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By Roden S

This paper illustrates that sampling problems and difficulties are as common in an R&D environment as they are in an operating plant. Researchers need to be aware of the potential influence of poor sampling practices and when feasible determine the sampling and analytical precision at the start of any experimentation. Specific problems that have been encountered are discussed and the procedures implemented to overcome these difficulties are described. Examples from projects include the cyanidation of a Au/Ag ore, column leaching of refractory gold and oxide ores, the bioremediation of contaminated sites and the flotation of ore containing native copper.

Jan 1, 1976

IA )W cli',hla cn1cnt fault 7011(-s 0 11Cn cOrnprise a nrc,II of inrcIIinkc(I faults, cvtcnqonal shear and In]rck cxtcnsir>nal vein- fractures. Hydrothermal mineralisation localised around such structures testifies to their importance as conduits for fluid flow. Mesh structures are most commonly developed in situations approximating bulk pure shear but predominantly simple shear meshes also occur. They appear to develop through the infiltration of pressurised fluids into a heterogeneous rock mass with varying material properties. In some circumstances, mesh formation appears to be a precursor to the development of major throughgoing faults. Mesh formation generally involves hydrofracturing (Pf> a3, at least locally) and the condition Pf - 63 to be maintained for the mesh to remain a high permeability conduit, requiring fluid overpressuring at other than shallow depths in extensional-transtensional regimes. The volumetric character of earthquake swarm activity appears to result from the passage of hydrothermal fluids through mesh structures, representing a form of distributed fault-valve action along suprahydrostatic hydraulic gradients arising from magmatic intrusion, compaction overpressuring, metamorphic dewatering, etc.

Jan 1, 1995

By W Ilahi

Underground metalliferous mining methods often result in the formation of vertical openings to facilitate the extraction of orebodies. These development and production techniques can result in the creation of vertical open voids, which include stopes, orepasses, ventilation raises and other excavations. There are risks associated with the use of mobile plant in the vicinity of these voids, especially during backfilling and when bunds are constructed at the edge of a stope or void. These voids can present unacceptable risks if not adequately managed.

May 5, 2022

By McAllister J

Oxygen was in restricted use at Port Kembla until tonnage oxygen became available for steelmaking in the open hearth furnaces. In adopting the new process various modifications to furnace design and operation were necessary and some of these, including increase in roof height and variation in firing and draft control, are discussed.The design of oxygen lances is also discussed and various steelmakingtechniques considered.Steel production increased with oxygen roof lancing-one- furnace producing 8,507 tons in one week-but new problems, such as rate of refractory wear, and disposal of fumes, were created.Design of future open hearth oxygen furnaces is predicted.INTRODUCTIONIn the post-war era, the availability of "tonnage" oxygen caused a major revolution in steelmaking techniques. Various pneumatic processes showed that steel can be madeat a very fast rate and that oxygen steelmaking can be applied to open hearth furnaces. Methods used are surface impingement with roof lances, bath injection with door lances, flame enrichment with fuel firing, mixed gas and oxygen firing, and enrichment of normal combustion air by oxygen injection into the flue systems.Owing to its previous restricted availability and high cost, oxygen was used in rather small quantities in the open hearth furnaces at Australian Iron and Steel Pty. Ltd.(A.I. & S.), Port Kembla, until about the middle of 1960.At that time tonnage oxygen became available and roof lancing commenced on No. 33 furnace at No. 2' open hearth shop.

Jan 1, 1962

By Quadrio J. S, MacHunter A. M W

The initial development fl6tation testwork on Mt. Windarra op was completed on composited drill core intersections at the.Australian Mineral Development Laboratory. An exploratory winze provided samples, from the 130 M. level of the Mt. Windarra mine, for pilot plant and bench development tests. A limited test programme was initiated on the South Windarra drill core composites. Detailed mineralogy has been completed on selected samples from both ore deposits.

