Search Documents

By Johnson I. R, Muir M. D

The Dugald River zinc-lead deposit is located 60 km northwest of Cloncurry. It was discovered prior to 1881, and since 1937, has been the subject of several drilling programmcs which have outlined a resource potential of 60 million tonnes grading 10 per cent zinc, 1 per cent lead, and 30 g/t silver.The deposit is a classical example of stratiform zinc lead mineralization in a black shale host. It occurs within a restricted clastic sedimentary basin within the Corella Formation of Carpentarian (Middle Proterozoic) age. Sabkha, lacustrine and fluvial sedimentary environments have been recognized within this basin. Each environment is characterized by suites of evaporite mineral pseudomorphs, after both shortite and gypsum, indicating that both alkaline and hypersaline environments prevailed at different times during basin evolution. The Dugald Slates which host the zinc-·lead mineralization are lacustrine in origin. Thin Mount Isa-type K-rich tuffite beds occur in the Dugald Slates and in the sabkha sequences.The basin as a whole appears not 10 have been marine, and 10 have had strong tectonic controls on its depositional history.The mineral deposit itself is conformable within the Dugald Slates and many primary sedimentary and soft-sediment deformation structures are preserved. It has a strike length of 2 km, average width of 10 m, and a westerly dip of 50-80 . Drilling suggests continuity to 1000 m vertical depth. The predominant sulphides are pyrrhotite, pyrite, sphalerite and galena in graphitic slate and quartz-carbonate ganguc. Anomalous concentrations of barium, manganese, cadmium, mercury and antimony are present in the ore.The deposit crops out over a distance of 2 km as a gossan ranging from 5-15 m in width. There is a striking vegetation anomaly over the gossanous outcrops. The gossan is enriched in lead, silver, antimony, barium, titaniulll, silica and iron, with respect to the primary mineralization. The depth of total oxidation reaches about 20 m.Cieochemical and geophysical test surveys over the deposit give pronounced anomalies.

Jan 1, 1982

The mining industry to the lay mind is one which appears peculiarly dangerous, partly because the accidents which take place are usually of a very tragic nature, and partly because other, industries claim victims more from disease than fromviolence, and their fatal nature is not advertised to the same degree so that in spite of this idea of unusual risk, it is a fact that mining will compare favourably, as regards vital statistics, with nearly all other trades requiring special training.Neverthelessthere are a larger number offatal and serious accidents occurring year by year than one would like to see, and could the deaths which take place by accident be eliminated, it is safe to say that mining would become one of the most healthy of all species of skilled labour. If we examine the accidents appearing yearly in the reports of the Mining Departments of the various colonies, it will be at once admitted that many of them need riot, and in many cases ought not to, have occurred.It is, therefore, the object of tbis essay, to pass under review the ordinary precautions which should be adopted to minimise, as far as possible, the dangerous factors whereby fatalities are brought about.

The material presented in this paper describes experimental work to determine the effect of variations in suction nozzle design upon inlet flow conditions. Four entrance profile shapes were examined under controlled conditions of slurry flow and it was found that the straight ended nozzles had consistently higher entrance losses than the straight taper or the ellipse, and that the circular arc profile nozzles were the most efficient. Subordinate considerations were the measurement of the quantities and the forces involved.As the work progressed, three distinct phases in the pattern of flow were apparent and the static pressures in each were carefully examined. An inlet zone was found to be unstable in changing boundary conditions, a transition zone was largely independent of slurry density and in a zone of stability the pressures were found to be directly related to the characteristics of the flowing pulp. In this zone pressure measurements were reproducible within ± 2 per cent regardless of changing boundary conditions.The effect of varying the "1" parameter of nozzles with a part circular entrance profile was examined and it was found that flow conditions approaching the ideal were obtained when the radius of curvature was between 0·40 and 0·550.

