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By L Faulkner

The Tarnagulla Gold Project in Central Victoria, Australia, was developed and operated by Reef Mining NL between 1994 and early 2000, producing 53 000 ounces of gold from the Nick OÆTime Shoot, a single narrow vein shoot structure within part of the larger Poverty Reef, with a strike length ranging from 30 m to 60 m. The ore shoot was developed over a vertical interval of 190 m, using a small cross-section decline and small, mechanised equipment. Various stoping methods were employed including mechanised cut-and-fill with a single boom jumbo, hand-held mining using airleg drills and rope scrapers, and small uphole retreat stopes using a line of sight remote operated LHD to recover a crown pillar. Experience during stoping showed that airleg drilling and rope scrapers gave much better dilution control than diesel equipment. Innovations included a low-cost hydraulic fill system. Due to the small scale of the deposit, the feasibility studies, planning and permitting for the mine were based on very limited drilling information; however, the mine was brought into production within two years of the discovery. While the mine made an operating profit, it failed to fully repay capital at the low gold price then prevailing. Applying the lessons learned from the operation to optimise the access and stoping method, the project is re-examined at todayÆs gold price and operating costs. Central Victoria has the potential to host many similar small deposits. The authors were respectively Non-Executive Director and Resident Manager for Reef Mining NL when the mine was operating.

Jan 1, 2008

Tholeiitic metabasalts comprise at least five geochemically distinct mafic volcanic associations of Late Palaeozoic age within the Gympie Province, southeast Queensland. Geochemical features indicate that parental magmas of the various metavolcanic suites were generated in contrasting tectonic regimes, although each of the suites shows some affinities with eruptives from convergent plate margin settings.Basalts from the Highbury Volcanics of the Gympie Group are island arc tholeiites (IAT) formed during an immature stage of eruptive activity in an intra-oceanic arc. They are unique among the analysed metabasites in possessing high Zr/Nb (Zr/Nb - 30) and very high Ba/Nb, and as well as low Ti/V, Ti/Zr and Ti/Y. These features are explicable solely in terms of contributions from a depleted, convecting upper mantle source, and large ion lithophile element (LILE) enriched fluids ascending from subducted oceanic crust.

Jan 1, 1990

A thick sequence of alkaline intrusions and volcanic rocks underlies a Quaternary caldera on Liliir Island. The sequence is host to a still active sub-aerial hydrothermal system and associated epithermal gold mineralisation. Sub-horizontal alteration horizons exhibit progressively increasing chondrite norma-lised (La/Lu) en and (La/Sm) cn ratios from unaltered shoshonites, to the potassic alteration zone, to the argillic altera-tion zone to the advanced argillic alte-ration zone. The increasing fractionation of HEE, and especially of LHEE, up the alteration sequence is the result of de-creasing pH, temperature and alkalinity of the hydrothermal fluids with increa-sing alteration intensity. HRE3 were especially mobile in argillic and advanced argillic alteration units characterised by acid fluid conditions and large fluid volumes. Abundant Cl, S and CO2 within the hydrothermal fluids and thus abundant REE complexing agents and large fluid volumes favoured the mobility of REE during hydro-thermal alteration of the volcanic rocks and intrusions. Steam escape, mixing of the gases with groundwater and a change from a magmatic neutral chloride hydro-thermal system to a meteoric acid sulphate system was accompanied by liquid/vapour ratio changes, pronounced alkalinity, pH and temperature decreases, and fluid/rock ratio increases. This caused the mobili-sation, fractionation and deposition of PF.F.

