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Results of investigations on adsorption and desorption of CO M CH and a mixture of the two gases are described.4 Results showed that even when the equilibrium conditions contains 50% Co and 50% CH4, the gas emission in the initia' stages will contain as much as 80% CH . 4 The temperature has a small effect and so also particle size for 1.4-11.2mm. The ratio of CO2/CH gases adsorbed in coal samples depends upon t4he equilibrium pressure and this ratio decreases with pressure. Results of field tests support laboratory studies.

Jan 1, 1988

By Doyle P, Mulroney D

The Cassidy Shaft was sunk to access the Mount Charlotte and Reward Orebodies below the Flanagan Fault. The 1,184m deep shaft is concrete lined to 6.5m diameter for its full depth. The initial 590m was excavated by stripping into a 1.8m diameter borehole and hoisting the broken material through the existing mine. The remaining 594m was excavated by conventional shaft sinking methods. The shaft was sunk through 3 existing plats and an additional 8 plats cut. 1,800 tonnes of steel and 8 cables were installed during the furnishing of the 4 compartments.

Jan 1, 1985

Geological information plays a significant, cost effective role, in the Mt Whaleback iron ore mining operations. The geology and structure are complex. Good communication between the Mine Planning Production Scheduling and Quality Control Sections is the key to utilisation of geological information to its full potential.Drilling and pit face mapping are the two basic sources of detailed data sets which are processed to prepare up to date geological cross sections and benchwise geological plans. This information is used directly for the blast pattern design and production scheduling. Physical ore type estimation is also undertaken. Orebody models are generated from the geological information.

Jan 1, 1990

By Fabjanczyk M. W

The design of underground mine roadways (tunnels) requires a detailed understanding of the in situ stressfield, the rock failure modes, the performance characteristics of reinforcement or support members and assessment of the stress state about the roadway. Definition of these factors, together with monitoring of roadway behaviour during both development and extraction operations, allows rational design procedures to be undertaken.The design approach utilised computational techniques to simulate the behaviour of the strata about the opening for a range of anticipated stressfields and various reinforcement options. Field validation studies are conducted to confirm the design expectations.

Jan 1, 1993

With the sinking of the No. 3 Shaft at North Broken Hill Limited, it was necessary to construct adjacent to the shaft a new changehouse for mining and surface personnel.It was also probable that as the older sections of the North and British leases were worked out, all employees at present working in these sections would be transferred to the No. 3 Shaft area. This could ultimately result in all personnel employed by North Broken Hill Limited being concentrated in this area, requiring the construction of new administration offices, workshops, mine store, etc., also in this area.

Jan 1, 1957

By Ooms M, Scott OJ

This paper is concerned with the design and operation of storage and discharge facilit- ies for bulk solids handling. It presents an overview of the basic design philisophy emphas- ising the influence of bulk solid flow propert- ies and bin geometry on the flow patterns developed and how these, in turn, affect the reclaim efficiency and the bin structural in- tegrity and wear characteristics of both bins and chutes. The salient aspects of feeder design and operation will be discussed and the need to consider feeders as integral parts of the bin discharge system will be stressed.

Jan 1, 1978

The Abra mineralized body is regarded as a significant new style of mineralization for its environment. It is a blind polymetallic deposit, located in the Bangemall Basin of Western Australia. It was discovered by Geopeko in 1981 by diamond drilling a coincident magnetic gravity target, which revealed a large low grade epithermal Fe-Ba-Pb-Ag-Cu-(AuW) deposit, hosted by chemogenic and clastic sedimentary rocks, overlain by 200-500 m of clastic sedimentary rocks, of Middle Proterozoic age. The mineralization occurs as an upper stratabound phase, and a lower vein "stringer" style phase within a pervasive chlorite alteration envelope.

Jan 1, 1987

The Pacific Rim countries ofAustralia, New Zealand, Papua New Guinea, Indonesia, Fiji, Philippines and Solomon Islands will be reviewed from an equity investors perspective.   The following areas will be covered: Country risks Exploration spending and activity Project development Taxation Relative cost of doing business Environmental considerations Political/bureaucratic situations Capital raising Equity markets as a source of funds Developing market funds The aim of the paper will be to outline the most attractive areas for investment by equity and private funds plus documenting the changes needed in the less favourable countries if they are to attract investors.

