Search Documents

Cook Colliery currently mines in the Argo Seam, beneath old workings in an overlying seam. The Argo seam is up to 4.8 m thick and a continuous haulage system behind an ABM25 is used to develop first workings. Current partial secondary extraction utilises floor stripping and pocketing or sumping first working pillars on retreat. The following paper summarises this recent secondary extraction experience, particularly from a geotechnical perspective, but also considering production and ventilation issues. Outcomes and learnings are presented for mining in this challenging and close multi-seam environment. The sealed castor seam workings are within 20 m, and vary from unmined areas to large first working pillars, to partial extraction panels and full extraction panels. High stress remnant pillars and goaf-edges are notable mining considerations. The mining environment is further complicated by faulting, thrust zones and weak laminated roof.

Nov 25, 2010

Development of Underground Gold Processing Plants Underground gold processing plants have potential advantages over traditional surface installations related to a smaller environmental footprint, reduced capital and mining costs, improved security and increased value of the product delivered to surface. The concept of processing gold ores on the surface is the traditional paradigm. A process of pre-concentration of ore underground is likely to result in a major shift in operating costs. In particular, run of mine ore or a large proportion of it will not need to be transported to the surface. As a result, environmental and financial benefits are likely. Underground plants are likely to be pre-concentration systems where the process product is a high-grade concentrate and tailings for stope backfill. Units will be either static or modular. Concentration methods will be gravity and/or flotation or leach based. This paper discusses the development underground gold plants from early concept, through to the world's first operational unit, a newly commissioned unit and the technical basis of a fully modular system.

Sep 13, 2010

The objective of a mine planning exercise is to plan a safe mine that maximises net present value (NPV) for the project. Two primary elements are key to design of a mine plan optimised to maximise profit: selection of an optimised production rate and selection of an optimised equipment fleet. Both depend upon accurate estimations of capital and operating costs for the equipment and for the life cycle of the mining operation. Once a trial production rate is determined, a primary equipment fleet, ie excavators, haulers, and blasthole drills, can be determined based on material characteristics and haulage distances and gradients. An auxiliary fleet, dozers, road maintainers, service trucks, etc can be determined using less rigid productivity criteria. With an equipment fleet determined, operating and support personnel can be assigned based on shift requirements and equipment operating needs; and material and supply requirements can be estimated. Knowing the areal dimensions of the major equipment items, road widths and repair shop dimensions can be determined. Personnel numbers and supply requirements determine the square metre sizes of offices, change rooms, and storage facilities. Reliable sources of capital and operating unit prices and costs for all these items are referenced in the paper. Once preliminary capital and operating cost estimates are calculated by applying unit costs to equipment, personnel, material and supply needs, potential profit can be tested using DCF techniques. An optimised mine plan can then be determined by testing the potential profitability of multiple mine production rates. Because of the economies of scale, full capital and operating cost estimates must be completed for each production rate in order to produce meaningful comparisons.

Dec 6, 2010

Planning for the Macraes Extension project highlighted the need for additional tailings storage availability. The possible solution of developing new tailings impoundments in Northern Gully, in tum, led to concerns being expressed by the regUlatory authority over the assimilative capacity of Deepdell Creek. Philosophical differences over the appropriateness of applying a seepage model used to set standards in consents for the original project resulted in the company re-evaluating the whole monitoring system associated with tailings disposal and seepage control. Re-evaluation indicated problems arising from the existing in-stream water quality monitoring in respect of protection of the aquatic ecological system and verifiability of results. A new monitoring system was designed relocating the compliance monitoring point out of the stream and into the gully containing the tailings impoundments giving greater certainty of monitoring results to all parties and providing improved protection for the aquatic ecology of Deepdell Creek.

