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An investigation was made into the mineralogical characteristics of the upper portions of the 650 and 750 copper lodes. The investigation was based on a comprehensive suite of geological specimens representing all types of mineralization encountered during mining until the end of 1954 and the chief aims of the investigation were to determine (a) the minerals present and their textures and associations, (b) the paragenetic sequence of deposition of minerals in the orebodies, (c) significant changes, if any, which could be found in the orebodies with depth, and (d) the nature and mode of occurrence of nickel in the ore. The general structure of the orebodies is outlined and their mineral composition given. 10 textures exhibited by the ore minerals are described and a paragenetic sequence of events in the formation of the copper orebodies is outlined. No decrease in the complexity of the sulphide mineral textures with depth could be seen and no evidence was found to suggest that the tenor of the ore would decrease with depth although some factors which may eventually limit the extent of the orebodies are noted. The mode of occurrence of minor elements in the orebodies is described. Notes on the occurrence of pyrite, aikinite and berthierite in the orebodies is given and the orebodies are considered to be identified with LiIidgren's mesothermal type of sulphide ore deposit in which considerable replacement of older by younger generations of sulphide minerals occurred.INTRODUCTIONA mineragraphic study was made by Stillwell and Edwards (1945) of a suite of specimens submitted by Mount Isa Mines Limited from the Mount Isa Black Star copper orebodies with a view to determining 1. the nature, extent and association of arsenic, antimonyand bismuth minerals, 2. the mode of occurrence of silver and 3. whether galena and sphalerite occurred in minute forms and below the sizes readily observed in hand specimens.

Jan 1, 1961

By J E. Lynch

The Mt Leyshon gold deposit produced in excess of three million ounces of gold and considerable silver over a period of approximately 130 years. Most of this production occurred between 1987 and 2001. Mining commenced in 1872, however it was highly likely that Chinese miners were not only removing alluvial gold from the area but were also mining very rich æreefÆ gold. Records for early alluvial and hard rock mining do not exist, however gold production was probably considerable. In the early 1980s Marathon Petroleum (Australia) Ltd (MPAL) joint ventured into the Mt Leyshon area which had been held as a mining lease by Noranda Australia Ltd since 1968. Noranda at that time was concentrating its exploration effort on the Balcooma base metal prospect areas to the north of Charters Towers. In early 1982 MPALs parent company was taken over by US Steel. This led to an opportunity for MPALs Australian management to purchase all tenements and licences (except for coal, oil and gas) which were duly purchased for $US 1 million. At this time MPAL had a remarkable array of gold tenements (many of which were subsequently mined by other companies) and Mt Leyshon was considered to be the highlight. Early æseedÆ capital ($A 3.1 million) was raised with backers being the Bank of America, the NSW Government Superannuation Scheme, Westpac, private individuals and a Queensland grocery chain by the name of æJack the SlasherÆ.

Jan 1, 2004

The Coal Corporation of New Zealand Ltd (CoalCorp) is the largest coal producer in New Zealand, with extensive properties in both the North and South Islands. CoalCorp's North Island operations are kilcmetres to the south of Auckland. opencasts, are located in the catchment wildlife, historical and scenic values. in this catchment is the single most mining operations. centred on Huntly, a town some 80 Five coal mines, four of which are of Lake Waahi, a lake with significant The discharges of mine lodgement water important environmental constraint on Throughout New Zealand the use of water is controlled by a statute called the Water and Soil Conservation Act 1967. All industrial water users are required to hold Water Rights, which are in effect licences to take, use, dam, divert or discharge water. Water Rights are obtained through a legally defined process and any potentially affected party has the per to object to their granting. A special tribunal hears the evidence for and against an application, and issues its decision, which is reviewable in a higher court on Appeal. Rights, if granted, are issued subject to conditions and, in the case of mining discharges, limits would be set on flaw rate, suspended solids concentrations, turbidity, pH and the concentrations of any potential toxicants. This paper presents a case study of an integrated, catchment wide water management plan for Lake Waahi, that was prepared by the author, and others while the author was in the employ of CoalCorp, and its predecessor, State Coal Mines. The author is grateful to CoalCorp for their permission to submit this paper.

