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By Ramsay WRH, Morand V

Structural, mineralogical, and textural data from the Tarnagulla Goldfield demonstrate that the area has undergone three significant phases of deformation. The first phase of deformation (Dl) predates the intrusion of the Tarnagulla pluton, which has been dated using K/Ar as 391 ¦ 5MY. We regard this pre-granite deformational event as the major regional deformation. Gold-bearing quartz veins have been deposited in dilational sites on west-dipping reverse faults. These sites demonstrate a geometry related both to faulting associated with Dl and the plunge of the Fl fold axes. This evidence, together with chronology of unmineralised ? D2 and D3 faults, the absence of quartz veining associated with D3 events, and the deformation of carbonate-quartz-biotite-sulphide aggregates within Sl by later S2, lead us to conclude that the bulk of the mineralisation was essentially syn- or late Dl. S'80 values for fluids in equilibrium with vein quartz from Central Victoria have indicated equivocal support for either a magmatic or metamorphic origin. Our evidence supports a pre-magmatic origin for mineralisation at Tarnagulla and hence tends to favour a metamorphic fluid source.

Jan 1, 1995

This paper talks about the experiences of groups we have worked with over the last few years in the Asia-Pacific region (Australia, Canada, New Zealand and Papua New Guinea) and the ways that they have worked to bridge the divide between traditional and introduced structures, governance at a regional level and the introduction of traditional values into monitoring and evaluation practices. In doing this these groups have created structures and processes which have helped them engage both more effectively with external stakeholders while maintaining the legitimacy of their own operations with their own constituents. These are important ideas for those involved in the mining industry that could provide a number of very tangible benefits to mining firms and their engagement with these kinds of groups.

Jan 1, 2009

By X Hill

Throughout the 2016/2017 financial year, the NSW Resources Regulator conducted an assessment of each underground metalliferous operation across the state to assess how each operation managed the principal mining hazard of ground and strata control. The assessment considered all aspects of the mining process, including all aspects of managing geotechnical risk within drawpoints. This assessment is ongoing and, therefore, this paper is limited to the first six mines assessed in the program.In 2015 there were three fatalities in and around underground drawpoints in Australian metalliferous mines. Whilst many of the systems of work around underground development are consistent across the industry, there are large discrepancies around how each underground mining operation manage the risks associated with drawpoints.For drawpoints to be effectively managed, their management needs to be considered at the earliest stages of the mine planning process. By using downholes and adopting remote systems of work – systems that are continuing to improve with technology – the risks drawpoints posed can be greatly reduced.The assessment by the NSW Resources Regulator revealed a number of common failings across the state in the management of the risks that drawpoints pose. The assessment also observed a number of innovative practices that particular operations have adopted in the wake of serious incidents occurring within drawpoints at their operation; however, these practices have not been communicated to other operations.It is hoped the learnings from the assessment can be considered by industry and reduce the risks drawpoints pose in underground metalliferous mines.CITATION:Hill, X, 2017. Learnings from review of drawpoint management across New South Wales mines, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 143–150 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

When the new No. 3 Shaft is in full operation, the main hoisting duties will be in connection with the raising of: (a) ore from the various mining operations, and (b) mullock, or broken country rock, from development work in extending access to existing levels, opening up new levels, exploratory work, or sinking the shaft to greater depths.