Jan 1, 1973

By Polthier K

A short discussion of the salient aspects of a dispersed flow model in relation to the gas flow in blast furnaces is given. The use of the theory in assessing vessel performance is mentioned. Tracer results of a blast furnace (688 m3) from three furnace levels and different radial positions are analysed and results presented as D/ud values. The significance of the shapes of experimental tracer curves are included and comparison is made with results obtained on other furnaces.

Jan 1, 1975

By Winter W, Steele DA, Trudu AG, Gray CM

The Luzon arc extends for about 900 km from Taiwan to the island of Mindoro (central Philippines); in this area late Tertiary to Recent volcanism is considered to be the result of eastward subduction along the Manila Trench. The arc is composed of five segments, all of which have individual characteristics with respect to tectonic setting and magma chemistry (Defant et al., 1989). From the north to the south these are (Fig. 1): (1) the eastern Coast Ranges of Taiwan and the islands Lan-Hsu and Lu-Tao (Taiwan Segment), (2) the islands off the north coast of Luzon (Babuyan Segment), (3) the Northern Luzon Segment, (4) the Bataan Segment, and (5) the Mindoro Segment. Defant et al. (1988) suggest that the Bataan and Mindoro segments of the arc, both of which are characterized by different isotopic compositions and levels of large ion lithophile element (LILE) enrichment in the lavas, are separated by a 'pull-apart' zone, the Macolod Corridor.We are currently studying the mineralogy and petrochemistry of Late-Miocene to Pliocene volcanism in the Northern Luzon Segment (NLS), which comprises the geographic area of the Cordillera Central. This area has so far received limited attention, inspite of its wealth of porphyry copper, skarn and epithermal gold deposits. In this contribution we report the first results of our study of igneous rocks from the Mankayan Mineral District (MMD) which is located in the centre of the arc segment under consideration.

Jan 1, 1990

During the 1960s chalcocite ore was mined from the Black Rock open cut. A large amount of this uneconomic material was not treated by the No 3 Concentrator at the time and as a consequence a surface stockpile was created which contained 750 000 tonnes of material at an average of 1.5 per cent copper.Laboratory trials indicated that due to oxidation, an average of 25 per cent of the copper was water soluble and the remaining copper was leachable using a sulphate/ferriclbacterial leach. On the basis of these trials it was decided to investigate the feasibility of producing copper via a leach SX-EW process. The investigation proved the process was feasible, so began the design, construction and commissioning of a 10 tpd (cathode copper) Copper Leach SX-EW Pilot Plant. CMPS Pty Limited in a joint venture with John Holland Engineering Pty Limited were awarded the turnkey contract for the design, construction and commissioning of the Pilot Plant.

Jan 1, 1993

In the future, Illawarra Coal, the primary metallurgical coal producer in the southern coal fields of New South Wales, will face many unique challenges not found in other coal or minerals production areas. To manage these challenges and determine the best strategy for the business, Illawarra Coal has adopted a systematic strategic planning process, which starts from the broadest possible options analysis and culminates in a ægo-forwardÆ operating case that individual mine sites use as the basis for short-term planning. This paper will discuss two major topics. Firstly an overview of the Illawarra Coal and BHP Billiton strategic planning processes. This will demonstrate the range of variables and inputs that are required for the planning process, and the system which is followed to evaluate different alternatives for the extraction of the resource. Secondly, having discussed the primary external and internal factors that must be accounted for in the planning process, and the main issues affecting the viability and likelihood of each alternative, the paper will discuss the particular challenges that Illawarra Coal will face in the coming decades. These challenges include: market and price uncertainty; managing impact on surface features, infrastructure and environment; community interaction; transport and logistics constraints; unknown mining environments; lack of geological knowledge; limited surface access for new mining domains; changing attitudes to longwall mining in the Illawarra; ageing workforce; and cost and overhead management. The paper intends to discuss how these issues impact the business currently and how they are incorporated into Life of Asset plans and overall corporate strategy for Illawarra Coal.

