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By Hindmarsh G

The colliery is owned by the BHP Collieries Proprietary Ltd., the principal shareholders being the Broken Hill Pty. Company Ltd. and Hebburn Limited.It is situated due west of Newcastle and 6 south-east of Cessnock, N.S.W., and is conneeted by 36 miles of railway to the port of Neweastle. Of this mileage, 3 miles are owned by the Company, 3 by Hebburn Limited, 9 by the South Maitland Railways Ltd., and 21miles by the Government Railways.The seam worked is known as the Main Greta Seam of the Greta Coal Measures and is on the southern slope of the Lochinvar anticline.At the shaft, the seam is 1190 ft. below the surface, and the section of the coal measures is:-Upper or Main Seam, . 24 ft. 0 in.Conglomerate and shale 70 ft. 0 in.'Middle Seam 8 in.Conglomerate 25 ft. 0 in,Bottom Seam 1 ft. 2 in.These lie between two marine measures, and are the lower coal series of the permo-carboniferous period.Only the upper seam is workable in this area, the lower seams being too thin for eompetitive working. The section of the workable seam at the shafts is as shown on Fig. 1.Unfortunately, only the lower 12 ft. 5 in. of the seam is saleable.

Jan 1, 1935

The Bendigo goldfield is centred on the urban area of Bendigo (population approximately 60 000) in central Victoria, 130 km north west of Melbourne, Australia. Gold was discovered at Bendigo in 1851 and production continued through to 1954. The Bendigo goldfield is the second largest goldfield in total gold produced in Australia, after KalgoorlieÆs Golden Mile with a total production of 22 million oz. The geology of the Bendigo Field consists of a series of tightly folded, interbedded sandstone and shale sediments. Within the sediments the gold mineralisation is hosted in quartz reefs or ribbons closely associated with anticline axes and reverse faulting. The gold within the quartz reefs is typically both coarse grained and erratically distributed.

Jan 1, 2002

By Martins V, Dunne R

A re-evaluation of the Hampton Boulder prospect in the early eighties resulted in a decision to proceed with mine development in December 1985. A 500 000 tpa gold treatment plant was commissioned in December 1986. The treatment facility was expanded to 1 600 000 tpa in July 1988. A tailings treatment plant to improve recoveries from harder gold bearing sulphide ores was built in December 1990. The development of an underground mine in 1991 meant that a source of sand for backfill was required. A sands plant to fulfil this requirement was commissioned during November 1991.As of June 1992 a total of 7 710 487 tonnes of ore have been treated through the New Celebration gold plant. Total gold production from inception of the new mine until June 1992 is 545 470 ounces obtained at an average recovery of 90.1 per cent from an average gold head grade of 2.4 g/t. The combined quoted ore reserves at the end of December 1991 was 14Mt grading 1.8 g/t gold

Jan 1, 1992

By Lemberg D. W, Friday R. G

Potential means of lowering overall costs to permit deeper stripping include : 1. the use of larger diameter blastholes in highly-fissured strata (to reduce drilling costs); 2. dewatering from semi-permanent bores to reduce blasting costs (by maximising the use of bulk ANFO) and promote highwall stability; and 3. the use of inclined blastholes, bulk AN, staggered V1 patterns, adequate backfill and more cost-effective stemming columns. Each of these is covered. The pumping of bulk watergels continuously raises the blasthole water column, thereby perpetuating the demand for these blasting agents. This must be a principal consideration when choosing between a bulk and a packaged watergel. Any packaged product should exhibit dimensional permanence and an energy yield per metre length equal to that of bulk ANFO. Possible ways in which controlled trajectory blasting (CTB) could benefit deeper stripping operations are outlined. By allowing the maximum use of bulk ANFO, de- watering may be a prerequisite of a viable CTB Operation.

Jan 1, 1981

There is a difference in design aspects between steel linings and rubber linings for grinding mills. The basic design rules for rub- ber are described as well as the liner designs for different applications.

