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Detailed observations were made for two existing continuous miner and shuttlecar systems. A simple model for the shift average cycle consisted of three time components - delays, mining and transport. Cycle improvement and productivity improvement factors are derived and used to predict the theoretical improvement which the observed cycles could achieve. Various strategies of action ranging from short-term optimisation through to long-term planning for continuous haulage systems are evaluated. High potential for improvement is shown for a wide range of operating conditions. An overview is presented for systems, currently available or under active development, which can accept coal directly from continuous miners and offer continuous haulage to the surface. Systems are broadly classified as mechanical-roof mounted, mechanical-floor mounted and hydraulic transportation.

Jan 1, 1982

Any project carries a number of challenges and risks. Inappropriate design, poor project management, time, industrial disputation and capital over runs are all areas which can impact on a project cash flows and return on investment. In the resource Industry you have the added complexity and risk of geology which is difficult to predict and sometimes unforgiving. The Dartbrook Mine was designed and constructed as a high output longwall mine and has overcome a number of hurdles to produce over 2.3 million tonnes for the first year of operation. A number of problems were encountered during construction which resulted in the inseam development being delayed for six months. Dartbrook people have demonstrated they can manage adversity and produce world class results. The mine has been through a very steep learning curve during 1997 and with this experience behind the mine is now producing at an annualised rate of 3.4 MTPA.

Jan 1, 1998

The Lake Rotokaua sulphur deposit, near Taupo, New Zealand, is a lacustrine sedimentary ore body, 220 acres in area and from 7 ft to 96 ft thick, containing, within the area drilled to date, some 20 million long tons of ore averaging 25% elemental sulphur in unconsolidated tuffaceous diatomaceous clay, overlain by about 120 ft of pumice sand and by the shallow Lake Rotokaua. An additional amount of perhaps 4 million tons of sulphur is regarded as probable in the area remaining to be drilled. Current economic studies cover the problems of mining an unconsolidated water-saturated formation with some residual thermal activity nearby; conservation and restoration after mining in a scenic recreation area; beneficiation of the ore and extraction of high- purity sulphur, principally for fertilizer manufacture. The deposit has additional importance as a pointer to possible further discoveries in the Thermal Region.\

Jan 1, 1971

By P McGavin, R von Varendorff

With the economic trend towards reduced capital spend, more stakeholders are focusing on improved operational efficiency and productivity. Advancements in achieving the optimum dollar-per-tonnage will be more dependent on creating a logistics system that is well balanced and economically optimised. Critical to predicting a successful business case is the ability to accurately define capacity, realistically increase throughput and proactively translate objectives into design and operating requirements. Failure to do this will create an unrealistic perception of capacity and performance for the export corridor. This transition requires a fundamental understanding of the drivers that impact capacity, cost and value across the entire logistics chain. Through examples, this paper will identify the contextual requirements for simulation models that assist decision-makers and stakeholders to more clearly understand the implications of decisions that will define capacity and operational performance. The aim of this approach is to provide a rigorous analysis of the outcomes - regardless of whether the export corridor is owned, used and operated by one entity or various companies.CITATION:von Varendorff, R and McGavin, P, 2013. Can we live up to the capacity expectations weÆre predicting for our iron ore export corridors?, in Proceedings Iron Ore 2013 , pp 553-560 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By Goto T, Sato K, Mori N

A field investigation by making use of the seismic method has been carried out in order to comprehend the mechanism of rockburst and gas outburst and their predictive measures. The seismometers were so arranged both on the surface and underground as to enclose a mining panel. Seismic signals detected by the array were recorded and processed by the 32-kwords computer system. At present the system is available for analysing the source location and Richter's scale of each event and for visualizing the distribution of seismic foci and released energy at any mining stage. The magnitude distribution of events can be regarded as a comparable index of the seismic activities among mining panels. An analysis of the spatial density distribution of seismic energy in the mining panel can be useful to distinguish a highly stressed zone from stress released areas. The energy released curve or the rate of energy release determined from seismic data is also a good indication of the seismicity.