Jan 1, 1966

THE North Mount Lyell Mine is situated on the southern side of Mount Lyell at an altitude of 1750 ft. above sea-level. The average rainfall is 117 in., and there are generally several light falls of snow during the year. Despite the heavy rainfall, which is fairly evenly distributed over each of the twelve months, the climate is equable and not unduly rigorous, and, provided that the mine employee is suitably clad, it is only on exceptional days that he experiences any discomfort by becoming wet journeying to and from the mine.The majority of employes reside at Queenstown, and are conveyed by special trains to and from the top of the haulage, which is less than a mile from the mine. The mean surface temperature at the mine is 46° F., with a maximum variation from 26° F. to 85° F., the relative humidity generally being higher than in other districts. The rock temperature is 48° F. on the 200-ft. or Main Adit level, and 54° F, on the 1200-ft. level, giving a rise of 6° F. for 1000 ft. in depth.The ventilation of the mine is natural, the downcast being served by the Crown and Blocks shafts and the Crown mullock pass, and the upcast air is carried away from the workings by the Main shaft and the Nos. 1 and 2 mullock passes. The quantity of air circulating varies from 25,000 cub. ft. to 35,000 cub. ft. per minute, the greater quantity moving in the colder weather. The downcast air in traversing the wet shafts becomes saturated and enters the level at the rock temperature of 54° F. in winter and about 56° F. in summer, while temperature readings of the outcast air indicate that it varies very little.In the southern end of the mine the Blocks shaft downcast air upcasts through the different stopes, and their mullock passes, to the level above for each level to the 700-ft. level, where it passes to one of the main uptakes. The prown shaft downcast air supplies...

Jan 1, 1927

Factual data about the sedimentation in the Newcastle Coal Measures are presented. Data concerning the total coal measure sequence (isopachs, sand/shale ratio, and total coal thickness variation), data about three coal seams (Borehole, Dudley, and Victoria Tunnel) and data about interseam conglomerate units are discussed.From this data conclusions are drawn about the coal measure environment. The western edge of the coal basin, the Lochinvar Dome, although a high feature, was apparently stable during coal measure time. Despite its height it apparently supplied little sediment to the basin.The northern and north-eastern edge, which was unstable, supplied most of the coarse detritus (including the conglomerates) to the basin. The conglomerates show patterns of fluvial origin but after a period of "normal" variations in pattern they become restricted to two parallel zones evidently tectonically controlled. Deposition of conglomerates is episodic and separated by periods of coal formation when deformation was apparently slight. Formation of each of the three seams considered followed a rather similar pattern- each show development of thick coal around the basin edge and poor thin coal in the "axial" region of the present synclinal structure.Evidence of ill situ formation of some areas of the seams is discussed and periodic deformation of the basin during coal measure time is postulated.The unusual character of this coal basin, in particular the very coarse units, is stressed, despite the presence of many "normal "coal basin features.

Jan 1, 1970

The labour question is one that has caused mine managers much thought and anxiety and is likely to continue to do so as long as human beings exist. The difficulty is to devise some arrangement whereby the interests of miner and mine ownerare identical. Mines cannot be worked without capital, and capital is no good without labour, yet, though both have the mine in common, their interests are not exactly the same. Some men are happy so long as they can scrape through by exerting themselves as little as possible, but capitalists do not work mines for charity, they want some return for their money.Where a large number of men are employed there are bound to be examples of all sorts, good and bad, and it is because one cannot depend on all, that different methods of employment have to be adopted. Which method is selected depends to a great extent on the labour market, local conditions, nature of the ore and the way in which it occurs.A big step towards success is obtained by securing the services of good bosses, not only those who know how work should be done, but men who have a knowledge of human nature. It is a big mistake to be too lenient with a man, also to be unnecessarily harsh. A good boss will always be sought out by good men who have worked under him before, or who have heard of him from others. By a good boss we do not mean one who employs two men where one would do, or who lets the men loaf...

Jan 1, 1901

By L H. G McClean

Environmental, social and governance (ESG) factors have always been important to the minerals industry and is now considered one of our most important opportunities (and risks). Getting it right from the beginning is critical for the minerals industry, and that starts with mineral exploration. Exploration, or the process of investigation of an economic mineral deposit, is generally low impact and short-term. Exploration operations vary in size and scale and often shift priority, focus and location relatively quickly. Australia is a highly regulated jurisdiction with different regulatory systems and requirements in every state and territory. Most mineral exploration is undertaken by junior exploration companies or ‘explorers’. Exploration companies are lean operations with limited staffing and resources, traditionally with no income apart from funds raised or work through partnerships. Funds are tight and administrative investment is minimised so that investment into activity on the ground is maximised. All these variables mean that understanding and implementation of ESG frameworks for an exploration company can be challenging. ESG is a fast-moving sector with currently multiple frameworks and reporting standards. Interest from community and government stakeholders as well as investors and off-take partners has been growing, with mandatory reporting soon to be implemented. The upcoming changes to the JORC Code will ensure that ESG considerations will be a key component of all public reporting. Resources have been developed to support explorers implement, manage and report on ESG considerations. Due to their scale, agility and direct importance of land access and social licence, many explorers are not the ‘cowboys’ (or ‘cowpersons’) of the industry, but industry leaders in ESG. Strong interest and leadership have led to innovative practices and strongly embedded vertical frameworks that directly contribute to social licence to operate.