Jan 1, 1988

The coastline is. an incomparable stretch of sea coast known as Ninety Mile Beach. Two gas pipelines and two oil pipelines carrying hydrocarbons from thb'Bass Strait fields to the markets of Australia cross this beach. They cannot be seen as they are laid in trenching stretch- ing many miles out to sea and the beach was restored to its natural state. Even where the dunes were disturbed, suitable grass was sown thus consolidating the sand and preventing erosion. Ninety Mile Beach is but one of the many key.wildlife and recreational areas that our operations must be concerned with. Others include Westernport and Corner Inlet, but the one discussed in this paper in particular is the platform area of the Bass Strait itself. Never was the old adage "an ounce of prevention is worth a pound of cure" more meaningful than in offshore oil production. All are well aware of some of the events of the past several years that resulted in large and costly oil spills. Far less is known, seen or publicised about the measures and developments that are undertaken to ensure that such events do not occur. We also have well developed plans for response in the event of an emergency situation, which can be initiated with great rapidity. Our responsibility is to ensure that with the best of engineering technology and operating procedures, spills do not occur.

Jan 1, 1971

By J Ranford, A Harris, K Laughton

The Angas Zinc Mine (Angas) is a poly-metallic, underground mine in the Adelaide Hills that has been developed through arguably one of the most volatile financial time periods in living memory. From boom times during the commencement of the project, the global financial crisis (GFC) through the stabilisation of the operating period and then a subdued capital market for the period where mine life extension was targeted, the financial environment has always presented a different set of challenges. Indeed even the Underground Operators’ Conferences that have been held across the span of the project allude to these changes: ‘Boom and Beyond’, Launceston (2008); ‘Safe, Innovative and Sustainable’, Canberra (2011) and ‘Managing the Margin’ in Adelaide (2014).Angas gives a rare opportunity to see the entire life-of-mine of a project and its economic performance within a relatively short time frame. Angas, owned and operated by Terramin Australia Ltd (Terramin), will have undergone resource estimation drill out, feasibility study, permitting, commissioning, operating and completion and rehabilitation all within a period of approximately ten years. A number of sensitivities of the project were tested, particularly in the bankable feasibility study (BFS) stage and the aim of this paper is to identify the factors that impacted the operations profitability the most, whether they were identified preproduction or not. The key sensitivities assessed in the BFS were typical of similar studies, including operating costs, metal recoveries, capital costs, zinc prices, lead prices and exchange rates. The manner in which these sensitivities presented themselves in real life were not as anticipated and modelled in the feasibility study and were also heavily impacted by technical challenges.CITATION:Harris, A, Laughton, K and Ranford, J, 2014. Feasibility to mine completion – the real impacts on project economics, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 99–110 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By Godresse M, Turczynski G. P J, Driver I. J, Low G, Ozawa N

Geological evaluations of coal deposits have been traditionally undertaken in a somewhat manual manner. Information is collected downhole by chip sampling, coring and using downhole geophysical logging. This information is then interpreted by an experienced geologist to define the coal and noncoal lithological units. Coal units were subsequently correlated to provide data for structural modelling. In recent years a number of advancements in interpretation techniques have been made based on Artificial Intelligence. This paper describes an integrated geological interpretation system based on maximised use of Al techniques. The first part describes the lithological interpretation which uses a number of boreholes with both logged lithology and downhole geophysical logs. This information provides a learning set of data to the neural network. The second part concentrates on the correlation of both coal and noncoal units from borehole to borehole. Problems in this area, in a manual sense, are interpretation of correlation across weathering zones and other geological anomolies. The technique is based on pattern recognition and dynamic programming techniques where a correlation matrix is developed relating all holes with their maximum correlations.

