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By D Thomas, B Gallagher

Valuable data for geotechnical interpretation and integration into effective Australian underground mine planning may often be available, yet is not always fully appreciated or utilised, particularly in the early stages of mine planning or in due diligence studies. There may be considerable benefits associated with early prioritisation of geotechnical evaluation and impact on mine planning. Unidentified, misinterpreted, or ill-defined adverse geological and related geotechnical resource characteristics can pose significant business risk to underground coal projects and operations. Preliminary resource definition in the early conceptual mine planning stages attributes significant focus (entirely warranted) on resource quality and structural geology constraints. Yet detailed geotechnical data analysis and interpretation, which may have a substantial down stream impact and sensitivity with respect to future mine planning strategies, at times is given lower priority, or scoped and resourced in the later stages of a bankable feasibility study. Through extensive mine planning experience and observation of downstream process impacts, it has been found there is often data available for geotechnical analysis that does not readily stand out or is not adequately understood or utilised, available at the early (conceptual) stages of mine planning. Part of the issue may be that exploration geologists are not necessarily experienced geotechnical engineers and do not necessarily recognise or understand all important parameters. Subject to appropriate application of experienced professionals data can be manipulated to provide key geotechnical hazard assessment at minimal cost, and provide a framework for understanding and optimising the mine planning process. Although there is no single prescribed strategy for resource evaluation from a geotechnical perspective, potential business risks and mitigation approaches can and should be adopted at the conceptual mine planning stage. There has been a recent focus in the metals industry to provide a reporting framework for geotechnical classification of mining projects. This paper outlines the strategies and gives examples of key analyses adopted in mine planning and discusses the relative merits of adopting a reporting framework as a tool for geotechnical classification in mine planning.

Jan 1, 2005

SOME notes on the works of the Electrolytic Refining and Smelting Company of Australia will no doubt be of interest to members of the Institute, more especially as much of the work is new to Australasia.As many of the members who may read this paper have not been in a position to visit works of this kind, and are consequently not thoroughly acquainted with all the operations carried on, the author has taken the liberty, in some cases, to enter into explanation which would otherwise be unnecessary.The works are situated at Port Kembla (New SouthWales), about fifty miles south of Sydney, and are approachable both by rail and water. The Government has recently built a low-level jetty upwards of five hundred feet long, and intends installing at an early date an electrically operated portable crane to facilitate the handling of material to and from the boats. Thi.s will mean a considerable reduction in the length of time that boats are laid up at the jetty. There are also under construction two breakwaters, which, when complete, will materially assist shipping operations. The works as they exist are capable of turning out 1200 long tons of refined copper per month. It is gratifying here to note the unqualified success with whichthe E.S.A. refined copper met with on first being put on the market.

Jan 1, 1911

Mining is taking place at increasing depths of cover on the Southern Coalfield beneath pre- dominantly massive sandstone strata. Within the next twenty years, there will be longwall mining at depths greater than 600 m. As the Sydney Metropolitan area continues to expand and as coal mining approaches these urban areas subsidence will continue to become an increas- ingly important aspect of coal mining research. Investigations commenced in the mid 1960's and it is now possible to predict subsidence in the Southern Coalfield with reasonable con- fidence. The work is showing that the characteristics of the subsidence troughs over the deeper mining at Appin differ from the characteristics of mine subsidence at less cover. The longwall mining at Appin Colliery has resulted in a maximum measured subsidence of 730 mm. The maximum strains were small because of the large radii of curvature of the subsidence profiles. There was no damage to any of the buildings in the township of Appin.

Jan 1, 1981

This paper describes the operation involved in the sinking of a concrete-lined elliptical-shaped shaft at North Broken Hill Limited.Major factors such as geological features, future ventilation, ore haulage at depth and their relation to the location and selection of the type of shaft are described.Features covered in the sinking of the shaft include equipment details, with special reference to mechanical mucking, operational cycles based on time study analyses for sinking, concreting and the placing of steel sets. Safety precaution and statistical data is alsoincluded.INTRODUCTIONDue to the northerly pitch of the ore bodies in North Broken Hill Limited leases at approximately 42°, and the deepening of the active mining zone, it became apparent that No. 2 Shaft, the main operating shaft, would become unsuitable for the extraction of ore from the lower levels.Another major problem was the ventilation of the lower levels, and it was evident, that to ventilate efficiently these, and deeper levels, another upcast ventilation system would be required.Consideration was given therefore to the following: 1. Sink No. 2 Shaft from the existing bottom at 2770 ft. to 4200 ft., or Sink an internal shaft from the 2600 ft. level approximately 1000 ft. N. of No. 2 Shaft.2. Sink a new haulage and downcast shaft from the surface.3. Sink a new upcast ventilation shaft from the surface.It had been suspected that the ore bodies might flatten or even undergo a pitch reversal before reaching the...