Sep 1, 2024

By Z Chang, S A. Mrozek

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Antamina, Peru is the largest Cu-Zn skarn deposit in the world. Skarn mineralisation is focused around a multiphase Miocene intrusive complex comprising at least eight distinct phases identified by cross-cutting relationships, including truncated veins, xenoliths and chilled margins. Skarn alteration and mineralisation, as observed in drill core, remain open at depths exceeding 2.2 vertical kilometres.Porphyry intrusions occur as four major phases with subphases (from oldest to youngest): P1 (a, b), P2 (a, b), P3 (a, b) and two dykes of uncertain timing named Oscarina-1 and Oscarina-2. P1a is a hornblende-biotite quartz diorite porphyry with pervasive K-alteration, local endoskarn and 30–40 per cent sheeted quartz veins, all of which obscure original igneous textures. P1b dacite porphyry is a minor unit with <10 per cent phenocrysts and <3 per cent quartz veins. P1b cuts P1a; P2 dykes cut both units. P2a porphyritic biotite quartz monzonite contains K-feldspar megacrysts up to 4 cm long, local K-alteration and 2–80 per cent quartz stockwork veins. P2b biotite monzonite porphyry contains approximately 50 per cent phenocrysts and typically <10 per cent quartz veins. P3a (brown groundmass porphyry) and P3b (coarse phenocryst porphyry) are minor in volume and extent, and both cut P2 bodies. Oscarina dykes comprise two separate but parallel bodies. Oscarina-1 is a feldspar-phyric rhyolite porphyry, while Oscarina-2 is an intensely chloritised andesite porphyry. Oscarina-1 has a U-Pb (laser ablation inductively coupled mass spectrometry (LA-ICP-MS)) age of 10.1 ± 0.1 Ma, whereas P2 U-Pb zircon ages (LA-ICP-MS) range from 10.0 ± 0.2 Ma to 9.9 ± 0.3 Ma.All the intrusive phases contain quartz veins, with P1a and P2a having the most intensive K-alteration and most abundant quartz veins ± endoskarns. Each phase may have contributed to mineralisation at the right depths and within favourable wall rocks (ie marble) during uplift of the Antamina structural block. Therefore, a model of multiple intrusions during continuous uplift explains the vertically extensive (>2.2 km) skarn and mineralisation at Antamina.CITATION:Mrozek, S A, Chang, Z and Meinert, L D, 2015. A model for the intrusive sequence and Cu-Zn skarn formation at the Antamina deposit, Peru , in Proceedings PACRIM 2015 Congress, pp 423–430 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By S Jephcott

The McArthur lead-zinc-silver deposit is of the stratiform type. It consists of a mineralised bituminous shale sequence containing some tuffites, numerous graded beds and isolated slump breccia horizons. The principal sulfides; pyrite, sphalerite and galena, are essentially restricted to the shales and the genetically unrelated turbidites contain only minor mineralisation. The geochemistry of the deposit has been investigated with respect to the stratigraphic column and mineralogy of the sediments. A sedimentary origin is advocated for the deposit. Volcanism, thermal spring activity and high salinities, perhaps related to the Emu Fault, are considered as contributing factors to ore genesis. The metallurgy of this deposit is discussed in relation to its geologic history.

Jan 1, 1971

INTRODUCTION ò World coal production, Exporters and Importers òNew Zealand Exports, Markets and Products ò Types of Markets and Price Setting ò Bench Mark Prices and Exchange Rate ò Transport ò International Marketing - Key Factors ò Coal New Zealand , the Challenges

Jan 1, 1996

Tin mineralization in both eastern and western Tasmania shows a spatial correlation with middle Palaeozoic biotite granites and adamellites. The range of composition of these granitic rocks is restricted with respect to Mg, K, and Na content. Because this compositional restriction is shown by granitic rocks from other tin provinces, the concept of a genetic relationship between these granites and the associated tin mineralization is reinforced, and similar concentration mechanisms may be involved.Gold mineralization is largely restricted to eastern Tasmania and in contrast to the tin mineralization is rarely spatially associated with the middle Palaeozoic granitic rocks, although most authors have suggested a genetic correlation with hornblende and/or biotite granodiorites.Although few analyses are available, the granodiorites that are spatially associated with gold deposits exhibit similarities to granitic rocks from gold provinces elsewhere. These features suggest a possible genetic relationship between gold mineralization and the granodiorites.The composition of granitic rocks may be used as an aid to exploration in delineating areas of potential tin and gold mineralization in granite terrains.