Jan 1, 1995

The Central Extended Orebody is located within the Cracow Goldfield approximately 360 km northwest of Brisbane and approximately 220 km west of Bundaberg. It is an epithermal gold deposit hosted by the Late Carboniferous to Early Permian Camboon Andesite. The lode was mined by open cut methods and produced 170 458 tonnes of ore at 5.62 g/t gold.The geology of the rit is relatively simple, comprising two rock types, trachyandesite and rhyolite which have been sub-divided into several units. The trachyandesite is sub-divided into three rock types: brecciated trachyandesite which is the most widespread, hydraulically fractured trachyandesite hosts the mineralisation and the third sub-unit is chloritised hydraulically fractured trachyandesite and has no associated mineralisation. The mineralisation is confined to quartz veins in hydraulically fractured trachyandesite. Several phases of brecciation and subsequent quartz and quartz/adularia vein injection are evident although not all phases are mineralised. Two rhyolite dykes intrude the trachyandesite one is monolithic, the other is sub-divided into hydraulically fractured rhyolite (barren), silicified rhyolite and auto-brecciated rhyolite.

Jan 1, 1993

By Sulanto J, Talonen T

In the mid 1960's Outokumpu considered building a lead Flash Smelter on the basis of Flash Smelting technology developed first in the late 1940s for smelting copper concentrates. Pilot scale tests were carried out and the process was found technically sound. The project was however not economically viable under Finnish conditions and it was cancelled. In 1981 pilot plant tests were restarted after many enquiries from the primary lead producers. All the know-how and development made in copper and nickel smelters was applied to the Lead Flash Smelting process and the tests were successful. Outokumpu has so far tested several types of lead concentrate with lead contents ranging from 28 to 75 per cent. The concentrate is oxidized and smelted to metallic lead and slag directly in the Flash Smelting Furnace using high oxygen enrichment of tonnage oxygen. Fossile fuel is used in the Flash Smelting Furnace in cases when the feed material does not contain enough latent heat to smelt the furnace products even though pure oxygen is used for oxidation. Thus the process results in a low consumption of extraneous energy. Use of oxygen results in a small gas flow but it is rich in sulphur dioxide. The gas treatment facilities and sulphur recovery plant will be small in size and low in investment cost. The process is flexible and can produce stable quality of products from different types of raw materials. Quality of lead bullion especially the sulphur content can be regulated over wide a range, from 0.1 per cent upwards according to the needs of the refinery.

Jan 1, 1984

FaulIing west of the Mount Isa mine is described and is shown to be related to three groups of folds that have been recognized in the area. The first period of faulting postdates the first generation folding; these faulIs are regional faults (tectonic discontinuities) which are folded by second generation folds. The faulting accompanying the second generation folding divides the area west of the Mount Isa mine into four structurally and metamorphically identifiable blocks. The most prominent of these second generation faults is the Mount Isa Fault, which is characterized by a number of distinct zones of intense second generation folding and the presence of localized layers of mylonite. Only limited evidence for brittle deformation has been observed and the major movement appears to be associated with the plastic deformation of the rocks. Confined to the areas of second generation folding in the Mount Isa Fault are numerous third generation kink folds. A detailed description of the Mount Isa and other faulIs is presented together with evidence for their existence. The displacement accompanying this faulting cannot be established because of the complexity of the structure.Postdating these faults and all the folding of the area are minor cross faults.

Jan 1, 1973

In the current climate, there is a real need to bridge the gap between theory and the real world mining considerations, and develop viable, cost-effective, high performance thickeners. With a greater need to extract profits from both difficult-to-process ores and lower grade orebodies, coupled with the necessity to produce 'greener', less water intensive technologies, suppliers need to take current thickener designs to the next level and into the 21st century. The complexity of 'getting it right' within a thickenerÆs feedwell, the 'nerve centre' of the thickener, is no small task. Delivering dilution water and mixing this water with incoming feed slurry, addition of flocculant, maximising flocculant-slurry interaction to build aggregate size, minimising unabsorbed flocculant percentage, volume average of solids volume fraction, momentum dissipation ratio, dilution recycle ratio, volume average shear, maximum shear rate at exit, aggregate size on exit, uniform discharge profile and more ù all of these need to occur in the right order and in the right proportions within the feedwell. This paper discusses the genesis and evolution of a new feedwell design, the first major innovation in the thickening industry in over 15 years.

