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Roasting of zinc concentrate at the Risdon Works of the Electrolytic Zinc Company of Australasia Limited, (E.Z.), is carried out in two fluid bed roasters capable of treating 450000 tonne/yr, or sufficient for the output of 220000 tonne of salable zinc. The furnaces were constructed by Lurgi, Australia, to the basic design developed by Vieille Montagne Company of Balen, Belgium. The advantages of fluid bed roasting include a higher metallurgical efficiency in sulphur oxidation from a feed which does not require any pre-grinding, mechanical reliabil- ity through the absence of any moving parts within the furnace and the capability of being scaled up to a large unit.

Jan 1, 1977

By Mike Sharwood

This subject is to be discussed in greater depth by Mike Sharwood. It has also been the subject of a mini-symposium by the Melbourne Branch of the AusIMM in October, 1993. The papers from this symposium were distributed to the membership late last year "to raise their consciousness and to promote greater awareness and understanding of the wide range of liabilities that may arise". An introductory paper by Nicholson outlined the many areas in which liability may arise with particular emphasis on expert reports, eg: Takeovers Schemes of arrangement Acquisitions from associates Prospectuses Related party transactions Directors' duties Continuous disclosure Other influences (environmental, occupational health and safety, trade practices)

Jan 1, 1994

By S Slusarczyk, Z Kozlowski

Vibration of surface caused by seismic quakes can make a risk to great mining costruction. We have to do with this risk in the Belchatow open cut mine where seismic quakes of various energy and range have occured since the end of 1970s. The seismic risk influence on the mine structure with the special attention to the slopes of an internal dump has been presented. Hydrogeological and geotechnical conditions of the lignite mining and internal dumping of overburden and ash from Belchatow power plant have been considered. Seismic activity in Belchatow open cut from 1979 to 2001 was described and the connection between mine working and seismicity of this area was investigated. The energy and approximate location of the quakes and seismological parameters of the strongest ones observed from 1995 to 2001 were presented. The mechanism of the quake focuses was determined by means of the primary-arriving wave method. Stability of the slopes was evaluated by means of the Fellenius method. It has been found that seismic events occured in Belchatow region may cause only local eboulements whereas there are not any safety risks to the stability of slopes of the internal dump in Belchatow open cut.

Jan 1, 2003

By Barns K. E, Munro P. D, Brindley S. K

Ernest Henry Mining Pty Ltd started production in August 1997. The Ernest Henry orebody consists of two distinct parts, a complex supergene ore zone overlying a primary ore zone. The economic copper minerals in the supergene ore are chalcocite

Jan 1, 1998

Most of the copper deposits in the Lachlan Geosyncline fall within areas having either a common host rock, mineral assemblage, form of ore body or time and method of emplace- ment. On this basis a Cobar-type ore has been recognised in the deposits of the Cobar -- Mt. Hope - Melrose region. The copper ores in the Tottenham-Girilambone area to the east have a different mineral assemblage. In the more rugged Central Highlands nearer the coast copper deposits are generally concentrated either in one of several Ordovician andesite belts, particularly between Wellington and Woodstock, or within Silurian acid volcanics developed in irregular fashion over a considerable portion of this region. In only a few instances is copper known in the granite batholiths which adjoin these volcanic belts. Native copper and magnetite are characteristic of the deposits of the andesite province and it is possible that future mineragraphic studies will indicate significant differences in the base metal sulphides of both the andesitic and the more acid volcanic belts. Ores having similar mineralogy and form to the Captain's Flat deposit are known at various localities in the eastern segment of the latter belt. In the Gundagai area several small copper deposits with associated nickel minerals have been developed in the Coolac Serpentinite belt.

