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By Lees M. G, Vitnell B. W

The post-war need to increase coal production promoted an intensive drilling campaign. Ineffectiveness in core recovery inclined the coal industry towards percussion drilling rather than diamond drilling. The Joint Coal Board, recognising the greater potential of core drilling, has actively encouraged improvement in techniques and equipment. One outstanding need was a barrel which, over and above other improvements being achieved, would permit recovered core to be examined before it had been subjected to the increased fragmentation and displacement which to date has been inevitable except in core which has been drilled in solid sticks û as New South Wales coal rarely can be drilled. In conjunction with Triefus Pty Ltd a barrel with a split inner tube has now been evolved, as a result of which, core can be more accurately logged, division in to lengths for analysis more aptly made, any core loss more reasonably allocated to appropriate plies, and a greater percentage of core recovered û of the order 95 per cent and more. The one half of the split inner tube is lifted from the other and the logging completed before the core is disturbed.

Jan 1, 1957

By R L. Brathwaite

The epithermal gold-silver deposits wall poster is one in a series of posters on different mineral deposit types being produced by GNS Science to raise awareness of the characteristics of New Zealand mineral deposits and their prospectivity. Epithermal deposits consist of quartz veins, quartz vein stockworks and hydrothermal breccias that are mainly hosted in subaerial andesitic or rhyolitic rocks of Tertiary age. The deposits were formed at depths of typically less than 1 km and at temperatures between 180¦ and 320¦C, although ore grade mineralisation was generally deposited at less than 270¦C.   In New Zealand, epithermal deposits occur in association with late Cenozoic volcanic rocks in the Northland, Coromandel and Taupo volcanic regions. All of the past and present gold production, estimated at greater than 380 t (along with 1300 t Ag) comes from the Miocene-Pliocene Coromandel Volcanic Zone, where about 50 epithermal gold-silver deposits occur over a 200 km long belt. In Northland, silver and mercury have been produced from hot spring type epithermal deposits, and several gold-silver prospects have been identified. Ore grade gold-silver mineralisation is currently being deposited in several active geothermal fields of the Taupo Volcanic Zone, and extinct geothermal systems occur on the western side of the zone. The active systems have provided natural laboratories to help understand the processes of epithermal mineralisation.

Jan 1, 2005

Wet mining of auriferous gravels at L & MÆs Waikaka operation in Southland creates spoil dumps derived from stripping of a clay rich overburden, tailings from past dredging and the processing of auriferous sands and gravels. Over recent times, spoil dumps have slumped on six occasions, threatening the viability of the wet mining operation. Close examination of slump morphology, coupled with the sequence of material placement and rate of dumping suggested a mechanism associated with undrained failure of a 2 m layer of silt and sand tails forming the base of dumps.Commencing with some information on the geotechnical properties of source overburden, back analysis of failure morphology and sequence and development of undrained loading conditions from first principals, the most likely failure mechanism and factors controlling failure were defined. Based on analysis results, a scheme to stabilise the lowwall dumps was developed and implemented, augmented by continuous monitoring of pore pressures in the basal wet tails, and laboratory testing for confirmation of computed material properties.Lowwall spoil stability has improved since implementation involving changes to the method of spoil loading, and modification of wet tails composition to improve permeability and drainage of the basal wet tails under load. The method and approach to prediction and verification of failure mechanism provide a sound basis for continued mining of deeper auriferous gravels.

Jan 1, 2002

By R Aseervatham

The fast tracked mine development strategy attempts to blend feasibility studies and engineering/commissioning functions into a streamlined process. In this compressed process, environmental issues are difficult to control with respect to the optimisation of operational environmental performance. This paper presents a standard mine development process with specific focus on environmental issues, and contrasts this against Rio TintoÆs recent fast track experiences on the Hail Creek project (Australia), the Baranj project (India) and the Gokwe North project (Zimbabwe).

