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Drum winders have now been built to attain depths of 3000 m and more in a single lift in accordance with the South African Code of Practice SABS 0294, which was introduced at the time of the last hoisting conference in 2000. Since then, this code has not only been followed for several winders in South Africa but was also followed in deep mines in Canada. Design of winders and their braking systems are described in the paper. Koepe winders are in use for high payloads of up to 50 t and to hoisting depths of around 2100 m. As known, the stress range of the hoisting ropes is the key parameter for rope fatigue. However, as per the SABS Code of Practice 0294, relying on static design is not the answer to the question of where the limits are for Koepe installation. The paper describes factors that are recognised to have influence in rope life and suggests definition of new design criteria for friction winders in order to get viable solutions for high-capacity hoisting from deep mines similar to drum hoisting.

Jan 1, 2005

The prevention of silicosis by metallic aluminium has been reported by Denny, Robson, and Irwin in two papers. The first was published in 1937; the second, in 1939. The results definitely established that silicosis was prevented in animals by the inhalation of small quantities of aluminium. The present communication records subsequent progress in this field of research.

Jan 1, 1944

Strata bolting/dowelling reinforcement techniques are being reintroduced into the mines of the National Coal Board. There are strong reasons for the selection of the full hole anchorage principle of bolting and for the development of the wood/resin dowel. There are strong reasons also for the measurement of strata bed separation as the method of assessing the effectiveness of a roof bolting system. There are several designs of bolts. Instruments have been developed for investigation and control purposes. Different drilling and bolting machines have been employed in trial sites. In addition comparative laboratory model work has been conducted on simple non-bolted and bolted systems.

Jan 1, 1971

Results from current NERDDC funded research into the geotechnology of highwall trench mining methods have clear implications for mine planners in the areas of blast design, trench shape, location of the surcharge spoil and remnant coal pillar design.Adoption of successful smooth wall blasting techniques not only removes safety hazards from the trench face, but limits development of bedding partings at the seam contacts that interrupt the smooth transition of stress across the coal seam.

Jan 1, 1992

By Evans A, Jones O

Surface subsidence resulting from "total extraction" of coal in the Collie Basin first occured in 1987 when Western Collieries Ltd trialled the Wongawilli mining method. Because very little quantitative subsidence data existed for the weak, Permian sediments, a research program was set up prior to the extraction of the first panel. The objective of the study was to be able to predict subsidence characteristics and effects prior to mining future total extraction panels. Attempts at predicting subsidence began using existing subsidence models from other coal mining regions, however, as more site information became available, it became clear that it was necessary to develop a separate, she specific predictive model for the Collie Coal Basin. Analysis of extensive field monitoring data for both surface and subsurface subsidence has produced a series of empirical models which can predict the shape of surface subsidence troughs and corresponding tilts, and strains for rectangular panels and describe the sequences of ground movement from the mine roof through to the ground surface.

Jan 1, 1992

By Williams RC

Overlying the coal deposits of the Sydney Basin are several lakes and other bodies of water. These include the Pacific Ocean, Lake Macquarie, the Tuggerah Lakes and the stored waters of the dams of the New South Wales Metropolitan Water Sewerage and Drainage Board. The coal beneath these bodies of water amounts to hundreds of millions of tons. Colliery workings have approached these areas of water and in some instances first 1"orkings of bord and pillar have taken place oi_eshh the water. he problem which now faces mine manage- and other interested authorities involves the determination of the maximum ;mount of coal which can be safely extracted from beneath the water. There are many factors to be considered including the depth of cover, seam thickness, geological details and strata movements.

