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Taking the third meridian as the eastern boundary of proved payable auriferous country, there is a stretch of country, nearly 600 miles in width, in which no appreciable amount of gold has yet been discovered. Many prospectors have attempted to .penetrate or traverse it, but comparatively few have thought it worth while proceeding with the examination.The desolate stretch of waterless desert-the very few and insignificant outcrops through the sand and the almost total absence of feed for horses have, combined, presented such a barrier as to preclude prospecting. The few who have traversed the country are eloquent in denunciation, yet their investigations, necessarily hurried, are not quite satisfactory. The absence of water utterly debars a thorough examination being made. Gold may exist in quantity, yet it would have to be extraordinarily plentiful to render its obtaining profitable. Too fantastic is the idea of its ever being a mining district; shifting sand to traverse, utter absence of wood and water render the notion absurd. Likely looking belts occur, but these in all "cases are small and remote from water. Gold has been obtained from likely look ing quartz reefs, but only by fire assay, and then but a few do to the ton. Without wishing to be pessimistic, I would unhesitatingly declare that east of the third meridian, and between the parallels 25 and 30 degrees in West Australia, there is no gold in payable quantities.

Jan 1, 1901

By P L. McCarthy

To design and operate a successful mine the technical specialists must agree on what is ore, what is not ore, and how quickly the orebody is to be mined and processed. These seemingly simple questions defy easy analysis and can push mining engineers, geologists, metallurgists and others to the limit of their capabilities. The questions are rarely addressed adequately in feasibility studies or in operational planning. To optimise the mine and processing plant requires proper determination of cut-off grades or values, prediction of feed variability on an hourly, daily or longer basis, right-sizing the mining rate for optimum product quality, understanding the cost of capital and the expectations of investors, and many other considerations that involve geology, geotechnical engineering, mining, metallurgy, environmental effects and economics. This paper addresses the key matters that should be considered as inputs to the practical issues of metallurgical plant design and operation.CITATION:McCarthy, P L, 2015. Integrated mining and metallurgical planning and operation, in Proceedings MetPlant 2015, pp 35–45 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

WMC was a late entrant into Indonesia in mid-1996, but had considerable experience and success in exploring in Asia, particularly the Philippines since 1988. Given the geological similarities to the Philippines and IndonesiaÆs superior æcradle to graveÆ Contract of Work (CoW) tenure system, the entry into Indonesia was a logical decision but nonetheless a result of detailed planning. At the time of WMCÆs entry, Busang in Kalimantan was still a 60 moz wonder and the euphoria of this apparent discovery had overflowed into every aspect of exploration. Many junior mining companies and tenement speculators were clamouring for properties in Kalimantan, whilst other serious and capable explorers had to compete for properties and exploration personnel in an era of high and often unrealistic expectations. The picture in late-1998 and through 1999 is dramatically different, as the worldwide downturn in the price of most metals coincides with financial and social crises throughout most Asian countries. The impact of this has been particularly severe in Indonesia and when coupled with the negative sentiment of the Busang fraud has resulted in an exodus of junior companies and also some of the majors. This is understandable given the much publicised social unrest, uncertainty of government, mooted changes to the eighth generation CoW, increasing illegal mining and heightened community expectations. The reality however is somewhat different and although clearly a crisis in many respects, it is also a time of great opportunity.

Jan 1, 1999

By P Gunn, M Watts

The general goal of passive acid mine drainage (AMD) treatment is to reduce levels of acidity and metals to acceptable levels. Most treatment systems use either an oxidising or a reducing strategy. In oxidising systems, alkalinity is added along with dissolved oxygen; in reducing systems, dissolved oxygen is removed (if present) and then alkalinity is added. It is recommended that small-scale field trials be conducted as part of the methodology of selecting the best remediation strategy at AMD sites. Following successful field trials at the Sullivan Mine AMD, the Pike River Coal Company (PRCC) has shown foresight by using the same system to treat AMD generated as a result of taking a bulk sample of coal at the Pike River coal field. The system reduced acidity by 100 per cent, iron by 99 per cent, aluminium by 96 per cent, nickel by 95 per cent, manganese by 51 per cent and zinc by 99 per cent. The success of this field trial suggests that a system using a reducing strategy may be appropriate for the Pike River Adit AMD site.

