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By E Nye and T Schroeter, B Muir, M Kitson, M Gonzalez, D Mares

The single track North Strathfield Rail Underpass (NSRU) consists of a dive structure either end of a 148 m long driven tunnel skewed under three live railway tracks. The tunnel is 8 m high, 9 m wide, with a horseshoe profile, excavated by full face using a road header. Ground cover varied between 2.5 m to 3.5 m. Settlements were 5 mm to 15 mm (the latter due to a dyke). A one pass synthetic fibre reinforced shotcrete lining was installed (no lattice girders or steel sets were used). A system of automated robotic total stations was used to provide real time monitoring of the rail track and associated ground formation. No disruption to train services occurred.CITATION:Gonzalez, M, Kitson, M, Mares, D, Muir, B, Nye, E and Schroeter, T, 2014. The North Strathfield Rail Underpass – driven tunnel design and construction, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 369–374 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By W Skinner, C G. Kelsey, J R. Kelly

The iron ore industry has reached the end of an unprecedented period of expansion triggered by China’s demand for iron ore. Lower ore prices have led producers to focus on optimising mining operations while extracting the maximum tonnage from the infrastructure presently in place or from projects already underway. A rising global surplus is expected to further force ore prices down and lead to output curtailments, which in turn will help to restore market balance. However, investment in the development of new resources and the development of new infrastructure will inevitably become necessary. Making the right decisions in relation to future processing infrastructure in a climate of uncertain demand and price volatility will not be as straightforward as in the past, where expanding the scale of a proposed operation has been the answer to ensuring economic viability. Overall cost and environmental pressures particularly in relation to wet processing will dominate the decision-making process. IMP Technologies (IMPTEC) has anticipated the need for a dry low cost processing alternative, which can open the way for the development of lower grade magnetite deposits and ensure the sustainability of processing in Australia. The lower grade magnetite deposits are generally fine grained and require grinding to p80 of 30 to 40 microns. Historically, the cost of grinding to these sizes has been and remains a key factor determining the economic viability of a magnetite processing operation. The IMPTEC Super-fine Crusher and Cyclomag Separator are the key components of a proposed radically simplified dry processing alternative, which addresses both cost and environmental issues. This paper reports on the results of pilot super-fine crushing and cyclomag separation test work, focused on supporting the feasibility of the proposed dry processing route for the production of high-grade pellet plant feed from fine grained low-grade magnetic ores.CITATION:Kelsey, C G, Kelly, J R and Skinner, W, 2017. Dry processing of magnetic iron ores – addressing cost and environmental issues, in Proceedings Iron Ore 2017, pp 215–220 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Alfred Nobel first invented a practical detonator in 1863 and then the blasting cap in 1865. At that time the detonator was used on the end of a length of safety fuse to initiate nitroglycerine-based explosives. Since then the detonator has gone through a number of changes. The instantaneous electric detonator was the first to allow remote firing. The electric delay detonator followed and allowed for timing between holes. In the mid 1970s the NONEL« Tube was invented. This tube combined with NONEL« detonators meant that many of the safety issues, such as stray current and radio frequency, associated with electric delay detonators were eliminated. This system gave the mining industry a reliable and fairly accurate system with which to detonate shots of any size. Since the early 1980s a large amount of research and development work has been done around the world to create a more accurate detonator for the mining and quarrying industry. After years of research, electronic detonators have emerged as the most accurate and precise initiation system available to the mining and quarry industry today. Electronics provide the user with millisecond timing accuracy. The improved level of timing control allows operations to improve fragmentation, throw and reduce vibration levels. There are now a number of different electronic detonator suppliers on the market today. In 2004 Dyno Nobel formed a joint venture called DetNet with AECI. DetNet has a suite of electronic detonators: DigiDet«, HotShot« and QuickShot«. This paper will focus on the HotShot« system, the first of the three new initiation systems to be released to the market in Australia by Dyno Nobel.

