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By B Twidle, D Bertoldi, J Meikle, R Dunne

The Waihi Gold Mine is situated in a high rainfall area (annual average of over 2 m) on the North Island of New Zealand. Water treatment and discharge at the mine has been ongoing for the last 25 years. The first water treatment plant consisted of a æstandardÆ water treatment facility (ferric chloride precipitation) and cyanide detoxification. With time the project has expanded and the volumes of water increased requiring additional treatment methods (reverse osmosis) to meet the water quality for discharge. This paper will provide information on the historical development of the water treatment flow sheets, performance data and operating costs.CITATION:Bertoldi, D, Dunne, R, Twidle, B and Meikle, J, 2013. Water treatment at the Waihi Gold Mine, in Proceedings World Gold 2013 , pp 503-508 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By A Radici, M Attwill

The Dampier Port Upgrade Project (DPU) involves an upgrade to Hamersley IronÆs Parker Point iron ore port facility at Dampier, Western Australia. The $US700 million DPU Project will increase Hamersley IronÆs shipping capacity at Dampier from 72 million tonnes per annum (Mtpa) to 116 Mtpa. The DPU Project comprises a new car dumper facility and rail spur, an upgrade to the existing stockyard and conveying system, a new screen-house and a 450 m wharf extension with two new shipping berths and a new ship-loader. This paper discusses the innovative design and construction of the new car dumper facility, which is capable of automatically unloading 240 car iron ore trains at a rate of 10 000 t/h. The facility design is unique compared to more conventional designs currently in operation, and greatly improves operation and maintenance functions.

Jan 1, 2005

By M Berry

Consider these four questions:What is the definition of life-of-mine?When should life-of-mine planning seriously commence?When can life-of-mine planning seriously commence?What is the key input to effective life-of-mine planning?Whilst there is likely to be general consensus on the answers to the first three questions, the answer to the fourth question is open to debate. This author argues that understanding and managing risks and opportunities associated with geological uncertainty is the key input to effective life-of-mine planning, at all stages in the life cycle of a mining project.CITATION:Berry, M, ?2014. Effective life-of-mine planning by understanding and managing risks and opportunities associated with geological uncertainty, in Proceedings Life-of-Mine 2014 , pp 183–190 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By D M. Frantois-Bongarton

Variograms can be powerful tools for the analysis and control of process streams and their sampling. Their uses and proper utilisation have been described somewhat unclearly to date, and their limitations and precautions of use are too rarely mentioned. The general meaning and properties of the variogram tool and its use in geostatistics are therefore reviewed in details to derive a critical view of its proper use for process control: what to expect from it and what it cannot deliver and which uses are illusory or potentially misleading. A summary of GyÆs seminal work accompanies this essay to put the concepts into historical perspective.CITATION:Frantois-Bongarton, D M, 2012. Review of variogram properties and remarks on its use in process control, in Proceedings Sampling 2012 , pp 175-180 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

By D M. Frantois-Bongarton

"A few situations are first reviewed where practical shortcuts lead to acceptable solutions where none seemed to be possible. These include: The solving of many complex sampling optimisation problems with the simple approach of the worst case policy (WCP). A simple approach to single-stage sampling problems will be mentioned at continuation. In the plants, minimising the impact of border effects in incorrect samplers, so that the resulting samples are approximately correct and acceptable in practice because the bias risk attached to them is controlled. Examples are given, as well as practical tools and a general methodology.Finally, some sources of undue conservatism are reviewed with general recommendations aiming at eliminating them.CITATION:Frantois-Bongarton, D M, 2012. Practical considerations and shortcuts in sampling, in Proceedings Sampling 2012, pp 171-174 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 21, 2012

Mining companies around the world are seeking methods to coordinate operations between the mine and the concentrator to achieve an overall improvement in enterprise performance. In several instances very significant increases in productivity (more than 20 per cent) and profitability (more than $US 10M per annum) have resulted from such efforts. The key to realising these large benefits has for the most part arisen from improved communication between mining operations and plant operations personnel and the judicious use of new tools to evaluate alternatives for improvement and to minimise the risk of implementation. This paper presents a systematic approach to mine-to-mill optimisation . The importance of systemic thinking and systems optimisation methodologies is emphasised. New tools for evaluating operational performance are discussed. Recently reported benefits are summarised. Finally current research is discussed and projections for the future are given.

Jan 1, 2000

Teller Underground Mine was established to extract ore from the Middle Vale Reef located on the eastern flank of Telfer Main Dome.The mine is located below a 150 m deep open pit operation. The ore body is shallow dipping highly structured, and is a main aquifer in quite difficult ground conditions.In respect of these conditions it was determined to access the orebody using an adaptation of coal mining and hard rock mining methods, with support being achieved using a combination of island pillars, rock bolts and timber stalls.The paper will describe these methods in more detail, then discuss the successes and failures of these methods when put into practice. As well, it will detail several factors whose influences were found to be greater than previously expected and stress the importance of good geotechnical advice.