Jan 1, 2005

By E Skinner, G Lane

Project delivery strategies are determined by project context, business case requirements, scale of project, market conditions, ownerÆs capability and preference, contractorÆs experience, resource and skill availability, project location and type of project or facility.Successful project management requires the setting of coherent, effective and realistic business objectives and success criteria. The management team needs to lead, prioritise, resource, align, plan, track and communicate the processes that enable the realisation of these business objectives and success criteria.For any given project there is a unique balance between selection of a simple project delivery strategy that minimises interfaces and a complex strategy that necessarily engages the use of expertise and experience from numerous parties. The right balance for a project between these "book-end cases" is a function of how the project owner or managing contractor defines its objectives and chooses to manage risk, cost, schedule and project quality, in the context of the conditions affecting the project.Selection of an effective project delivery strategy requires a detailed appreciation of the range of external and internal environmental / shaping factors which influence the project. These factors include the project constraints imposed by the business, market or operational environments and the selection of an effective mix of primary (head contract), secondary (mix of vertical and horizontal packages) and tertiary (type of individual contract) strategies. The selection of the primary, secondary and tertiary strategies also shapes the project, the size and responsibilities of the ownerÆs team and the framework for delivery of outcomes.How does an owner or prime contractor decide? What is the optimum for a given project? Those with operations management backgrounds will have different views to those with project and construction management backgrounds.Is the simplest practical approach the best approach? Each and every interface needs to be managed.The owner will want a very experienced team that is engaged directly with the owner. The team will have a track record of successfully performing projects using contractors skilled in their respective disciplines and selected using competitive tendering on brilliantly designed scopes of work and good contract terms, with a fully defined project scope and appropriate schedule, for which all significant risks have been addressed and no scope changes are outstanding. Budget and schedule will be expected to have been developed with a full understanding of the scope, situation, risk management requirements etc.The problem is that these conditions rarely exist. The challenge in selection of a project delivery strategy is to resolve how best to address the inadequacies between the ideal case and the present reality. The mechanism for addressing the inadequacies defines the likely outcome of the project.CITATION:Lane, G and Skinner, E, 2013. Project delivery, in Proceedings MetPlant 2013 , pp 50-65 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By Hemingway P, Boag J

Major operating aspects of the Mary Kathleen Uranium Ltd. treatment plant are discussed with partkular reference to those which are peculiar to this operation.Problems associated with the production of a penalty free uranium oxide product are examined and the methods developed to overcome them are described in detail.INTRODUCTIONMary K,athleen Uranium Ltd. is the largest of the Australian uranium producers. The flow-sheet is based on fine grinding, standard sulphuric acid leach, ion exchange concentration, and magnesia precipitation of the final product, with certain modifications introduced as the result of pilot plant investigations at the South Australian Department of Mines Research Laboratories in Adelaide.The plant commenced operations in June, 1958, attained design tonnlige of 1,120 tons per day in September of that year and has since operated continuously with a throughput in excess of 1,000 tons per day. Pilot plant recommendations generally have been followed, and predicted results have been attained. The only exception has been the silica and rare earth content of the product produced during the early months of operation. Considerable modification of the early resin regeneration techniques resulted in the reduction of the silica content of the product to within specification limits. Research work in the ion exchange section has also resulted in the reduction of the rare earth content of the product to below specification levels. All product now being produced is completely within the agreed specification limits of impurities.