Jan 1, 1980

By Moorrees C

Tests show how that temperature and rate of sparging to remove carbon dioxide determine the rate of precipitation and the chemical and physical properties of hydrated magnesium carbonates precipitated from clarified magnesium bicarbonate liquors derived from crude magnesia. At temperatures above 55°C the product is largely in the form ofhydromagnesite, Mg5(C03)4(OH)2.4H2O Between I5°C and 55°C the major product is nesquehonite, MgCO3·3H2O, although partial hydromagnesite precipitation can be induced by a high rate of aeration.As a result of the reduced time required to bring about greater than 95 per cent magnesium precipitation, the higher MgO content of the product, the ease of product recovery from the precipitation vessel, and the lower energy requirement for thermal decomposition of the precipitate to magnesia, it is preferable to precipitate hydromagnesite rather than nesquehonite. Moreover, the magnesia produced from hydromagnesite is somewhat more reactive than that formed from nesquehonite.Using precipitate calcination temperatures less than 1000°C, the chemical reactivities of the magnesias formed from both precipitates are greater than those of the crude magnesias derived from Savage River magnesite itself. The magnesias would be suitable for most uses developed for caustic-calcined magnesia. However, for refractory brick manufacture, it would be necessary to briquelle the caustic-calcined magnesia. adjust the CaO and SiO2 contents and sinter at temperatures in excess of 1600°C. This would bring about an increase in the bulk density and induce the appropriate chemical bonding reactions.Dead-burned magnesia produced from Savage River magnesite by the calcination/carbon dioxide route would have very low B2O3 contents, typically less than 0.0001 per cent.

Jan 1, 1985

By Gleadow AJW, Foster DA, Kohn BP, Raza A

A large and increasing data base of apatite fission track results from sedimentary and granitic rocks exposed within the southeastern highlands and along the continental margin of Australia provides constraints for the tectonic development of the southeastern passive margin. The fission track results suggest that many regions of the southeastern margin of Australia experienced distinct episodes of relatively rapid cooling during the middle Cretaceous to early Tertiary that can be attributed to the effects of rifting. One cooling episode is middle Cretaceous in age and related to denudation of the southeastern highlands from Tasmania to northern New South Wales between -90-100 Ma. Rocks exposed along the present coast line record a later episode of rapid cooling, which is diachronous and decreases in age northward from -80 to 90 Ma in northern Tasmania to southern New South Wales, -60-80 Ma in central and northern New South Wales, and to -50-60 Ma in southern Queensland.

Jan 1, 1995

By Krzystanek Z, Wasilewski S

The problem of automatic control of a coal mine ventilation network is discussed. It is found that the structure of the control sys-tem should have two levels, i.e. local regulation of ventilation para-meters (air flows) in faces to eliminate the effect of quick disturba-noes, and supervisory control of the whole ventilation process by pe-riodical modifications to the working characteristics of the main fans. Practical and theoretical problems connected with implementation of the system in Polish mining are listed and discussed. To solve these prob-lems a series of experiments with air flow control in three different coal faces were carried-out with the aim of checking the measuring and control equipment in a real mine conditions as well as investigatingthe gasodynamics of the ventilation process. The results of the experi-ments are analysdd, and used to verify the mathematical model of the gasodynamics of a longwall face.

Jan 1, 1985

By J Gutzmer

The Kalahari Manganese Deposit in South Africa accounts for 80 per cent of the worldÆs land-based mineable Mn reserves. Although the ores are primarily mined for export, South Africa is the worldÆs third largest producer of ferromanganese and ferrosilicomanganese alloy, both of which are derived from the smelting of these ores. Mineralogical analysis has traditionally been forsaken for bulk chemical assaying in quality control of smelter feeds, principally because quantitative data could not be easily produced. Yet, mineralogy plays a vital role in determining smelting behaviour, which in turn has economic implications when aspects such as energy and reductant consumption are considered. Smelting is an endothermic process, and the amount of energy input required is dependent on the minerals present in the ore, as well as their relative proportions. Further, knowing the bulk Mn oxidation state in the ores allows for calculation of the amount of oxygen that must be driven off to produce alloy, and hence the amount of reductant required. Additionally, certain minerals can be correlated with potentially deleterious elements, so that ore mineralogy can indicate penalty element distribution. Mineral abundance analysis was conducted on ores from the Kalahari Manganese Deposit using quantitative X-ray powder diffraction. Rietveld refinement using a fundamental parameters approach was applied to micronised ore samples. The mineral percentages obtained were validated using mineral chemical data together with bulk major element data derived from ICP-OES. Bulk oxidation state partitioning was then carried out knowing the Mn valence in the minerals. The results show potential for implementation of the proposed method on a smelting plant, where ore blending could be then implemented to achieve consistent feed compositions to smelters. Selective mining could also be undertaken to obtain desirable ore compositions for domestic or international markets.