Jan 1, 1993

Rational decision making is generally perceived by managers of operations to be a delicate process of committing large sums of money and putting other people's life at risk. Consequently most managers may argue that the decision process requires good judgement, intuition and extreme caution; and not one easily made through the use of fancy mathematical algorithms and computer programs. The advent of artificial intelligence and expert systems in the computer industry combined with recent technological innovations in mathematical and economic problem solving is sure to change this perception. PARETO OPTIMALITY is an economic and a mathematical optimisation concept applied to solving real life operational problems; and one that the current volatile economic forces would require managers to employ because it is virtually real. REALISMM is a computer software package developed using the principles of Pareto optimality, dynamic programming, optimal clustering of information and decision maker interaction to generate decision maker preferred solutions. REALISMM has scope for artificial intelligence and expert systems application for cases where the decision maker is unsure about his objective preferences.

Jan 1, 1993

New Zealand has been a significant producer of gold for over a century. Total recorded production is over 850 tonnes. There were three major periods of production: the first and biggest was between 1860 and 1880, the second was between 1895 and 1920 and the third was between 1930 and 1945. After 1945 gold production fell continually until 1980 when the major upward adjustment in gold price led to renewed interest. There have been important new developments in each of the known gold-rich areas: Westland, Otago and Coromandel and exploration for gold in these areas and in previously unprospected regions has reached unprecedented levels.

Jan 1, 1988

ABSTRACTMechanised cut and fill stoping in the Racecourse orebodies between II and 9 levels was started in 1964.Five stopes are in progress over the two level interval, extracting the full strike length (600-2,000 ft) of each orebody without transverse pillars.Each stope is served by a central 10 ft by 12 ft service intake ventilation raise and an 8 ft by 8 ft return air raise at each end of the stope. Each stope is divided into two sections for drilling. firing. mucking, and fillingto maintain steady production. All equipment is kept in the stope for one level lift stoping. Gardner-Denver 2 boom jumbos are used for uphole drilling and Wagner ST 5 Scooptrams for loading and transport to ore passes located in the footwall of the orebody. A Wagner PTIO is used for materials handling and scaling of the stope backs.Mill tailings, after one stage of cycloning are used to fill the stope, one section at a time. About 80 per cent of the water is removed by decantation while the remainder percolates through hessian-covered pipes and boxes.The ore is passed to 11 level where it is hauled by the 3 ft 6 in. gauge train to the tipple at the shaft area. The ore is crushed underground before hoisting to the surface.A performance of about 100 ton/manshift is achieved by the drilling, blasting, and mucking crews in the stopes.

Jan 1, 1968

By Taylor R. G

This paper reports a biogeochemical study of the Siberia lode of the Herberton tin field. Soil near the orebody contained high levels of Fe, Cu, Pb, Sn, As, Mld Mn. Polycarpaea spirostylis and Indigofera dominii were associated with these high levels but several other species apparently could not tolerate them. The potential of these species as indicator plants is discussed.

Jan 1, 1975

By Zwaan J, Kepa J

Ok Tedi mine has become one of the major copper producers in the world. In the process of becoming of age, it overcame the challenges of operating in a locality which is young in geological terms, experiences very high rainfall and has a topography which gives rise to frequent landslides. This paper discusses some of the geological, mine and geotechnical engin- eering aspects of the Mt Fubilan ore deposit.