Jan 1, 1961

SEVERAL serious accidents, which had occurred owing to the platman leaving the plat without first withdrawing the "chairs" from the shaft, set the writer scheming to devise a mechanically operated system which would obviate such accidents and be "fool-proof". It was obvious at the outset that some means of indicating to the engine-driver by the movement of the "chairs" themselves, whether they were "in" or "out" of the shaft, was necessary.An arrangement of signalling similar to railway semaphores was considered, but was rejected owing to the difficulties accruing from the large number of communicating wires which would be required down the shaft-viz., 2 for each level. After several experiments, a comparatively simple and efficient electrical system was devised, and which is covered by Commonwealth Patent TO. 10,402.One of the chief features of the apparatus is its simplicity, and its strongest point is the fact that both the engine-driver and platman receive visual indication of the position of the "chairs." The arrangement consists of a miniature coloured glow lamp, one for each level of each shaft compartment, arranged and placed beside the numbers and arrows corresponding to the various levels, on the winding engine indicators. Also a large indicating glow lamp is installed at each compartment in the various levels, in proximity to the levers for operating the "chairs." Upon operating the various levers for the "chairs," an electrical current...

Jan 1, 1909

The mining industry is generally regarded as a high risk industry, mainly because of the difficulties in estimating the tonnage and grade of mineral resources, the fluctuations in metal prices, mining problems and other problems which occur with mining in offshore and remote locations, such as appropriation or disruption to supply. As a consequence, finance providers require a high reward from mining projects. In the past two decades, the development of "mega" projects has led to the packaging of the finance becoming more sophisticated. Some would see this move as a measure of the evolution of banking rather than an intrinsic facet of mining finance itself. Project financial managers now require a thorough knowledge of all the financial tools which are available and have to be aware of the funding options so that they can put together a finance package which minimises the cost of the financing with the risk spread adequately between the partners of the financing. The different sources and types of finance for mining projects are described herein along with the factors which determine their costs. To understand the ramifications of financing mining projects, it is essential to appreciate the fundamental difference between debt and equity, which illustrates the importance of gearing. Costs of finance are determined by the interaction of supply and demand forces. Bankers and other financiers have become more adept at isolating a wide selection of risk elements and have devised a formidable range of insurance mechanisms. There is still a lot of money looking for good project risks and if a good project is properly presented and structured, financing can be obtained in today's market.

Jan 1, 1990

By A. J. MOORE

When the writer first saw the square-set timbering, he was at once impressed with the fact that the frames made by the sets, along the lode and across it, were composed of panels with rectangular openings, and it was puzzling to understand howsuch a collapsible construction could resist pressure that came unevenly on it. Later he learnt that the sets did not satisfactorily resist such pressure, but mullock filling had, to a great extent, to undertake this duty for them. So it appeared that the setswere practically an expensive scaffolding, enabling the miners to work in the face and carry the stope forward, till the filling was put in behind them to take the pressure of the roof and sides of the excavation. Of course some of the pressure is takenby the sets, but this is because "the set timbers prevent the filling being done perfectly; if it were practicable to remove the sets before filling, the filling by itself would more effectively support the back and wall, than do the combined sets andmullock. On the whole, therefore, the sets can hardly be said to be of much benefit where pressure has to be resisted. Despite this, the system has been of immense service in mining wide lodes, but for all that, it can only be pronounced a makeshift.This is no reflection on Deidesheimer, the famous originator of the square set, for, as will be shown later on, this way of...

Jan 1, 1912

By D Craw, C Smith, C Rufaut

Oceana Gold (NZ) LtdÆs, Macraes Gold Operation currently has two tailings impoundments, the larger of which covers approximately 75 ha. When an impoundment is temporarily out of use, the surface dries and dust can be blown from the surface to the surrounding area. At present water spraying is used to stabilise the surface, but this is not ideal as Macraes mine can experience water shortages during the summer. This paper examines an alternative method of surface stabilisation using vegetation as a ground cover. The tailings have a low natural fertility, so it is important to determine what will actually grow in the tailings, and whether amendments are necessary. Also important is the effect of the amendments on arsenic mobility in the tailings as the schist rock at Macraes has naturally elevated levels of arsenic. Three plants species, rye corn, barley, and lupin, were grown in metre-deep lysimeters at Macraes mine site. The plants were grown in unaltered tailings, and tailings with one of two amendments added: Bioboost (an organic fertiliser containing biosolids), and superphosphate fertiliser. The leachate from each lysimeter was collected and analysed monthly to determine the extent of arsenic mobility. In addition, laboratory experiments were set up to determine arsenic mobility in tailings with amendments at the centimetre scale.   All plants grew best with the fertiliser amendment, with rye corn growing the best overall. Plants growing in unaltered tailings either barely survived (rye corn, barley) or died (lupin). Plants in the Bioboost amended tailings grew only slightly better than in the unamended tailings. Laboratory experiments indicate that the addition of phosphate fertiliser greatly increases arsenic leaching at the centimetre scale when compared to unamended tailings. The addition of Bioboost only marginally increases arsenic leaching, compared to unamended tailings. This trend has not been repeated in the lysimeter trials on the metre scale over four months. Current results suggest that of the plant types trialed and amendments used, rye corn with superphosphate is the most practical short-term tailings stabilisation method at Macraes.