Jan 1, 1978

By L Richards, R L. Brathwaite, C Mazenga

Underground mining of gold-silver bearing quartz lodes was carried out in the great mines at Martha Hill, Waihi over 70 years from 1882 until 1952. Shafts and stopes reached a total depth of 600 m on 16 levels, with workings extending laterally some 1.6 km, and as new reefs were discovered the workings extended beneath parts of the township. Over their long life the mines produced 1217 tonnes of gold-silver bullion from processing 12.2 million tonnes of mined ore. In the early-1980s drilling proved large reserves of gold and silver ore remaining in stock-work zones between the previously mined lodes. This led to a new era of mining at Waihi with the opening of the Martha Hill open pit in 1988. A series of three sink holes have formed above unfilled stopes of the Royal lode. In 1999 a sudden collapse crater 40 m in diameter occurred near an occupied part of Waihi, placing in danger several houses and a busy street. This crater formed close to a similar crater that occurred in 1961. The 1999 collapse resulted in subsurface investigations and risk assessment studies being commissioned by the local Hauraki District Council. However, a further 50 m diameter collapse crater in December 2001 formed in a residential area, swallowing and wrecking an occupied house, fortunately without injuring its five occupants. Two other houses were perched on the crater rim. The 2001 collapse led to an acceleration of the work being carried out by the Institute of Geological and Nuclear Sciences Ltd. (GNS) to identify the extent of the old underground workings at Waihi. For the risk assessment detailed rock mechanics analyses were made to consider the stability of the underground mine stopes, in terms of the stope back, hangingwall, footwall and crown pillar failure mechanisms, as well as void migration. The collapse crater areas were analysed using using several methods, including analysis to simulate the probability of void migration from unfilled stopes to the surface using the @Risk program. The analyses show that in the cases of the actual collapse craters, the voids have a high probability of migrating to the surface, thus providing a method of testing the void migration modelling. Modelling analysis applied to the remaining stopes of the old underground mines show there are further areas where void migration from unfilled stopes has a high, medium and low probability of reaching the surface as a collapse crater. The locations of these probabilistic hazard zones were outlined using the @Risk modelling and deterministically by using the dimensions of the historical collapses applied along the length of the stopes. Consideration of the æincubation periodÆ (the time interval between the cessation of mining and the occurrence of collapse) and comparisons with mine subsidence histories overseas, indicates that further collapses are likely to occur over the next 50 years. Risk assessment estimates made using property values and occupancy levels within the three hazard zones, were compared with Societal and Individual Risk criteria. Results indicate that safety within the high and medium zones may be unacceptable.

Jan 1, 2003

By Sorokin M, Komkov A, Fyodorov A

The Vanyukov Process is a high-intensity smelting system that has been proven over the last 20 years for various metallurgical operations including the smelting of copper, nickel, copper-zinc, antimony concentrates, municipal waste treatment and pig-iron production. Extensive pilot plant tests on copper and copper-nickel concentrates have provided information for the design of the commercial furnaces. The thermodynamic analysis, design idea and the data obtained from commercial furnaces have shown that Vanyukov Process would be the best choice to smelt copper-nickel and nickel sulphide concentrates as well as oxide nickel ores.

Jan 1, 1996

Broken Hill is situated at an elevation of approximately 1000 ft. above sea-level, on the Barrier Ranges, in the State of New South Wales, Australia. It is approximately 700, 280 and 330 miles from the ports of Sydney, Pirie, and Adelaide, respectively.The summers are usually hot and dusty, with a recorded maximum shade temperature of 114° F. The rainfall averages approximately 9 in. per annum.

Jan 1, 1932

By McMahon DW

The major components of a mineral reserve estimate for project development purposes are described with respect to sampling, geology, estimation methods, mining factors, metallurgical factors, environmental factors, financial and other factors. Each of these components impact to varying degrees on the recoverable metal or product of a new mining project. The evaluation of a project is a complex process involving the best the profession can provide in terms of geological understanding, engineering ingenuity, metallurgical skills and financial evaluation.

Jan 1, 1983

By Enever J, Walton R, Wold M

Photoelastic and equivalent material model ling techniques for studying stresses and defor- mations and modes of failure in geological and engineering structures are described. The appli- cation of these techniques to the solution of tunnelling design problems is outlined. Models may contain heterogeneous components to simulate geological and man-made structures and may be two- or three-dimensional. Prototype construc- tion procedures and time dependent behaviour may be modelled. Examples of recent model studies carried out for the design of underground railway tunnels are given. Development of photoelastic and equi- valent material modelling techniques and facili- ties at the CSIRO, Division of Applied Geomech- anics are described, including a biaxial and triaxial frame for testing large scale two and three dimensional equivalent material models and components of full scale prototype structures.