Jan 1, 1957

By T Roberts, D Faulkner, G Watt

Traditional mechanised resin rock bolting in hard rock underground mines requires the installation of resin capsules into a pre-drilled hole prior to the rock bolt being spun into a hole to mix the resin and set the bolt in place. In poor rockmass conditions, especially at depth or in highly altered faults and shears, the condition of the holes often deteriorates as the poor ground around it unravels and falls into the hole. This results in partially or fully blocked holes that either damages the resin capsule when they are being inserted into the holes or prevent it entirely until the hole is continuously cleaned of debris. This deterioration of the hole condition, and continuous need to clean and re-drill holes, also increases the diameter of the hole which in turn affects the continuously mechanically coupled anchorage mechanism of the rock bolt to the rockmass as there is simply not enough resin in the hole to fill the annulus between the bolt and the rock. This results in a large increase to critical heading cycle time and, more importantly, results in the rock reinforcement not performing as per design specification and increases the risk of instability. To overcome the quality control issues with resin bolt installation in poor ground, a single pass drill, install, inject and tension self-drilling resin bolt application was designed and implemented for use in such conditions. This system allows the operator to inject a two part polyester resin through a self-drilled hollow bolt to mix and fully encapsulate the rock reinforcement. The self-drilling bolt allows for post injection of the hole after the bolt has been installed into the rock and gives the operator manual or automated control on the amount of resin used in the hole to ensure complete encapsulation and continuously mechanically coupled anchorage to the rock. This allows the reinforcement to work as designed and provide the Geotechnical Engineer extra quality control confidence in these conditions. The implementation of this single pass resin bolting system resulted in significant decreases to the resin bolting cycle time and rock bolt quality control failures. In this paper the design, implementation and embedment into the development cycle will be discussed and the in situ quality control checks used to validate the increase in rock bolt installation quality will be shared. CITATION:Watt, G, Roberts, T and Faulkner, D, 2018. Single pass drill, install and inject self-drilling resin bolt application in poor ground, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 323–343 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

Driefontein Gold Mine together with Kloof Gold Mine and Beatrix Gold Mine forms part of Gold Fields South Africa. Driefontein Gold Mine is situated near the town of Carletonville, 50 km south of Johannesburg, in the Gauteng Province. The 4 Shaft East complex comprises of the 4 Main Shaft and the 4 Subvertical Shaft. The main shaft is 9150 m in diameter and was sunk in 1984 to a depth of 2000.5 m. The 4 Subvertical Shaft is 7320 m in diameter and was sunk during 1985 to a depth of 3006 m. Full production was, however, only reached during 1988. Intensive mining is currently being done between levels 28 to 42. In 2002 a decision was made to start mining the shaft pillar, situated between 32 and 33 level in the subvertical shaft. Intensive studies showed that with selective mining scheduling the total mineÆs life could be lengthened by nine years if accessed timeously. The higher grades present in the shaft pillar can be mixed with lower grades from the same reef band presently mined 1500 to 2000 m away from the subshaft pillar area. The shaft pillar comprises 50 per cent of the remaining ore resources available. However, no provisions were made in the initial phases of the shaft development to extract the shaft pillar. Grades between 4300 cmgt to 2500 cmgt relating to 23 and 14 g/t are present in the shaft pillar and an estimated 50 tonnes of gold can be produced from this pillar in the period from 2007 to 2015. The pillar extraction is the key to DriefonteinÆs long-term gold profile. Every geological feature possible is represented in this to-be-mined pillar area. The pillar around the shaft is a complex structure featuring hard and soft lava, sedimentary structures/plane parting that moves against each other, quartzite capping, etc. Replacement of services and secondary support systems were designed, modelled and put in place. The original steelwork was not designed to cope with the various stresses and movements, which are expected once the extraction process is started. Existing shaft steelwork was used as far as practically possible. The principal behind the design was that the steelwork would be totally disconnected from the shaft lining over its total length of 132 m in the area of the reef intersection. This will allow the steelwork to move independently from the geological structures surrounding it, allowing a certain degree of distortion of the shaft lining, moderate twist and tilt to take place without interfering with hoisting operations.

Jan 1, 2005

By Langberg D, Gray N. B

The flocculation of hydrophobic magnetite with gold was examined as a possible means of recovering fine (95 per cent were possible for 1.5 - 3.0 ¦m and 5.5 - 7.5 pm gold sizes. The effect of process variables on the flocculation process was explained by variations in the adhesive force between the gold and magnetite.

Jan 1, 1991

By Zhijing Z, Huiling Z

The influences on flotabilities of dolomite and magnesite with modifiers and influences on the function of collectors and modifiers with Mg+z Ca+2 were studied. The flotation results of artificial mixed mineral showed that using combined salified water glass and (NaPO3)6 as a modifier for magnesite-dolomite separation can obtain an excellent Selectivity.