Jan 1, 1991

(Published by courtesy of the Great Boulder Pty. Gold Mines, Limited)1. INTRODUCTIONThe faults described in the following paper are of a somewhat unusual character, and have presented a serious problem both in the development and mining of many ore-bodies on the Eastern side of the Boulder Belt. They are mentioned only briefly in the literature of the field, but were observed by, both Stillwell (1)t and Gustafson (2), and have been studied by other geologists and operators in various parts of the "Belt." Their effect on the lodes of Hamilton Section, Great Boulder Mine, was described by King (3) in 1937, and, during recent years, they have been encountered in most of the Great Boulder workings extending east of the Boulder Dyke.Although this paper is based mainly on a study of faulting and development problems on the Great Boulder mine, the general conclusions reached may be applicable to the solution of similar faulting problems in other mines throughout the field.In order to arrive at a clear understanding of the somewhat complicated relationships which the east-dipping faults bear to the lode systems it will be necessary to give a brief outline of the salient geological and structural features of the "Belt" before proceeding to describe the faults themselves.2. GENERAL GEOLOGYThe most recent descriptions of the geology of Kalgoorlie are those by Stillwell (1) and Gustafson (2) and the reader is referred to these as representing the basis of current knowledge of the geology of the field.The Boulder Belt is comprised of a central core of altered quartz dolerite which is flanked on either side by fine grained greenstones and lavas, usually referred to as the calc schists. Down the centre of the quartz dolerite mass there is an infolded bed of slate (2, p. 105) which has been intruded in lit par lit fashion by albite porphyry; the composite body of slate and porphyry so formed is known as the "Boulder Dyke." Numerous smaller porphyry dykes intrude both the quartz dolerite and the calc schist; these vary in composition and range from chloritised hornblende porphyrites to albite porphyries.The whole of the rock assemblage has been subjected tG a considerable amount of folding, faulting, shearing and fracturing, the greater part of which took place before the formation of the lodes.

Jan 1, 1941

A pyrite flotation concentrate assaying 0·065 oz/ton gold was investigated to determine the mode of occurrence of the gold. Ftom cyanidation and acid leaching experiments it was concluded that O· 02-0· 03 oz/ton goldwas in solid solution in pyrite and the balance of the gold was finely dispersed as grains throughout the pyrite.Autoradiography and electron-probe examination of possible areas in briquetted concentrate did not detect any grains of gold. Neutron irradiation and gamma spectrometry confirmed on 100 mg samples the fire assays obtained on 1 assay ton samples.Oxidation to hematite and reduction to magnetite at 600°C made practically the whole of the gold extractable by cyanide. This technique could be of major significance for gold ores which contain a substantial amount of "refractory" gold.

Jan 1, 1969

By T Salles, G Duclaux, E R. Ramanaidou

In a continental environment, sediment mobilisation, dispersion and deposition are mainly controlled by mass gravity and streamflow processes. Alluvial sedimentary systems have an important economic value because of their capacity to host mineral resources. In the Hamersley Province, alluvial iron deposits (including the well-known detrital iron deposits and channel iron deposits) play an increasing role on the commodity market. Alluvial deposits exploration is challenging and generally involves geomorphologic and stratigraphic field studies, as well as expensive exploratory surface sampling and drilling. We applied a new surface processes modelling technique to investigate iron rich material, ie the erosion product of bedded iron formations -dispersion in the Hamersley Province. LECODE is a 3D-parallel surface processes forward modelling code designed to compute surface flow and solve erosion, transport and sedimentation on the geological time scale. The code offers new quantitative ways to better understand how sedimentary deposits develop in intra-continental and channel environments. Here we show that our integrated forward model is capable of opening a window to the construction of sedimentary architectures, including facies distribution, deposit thickness and development of heterogeneities such as mineral traps over the modelled domain. The model results represent 1 Ma of surface evolution and are validated through comparison to published paleovalleys map and known occurrences of iron ore deposits. This numerical modelling approach allows for the first time to track alluvial materials from source to sink through time, test existing geological models and faithfully reproduce the first order distribution of alluvial iron deposits in an area of interest. This work strongly suggests the presence of iron rich alluvial deposits reserves under cover, in unexplored detrital fans in the Fortescue Valley. This method, potentially coupled with sediment geochemistry and basin analyses studies, has the potential to maximise alluvial iron deposits exploration success, while reducing exploration cost and associated environmental impact.CITATION:Duclaux, G, Salles, T and Ramanaidou, E R, 2013. Alluvial iron deposits exploration using surface processes modelling - a case study in the Hamersley Province (Western Australia), in Proceedings Iron Ore 2013 , pp 75-80 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