Jan 1, 1969

By Gardner CE

Uranium occurrences and the probable Australian reserves are discussed and the recovery and processing methods used in treatment plants at Radium Hill and Port Pirie, S.A., Rum Jungle and Moline, N.T., and Mary Kathleen, Qid. are reviewed. The broad aspects of the application of nuclear power in Australia are then considered, and those factors of greatest significance are highlighted. It is these factors that are most likely to dictate the future role of nuclear generation in Australia. In commenting on private industry applications, the paper emphasises that each case must be considered on its own merits, and a warning is given that general statements can be misleading. In the long-term situation nuclear power is considered to be capable of playing a leading role and the discussion covers desalination and high load industries although short term applications appear difficult to justify. In non-power applications for nuclear energy reference is made to isotopes and the uses of nuclear devices in mining and civil engineering with a pertinent comment on safety.

Jan 1, 1970

The future of the Tasmanian mineral industry can only be estimated from a knowledge of the past, and armed with this knowledge an orderly plan for the future can be developed. Brief mention is made of the major historical developments through to the present day, with past and future development areas clearly mapped. Areas of importance which have been discussed are divided into the mining of metals, fossil fuels and non-metals; and the process- ing and extractive industries. Discussion then follows on the current general non-insular pressures on the mining industry, the energy crisis, scrap, world shortages, new techniques, inflation, and the effects of exploration on the environment. This is then followed by a discussion of the advantages of Tasmania as a mining state and a cataloguing of the present exploration and some possible areas of future development. From this a suggested plan emerges for the future development of the Tasmanian mineral industry, to incorporate the latest technological advances and by planning to meet the challenge of survival and growth in a turbulent environment.

Jan 1, 1977

By G A. Davis, D G. Laughton

The great variability of mineral and energy prices has motivated some governments to incorporate a windfall profits tax into their mineral taxation regimes. Windfall profits taxes are a means for governments to capture additional mineral revenue when mineral prices are considered higher than some historic level. Governments need to be aware of the effects of such contingent taxes on the exploration, development and operating decisions of mining companies. Mining companies need to be able to calculate the full impact of windfall profits taxes on the economics of their projects. This paper examines the valuation of a multi-phase copper-gold project in the presence of a windfall profits tax. Real options Monte Carlo simulation is used to characterise the different exposures of the mine owner and of the government to the risky cash flow streams that they receive from the project. The results highlight that Monte Carlo simulation paired with the real option valuation method is able to account appropriately for the differing risk exposures, while the traditional discounted cash flow valuation model is not. Our key conclusion for governments and mining companies is that the impact of contingent tax and royalty terms can and should be assessed using advanced valuation techniques, and the results used to improve contract designs under the constraint of actual and perceived fiscal system stability.

Jan 1, 2007

THERE is available a considerable amount of literature concerning the practice, and, to a smaller extent, the theory of ventilation as it applies to coal mines. Publications considering the subject of ventilation of metal mines from a practical viewpoint are much less numerous, whilst the treatment of the theoretical aspect of the question (except in so far as is common to coal mining) appears to have been almost neglected. This may be due to one of two causes (a) That in many metal mines (especially those which have not attained a great depth), on account of the greater number of connections with the surface, as compared with coal mines, natural ventilation has sufficed.(b) That in metal mines where the foregoing is not the case the solution of the ventilation problem from theoretical considerations has been regarded as involving so many complications that any attempt at the determination of a set of concrete ventilation figures applying to and throughout the mine would be futile. Whilst it is freely admitted that the difficulties inherent in the application of theory to the ventilation of metal mines are numerous, it must also be admitted that few attempts have been made to overcome them. The ultimate aim, of course, would be the collection of sufficient data to enable the probable behaviour of the air-currents throughout the whole of the workings of any mine to be accurately predicted under any particular set of circumstances. Failing the attainment of this goal of perfection, it would at least appear that much valuable information might be obtained. In ventilation, as in...

