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By U Briem, R Verreet

The level of wire rope technology used in mine hoisting applications has a significant effect on the overall efficiency of the hoisting system. This paper discusses the effect that a reduction in rope mass per unit length and an increase in rope breaking strength can have on rock skip capacity and hence mine shaft output. A 20 per cent reduction in rope mass per metre for a typical 48 mm hoisting rope, while maintaining the breaking strength, increases the skipÆs capacity by circa 30 per cent at a suspended rope length of 3000 m. Such gains in shaft output, without any significant changes to the shaft or winder design, can have major implications for the feasibility of future deep mine projects. The technical challenge for rope manufacturers is how to get rid of 20 to 30 per cent of the rope mass while keeping the breaking strength and modulus of elasticity of the whole rope constant. CASAR are currently developing steel wire rope constructions where the steel IWRC has been replaced with high strength, high modulus fibres such as Kevlar«, Spectra« and Dyneema«. One of the key aspects of such composite rope designs is to ensure equal load sharing between the different rope components, ie in proportion to their area. If there is a significant difference in modulus between the fibre core and the steel outer strands, the core may not carry its proper proportion of the load and the outer strands would be overloaded. Some technical aspects of the design of composite steel wire ropes are discussed. A design and operational issue that needs careful consideration is the safe non destructive testing (NDT) of composite ropes. Traditional magnetic NDT would only be capable of inspecting the steel wires. Techniques therefore need to be developed that would give operators a reliable indication of the condition of the load bearing fibre core. This paper also discusses possible solutions to this very important NDT question.

Jan 1, 2005

By B, T Norgate, S Sanetsis, R Davidson

Global cement production accounts for about five per cent of man-made CO2 emissions (WBCSD, 2002). Such operating practices will increasingly be considered unsustainable, unless significant reductions in environmental impact can be realised by the industry.Slag is a high volume waste product from ironmaking, with about 300 kg of slag being produced per ton of iron. Critically, one ton of slag waste, if used as a replacement feedstock for Ordinary Portland cement (OPC), can prevent around one ton of emitted CO2 since no calcining is required. Slag cement blends can also show superior properties compared to OPC, such as lower heats of hydration and higher late strengths, but more development is needed to overcome their low early strengths. Rapid quenching of molten slag is required to produce æhydraulically-activeÆ binder when reacting with OPC; but water quenching can also require between five to ten tons of water per ton of slag at the plant. æDryÆ granulation (atomisation) is emerging as an alternative technology, the resulting solid product does not require drying, and possibilities exist for recovering heat energy from the hot slag.CSIRO Minerals has well-developed skills and equipment in pilot-scale pyrometallurgical treatment, and granulation of molten slag, including traditional wet, and also dry methods. Techno-economic desktop studies can also be used to help quantify factors such as value-adding of treated waste products, potential reductions in CO2 emissions and carbon credits, reductions in water consumption, and the possible decreased energy costs associated with fine grinding of dry slag granulate.The authors will present preliminary results from slag atomisation/dry granulation testwork (0.5 - 2.5 kg scale) and associated modelling studies, conducted using a æsyntheticÆ and industrial ironmaking slag. Outcomes from a techno-economic study on production of cement utilising wet or dry atomised slag granulate will also be discussed in detail.

Jan 1, 2004

By C Reed

Titaniferous magnetite deposits are a significant source of vanadium for use in high strength steel alloying and other chemical applications. The mineralogy of the deposits varies markedly and the ore characteristics strongly influence the process route selected and the metallurgical outcomes. Characterisation of the ores reveals the presence of magnetite, ilmenite and other minerals such as spinel hematite and goethite with variable degrees of weathering along with weathered products of host rock. The standard processing route is to crush, grind and magnetically recover a concentrate for salt roasting to produce a soluble vanadate. Ore beneficiation is practised to generate an iron based mineral concentrate containing much of the vanadium with low silica levels of two per cent. Typical processing problems encountered are fine liberation size, over grinding of the magnetite and variable response to magnetic separation resulting from the weathering profile. Beneficiation options are restricted, and generally focused on producing a combined iron and titanium rich concentrate containing vanadium due to the fact that ilmenite and magnetite and their products of weathering are magnetic and have similar specific gravities making their separation difficult. The ilmenite usually contains low levels of vanadium making its separation highly desirable from the iron mineralisation containing higher levels of vanadium. Salt roasting of vanadium ores followed by water leaching has been the standard processing route for many years. The cost of suitable sodium salts, availability of capital and increasing energy costs and energy availability are critical factors in determining the viability of aspiring vanadium producers. To date, only Windimurra has acquired full capital funding, secured energy and sodium salt supplies at suitable cost that enable the construction of the project. Low overall recoveries of vanadium to concentrate roasting at up to 1200¦C are critical cost issues. In this paper, factors influencing the recovery of vanadium are reviewed and emerging processing trends explored. The important features of the processing of titaniferous magnetites have been condensed from the literature, published works, company websites, our own work and personal communication.