Jan 1, 1993

By A Fareth

Constructed between 1885 and 1891, the New Croton Aqueduct (NCA) in New York State is a 50 km long (31 mi) brick-lined tunnel conveying water from the Croton watershed north of New York City to distribution systems in the Bronx and Manhattan. Except at two siphons, the aqueduct operates as an open channel conduit from the New Croton Reservoir downstream 39 km (25 mi) to the Jerome Park Reservoir in the Bronx. The remaining 11 km (6 mi) is operated as a pressurised conduit and includes a major siphon, of circular cross-section, under the Harlem River. The aqueduct has a flow capacity of approximately 1100 million litres of water per day (13 m3/s or 290 million gallons per day) and supplies on average ten per cent of New York CityÆs drinking water. The CityÆs water supply system is operated and maintained by the New York City Department of Environmental Protection (NYCDEP). This paper covers the work done during the three main stages of the program to rehabilitate the entire NCA: inspections, design and rehabilitation. It also includes some of the more interesting structural findings of the original construction as well as documents and drawings from the NYCDEP archives. The rehabilitation program has been underway in phases since 1993, with inspections scheduled to minimise outages, allowing this strategic aqueduct to remain in service during critical seasonal periods. The open channel flow section of the aqueduct in the north is horseshoe shaped, with inside dimensions of 4.1 m (13.6 ft) in width and 4 m (13.5 ft) in height. The pressurised section is 3.7 m (12.3 ft) in diameter, and includes a 90 m (330 ft) deep siphon under the Harlem River. A total of 163 million bricks were used in the construction, enough to build a 48 km (30 mi) wall around Manhattan Island, 3 m (10 ft) thick and 15 m (50 ft) high.Between 1993 and 1997 a series of in-tunnel investigations were performed in the open channel portion of the NCA, consisting of field inspection, non-destructive geophysical testing, and coring of the brick liner. Between November 2004 and September 2005, a major inspection program was conducted to assess the condition of the 11 km (6 mi) long pressurised section and all shafts, headhouses and blow-off structures along the entire 50 km (31 mi) alignment. Inspection methods included using an underwater remote operated vehicle (ROV) equipped with sonar and cameras to inspect the deep siphon, fibre optics examinations of probe holes drilled through and beyond the brick lining, and core holes and geophysical inspections to assess properties of the liner and behind-the-liner materials. A water pressure and test grouting program was conducted to assess methods and expected grout takes for the rehabilitation work in the pressurised sections. The rehabilitation program is anticipated to be completed in 2010.

Jan 1, 2008

The basic model for the evaluation of any coal-bearing property is the cash flow projection, the major components of which are operating costs, capital charges, taxation and revenue. A range of cash flow projections can be produced by varying the assumptions which underlie the operating costs, by assuming various forms of capital funding, by making assumptions as to future taxation and by speculating upon the present and future market value of the product. As for any model, the informational inputs and assumptions are vital because, no matter how sophisticated the processing, the informational inputs and assumptions cannot be improved by it. That is to say, the validity of the output (the total evaluation itself) cannot be of greater certainty or significance than that of the inputs. The total evaluation can of course be expressed in a number of ways such as the Discounted Cash Flow (D.C.F.) Rate of Return, the Net Present Value or, the Payback Period. The foregoing statement may seem trite. However, it is necessary to be clear about it so as to avoid unnecessary complication and a preoccupation with techniques as opposed to the informational inputs and assumptions. So far as techniques are concerned, much has been written and said about them during the last decade. Most of us have heard, if not always understood, something about probabilistic models, Monte Carlo simulation, sensitivity and risk analysis to say nothing of inflationary costing and the relative merits of developing cash flows in terms of current or constant money. Those techniques have their value, particularly if they can serve to illuminate conclusions which could not be reached on a simple and even perhaps on an intuitive basis. I am, however, reminded of one major coal mining project in which 20 or more major variables were identified, many cash flow projections were run on the computer and a detailed sensitivity analysis was carried out. The major conclusion reached was that the D.C.F. Rate of Return was predominantly sensitive to variations in selling price and operating cost. Of course, the funding and fiscal elements of a cash flow projection have to be dealt with as rigorously as possible. However, in the development of any coal property, capital requirements and taxation are, in part at any rate, dependent upon the assumed operational parameters. If the latter are misjudged, the whole evaluation process is deeply affected. The same is true of revenue, in the sense that, the positive cash flow is a function of output as well as selling price and again, misjudgements about achievable and maintainable levels of production also deeply affect the final evaluation. I shall try to underline the fundamental influence of the technological factors upon lead times, capital costs, operating costs, taxation, funding and the achievable and maintainable levels of production. In turn, these affect the whole question of coal property evaluation and indeed, the likely success or failure of any coal mining venture. I make no apology therefore that this paper does not set out to discuss the more esoteric aspects of the evaluation process but rather, directs attention towards some of the informational inputs and assumptions which merit clarification and discussion.

