okotsk Sea, East Kamchatka, Aleutian and other smaller blocks. Compression and inversion were more active at the boundaries: ***INSERT EQ*** and ***INSERT EQ*** in places. Tension, rifting and the increase in the rate of sedimentation were marked in P1-2, P3, N12, and also in N2 û Q in places. Structural plan changes of the sedimentary basins and possible oil, gas and fluid migration occurred more actively at the boundaries: ***INSERT EQ***.

Jan 1, 1995

By G J. Lyman, S A. Tittlemier

International regulations exist to manage the concentrations of mycotoxins such as Ochratoxin A (OTA) and deoxynivalenol (DON) in grains and prevent health risks from excessive exposure to OTA and DON. Since the permitted levels of these mycotoxins are very low (existing maximum levels are in the range of 5 ppb for OTA and 1–2 ppm for DON), sampling for these mycotoxins is potentially challenging. Given that the distribution of infected kernels in a consignment of wheat can be highly heterogeneous, detection by current sampling methods is subject to a high variance. Furthermore, the concentrations of mycotoxins in individual kernels vary over orders of magnitude, intensifying the heterogeneity of the bulk grain.In these circumstances, there is much interest in developing sampling plans that inform regulatory agencies, and mitigate the risk of misclassifying grain shipments as compliant or non-compliant within the global grain trade, when correctly implemented.Experimental data from laboratory and field studies describing individual wheat kernel concentrations of OTA and DON were combined with experimental data describing the variance due to the analytical methods used for OTA and DON to calculate the sampling distribution for wheat having various levels of contamination. This work has focused on quantifying the heterogeneity of samples at the point of submission for analysis and within subsequent sample preparation to arrive at total sampling distributions that include uncertainties due to the intrinsic heterogeneity and the analytical uncertainties. The sampling uncertainty that relates to the difference between the primary sample analysis and the true lot analysis is not included as it has been dealt with elsewhere.CITATION:Lyman, G J and Tittlemier, S A, 2017. The sampling characteristics of grains contaminated by mycotoxins, in Proceedings Eighth World Conference on Sampling and Blending , pp 281–294 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

Adhesion of Escherichia coli onto Oxide Minerals - Extended DLVO Theory and Flotation Behaviour

Sep 13, 2010

Stope back conditions in the cut-and-fill stopes at New Broken Hill Consolidated Limited often deteriorate to such an extent that, because conventional rockbolts are not able to maintain safe working conditions, square-set timber is installed. An attempt to eliminate this costly procedure has involved the use of long grouted rockbolts using high tensile prestressing wire. These bolts were developed in conjunction with the prestressing engineers of BBR (Aust.). This form of support has improved the back conditions, maintained safe working conditions, and delayed the introduction of timber in a number of stopes.Production from these stopes has been maintained at its previous level (at a rate approximately double that of a comparable timber stope).

Jan 1, 1974

The Martha deposit is an economic giant epithermal gold deposit, with mined and unmined resources of more than 218 000 kg (7 Moz) Au. The Au-Ag, base metal sulphide-bearing quartz lodes in the Martha deposit form an extensive braided pattern within hydrothermally altered andesite wall rock. There are five main quartz lodes: 1.      Martha, 2.      Welcome, 3.      Edward, 4.      Empire, and 5.      Royal.   Information from historic mine plans and reports has been used to determine the depth distribution of economic ore within the Martha deposit. Economic ore (average of 10 g/t Au) in the Martha underground mine was at a maximum width and strike length between a vertical depth of 160 and 350 m. Below this depth the quartz-sulphide lodes continue, but the grade declined to sub-economic grades (< 4g/t Au) at about 575 m depth and economic ore shoots were localised, mainly on the hangingwall side of the lodes. Samples from exploration drill holes indicate that this decrease is associated with a depth zonation from electrum-bearing Zn-Pb-Cu-Ag sulphide ore (average 10 g/t Au) to sub-economic (< 2 g/t Au) electrum-poor Zn-Pb sulphide mineralisation.

Jan 1, 2006