Jan 1, 2007

In underground ore mining of copper ore, lead-zinc ore, tin ore and fluorspare in German Democratic Republic geological situation is characterized by ore deposits of small thickness and great variability of ore grades and mining conditions. For long range mining strategy and short-term planning of production a model was developed fitting to make optimal economic mining decisions. Starting point of the model is a cost function representing all direct costs per unit recoverable metal in concentrate for each stoping unit (ore reserve block). In the costs function the results of regression analysis of ore grade and metal recovery in concentration plant were considered. All stoping units (ore reserve blocks) of a mine were arranged to growing direct costs. The relationships of recoverable metal, ore tonnages and corresponding costs were plotted in a diagram. The data processed by- computer and the graphic representation of the results make possible 1. economic evaluation of stopes and ore reserve blocks, 2. estimation of cut off grade, 3. optimization of works planning.

Jan 1, 1977

By G Munro

he Melbourne City Link project will complete a missing link between two existing major freeways in the Melbourne road network, providing a much needed bypass of the Central Business District for through traffic. The project, which is being financed under a BOOT arrangement with the Victorian State Government, involves the upgrading of significant stretches of existing freeway and the construction of new sections involving viaducts and tunnels. The tunnel sections, which are the focus of this paper, are beneath residential and business areas, the Yarra River, the Royal Botanic Gardens and significant sporting facilities where surface construction would be either impossible or unacceptable (reference Figure 1). The shorter, 1.62 km west bound Domain tunnel comprises two cut and cover sections through Olympic Park then the Yarra River, the driven section of 0.68 km length and exits through a common cut and cover section with the east bound tunnel under St Kilda Road and Sturt Street. The longer 3.76 km east bound tunnel commences at the common portal, through cut and cover under St Kilda Road then 2.86 km of driven section before exiting at a cut and cover section at Burnley. The longer Burnley tunnel has an access and ventilation shaft at approximately its mid point.

Jan 1, 1999

Hindered settling devices (teeter bed, up-current) are widely used in the mining industry to classify mineral streams into various size fractions and to separate minerals. In the coal industry these devices are extremely successful in separating coal of low densities from shale and pyrite. In the beach sand and in the iron ore industry, this equipment is used to beneficiate minerals either as stand alone units or lately as classifiers in spiral circuits. The challenge that these applications give to metallurgists is to be able to simulate the equipment by using mathematical models with or without the aid of small bench scale tests. In any green fields and many brownfields projects, limited amounts of samples make pilot plant tests difficult. Although there are mathematical approaches available, the accuracy is of such a nature that it can not be used for design purposes. This refers to the use of StrokeÆs law, NewtonÆs and the so called intermediate law as is widely published. Research done by the author indicates that in most applications none of the above laws apply. Using the original data as published by Perry and Chilton (Chemical Engineering Handbook, pp 5-64, 1973) and re-plotting it indicates that the settling velocity of particles is a function of (particle diameter)n where n varies between 1.2 and 1.6 which is different from that predicted by the intermediate law that suggests that n = 1.18. Another way of describing the relationship between the drag force and the Reynolds number is done by iterating between settling velocity and the Reynolds number. This needs more computer time but the accuracy obtained from this does add value to simulations. A small but simple test is suggested to determine the settling velocity of particles to enable metallurgists to determine variations from the theoretical calculations to determine the influence of viscosity and particle shape.

Jan 1, 2008

By Dudgeon RN, Houston ML

When the original Mount Gunson joint venture,between CSR Limited and United Uranium N.L. ceased operations in December 1971, an intensive exploration campaign was launched to prospect for more ore in the Mount Gunson region. This campaign resulted in the dis- covery'of the Cattle Grid copper deposit. A comprehensive sampling pro- gramme including the sinking of over 200 diamond drill holes and two vertical shafts,proved the existence of 4.6 million tonnes of ore, at a mean grade of 2.4% Cu,calculated at 1.00% Cu cutoff.