Jan 1, 1999

By P M. Black, T Itaya

Arc-type volcanic activity has been a major feature of the late Cenozoic geological evolution of the Pacific-Australian plate boundary in the northernNew Zealand region. The time/space distribution patterns of arc-type rocks reflect changes in the nature of the plate boundary as it has evolved. Inception of volcanism began in the north during earliest Miocene times (26 Ma) following ophiolite emplacement and during the next 10 Ma developed into a volcanic arc segment extending south to the present position of the central North Island. The northern part of the arc became extinct about 15Ma ago, but activity continued in the central (Coromandel) part of the arc until about 5 Ma ago. In late Pliocene and Quaternary times volcanic activity has become concentrated in a northeast trending zone which is collinear with the Tonga-Kermadec Arc.   These time/space patterns can be interpreted in two ways. Firstly, if relative plate motion was essentially transform in the region prior to 26 Ma then a small change in the relative plate vectors may have initiated subduction and the associated volcanism. Southward evolution of the arc can then be seen as the straightening and extension of a single arc. Alternatively, the distribution of volcanic rocks can be interpreted as the capture of a relatively short lived arc by southward migration of the dominant Tonga-Kermadec subduction system.

Jan 1, 1995

By G J. Corbett, P Magner, M McKenzie

Structures formed during ductile deformation have been reactivated during the later brittle mineralisation process. Two generations of folding are classified as: early recumbent megascopic FI folds and FI shears which transpose the hinge regions, and later upright F2 folds. S1 is folded about F2 folds which contain axial planar S2 crenulation cleavage. Vergence relationships between S1 and bedding indicate that many of the mineralised structures occupy sites of FI folds which have acted as plumbing systems for later gold mineralisation (eg Blackwater mine). The Globe-Progress gold mineralisation is localised by a major jog formed by sinistral strike-slip movement on two FI fault segments and mineralisation also occurs in smaller jogs along strike (eg Sir Francis Drake, Happy Valley-Merrijigs, Cumberland).   The lodes of ribbon quartz which exploit the FI shears and local bedding planes, are inferred to have mostly formed after the peak of metamorphism, possibly related to the emplacement of Carboniferous granites. This was followed by a sequence of vein deposition and wallrock alteration which consists of quartz-As/Fe sulphides ? carbonate - stibnite ¦ trace base metal sulphides and Bi-sulphosalts ? illitic clay/sericite-chlorite. Gold at Globe-Progress is mainly encapsulated in arsenopyrite. At Blackwater, free high fineness gold occurs in partings in lode quartz with late sericite-chlorite. The above sequence of events is comparable to that encountered in many intrusion-related gold systems throughout the Southwest Pacific region. There is a spatial relationship between gold mineralisation and dykes variably described as diabase, dolerite or lamprophyre. Alkaline rocks occur in many Pacific rim and older goldfields and may possibly be related to a magmatic source for gold mineralisation.

Jan 1, 1997

How the Australasian and Canadian Codes (VALMIN and CIMVal) approach mineral property valuation is described. Brief comment is also made on the International Valuation Standards CommitteeÆs interest in a global valuation standard for Mineral (Extractive) Industries and the South African SAMREC initiatives to adopt a VALMIN-like Code. The conventional tripartite classification of valuation approaches into those that are Market-based, Income-based and Cost-based is outlined. It is best practice to use as many of these approaches as possible (and as many methods as reasonable in the particular circumstances), given the quantity and quality of the data available on the Mineral Asset (which depends upon the state of development of the mineral property). The use of specific methods must satisfy the basic considerations of logic and reasonableness and the purpose of the valuation. The competence, judgement and repute of the valuer are critical factors, since all valuations are time and circumstance specific. What constitutes æMarket ValueÆ in the different jurisdictions is discussed and definitions are given. Challenges facing the globalisation of a VALMIN-type Code for the international Minerals Industry are the influence of real estate valuers and the US jurisdictional idiosyncrasies. This is mainly due to a fixation on real property rights with a preference for using real estate-like comparative sales techniques (Market Approach) to the exclusion of Income-based approaches; a regulatory reluctance in the US to accept that Resources have considerable value; and the International Accounting Standards BoardÆs preference for Historical, rather than Current Value, accounting.