Jan 1, 1921

Geological modelling is a crucial preparatory stage to most facets of the mine planning of an orebody. The process of modelling involves skilled geological interpretation. Recent innovations in computer software and graphics hardware provide many tools which can be used to dramatically improve on manual methods of interpreting orebody data. Geological interpretation can be carried out quickly to produce accurate block models for many orebody attributes, such as grades, and these models can be easily updated locally as exploration and mine development data become available. The speed of the modelling process coupled with the mass storage capabilities of the computer now allows geologists to optimise the geological model or carry more than one model through to the mine planning phase.

Jan 1, 1987

The paper examines the possibility of applying the monolithic packing technique developed in the UK to the division of wide development drivages in Australia, so enabling double entries for longwall retreat panels to be created from shortwall units. The monolithic pack of the UK therefore becomes a monolithic partition in this proposed Australian application. A method developed for the analysis of the load development in packs installed behind longwall advancing faces is adapted and used to predict the support performance of the monolithic partition. Conclusions are made regarding partition construction and possible rates of advance.

Jan 1, 1986

Despite mineral sand occurrences having been noted since the 1970s, the Wemen North Mine is the first operation to commence commercial mining within the inland Murray Basin. The deposit was discovered in the 1990s and, following lengthy resource development, mining commenced in 2001. This initial mine was established as a pilot operation to test the commercial viability of mining in the Murray Basin, with subsequent expansions planned if the mine proves successful. The deposit lies beneath arable farmland close to the Murray River and is hosted by Pliocene marine sands, with a geometry resembling a classical beach strand placer. The operation utilises traditional dry mining overburden removal techniques, with ore mining carried out using a floating dredge and concentrator. This paper looks at the geology of the Wemen North deposit, the mining techniques and challenges as well as grade control practices employed to mine this palaeo-beach placer deposit.

Jan 1, 2003

By I Sheppard, A Hills

This paper describes a multi-lift bench stoping method introduced recently to extract the narrow silver-lead-zinc orebodies at the Isa Lead Mine. Cut-and-fill methods were chief mining methods for the narrow orebodies at the mine over 35 years ago. Benching methods were introduced approximately two decades later, and quickly replacing the cut-and-fill methods. The benching methods had improved both the economy scale and safety of the mining operation. The multi-lift benching method combines a number of bench lifts into a single stope to further improve the operational efficiency. Three stopes in the initial multi-lift benching trials are described.

Jan 1, 2003

By G K. Searle

In Australia, coal mines have generally not adopted filling to increase mining recovery. The aim of this project, entitled æImproved recovery in highwall mining using backfillÆ, was to examine the feasibility of using fill to improve recovery in highwall mining. Current fill practice was reviewed for metalliferous as well as coal mining, both here in Australia and overseas, for its applicability to highwall mining. Studies were then made at a conceptual level to determine whether fill could be economically used, to determine appropriate sources for fill and to trial key aspects of fill behaviour. A review of filling methods led to conceptual studies being undertaken on seven filling methods and these studies demonstrated that fill could be used to improve recovery. These studies were then further refined. Selected filling materials have been reviewed and laboratory tests have been made on these to assess their suitability.

Jan 1, 1998

The importance of the minerals industry to Australia is briefly reviewed and the professional specialists essential for the industry identified. The average first degree graduation numbers in geoscience, mining engineering, metallurgy/materials and chemical engineering are shown and compared with the postgraduate numbers. Demographic trends in population are reviewed and the implications for the required numbers of trained specialists indicated. Short/medium and long-term possible solutions to potential shortages of trained personnel are canvassed.

Jan 1, 1997

Australis Mining N.L. operates a continuous mode carbon-in-pulp (CIP) gold plant, processing sand and slime tailings from previous gold mining operations in the Norseman area. Plant design is that of conventional countercurrent contact between pregnant pulp and activated carbon. Gold desorption is achieved by the Zadra process using near boiling tempera- tures and atmospheric pressure. Process water is drawn from nearby Lake Cowan (saline). The plant operates at, or above, design specification of 400 dry tonnes per day. This paper describes the plant design and operating processes utilised in optimising throughput and gold recovery. TNTDnPTTnmTnM Favourable world gold prices and substantial reserves of sand and slime tailings prompted Australis Mining N.L. to construct a gold extraction plant during 1981. The projected plant throughput was set so as to complete treatment of available tailings over a three year period. Metal- lurgical tests indicated that, with a regrind facility satisfactory gold recovery could be achieved using a countercurrent CIP process. Reflecting the entry of Australis Mining N.L. into its first large scale treatment operation, the plant design emphasised simplicity but effectiveness of Operation.