Jan 1, 1975

Water is an integral and essential part of mining business. Two issues crucial in the management of this resource, scarcity and excess, are increasing awareness of the importance of water and changing the value perceptions of the industry because they affect both the existence and continuation of the business. Therefore its value should be reflected in the water management that is practised on site. Historically water in mining has been perceived to be of low value so management practices have not been good or well implemented. Political and social transformation in South Africa has been accompanied by the promulgation of new legislation. South African water law is now underpinned by Integrated Water Resource Management (IWRM) principles. It impacts water pricing, provides for water pollution charges, prioritises water users, has specific mining and water related components and requires water licensing as part of the licence to mine. Mining no longer has a priority on water resources and has to compete with other water users to gain access to resources. New institutional arrangements are being put in place to implement the regulations. All this requires a paradigm shift in miningÆs view of water. Generally the sector is still catching up with the new requirements, principles and philosophies. However, the way in which South African mining values water is changing. This is demonstrated in partnerships between the industry and other water users. These partnerships are Integrated Water Resource Management (IWRM) in practice and they achieve sustainable development goals. These partnerships are essential for mining to stay in business, expand operational capacity, reduce impacts, prevent legal action and reduce reputational risks.

Jan 1, 2006

By D J. Brake

Faced with the need to improve workplace conditions in both its development and production headings in its existing K1 orebody, as well as its new K Link and K2 orebodies, the Kencana mine in Indonesia took the novel approach of reversing the ventilation on most of its access ramp by outcasting up the ramp to the portal. Working levels were then fed with fresh air via auxiliary fans sealed into the current surface ‘egress’ intake raises (ladderways) or another small surface intake raisebore rather than from fans hung in the ramp as in the past. Outcasting the portal provided a substantial increase in the total mine exhaust capacity allowing fewer levels to be ventilated in series and significantly improving conditions, especially in the most difficult workplaces to ventilate. It also reduced the consequences if there was to be a fire on a vehicle in the ramp. The same system using the ramp as an exhaust is also intended to be used as part of the final ventilation solution for the new K2 orebody which also uses a novel single surface ventilation shaft that is vertically split into separate intake and exhaust compartments using a concrete brattice. Using the main ramp as an exhaust has potential application in many other operations in Australia using surface ramps which otherwise frequently suffer from overuse of series ventilation circuits and poor working conditions at the mine bottom.

Mar 21, 2011

By M A. Mular, T Akroyd

A fundamental model, which considers the subprocesses of particle collection by bubbles in flotation, is applied to two comprehensive flotation surveys in the rougher stages of C3 concentrator, PT Freeport Indonesia. The flotation surveys focused on the collection of: cell-by-cell and size-by-size metallurgical, cell hydrodynamic, and pulp and surface chemistry information.The two surveys were conducted at significantly different feed tonnages, giving rise to significantly different feed particle size distributions, pulp densities and mean pulp residence times. A series of model simulations are performed with the aim of quantifying changes in copper recovery, on both a size-by-size and unsized basis, with changes in values of the hydrodynamic parameters and hydrophobicity of the copper sulfide mineral. This was carried out in an effort to identify the most promising route to increase overall copper recovery in roughing. It was found that by increasing the hydrophobicity of the copper sulfide mineral surfaces it became possible to optimise cell hydrodynamics, which targeted increased fine (-12 ¦m) copper sulfide mineral recovery but without adversely affecting coarse (+150 ¦m) copper sulfide mineral recovery.

Jan 1, 2007

The experiments described in this paper were carried out as a preliminary to a comprehensive study of the factors which affect the behaviour of lead during and subsequent to deformation by rolling and pressing. These observations are therefore to be considered as introductory to a further paper dealing more specifically with the above-mentioned variables.EXPERIMENTALThe rolling was carried out in a small mill with six-inch diameter surface ground rolls, both of which were electrically driven at 15 r.p.m. The average draft per pass approximated 0·03 in. The pressing was performed between platens in the compression unit of a 30-ton Amsler machine. The flat faces used had a ground finish comparable with the surface of the rolls. All hardness measurements were made with a Herbert "dead load" Brinell machine. The following te'sting conditions were maintained: ball diameter-5 mm.; load-10 kgms.; duration of loading-30 seconds; temperature of testing-16 to 18°C. The hardness values which are given are the mean of two or more impressions made at corresponding positions on the test specimens.PREVIOUS WORKSince the researches of Tresca (1):j: into the nature of the plastic flow of metals during various forging and extrusion...