Jan 1, 2005

The quantity, quality and detail of project information increases as project development moves from initial scoping level studies, to pre-feasibility and option studies, then definitive feasibility study and basic engineering stages. Data accumulates from metallurgical and vendor testing from various ore types and composites carried out to assess physical characteristics and processing responses of the ore. Over-simplification or assumptions about the orebody for flow sheet development can result in using æaverageÆ information for design. Use of averages of data can have adverse implications on sizing of plant and equipment and consequently on definitive study cost estimates and detailed engineering. In practice, the treatment plant workforce is faced with managing a non-homogeneous or non-average orebody in a variable operating environment that is not always predictable. This paper presents views on how to use the data generated from testwork in project development and for process and plant design. Examples of process design risk or operating risk are presented. Although this topic is applicable to the broad range of process design decision making in the minerals industry, this discussion references comminution, flotation and extraction processes for gold and base metal ores.

Jan 1, 2004

The Effect of Molecular Weight on the Adsorption and Efficacy of Polysaccharide Depressants

Sep 13, 2010

By Lightfoot BW, Wand PD, Towne DV

Sampling and e.m.f. probes were used in the liquid flow from the blast furnace and in the forehearth to evaluate the performance of the copper smelting system at E.R. & S. Significant variations in temperature, oxygen potential and copper content with slag depth and with position in the forehearth indicated that convective currents were causing considerable stirring in the forehearth. This was attributed to temperature fluctuations in the stream from the blast furnace, which resulted in colder slag being underlain by hotter matte. Tracer tests in the feed to the smelter and in the feed to the forehearth revealed considerable holdup of material in the plant and confirmed that the forehearth involved small scale turbulence but little large scale mixing. The results indicated that the copper content of slag continuously tapped from the forehearth could be lowered by at least 0.15% if better settling could be achieved and means of attaining this are discussed. As part of the investigation the recovery of copper from spent refractory bricks recycled through the smelter was evaluated. It was found that the recovery was high but it seems likely that the brick material is partly responsible for a build up of solid material in the forehearth.

Jan 1, 1981

By D J. Thobaven

Project financing challenges caused by declining commodity prices have heightened the need to improve project metrics such as minimising capital payback and maximising net present value (NPV). Khnaiguiyah Mining Company (KMC) recognised the need to improve early cash flows at their Khnaiguiyah zinc-copper project after initial studies showed the project could not provide the desired financial outcomes necessary to compete for investment dollars in the current market.A significant improvement to the project cash flow in early years was realised through simultaneous optimisation of cut-off grade, mining sequence and strategic stockpiling. This improvement was achieved by accelerating mining in the pits, stockpiling lower value material and feeding higher value material directly to the plant. The schedule required higher mining and stockpile capacities than the sequential mine plan although minimal change occurred in the definition of ore and waste as measured by tonnes and grade. The practicality of the strategic schedule was demonstrated by implementation in the production plan with excellent conformance.CITATION:Thobaven, D J, 2014. An application of simultaneous optimisation – improving the payback period of a zinc-copper open cut project, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 137–144 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By Met M, Orr C. W, Met B. E

As was mentioned in the last paper of this series(l), magnesium was added to lead with the idea that it would act as a de-oxidiser. The magnesium lead alloys give rise to an inter-metallic compound of the composition Mg2Pb(2) and it has some remarkable properties. It is known to disintegrate on standing in the atmosphere and it confers this property also on lead alloys in which it occurs. Magnesium forms a solid'solution with lead, and according to Kurnakow, Pogodin' and Vidusova(S) the limits of solubility are as follow...In conformity with the practice used in preceding series, the limit of concentration used in the present investigation was 0.1 %. Accordingly, it would be expected that all the alloys used would consist of the solid solution and the detrimental Mg2Pb would be absent. Whilst this was the case, it...