Rhyolitic rocks are volumetrically significant in the eastern part of the Coromandel gold province, yet deposits hosted by rhyolite (Kapowai, Broken Hills, Neavesville, Wharekirauponga and Waihi Beach) are generally low grade and subeconomic, especially compared with andesite-hosted deposits. In contrast, rhyolitic volcanic centres in Nevada host a number of economically significant epithermal gold deposits such as Round Mountain, Sleeper and Bullfrog. The Nevada deposits are associated with 27-20 Ma continental arc volcanics dominated by ignimbrites (eg Round Mountain), or younger 17-9 Ma bimodal rhyolite-basalt volcanism related to extensional basin-and-range tectonics (eg Sleeper). The Round Mountain deposit is localised on a caldera boundary fault and the mineralisation was deposited soon after eruption of the host rhyodacitic ignimbrite. In other Nevada deposits, hydrothermal systems are linked to the closing stages of flow-dome complexes and mineralisation is localised along normal faults associated with extensional basin-and-range tectonism. The style and composition of the mineralisation is similar in both the Coromandel and Nevada deposits and consists of sheeted and stockwork quartz veins, containing electrum as the main ore mineral and only minor sulphides (mainly pyrite) Likewise, the vein minerals were deposited from low salinity hydrothermal fluids in the temperature range of 200-270¦C. Both the Neavesville and Round Mountain deposits are geochemically anomalous in molybdenum. The deep oxidation of the Nevada gold deposits, dry climate and low level of competing land uses combine to make it economic to mine and process very low grade ore (0.2 - 2.0 g/t Au) by heap-leaching with cyanide solutions in most areas of Nevada. Although extensive low grade gold mineralisation is known at deposits such as Wharekirauponga and Neavesville, it is sub-economic because of shallow oxidation and land use conditions that are unfavourable for open pit mining and heap leaching.

Jan 1, 1996

Ore sorting is a high capacity, low cost method of pre concentrating ores and in some cases of producing a marketable concentrate. In most cases it is applied to run of mine material, immediately after primary crushing and screening in sizes ranging from 10 mm to 150 mm. Recent developments in bulk sorting of friable uranium deposits have resulted in machines capable of handling fine materials with sensing and separation being achieved on a zone by zone basis. Modern ore sorting machines rely on the synchronous operation of four internal subsystems, feed presentation, sensing, data processing and separation. A variety of different sub systems is available which can be combined in various forms to produce sorters capable of handling a wide variety of mineral types. The benefits in using ore sorting cover a wide range of situations and are applicable to both established mines as well as new mining ventures. Reduced operating costs, increased productivity, capital savings, energy and resource conservation and environmental issues are all part of the reason why ore sorting is finding rapid acceptance in today's mining industry. The suitability of different ore types for pre-concentration using anyone of the variety of ore sorting systems can be quickly established using computer based techniques which require only small samples of the materials under investigation.

Jan 1, 1980

A pilot steel ladle injection facility designed to assist in the production of high quality steels suitable for use in pipelines has been built and commissioned at the Basic Oxygen Steelmaking (BOS) plant at Port Kembla Works.The plant design and the injection procedure are described.The performance of the unit and some metallurgical results are discussed in terms of the addition to the steel ladle of various quantities of calcium silicide and a lime based material. The effects of these additions on sulphur content and inclusion morphology and hence on steel ductility are also presented. The influence of ladle lining on desulphurisation is illustrated.On the basis of the experience gathered in the pilot plant a permanent and more sophisticated injection facility has been designed.

Jan 1, 1983

THE successful establishment of iron blast-furnace plants at Newcastle and Lithgow naturally invites attention to the economic utilization of the various products and by-products arising out of the industry.The general similarity in composition between Portland cement and iron blast-furnace slag very early attracted attention both in, the cement and iron-smelting industries. Probably the first use made of blast-furnace slag in the cementindustry was not of an honourable nature-viz, to use an almost worthless and cumbersome by-product as a not readily detectable adulterant in Portland cement, which was at that time very costly to manufacture.The astonishing discovery was made that in many cases the adulterated cement was stronger than the original unadulterated article. It was found that chilled blast-furnace slag introduced in moderate quantity and finely ground with the cement clinkerdid not injure, but usually improved, the quality of the resulting cement. This mode of, manufacture is recognized, especially in Germany, as a legitimate branch of the cement making industry.The use of slag for the manufacture of both slag cement and Portland cement has assumed very large proportions heth in USA and Europe so much so that in the former country plants not well situated and equipped for cheaply making cement from clay and limestone are being forced to close down. Slags from other than iron blast-furnaces, together with some of the latter, are not suitable for cement-making. All slags which disintegrate and fall into powder are wholly unfitted for cementmaking.Those highly charged with mineral oxide compounds...