Jan 1, 1995

By D Reid

Run-out analyses of tailings storage facilities are typically undertaken using methods based on rheological theory. These are reasonable techniques to model the behaviour of tailings that, through significant run-out and possibly mixing with supernatant water, are generally acting in a fluidised manner. Such modelling often follows on from two-dimensional continuum analysis models where, if failure is predicted, grid failure often occurs when deformations begin to increase. This results in a disconnect between the prediction of failure and the modelling of the potential extent of the failure.Recently, rezoning methods have been incorporated into commercially available two-dimensional soil mechanics deformation codes. Rezoning techniques enable large deformations to be modelled within a two-dimensional continuum analysis framework; however, while promising, the use of such tools is not yet widespread, and a consensus is yet to develop on how they should be applied to tailings dam run-out modelling.This paper uses FLAC rezoning techniques to model the flow behaviour of two historic tailings dam failures. The purpose of these analyses is to critically assess the performance of rezoning against some available historic failures. The required data to undertake such an analysis is outlined, along with the inherent limitations and assumptions required. Parametric analyses are outlined to address some of these issues. In general, the analyses undertaken underestimated the flow distance observed in the historic failures by varying degrees; however, in some instances, the analysis reasonably reproduced the qualitative shape of the initial failure zone. A variety of potential reasons for the discrepancy between historical observations and the models undertaken are provided.CITATION:Reid, D, 2015. The use of rezoning techniques to model historic tailings failures, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 201–206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By P Stewart, S Cowie, A Offer, J Carpenter, E Jones

The Ban Houayxai Gold-Silver Operation is a producing asset for Australian-based copper and gold producer, PanAust Limited. The Operation lies within PanAust’s 2600 square-kilometre Phu Bia Contract Area in northern Laos. Commencing production in 2012, Ban Houayxai is operated by PanAust’s Lao-registered company, Phu Bia Mining. PanAust owns a 90 per cent interest in Phu Bia Mining. The Government of Laos owns the remaining 10 per cent. The Operation mines an intermediate sulphidation epithermal gold-silver deposit and comprises an open-pit feeding ore to a conventional carbon-in-leach process plant. Metallurgical recoveries for gold and silver are approximately 75-85 per cent and 55 per cent respectively. To year-end 2017, the Operation had poured 0.65 million ounces (oz) of gold and 4.7 million oz of silver. The Ban Houayxai Ore Reserve supports a mine life of approximately four years from the end of 2017. The Ban Houayxai deposit is in an early Permian volcano-sedimentary unit which is part of a late Carboniferous to early Permian (310–270 million years ago) volcanic-plutonic sequence of the Truong Son Fold Belt. The deposit formed when hot saline (240–415°C, 2.7–13.0 weight per cent NaCl equivalent) fluids ascended from a geologically fertile island arc porphyry into overlying volcanics along a fault or faults in the early Permian (290–256 million years ago) (Manaka et al, 2014). CITATION: Carpenter, J, Cowie, S, Stewart, P, Jones E, and Offer, A, 2018. Machine learning at a gold-silver mine: a case study from the Ban Houayxai Gold-Silver Operation, in Proceedings Complex Orebodies Conference 2018, pp 82–85 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

Over the past five years, dedicated tertiary mining engineering programs have become financially unsustainable in Australia on the basis of undergraduate enrolments alone. The situation is worse in other minerals related disciplines and extends to the technical minerals education sector. This paper reviews the causes for the current situation. Indicators are presented which suggest that enrolment trends can no longer be attributed only to business cycles in the minerals industry but are also reflective of a fundamental shift in student interest in the sciences and resources based engineering disciplines. Reactive responses to changing trends are diluting and compromising the quality of mining engineering education. It is unlikely that the trends can be reversed or resisted. Tertiary minerals educators need to position themselves so that they can be responsive to on-going change. Two proposals are offered which aim to anchor mining engineering in a long-term sustainable manner. The proposals have a common educational component which is concerned with restructuring how mining engineering programs are presented and providing more flexible access to such programs. However, the two proposals have significantly different commercial components. The commercial component of first proposal is concerned with working within the traditional education framework of universities to endow a critical number of core staff positions. It effectively equates to fund raising. The second proposal is concerned with developing a stand-alone commercial operation around the education and research advantages of the global and multi-disciplinary university system. As a shareholder in this business, a university department would earn dividends that it could then use to support its education initiatives. This proposal provides a performance-based mechanism for supporting university minerals programs and has the potential to be cost-neutral. Both proposals are suited to resource sharing with a select number of international mining schools and to the incorporation of the other tertiary minerals disciplines under threat.