Jan 1, 1972

By C F. Nichol, L Smith, R D. Beckie

A better understanding of the hydrogeology within mine waste rock and cover systems is essential for the quantification, prediction and prevention of metals loading to the environment surrounding waste rock piles. The effect of surface condition on the internal flow mechanisms within an intermediate-scale constructed waste rock pile is being investigated at the Cluff Lake Mine, Saskatchewan. Changes in the water balance, the outflow distribution and water residence time have been observed in the waste rock pile following successive modifications of the surface condition. The three year old, run of mine, free-dumped surface was ripped to a depth of 30 cm to 40 cm, and levelled in October of 2001. In August 2002, a 10 cm to 15 cm cover of compacted waste rock was placed on the pile. Outflow, precipitation and run-off data collected during natural and artificial rainfall events have been used to quantify the maximum infiltration rate, and the spatial pattern of discharge and cumulative volume of water that infiltrated into the waste rock under each surface condition. Infiltration data together with the outflow data provide a basis to address the residence time of water within waste rock and the dominant flow mechanisms for different surface conditions. With a free dump surface spatially distinct wetting fronts are observed at the base of the pile that vary in flow rate by an order of magnitude (measured at a 2 m by 2 m scale) and in time by up to a week. Following ripping and levelling, similar cumulative outflows were observed, but the magnitude and arrival time of wetting fronts changed across the pile. A decrease in outflow volume, a decrease in infiltration volume, a two-fold increase in the response time of wetting fronts and a more spatially uniform distribution was observed following placement of the compacted surface layer. Based on preliminary data, the internal structure appears to be the dominant factor controlling outflow variability.

Jan 1, 2003

By D Purdy, K Wilkinson, P Blake, M Fitzell, J McLellan, L Feltrin, O Dixon

The northern Drummond and Bowen basins region represents one of AustraliaÆs most prospective areas for epithermal vein and stockwork style gold deposits, with both low and high sulfidation epithermal mineralisation known in the region. 3D-GIS reconstructions, numerical and probabilistic modelling (UDEC, FLAC 3D and WofE) are used here to develop a better understanding of the controls operating on the mineral systems of the region and are aimed at enhancing predictive capabilities. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

The granitoid rocks in Burma can be subdivided into three main belts viz. (1) Eastern Granitoid Belt, (2) W-Sn related, Central Granitoid Belt and (3) Porphyry Cu (Au)-related, Western Granitoid Belt. The W-Sn related, central belt Granitoids were interpreted to have generated during the continent-arc collision and the Porphyry Cu(Au)-related, western grantioid belt was emplaced in a magmatic-volcanic arc above an east-dipping subduction zone. INTRODUCTION Major tectonic domains of Burma Burma region can be subdivided into N-S trending (6) major tectonic domains from west to east (1) Arakan Coastal Strip as ensimatic Foredeep (2) Indo-Burman Ranges as Outer Arc or Fore Arc (3) Western Inner-Burman Tertiary Basin as Inter-Arc Basin (4) Central Volcanic Belt (Central Volcanic Line) as Inner Magmatic-volcanic Arc (5) Eastern Inner-Burman Tertiary Basin as Back-Arc Basin and (6) Shan-Tennasserim Massif as ensialic, Sino-Burman Ranges (Bender, 1983). The Sagaing (transform) Fault and Shan Boundary Fault form as a tectonically significant boundary between Eastern-Burman Basin (Back-Arc Basin) and continental,

Jan 1, 1987

HIGHWALL MINING - DECISION TO MINEUlan had completed operations in the first Open Cut area due to high stripping ratios and the presence of geological features which destroyed a significant portion of the coal in the upper part of the seam. The pit had been abandoned in 1994 and operations had moved to a new location to the north west.

Jan 1, 1998

By Williams ID

Ore and coke of various size fractions (1 to 11 mm) were packed in a column (146 ó) and resistance to air flow measured under a range of conditions. Results have shown that layered charging results in an interface having essentially a directional structure the thickness of which is directly proportional to the coke and ore size ratio and whose flow resistance exceeds that of the coke layer many times its thickness. Friction factor - Reynolds number plots showed large positive departure from the Ergun equation for all components investigated whilst functional analysis and that in terms of bed constants, showed a strong dependency of the pressure gradient on bed properties and the actual particle size as well as the size ratio. It is also shown that pressure gradient in mixed beds follows previously reported behaviour and that a directional interface offers higher resistance to flow than a mixed interface having the same volumetric ore/coke ratio. Significance of results to practice is discussed.