Jan 1, 1956

The introduction of large diameter drill holes and mass firings in underground metalliferous mines has led to an increase in the number of reported sulfide dust explosions in Australia and overseas. Adaptation of the coal mining technique of using limestone to inhibit or prevent dust explosions has not been entirely successful as the development and inhibition of a sulfide dust explosion is somewhat different from that of a coal dust explosion. Tests were carried out on two pyritic ore samples, sulfur contents of 41 and 36 per cent, in 8 and 20 litre explosion chambers to evaluate the effect of the addition of limestone on the maximum explosive pressures developed and rates of pressure rise. Significant values were obtained in both chambers with dusts containing 60 per cent ore and 40 per cent limestone. The percentages of limestone required to inhibit the pyritic dusts were considerably higher than those values generally accepted by the mining industry and the current methods used to inhibit sulfide dust explosions should be re-evaluated.

Jan 1, 1986

By Melcher G

The challenge to the zinc industry is shifting from maximum metal recoveries to the environmentally safe processing of the ore concentrates. The main source of solid residues from hydrometallurgical zinc processing is the iron content of the concentrates. Unfortunately iron precipitates from leach liquors contain various compounds which cause them to be considered as environmentally unsafe, unless they have been cleaned in subsequent process steps. This calls for separating the iron from hydrometallurgical processing as early as possible. For this purpose a process has been designed to eliminate the iron directly after neutral leaching the calcine. This is being done by direct smelting the neutral leach residue with a cyclone/top blowing unit. The zinc is recovered from the neutral leach residue as a metal oxide to be recycled to the zinc process. The iron is converted to a slag, which is resistant to atmospheric attack. Key data of the integrated hydro-/pyrometallurgical process are presented as derived from pilot plant tests by cyclone smelting and top blowing the slag.

Jan 1, 1993

By R Lau

In recently completed road tunnel projects in Queensland, such as the Airport Link and the Clem7 tunnels, there is a smoke duct running along the roof of the carriageways to extract smoke in case of fire. In New South Wales, no road tunnels have a smoke duct. In the Melbourne City Link tunnels, there is a small smoke duct running along the roof. All of the tunnels are safe as claimed by the designers and authorities. However, there is significant cost associated with providing a full size smoke duct compared with no smoke duct. This paper is going to present a comparison of the road tunnel safety with a smoke duct and those without one from a risk perspective. It further discusses the cost-effectiveness of such provisions and whether similar levels of safety could be achieved without a smoke duct.CITATION:Lau, R, 2014. Smoke duct or no smoke duct for road tunnels, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 83–86 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Parr JM, Scott SD, Herzig PM, Gemmell JB

PACMANUS is an actively-forming seafloor analogue of volcanic-hosted massive sulfide orebodies, situated on the crest of an andesite-dacite-rhyodacite ridge overlying rifted older arc crust in a back-arc basin. Hydrothermal deposits range from Mn-oxide crusts to Cu-Zn-rich massive sulfide mounds and chimneys containing significant Au and Ag. Preliminary data suggest a substantial magmatic component to fluids and metal sources, and we speculate that PACMANUS is the cap to a complete hydrothermal system including subvolcanic and intrusive-related mineralisation.

Jan 1, 1995

By Guo H

The importance of using disc cutters for rock excavation is reflected by their wide application in hard rock cutting machines such as tunnel boring machines and raise borers. The forces involved in the cutting process are those due mainly to thrust and rolling forces and are greater than that required by cutting picks. An interesting feature of cutting with discs is the formation of surface crushing, surface and sub-surface chipping and primary crack formation. Experimental, as well as analytical, work has been carried out to determine the optimum spacing between the disc cutters to control primary crack orientation. Wedge bit indenters were used to simulate disc cutters. The paper concludes by proposing a new approach to rock excavation by hybrid cutting based on controlling the primary crack Orientation.