Jan 1, 2000

The recent description provided by Scott (1981) of the Ardlethan alteration systems is of particular interest as it draws attention to the analogy between Ardlethan and the porphyry tin systems of Bolivia (Sillitoe et aI, 1975).During 1978-1979 a parallel study of the mineralization confirmed that the extensive alteration pattern relates to a series of breccia pipes which provide access channelways for the mineralizing solutions (Clarke, 1979). Many of the results reported by Scott are difficult to interpret without this concept and this short discussion is intended to provide additional perspective to the proposed porphyry tin model.The breccia pipe systems are centred upon each of the major mineralized zones (Wild Cherry, Carpathia, Stackpool and White Crystal) and with the exception of the White Crystal collapse breccia the major pipes are of the hydrothermal intrusive type. They range considerably in size and shape and at least two ages of formation are revealed by their cross cutting relationships at the Stackpool, Carpathia and Ardwest regions. Individual pipes or groups of pipes have distinctive alteration/infill characteristics and the entire system can be viewed as a complex porphyry tin system evolving with time. The recognition of pipes of different types and ages reveals a situation considerably more complex than suspected by Scott, and hence both the geochemical data and modelling require reinterpretation.For instance, the geochemical data contained within Tables 2 and 3 (Scott, 1981) relate to two separate breccia pipes which correspond to the South Cherry and Ardwest ore zones respectively. Although it is probable that both pipes are temporarily identical it is important that the geochemical data be viewed in context. The brecciation is extremely difficult to recognize and it is probable that the chemical compositions given represent mixtures of altered fragments and rock flour, together with material precipitated from solution as matrix, along microfractures, within small vughs, etc.

Jan 1, 1982

By I Warren, M P. Simpson

Adularia-sericite epithermal ore deposits have well-documented alteration mineral zonation patterns with distinctive geochemical signatures. Proper use of whole-rock geochemistry can provide useful vectors for exploration and can enhance efforts to characterise and quantify the mineralogy and intensity of hydrothermal alteration.   Analyses of Au and Ag provide the most direct vectors to orebodies, and pathfinder elements such as As, Sb, Hg, Zn, Pb and Se are similarly zoned around at least some orebodies. However, the minerals that contain these elements occur almost exclusively in veins, and therefore identifying geochemical vectors related to wallrock alteration that is zoned outward from orebodies is crucial for effective exploration.   Distal alteration zones contain quartz-illite-chlorite-carbonate-pyrite, whereas samples proximal to veins contain quartz-adularia-pyrite, with lesser though variable illite-chlorite-carbonate. Therefore, adularia-sericite epithermal ore deposits show K alteration in their cores. The resulting K-metasomatism can be evaluated in several ways. Areas that have been most intensely altered are commonly characterised by highest K contents, but these results can be complicated by variations in rock type across the prospective area. Potassium mass balance results provide a robust and rigorous assessment of K-metasomatism, however, knowledge about the composition of fresh rocks and correct identification of fresh precursor compositions of altered rocks are required. Three alteration indices provide effective evaluation of K-metasomatism: 1.   the K number, which is the ratio K/(2Ca+K+Na) (molar); 2.   Barrie values [(K2O * 100) / Sr]; and 3.   the Rb/Sr ratio. In most places these provide similar vectors, although K numbers can be complicated by the appearance of hydrothermal calcite and/or albite.   Plots of K/Al vs (2 Ca + K + Na)/Al (molar) allow estimation of the intensity of K-metasomatism and its mineralogical products, thereby complementing traditional XRD and petrographic studies of alteration minerals.

Jan 1, 2005

Although the effects of sea level changes on ore concentration processes are to some extent obvious with certain deposits, e.g. beach placer deposits, they have been largely overlooked with others such as Mississippi Valley type lead-zinc deposits. It is contended that sea level variations may have more profound effects on a wide range of deposits than has previously been appreciated. These deposits include not only placer'and residual deposits but also stratiform copper deposits, Mississippi Valley type deposits, stratiform manganese deposits and Minette type iron deposits. Sea levels in paralic basins profoundly affect the influx of 'detrital sediment, and this has to be suppressed to allow for the accumulation of thick rich deposits of coal evaporites, phosphate or metalliferous sediment. Emergence can be associated with oxidized waters, erosion, and,solution of soluble rocks. Submergence can reverse the Eh trend and can lead to preservation of ores. Both realms of surficial sedimentary environments and subsurface diagenetic environments can be affected by changes in water pressure, gas pressure (pC02), Eh, pH, and temperature as sea levels fluctuate. Even relatively small sea level changes may have profound effects. For example, there is some evidence to suggest that when the level dropped below 100 metres about 10,000 years ago, the Red Sea became isolated by the sill at Bab el Mandeb in the south, and evaporated away to leave a series of shallow lakes. The Red Sea is 1 to 2 km deep. It was at times such as this that the well-known copper-zinc mineralization developed in the Red Sea trough. Changes in sea level also affect the stability field of gas hydrates which can yield large volumes of gas leading to mass movements on the sea floor (Warnke, 1986).