Jan 1, 2008

By Singh TN

Rampura-Agucha Zinc-Lead deposit is unique as it is reported for the first time in the gneissic terrain with a rich oregrade quality of early to middle Proterozoic of Bhilwara supracrustal belt in the Precambrian of Northwest India. These sulphide ores are mostly confined to the graphite bearing Quartzofelspathic gneisses with intermittent bands of Calc-Silicate granofels and amphibolite. The ore and country rock mineralogy and their textural features are indicative of highly metamorphosed deposit and further the presence of marmatite and monoclinic phyrrhotite revealed high temperature environment of deposition.The present paper deals with some of the ideas about the ore genesis and petrographics of the associated rocks for Rampura-Agucha Zinc-Lead deposits of Bhilwara District (Rajasthan).

Jan 1, 1990

By Morandini AF, Occella E, Clerici C, Mancini R

This contribution presents the first results of an experimental research aimed at finding an unified description of the first stages of a rock comminution process. With reference to the case of the jaw crushers and to the specific subject of the comminution law, the tests reviewed and analysed in this contribution have been carried out, at a laboratory scale, on five different materials (limestones, quartzite, serpentinite) at different reduction ratios and feed rates, and accurately recording both total power and idle running power. The analysis of the results has shown that: ò the grain size distribution of the products complies with a modified form of the Rosin-Rammler equation, already found to be well suited to representing the grain size distribution of blasted rock in previous works by the authors; ò observed trends of the consumed power at increasing reduction ratios is steeper than predicted by the classical Rittinger, Kick and Bond laws, Rittinger law representing however a closer approximation of the experimental results; and ò a more accurate description of the experimental results is provided by a modified form of the Rittinger law. Accuracy of the semi-empirical expression has been found to be usually better than ten per cent by comparing actual results with expected Results.

Jan 1, 1993

By Davey P. T, Tsambourakis G

Mineralogical analysis of supergene sulphide ore recovered from areas close to the underground workings at the abandoned Mutooroo (South Australia) mine shows that the original sulphide minerals have undergone substantial alteration. The cause of this alteration is believed to be contact with the highly saline, acidic mine water. The copper is now present as a sulphide that can best be described as a copper- and iron-delicient chalcopyrite, CuxFeyS2, where in most cases x < y. The values of x and y vary from point-to-point within each grain.Leach tests under a variety of conditions show that dissolution of the copper from the supergene sulphide ore can be readily achieved, particularly when compared with the behaviour of Mt Isa chalcopyrite concentrate. For the supergene sulphide ore, an increase in the acidity and the iron(lll) concentration of the leachant re ults in an increase in the rate of copper dissolution.The results are briefly discussed in terms of the experimental in-situ leaching operation at Mutooroo, South Australia.

Jan 1, 1986

By Houtgraaf M

The Far Fanning gold deposit is situated 60 kilometres south-west of Townsville (Fig. 1). Previous recorded production is 3756 tonnes returning about 1600 ounces of gold. This has been taken from surface and shallow underground workings- scattered over the strike length of the deposit of 1700 metres. The main production period was from 1895 to 1908.Previous exploration involving extensive trenching and sampling has been: carried out intermittently. since the 1930's, by Gold Mines of Australia (1932), Placer (1974), Anaconda (1975), Marathon (1980-8-1), Aberfoyle (1981-82), and The Northern Queensland Company (NQC) (1983-present).In 1980 Marathon undertook an extensive drilling programme to test the oxidised mineralisation. Over 200 percussion holes and- 7 diamond holes were drilled along traverse lines spaced 29 to 103 metres apart covering a strike length of around 1800 metres.

