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Copper mineralization associated with minor molybdenum, silver, and gold occurs in a hydrothermally altered brecda within a granodiorite mass of Upper Permian age. A dyke system of rhyolite, dacite, and andesite forms plug-like bulges near the breccia and probably caused mineralization as a late stage effect.Base metal sulphides occur as disseminations, fracture and cavity fillings in the breccia. A pyritic halo in hydrothermally altered granodiorite surrounds the breccia and grades into unaltered granodiorite. Drilling during 1969 indicated the grade is subeconomic.

Jan 1, 1972

Within ten months of the first significant intersection on the Vera deposit, approval was given to proceed with a $28.3 M underground development of the Vera-Nancy gold mine. Contrary to what the timeframe suggests, the development of the underground mine was planned in a logical and methodical manner which enabled confirmation of the resource, evaluation of the orebody for mining and sufficient production to recommence milling operations at the Pajingo treatment plant. This paper describes the underlying factors on which the project was planned and developed. The approach has successfully enabled the mine to be in production 18 months after discovery without compromising any future production or potential expansion

Jan 1, 1998

Gold mineralisation at Wapolu lies within an exposed arcuate zone at the decollement contact between a basement dome of high grade metamorphics and an overlying ophiolite sequence. This contact was originally a thrust fault which has since become a decollement zone for gravity sliding in association with basement doming. Hydrothermal models for the gold mineralisation postulate an epithermal system in which fluids were channelled up the decollement with boiling of those fluids causing hydrothermal brecciation and subsequent gold deposition. The alteration assemblages, fluid inclusion data and geochemistry indicate that the upper levels of the system are exposed.

Jan 1, 1987

Underground mine ventilation is now com monly simulated on a digital computer. Such a programme, incorporating natural ventilation has been modified by others to account for methane emission and elevated local tempera- tures. At Wollongong University, the pro- gramme was further developed and extensive interactive graphics incorporated such that any view of the three dimensional mine could be viewed, and superimposed upon that view are areas where a nominated parameter has exceeded a particular value - generally at a nominated time after a particular event and usually a fire/explosion of one type or another. A further programme was developed such that up to 20 'times' could be examined at a particu- lar location after say, a fuel rich fire at some other place in the mine. The output from this programme includes a plot of methane 1, smoke 1, temperature, pressure and air flow versus time - a most useful graphic to observe the limits of safe attendance in a particular Airway.

Jan 1, 1983

By J G. Webster-Brown, K L. Brown

The Waihi Region is host to many low sulphidation epithermal Au-Ag deposits. The Golden Cross mine located at the head of the Waitekauri River, eight kilometres NW of Waihi, was a gold mining operation that placed significant emphasis on environmental management. An assessment of the influence of this mining project on stream sediment geochemistry (Fe, Mn, As, Cu, Pb, Zn, Cr, Cd, Ni, Ag and Se) in the Waitekauri Catchment has been made. Effective waste management during the mine operation appears to have prevented contamination of stream sediment. Trace metal concentrations in the Waitekauri Catchment sediment have generally decreased since 1987, and are currently mainly below the ANZECC (2000) sediment quality guidelines. However, elevated As levels were recorded in the Upper Waitekauri River and Battery Stream, exceeding guideline values. Elevated levels of Cu, Pb, Zn and Cd were found in the Huanui Stream, a tributary of the lower Waitekauri River. This reflects the influence of past mining operations in the valley, as well as natural weathering of hydrothermally altered Coromandel Group andesite. At a number of sites, Mn concentrations also exceeded sediment quality guidelines, and this may be derived from the remediated Golden Cross mine site.

Jan 1, 2003

Change is inevitable but learning from change is an option. Willingness to learn is one of the first lessons that a leader must learn. Get comfortable and get left behind. I propose to outline the main social changes which are taking place and their impact on the Minerals Industry. Also the changing way we do business and what are the skills needed to manage that change and diversity. How are Associations and Institutes responding to this ever changing environment? More specifically, what is my Vision for the Institute to assist professionals to achieve greater and continuing professional excellence in their chosen professions?