Jan 1, 2002

The Mineralogical Researches of Gold Ores and Technological Products at Operating Factory in Olympiada Mine (Russia)

Sep 13, 2010

Well designed and maintained haul roads are the key to minimising truck haulage on-road hazards and costs, as well as increasing productivity. However, practically designing and managing a haul road for optimal performance is often diff cult to achieve. Poorly designed and built roads exhibit high rolling resistance - a one per cent increase in road rolling resistance can typically reduce speed on ramp by as much as ten per cent - and on the f at by up to 26 per cent. In the current economic climates, investment and operating decisions come under scrutiny. In the long run, this scrutiny returns improved efficiencies and leaner, healthier operations. The focus of this evolving evaluation process should and will certainly fall on haulage operations - simply by virtue of their contribution to overall cost of operations - often in excess of 50 per cent of total costs for deep open-pit mines. Whilst the end result - improved efficiency and reduced cost per ton hauled - is not in itself problematic, it is the route, or process followed to achieve these savings that needs to be carefully managed. We can be guided on this journey by our understanding of how a road is designed, and, critically, the interplay between a good design and safe, cost efficient haulage.This paper brief y summarises the evolution of mine haul road design, from the seminal USBM work of Kaufman and Ault in 1977, through to current geometric, structural, functional and maintenance management design components. These augmented design and management guidelines have been developed over the past decade, both in response to the requirements of mine operators for more safe and efficient haulage systems, and the truck manufacturers' requirements for a more predictable and controlled operating environment. These developments have been paralleled by the need to minimise haulage hazards, both from a health and safety perspective. Generally, both objectives have been achieved, but with some specific areas of design and operation still presenting ongoing potential health and safety hazards.The paper then summarises current design guidelines for these safety-critical issues, both from a road-design 'best-practice' and road management perspectives. Implementation of the approach is seen as a basis for reducing the potential of an under-designed mine road to lead to health and safety defects and secondly as a means of giving haul road safety and performance issues greater prominence in the minds of the road-user, operator, mine planner and designer alike.

Dec 6, 2010

By D Wyatt, J Domenico, W Kow

Over the past few years developments in heavy minerals processing have concentrated on the mineral separation portion of the business. The best example of this would include new developments in rare-earth magnetic separators and associated flowsheet modifications. Except for some minor modifications in spirals, the æwetÆ side of the separation business has lagged behind the ædryÆ side. Basic concentrator design has not changed in 20 years. Recent pilot trials by Outokumpu Technology have shown the benefits of a new gravity flowsheet that combines density separation and spiral concentration on a variety of heavy mineral deposits. This concept is already well utilised within the iron ore industry. The synergistic combination of these two technologies allows smaller, simpler, and controllable gravity concentrators to be built while providing equivalent or better grade and recoveries of valuable heavy mineral. This is contrasted to the all spiral flowsheet characterised by the diminishing returns of multiple stages of spirals and associated recirculating loads. Examples of the flowsheets and associated benefits will be presented from a variety of cases.

Jan 1, 2001

Effect of Anionic Surfactant on Silica Particle Attachment at the Oil-Water Interface Controlling particle attachment is crucial where powdered solids come into contact with oil and water. Particles are trapped in a deep energy well at the oil-water interface, stabilising emulsions. Here it is shown that adding anionic surfactant causes dramatic changes to the bulk and interfacial structure of silica particle-stabilised oil-in-water emulsions. Exposing particle-stabilised drops to surfactant concentrations above the critical micelle concentration enhances the rate and extent of creaming and flocculation. Mixing particle-stabilised emulsions with surfactant solutions causes drop fragmentation. As the surfactant concentration increases, the average drop size decreases and particles are displaced from the interface during the mixing process.