Jan 1, 1986

By K Li, C Zhang, i, J Oh, S Saydam, H L. Ram

Rock surface roughness plays an important role in excavation engineering projects and applications related to surface support structures, such as shotcrete and thin-sprayed liner (TSL). The morphology of the substrate affects the mechanical behaviour at the interface significantly. Therefore, it is necessary to quantify the roughness to investigate the relationship between roughness and mechanical properties. The joint roughness coefficient (JRC) proposed by Barton and Choubey (1977) is widely used in practice. It initially estimated the roughness by comparing it to 10 standard profiles visually. However, this method has lots of limitations, it is not only subjective but also a two-dimensional parameter with a small lab scale (Beer, 2002). The subsequent research on JRC, from visual comparison with Barton’s standard profiles to measuring the roughness with a profilometer (Weissbach, 1978; Alameda-Hernández et al, 2014). Then, 2D profiles or 3D surfaces by different technologies with higher resolution and accuracy, such as 3D laser or optical scanners (Fardin, 2004; Jiang, 2020, 2021). These 3D scanners are expensive and only suitable for laboratory scales. LiDAR scanners (Lato, 2009; Aubertin, 2022) have been applied in industrial size, but it is difficult to achieve a millimetre-level accuracy, which is mostly used to detect the thickness of shotcrete in practice. Thus, finding a cost-effective surface roughness measurement method with high accuracy is necessary. Photogrammetry is another method to digitalise the roughness of the surface. Similar to 3D scanners, photogrammetry also generates the point cloud of the objective surface and then reconstructs the 3D model of the objects. 3D reconstruction technology is a trendy technology in recent years. The structure from motion (SfM) algorithm (Westoby, 2012) to rebuild the 3D model with a flexible workflow, aligning photos, building dense point cloud, mesh and texture, which has been proved that can rebuild an accurate model in variable fields.

Nov 29, 2022

By Wilkinson RDB, Van Der Meer FP

In order to overcome the statistical limitations imposed by the need to recover density tracers by hand, magnetic density tracers were developed to determine the efficiency of dense medium separators treating porous materials. The tracers were manufactured by extrusion of polypropylene ferrosilicon mixtures and subsequently coated with a distinctive paint to allow hand sorting according to density. Fifteen tracer batches were manufactured in the range 1.61 - 1.94 g/cm3. The tracer densities were determined by a hydrostatic method. The tracer method was applied to the dense medium separation of a Moroccan oil shale in a pilot scale Dyna Whirlpool separator. For each test, about 20,000 tracers were added with the plant feed and subsequently recovered from the products with a dry low intensity magnetic separator. The Tromp curve determined by conventional heavy liquid analysis was displaced towards lower densities compared with that determined by tracers, indicating that the porous shale particles absorb heavy liquid. It is concluded that for porous materials like oil shale and coal, the tracer method gives the most accurate results. In pilot scale testwork the tracer method is also much faster than the conventional heavy liquid analysis, as rather large samples have to be processed by the latter method to ensure Representativeness.

Jan 1, 1987

By Baohm C, Barker T

There have been significant changes in the Australian mineral sands industry in recent years due to changing supply and demand conditions, new product opportunities and opportunities for rationalisation of operations. Earnings within the industry have typically been volatile and this has been reflected in the share prices of listed mineral sands companies. Apart from the effects of variations in the state of the economy on the industry, share prices have also reflected the extent to which a company's earnings volatility is due to capital structure, the relative proportion of fixed costs to total costs and the nature of th'- sales mechanism. At the time of writing, the high prevailing share prices for industry participants and the current outlook for the industry would suggest that the time is opportune for raising equity capital. The immediate outlook for the industry and its various product segments appears favourable but beyond this the usual uncertainties remain. The new tax environment will cause most companies in the industry to have to rethink their dividend and capital structure policies. Most shareholders will now be concerned to maximize dividend receipts and minimise exposure to capital gains tax. Companies in the industry that have relied fairly strongly on earnings retention to help finance growth in the past will- need to look to increased equity raisings in the Future.