Jan 1, 1987

The reduction of titanium tetrachloride to trichloride can be achieved by employing hydrogen and electric arcs. It is possible to produce melts containing up to 50% TiCk in the eutectic mixture of LiCl/KCl by striking a D.C. arc at the surface in the presence of hydrogen and TiCl. vapour. If the electrode IS made to just penetrate the surface of the salt mixture, a hot zone results from the' high resistance contact with both lower chlorides and sintered titanium may be produced. The sintered metal forms just below the melt surface while the trichloride forms at the gaslIiquid junction.The "hotspot cathode" appears to offer a solution to the problem of producing coherent deposits as the spong'e metal can 'be continuously withdrawn in a similar manner to the "calcium process".INTRODUCTIONConsiderable interest has been shown for some years in the possible development of a cheap electrolytic process for the extraction of titanium metal, since a method using simple materials and cheap electric power would materially reduce the cost of production. Even when cheap starting materials are used, however, there exist several general difficulties in the operation of plant which both limit the speed of production and increase the cost of the product. It happens that most of the techniques so far tried produce a powder as cathodic deposit, and when this is the case the following difficulties arise:1. The whole contents of the bath must be treated with solvent in order to extract the 'metal powder which may itself tend to oxidise, and thus become contaminated.2. Fine metal powders, which often contain residual entrained salts, are less easy to consolidate by arcmelting than metal sponge.

Jan 1, 1956

By P Cepuritis, G Chitombo a, I Brunton

There is a significant amount of past evidence that links blasting and occurrences of slope failure. Particularly of great concern at Telfer Gold Mine is the effect of open pit blasting on the stability of the footwall slope above the underground portal and the stability of underground structures. For this reason, Newcrest Mining Ltd invited JKMRC to conduct necessary field measurements and numerical modelling with the following objectives:assess the dynamic stability of the footwall slope above the portal; assess the characteristics of current and future blasts in the open pit; and prepare open pit blasting guidelines that will minimise the detrimental effect of blasting on slope stability. To achieve these tasks it was necessary to develop a scaled distance attenuation curve for blast vibrations. In order to validate the developed vibration attenuation curves it was necessary to monitor vibrations from a production blast. Using JKMRC blast design software tools, the vibration of the production blast was also modelled from the blast design and vibration results from single hole blasts. The intention was, assuming that the observed and modelled vibrations were close in terms of frequency and amplitude, to use the software tools to model the vibrations of future blasts and assess their likely effect on slope stability. Numerical modelling of the dynamic stability of the footwall slope was done using the FLAC finite difference code and the UDEC distinct element code. The results of the numerical modelling and of the field measurements of the blast induced ground vibrations were combined into the blast design rules that relate distance between the slope and the blast, charge weight per delay and number of blasts necessary to cause failure of the slope.

Jan 1, 1999

By B G. Lottermoser

The placement of sulfidic waste below the groundwater table ensures limited interaction with the hydrosphere and suppression of sulfide oxidation. However, if sulfidic waste is placed above the groundwater table and remains uncovered, the backfill becomes part of the unsaturated zone and is exposed to atmospheric oxygen and leaching. This study aims to establish the leaching behaviour of sulfidic waste placed above the groundwater table and the impact of such leachate on the local aquifer at the Thalanga base metal mine. Mining of the Thalanga copper-lead-zinc deposit resulted in a large final mining void (600 m + 150 m + 70 m) and extensive underground workings. The underground workings were partly filled with tailings and the open pit was partly backfilled with acid producing sulfidic waste rock. In addition, the pit serves as a sink for acidic run-off from adjacent waste rock piles and mine workings. To date, the backfill of sulfidic waste rock placed into the pit has not been capped with benign materials and for most of the dry season, the surface of the backfill is covered by melanterite-type efflorescences. Results of kinetic column leach experiments conducted on the sulfidic waste indicate that Cd, Cu, Zn and SO4 rich waters migrate from the backfilled sulfidic waste into the local unconfined aquifer. However, the seepage of alkaline (pH 7.3 - 8.0), high conductivity (>10 000 ¦S/cm) tailings waters into the remaining pit void clearly shows that the acid leachate originating from the sulfidic waste rock does not impact beyond the waste repository and its immediate environment. Geochemical modelling implies that minimal or no mixing occurs between the acid waste rock leachate and the alkaline tailings waters.