Jan 1, 2000

By A Rozendaal

Namakwa Sands, a heavy minerals beneficiation business situated along the west coast of South Africa, is a major producer of titanium slag, pig iron, ceramics quality zircon and rutile concentrate to the international export market. The bulk of the economic mineralisation, which includes zircon, rutile, ilmenite and leucoxene is hosted by a late Cainozoic aeolian succession overlying remnant palaeo-strandline sediments. Relatively younger duricrust layers that cement a significant part of the generally unconsolidated ore compounds the challenging processing character of the primary mineralogy. The complex nature and hardness of the duricrust ore influence their mineability negatively, and can potentially destabilise downstream ore preparation processes. Effectively, up to ten per cent of the entire mineral resource is sterilised as the present infrastructure is not geared to treat the hard-mineralised ore. The metallurgical performance of the primary processing stage, which entails wet density separation, is strongly a function of the quality of the heavy mineral assemblage, liberation state of the economic minerals and slimes content. Elevated concentrations of garnet, a gangue contaminant exhibiting similar physical characteristics as the economic minerals, subtract substantially from the recovery performance of the secondary concentration process, which comprises mainly wet magnetic separation. By contrast, the intrinsic mineral purity of the economic fraction governs its successful recovery to saleable products as stringent product quality specifications apply. Improved mine planning through geometallurgical enhancement of the existing mineral resource model is envisaged to benefit the entire Namakwa SandsÆ mineral beneficiation chain, ultimately aiming to optimise mineral resource utilisation.

Jan 1, 2008

Morning Star Gold aims to enter the ranks of Australia's gold producers, revitalising the Eastern Victorian Goldfi elds in the second half of 2010 - the fi rst gold production in around 50 years from the Morning Star Gold mine, which was once Australia's largest under WMC. This presentation will outline the redevelopment of the Morning Star Gold Mine from exploration to production. Morning Star Gold NL's (MCO) key project area is centred at the historic mining town of Woods Point and nearby Matlock (to the southeast) and Gaffney's Creek (to the northwest), all of which are located in the lower part of the Victorian Alps roughly 60 kms south of Mansfield. Morning Star has literally numerous historic mines and gold bearing 'dykes' on its tenements, many with a rich production history of high-grade gold from quartz reefs and alluvial sources. The area encompassing the Woods Point goldfi eld and the multiple high-grade gold bearing dyke structures located north towards Jamieson and south towards Walhalla formed one of the most significant mining fields in Australian history. Historical gold production was at least 155 t or around six million ounces of over a century of mining with an average production grade exceeding 27 g per tonne. The bulk of this recorded production came from just a handful of mines and of those only three were mined to any great depth. One of the key historical production hubs in this area was the famous 'Morning Star' mine, which is situated adjacent to Woods Point township. The Morning Star mine produced almost one million ounces at 27 grams per tonne, operating fairly continuously between 1861 and 1959 with a break after Jan 1939 due to the devastating 'Black Friday' bush fi res across eastern Victoria. During the early 1940s, the Morning Star was Australia's biggest gold mine. The Morning Star mine along with Walhalla ensured that this goldfield was third behind Bendigo and Ballarat as Victoria's biggest hardrock gold production centre. Morning Star Gold has rebuilt its 100 per cent owned 'Morning Star' mine with a view to producing gold in the second half of 2010. Morning Star is exploring its regional dykes in order to estimate an overall gold endowment and rank local production sources to feed its proposed mill at the Morning Star mine site. Key initial targets (all within 11 kms of the Morning Star mine) are the Waverly, All Nations, Rose of Denmark, Hunts, Wallaby and Loch Fyne dykes, all of which historically produced high grade gold, much of it gained from only shallow workings above the water table in the weathered zone of rocks. Historically the Morning Star mine was developed over 24 levels to a depth of 940 m via one large vertical shaft and a smaller, deeper inclined shaft at the 1900 feet level underground. At present MCO has dewatered and completely refurbished all infrastructure to the ten level (~310 m below surface). MCO knows there are a number of substantially under-explored and undeveloped or partially developed but not stoped areas within the Morning Star mine. As a result, MCO has been carrying out extensive channel sampling and an underground diamond drilling program targeting areas of the mine that were largely unexplored and undeveloped by the last operators of the mine - Western Mining Corp Ltd (Gold Mines of Australia). Four thousand, fi ve hundred pages of archival WMC records have helped the cause significantly. The shaft refurbishment and reconstruction stage is complete. This has been a program that originally commenced back in 1993 and has cost around $22 M. This refurbishment paved the way for the extensive underground resource focused diamond drilling program, which MCO completed in 2008 with two company-owned and operated drill rigs from drill cuddies on level 9 (900 feet underground) of the mine. This drilling, which encountered some stunning grades intersections and multiple visible gold hits, has outlined further production opportunities including 0.4 m @ 1392 g/t Au (MS 410). Metallurgical testing conducted by Gekko Systems of samples obtained from the exploration program found gravity concentration and a leach circuit gave recoveries of ~95 per cent to 99 per cent, or ~92 per cent from gravity alone at a coarse crush (300 ¦m). Currently, the plan is to use gravity to fi rstly produce dore bars on-site from the free milling gold and secondly a saleable concentrate for CIL processing off-site. A purpose built 10 t/h (~80 000 t/a) gravity treatment plant was subsequently ordered from Gekko and is expected to be installed onsite and commissioned in the Q3 2010. The plant features fi ne crushing with a vertical shaft impactor, followed by gold concentration by inline pressure jig, inline spinner and Wilfley table. This is an ABSTRACT ONLY. No paper was prepared for this presentation.