Jan 1, 1993

By Real F, Carvalho P

During the development of the Neves-Corvo Underground Copper Mine, since 1981, inflow of water has been encountered in the mine workings, which consist of a ramp from surface 5 km long, a shaft 575 m deep and access crosscuts through the massive sulphide orebodies of Neves, Corvo and Graga, which are three of the four known deposits up today. Mine-hydrological studies have established the main characteristics of the hydrological system and its evolution in space and time. In a geological setting of low permeability rocks of Paleozoic age, tectonically affected by thrusts and faults, this has involved consideration of the relation with surface and ground water as a result of mine dewatering processes. The hydrological systems are described and summarized in this paper together with the techniques employed to study their origin and evolution, namely hydrochemistry, thermometry, piezometry and isotopic tracers.

Jan 1, 1988

By Baynes F. J, Bermingham A. G

The 6000m long King Headrace Tunnel will be driven through hard Owen Conglomerate in the Eastern third and feldspar porphyry in the Western two thirds, with the anticipated hardness up to 350MPa unconfined compressive strength. Since the Commission had not driven a long, large diameter tunnel for some twenty years, major research was undertaken to assess the current tunnelling trends. Tunnel boring machines were compared with drill and fire equipment. Rail equipment was compared with rubber tyred equipment. Tenders were called with tenderers invited to submit alternatives if desired. Commissioning and production excavation using the equipment is discussed with the final conclusion being that the individual items of equipment purchased combined to make an efficient hard rock drill and blast system capable of progressing through all rock conditions likely to be encountered on the King and Anthony Schemes.

Jan 1, 1987

By Turco E, Pelizza S, Vona A

Within the project against pollution in the Gulf of Naples (Italy) it was envisaged to build a sewage collection tunnel whose tunnelling section is about 30 m2 and whose length is over 4 km. The formations to be bored through feature heteregeneous volcanic deposits made up of either lenses or lava, lapilli and pozzolan layers and ashstone silts. The cover ranges between 10 and 30 metres. The surface is heavily built-up requiring then an accurate monitoring and reduction of noise, vibrations and settlements. The building of the tunnel is therefore carried out by means of a boom tunnelling machine equipped with a mechanized shield. Support along the complete excavation perimeter is provided by linerplates together with an immediate cement grouting behind them. At a later stage the concrete lining will be cast in place.

Jan 1, 1987

By Robinson J

A stibnite flotation concentrate from Costerfield in Victoria was found to contain 63.3 g/t An while its sizing distribution indicated that 81.6 per cent of the material was less than 38 ¦m. A 24 hour cyanidation test by a standard bottle roll method recovered 15 per cent of this gold. Pressure cyanidation under conditions of ambient temperature, 40 per cent pulp density, an oxygen pressure of 1000 - 2000 kPa and an initial NaCN concentration of 15 kg/t, resulted in a recovery of 65 pe cent of the gold after only two hours of leaching. Aqueous pressure preoxidation of the concentrate followed by the standard bottle roll cyanidation realised gold recoveries as high as 96 per cent. Conditions of 220¦C, an oxygen pressure of 1000 - 2000 kPa, 16.7

Jan 1, 1991

By Schlanger H. P

A theoretical model for gas outbursts in underground coal mines is as follows. An outburst is the structural failure ofcoal due to excess stress resulting from body forces caused by gas pressure gradients. These body forces influence the stability of a mine face in the same manner that gravitational body forces affect the stability of the roof of a mine. The magnitude ofthese body forces can be appreciated when it is realized that for an average density coal, the gravitational body force is equal in magnitude to the force from a gas flow with a pressure gradient of 14 kPa m-I. Gas pressure gradients and the resultant stresses within a seam can be calculated with numerical methods. Thus, providing the necessary parameters can be measured or estimated, in principle the theory can be applied to compare the outburst risk of various mining arrangements.

Jan 1, 1985

CONTENTS.IntroductionAcknowledgementsDescription of MineVentilation of MineOrganisation of Fire Fighting SquadsTraining of Fire Fighting SquadsRescue WorkFire Fighting and Rescue EquipmentFire AlarmsConclusionINTRODUCTION.This paper should be read in conjunction with that by R. P. Hooper, entitled "Underground Mine Fire Prevention at the South Mine," Broken Hill. Contents of the paper have been arranged similarly for easy reference. The methods used in educating employees in the use of Proto apparatus remain basically the same, but many changes in the methods and equipment used in subjugating fires have been brought about by the practical experiences gained by officers of the company in extinguishing the outbreaks which occurred in the latter half of 1944.Three fires took place during this period, the first in July, on M.L. 11 in openings leading to timbered workings previously worked and subsequently abandoned by...

