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HoistEM is a helicopter-towed time domain electromagnetic system. This paper presents details of the towed array structure (the Hoist) as well as a description of the instrumentation. A comparison between HoistEM and ground TDEM (from which HoistEM was derived) is given. Over 50 000 line kilometres of HoistEM have been completed to date and datasets for structural mapping, nickel, base metals, manganese, ground water and bathymetry are presented and discussed.

Jan 1, 2004

Since 1969, a substantial number of geophysical methods have been applied in the search for porphyry copper and mesothermal type -sulpha-de deposits. These have assisted with geological mapping as well as the definition of various sulphide depos-its. The application of these methods at the Frieda-Nena deposits, Papua New Guinea, can be used as a case study for exploration in other parts of New Guinea.In 1993, Highlands Gold Limited carried out an intensive geophysical program over the Nena deposit. The methods employed included, CSAMT (controlled-source audio magneto-tellurics), airborne and ground elect-romagnetics, IP/resistivity and ground magnetics. The magnetic method was used as a regional mapping tool as well as a way of mapping alteration zones over both the Nena and Frieda River copper deposits. Electromagnetics, in part-icular FLAIRTEM, is a rapid reconn-aissance tool as well as a detailed mapping tool for the location of Nena-style massive sulphide deposits. IP/ resistivity is an expensive but most useful tool for mapping out Frieda porphyry copper style disseminated sulphides as well as Nena style deposits. It can be used to define drill targets in areas of difficult Access.a

Jan 1, 1994

The cloud transform simulation is a technique used to generate realisations of correlated attributes. The principle of this technique is to partition the scatter diagram between the input attributes into several interval classes and derive for each class a cumulative distribution function (CDF) using only the data pairs of the scatter diagram in that class. The simulation then proceeds like a traditional Monte Carlo simulation but using the derived CDF in each class.The cloud transform simulation has the advantage of being a simple and fast technique that is able to reproduce the uncertainty in the relationship between the two input attributes regardless of whether the relationship is linear or not. However, the technique has three major drawbacks. First, the number of classes has an impact on final simulated results and there is not a robust approach to define such number. Second, simulated results exhibit some saw tooth variations that are unrealistic and third the reproduction of the spatial continuity of the simulated attribute is not guaranteed.This paper presents the use of the quantile regression approach in order to overcome the first two disadvantages of the cloud transform simulation. Details of the technique and how it can be coupled with the cloud transform simulation are presented along with a real case study.

Sep 26, 2011

By A Creighton, C McKenzie

Blasting is a critical task in the development of an open pit. The formation of stable slopes is also essential to the safe and economic extraction of ore. The objectives of a mine blasting department are often considered to be in direct conflict with those of the geotechnical department. This should not be the case. Personnel in the various mining departments need to understand that their goals are the same û to optimise safety and cost-effectiveness of the operation. Blasting has the potential to damage rock that is to remain in situ by generating either excess vibration, and/or pressure. These damage mechanisms are described and guidelines with respect to blast design to minimise the potential for damage are given. A rock mass could be expected to be subjected to varying degrees of damage by blasting, including both intensity of damage and also the extent of damage. These issues have potential to impact significantly on geotechnical design considerations. It is therefore important for the practitioner to define what constitutes damage. In the context of mining, it is recognised that there is a need to balance the requirements for efficient excavation with those of forming stable and cost-effective pit walls. It is therefore important to have a set of key performance indicators (KPIs) against which the performance can be bench marked. These would include cost and time, both of which may be influenced by very diverse factors such as drilling, explosives and their performance, fragmentation, excavator and haul truck performance, requirements for batter clean-up and safe working practices. KPIs are identified and discussed in this paper.

Jan 1, 2003

By I Gipps

The mining industry has come through a period of major change in community expectations regarding safety and environmental impact and these changes can be expected to continue in the future. These changes are ultimately reflected in Government regulations and industry safety standards and form the basis of the ælicense to operateÆ. Equally, advances in technology have made possible new equipment and processes either available now, or close to completion, that will allow mines to meet these more stringent expectations if properly introduced. Changes in technology provide opportunities for mine management to introduce new systems that will remove people from hazardous areas and lead to improvements in the ætriple bottom lineÆ. In a longer time frame of five to ten years, novel and advanced technologies that are currently being developed will deliver new mining methods and conversion of presently uneconomic resources to ore. This is consistent with the time frame required to develop a new mine from discovery. Strategic decisions can be taken now by mine designers to enable the introduction of these major technology changes. Examples of both practical and strategic opportunities are drawn from the integration of rock cutting/blasting, automation, electronic communications and new mining methods. This paper discusses emerging industry trends, changes to legislative framework and some practical choices for existing and imminent technology.