Jan 1, 1992

By M Pratt

For up to 75 years large scale coal mining has been carried out within the Latrobe Valley region of Victoria. Withdrawal of groundwater from Tertiary aged sediments within the Latrobe Valley is essential to allow coal mining to proceed to depth. Water within the overburden layers, coal seams and interseams must be drained to avoid flooding during the mining process. The pressure in deeper aquifers must also be lowered to avoid floor heave, batter instability, and to maintain safe operating conditions as the mines develop in size and depth. The cost-effective management of the groundwater systems at and adjacent to the mining operations in the Latrobe Valley is essential to enable the efficient utilisation of the coal resource whilst minimising the environmental impact of this major industry in rural Victoria. Large-scale depressurisation and dewatering programs within the Latrobe Valley mines are managed through the use of detailed groundwater management plans. These incorporate:an extensive monitoring network which extends up to 60 kilometres from the mines; detailed mine scale and regional groundwater and hydrogeological models; and established operational procedures aimed at minimising capital and operational costs associated with the mine groundwater systems. Groundwater extraction system optimisation programs have been introduced into two of the mines with the aim of reducing extraction rates, improved risk management, and reducing operational costs by approximately whilst not compromising mine safety. This paper reviews the aquifer depressurisation and mine dewatering operations of the Latrobe Valley mines and illustrates the techniques utilised to ensure that high artesian pressures do not adversely impact on the mining operations.

Jan 1, 2003

By Tsuchida N

The history of world nickel production has been affected significantly by the supply and demand situation and fluctuation of LME price of nickel metal. In the beginning of the 1980s, the decline of price and demand lead to the withdrawal of un-competitive producers and the shrinkage of the production capacity. During the same period, Sumitomo Metal Mining maintained the production level with continuous improvement of the traditional matte electrorefining process. However, Sumitomo has recognised that the continuous improvement alone does not promise us the ability to catch up with rapid changes in the world. In the meantime, Sumitomo intensively researched chloride hydrometallurgy and has developed the chloride process for the nickel refining. This includes the solvent extraction and chloride electrowinning in the mixed sulphide process and the chlorine leach of the anode slime arising from matte electrorefining. In the late-1980s, Sumitomo Metal Mining decided to develop a new nickel refining technology based on chloride hydrometallurgy. The new process was designed from the comprehensive aspects involving safety and the environment. Construction of the plant for the matte chlorine leach electrowinning (MCLE) process was commenced in 1991. The MCLE plant with a capacity to 2000 tonnes per month has been commissioned at Niihama since 1992. The process has provided high productivity, overall good economics and high quality of electrolytic nickel produced. After the establishment of the process, Sumitomo has maintained continuous improvement of the new process and has attained the best practice of the work classification.

Jan 1, 1996

The Circum-Pacific area is one of the most important gigantic skarn-metallogenic belts in the world. In more than 20 coastwise countries of this region, there exist thousands skarn deposits of different types. According to the differences of major metallic elements, the skarn deposits may be classified into seven subtypes, i.e. Fe, Cu, Pb-Zn, W, Sn, Mo and Au skarn deposits. In this paper, the distribution. and geological characteristics of above-mentioned types of skarn deposits are described briefly. Skarn deposits may also be classified on the basis of the dominant calc(magnesian)-silicate mineral assemblages into four types: magnesian, calcic, manganoan, and alkaline skarn types. Magnesian skarns may be associated with Fe, Cu, Au,, Sn, B, Be mineralization, calcic skarns with Fe, Cu, W, Mo, An, Be, Pb, Zn, Sn minerailization, while the alkaline skarns occur in U(Th, Nb) deposits. The skarn deposits of both East and West Pacific rims have many general characters, but have some diferences in geotectonic settings, intensities of mineralization, distribution, and metallogenic epoches. In this paper, the minerogenetic series and the mineralizing specialities of related magmatic rocks of the skarn deposits are also discussed.