Jan 1, 1975

By C Ward, U Mueller

Compositional geostatistics is an approach developed to ensure that the constant sum constraint induced by geochemical iron ore analysis is respected in estimation and simulation. Jack-knifing and cross-validation were used within this framework to compare the results from ordinary cokriging of the additive log ratio (alr) variables with those from conventional ordinary cokriging. Two methods were used to back-transform the alr estimates: the crude additive generalised logistic back transformation and numerical integration via Gauss-Hermite quadrature. Previous work on a blasthole data set from a Yilgarn iron ore mine showed promising results, with the Gauss-Hermite quadrature method returning results comparable to ordinary cokriging from the point of view of bias, but superior in that the constant sum constraint imposed by geochemistry of the data was honoured. Other practitioners have noted that the linear interpolation of non-linear log ratio transformations will result in biased results, and that this bias can be masked in a (grade control) setting where the spatial density is high. To test this assertion, the methodology has been extended to successively lower spatial density data sets. The results and applicability to routine iron estimation are discussed.CITATION:Ward, C and Mueller, U, 2013. Compositions, log ratios and bias - from grade control to resource definition, in Proceedings Iron Ore 2013 , pp 313-320 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By Creasey JW, Rixon KL

Underground mining in the Bowen Seam has shown that the majority of outbursts have co- incided with faults, igneous dykes and sills, stone roof rolls or some combination of these. The coal measures are deformed principally by N- S trending, easterly dipping thrusts presumed to he associated with the major, reverse Collins- ville Fault. The old Collinsville State Mine records suggest that thrusts and strike-slip faults have been common sites of outbursts. In contrast, normal faults have not been outburst- prone. Detailed geological mapping in Bowen No. 2 Colliery 53 east and west panels has been carried out in the hanging wall of a thrust zone of 6.1 m throw. The associated sheared coal has been defined and several fracture sets delin- eated. Sheared coal can be observed up to 170 m from this thrust zone, but this is dependent on the vitrinite content of the upper seam section worked. Fvidence indicates that outbursts have crnrroJ only in extremely sheared coal. Curious spherical- to cylindrical-shaped c,,.31 ohjects ("apples" and "rods") are related to the deformation in the vicinity of the thrust zone. The frequency of rods rises from 0 at 31)0 m, to I per metre at 150 m, and to 2.5-8.5 per metro at 10 m from the -

Jan 1, 1980

The Drake-Rivertree area lies in the far north east of the New England district of New South Wales. Drake is some 500 miles north of Sydney by road and 36 miles west of Lismore. Rivertree is situated 24 miles north of Drake.The Drake deposits were first worked in 1878 for gold which occurred in a very fine state in ferruginous gossan but at depth copper ore became more significant. The lodes at Rivertree, discovered in 1887, were worked for silver but mixed sulphides became more prominent in deeper levels.Several mines operated at each centre and each locality smelted its own ore.The mines at both centres were operated sporadically for many years though production was not particularly substantial.A number of the larger mining companies have shown a recent interest in this mining field with special emphasis on the Drake locality.GENERAL GEOLOGYThe two mining centres are situated to the north and south respectively of a belt of Permian marine sediments and volcanics similar to, and probably representing an easterly extension of, the rocks of the Emmaville district further west.E. C. Andrews (1907) recognized two stratigraphic units within what he called the Drake Series. The Lower Division consists of rhyolite flows, tuft's, breccias and agglomerates, followed by trachytic and andesitic tuft's containing cladochonns, thanmopora willcinsoni and other Permian forms.