Jan 1, 1970

By H North, J Barringer, S McNeill, D Pairman

Models of ground surface elevation, slope, aspect, curvature, roughness, deformation, as well as other features are gathered together in the term Digital Terrain Model (DTM). DTMs can be generated from a wide range of technologies such as ground surveying, aerial and satellite imagery, including both active and passive sensors. Some elevation derived parameters, such as roughness and slope, can be measured directly using innovative active sensor technology and smart processing, rather than via traditional processing of elevation information. Such models are used as part of a visual interpretation process, and increasingly for computer-assisted analysis using visualisation technology. There is an ever-increasing demand for DTM information to be used in the mineral exploration and mining industry, and consistent pressure from industry to develop models of higher spatial resolution, higher accuracy, and better overall reliability, regardless of the world-wide location of interest. This presentation will survey the range of techniques available for DTM generation, including active (LIDAR, SAR interferometry and differential interferometry) and passive (optical or SAR stereo) methods, as well as interpolation methods (contour or structure interpolation), and the economic placement of these various techniques in the local and regional context. The research issue oftrue-ground elevation models and slopes is also addressed, using LIDAR and SAR polarimetry as signpost technologies. Particular emphasis will be given to the strengths and limitations of new data sources that will, over the next few years, make the acquisition of elevation models of remote regions of the world inexpensive and relatively accurate.

Jan 1, 2000

For small particles of niekel flotation eoncentrate (av. size 50 pm) the predominant heat transfer mechanism under suspension smelting conditions, prior to ignition, is conduction from the gas and not radiation from nearby hot bodies. Results of laboratory tests using gas temperatures 380-700°C and furnace wall temperatures 380-1100°C were in accord with heat transfer theory. In practieal flash smelters earlier ignition, and hence better utilization of the space in the shaft, would result from introduetion at the top of the shaft of gases hotter than the ignition temperature of 500-600°C.

Jan 1, 1979

By B W. Riddol1s

The 1983 Energy Plan calls for an increase in North Island coal production from both underground and opencast sources from the 1982/1983 production of 843 000 tpa to approximately 3.4 Mtpa within the ten year period to March 1993. This increased production is scheduled to come from the following sources: Huntly West No 1 underground mine reaching full production of 1.26 Mtpa. Huntly East underground mine increasing production to 750 000 tpa. The proposed new Huntly West No 2 mine producing 100 000 tpa in its first year of operation û 1992. The proposed Ohinewai opencast producing 920 000 tpa for supply to the steelmaking plant at Glenbrook, replacing Weavers opencast which will be worked out in 1990. Rotowaro opencast producing at 220 000 tpa (currently being achieved). Two additional sources of supply which are not scheduled to begin production for at least ten years, and both of which have been designated for coal fired thermal power generation, are the Maramarua and Mokau coalfields. It was originally envisaged that development of both coalfields would be a combination of underground and opencast mines. The form of development is yet to be confirmed by detailed feasibility studies. The location of the Maramarua, Ohinewai (Waikare Coalfield) and Mokau deposits is shown on Figure 1. Worley Consultants Limited, in conjunction with their partners Rheinbraun Consulting GmbH (Germany) and Longworth McKenzie Pty Limited (Australia) have been involved with investigations and mining assessments for the Maramarua, Mokau and Ohinewai prospects. The Maramarua and Mokau studies form part of the New Zealand Coal Resources Survey programme of updating information to the Pre-Feasibility Mining Assessment level before proceeding to detailed feasibility studies. The Ohinewai study was commissioned directly by Mines Division to investigate the feasibility of mining coal by 1989 before reserves at Weavers opencast are depleted. This paper describes typical studies which are now being commissioned by Mines Division to investigate large-scale mining development and the effect geotechnical-conditions may have on coal recovery. The magnitude of these projects is reflected in the proposed outputs û up to2 Mtpa from individual mines û and the introduction of new continuous mining systems for both underground and opencast mines on a scale which has not previously been contemplated.