Jan 1, 1990

By Gupta A, Hall ST

The grinding characteristics of quartz which is normally associated with gold bearing ores in Kalgoorlie area was examined in a stainless steel laboratory size ball-mill in the presence of inorganic and organic surface active reagents. The cationic species considered were Fe3+, Cu2+ and Ca2+, and the anions were CO? and S2 as these are normally present during the process of grinding of gold ores in the region. The organic surfactants examined were K-amyl- xanthate, dodecylamine-hydrochloride and the Grinding Aid XFS-4272 manufactured by Dow Chemical The study was primarily based on an examination of the electrokinetic properties of quartz surface in the presence of the grinding reagents. Zeta potential at different reagent additions and pH values in the presence of individual reagents were examined and the corresponding grinding charcteristics determined. A correlation has been indicated between the grinding characteristics, as measured by the -53um size fraction produced, and the surface energy of quartz. It was observed that an

Jan 1, 1978

By A S. Venkatesh, A Das

The Precambrian iron ore of Singhbhum-North Orissa region of eastern India occurs as part of the horseshoe-shaped broad synclinorium known as the Iron Ore Group (IOG) of rocks, which hosts the most important iron ore deposits in India. The Jilling-Langalota iron ore deposits are part of the IOG. Detailed mineralogical characterisation of different ore types has been carried out using transmitted and reflected light microscopy. Scanning electron microscope-energy dispersive spectroscopy (SEM- EDS), X-ray diffraction (XRD) and X-ray fluorescence (XRF) have also been used with a view to test the amenability of these ore types for beneficiation requirements. It has been observed that haematite, martite and goethite are the main iron-bearing minerals. Kaolinite and quartz are the major gangue mineral phases. Considerable mineralogical, textural and compositional variations have been observed among the different ore types. Characterisation data reveals that the massive and hard-laminated ores are of higher grade with very few interlocking textures having haematite and martite as major mineral constitutents. The soft-laminated lateritic and friable ores are relatively low-grade varieties containing various proportions of impurities with complex interlocking textures. The soft-laminated and lateritic ores are porous in nature and contain friable oxide and hydroxides of iron along with kaolinite, gibbsite and quartz. The occurrence of kaolinite, gibbsite and hydrated oxides along the cavities and weaker mineral planes of haematite and martite has been observed. The friable nature and high alumina content of these ores are attributed to these secondary phases. The nature of these ores is responsible for producing large amounts of alumina-rich slime during mining and handling operations. Suitable beneficiation schemes have been recommended for each type based on detailed characterisation investigations on these ores.

Jan 1, 2007

By A Boucher, M Baudin, P Androszczuk, I Minniakhmetov, A Rigby, P Machado, M Wright, B Van Dijken

IGO Ltd’s (IGO’s) Nova Operation (Nova), which is 160 km east-north-east of the town of Norseman in Western Australia (WA), mines and processes nickel-copper-cobalt (Ni-Cu-Co) sulfide ore from the magmatic Nova-Bollinger Deposit (Nova-Bollinger), which is hosted by the Mesoproterozoic age high-grade metamorphic rocks of the Albany Fraser Orogen. Over its 56-month life-of-mine (LOM) operations to 31 December 2020, Nova has processed 5.63 Mt of ore grading 2.04 per cent Ni, 0.86 per cent Cu and 0.07 per cent Co from its underground mine. At the end of 2020, both the Nova-Bollinger JORC Code reportable Mineral Resource estimate (MRE) and Ore Reserve estimate (ORE) were >90 per cent classified in the highest JORC Code confidence categories of Measured Mineral Resource and Proved Ore Reserve respectively. The high JORC Code classification confidences assigned to the Nova-Bollinger MRE and ORE results from the 386 km of surface and underground diamond drill testing of the deposit to a nominal 12.5 by 12.5 m pierce point spacing in mineralisation. The close spaced high-quality drilling and bulk mining method employed at Nova has effectively removed the need for any grade control modelling outside of the MRE process. Importantly, having only the one fully drilled out deposit being mined and only the one process plant, Nova’s reconciliation process is in the fortunate situation of not being confounded by issues such as external ore sources and constant updates as new grade control information becomes available. IGO’s Nova reconciliation processes are focused on reconciliation ratios that quantify operational period differences between the MRE and ORE head grade and tonnage forecasts and the process plant head actuals. These metrics have been used to identify key reconciliation issues and have initiated several studies into the causes for specific reconciliation results, which are discussed in the paper. In late 2020, a period of sustained poor reconciliation results led to the recognition that increasing the understanding of risk between the MRE and ORE should be investigated. To assist with modelling stope level risk within the mine plan and subsequent reconciliation, an attempt was made to develop a formula to quantify ‘stope risk’ from MRE metrics such as sample spacing, kriging efficiency and so on