Jan 1, 1962

By Holcombe R. J, Dobos S. K, Little T. R

Blue amphibole-bearing rocks in the North D'aguilar Block of southeast Queensland occur either as relict pods and lenses within regionally extensive greenschist facies phyllites and schists or as blocks entrained in serpentinite-matrix melange. Epidote + crossite-bearing varieties predominate and formed under conditions consistent with underplating and high P:T metamorphism in a subduction-related tectonic environment. Neither lawsonite nor jadeite has been observed and metamorphic conditions are estimated at 380-4500C for pressures of 0.5-0.8 GPa. High P:T metamorphism occurred during the earliest stages of deformation and was superimposed upon protoliths of inferred Late Devonian - Early Carboniferous age, including mafic volcanics, tuffs and coarse volcaniclastic breccias as well as pelagic and henipelagic sediments, all of which have undergone varying degrees of over-printing to the greenschist facies. Greenschist facies metamorphism occurred during the second phase of deformation and was associated with the formation of mainly flat-lying or subhorizontal structures; it followed the cessation of subduction and occurred in response to either thermal relaxation during uplift or the imposition of regional heating induced by crustal thickening and/or synkinanatic granite emplacement. Uplift and cooling of the high P:T rocks was completed by 260-265 Ma and may have occurred in response to the same extensional processes which gave rise to the onset of rifting in the adjacent Esk Trough.

Jan 1, 1990

By C Mark

Coal bursts involve the sudden, violent ejection of coal or rock into the mine workings. They are a particular hazard because they typically occur without warning. During the past two years, three US coal miners were killed in two coal bursts, following a six-year period during which there were zero burst fatalities.This paper puts the US experience in the context of worldwide research into coal bursts. It focuses on two major longwall mining coalfields that have struggled with bursts for decades. The Utah experience displays many of the ‘classic’ burst characteristics, including deep cover, strong roof and floor rock, and a direct association between bursts and mining activity. In Colorado, the longwalls of the North Fork Valley (NFV) also work at great depth, but their roof and floor strengths are moderate, and most bursts have occurred during entry development or in headgates, bleeders or other outbye locations. The NFV bursts also are more likely to be associated with geologic structures and large magnitude seismic events. The paper closes with a brief discussion of how US longwalls have managed the burst risk.CITATION:Mark, C, 2014. Coal bursts in the deep longwall mines of the United States, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 33–40 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

Discovered in 1954 and mined since 1966, the X41 copper orebodies have produced over 143 Mt @ 3.3 per cent copper. By June 2002 the production from these orebodies had depleted the Mineral Resource to 36.6 Mt @ 2.8 per cent Cu (including 31.5 Mt @ 2.5 per cent Cu combined 2002 Ore Reserve). Mine production will ramp down to cessation beyond ten years. The 2002 Copper Business Study was commissioned to review the status of the Mount Isa copper business and to optimise the long-term strategy of the operations. The study resulted in a vastly improved geological and geostatistical model, and financial studies led to the optimisation of mine cut-off grades. Utilising these new models, a near-mine target generation workshop was conducted by the copper stream geology team. The workshop focussed on exploration for new ore sources and the extension of existing orebodies to supplement the Mineral Resource inventory for future conversion to Ore Reserves. Several prospective targets were identified and the Conceptual Northern 1100 Drilling program was subsequently designed. This paper shall discuss the practicalities of near-mine target generation in Mount Isa, the issues faced when locating and preparing drill sites in a mature mine environment, and the preliminary results of the drilling program so far.