Aug 1, 2010

By Isobe K, Muchi I, Hsieh YS

Theoretical and experimental studies have been made-to clarify the physical and chemical behavior of the tuyere combustion zone of blast furnace. Gas streamlines around this zone were visualized by the use of the two-dimensional equip- ment. Close agreement between the observed stream- lines and the calculated ones is found. The three- dimensional experimental studies have revealed that there exists a so-called dry zone in the neighbor- hood of the raceway and the trickling liquid be- haves approximately like a continuum. A kinetic model is develdped to describe the behavior of coke combustion in the tuyere zone. The model is based on the reaction kinetics, the differential balances of heat and mass, and the mechanics of gas flows. Regarding-the-axial distribution of gas composition in the tuyere zone, good agreement is obtained be- tween the model prediction and the data observed in a working furnace by the other investigators. Cal- culated results-show that the maximum consumption of coke occurs at the intermediate region of the raceway. For the blowing of oxygen-enriched or high -humidity blast, the position at which the maximum consumption of coke occurs is shifted toward the tuyere nose. Similar effect is found when the par- ticle diameter of coke in the tuyere zone is de- creased. The solid flow pattern around the tuyere combustion zone was visualized by the use of the two-dimensional equipment in which the sublimation of dry ice particles in front of the tuyere was

Jan 1, 1981

By Cocker J, Urosevic M

Seismic methods have become common for the detection of low-throw faults ahead of underground coal mining. Surface seismic methods cannot theoretically be used where dykes occur, because seismic waves transmit from the surface down to the seams, and reflect back to the surface. Consequently, where sub-vertical structure such as dykes occurs, the surface seismic method fails.The ability of seismic methods to image dykes depends on the geometry used, the dyke thickness and the seismic wave propagation mode in relation to dyke composition and internal structure. Surface seismic methods find it difficult to distinguish between faults/fractures and very thin dykes (1-2m in thickness) when the dyke's thickness is less than the seismic wavelength. Consequently, borehole seismic methods have to be used to detect the presence of such thin dykes.

Jan 1, 1998

The great problem at Port Pirie and many other lead smelters has always been to keep the lead content of the slags down to a low level. This has been done in the past largely by empirical methods, the lead content varying from less than 1 per cent to over 4 per cent, the more usual figure being something under 2 per cent. Subsidiary to this, but of major importance in the future, was the extraction of the considerable quantities of zinc in the slag. At this stage little was known about the constitution of the slags apartfrom their chemical composition. Some early work on slag constitution was carried out in the B.H.A.S. Research Laboratories between 1919 and 1921, but except for a microscopic examination of a few thin sections the greater part of this investigation wasdevoted to the recovery of the zinc content of the slag by leaching methods.In 1949, therefore, it was decided to initiate a programme of fundamental research into the constitution and properties of the lead blast furnace slags. The information thus gained would give a clearer picture of reactions taking place in the slag, both in the blast furnace and during dezincing.There was also the hope that these results would lead to improved industrial techniques resulting in smaller lead losses, and, taking the long-term view, to efficient methods of producing zinc from the slags.A series of investigations was therefore begun at various centres over a period of time. These were:1. A mineralogical examination of the slags by Dr. A. B. Edwards of the Mineragraphic Section, C.S.I.R.O.2. A study of the thermodynamics of various slag com...