Jan 1, 1984

The centrifugal elevator invented and patented by the writer is designed for the purpose of conveying the tailings of a gold dredge to such a distance that it shall not impede the dredging opperations. Formerly this was usually accomplished by means of a belt of buckets travelling round a ladder set at an angle of about 30 degrees to the horizontal, but this meant heavy wear and tear on the travelling buckets and the tumblers actuating them. The centrifugal elevator throws the tailings through the air to the required height and distance and it is manifest that during their flight from the elevator to the heap there is absolutely no wear and tear, only the attraction of gravity and the resistance of the air has to be overcome. All then there is left to he considered is how to throw the stuff with the minimun of prower and wear on the elevator.The elevator consists of a cam-shaped steel casting with a disc of mild steel plate on either side: These side plates project a few inches beyond the tips of the beaters, in order to prevent odd stones from straying in an undesired direction; they serve also to prevent extra large stones from reaching the beaters, for they slide off the rims into the water.

Jan 1, 1904

In presenting this address I am conscious of the honour that has been paid me in my election to this important office, and I am very aware that I follow, in the position of President, many distinguished men who have led the Institute over the 70 years since its inauguration in Broken Hill in 1893.It is perhaps appropriate tonight that I intend to talk about a metal which recalls the birth-place of the Institute, and is also one with which I have had a direct association throughout the whole of my working career. This metal is Silver.Silver is associated traditionally in everyone's mind with money and silverware, and has always been prized for its natural beauty and elegance. It is today one of the few metals in which world consumption has outstripped production, and the events which have occurred to bring about this situation make an interesting story.In telling this story, I propose firstly to indicate our development as a silver producing country, give an historical review of the metal, trace its use as currency and the factors influencing its price, and then say something of the old and new uses of silver. Finally I shall give some comments on silver production in Australia today.Australia, with 6-5 per cent of the world's output of silver, ranks sixth among the producer countries and over the years has contributed 892.5 million ounces to the world's supply which, based upon production since the discovery ofAmerica, is estimated to have been 22,150 million ounces or nearly 680,000 tons.Although our production appears relatively small by...

Jan 1, 1963

Mr. BRADFORD said :-On assuming this chair, which has been occupied by so many gentlemen of conspicuous ability; my first words must be an expression of the gratitude I feel for the honour you have done me in electing me to be your President for this year.When considering the subject matter of this address to you to-night, quite frankly may it be stated that for a long time I was on the horns of a very great dilemma, for while I could discourse on the modern political trend in relation to our industries at great length, it appeared to me that this was not the place for such a discussion. Next I turned to a consideration of whether a discourse on the theory and practice of iron and steel would be of interest.I, however, banished this idea also from my mind, because it appeared to me that you have already had a surfeit of this on your visits of inspection to our local industries and I did not want in any way to be held responsible for the iron entering into your souls! I therefore propose, with your kind consideration, to address you on other subjects of common and vital interest to all.My first words and thoughts turn on the absolute necessity of eliminating waste in our methods. If we are to succeed in our...

Jan 1, 1926

In the Bendigo district, with its large number of comparitively small leases worked by separate companies, we might naturally expect to find many different arrangements of winding machinery and, as a matter of fact, there are steam winches, old portable engines, single and duplex geared engines, twin engines on the first motion, and in one instance a single engine on the first motion, all employed for hauling purposes from depths of 1000 feet and over.It would be impossible in the compass of this paper to discuss at all fully the various arrangements of winding gear employed on the field the writer can simply refer to some of the more prominent features, in the hope that the information may prove of interest and benefit to the mining community. In criticising our machinery it must be remembered that when many of the plants in use at the present time were erected, they were not intended to wind from more than one third of the depths now common on the field; but so long as the machine could be made to haul a tank of water from the bottom of the shaft it has remained, the greater power required being obtained by increasing the piston speed and altering the gear wheels to suit. The consequence is, of course, that in some of our mines the speed of winding is painfully slow this feature, however, though certainly not consistent with modern ideas of economical mining, does not so seriously affect Bendigo as it would other fields, for the comparatively small quantity of stone to be raised from a given reef by some...

Jan 1, 1902

Samples of a refractory copper ore were examined to test their response to segregation roasting, flotation, and acetonitrile leaching. Recoveries in the segregation roasting stage were between 60 and 100 per cent, while flotation recoveries varied between 60 and 85 per cent in cleaner concentrates assaying 25-40 per cent copper.The fraction of the copper which could be leached from the concentrate by an acetonitrile/sulphuric acid/cupric ion leach solution varied from 16 to 97 per cent, the lower recoveries being correlated with the presence of sulphide in the concentrate.

Jan 1, 1973

The published liquidus data on the Pb-PbS system have been correlated on the basis of one-coefficient Margules equations. Thermodynamic properties of the components of this system have been obtained, and it has also been found that the calculated miscibility gap of this system exists over a very narrow range of temperature (1041 to 1058°C).

Jan 1, 1972