Jan 1, 1990

By Kneisley RO

This paper presents a brief overview of current bump mechanics theories and pillar design methodologies, and relates these concepts to experiences at two mines located in a north- central Utah coalfield where different pillar designs were used to control mountain bumps. Experiences gained at the first mine demonstrated the successful implementation of a two-entry, 9.8 m (32 ft)-wide, yield-pillar design. A U.S. Bureau of Mines field study quantified the timing of chain pillar yielding and resulting load transfer from the gateroad. In-mine pillar response, although apparently sensitive to site-specific conditions, compared favorably to estimates derived using two yield- pillar design methods. A second study conducted at another mine located in the same district, but subjected to different geologic conditions, documents the unsuccessful attempts to employ progressively narrower three-entry pillar designs based on successes achieved at the first mine site. This second mine never achieved a true yield-pillar design. Use of pillar widths ranging between 9.1 m (30 ft) and 27.4 m (90 ft) always resulted in violent bumps in the tailgate pillars. The pillars were either too large to yield, or too small to support peak operational loads. Hypothetical gateroad systems were evaluated using both analytical and empirical approaches for configurations comprised of two rows of conventional pillars, and systems incorporating both yield and abutment pillars. Analysis concluded that yield pillars less than 6.1 m (20 ft) wide and abutment pillars ranging between 30.5 m (100 ft) and 39.6 m (130 ft) square would be required to achieve a stable gateroad design. However, results of a field study conducted on a two-entry, 36.6 m (120 ft)- wide abutment pillar concluded that abutment pressures from the first panel overrode the pillar, and that a still larger pillar may be required to preclude bumps in the tailgate during second panel mining. Without the benefit of a demonstrated in-mine success, it is not clear which design would ensure elimination of gateroad bumps.

Jan 1, 1992

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 A Dix

Fire suppression systems are but one of the many technologies currently available to manage operational tunnel risks. However, the actual reasons for their use are often shrouded in mischievous discussions of the marketing variety.The international tunnelling community still stands divided on the merits (or otherwise) of fire suppression systems. For some the debate focuses on their cost compared to the theoretical benefits they bring to human safety.Long standing concerns about their potential adverse effects in an emergency are often at odds with the experience from tunnels which use them. High installation and operational costs are cited as reasons not to use them, yet toll road operators and insurers increasingly use them as a risk mitigation strategy for toll revenue protection.Fact or fiction, myth or reality, should such systems be seriously entertained or are they just another expensive gadget in the escalating array of expensive toys for modern tunnels? Ultimately this presentation argues that they have their place as a risk mitigation measure to achieve a range of objectives. The exact circumstances for their use ultimately fashioning their design and operational characteristics. This is an abstract only. No paper was prepared for this abstract.

Mar 8, 2011

By Tucker G, Clark A, Young M. F, Johnston M

Mount Isa Mines has made a huge commitment to process control in milling. Yet in lead zinc we still failed to achieve a steady operation. Comparisons with manufacturing plants showed the key difference was failure to control plant inputs. Lead

Jan 1, 1998

One of primary causes of poor blast performance is the improper relief of explosive energy. Under or over-confined blasts modify the explosiveÆs path of least resistance, which changes where and when the explosive energy is applied resulting in less than optimum blast performance. During the research for this paper the overbreak characteristics of five full-scale blasts were quantified using high speed cinematography and borehole cameras. The effectiveness of various overbreak control methods was also evaluated to guide design refinement. The results of this research along with general recommendations for reducing excessive damage are included with this paper.

Jan 1, 1999

In the general planning of this area, provision was made for the distribution over the whole area as required of the following services:(a) Power and lighting from the substation distribution boards 'located in the winder house.(b) Miscellaneous electrical indicating, control and signalling systems.(c) Telephone lines from the main internal automatic exchange located in the changehouse, the town exchange to the automatic exchange and also direct lines from the town exchange to selected offices.(d) Compressed air from the incoming 16-in. air main. (e) Water, both unfiltered and filtered; and the disposal of the following effluents:(f) Sewage from the area to the town sewage system.(g) Changehouse shower water to the regeneration area.(h) Storm water to the general mine surface drainage system leading out to the naturally drained area north of the No. 8 Shaft.