Jan 1, 2004

THE following notes, compiled in the first instance for the makers of rock-drIlls, were read by Mr. Hanton at a meeting of the Broken Hill Branch on 12th Septelnber, 1922. It was decided that all Broken Hill mines be asked to give their individual views on the subject, so that a comprehensive Broken Hill view could be published. Replies have been received from four (4), mines to date, and their'ideas fairly well coincide with those set out by Mr. Hapton. His notes were as follow:- "The Zinc Corporation Limited.NOTES ON ROCK-DRILL DEVELOPMENTSAs far as our present experience goes, the rock-drill developments on this mine will probably be something resembling the following. The programme is subject to modification or alteratian, according to circumstances. The results of further trials and improvements in present drills, and the design of new types, will, of course, affect any general scheme such as that outlined. It appears reasonably certain that the 3i-in. reciprocating drills which have done practically all the stoping up to date, will be gradually replaced by hammer drills of the internal water-feed type, and that the existing types of hammer drill on the mine will be converted into internal water-feed machines instead of being used as dry machine with outside jet.The ultimate types of machines will be four... Type 1 would be a machine equivalent to the Ingersoll Leyner: 248, Waugh Turbro, SullivaIi DX61, or Holman CH2. This would be used for driving, cross-cutting, and similar excavating work, and possiblyfor stoping also, and should be capable of efficiently working any class of ground. Features, apart from the general requirements set out later, would be the weight of the machine and mounting height of the machine above the seating (as this affects the convenience of boring back or bottom holes); absence of projections on the mounting which the air hose will foul as the machine is fed...

Jan 1, 1923

The Hyde Macraes Shear Zone (HMSZ) is an extensive low angle semibrittle mineralised structure in the Otago Schist Belt, New Zealand. The shear zone is located on the lower limb of a late metamorphic recumbent fold. Structural observations suggests that the shear zone initiated as a high strain mylonite zone and transgressed the ductile/brittle boundary (D4) later in its development. A surge zone at Round Hill is bounded to the south by a NE-SW striking lateral ramp which displaces the hanging wall shear (HWS) by 50 m. Oblique strike slip displacement during surge zone propagation created space for deposition of the sheeted vein complex or stockwork. Quartz recrystallisation in stockwork veins suggests that the veins were deformed in a ductile manner and implies that surge zone propagation may have occurred during late D3 deformation. A macroantiform was produced during D3/D4 shortening below the HWS. Over tightening of the antiform hinge created SW and NE-dipping ramp thrusts. Continued strike slip displacement along the lateral ramp rotated the antiform and associated ramps into a south plunging drag fold. Post-mineralisation (D5) structures include NE-dipping nonna! faults below the HWS and SW-dipping low angle imbricate thrusts above the HWS. The development of these structures was kinematically compatible with normal movement on the HMSZ and is related to mid Cretaceous break up of Gondwanaland in the SW Pacific.