Jan 1, 1956

By D Craw

Previous studies of alluvial gold in Otago and Southland placer deposits have suggested a gold-mercury association for some deposits derived from Caples Terrane schist, whereas alluvial deposits on Torlesse Terrane basement typically have no mercury. A regional study of gold from Otago Schist vein deposits from both Caples and Torlesse Terranes has revealed the presence of both Au-Ag and Au-Ag-Hg alloys in both terranes. Au-Ag alloy (3 - 4 wt per cent Ag) is typical for gold found in most Torlesse vein deposits, and Au-Ag-Hg alloy (3 - 8 wt per cent Ag, 2 - 8 wt per cent Hg) is found in many Caples vein deposits. Au-Ag-Hg alloys are not exclusive to the Caples Terrane, however, as Au-Ag-Hg alloys with up to 4 wt per cent Hg are found in vein material from the Torlesse-hosted, HydeMacraes Shear Zone. In addition, not all Caples-hosted deposits have a gold-mercury association; gold grains from the Carrick and Invincible gold fields have no detectable mercury. The present study characterises gold compositions from various hard-rock vein deposits and has potential for determining placer-source relationships.

Jan 1, 2003

One would anticipate that after 40 years in the mineral industry it would be simple to project the trends at least 5 or 10 years into the future. However the last 20 years, 1950-1970, have been so different in the mineral industry from the years 1930-1950 that I suggest only 20 years or so are relevant to any forward projection.Those, of us that have been about during the last 40 years find it hard to relate the two periods.The first with the depression, low base metal prices, attempts to revive the gold industry, very little export of minerals, and finally World War II and the recovery period.The second, a period of unimagined discoveries and the reappraisal of a wide variety of minerals and metals-iron, coal, bauxite, beach sands, manganese, oil and gas, and nickel, to name but a few.The second period started early in the 1950s and was triggered off by the search for oil in Australia.Rough Range No. 1 was an important milestone in our history because it initiated a series of speculations and the re-examination of much of our thinking about our mineral resources. It lead to the discovery of bauxite and the start of a flourishing aluminium industry.The realization of the extent of the iron ore resources was another, major step and the influx of overseas capital and competence started the large wave of development made effective by the Japanese markets.The momentum of the late 1950s has carried us to where we are today and will undoubtedly carry us further forward in the next few years.All this development in the mineral industry has come at a time when our pastoral industries have reached a difficult period. I have no doubt that if it were not for the mineral industry Australia would at the moment be experiencing one of its blackest eco...

Jan 1, 1971

By Bishop D. J

The Imperial Smelting Process for the simultaneous production of zinc and lead is probably regarded by the ecologist as a necessary evil with the benefits of its products marginally outweighing the adverse effects of its operation. The purpose of the paper is to examine the environmental impact of the process and to provide information which will demonstrate that the process has considerable indirect environmental benefits and that success is being achieved in reducing direct pollution of the environment by the process. About 12 per cent of the world's zinc and seven per cent of its lead is produced by the process. This proportion will increase with the construction of a new smelter in China. After a brief description of the process the paper considers one of its principal advantages, its ability to treat bulk concentrates. The production of these at the mine can have a number of environmental benefits. Less comminution may be required to separate the metals from the gangue than is needed to separate them from each other; recoveries can be improved in flotation resulting in cleaner tailings dams, less power demand and reduced consumption of potentially hazardous reagents. Simplification of mining and above ground ore handling may also give significant benefits . The process is a considerable consumer of secondary materials such as galvanisers' ashes, copper smelter dusts and materials containing zinc and lead derived from steel plant dusts. The majority of these materials are fed to the blast furnace after hot briquetting. The consumption of secondary materials is a considerable environmental benefit since otherwise they would require to be dumped in secure land-fill sites. The operation of the process itself continues to be subjected to increasingly stringent environmental standards of which examples are provided. Details are provided of lead emissions at Avonmouth showing considerable success in reducing these while increasing production. The slag from the process continues to find many useful applications.

Jan 1, 1993

Delivery of effective plant shutdowns is primary to the business success of mining and processing plant operations. This paper sets out a methodology that starts with understanding the business objectives of the shutdown and promotes rigorous detailed planning, effective communication, appropriate governance and effective participation of plant operations personnel. The result is delivery of business effective outcomes.