Sep 13, 2010

By A Vigar

Siliceous float sampled in the Wafi River by CRA Exploration in 1977 assayed 22 g/t Au and 89 g/t Ag. Follow up in 1979 led to the discovery of outcropping mineralisation now known as Zone A. Soil sampling in 1980 and 1982 outlined a 350 m by 400 m area of >1 g/t Au at Zone A and smaller areas at Zones B, C and D. Thirty-one diamond holes were drilled between 1983 and 1986. Elders Resources continued evaluation of Zone A under a farming agreement between 1988 and 1990. Mineralised diorite porphyry was discovered in 1990 by drilling conceptual targets 500 m to the NE of Zone A. Evaluation of this copper-gold porphyry became the main focus of exploration for the next five years and a substantial resource was outlined within a single, discrete body. A review of the paths to project development in late-1995 highlighted the need for increased resources via a second mineralised porphyry and/or an additional resource of Zone A size to make the project viable. It was concluded that the greatest immediate potential for increasing the resource inventory was at Zone A itself where the mineralisation was open in all directions. Detailed mapping and drill core logging lead to the geologic and structural models being revised in early-1996. The objectives of the 1996 drill program were to extend the Zone A resource, to test for continuity of mineralisation westwards to Zone B, to better define the controls on gold mineralisation and to delineate high-grade blocks amenable to selective mining by infill drilling and 3D orebody modelling. The last drill hole of 1996 intersected 30 m at 4.6 g/t Au from 273 m in WR147, deep in the western limit of Zone A. This intersection gave impetus to continue drill testing towards Zone B. In April 1997, hole WR154 was drilled 100 m to the west of WR147 and intersected 20 m at 8.5 g/t Au and 70 m at 11.0 g/t Au at similar depths near the diatreme contact. Drill hole WR155 was then drilled 100 m to the west of WR154 and intersected 86m at 5.7 g/t Au and WR159 drilled 100 m to the south of WR154 intersected 36 m at 9.2 and 50 m at 4.4 g/t Au. A significant zone of essentially blind, high-grade gold was discovered beneath the dipping flank of a poorly mineralised diatreme in what became known as the Link Zone. The long history of evaluation has been driven by the conviction of a dedicated team that a mineralised system of the size and complexity of Wafi with strongly anomalous gold in outcrops over the entire Mount Golpu area must contain economic mineralisation hidden within it. The keys which redefined the direction of exploration and lead to the discovery of the blind, high-grade gold Link Zone were, in our view, the critical review of the project status, detailed geological and structural studies to define clear exploration targets and the necessary funding and persistence to carry this through.

Jan 1, 1999

By P Vasconcelos, X D. Deng

Numerous supergene manganese oxide deposits are developed inSouth China as a result of weathering of a thick sequence of Paleozoic marine Mn-bearing sedimentary rocks, consisting mainly of limestones, cherts and black shales that were intensely folded and faulted due to multiple episodes of tectonism since the late Triassic. The ore minerals are dominantly pyrolusite, cryptomelane, nsutite, lithiophorite and braunite. The supergene manganese ores contain Mn ranging from 20 to 44 wt per cent; manganese oxide deposits derived from cherts and black shales also contain recoverable levels of Co, Ni, Cu, Pb and Zn. 40Ar/39Ar dating of potassium-bearing manganese oxides reveals that extensive supergene manganese ore formation started at least in the earliest Miocene and persisted to the Present. Ages of the deposits show a close correlation to tectonic stability, with the oldest in tectonically quiescent areas and the youngest in active areas that have subjected to continuous uplift and thus significant denudation. The prolonged wet and hot climate since Oligocene and the balance between weathering and erosion, which is parameter to the tectonic stability, are the ultimate controls on the formation and distribution of South China supergene manganese oxide deposits. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Rogerson R, Queen L

The petrology and age of mid Cretaceous to Palaeogene marine volcanics may provide important clues to the palaeogeography of the period, particularly for tectonic elements and events outboard of the Papuan Basin. This initial survey of known marine volcanics of this age reveals a paucity of reliable data on isotopic ages, geochemistry and syngenetic mineralisation on virtually all units. Existing data allows a tentative subdivision of known marine volcanics into either MORB-like early Palaeogene rifts/ marginal basins, early Palaeogene ensimatic arc rocks overlying ?Late Cretaceous and Palaeogene fore-arc/marginal basin crust, late Palaeogene ensimatic arc rocks, and mid to Late Cretaceous ensialic rift rocks. Due to lack of data, some units are difficult to classify into these categories.