Jan 1, 1976

By Takasaki Y, Ohzeki S, Hotta H

TO measure high temperature properties of blast furnace burdens ( the change of gas permeability accompanied by contraction, soft- ening and melting ) which govern the gas flow and its distribution, a series of experiments were carried out under simulated blast furnace conditions, using sinter, acid pellets and self -fluxing pellets. 1) The high temperature properties are affected by the ore's reducibility ( up to 1000 -1200¦C ), and the composition, and volume of gangue before reduction. Generally, the burde- ns with high basicity ( Ca0/Si02 ), high reduc- ibility and low volume of gangue have good high temperature properties. Good high temperature properties are : a high temperature at which the gas permeability rapidly decreases, a high melting point and a low maximum pressure drop. 2) Using acid pellets, slow-down of red- uction rate occurs around 1000¦C because the pellet forms a dense metallic shell, while its slag core, resulting from a FeO, Si02 and A1203 reaction, has a lower melting point. 3) The addition of MgO sources improves high temperature properties both of sinter and Pellets.

Jan 1, 1980

This paper describes the application of a three-dimensional finite element modelling tool to help assess the stability of a highwall at a Central Queensland mine following the weakening of its base due to highwall mining. With traditional stability assessment techniques, likely failure modes are identified on the basis of previous experience and structural, sedimentological and geomechanical data and a mechanistic analysis of these individual modes is performed. The value of the full three-dimensional model over these traditional techniques is that it provides a coherent approach to assessing highwall stability without the necessity of initially deciding upon the dominant failure mechanism and gives a useful adjunct to the traditional tools. The three-dimensional model assumes the rock mass is made of elasto-plastic blocks, incorporating possible planes of weakness, separated by near horizontal joints. The model includes the relaxation of stresses due to the excavation of the highwall and incorporates estimates of blast damage near the highwall surface

Jan 1, 1995

By Glassock C. D

Most Australian mining projects are becoming smaller, more remote and with lower grades of ore. Their small size has been making it harder for mining companies to absorb the large infrastructure costs. This has forced companies to reduce those costs in every way they can. Social factors, environmental groups and even tax laws have added other pressures to force down the infrastructure costs for remote projects. For the last ten years, the downward trend in costs has been marked. It seems certain to continue for years into the Future.

Jan 1, 1997

In order that the processes seen may be followed in their proper 'order, the subject will be dealt with as follows, (1) Wallaroo and Moonta Mines; (2) Wallaroo and Moonta Mines Smelting Works; (3) Broken Hill Mines; (4) Concentration at Broken Hill; (5) Smelting and refining of Lead, Silver, and Gold at Port Pirie. The first acquaintance with the copper region was made at the Yelta shaft and dressing mill of the Parramatta Copper Mines Co. at Moonta. The country rock at Moonta is a hard, tough, felsitic porphyry, the copper lodes having a general strike of N. 30° Kilipping from 500 to 70°. This necessitates shaft-sinking on the lode, and underlay shafts are the rule on the field. The ore is raised in the Yelta shaft in wheeled skips, and consists of ·chalcopyrite, bornite, pseudomorphic hematite, containing, in addition, molybdenite and tourmaline. The ore from the bins at the brace is passed over a grizzly; the over-size is hand-picked into smelting ore, concentrating ore, and waste rock (00 attle ), which is sent below for filling. The under-size is elevated to a trommel having in. holes. The over-size falls on to a picking belt made up of lengths of rope strapped with iron, working over wooden pulleys.

Jan 1, 1907

By Gyasi-Agyei Y

In recent years rapid advances have been made in the technology used for hydrology and erosion modelling of rural catchments. These advances have been driven by the growing availability of digital terrain maps that can be used to automatically define catchment properties that previously had to be manually extracted from contour maps. In addition, these models have, in principle at least, more powerful predictive capability. The author is involved in a number of projects to migrate and further develop these models for application to mine rehabilitation assessment. Current technologies for hydrology and erosion assessment (eg CREAMS, ANSWERS) are reviewed, underlying principles highlighted and deficiencies in the context of mine rehabilitation design assessment addressed. The advantages and disadvantages of the new digital terrain map tools (eg WEPP, SIBERIA) are discussed. Current work integrating these new models with existing rehabilitation design tools (eg ACIRL's ARGUS computer package) highlights the advantages of an integrated approach using digital terrain maps; cheaper, faster, lower impact and more flexible rehabilitation design. The use of novel visualisation tools to aid the design process is discussed. The paper is illustrated by applications to mine sites in Queensland and the Northern Territory.