Jan 1, 1939

By E Westthorp

Final mine sealing of BMA’s Crinum North mine, near Emerald, Queensland was undertaken in December 2015. Due to the benign atmospheric environment at Crinum North, the Queensland Mines Rescue Service (QMRS) Górniczy Agregat Gasniczy (GAG) unit was utilised to reduce oxygen levels throughout the underground atmosphere as part of the final sealing process.The GAG was utilised by way of a vertical borehole from the surface to seam to successfully reduce oxygen levels throughout the underground mine workings. Application of the GAG unit enabled the underground mine to be classified as stable and inert within days of the GAG operation, and subsequently cease gas monitoring at Crinum North. The data and information obtained from this activity provides valuable information to the underground coal mining industry on successful application of the GAG in realistic situations.This paper discusses the strategy used for sealing, the assisted inertisation and the results obtained from the application of the GAG unit. It discusses both the overall results and gives a detailed review of the gas monitoring data obtained via the tube bundle and real-time system, both during and following the use of the GAG unit.Gas monitoring results obtained and the strategy used are critical to share with the industry to obtain a better understanding of how the GAG unit works, and how it can be applied for emergency preparedness, emergency response or planned inertisation.CITATION:Westthorp, E, 2017. A review of the strategy and gas monitoring results obtained during the use of Queensland Mines Rescue Service GAG unit at Crinum North mine, in Proceedings Australian Mine Vent Conference 2017, pp 309–318 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

Studying the ore textures in a discrete orebody is a novel approach to estimating liberation potential of the ore minerals present. As part of a PhD thesis, this project aims at classifying and quantifying the textures of the Hilton North orebodies, and at estimating their liberation characteristics.

Jan 1, 1993

By Higuchi K

Intorducing the hypothesis that the cause ,òi spontaneous combustion of coal is depending un the accumulation of heat produced by its oxidation, the authors derived the equation expressing the temperature change in a heap i fine coal. To solve the equation, thermal conductivity, specific heat and rate of heat ,eneration of fine coal (-48 mesh) were measured at various temperatures in the range _'0-65¦C. The equation was solved numerically and the volume of fine coal which would ignite spontaneously was estimated as the function of ambient temperature. Using 170 Kg of fine coal, everal experiments for confirmation were conducted. At the ambient temperatures of 60¦C nd 50¦C, coal began to fire spontaneously brut 00 and 110 hours later respectively. Iii addition to this, the measured t,,rp,i,itures in the coal heap agreed with the ,aLulated ones comparatively well, If more volume of fine coal were used, experi;:ontul ;,eneration of spontaneous combustion from ...,n-, , 1-1 I'd Sill al r..

Jan 1, 1981

Commercial or potentially commercial deposits of coal occur in Australia in strata ranging in age from Permian to Tertiary. The coals of each period tend to show a community of petrographic character and significant differences as compared with coals of other ages. In particular- many of the Permian coals are unusually rich in inertinite whereas the Jurassic and Tertiary coals are typically very rich in vitrinite. The majority of the coals show evidence of deposition in environments subject to relatively minor marine influence. Except for some Tertiary and Permian coals the content of mineral matter tends to be high. Outcrops of coals of bituminous rank appear to be largely restricted to the eastern margin of the Australian continent. In this region vertical rank gradients are generally higher than in the other sedimentary basins and uplift and the removal of cover has occurred to a greater extent. To the west of the Tasman geosyncline, coal of bituminous rank generally occurs at considerable depths (usually in excess of 1 km and in some areas only at depths of over 2 kms), and in most areas coals at shallow depth are of sub-bituminous or brown coal rank. The controls of the distribution of coal type and rank have considerable economic significance and the unusual characteristics of Australian coals, especially with respect to coal type, make the direct application of overseas technology to Australian coals inappropriate.