Jan 1, 1991

In 1976 the Pitjantjatjara Council was established under the Associations Incorporation Act 1985 (SA), for the initial purpose of organising and bringing together three similar Indigenous groups. These members of the Pitjantjatjara Council of Central Australia were demanding land rights and to legally protect their traditional lands. The Land Rights movement was more focused on the South Australian Government that became more receptive to the general notion that Aboriginal freehold land could be attainable.For almost five years, Pitjantjatjara CouncilÆs intense negotiations took place with the Dunstan and Tonkin Governments culminating in the final passage of legislation by 1981. A bi-partisan approach by Government and opposition applauded by all South Australians for its mature and socially responsible actions, in line with the Aboriginal Land Rights (Northern Territory) Act 1976 (Cth). Despite the similarities between South Australian and the Northern Territory Land Rights legislation, there still remains one obvious distinction. In the Northern Territory case, its legislation established æLand CouncilsÆ as statutory authorities that are responsible for the management and use of designated Aboriginal lands. On the other hand, South Australian legislation fails to include any reference to æLand CouncilsÆ as defined in the Northern Territory Act. The intention of establishing such æLand CouncilsÆ in the Northern Territory was, and is to provide legal, anthropological and other expect advisers that respond to the wishes and opinions of Traditional Aboriginal Owners. Negotiations between mining companies and Land Councils, will, after the granting of mining leases, monies are then transferred to those Councils being a percentage of royalty entitlements. While the Pitjantjatjara Land Rights Act 1981 (SA) (Act) does provide royalty arrangements to Anangu Pitjantjatjara (AP), a body corporate pursuant to the Act as a Landholding Body (and not as a æLand CouncilÆ), it does not provide any royalty payments for the legal and anthropological services by the Pitjantjatjara Council for providing essentially similar services as the Northern Territory Land Councils. The limited services by AP do provide complimentary services from other organisations û including the Pitjantjatjara Council. There are approximately 4000 Anangu members who reside on AP Lands and more than 1000 other Anangu members live near AP Lands in Western Australia and the Northern Territory. These people are defined as APÆs æTraditional OwnersÆ by virtue of their affiliation to portions of AP Lands. As a result, the depth and understanding of spiritual beliefs and customs are strongly present as it relates to the whole of the Lands. Most of these members reside at permanent communities that spread unevenly about the northern and south-western parts of AP Lands. In addition, there are numerous æHomelandsÆ where families and extended families have establish homes, with electricity and water supplies on those Traditional Lands (see Appendix 1 and 2 of this paper depicting the map showing AP Lands and also showing stunning photographs taken during late last year). All roads and airstrips are unsealed between communities and Homelands and the essential services to all communities are limited and costly to provide, and require continuous upgrading. Capital expenditure on infrastructure is sorely needed and alarming levels of unemployment is of serious concern. Tjilpi (older) Anangu members have continually discuss the urgency to provide employment and education for the future of their children and grandchildren while balancing the needs of maintaining cultural and spiritual considerations. It is thus a growing realisation by many Traditional Owners that long-term benefits occur as a result of exploration and production of oil or minerals. There are promising results from Primary Industry and Resources of South AustraliaÆs (PIRSA) Aero-magnetic Surveys on the Musgrave and Mann Ranges and soon to be completed surveys of the remaining southern half of AP Lands (see Appendix 3). PIRSA and mining companies û such as Rio Tinto Exploration Pty Ltd and Delta Gold NL û have been more conscious of the necessity for improving the dissemination of information to Traditional Owners and to AP members. With recent findings of large nickel deposits just over the border in Western Australia, there is a strong indication that discoveries may occur on AP Lands as similar geological information is present on the east Musgrave Block. Consequently there are concerted efforts by the legal and anthropological services of the Pitjantjatjara Council to arrange Workshops and Summit meeting to give extra information û particularly information concerning the true effect of large-scale mining operations û to members to properly consider these proposals. Pitjantjatjara Council will play a major role in any decisions effecting Traditional Owners and AP, and will ensure orderly and professional services when dealing with legal, cultural and sensitive matters. This paper addresses the historical and current relationship between Pitjantjatjara Council and AP, with an emphasis on mining operations on AP Lands. It argues that future economic and social development on AP Lands hinge predominantly on the legal recognition of the Pitjantjatjara Council for its ongoing role, responsibilities and protection afforded to AP and its Traditional Owners.