Jan 1, 1995

By H Catchpole, L FontbotT, J PTrez, M Ageneau, A Bendez·

In the world-class mining district of Morococha, epithermal polymetallic replacement bodies and veins overprint porphyry mineralisation and skarns related to subvolcanic intrusions of Miocene age, thus indicating ore formation in two different environments, separated in time or forming a continuum. The district covers an area of about 70 km2 in the north-western part of the Domo de Yauli complex in theWestern Cordillera of central Peru and is part of the Miocene polymetallic belt, also hosting the deposits of Colquijirca (Bendez· et al, 2008b) and Cerro de Pasco (Baumgartner, FontbotT and Vennemann, 2008). Multiple late-Miocene porphyry stocks intruded Permian, Triassic-Jurassic and late-Cretaceous sedimentary carbonate and volcano-sedimentary formations, as well as large mid-Miocene barren intrusions. Extensive field work and detailedmapping of different styles of orebodies suggest that ore formation in the area was related to the late-Miocene magmatism. Good outcrop conditions and superimposing of different mineralisation styles make Morococha an ideal location for studying ore-forming processes in a complex porphyry-related magmatic-hydrothermal system in which porphyry-to-epithermal transition occurred. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

1991 New Zealand Branch Annual Conference û Appendix

Jan 1, 1991

By Hedge AS

Mt Whaleback is one of the largest open-cut iron ore mines in the world. Haulage cost is the single largest component of operating costs at the mine. Past studies towards alternatives to truck haulage have recognised the potential viability of an in-pit crushing and conveying system, dependent on the proportion of uphill haulage. After seventeen years of mining Mt Whaleback still contains more than 1,000 million tonnes of ore, needing 1,800 million tonnes of waste removal to extract it. What was once a quarry has now turned into a large open pit. The increasing proportion of uphill haulage, the need to replace ageing 120 ton and 200 ton trucks and the necessity of achieving and maintaining a higher stripping ratio prompted, in 1984, the initiation of a new feasibility study into the viability of alternative material handling systems. A semi-mobile in-pit crushing and conveying system was found to be most suited to Mt Whaleback conditions. The East Pit was selected as the best location based on the analysis of haulage profiles measured on long term incremental mine plans. A capacity of 22 million tonnes per year was considered achievable by the proven technology currently available. A detailed estimation of capital and operating costs of two systems - one with trucks only and another with trucks, crusher and conveyor - for the removal of 22 million tonnes per year of waste rock, showed substantial cost savings achievable by the proposed system. An economic evaluation of the two systems established the advantages of constructing the in-pit crushing and conveying system. This is now under construction and will be commissioned in early 1987. Experience gained in constructing and operating this installation is expected to influence decisions on similar installations in future.

Jan 1, 1986

By Le V, Nguyen Ngoc Quynh, R H. Murfitt

The Truong Son Fold belt in Indochina hosts the significant Sepon gold-copper district (Laos) and the similar gold-basemetal districts of Phuoc Son and Bong Mieu (Vietnam). With over seven years of exploration, Toronto-listed Olympus Pacific Minerals Inc, is one of few foreign companies that have to date made a substantial investment in mineral exploration in Vietnam.Much of this work has been conducted along the Phuoc Son û Tam Ky Suture, on the south-eastern limb of the Truong Son Fold belt on the Vietnamese side of the border with Laos. These programs have produced a significant number of gold prospects at varying stages of exploration development. The Phuoc Son û Tam Ky Suture is a major Paleozoic subduction zone that extends from northern Laos, through Central Vietnam and out into the South China Sea.It represents a Lower Mesozoic collision zone between the Paleozoic-age Truong Son fold-belt terrain to the north, with the crystalline terrain of the Pre-Cambrian Kontum Block to the south. Since its formation, it has been a locus of deep faulting, continental accretion, intensive intrusive activity and mineralisation. This paper briefly discusses the geological setting, structure, metamorphism, mineralisation, exploration history, and proposed mining development of the Olympus Phuoc Son Gold Project, with particular reference to the Phuoc Son û Tam Ky suture.

Jan 1, 2004

By Hamblyn S

Oakbridge, in combination with its joint venture partner, Nippon Steel of Japan, is expanding its Bulga underground and open cut mines to meet the growing demand for coal in the Asian market. Expansion works underway will see the Bulga underground mine become a world leader in underground productivity, the introduction of a high capacity dragline into the open cut mine (largest capacity dragline in NSW) as well as a major upgrade of the coal preparation plant (CPP) and coal handling facilities (CHF) to process the increased production. This paper describes the planning and implementation of this major expansion program and highlights the rationale behind some key aspects of the program.

Jan 1, 1995