Jan 1, 1957

By Hinchliffe WD, Griffin A

The desorption of gold from activated carbon is promoted by adding organic solvents to aqueous cyanide solutions. At 65-80¦ the elution of gold is fast and is not affected by water quality. The Micron Procedure involves pretreatment of the loaded carbon with NaCN/NaOH followed by elution with methanol vapour and condensate. Carbon is packed into a column above the distillation pot and acts as a fractionating column. Recovery of the methanol condensate leaves a methanol free concentrated gold solution and carbon containing

Jan 1, 1984

By V P. Beskrovnaya

Tests for the development of a metals recovery technology from samples of a Russian gold-bismuth deposit were carried out. Gold, silver and bismuth assay reported 5.6 g/t, 3.0 g/t and 0.08 per cent, respectively. Two flow sheet options were pilot plant tested: gravity/cyanidation of gravity tailings with subsequent flotation of cyanidation/carbon-in-pulp (CIP) tailings, and gravity/flotation concentration with cyanidation/CIP of concentrates. Option 1 results showed lower gold, silver and bismuth recoveries (81.3 per cent Au, 55 per cent Ag and 74.0 per cent Bi) due to low flotation efficiency for cyanidation tailings. Therefore, a flow sheet involving gravity/flotation concentration to produce bismuth-gold concentrates (0.8 per cent Bi) with subsequent cyanidation/CIP was recommended. Gold, silver and bismuth recoveries obtained by this method to the combined gravity/flotation concentrate were 90.2 per cent Au, 83.3 per cent Ag and 80.2 per cent Bi of the ore, respectively. Overall gold, silver and bismuth recoveries were 83.0 per cent Au, 40.5 per cent Ag and 80.2 per cent Bi, respectively. Gold and silver recoveries to the cathode precipitate were 92 per cent Au and 48.6 per cent Ag (per operation). Reagents consumed for flotation were 0.1 kg lead acetate/t ore, 0.4 kg butyl xanthate/t ore, 0.2 kg T-80 frother/t ore, 0.02 kg sodium hexametaphosphate/t ore, 0.15 kg copper sulfate/t ore. Reagents consumption for cyanidation was 0.42 - 0.48 kg NaCN/t ore and 0.2 kg CaO/t ore. It was recommended to deliver bismuth concentrates after hydrometallurgical treatment to a smelter. Overall bismuth recovery including bismuth recovery achieved by pyrometallurgy was 60.0 per cent. However, it was obvious that delivery of bismuth concentrates to a smelter and their commercial treatment would be very expensive due to relatively high mass pull of bismuth concentrates (7.6 per cent of the ore weight). For this reason, thiourea leaching and hydrochloric acid leaching with subsequent cyanidation/CIP were investigated as alternatives to cyanide leaching. These two alternatives were proposed to enable optimal recovery of valuable metals from concentrates on-site. Recoveries obtained by thiourea leaching were 91.2 per cent Au, 90.5 - 91.9 per cent Bi and 77.0 - 78.1 per cent Ag. However, that method required considerable capital and operating costs. As an alternative, hydrochloric acid leaching with subsequent cyanidation was investigated. Test results showed improved gold, bismuth and silver recoveries, which were 94 - 95.9 Au per cent, 94 - 96 Bi per cent and 76 - 78 Ag per cent, respectively. Hydrochloric acid consumption was 100 kg/t concentrate or 7.6 kg/t ore. Current efficiency during electrowinning was about eight to 12 per cent. A recommended flow sheet involving hydrochloric acid leaching of concentrates, electrowinning of bismuth from solutions, recycling solutions after electrowinning and cyanidation of hydrochloric acid leaching cakes is described. Overall recoveries achieved by the proposed flow sheet were as follows: 84.8 - 86.5 Au per cent, 75.8 - 76.9 Bi per cent and 63.2 - 64.9 Ag per cent. Based on results from these tests, initial data for a bankable feasibility study and plant designing were developed.