Jan 1, 1982

Diamond drilling was first carried out at Norseman in the Princess Royal Mine, early in this century. Little concentl'ated drilling was done from then until Western Mining Corporation commenced drilling in 1934. Since then Central Norseman Gold Corporation N.L. has continually employed diamond drilling in exploration of the field. After 1946 the advantage was seen of applying broad pattern surface drilling at Norseman in the reef exploration. In 1953, as a result of the steeply rising cost of drilling and the time taken to penetrate surface material by light equipment, heavier drills and new rigs were introduced. The surface drilling programmes called for a greater monthly or annual footage and to satisfy this new techniques were introduced. The Mitchell-21 machines were discarded and A-3000 machines were installed, firstly under a 48 ft. fixed tower, then mounted on a truck with a 20 ft. tower, and finally on a truck carrying a 40 ft. tower. With the mobile units a compressed air compressor is attached. By use of compressed air with either the Reed roller or Hawthorne bit, rate of penetration of overburden is greatly increased. The mobility of the truck mounted machines has greatly reduced the time required to move from one hole to another, and the use of heavier machines on a three shift per day basis has considerably increased the footage per shift. The general result is an increase to 1,500 ft. of drilling per month per machine, while costs have been greatly reduced in spite of increased wages and diamond prices.The underground drilling technique is described. Analysis of performance has not been made because the drillers performance is subject to shaft routine and service.INTRODUCTIONGold was first discovered at Dundas in 1894, and at Norseman, 14 miles north, in 1895. From that tirpe until 1935 mining activity fluctuated. Following the mining revival in 1935, production in the field has remained comparatively stable. This stability in part has been due to the broader scale of operations of Central Norseman Gold Corporation N.L., and in these operations diamond drilling has played an increasingly important role.

Jan 1, 1956

By Sandy W

This paper examines the effects of a significant number of plant alterations and modifications to the lead flotation circuit during the past five years. Metallurgical effort is directed largely at the flotation performance of middling streams and current strategies are discussed. The automatic control of cell destination and collector additions are outlined in the latter section of the paper, along with a description of control hardware in current use.

Jan 1, 1983

The Mt Keith Operation, 90 kilometres north of Leinster in the north-eastern Goldfields of Western Australia, was commissioned in October 1994. Based on a large tonnage, low-grade nickel sulphide orebody the plant was designed to produce 28 000 tonnes of nickel in a high-grade 20 per cent nickel concentrate. Following a successful and rapid start-up the operation is currently expanding to a throughput of ten million tonnes per annum (mtpa) ore and an annual production of 42 000 tonnes of nickel. This paper provides an overview of the Mt Keith Operation from commissioning to its present operation and Expansion.

Jan 1, 1996

By Yokozawa K, Yamamoto T, Kameoka Y

Japan Construction Method and Machinery Research Institute has been conducting various field surveys of tunnel works and other excavation works, and the cost and efficiency of these two excavation methods have been studied. Based on these data, the costs of blasting excavation and mechanical excavation represented by roadheaders were calculated. The costs were calculated and compared for rocks of various hardness. When the total construction cost is considered, the degree of overbreak becomes one of the most influencial factors, because the overbreak area must be filled up with expensive shotcrete in NATM. So, in the next step, the relation between the excavation costs considering overbreak and the rock hardness was studied using the data on overbreak obtained by the field survey.

Jan 1, 1987