Jan 1, 2008

By Lang SC

The Broken River Province, in the northern part of the Tasman Orogen, is divided into the Camel Creek and Graveyard Creek Subprovinces. In the Late Cambrian to Early Ordovician, and again in the Late Ordovician, the northern part of the Tasman Orogen was probably a convergent margin with calc-alkaline volcanism. These episodes may have been separated by a passive phase in which quartz-rich flysch and tholeiitic volcanic rocks were deposited. Subsequently, in the Silurian, the region underwent extension forming a large turbidite basin which included the Camel Creek Subprovince and the Hodgkinson Province to the north. Melange is pervasive in the Camel Creek Subprovince which was folded twice in the Devonian. The melange may be related to thrusting accompanying D1. No rocks younger than Early Devonian have been recognised whereas, in the Hodgkinson Province, deposition continued until the latest Devonian. The Graveyard Creek Subprovince formed adjacent to the Camel Creek Subprovince, probably as a pull-apart basin on stable crust. The deformation history of the Graveyard Creek Subprovince contrasts markedly with that of both the Hodgkinson Province and Camel Creek Subprovince. In the Graveyard Creek Subprovince, melange is only present in Early Ordovician rocks. No major angular unconformities have been recognised in the overlying marine to non-marine sequence, which ranges from Early Silurian to Early Carboniferous. Several hiatuses and a slight angular unconformity, all within the Devonian, may be related to the major events in the Camel Creek Subprovince. A major deformation in the Graveyard Creek Subprovince in the Early Carboniferous had only slight effects in the Camel Creek Subprovince. Movement on the Clarke River Fault was probably an important influence on sedimentation and deformation in the Broken River Province.

Jan 1, 1990

Here, in what is partly a review and partly a personal viewpoint, I take stock of changes in emphasis and comprehension on the subject of basaltic volcanism in the decade that has passed since the completion of the landmark Basaltic Volcanism Study Project (1981). I concentrate attention on the relatively neglected physical-volcanology aspects (in 1988 it was still possible to publish a 340-page book on flood basalts with barely any mention of physical mechanisms).I adopt the useful unifying concept of "volcanic system" to embrace the invariably-present intrusions as well as the volcano; I consider controls exercised by magma-supply rate and modulator-mechanisms on the nature of the system;I emphasize that sheeted-intrusion complexes, consisting either of dikes or inclined sheets (depending on the ability of the system to expand laterally) occur in all eroded major systems and fuel geothermal systems; I show how constraints set by cooling of narrow intrusions cause such complexes to be wedge-like and produce considerable rotations; I consider the role of the level of neutral buoyancy in making magma chambers possible, causing lateral subsurface magma flow and localizing intrusions, while the LNB itself can be accentuated by intrusions; and I examine the possibility that underwater systems could have very different internal structures from systems on land.

Jan 1, 1990

The design and selection of components for belt conveyors is a well known procedure and many handbooks, catalogues and design manuals offer a wide range of detailed information which can be applied to most of the known conveyor problems. The aim of this paper, however, is to investigate the various methods of conveyor drive configurations, and incorporate the latest technical achievements in the control systems, particularly for high capacity conveyor systems carrying ore from pit to processing plants where the lowest maintenance, operating and initial costs are of major importance. Past experience has proven that multi pulley drives can reduce initial capital cost of a conveyor; this leads to the need for better torque control during startup, running, stopping and load sharing. Many methods of torque control are available and have been used in the past. All types have their advantages and disadvantages and must be considered when designing a conveyor or conveyor system. However the recently developed solid state electronic soft start controls utilising AC squirrel cage induction motors are gaining acceptance, especially for a conveyor system where the same control and logic system can be used to transmit startup commands to more than one

Jan 1, 1978

The word "optimization", refers to the search of an economic optimum, or, more precisely, to the choice of technical parameters which will define the more profitable mining project, knowing the values of the economic parameters. In fact, there is no direct way to perform this optimization, because the extremely large number of technical factors involved, from the type of working and its selectivity to the characteristics of the mill and its flexibility, makes it impossible to make a comprehensive survey of all possible projects. Beside, it would be meaningless to engage in such a task as the deposits themselves are not really known, but only estimated, with sometimes a high level of imprecision. Not to mention the numerical instability which would affect such a computation! In addition, the "best" project is not necessarily the one which strictly maximizes a given profit formula. There also exist human factors which have to be complied with, when choosing the cutoff grades for instance. Finally, there are other non-numerical factors which interfere with the choice between several projects: the shape of the bottom of a pit of the layout of the access road for instance.