Jan 1, 2003

By O Dominguez

Significant value can be added to ore supplied from the mine to the mill by measuring its quality in real time and performing grade control additional to that within the mine. Responsibility for ore quality between the mine and mill stockpiles is not always clear due to operational siloes so geologists and mining engineers need to be involved collaboratively with metallurgists to optimise ore value prior to processing. Sensors, such as the GEOSCAN-M which utilises high specification Prompt Gamma Neutron Activation Analysis (PGNAA), that measure conveyed ore flow representatively (continuous and fully penetrative) and in real time have been used in the minerals sector since 2003 and have been successfully applied in multiple commodities. Quality can be measured within the mine where material is conveyed underground or in-pit. Bulk ore sorting is used to divert increments of waste from the ore stream to upgrade material sent to the crushed ore stockpile (COS) as well as to create run-of-mine (ROM) stockpiles of different qualities to maximise blending opportunities and accommodate processing priorities, eg blending out deleterious content. The real time composition measurement can be combined with moisture and fragmentation analysis data for improved ore type characterisation, to control ore blending, for feedback to the mining schedule and block model reconciliation, and feed forward control for grinding and processing operations. The paper discusses various parameters measured and derived in existing operations that are used to maximise coarse waste rejection and metal recovery, optimise plant feed quality consistency, and reduce consumables; power, grinding media, water, reagents, and minimise fine tailings generation. Innovative geometallurgy applications are also discussed.

Mar 22, 2022

By Reed M. E, Cloutt B

Particulate samples were taken from the gas space in the settler of the Kalgoorlie nickel smelter using a vertical sampling probe and a specially designed isokinetic sampling probe which also quenched the samples. The vertical sampler was found to give unrepresentative samples. Suction thermocouple measurements of the gas temperature were also made. Using the isokinetic probe samples were taken at four points ranging from near the base of the reaction shaft to the base of the uptake at depths up to 1.5 m into the settler. Dust loadings and the sizing of the samples were determined. These parameters were found to be most affected by sample position and depth. The dust loading decreased along the settler but increased with depth. The loadings varied from zero near the roof to several hundred g Nm 3 near the slag. The dust also became coarser with increasing depth into the settler. Examination of the samples showed them to consist of spherical particles the largest of which were about 500 microns in diameter. The dust was mainly composed of mixed iron/nickel oxides with a little sulphide.

Jan 1, 1991

By F F. Pitard

Observation from attending many conferences around the world reveals that many people are constantly shifting from the word ‘error’ to the word ‘uncertainty’ without a clear vision of what the subtle difference is. The same applies to a large swath of the scientific literature, in which these two concepts are unfortunately often used synonymously, which is a scientific flaw of the first order. In practice, as demonstrated in the Theory of Sampling (TOS), there are both sampling errors and sampling uncertainties. Sampling errors can easily be preventively minimised, while sampling uncertainty for a preselected sampling protocol is inevitable. P M Gy’s work, supported by G Matheron’s critical reviews, demonstrates beyond any possible doubt that sampling uncertainty cannot be achieved if sampling errors are not preventively minimised by applying very stringent rules that are too often ignored by sampling practitioners. A clarification, in line with the TOS, is presented to mitigate the confusion created by circles favouring the use of uncertainty versus the use of the word error. Both words are very different in nature and scope and they are both necessary in their due place and time.CITATION:Pitard, F F, 2017. From errors to uncertainty – a clarification for proper use by the Theory of Sampling, in Proceedings Eighth World Conference on Sampling and Blending , pp 355–358 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

The addition of a thallous salt to the cyanide leach of a calcined pyritic concentrate causes a marked increase in the"rate of extraction of gold. This probably is due to the activation of passive gold by.th,e. thallous ions'.''Lea'd, bismuth, and mercury salts, which should produce ' a, similai effect, fail to do so. It is postulated that'this latter result, together with'the reprecipitation of silver at low cyanide levels, is due to the presence of soluble sulphide. The use of thallous salts to reduce leaching time is discussed briefly.