Jan 1, 2004

The Airport Link Railway utilises innovative solutions to a number of issues associated with underground development and transport infrastructure planning. It is typical of the major change underway in the countryÆs rail and air transport industry. It involves the private sector providing transport facilities in competition with the public sector, a convergence of planning and transport imperatives, the use of the most technologically advanced engineering practices to minimise construction impacts on the community and a commercialised way of developing and maintaining railway infrastructure and services.

Jan 1, 1999

THIS paper deals with the handling of the various materials used in the 100-ton zinc plant at Risdon, and, in view of the magnitude of the works, the configuration of the ground covered by these works, the variety of the rnaterials used, and the large quantities, a very attractive and interesting subject is opened.The works are situated on the right bank of the River Derwent, about four miles above Hobart, the capital city of Tasmania. The Risdon works cover a space of 149 acres, the area being :3800 yards long by 2800 yards wide, and the elevations vary from 6 ft. above high-water mark at the wharf and foreshore to 163 ft. above high-water mark at the power station, these being the limiting points as regards elevation which are considered in this paper. Throughout the paper elevations are given in feet above high-water mark. Fig. 1 shows a general view of the works taken from the opposite bank of the River Derwent. The wharf is clearly shown, with SS Kekerangu loading residue; behind the wharf is seen the inclined conveyor leading to the cakine bin; further up the hill is the leaching division. No. 1 haulage runs to the left of this up to a point on the left of the power station, the large reinforced concrete building at the top of the hill. Below this is the cell room, the largest building on the plant. The roasting division, not very clearly seen, lies at the foot of the main stack, and the casting division lies to the left of this, between the leaching division and the cell room. A large wharf has been construl'ted alongside the works. This wharf is 880 ft. long and 60 ft. wide. It is capable of berthing large overseas steamers, as at low tide there is a depth of :30 ft. of water. The rise and fall of the tide at the wharf is 4 ft. 6in., and the river is navigable at all states of the tide. Just above the company's wharf...

Jan 1, 1923

Comminution Kinetics equations are developed to take into account difference of grindability of mineral components. The equations describing both batch and closed circuit grinding or crushing processes are given. These equations are applied to industrial data to derive comminution kinetic and classification characteristics of the component minerals in a multi-mineral ore. Control strategy based on these concepts is presented.

Jan 1, 1985

By B Mil, D P. Adhikary, M S. Craig, P Rutzou

As shallow coal reserves with easier mining conditions are exhausted, future deep coal mining with difficult mining conditions may face significant economic, technical and environmental challenges. Moreover, due to increased coal production capacity with the new generation longwall systems, predicting adverse mining conditions has become more important than ever before. The potential impact of these difficult conditions is an increase in mining risks and costs. Reliable prediction of rock mass deformation, mine stability and mine water inflow is not only essential for improving mine safety and reduction of coal production costs, but it is also important for the assessment and management of the environmental impact of mining. This paper briefly describes an integrated approach to mine groundwater simulation and prediction. Central to this integrated approach is a three-dimensional computer code called COSFLOW, developed by CSIRO of Australia in collaboration with NEDO and JCOAL of Japan to address the pressing issues of mine water management. COSFLOW incorporates unique features that make it ideal for the simulation of coal mining and examining the interaction between rock fracture, aquifer interference and water flow. This paper also presents an example of an application of the integrated approach and COSFLOW in water inflow prediction at Springvale Mine in New South Wales.

Jan 1, 2006

Particle Mechanics and the Design of Cyclone Tribochargers Triboelectric separation is a dry electrostatic technique that has shown promise in several particle processing applications. A tribocharger uses contact or friction to differentially charge particles of different materials, which are then separated by an electric field. The initial tribocharging process is poorly understood, with tribocharger design and operation largely a matter of trial and error. A better physical understanding of tribocharger operation would therefore be of immense value in the optimisation of triboelectric separation processes. A combination of charge measurements, trajectory modelling and high-speed video has been used to relate charging to particle mechanics in a cylindrical pneumatic cyclone, one of the most effective tribochargers for mineral separation applications, and the preliminary results are presented here. The consequences of these observations for cyclone tribocharger design and operation, and for tribocharger design in general, are discussed.  

Sep 13, 2010