Jan 1, 1986

By A G. Thompson, E Villaescusa, D Howard

The Western Australian School of Mines (WASM) has developed a facility for the static testing of full-scale ground support elements (Morton et al, 2007). The test facility consists of several stiff steel frames used to support the sample and a screw feed jack is used to load the sample. A large-scale punch test method has been developed to load various shotcrete configurations. The shotcrete is sprayed on to a rock substrate containing a centrally located circular disc. The rock and shotcrete sample is placed on to the sample frame and restrained on all sides. The circular disc is displaced at a constant rate by the screw feed jack which in turn loads the sample. Instrumentation measures the displacement and the load being applied to the sample through the loading disc. The testing method is described in detail and the results from the testing program are presented. The results show that it is possible through laboratory testing to simulate some of the mechanisms of shotcrete support reactions better than conventional beam and panel tests.

Jan 1, 2008

By Fourney W. L, Weaver T. A

A large number of single borehole crater-forming shots were analyzed in terms of correlating the crater parameters with explosive weight. The objective was to determine a scaling rule for which the explosive weights varies over many orders of magnitude and covers many different geologic materials. Included in the data base are type and weight of the explosive, geologic medium and degree of saturation, charge depth-of-burial, crater dimensions, and crater rim (lip) measurements. An alternative scheme to the usual plot of scaled depth-of-burial versus scaled volume removed was desired. The proposed technique uses a plot of the logarithm of the explosive weight, Y, versus the logarithm of the slant length, R', calculated from the known depth-of-burial of the explosive and the measured crater radius. A plot of Log Y in kilotons versus Log R' in meters from all the crater tests in this data base resulted in a straight line with a of slope 0.31 and showed good correlation between the variables Log Y and Log R'. Since the crater data includes many geologic materials, different explosives (including nuclear tests), and large differences in charge weight, the straight line fit suggests that the type and strength of the geologic materials play a subordinate role to explosive energy in crater formation.\

Jan 1, 1990

By Koppe JC, Strieder AJ

The Rivera Crystalline Island (RCI) is an erosional window of the intracontinental Parana Basin that outcrops in the Rivera Department, north of Uruguay. RCI is made up mainly by Precambrian granites, metasediments and granite-gneisses. This island is crosscut by a dextral transcurrent shear zone system, the Rivera Shear System (RSS). The bulk strain ellipsoid was defined by previous work and has allowed the evaluation of shear dynamics. The geometry of the shear system is made up of two shear directions: E-W (P-shear), which turn right to NW-SE direction (R-shear), leading to the development of extensional bends. The shear zone system was developed in brittle-ductile to brittle regimes, under temperature conditions compatible with greenschist facies metamorphism. The shear zones are marked by an intensive fracture cleavage development. Mylonites develop only in narrow, discontinuous higher strain zones. Internally, the shear zones are dominated by intrusive rocks, mainly granites, dacites and diorites. Hydrothermal alteration has been developed in several areas.The economic significance of RCI is given by several small gold deposits, which have been exploited since 1869. One major new gold mine is under development, the San Gregorio Gold Mine. This gold deposit is locally controlled by a dilatant site where R-shear turns right to P-shear. Mine lithologies were deeply altered by hydrothermal fluids in the dilatant structure. This work presents the lineament-structural analysis carried out to identify similar structural patterns in all RCI sites favourable to host other gold deposits. The exploration program also considered remote sensing, geology, geophysical and geochemical survey.