Jan 1, 2007

By Kolarczyk M

When controlling the ventilation process in a deep mine some knowledge of the sensitivity of the air volume output to changes in the resistances of network side branches is of great advantage.Sensitivity is taken to mean the limit of the differential quotient AV /ART where AV. is the change in air output in the i--h side branch caused by a change of resistance LI R in the r-th side branch. A method Is presen- ted for determining any arbitrary co- lumn of the sensitivity matrix. A network interpretation of this met- hod was developed in which an ancilla- ry network additional the basic network is constructed and solved, giving an analysis of the sensitivity signs de- pending on the structure of the network.

Jan 1, 1988

The laboratory-scale reduction of fixed beds of iron ore pellets has been investigated over a range of experimental conditions. The effects of reduction temperatures, gas compos- itions and flowrates on 1) the rate of reduction and 2) the physical properties of the metallized products after reduction are being studied as part of a general programme aimed at the evaluation of the use of gaseous reductants for the direct reduction of Australian iron ores. This paper deals primar- ily with the effects of temperature on the rate of reduction using a H2/CO gas mixture. The physical properties of the metallized products such as strength after reduction, abrasion resistance and porosity are presented as functions of the reducing temperature.

Jan 1, 1974

By Komosa T

The increase in the proportion of sulphide ore treated by the gold mining industry has led to generally higher oxygen requirements. Additions of pure oxygen, hydrogen peroxide and in some cases calcium peroxide, have been proposed as a means of satisfying the oxygen demand and overcoming the problems from reactive sulphides in the ore. Current oxidant addition options and practice are reviewed.Laboratory oxygen demand tests are reported for a suite of ores to show some of the effects of pH and preaeration.Laboratory leach tests at high and low dissolved oxygen levels are reported on two of the ores with higher oxygen demands, and the results are assessed in terms of gold leaching kinetics, ultimate gold extraction, and cyanide requirements.

Jan 1, 1992

By Hammett PHJ

Oil Exploration Companies are primarily interested in how much oil or gas is present in the rocks in an area in which an exploratory well is drilled. The solution of this problem requires a combined effort on the part of the petroleum geologists, drilling engineers, logging and drilling contractors. To help in'explaining how the drilling and evaluation is earried out the paper has been divided into two sertions, one titled Drilling which is presented by Mr. P.H.J.-Hammett and the seeond titled Evaluation which is presented by Mr. R.M.L. Elliott. A typical Perth Basin Well has been chosen as art example for this presentation. In Figure 1A is shown the type of sandstone and shale sequence encountered in this area.

Jan 1, 1964

By P N. Duan, Z G. Liu, M S. Chu, X X. Xue, B Liu, G J. Cheng, T Jiang, J X. Liu

High-chromium vanadium-titanium magnetite has not been exploited and made full use of on a large scale so far due to the immature utilisation technology and the reality that the utilisation efficiency of valuable metals still urgently needs to be improved. In the present paper, the isothermal reduction kinetics and mechanism of high-chromium vanadium-titanium pellets were studied at 800–1100°C. The mineral composition transformation of pellets before and after reduction was analysed by means of X-ray diffraction (XRD), and the microstructures were examined by scanning electron microscope (SEM) equipped with energy dispersive X-ray (EDX) to reveal the elemental distributions. The effect of reduction temperature on the volumetric swelling degree and cold crushing strength was also studied. It was found that reduction temperature has a large effect on the reduction rate of pellets, and the increase in reduction rate is more obvious in the range 1000–1100°C than 800–1000°C. The volumetric swelling degree of pellets increased with increasing reduction temperature, while the cold crushing strength decreased. The transformation of mineral species can be expressed as Fe2O3 ? Fe3O4 ? FeO ? Fe, Fe2O3·3TiO2 ? Fe3O4· (2FeO·TiO2 ) ? 2FeO· TiO2 ? FeO·TiO2, (Fe0.6Cr0.4)2O3 ? FeO· Cr2O3 ? Cr2O3 , and Fe2O3· VO/V2O3 ? VO. The apparent activation energy of the reduction reaction was calculated to be 44.3 kJ/mol, and the reduction rate is controlled by the combined effect of interfacial chemical reaction and gas diffusion through the porous product layer. The rate controlling steps were further studied by calculating the resistance percentages. The interfacial chemical reaction was found to be predominant in the initial reduction stage, with the percentage effect of gas diffusion through the porous product layer gradually increasing during reduction.CITATION:Cheng, G J, Xue, X X, Liu, J X, Liu, Z G, Chu, M S, Jiang, T, Liu, B and Duan, P N, 2015. Reduction kinetics and mechanism of pellets prepared from high-chromium vanadium-titanium magnetite concentrate, in Proceedings Iron Ore 2015, pp 349–358 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Skinner A. J, Thoman B. C