Jan 1, 1946

By M Behrens

The Melbourne Main Sewer Replacement (MMSR) is a major urban infrastructure project involving approximately 2.3 km of tunnelling and construction works. The works extend from Docklands Precinct, on the southwest edge of the city, southwards to connect with the Hobsons Bay Main Sewer in Port Melbourne. The tunnel boring machine (TBM) tunnelled section of the works terminates at the Yarra River where the delta geology and alignment requirements precluded the use of underground tunnelling methods. The 132 m long river crossing works involve a cut-and-cover excavation within a staged fl ooded cofferdam construction to construct an immersed tube tunnel as an extension of the TBM works.This paper reports on the development of the staged construction method and highlights the geotechnical and structural design aspects involved in building a new sewer in the Yarra River to close the gap between the new TBM driven and pipe-jacked tunnels.

Mar 8, 2011

By K Uchino, M Inoue

Self-potential anomalies are generated by fluid pressure gradient, by temperature gradient or by chemical gradient. On the basis of this principle, a new technique is proposed to locate the fire source of spontaneous combustion of coal by the self-potential method. In order to investigate whether this method can be applied to locate the spontaneous combustion of coal in practice, surveys of self-potential distributions were undertaken in a coal waste pile undergoing spontaneous combustion. The results showed that there is a negative centre of the electrical potential distribution in the measurement area. The potential in this centre is about 140 mV lower than that in the surrounding area. Moreover, the negative centre of electrical potential distribution almost overlaps with the high temperature zone. Therefore, it is concluded that it is possible to locate the heat source by the measurement of self-potential distribution.

Jan 1, 2005

As part of a prefeasibility study being undertaken by Newcrest Mining Limited, the Cadia East Implementation Team has developed an access decline to the proposed underground operation. This paper describes new technologies that have been employed in this development, which include: high frequency drifters that have penetration rates one and a half times that of competitors, ensuring minimal increase in drill time, despite rounds greater than 5.5 m;automated drilling used in conjunction with laser navigation and face pattern design software, which facilitates exact positioning of hole collars, lengths and lookouts for accuracy and repeatability; andemulsion charging that reduces manual handling; has variable string loading capabilities, via its hose retraction system, for perimeter control and reduced fume characteristics. A Six Sigma improvement process was used to support the system change undertaken and demonstrated that development rates improved 60 per cent above the comparable single heading benchmark.

Jan 1, 2008

The lignite mines in the Latrobe Valley of Victoria/Australia have been using continuously operating mining systems for more than 50 years. The relatively small bucket chain dredgers of the early years have been progressively displaced by bucket wheel dredgers with increasing size, increasing capacity and increasing service weight. The large machines for the new open pit Loy Yang have a bucket wheel outreach of 46m, an effective capacity of 3350 bm' coal/h respective 2500 bm' overburden/h and a serv- ice weight of approx. 4500 t. The time between signing of con- tract and starting of operation for these machines is at least four years. The high service weight, the resulting high capital invest- ment and the long period for design, design review, manufac- turing, erection and commissioning of these machines directed the SECV to investigate a possible application of compact dredgers for the Latrobe Valley.

Jan 1, 1989

Within the Mt Whaleback open cut mine the integrity of the final pit wall is achieved through careful rock slope design, use of rock reinforecement technology where marginal stability exists and use of controlled blasting techniques and excavation practices. By reducing the effective density of ANFO explosive within blastholes to around 0.2 glcm', and developing standard blast pattern designs for various rock types, blast damage to pit walls has been minimised. Accurate geological prediction is necessary for optimum blast design. Controlled blasting is undertaken where blasting occurs within 90 m of the designed final batter crest and hole by hole assessment of final limit blast patterns is undertaken before pattern charging. Shovels and trucks remove the bulk of blasted and dozed rock material, but due to the mine's variable pit wall slope configuration, bulldozer excavation of some critical design batters has been successfully Implemented.

Jan 1, 1986

By B Shen

The Wambo Rail Spur located near Singleton, New South Wales, Australia, runs for approximately 14 km linking the Mt Thorley rail loop and the Wambo Coal Mine. The project involves a 260 m long tunnel in weathered sedimentary and intrusive materials. The tunnel has a low cover and runs under a main highway. This second paper on the project looks into one aspect of the tunnel in detail: the use of shotcrete arch as the primary support for part of the tunnel excavation. The use of shotcrete instead of steel arch, formulation of the material specification, construction sequencing, installation at the excavated face and material testing for verification related to this facet of the project will be discussed in this paper. The tunnel opened in April 2006, and two years on, we briefly reflect on the impact of this design decision on the overall project.

Jan 1, 2008

By Savidis GM

This report outlines the experience of Australian mining operators in dealing with large falls of roof in advance of longwall supports. Previous and present techniques used for face stabilisation have been described, together with an analysis of [actors which contributed to the roof falls, in each case. Attention has been focused on the stabilisation technique used at Angus Place Colliery, where the face coal was successfully reinforced by injecting chemical foam into Lite fractured areas. Although considered to be one of the worst roof falls in the history of Australian longwalls (60 m in length and up to 10 in in height), it was subsequently possible to resume cutting in Longwall 9 two weeks after the foam injection. A preliminary schedule of work involving the 'strata replacement' method, is also discussed. It has been based substantially on experience gained with cementitious supports, principally by ACIRL and Monier Resources.

Jan 1, 1986