Jan 1, 1964

By A Bonani, R Molina, H Constanzo

With conventional undercutting sequence the infrastructure on the production level often has a short serviceable life before major rehabilitation is necessary and is characterised by high maintenance costs. The abutment stress zone is the main cause of this situation. The application of the pre-undercut caving method variant can increase the availability and utilisation of the production level When a pre-undercut is used development and construction are carried out underneath a previously undercut area, far away from the abutment stress zone, under more favourable stress conditions. This paper describes the design principles and the relevant results from the application of the pre-undercut variant over three years to the Esmeralda sector of El Teniente mine. The aspects described are the undercut-extraction, the undercut-development and construction distances, the geometry and drawbells opening, cave extraction rates, and the rate and height of undercutting.

Jan 1, 2000

By Tonks E. E

The earliest discovery and mining of coal in the northern area of the Greta Coal Measures at Anvil Creek in 1862 was by William Farthing, however, some official records attribute the discovery to Thomas Frost in 1864. Frost's discovery was examined by William Keen, government examiner of coalfields, and further prospecting was carried out. This was followed by the pioneering work of C S Wilkinson, government geologist in 1884. Subsequently in 1886 C S Wilkinson entrusted a detailed survey of the coalfield to the then geological surveyor, T W Edgeworth David.The outcrop of the Greta Coal Measures around the Lochinvar dome was mapped by Edgeworth David and as soon as he reported his discovery, the Department of Mines reserved in the interests of coal mining an area of 23700 acres, which extended between what became the South Greta and Abermain No I Collieries.

Jan 1, 1993

By I M. Platten, S C. Dominy

The evaluation of historical goldfields is currently topical, reflecting a high gold price, improvements in knowledge and technology. and lack of greenfield sites. Many goldfields comprise narrow gold-quartz veins which are structurally complex with an irregular distribution of gold; variable geometry and architecture; and display late deformational effects. The study of historical mine records can be an important tool during early and advanced project evaluation since it contributes to understanding the orebody, exploration target size and setting expectations. The historic Engineer Mine property is located 32 km west of Atlin, British Columbia on the east side of Tagish Lake. The economically important Engineer and Double Decker veins belong to a NNE-SSW vein set. These are narrow, commonly <2 m dilational veins with a minor sinistral strike component and of an epithermal type. Documented ore production between 1910 - 1952 is recorded as approximately 14 263 t at 39.4 g/t Au and 19.5 g/t Ag (for 18 000 oz Au and 8950 oz Ag). The underground workings consist of about 5500 m of tunnels, shafts, raises and stopes over eight levels. The mine is currently being re-evaluated. In 2011, an Inferred Mineral Resource of 41 000 t at 19 g/t Au for 25 000 oz Au (at a 5 g/t Au cut-off) was defined from historical data supported by modern drilling into the Engineer and Double Decker veins. A surface and underground bulk sampling and milling program was undertaken in 2011.CITATION:Dominy, S C and Platten, I M, 2012. Application of historical data to estimate a mineral resource at the Engineer gold mine, British Columbia, Canada, in Proceedings Narrow Vein Mining 2012 , pp 81-100 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By Nickelsen J, Theisen KG, Hansen PH

The use of stationary calciners in the processing of aluminium hydroxide has emphas- ized the importance of Bayer hydrate properties with respect to particle breakdown during calcination and subsequent treatment. Test results from calcination of several Bayer hydrates to sandy alumina in the FLS Gas Suspension Calciner (GSC) were obtained in a 250 kg/h pilot plant unit. Particle breakdown during calcination was influenced by content of solid sodium oxalate, trapped in the hydrate particles and operating gas velocities. Owing to the design and operational principles of the GSC it is possible to reduce particle breakdown to at least the same as what is found in long rotary kilns. Other major advantages reviewed are obtained through simplifications in plant design and operation, pointing to low specific power and heat consumption, and generally low production costs, thereby providing an attractive alternative to fluid-bed calciners.