Jan 1, 2003

By McIlveen GR

The water pollution hazard posed by the derelict Conrad mine site, to the water and associated stream sediment of Borah and Maids Creeks and the nearby Copeton Dam storage, has been assessed. Mine water, tailings and tailings dump leachate have polluted water and stream sediments in Borah Creek downstream of the mine site. Acidity, arsenic, copper, lead, iron, silver and zinc are the principal pollutants. Under dry and low flow conditions, mine water was found to be the dominant polluting source, however, leachate and run-off from tailings dumps were also significant under and following wet conditions. Soluble arsenic, lead, iron and silver species in mine water and leachate were found to be rapidly incorporated into sediments, but acidity, copper, and zinc persisted in the creek water. Under low flow conditions, the water of Maids Creek is polluted with copper and zinc (up to 4.4 and 34 mg/l for copper and zinc respectively) and the pH is decreased (from pH 5 - 7 to pH 3 - 6) by entry of Borah Creek water. Values found in Maids Creek were variable and related to flow regime and distance downstream from Borah Creek confluence. Water in Copeton Dam storage, having a much larger volume of water with a higher bicarbonate buffering capacity (50mg/l versus 15mg/1), is not affected by entry of Maids Creek water. Polluted sediment from Borah Creek has contaminated Maids Creek for 2km downstream to Copeton Dam storage. Stream sediment downstream of the Borah Creek confluence, contains up to 1.0% As and 1.4% Pb in the less than 200 micron size fraction. Under high flow conditions, arsenic was found to be moved out from the mine site as insoluble species, associated with suspended sediment in Run-off.

Jan 1, 1988

By K Hskansson

In earlier studies along a mining region recipient (the river VormbScken, northern Sweden), the fraction of certain trace metals recovered in the particulate phase has been found to increase with increasing concentrations of particulate iron. This study was conducted to see if the pattern could be reproduced by adding minor amounts of ferrous iron, simulating groundwater inputs. When the iron is oxidised in the near neutral river water, it will form iron oxyhydroxides and precipitate. Trace metals may be either co-precipitated along with the iron, or adsorbed onto the freshly formed precipitates. If this is the case, such a mechanism may be incorporated as a part of a final polishing step in a mine drainage treatment system based on natural attenuation processes. The experiments were performed at 0¦C and 22¦C, on authentic river waters collected during the winter and summer of 2002, respectively. In order to investigate the influence of particles and bacteria initially present, filtered river waters (4 solution were added to the experimental beakers, increasing the iron content of the waters by 0 - 1.5 mg/L. The oxidation and precipitation processes were followed by means of filtration (0.2 ¦m) for up to seven days. In order to be able to compare the experimental results with the actual field situation, on both experimental occasions, surface water samples were collected also from three stations situated along the river. The samples collected were analysed for iron, calcium, and trace metals by AAS and ICP-MS. The iron oxyhydroxides formed in the experiment did not influence the partitioning of As, Cu, and Pb to the same extent as the particulate iron encountered along the river appeared to do. Cd and Zn were recovered mainly in the dissolved (

Jan 1, 2003

The paper gives details of the performance of a 6-ft. by 6-ft. grate discharge ball mill which was converted into a rod mill of the overflow type and then into a grate discharge rod mill. Proposals for further alterations are outlined.INTRODUCTIONThe mill of King Island Scheelite (1947) Limited recovers scheelite by gravity methods.Crushed ore at the rate of 34 tons per hour is divided between two mills. (6 ft. by 6 ft. and 8 ft. by 6 ft. respectively), the mill discharges being pumped to a common distributor which feeds seven Hummer Screens. Each screen has three 4-ft. by 2-ft. Ton-cap sections and repulping compartments are provided. The screen oversize is returned to the mills whilst the screen undersize is finished grinding section product. A third (6 ft. by 6 ft.) mill regrinding the coarser table tailings also discharges into the common Hummer Screen Distributor.The screen undersize is pumped to a bowl classifier which separates at 200 mesh. The bowl classifier sands are treated on tables whilst the bowl classifier overflow, after thickening, is treated in the slime plant by flotation. The flotation concentrate is further concentrated on vanners and slime tables.A recovery of 80 per cent. is possible by tabling whereas only 50 per cent can be recovered in the slime section. The object of comminution is, therefore, to reduce all the new feed to less than a certain mesh (22 mesh Tyler) with the production of a minimum quantity of minus 200 mesh material. cheelite is, a very friable heavy mineral (Sp.Gr. 6'0) and is therefore susceptible to overgrinding. For the evaluation of grinding performance it is hence advisable...

Jan 1, 1955