Jan 1, 2008

By M A. Etheridge

The evolution of economic precious metal and copper-gold deposits in high-level igneous terranes is dependent on very efficient fluid focussing. This is most readily achieved by contemporaneous deformation, igneous intrusion and hydrothermal activity. Mineralisation in these environments generally occurs in fault and fault-vein arrays developed in the cover sedimentary and volcanics sequences above older regional scale fault systems. Such reactivated fault systems are particularly prone to developing tile complex fracture arrays, extreme local dilation and dramatic increases in permeability that are necessary to efficiently focus hydrothermal fluid and produce large mineral deposits. The arc systems of tilePacific rim are typically structurally and tectonically complex. At any given period in the evolution of an arc system, it may be dominated by extensional, compressional or strike-slip deformation. Indeed, it is common for the tectonic environment to change repeatedly through the development of a single arc segment. As a result, structures formed in one tectonic environment are commonly complexly reactivated in quite different environments later in arc evolution. These complexly reactivated structures have greater potential to localise extreme fracturing, dilation and fluid flux than primary structures. Application of this knowledge to practical exploration requires an understanding of the primary geometry of the controlling fault systems, the fault movements during reactivation, intrusion and mineralisation, and the consequent location and geometry of dilational sites. Simple 2D lineament analysis and targeting on lineament intersections does not suffice. Chemical processes that results from structurally focussed fluid flow may also contribute to permeability enhancement and further enhance fluid flux. Two main types of chemical feedback are important. The first involves selective dissolution of minerals during alteration and tile consequent production of increased porosity and permeability. The second occurs where alteration changes the mechanical properties of tile rock mass, especially where it leads to a greater propensity for fracture (eg by silification). In near-surface environments (< ~1 km), geomorphic processes complement fault systems in focussing fluid flow to develop sub-horizontal bodies of mineralisation, such as the giant Ladolam gold deposit (>42 million ounces of gold).   Along with classification schemes which stress crustal level, host rocks and alteration assemblages, the styles of high level 'epithermal' and reated deposits must also be considered in respect of their controlling co-active fault structures. Such structural understanding, combined with understanding of tile chemical processes involved (eg host rock reactivity), provides a major tool for exploration particularly in terrains obscured by deep weathering. Geological interpretation based on integration of field mapping with magnetic, radiometric and other remotely sensed imagery provides a powerful complementary tool to the traditional geochemical and geophysical targeting techniques. Timely and effective geological input is capable of reducing exploration risk and providing a more cost-effective basis for drilling and development. Examples of deposits associated with fault reactivation in extensional, compressional and strike-slip settings within arc systems are discussed in this context.

Jan 1, 1995

THE slide-rule, as a quick and convenient instrument for performing approximate calculations, is steadily growing more and more into favour with the engineer, and results obtained by it are considered close enough to enable him to satisfactorily dealwith a considerable portion of his work. To the surveyor, however, whose ordinary computations must be as precise as his measurements, the present makes of rule are insufficient, except for a very narrow margin of the scales and for rough work. Few will carry the rule when they can clearly see that it is unreliable for general routine, and the careful surveyor is inclined to look askance at those who do use it, recognizing the temptation there undtmbtedly must be to push it into work that the log book should be called upon to treat. From the fact that a surveyor's duties take him on the surface in all weathers, and underground in many wet and uncomfortable places, where the manipulation of a book of mathematical tables becomes both awkward and patience-trying, an efficient slide-rule must offer the mbst transparent advantages. Again, a surveyor being specially trained to read divided scales quickly and accurately, the slide-rule must commend itself as an apt addition to his outfit.