Jan 1, 1992

The geologist is often called upon to give judgment on the possibilities of reviving a former mining field presumably worked out as far as the evidence then available indicated. From time to time, scarcity and consequent high prices of metals has led to there-examination of many old fields. The possibility of resuming investigation on them where the practical miner ceased work, even where he had the aid of the trained geologist, has long since disappeared.Means of access to mines have been removed and water fills the workings. Hence an indirect mode of attack becomes essential.This method depends mainly on past history, and may be described as a reaching out by faith supported by shrewd guessing from the known to the unknown. Apart from whatever general intelligent observations may be made in situ of the evidence of former mining activity, the method depends largely on the examination of the past history of the field as revealed in the official records, company reports, plans of underground workings, local newspaper accounts, and the testimony of practical miners formerly employedon the field, the' reliability of which has to be carefully sifted. The matter derived from the examination of these sources must next be rigorously collated and correlated where possible. When the review of all individu!1l features and aspects has been completed, tentative and speculative conclusions may be drawn which, though not verifiable before the event, will usually prove to be more serviceable guides in exploratory operations than mere "blind stabbing."As an actual illustration of what is involved in the mode of procedure outlined above, the following is the description of an investigation in which the writer took part.In 1937, during the course of the Commonwealth Aerial, Geological and Geophysical Survey of Northern Australia, a detailed geological investigation was undertaken of the Croydon gold field, situated near the south-eastern. extremity of the Gulf of Carpentaria in North Queensland.The history of the field briefly is as follows: It was discovered in 1885, reached its peak of production 1896, declining thereafter till 1906, when operations ceased. The total production was about 1,000,000 ounces of gold bullion, containing approximately 40 per cent. of silver. The gold bullion was won from flat-dipping quartz reefs, which yielded an average of 2.oz. to the ton, and the maximum depth to which production occurred was 500 feet. Subsequent prospecting below this depth failed to locate further ore.In consequence of the inaccessibility of the mines and the almost total masking of the' surface by alluvium, the investigation of future possibilities became largely an. office ,study, which was conducted under the following headings:-1. Recording of factual data of each mine separately.

Jan 1, 1950

By R Bertuzzi

This paper presents a three-dimensional analysis of a trapezoidal-shaped segmental tunnel lining for a recent tunnelling project in Sydney. Two- dimensional analyses, hand calculations and equipment selection defined the lining geometry and loads. The analysis, which was undertaken using 3DEC (Itasca), included a complete ring of six segments bolted together to assess the impact of imperfectly built rings. Asymmetry was induced in the analysis by unfavourable positioning of segments within construction tolerances. Model output includes displacement and stress within the entire ring and normal, shear and bending moments at the joints. For the case analysed, the results suggest a 10 mm construction tolerance increases normal and shear stresses along the radial joints by approximately 25 per cent and 15 per cent, respectively and up to a doubling of the induced moments.

Jan 1, 2008

IN concentrating mills, where several millerals are recovered for realisation in more than one product, various systems are used to express the relative economic value of the work done, and, in the hope that it may prove of use to other operators, the writer will describe a system which, in his opinion, is more complete than any other that he has seen published.The controlling factor in all mill work must be based on the economic result represented by the greatest margin possible between the realizable value of the products and the cost of obtaining same.From a mill-man's point of view these are affected by the following factors:1. Metal contents of ore.2. Grade of products.3. Recoveries.4. Working costs.The grade of ore milled is usually outside the mill-man's control, but this may exercise a considerable influence on the grade of his products, metal recoveries, and revenue per ton of ore. Higher grades or recoveries may be obtained by using a more expensive process, or by additional grinding or reagents, and the economic comparison can only be arrived at by obtaining an analysis showing the monetary value of each variation within the possible limits.In the system to be described, the value of unit variations of metal contents of the ore, grade of products and recoveries are calculated in terms of a monetary unit per ton of ore with the returning charges ruling, and any suitable metal prices. To do this it is necessary to assume what, for convenience, is termed a "standard" set of results from the mill, preferably representing about average conditions, and having calculated the effect of unit...