Jan 1, 1975

By Haeussler P, Christie A, Bradley D, Skinner D

Mesothermal gold deposits of southern Alaska and Westland, New Zealand have both formed at the seaward edge of major collisional zones in the Pacific basin. In Alaska, production of large fluid volumes correlates in time with the addition of heat into the lower parts of the accreted terranes in the late stages of collisional orogeny. This heat was critical for driving both the metamorphic reactions that released the large volumes of fluid that carried the gold, and the contemporaneous widespread anatexis and magmatism. In Alaska's Chugach terrane, this heat was produced by subduction of a spreading ridge beneath the North America continental margin in the Eocene. The resulting products were the S-type granites and gold-bearing veins. The similar widespread S-type plutonism and gold veining in Westland's Buller terrane suggest that a similar tectonic event could have triggered ore formation along the southeastern edge of Gondwanaland. Based on the Alaskan model, a Devonian or Early Carboniferous age is favoured for high volume metamorphogenic fluid generation and gold vein formation in Westland.

Jan 1, 1995

By R G. Jeffrey

The Northparkes, Endeavour 26 orebody is a porphyry copperûgold deposit and comprises a moderately to well jointed rock mass characterised by gypsum veining, the intensity of which decreases with depth. The top 480 metres of the orebody is currently being mined by block caving, the undercut dimensions measuring 196 metres in length by 180 metres in width. Continuous caving was never achieved after the completion of the undercut thus cave inducement techniques were sought to maintain caving so as to safely sustain production. The use of hydraulic fracturing as a cave inducement tool was successfully trialled in December 1997 using existing exploration boreholes located midway up the current lift. Subsequent fracturing campaigns have enjoyed various degrees of success and have yielded in excess of seven million tonnes of ore at a significantly lower cost than conventional cave inducement techniques. Monitoring of both the hydraulic fracture system and the rock mass response has provided considerable insight into the geometry, growth and influence of hydraulic fracture networks above the Northparkes block cave, and has initiated additional research into the use of hydraulic fracturing in other mining methods.

Jan 1, 2000

By Edmonds W, Giles C. W, Webb R. J, Gum J. C

Gold production from The Granites - Tanami Goldfield during 1993 is expected to exceed 8 t, eclipsing that of the traditional Northern Territory gold mining districts of Tennant Creek and Pine Creek. This is the result of dedicated and successful exploration, and the consequent discovery of new orebodies such as those at Dead Bullock Soak.Following granting of access to regional exploration areas in 1988 and identification of favourable host rocks in the Schist Hills area, North Flinders Mines (NFM) began a methodical exploration program of detailed geological mapping, rock chip sampling, costeaning and various types of drilling. The first resource of 600 000 t of 3.3 g/t gold was announced in mid-1989. This has grown progressively with systematic exploration to the currently published resource inventory of 6.6 mT @ 5.4 g/t, (as at 31.12.92) contained in six separate orebodies within the Dead Bullock Soak Mineral Lease at Schist Hills.

Jan 1, 1993

Sheaves are a critical safety component in a winding system and are expected to survive such extreme loading events as rope break. Sheave designs have often been developed and evolved empirically, consequently many existing sheaves are not necessarily subjected to the detailed analyses that are possible using todayÆs design tools. The design philosophy for sheaves is that the rope should be the weakest link in the system so that associated equipment can function safely for any load up to rope break. A number of failure mechanisms must be considered, but buckling is often prominent. During the course of investigating the feasibility of upgrading the hoisting capacity of a winding system, the capacity of all critical components was reviewed. The sheaves in the system were found to have insufficient spoke buckling capacity for the specified rope. A proposal to increase the spoke buckling capacity by connecting spokes together using a simple tie arrangement was evaluated and found ineffective. An alternative tie arrangement concept was developed and evaluated and shown to be adequate. This paper describes the finite element model, analysis approach and results for the original sheave and the two modifications. The contribution of the sheave rim to the total buckling capacity is evaluated. Some practical issues for spoke tie modifications are discussed.