Jan 1, 1981

Arrow Energy NL has been operating a number of coal seam gas wells in the Darling Downs region of Queensland. At the time of writing this paper, the region is enduring an extended drought period. The local aquifers are depleting and have not been significantly recharged in over a decade. The local communities (both rural and townships) are struggling to obtain water. Currently, coal seam gas (CSG) operators (under licence) draw water from the coal seams as part of the gas production process and the majority of operators choose to evaporate this water, as it is characteristically brackish to saline in quality and as such must be contained. Although the water produced from one CSG operator is not sufficient to drought-proof the greater area of the Darling Downs, there is potential to supply smaller local areas and contribute to the sustainability of these communities. This paper outlines the work completed by Arrow and its local community partners on the Darling Downs to date, and discusses the application of the produced formation water for:stock watering in feedlots, as a feedstock for coal washing, as a potable water supply for Dalby, as an agricultural water supply for cotton farming, and use as a medium for growing salt-water fin fish.

Jan 1, 2006

By A Bagis, T Baker

In 1983 the New South Wales (NSW) Government began to construct a 35 km freight rail line to provide additional rail capacity to Port Kembla in the Illawarra region, south of Sydney, through a direct connection between the Unanderra to Moss Vale line at Dombarton to the Main South rail line at Maldon in the Southern Highlands. The project area lies within the carefully managed Sydney Water catchment and is also underlain by previous coal mining activities.Construction of the line halted in 1988 prior to its completion after the NSW Government reassessed the demand case and found that the project was not as viable as originally forecast. However, by this stage the line was partially constructed, including the majority of civil earthworks, approach structures to the main river crossings and establishing the portals for the Avon tunnel as a precursor to major tunnelling works.In 2012, the Commonwealth Government funded Transport for NSW to undertake the necessary engineering and environmental preconstruction works. Most importantly here, the 1980s rail link was predicated upon the use of electrically powered locomotives, whereas the locomotive fleet in operation today in NSW is diesel powered. This fact has a significant impact upon the approach and development of the Avon tunnel section, as the diesel powered locomotives combined with the length and grade of the tunnel alignment produces a unique set of conditions requiring specialist engineering design and systems to ensure safe and functional operation of the railway through the tunnel section.Given the above, the Avon tunnel will need to be supported by a ventilation and smoke control design based on the heat rejection from the locomotive consist, consideration of ambient air quality compliance, comparison against in-tunnel air quality goals, and providing safety systems in line with the fire and life safety strategy it requires.This paper explores the current development of both the tunnel civil works responding to the geography, geology, rail functional requirements, as well as the tunnel ventilation systems being revised to suit the diesel locomotives.Further, this paper describes the importance of combining the design outcomes with the procurement methodology in order to achieve the project objectives, a functional outcome and value for money across the project life.CITATION:Baker, T and Bagis, A, 2014. Maldon to Dombarton Rail Link – design development of the Avon Tunnel, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 487–494 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By J Harmse

This paper deals with the modernisation of the brakes on an electrically coupled Blair multi-rope hoist and covers the removal of the old calliper brakes and hydraulic control system, and its replacement with brake discs, disc braking units and hydraulic control systems. The paper covers the braking requirements of the hoist, which is made up of two electrically coupled single-drum hoists, together with the theory behind the choice of brakes and control systems supplied. The paper also covers the project logistics that were required in order to install and commission the new brakes and control systems with the minimum disruption to production on the only rock hoist on a major production shaft. Items covered include the modifications to civil works, pre-installation of bearing lubrication systems, brake discs and hydraulics and the interfacing of the new hydraulic control system to the existing electric control system. It had to be designed to be compatible to a new electric drive and control system due for installation at the end of 2005.