Mar 22, 2022

By M E. Pierce

Recent advances in comminution and heap leach technology have resulted in the development of many large-scale, low-grade open pit mines that coincide with areas of historical underground workings. Twoand three-dimensional numerical modelling has been conducted to assess the interaction between open pit slope stability and remnant underground voids. Most design analyses for open pit slopes assume a two-dimensional problem geometry. This is not the condition encountered in practice ù particularly when remnant underground voids interact with a large-scale open pit slope. Three-dimensional numerical models have been shown to provide a more realistic representation of the interaction between overall open pit slope stability and remnant underground voids.

Jan 1, 2003

By Corbett G, Iwai N

The Japanese gold mining industry has a long and productive history and is presently undergoing a period of revitalisation encouraged by the Hishikari discovery. Deposits exhibiting the characteristics of epithermal mineralisation are very widely distributed throughout the island chain and an encouraging number of these are large, seven containing gold in excess of one million ounces. All the important deposits are quartz vein type and contain extremely high grade, or "bonanza". Zones.

Jan 1, 1990

By Bin H

East Guangdong tin province overlaps the southmost part of the mesozoic magmatic arcof continental margin type in Southeast China and is dominated by mesozoic syntectic magmatism,which associated to tin mineralization. It is distinguished from Nanling tin province but quite close to NW Bolivian tin province in both tectonic and magmatic relations.Tin deposit's mostly of cassiterite-sulfide, cassiterite-silicate formations are localized along exsocontact zone of granitoid batholith or stock, boundary area of volcanic depression, or, within volcanic edifice. Petrochemistry studies show tin was concentrated as intermediate-acidic magma evolved by fractional crystallization. Xiling tin deposit of vein type related to extrusive... the lava dome was formed at T C 221-301 and at very shellow depth,seems to correspond to type A in classification for Bolivia tin deposits by J.N.Grant. Tashan tin deposit of dissemination type related to hypergene intrusive facies,with mineralization occured in endocontact zone of granite porphyry dykes is considered as porphyry type,which spported by H-0 isotope and gas-liquid inclusion evidences. It formed at T C 250-430, comparable to Bolivia porphyry tin deposits,but at a greater depth 1.3 3.0km.A model for known tin deposits in East Guangdong was worked out. A good prospecting perspective was revealed for the potential type of tin deposit in East Guangdong--subvolcanic porphyry tin deposit.

Jan 1, 1990

Lake Kopiago is located some 71km northwest of Tari in the Southern Highlands Province and lies on the northern edge of the Papuan Fold Belt. The area is underlain by middle Miocene carbonate and fine grained clastic sediments intruded by late Miocene hornblende gabbros.Two mineral deposits occur to the south of Lake Kopiago. These are the Bisamu gold prospect and the Wunaki zinc-lead gossan.The Bisamu deposit consists of a calcic skarn assemblage which is geochemically anomalous in gold, silver, copper, zinc, cobalt, bismuth and tellurium. The prograde mineral assemblage includes garnet, clino-pyroxene and epidote whereas the retrograde assemblage includes epidote, quartz, actinolite and chlorite. Pyrrhotite is the dominant sulphide with minor pyrite and marcasite and trace chalcopyrite and sphalerite. Minor magnetite is also present. The Bisamu skarn shows many of the features typical of gold-skarn type mineral-isation.

Jan 1, 1994

By Worotnicki G, Tillmann V. H

Past experience with fully bonded cable dowels placed as a means of reinforcement in highly stressed crop pillars at the New Broken Hill Consolidated Limited (NBHC) mine indicated such support was not fully effective. Typically overbreak of the crown occurred leaving long lengths of cables hanging from the back stripped of grout and rock with the potential load carrying capacity of the cables not having been fully utilised. This mode of behaviour had been observed in the cable dowelled crowns of three longhole open stopes (EROS) mined to the No. 12 level at NBHC. A system of support with improved mechanism of load transfer from rock to cable and capable of full utilisation of cable strength was proposed for the crown pillars of future Stopes.

Jan 1, 1983