Jan 1, 1975

By Takagi T, Seetharam R, Sie SH, Naito K

Tin-polymetallic vein type deposits are one of the major source of metal producers in the Circum Pacific Belt. This type of deposit is of great importance for the modem electronics and medical industries because of their high content of rare metals (especially indium and bismuth). We have studied two representatives, Tosham of India (Cu-In-Bi-Sn-W-Ag-Au), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), using proton and electron microprobes in order to delineate the distribution of medical/high-tech rare metals. The electron microprobe study showed that major indium carrier in such type of deposit are roquesite (CulnSZ), sphalerite, stannite and a Cu-Zn-Fe-In-Sn-S mineral; and that indium is incorporated in sulfides by coupled substitution like Cu + In = 2(Zn + Fe). The proton microprobe showed that indium at trace levels is also present in chalcopyrite and pyrite. In addition, zinc, copper, arsenic, antimony, selenium, tin, and bismuth are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are higher in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is genetically related to S-type magma, while the Mount Pleasant deposit is related to A-type granite. Tosham ore contains zinc-bearing biotites that coexist with chalcopyrite in ore bodies but Mount Pleasant ore lacks such biotite. We propose that the difference in elemental abundance between the two deposits are caused by the different character of source magma and different mineral associations of the ore body.

Jan 1, 1995

FOR some reason there is not any extensive literature in print on the electrolytic refining of copper, although the method is in general use in America and Europe. In Australia there are but three plants in existence one small one at Wallaroo, in SouthAustralia; one at Lithgow and one at Port Kembla the last two being in New South Wales. The largest of these is the Port Kembla plant. It is also the most modern, and embodies all the latest appliances and improvements of electrolytic practice.The plant and methods about to be described is that at Lithgow, with which the writer was associated for some years, and the experience gained there may be of interest. Electrolytic refining of copper is one of the simplest operations of metallurgy, but, like all metallurgical operations, it requires constant attention and a large amount of common sense. The man in charge should be endowed with an insatiable curiosity as to why certain things are occurring, and an instinct of cleanliness, whichmy first mentor in chemistry, Mr W A Dixon, once impressed on me was better than godliness.

Jan 1, 1911

By Khosia NK, Ravishankar SA, Sankar TAP

Alumina reduction in Rajhara iron ore slimes essentially involves separation of hematite from gibbsite in relatively coarser fraction and from kaolinite in the finer fraction. Selective dispersion flocculation studies on synthetic mixtures clearly indicated that while it was possible to achieve almost perfect separation of hematite from kaolinite using starch and PAMX (modified polyacrylamide containing hydroxamate functional groups) flocculants, no selectivity was observed in iron oxide-alumina system. A schematic flowsheet suggested on the basis of this work for the beneficiation of Indian ore slimes thus consists of classification in a hydrocyclone, followed by selective dispersion of coarse fraction (underflow) and selective flocculation of the overflow fraction. Starting with a feed assaying 46 per cent Fe and 11.6 per cent A1203, a concentrate assaying 60 per cent Fe and 4.7 per cent A1203 could be produced at an overall iron recovery of 60 per cent using conventional Reagents.

Jan 1, 1993

By Thomas L, Archibald N

The use of oxygen in the Mount Percy cyanidation circuit was investigated, with the aim of improving recovery. Preliminary batch and plant testwork justified a plant trial, and it was demonstrated that the use of oxygen reduced gold leachable from plant tailings by 12 per cent, and was economically viable. Oxygen is now in permanent use. Other benefits of oxygen in leaching were not proven. There were no savings on compressed air costs and no measurable reduction in cyanide consumption, although HCN levels in the atmosphere above the tanks declined. The possibility exists that more efficient use of compressed air for tank aeration could have achieved similar recovery gains.