Jan 1, 1939

A company tax rate based on profitability return, or as more commonly expressed, a resource rent taxation scheme has been intro- duced at various stages in the past by both Australian state and commonwealth governments. At present a number of overseas countries are applying this form of legislation to the taxing of sections of their mining industries. Within this study, ways in which this type of tax has been used are examined. The form in which the tax can be applied varies. 1. It can be selectively or universally applied. 2. The base on which economic return is calculated can be selected in a number of ways. 3. It can start operating only when high profit levels exist, or alternatively be the basis of a total taxation scheme. The implication for the Australian mining industry of the introduction of different types of resource rent taxation schemes is assessed within the context of previously enacted systems.

Jan 1, 1978

By A F. Cooper

The northeast-southwest trending ~25 km2 area incorporating Bald Hill is located 18 km northeast of Haast, and 5 - 7 km west of the Alpine Fault in South Westland, New Zealand. The geology consists of Greenland Group greywacke overlain by a Cretaceous-Tertiary sedimentary sequence and fluvio-glacial/marine terrace deposits of Quaternary age. Alluvial gold in Cole Creek, draining west from the summit of Bald Hill, may be derived either from vein mineralisation in basement rocks or from fluvial or marine terraces.   This paper focuses on the potential for in situ gold and base-metal mineralisation in sporadic, siderite-rich quartz veins that cut basement greenschist facies metasediments that have been overprinted by contact metamorphism.   Throughout the area, vein compositions are dominated by quartz and commonly feature zoned plagioclase. Alteration adjacent to veining within the contact aureole is dominated by 1 - 2 mm, coarse grained biotite, with small amounts of sulphide, and is pervaded by abundant siderite veinlets. Outside the aureole, wall rock alteration to veins consists of fine grained chlorite. Trace element XRF analysis has been used to ascertain base metal concentrations within samples of vein and alteration zones collected from throughout the area. Vein and alteration zone mineral assemblages containing <5 per cent sulphide, with low concentrations of As, Cu, Pb and Zn indicate low potential for gold and base-metal mineralisation in the Bald Hill region. Contact metamorphism of Greenland Group basement in the northeast of the region, is likely due to emplacement of a poorly exposed Cr- and Ni- enriched gabbro. The presence of biotite and andalusite in hornfelses indicate contact metamorphism occurred at temperatures >350¦C and at depths <10 km. Widespread vein distribution does not appear to be related to contact metamorphism or gabbro emplacement. Further research is required in order to establish the fluid source from which the veins were precipitated.

Jan 1, 2007

Early in 1930 William S. Robinson, Managing Director of Zinc Corporation Ltd., anticipated a rise in the price of gold and a devaluation of the Australian currency. 'WS', as Robinson was known, formed a.syndicate in London, which later became incor- porated as Gold Mines of Australia Limited (GMA) to invest in gold mining properties in Australia. GMA examined many prospects and subsequently undertook the development of several mines in eastern Australia. The syndicate also held a number of options and several large reservations for gold exploration in Western Australia over which it was proposed to carry out an aerial survey and thorough scien- tific assessment. To do this Western Mining Corporation Limited (WMC) was incorporated in Melbourne on the 2nd March 1933. The founding chairman of WMC and GMA was the highly respected `Collins House' figure, Sir Colin Fraser. The aerial survey was carried out, and a group of eminent geol- ogists from Harvard University examined many prospects and identified several which warranted development. To finance these activities `WS' formed Gold Exploration and Finance Co. of Aus- tralia Ltd. (GEFCA), in London in July 1934. GEFCA ultimately held 95% of WMC and 62% of GMA. The finance came mostly from London based South African mining companies which had been subscribers to his earlier syndicate plus some American inves- tors. (The Group Structure in 1936 is shown in Appendix `B").

Jan 1, 1988