Jan 1, 2005

By M Byrne, P Newman, M Lindqvist

SomincorÆs Neves Corvo Mine, one of the largest copper producers in Europe, is currently constructing a paste backfill plant in order to replace cemented rockfill in its bench and fill stopes and possibly replace hydraulic sandfill in the drift and fill stopes. A 250 m flow loop was constructed at the mine and the flow properties of various paste blends were investigated. Cycloned tailings and total tailings were both pumped successfully as pastes and were also combined with waste rock for additional testing. The pressure losses in 102 mm and 154 mm diameter pipeline were recorded at flowrates up to 60 m3/hr and are presented at slumps from 120 mm to 250 mm. The data showed the sensitivity of paste mixtures to slight changes in consistency, confirming the need for accurate control during paste production and distribution. The flow results clearly showed the different paste behaviour between cycloned and total tailings pastes and the change in properties at low and high slumps. In addition to pressure loss data, strength testing was done on 38 mm and 82 mm diameter samples. Further strength testing is ongoing at the mine using fly ash as a supplement to cement, reducing the overall binder cost. Preliminary engineering for the underground distribution system is briefly discussed, with reference to the siting of the plant. The Neves Corvo Mine is particularly shallow and alternative methods to pumping were sought in order to ensure sufficient hydraulic head for underground distribution. The comparison of options had to take into account the capital and operating costs, the operation of the plant and the impact on the future expansion of paste fill utilisation at Neves Corvo.

Jan 1, 1998

By S M. J Koleini, F Hedjazi

The purpose of this research was to study the calcination of lead-zinc flotation tailings from the Angouran lead and zinc flotation plant in Iran as a pre-concentration step prior to hydrometallurgical processing of the oxidised tailings. There is an abundance of these tailings in the Angouran region and making use of these tailings would help preserve national wealth and also reduce the serious problems of environmental pollution caused by the tailings. At the optimal conditions of calcining at 750 - 800¦C for 45 minutes, the sample showed a mass loss of about 19 per cent. Mineralogical analyses showed that under these conditions the carbonate minerals including smithsonite (ZnCO3), calcite (CaCO3) and dolomite (Ca Mg (CO3)2) decomposed to their respective oxides. Hemimorphite (Zn4Si2O7 (OH)2.H2O) converted into willemite (Zn2SiO4) and this transformation postponed the formation of silica gel in the leach solution. The grade of zinc increased from 22.20 per cent to 29 per cent. These mineralogical changes resulted in desirable reactions in the acid leach process.

Jan 1, 2004

By T Sirinawin, R H. Murfitt, W Shywolup

The Bong Mieu Project lies within the Pre-Palaeozoic Kontum Craton near the southern margin of the regional Phuoc Son û Tam Ky Suture. The Suture and accompanying Truongson Fold Belt of Indosinian age host significant gold and base-metal bearing districts including OlympusÆ other project at Phuoc Son to the west of Bong Mieu and OxianaÆs Sepon project in Laos. The Bong Mieu Project is located some 90 km south of Da Nang and some 30 km south-west of Tam Ky, the provincial capital of Quang Nam province in central Vietnam. The project area is covered by an Investment Licence of some 30 km2 which was granted in 1991 and a mining permit of some 365 ha granted in 1992. Several mesothermal, gold-silver deposits with assigned resources are present on the property. Deposits with assigned resources contain some 615 000 ounces of gold in situ. These are at Ho Gan and Ho Ray which are potentially exploitable by open-pit mining and Nui Kem which is potentially exploitable by underground mining. Newly discovered extensions to the known deposits at Ho Gan, Ho Ray and Nui Kem, and several other new prospects, are currently being investigated by drilling. The Ho Gan mineralisation is of mesothermal, shear and shear breccia quartz vein, as well as intrusive breccia hosted style. Nui Kem mineralisation is of mesothermal, shear and shear breccia quartz vein style. The Ho Ray mineralisation is of skarn (gold-bismuth-tungsten) and lesser quartz vein style. The deposits straddle and flank the east-west trending Bong Mieu Anticline which trends through the central portion of the Investment Licence. In this paper the geology of the deposits, details of resources, results of recent exploration on the Investment Licence and recent engineering and mining studies at Ho Gan are briefly reviewed.

Jan 1, 2004

By Brown DJ, Croghan JA, Denby B

The paper describes the development and analysis of an instability database to establish a new method of slope stability assessment for U.K. surface coal mines. The concept is based upon a Stability Index, which relates to the probability of failure of a slope. This forms the basis for a geotechnical planning software package to be incorporated into a computer aided mine design system , which is currently under development.

Jan 1, 1986