The general structure of microprocessors and their method of use is described, and de- tails given of their application in two parti- cular examples of instrumentation for mineral concentrators. One is in a pulp density gauge, and using this example, the way in which a microprocessor-based unit can be made to be self-calibrating is described. The other is in an on-stream analysis detector for uranium in solvent, where a microprocessor is used to re- place a mini-computer.

Jan 1, 1977

Syferfontein Colliery, part of the Sasol group of companies which specialises in the field of petro-chemical production, was established in 1990. The mine is situated about 150 km east of Johannesburg, South Africa. Two coal seams are mined, utilising two 75 m3 draglines, shovels and a fleet of 177 ton rear dump trucks. The mine will reach its full production capacity of seven million tonnes per annum in 1992. During the planning period, prior to the establishment of the mine, management were confronted with the unstable socio-political environment in South Africa which could jeopardise the eventual success of the mine. They consequently conducted a strategic planning exercise to determine guidelines for mine planning to improve the chances of success in this unstable third world environment.The strategic guidelines formed the basis for specific actions taken during the planning and commissioning of the mine. Specific actions were taken in the field of operating cost, labour relations, working environment, logistics and the general environment. First results indicate that these actions have played a major role in the success of the mine to-date. This process can be utilised by others facing similar or even totally different uncertainties.

Jan 1, 1992

By D S. Scovira

The effect of blast vibration on highwall stability is a common concern for many open pit mines. Vibration in such a case is a typical near-field blast vibration situation. Vibration modelling in the near-field of a blast requires consideration of both the amplitude and frequency attenuation of waveforms with distance. Most existing blast vibration models are designed for far-field vibration and do not simulate the frequency attenuation and its effect on waveform shape. With the advent of electronic detonators it is desirable to quantify the effects of blast delay on the amplitude as well as the frequency of blast vibrations. A suitable modelling tool is proposed here. At present, a blast vibration model with double attenuations(amplitude and frequency) has been developed at Orica. The present model simulates the amplitude and frequency attenuations separately using different transfer functions. The amplitude attenuation is modelled according to the non-linear relation between the peak particle velocity (PPV) and the charge weight scaled distance established from the signature hole vibration. The frequency attenuation is modelled with the signal broadening based on KjartanssonÆs transfer function û a linear model for attenuation of waves. The model is capable of taking multiple sets of signature waveforms as input to improve the modelling accuracy of the wave propagation in the geology at a site. The screening effect of the earlier firing holes in the path of a later firing hole is taken into account on not only the amplitude, but also frequency attenuation. The present blast vibration model is suitable for modelling both near-field and far-field blast vibrations. It yields reasonable agreement with measured field data for the near-field vibration examples discussed.

Jan 1, 2007

By M Chappell

This paper describes the design of the steel fibre reinforced precast concrete (SFRC) segmental lining for the intake and discharge tunnels for the Gold Coast desalination plant in Queensland. In addition, the key design requirements and design methods for the lining of these 2 km long, 2.8 m internal diameter tunnels, including structural, durability and maintenance requirements are discussed. Details of the segment configuration and erection process are presented along with information on the manufacture and trial testing of the concrete for the segments. The paper also gives a brief introduction to steel fibre reinforced concrete behaviour. Construction of the tunnels commenced in April 2007, and the authors believe this is the first application of this technology in Australia.

Jan 1, 2008