Jan 1, 1997

Recent geological mapping has indicated changes to the stratigraphy of the Pine Creek Geosyncline. The new stratigraphy and interpreted depositional environments are examined in relation to the distribution and genesis of stratabound mineral deposits. Basinward correlations are made with near-shore carbonate and psammite-rudite units in the Rum Jungle region. Most other units in the same region are condensed, indicating long- lived supratidal, intertidal or shallow conditions during most of the depositional cycle. Units containing most of the mineralisation represent the earliest near-shore developments of strongly reducing partly pelitic and evaporitic conditions and contain mainly uranium and base metals. Restricted distal, strongly reducing facies with associated felsic volcanics are also well mineralised, and mainly contain gold, silver and base metals, although some deposits are probably genetically related to synorogenic or postorogenic granites. Mineralisation in other facies is almost all epigenetic hydrothermal in origin, although minor mineralisation is related to volcanics, or dolomitic parts of the sequence. Areas of potential mineralisation include near-shore environments in the north, and carbonate reefs along growth faults. Two suites of postorogenic felsic volcanics and related sediments deposited in shallow water within and around northwest and east-northeast rift systems, overlie the metasediments of the Pine Creek Geosyncline in the south. The suites have potential for volcanogenic deposits, mostly of uranium, gold and copper.

Jan 1, 1984

By J Andrina, D Richards

The Grasberg is a large copper and gold open pit mine operated by PT Freeport Indonesia and located in the high equatorial mountains of Papua Province, Indonesia. The climate is alpine/sub-alpine with little seasonal variation in temperature and rainfall. The annual precipitation varies from about 3000 to 5000 mm over short distances around the Grasberg, but in general, an average daily precipitation of 10 mm per day applies and leaching of the overburden is continuous throughout the year. Mining commenced in 1988, and almost all of the overburden mined up to 2003 was potentially acid forming. The current acid drainage from this overburden is being collected and treated. From 2004 to the end of the Grasberg pit operation in 2014, approximately 70 per cent of the overburden will be potentially acid forming and 30 per cent limestone. A program of laboratory leach columns, field test pads and an instrumented full-scale dump was developed with the objective of defining scale up factors to quantify the acid and metal leaching rates and to evaluate the stockpile geochemistry and control options. The results of an ongoing seven year program have demonstrated feasible scale up between laboratory columns, field test pads and the trial dump in relation to material geochemistry and ARD evolution trends at Grasberg. The potentially acid forming waste types are highly reactive and maximum acid generation rate occurs within two to three years and that maximum copper release occurs within one to two years of exposure. The results also show that the net acid generation (NAG) test provides a good estimate for the potential acid load from overburden types. The chemistry, temperature and oxygen data from the trial dump suggest that oxidation and acid generation is occurring throughout the dump but at a decreasing mass rate with increasing distance from the toe of the dump. It is apparent that convection and/or advection are important mechanisms for the transport of oxygen into and within the dump. Key results and findings of the investigations carried out are presented and the implications of the findings for long-term ARD management at the Grasberg mine are outlined.

Jan 1, 2003

By Regan R

Appin Colliery mines the Bulli Seam with a gas composition of 98.5% methane and 1.5% carbon dioxide. Relaxation of the strata generally occurs to below the base of the Wongawilli Seam, some 40 m below the Bulli Seam, and approxim- ately 125 m above the Bulli Seam, for longwall face widths of 135 m or more. Previous exper- ience showed that when longwall faces were mined for a distance approximately equal to the face width, the mine ventilation could not provide sufficient dilution due to methane emissions from the underlying measures. Postdraining downholes were drilled to intersect the Wongawilli Seam below the operat- ng longwall. These holes were connected to an underground to surface gas range and various suction levels were applied to improve gas drainage. The resulting gas flow rates and purity from all the downholes were regularly monitored and peak flows in some holes exceeded 160 1/sec. The surface plant drained almost 20 million m3 of gas for the period July 1981 to January 1982 at an average methane purity of approximately 70%. Distinct patterns emerged for different downholes from curves illustrat- ing their variations in flow rate with distance subsequent to passage of the longwall face. The difference between free flow characteristics and those obtained with the application of

Jan 1, 1982