Jan 1, 1931

By G Akdogan, R V. R Handfield-Jones

The application of microwave energy as a substitute for conventional heating has drawn interest from many researchers in extractive metallurgy. Microwaves have a heating effect just as many other forms of radiant energy. Microwaves are able to penetrate the substance at which they are directed and in being absorbed heat the material from the inside. As a result of heat generated in the interior of a particle, microwaves can affect the rupture of a particle (in this case a host ore) and break down the matrix of the particle (host ore) and expose the recoverable mineral to the leaching reagent. Two series of leaching experiments were carried out at temperatures above 90????C using a conventional heater (hot plate) and a modified 850 W, 2.45 Ghz microwave oven. One series of tests was carried out at ambient temperature. A pyritic/arsenopyritic gold concentrate was leached with 3.3 kg/t to 6.8 kg/t NaCN for two hours. The extraction of gold at 6.8 kg/t NaCN was higher in microwave assisted leaching (59 per cent) than the extraction obtained in leaching at conventional heating (39 per cent) and ambient temperature (28 per cent). Extraction of gold was dependent on the size fraction used and was 48 per cent for û75 ¦m, 43 per cent for û90+75 ¦m and 37 per cent for û150 + 90 ¦m size ranges.

Jan 1, 2000

Research and Tests on Improving the Technology of Enrichment of the Copper-Molybdenum Ore

Sep 13, 2010

Tonnage and grade are the principal reported components of mineral resource estimates but tonnage is a derivative of two more fundamental estimates; volume and bulk density. Typically, most of the effort in a resource estimation study is directed towards grade and volume, yet poor application of bulk density data to resource models can result in significant biases. The impact on tonnage estimates is easily recognised but poor density estimates may also introduce subtle biases into the grade estimates. Methods for measuring bulk density have been discussed previously. This paper focuses on the manipulation of bulk density data and the extension of bulk density from essentially point measurements to block estimates within resource models. Bulk density is a continuous, geologically controlled, spatial variable and should be treated as such. Issues such as combining data from multiple sources, sample support and the interdependence of bulk density and grade estimates must be resolved. The statistical and geostatistical techniques used for grade estimation are, under the right circumstances, equally applicable to bulk density. The importance of bulk density needs to be recognised. With robust raw data and correct estimation procedures, better estimates of bulk density can be obtained and both local and global tonnage and grade estimates can be improved.

Jan 1, 2000

Of the world's total production of gold the largest proportion comes from the more regularly consistent ore bodies, but in the aggregate an important part comes from those which are often irregular, uncertain and small. These smaller ore bodies are often high in grade and, as the capital required to work them is not large, they appeal to people seeking a quick and profitable return for a small outlay.These small mining concerns cannot afford detailed geological and petrological investigations and mapping, so they are very often dependent on local knowledge and experience which admittedly may be of really great value.Nevertheless the absence of skilled guidance may not only cause good opportunities for intelligent exploration to be lost, but discourage the seach for other ore bodies.lVIining engineers in the course of their travels in the examination of mines often come across such cases and also others where problems of finding lost ore bodies have been solved by the man on the spot. As records of cases are valuable and useful additions to the knowledge of ore occurrences, the writer now proposes to describe one such case coming under his observation in recent years.It is that of a small mine, known as the Idaho, at the southern end of the famous "Golden Mile" at Kalgoorlie (see Fig. 1). This mine has been a small and very erratic producer ever since it was abandoned by an English company which owned it forty years ago. Except for one period of four years it has always been owned and worked by parties of co-operative miners and during its time has gone through a tortuous career. Although it has often...

Jan 1, 1938

Low displacement fault zones often comprise a mesh of interlinked faults, extensional-shear and purely extensional 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 through going faults. Mesh formation generally involves hydrofracturing (Pf > s3, at least locally) and the condition Pf ~ s3 to be maintained for the mesh to remain a high permeability conduit, requiring fluid over pressuring 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. Fluid redistribution in the crust is influenced by maximum hydraulic gradient (not necessarily vertical), by existing permeability anisotropy arising from bedding and other forms of crustal layering, and by structural permeability developed under the prevailing stress field. Strong directional permeability develops in the s2 direction, parallel to fault-fracture intersections within the mesh and orthogonal to fault slip vectors. In particular tectonic settings, stress-controlled permeability allows strongly focused flow through fault-fracture meshes with high potential for mineralisation. Favoured localities for mesh development include short-lived link structures along large-displacement fault zones such as dilational jogs, lateral ramps, and transfer faults.

Jan 1, 1995