Jan 1, 1912

By Tapp B. A

To date, few studies have been made regarding the energy requirements of the Australian mining and mineral processing industries. This paper indicates that these industries use a substantial proportion of the total Australian energy input (32.7% in 1971-72 and 36.10% in 1974-75). With the growth orientation of these industries, this input is likely to increase. Data shows that mining energy requirementE varied from 4.22% (of total Australian energy requirements) in 1971-72 to 4.16% in 1974-75. Energy requirements for the total mineral processing industries increased from 28.49% to 31.93% for the same period. The total estimated primary energy input varied from 22.56% to 25.2%, whilst indirect energy use, in the form of electricity increased from 10.16% to 10.66%; in the same period. Analysis of primary energy input data within the processing industries (1973/4) showed that the Iron and Steel Industry consumed 15.03% of the Australian total consumption, Non-Ferrous metals, 5.43%, Cement, 1.64%, and Refractories, 1.59%. In toto this represented 24.57% of the total

Jan 1, 1979

By R R LARGE

In the past decade mineral deposit models have become an important tool for the exploration geoscientist. By combining genetic theories on the formation of particular deposit styles, with geological, geochemical and geophysical criteria relevant to ore location, it has been possible to more effectively focus exploration effort to the regions and local targets which have the best chance of success. However, such models have their limitations, and must be carefully and critically applied and continually updated as new technical and research information becomes available.

Jan 1, 1992

Standard petrographic profiles for many Permian seams from New South Wales and Queensland have been drawn up. The standard profiles of seams of the same age and from one or more coalfields were used to compile an idealized or type seam sequence for those coals in which more than half the seam profiles were similar to one another. A marked similarity existed between at least 7 of the 10 type seam sequences formed.The configurations of the vitrite-plus-clarite contents of the plies of 95 per cent of the seams could be formed from different arrangements of 3 basic sequences. These were...

Jan 1, 1970

This paper discusses design concepts in planning a large modern bulk terminal. The need is emphasised for a studied master plan, in-built materials handling flexibility and staged development. An integrated approach is advocated, combining functional purpose designed foundations and structures to serve their mechanical, electrical and environmental functions. Dry bulk and slurry handling are also compared in perspective.

Jan 1, 1983

By Sen G

An amount of explosives, whether it be cylindrical, spherical, etc in configuration, with a hollow cavity in one face or end is known as a hollow or shaped charge. When this charge is initiated, a focussing of explosive energy will occur within this cavity. This focussing, or concentration of detonation products creates an intense localised force greater than just the simple detonation of a conventional explosive, (without a hollow cavity). If this hollow cavity explosive is directed against a target material this concentrated force is capable of creating a deeper penetration than the same amount of explosive without the hollow cavity. If a metallic liner material is used in the hollow cavity, upon detonation of the explosive this liner will form into a high velocity penetrating jet. Depending on the explosive type and the liner material's configuration the jet tip can travel up to 10 km/s. Linear shaped charges were developed using the abovementioned shaped charge concept but instead of being formed about an axis, they are elongated and constructed along the principal axis. Therefore instead of creating a narrow circular penetration jet, it forms a thicker planar cutting jet ideal for linear cutting purposes. Using Linear Shaped Charges (LSC) for pre-splitting is expected to result in more accurate directional fracture propagation, while minimising lateral micro fractures in the surrounding rock mass which is required to remain undamaged.

Jan 1, 1995

By D M. Menne

This paper is intended to give a general review of current gold extraction technology for free-milling or non-refractory auriferous ores. Fundamental process concepts and some of the differences between the current technologies is referred to. Typical flowsheets and layouts are provided and it is demonstrated that technology for extracting free-milling gold is relatively simple. For environmentally sensitive areas such as encountered in New Zealand relevant cyanide decay and destruction technology is also discussed. Brief mention is made of some likely future innovations. Finally reference is made of New Zealand's previous significant contribution to gold extraction technology. These contributions were pioneering ranging from the cyanide leaching of gold to adsorption by carbon and precipitation by zinc. New Zealand has not allowed its potential gold projects to develop at a rate commensurate with the rest of the world thereby stifling its renowned innovative approach in this technology. It is time for New Zealand mining to recognise its unique opportunities in developing gold extraction technology and again take a rightful place in leading the way.

Jan 1, 1986

From time to time efforts have been made to classify rocks according to their hardness, toughness and abrasiveness, and to use these classifications to provide an indication of the ease or difficulty with which they may be drilled. However, rocks classified as of similar type on this basis may vary considerably in their .resistance to the penetration of a rock drill bit due to differences in their physical state.For instance, fine grained rocks of granular texture are more difficult to drill than equivalent' rocks of coarser structure, altered rocks drill more readily than unaltered ones, and silicified rocks usually exceedingly hard and tough may be so shattered by movement as to be drilled at a rate comparable to quite soft rocks. Therefore, considerable latitude has existed in this method of defining their drillability, and no values generally acceptable have materiaJised; so that, when the drilling properties of rocks are discussed, it is common practice to refer to their hardness or toughness in a greater or lesser degree depending to some extent on the emotional state of the drill runner.REFERENCES AND STANDARDSThe 'introduction of tungsten-carbide tipped rock-drill bits for use with percussion rock-drills has thrown increasing emphasis on the need for defining a rock's resistance to penetration in a more concise and generally acceptable...