Jan 1, 1918

Alluvial gold grades are typically highly erratic. It is very often difficult to establish with confidence the in situ grades of reserve blocks due to the small number of pit or drill hole samples available, and their erratic values. Trends in grade are often obscure. Geostatical methods are inappropriate due to the extreme nugget effect found in alluvial gold field data. Classical statistics appear more suited to such data but require assumptions to be made regarding the nature of the population sampled. Recent developments in computer intensive non-parametric statistical methods provide a new approach to dealing with some of the above problems. These methods avoid making assumptions about the type of population distribution, usually through some kind of re-sampling scheme. The bootstrap procedure involves taking the estimate of interest and synthesising its population of by re-sampling the original data a large number of times (1000+), at random and with replacement. The synthetic population is then used to draw conclusions about the likely behaviour of the true population.

Jan 1, 1985

By D Skinner, P Haeussler, D Bradley, A Christie

Mesothermal gold deposits of southernAlaska and Westland, New Zealand have both formed at the seaward edge of major collisional zones in the Pacific basin. In Alaska, production of large fluid volumes correlates in time with the addition of heat into the lower parts of the accreted terranes in the late stages of collisional orogeny. This heat was critical for driving both the metamorphic reactions that released the large volumes of fluid that carried the gold, and the contemporaneous widespread anatexis and magmatism. In Alaska's Chugach terrane, this heat as produced by subduction of a spreading ridge beneath the North America continental margin in the Eocene. The resulting products were the S-type granites and gold-bearing veins. The similar widespread S-type plutonism and gold veining in Westland's Buller terrane suggest that a similar tectonic event could have triggered ore formation along the southeastern edge of Gondwanaland. Based on the Alaskan model, a Devonian or Early Carboniferous age is favoured for high volume metamorphogenic fluid generation and gold vein formation in Westland.

Jan 1, 1995

An account is given of experimental apparatus for generating a short duration high velocity water jet and the effect of its impingement on various rock samples under air or water cover. The penetration was found to be highly dependent upon the rock structure; in general material with closely interlocking grains was resistant.The damage sustained by a stationary sample held close to the jet did not vary greatly whether the sample was in air or confined under a water layer; but when the sample was translated under the jet there was a marked increase in the damage sustained.Some consideration was given to the possible practical application of a water jet for deep hole drilling and an estimate made of the power requirements and transmission losses for such a system.

Jan 1, 1969

By F Pirajno

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. China’s mineral deposits are the result of metallogenic processes associated with the geodynamic evolution of tectonic plates and eventual amalgamation into their modern configuration. The principal tectonic provinces of China comprise the North China Craton, Yangtze Craton, Cathaysia Craton, Tarim block, Altay-Tianshan-Hinggan orogens (part of the Central Asian Orogenic Bel), Central China orogens, Songpan-Ganze orogen and Alpine-Himalayan fold belts, which are part of the huge Tethysides. These tectonic elements are testimony to a complex geological history spanning more than 3000 million years. This contribution will focus on selected areas of the Altay-Tianshan, the fold belts surrounding the North China Craton and Yangtze Craton and the mineral systems along the Ailaoshan-Red River fault zone. Mineral deposits in these provinces include gold, copper, molybdenum, tin, antimony, nickel, platinum group elements, lead and zinc.CITATION:Pirajno, F, 2015. Metallogeny and related tectonic settings in China , in Proceedings PACRIM 2015 Congress, pp 17–24 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015