Jan 1, 1986

IT will be noticed, from the following contributed papers on the various plant, what an infinite number of parts are required to be kept in active operation in order to derive a resultant product of commercial value from the ores and materials received at the works. Crude ores and concentrates, in every degree of complex structure and resistance to treatment, are arriving daily from near and distant places, moreover their metallic contents are so varied that an outsider, unacquainted with the operations, would naturally wonder how it is possible that the rare elements are to be sorted out and classified into their true order, to meet industrial requirements.The proposition is necessarily not a simple one and owners of mining properties have naturally refrained from smelting their complex ores on account of the technical difficulties of attaining high efficiency and recovery of the metals, where limitations are imposed in procuring a variation of ores that lead to the best smelting and refinmg result. This difficulty obviously imposes many disabilities on the smelter, who is prepared to accept all such complex ores, and it may be said that were therenot available a large weekly supply of lead concentrates from the company's own mine at Broken Hill, of standard quality, much of the material being treated in the world today would certainly not be marketable.In order to sustain full efficiency, each section of the works must maintain its.true balance and synchronize with the requirements of such other departments as are dependent on its partially treated materials. This harmony of operations is not only imperative as regards tonnage output, but also relies on the condition of the resultant treatment by each plant, no large variations being permissible.The various officers are, therefore, dependent on one another to keep the order of the operations flowing regularly. This is accomplished by constant intercommunication and observation, as...

Jan 1, 1918

By R Lastra

Applied mineralogy involves conducting investigations on ores, minerals and materials to solve problems encountered in mining, metallurgy, processing, industrial minerals, environment, health and other fields. The investigations are performed to determine the mineral behaviours during processing by using every mineral and ore characterisation technique and appropriate instruments. As the field is young, new techniques and instruments are still being developed. This paper attempts to convey the scope of the field by:describing the capabilities of the respective research instruments for determining mineral characteristics, summarising investigations of gold as an example of applied mineralogy studies of precious metals, andpresenting a case history where applied mineralogists worked closely with mineral processing engineers on a base metal ore and mill products to help the engineers optimise their processes for maximum recoveries.

Jan 1, 2008

By Howell M. W

The purpose of this paper is to outline the main points in the construction of the various types of wire ropes more commonly used for winding in Australia; and the maintenance of the ropes, and cage and skip safety gear as practised at the South mine, Broken Hill.It should be mentioned that both of the shafts at present in use are dry, and both downcast with or without the assistance of the two exhaust fans normally in use: Night shift and week.-end overtime are practicaly non-existent.Thus, during night shift, the cages in No. 7 shaft are landed on the chairs at the surface, providing efficient covers for the· shaft, and allowing the maximum amount of rope to be wound on to the drums. This also applies to the cages of both No. 7 and No. 4 shafts during the week-ends.These factors, combined with electric winding and skip haulage, are calculated to obtain the best use of the ropes when properly attended.WINDING ROPES-TYPE AND CONSTRUCTIONThese ropes may be divided into four main types which will include the more commonly used constructions(a) One-size strand.(b) Warrington strand.(c) Flattened strand.(d) Locked coil.1. One-size strand as the name implies, is a rope the strands of which are constructed 9f wire of the one size.Usually the strands are of 7, 19 or 37 wires.

Jan 1, 1940

By L Reynolds, N Whetter, S C. Cox

The Reefton Goldfield has had the largest hard-rock gold production (64 t Au) on the West Coast of the South Island of New Zealand, and is currently under renewed development by Oceana Gold. The gold predominantly occurs in variably sheared quartz veins that are associated with zones of tighter, shorter wavelength folds in the host Greenland Group metasediments. The quartz veins typically occur as a series of plunging shoots that align with specific fold limbs or fold hinge zones. Shear zones containing disseminated mineralisation and quartz veins have thickness variations that relate to the angular relationship between the shear and host-rock bedding. Exploration strategies and targeting can be developed around both types of structural control.

Jan 1, 2005