Jan 1, 1992

By Jepsen L, Gifford M, Thomas G. S

Mine planning requires careful prediction of both the head grade and tonnage of mineralisation. As part of the planning process, operators of the Murrin Murrin nickel/cobalt orebodies (located in the Eastern Goldfields province of the Yilgarn

Jan 1, 1998

The specification for tender nominated the requirements for ore hoisting and servicing; this showed that one common duty winder could be selected. Foliowing the design of the shaft layout, the merits of fixed or rope guides were compared and the latter selected.The specification called for the supply and installation of the complete hoisting system. Construction of the winder tower and shaft bottom steel work had to proceed while mine development was in progress using the sinking winder and headframe. Guide ropes, winder ropes, and the sky shaft were installed in the shortest possible time, and as the shaft was not equipped with ladder-ways, a second means of access had to be provided.Very few problems were encountered witll the commissioning of the winder, and in the first 2 years of operation the only significant modification was to the circuitry associated witll the moving access platforms.Hoist rope tension checking and adjustment are simple, and non-destructive testing has shown no deterioration of these ropes. The operation of the balance ropes has been very satisfactory but cleaning presented problems in the early stages. Guide ropes have been trouble free and require minimum attention.Normal wear on the PVC rope groove inserts on the winder drum has been negligible.Since the commissioning on fully automatic ·control, the winder has operated with very few, minor delays.

Jan 1, 1969

Optimising drill performance has always been a primary goal of drilling and blasting managers. Improving drilling rates and utilisation will ultimately drive the cost per foot or metre downward. Additionally, more consistent production will ensure shovel or dragline performance goals are met and the chances of machine idle time is minimised. Over the past 20 years, many studies have examined rotary drilling factors and performance issues. In most cases a common theory points to energy input versus drilling output. Indexes such as specific energy and total work energy have been -developed to quantify the drilling process. As general engineering principles dictate, energy is required to drill rock by overcoming compressive and shear strengths. Concurrently, the greater the energy input, the faster the penetration output. Therefore, by examining the basic drilling energy parameters, optimisation is possible. The principles of rotary drilling are driven by five factors. When optimised individually and as a system, drill performance will improve. Most recent studies all agree that a performance relationship exists between bit load, bit rotation, and hole flushing. Additionally, proper bit selection and most of all, the operator, can have a tremendous effect on drill productivity. By analysing these factors and establishing the best case scenario, an overall drilling system can be engineered to match the mining characteristics. Furthermore, by balancing these factors, a lower cost will be achieved through increased production rates, maintenance costs, and effective drill utilisation.

Jan 1, 1995

By Mitchell I, Gelfi P, Dunne R, Pyper R

Dump leaching at Teller in its present form began in the fourth quarter of 1988 as an adjunct to milling operations. Initial plans called for a dedicated dump leach facility capable of processing ore at an annual rate of 2.0 million tonnes. Construction of a dump leach pad, collection and process ponds, carbon adsorption system, elution plant as well as reagent addition and ancillary facilities was initiated in mid-1988. During the course of construction, additional reserves were proven. As a result, design throughput was increased to 4.0 Mtpa. Leach pad capacity and solution supply systems were upgraded to handle the larger throughput. However, the carbon adsorption/elution facilities were not upgraded due to space limitations. During 1990 it was decided to expand the dump leach operation to 6.0 Mtpa. Construction of a second leach pad was required which was initiated in early-1991. Plans were again upgraded prior to completion to a target annual throughput of 10.0 million tonnes was. A further two leach pads have been constructed. The first of these being completed during the latter part of 1992. Construction of the latest and largest pad commenced early in 1994.

Jan 1, 1994

High pressure (-1.2 GPa) Early Cretaceous granulite facies orthogneisses in Fiordland, New Zealand are in tectonic contact with a cover sequence comprising mid-Palaeozoic amphibolite facies metasediments, subordinate metavolcanic rocks and syntectonic granitic orthogneisses. This cover sequence and the underlying granulites constitute upper and lower crustal plates of a mid-Cretaceous metamorphic core complex whose emplacement was linked to continental rifting and the Late Mesozoic breakup of the Pacific margin of Gondwana. Exhumation of the lower plate granulites occurred in two stages. The first stage was associated with extreme attenuationand tectonic denudation of the cover sequence accompanying emplacement of the core complex, leading to rapid uplift of the granulites but without generating the large volumes of Fiordland-derived sedimentary detritus normally expected if uplift and erosion were the only factors involved in unroofing the granulites. Final uplift and exposure of the granulites at the surface occurred mainly during the last 10 Ma in response to transpression across the mid-Tertiary Alpine Fault and/or the obduction of Fiordland continental crust over oceanic crust of the Tasman Sea.

Jan 1, 1990