Jan 1, 2005

By Estoque J, Lodrigueza L, Rebillon F

Ore mineralization in Masara consists mainly of gold-silver veins, porphyry copper and pyrometasomatic deposits related to left-lateral movements along the Philip- pine fault system and a later stage of magmatism. These are hosted by pre-Tertiary volcanic flows and volcaniclastics, and comprise a temporal pattern of earlier peripheral copper zone, an intermediate mixed copper-gold area and a later central gold vein system within the Masara sector of the postulated volcanic field. Gold ore emplacement occurred in at least two stages, and shows gradations from a lower mesothermal-epithermal phase passing into a typical epithermal zone, and finally into a truncated, or poorly developed, upper level thermal spring deposit. Orebodies are closely associated with hot springs, solfatara and several magma- related masses, emphasizing their inherent linkage with a geothermal system in the Area.

Jan 1, 1987

Mine planning studies of iron ore deposits are often based on resource models generated by ordinary kriging. Ordinary kriging aims for local accuracy to minimise the variance of expected estimation error but this is at the expense of reproducing variability of the original sampling data. Hence mine planning studies using kriged models are likely to underestimate product variability, and the required blending and stockpiling capacity to reduce variability to an acceptable level. Instead, conditional simulation models of the main chemical variables in iron ore are able to reproduce likely variability to be encountered during mining and processing. This approach is demonstrated in a case study of the Weld Range bedded iron ore deposit in Western Australia, with a comparison of ordinary kriging and conditional simulation models. Conditional simulation models suggest that, compared with the single ordinary kriging estimation, there is likely to be far greater block variability for iron and impurities, a greater requirement for stockpiling and blending capacity, highest variability in initial years of mining and less variability in later years of mining for deeper ore. The conditional simulations provide a more realistic range of mining outcomes for production of high-grade ore, which may be seven per cent less than in the kriged model, as well as for lower expected project net present value (NPV). In year one, the kriged model is conservative for NPV; however, in later years two to five the kriged model has higher NPV than most conditional simulations, suggesting expected NPV based on the kriged model may not be achieved. For improved decision-making in mine planning, a complete range of possible outcomes from conditional simulations of the deposit should be considered rather than relying on a single kriging estimation that may be an end member case in the range of possible mining outcomes.

Jan 1, 2009

The use of pipeline-c to carry crude'oil and petroleum pro-ducts is a reliable and economic*Way to transport large quantities of oil. The length and size of these pipelines have continued to grow throughout the world as the demand for petroleum has in-creased and as the price of other transportation-methods has risen. At the present time pipelines 'can move a barrel of oil a distance of 100 miles at an average cost of ,80.06 U.S. dollars.The major elements in pipeline design are discussed. Methods of calculating pressure drop and horsepower requirements are pre-sented. These are variations of standard equations.in which the elements of each equation are expressed in terms common to the petroleum industry. Major equipment is discussed., particularlyas it relates to operation and economics.Cost data are presented to aid in preliminary economic ana-lysis. Curves illustrate the cost of oil transportation at flow rates between 10,000 and 500,000 barrels per day and permit the selection of pipe diameter-which will result in minimum operating costs.

Jan 1, 1962

Exploration for uranium in Australia commenced only during the 1940s, but in this short period has been very successful as one third of the world's low cost uranium reserves have been discovered in Australia. Total uranium exploration expenditure in Australia up to the end of 1983 was $A(1983) 554 million; this discovered 20 potentially economic deposits and official reserves of 560 000 tonnes of uranium oxide at an average cost of $1 per kg of U 0 . An exponential 8 eserves indicates distribution of uranium r that there could be 54 undiscovered uranium deposits in Australia, each with reserves of 20 000 tonnes U308 or more, in addition to smaller deposits. Using a constant uranium price of $A(1983) 79 per kg, no deposit is economic at a grade below 0.12 per cent U 08 or with reserves of less than 3 000 tonnes. Selecting deposits with reserves of 5 000 tonnes U 0g or more as prime exploration targets, only 39 per cent of discoveries will yield a real internal rate of return (IRR) of 10 per cent or more. After committing a minimum exploration budget of $10 million to this search, an explorer has one chance between 7 and 12 of discovering a deposit that will repay the exploration investment.

Jan 1, 1984