Jan 1, 2002

This paper describes the excavation of No. 1 Power Station Lift Shaft at the Kiewa Hydro-Electric Project. The advantages and limitations of the borehole method are outlined, and general principles of plant design are discussed.INTRODUCTIONFor many years, attempts have been made to reduce mine development costs by various methods. Some of the, techniques of tunnelling have been adopted in horizontal headings, and in main vertical shafts, mechanical plant has displaced hand labour with notable success. However, in the field of small rises and winzes, improvements have largely been effected by attention to details of procedure. The most promising avenues for' substantial reductions in cost relate to:(a) Long-hole drilling(b) The borehole method(c) Calyx drilling.Whilst each of these methods has its peculiar advantages, the borehole rising method is probably most useful, and capable of wide application.In brief, the borehole method of rising requires a, drill hole parallel to the axis of the rise. A hoisting rope is passed through the borehole, and is attached to a platform on which the rising crew are raised with their equipment to the drilling position in the rise.When properly planned, the method is particularly safe, and has generally received the approval of mine inspectors and safety authorities. Rising work is generally hazardous, even when special timbering methods are used. In...

Jan 1, 1959

By R Byrnes, P Hensley

The outstanding environmental management initiatives undertaken by Novacoal at its Western Main Site near Lithgow in New South Wales over the past five years are detailed in this paper. These initiatives have been based on a combination of proven and innovative investigation and implementation techniques, close consultation with regulatory authorities and full support by colliery management. The results of these initiatives have enabled the colliery to exceed its pollution control obligations from a base well below industry standards. The initial poor condition of the mine was the result of over 50 years of traditional mining which paid little regard to environmental management. The transformation of the colliery within such a short period, with limited capital, is considered a model for the N.S.W. coal industry.

Jan 1, 1995

The Significance of Internal Recycle in Froth Flotation

Sep 13, 2010

By B B. Du, Y N. Lu, L X. Wang, S L. Wu

The cohesive zone in the blast furnace is largely affected by the softening and melting behaviour of ferrous burden because of its vital role in the blast furnace process. The Visual High Temperature Methodology (VHTM) has been given to study the softening and melting behaviour of sinter, two kinds of lump ores and acid pellet intuitively. Before softening, both two kinds of lump ore swelled and more serious for lump ore B because of its denser structure than lump ore A. The softening and melting temperature intervals are different from one another and this phenomenon contributed to the gas permeability of ore layer in the cohesive zone since the ‘ore window’ has formed. Besides, the softening and melting behaviour of mixed burdens have been studied, where it has been found that the softening and melting characteristics of mixed burden A (consisting of sinter and lump ore A) is better than mixed burden B (consisting of sinter and lump ore B) and mixed burden C (consisting of sinter and acid pellet) despite the poorest characteristics of lump ore A. The reason is that the high temperature interactivity between lump ore A and sinter is much better than lump ore B and acid pellet. The high temperature interactivity is mainly influenced by the chemical compositions, porosity and contact condition. This paper provides a new research method for the softening and melting behaviour of iron ore and an important technical basis for the optimisation of blast furnace burden.CITATION:Wang, L X, Wu, S L, Lu, Y N and Du, B B, 2017. The softening and melting behaviour of single and mixed iron ore burdens, in Proceedings Iron Ore 2017, pp 605–610 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

The use of walk-through inspections, approvals and ad hoc investigations to ensure risk is kept within acceptable levels is reaching its limits of effectiveness. Further improvement in occupational health and safety requires a systems approach, and the use of Quality Management principles is an obvious basis for this. SafeGuard, a æbest practiceÆ model health and safety management system and audit criteria based on AS/NZS ISO 9001:1994, has been produced by the Department of Mines and Energy. Quality style audits of mine and quarry health and safety systems are now being carried out by the Inspectorate.

Jan 1, 1998