Jan 1, 2003

To obtain the best economic results in treating the comparatively high-grade ore of the Kalgurli Mine a good roast is essential, and the effort of this paper will be to briefly describe the plant and the conditions prevailing in roasting, which, on an output of about 360 tons daily, subsequently enable an average extraction of slightly over 94% of the gold to be maintained.The percentage of sulphur in the ore varies between 2'5 and 3'5, the lower figure existing when treating oxidized ore. The average gold value is 13 dwt; this occurs chiefly as sylvanite, containing .a lower percentage of silver than is usually present in that mineral. One ore body in the mine contains hessite (Ag2Te) in considerable quantity, associated with gold telluride, and when ore from this stope is being treated the silver contents rise to as high as 20 dwt, but the usual amount is about 9 dwt. per ton, of which only a small proportion is extracted. Other metallic minerals, in addition to pyrite, occurring more or less commonly, are arsenopyrite, magnetite, chalcopyrite, and the tellurides calaverite (AuTez)and coloradoite HgzTe3). A small proportion only of the value occurs as free gold.

Jan 1, 1911

By J Pan, T Chun, D Zhu, Z Guo, J M. Young, T C. Ooi

With the rapid development of the Chinese steel industry, the strong demand for iron ores has led to huge imports of various iron ores from all over the world. As a relatively new force in the iron ore world and an important raw material supplier, Fortescue Metals Group (FMG) has achieved an annualised production rate of 100 Mt of iron ore fines. Typical blends were designed to simulate sinter blends employed in Chinese steel mills, and to determine sintering properties and metallurgical performance of blends comprising FMG Rocket fines in pilot sinter pot. It is shown that the sinter of typical blends comprising 15 - 20 per cent rocket fines possesses excellent sintering properties and metallurgical performance. With Rocket fines substitution for competitor ores in a typical customer mill blend comprising fully imported fines, the sinter productivity and tumble index increased from 1.45 t/m2h and 62.0 per cent to 1.54 t/m2h and 64.0 per cent, respectively, while attaining similar reducibility index and reduction degradation index at lower solid fuel consumption.CITATION:Zhu, D, Guo, Z, Ooi, T C, Chun, T, Pan, J and Young, J M, 2013. Sintering and metallurgical performance of blends comprising Fortescue Metals Group rocket fines, in Proceedings Iron Ore 2013 , pp 519-524 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

Commencing early in 1975, Saraji Mine in Central Queensland will product 3.56 million tonnes in the first year and then 4.57 million tonnes annually for the Japanese and European markets. The coal will be mined from a series of pits separated by corridors which will be mined at a later date. Through the corridors flow regional drainage structures and power lines. Relatively easy areas will be mined initially to assist the cash flow and to minimise start-up difficulties. For ease of scheduling it is desirable that pit lengths exceed 3 000m but this will not always be possible. Ramps were designed using 1 200m spacing and 5 per cent gradient as optimum but modified to suit specific conditions. One ramp will be in the end of each pit nearest the ROM hopper and stripping will commence from this end. The advantages so gained are shorter haul distances, immediate access to the coal after stripping and simplification of the excavation of the first ramp. Haul road location was defined by the minimum present value of construction plus operating costs. Road design utilised airfield construction charts because wheel loads were outside the range of available road design manuals. Low load resistance characteristics of

Jan 1, 1974

By Baafi EY, MacKenzie -Wood P

An experienced and reliable knowledge of fire fighting procedures is necessary for mine emergency situations. Since experts in this area are scarce the technology of expert systems lends itself as a suitable component in the decision making process. This paper describes an expert system that is being developed for this purpose. The expert system. RESCUE. is a knowledge-based computer programme which incorporates the judgement, experience, rules of thumb. mine environmental conditions as well as human intuitions in the mine rescue operation. RESCUE makes decisions such as whether or not the affected area should be sealed.' whether or not rescuemen should be withdrawn, and which fire fighting agent is most appropriate for the situation. The IF..... THEN rules written in the VP-EXPERT shell contains antecedents and conclusions based on environmental as well as other conditions prevailing in the mine. For example, the CO/Oz deficiency ratio indicates the progress of heating; explosibility trends are given by varying flammable gases C CH4,H2,CO) in relation to oxygen concentration, and barometric pressure falls may affect explosibility by increasing CH4 content in workings. The interaction of such numeric-based rules with others rules reflecting the experience and judgement of the experts assist the system to arrive at its conclusions and subsequent course of action.

Jan 1, 1988