Jan 1, 1950

By M J. Kindley

The Golden Cross Gold Mine Project is now fully operational and into its second year of operation. Because of its location in the sensitive Coromandel Peninsula , strict water management and environmental requirements had to be met. This led to the development of new technologies for cyanide recovery and the adoption of advanced water management and water treatment systems. This paper discusses the water management and treatment system adopted for contaminated water at Golden Cross and provides data on the operational history to date.

Jan 1, 1993

The Indonesian province of Papua is a remote jungle-clad region covering the western half of the mountainous island of New Guinea. Despite being relatively under-explored to this day,Papua is home to the greatest mineral success story of the 20th century. The Grasberg/Ertsberg minerals district atop the central dividing range contains the worldÆs largest reserve of both copper and gold (Freeport-McMoRan Copper and Gold, 2002). With large mines at Ok Tedi,Por gera and Lihir,and many well-delineated resources such as Frieda River,Wafi and Hidden Valley, neighbouring Papua New Guinea,the eastern half of New Guinea has enjoyed sustained exploration campaigns for gold and copper since the mid 1960s. The combined Grasberg and PNG exploration successes can be measured in terms of ounces of gold produced over the last decade versus available landmass,conf irming the island of New Guinea and surrounding islands as a world-class destination for gold explorers. Yet despite this obvious regional prospectivity and the profitability of the Grasberg operation, a sustained exploration effort in the Papua province in Indonesia has not been achieved. Periodic political constraints, poor infrastructure, high costs, operational challenges, social and environmental concerns and lack of immediate exploration success often impact exploration investment decisions. Accordingly a lesser number of mineral occurrences have been documented in Papua compared to those seen along tectonic strike in geologically similar Papua New Guinea.

Jan 1, 2004

For tax purposes a mining company is a New Zealand company whose principal source of income is from the business of mining, or exploring for certain specified minerals in New Zealand. New Zealand tax law distinguishes between a non-resident mining operator and a mining company, with the only major difference in tax treatment being the corporate tax rates. New Zealand mining companies are taxed at 28 per cent, whereas non-resident mining operators are taxed at 33 per cent of taxable income. These provisions also apply to the petroleum mining industry. Individuals who carry on the business of mining are also specifically defined in the Act. They are termed as 'resident mining operators'. Non-resident mining operators are non-residents of New Zealand who carry on mining ventures as a business in New Zealand. Mining ventures are defined as the exploring, searching and mining of specified minerals, including development work carried out for profits. Similar provisions apply to the petroleum mining sector. Specified minerals are defined in the Income Tax Act 1976 ('the Act') and while no useful purpose is obtained by listing them in the paper, they include a larger number of industrial and commercial minerals. The Minister of Finance is also empowered to add to the list by publishing his determination in the Gazette.

Jan 1, 1988

By Holmes R. J, Miles J. G

An on-stream shale detector has been developed that is suitable for use on conveyor belts carrying iron ore of up to 200 mm particle size. The shale is distinguished from high-grade iron ore by means of the substantially greater total natural gamma-ray activity (400-3000 keV) of the shale, which is due to the presence of uranium (214Bi), thorium (208TI) and potassium (40K). Other gangue materials, sueh as highly siliceous cherts and jaspilites, escape detection because of their low activity. A dynamic trial of the shale detector at Mt Whaleback, using a large-volume (100 × 100 400 mm long) "Polyscin" Nal(TI) gamma-ray detector, demonstrated that as little as 20 tonne of ore on a conveyor belt (equivalent to partial truckloads of ore) can readily be monitored for shale content.

Jan 1, 1981

Some of the major factors affecting ore reserve estimation in gold mines are discussed together with their impact on computational methods.The major priority in ore reserve estimation is to get sampling and geological problems resolved. Poor basic information cannot be remedied by mathematical methods.Generally the more complex a deposit becomes the greater the need for subjective assessment and the less applicable are more complex ore reserve methodologies.

Jan 1, 1984

There is very little in Australian mining law that sets out the rights of mining tenement and exploration licence holders as against other parties who wish to carry out ground or aerial surveillance over those areas.There have already been several legal actions arising out of this lack, and more can be expected as the public places more rigorous constraints on corporate and individual behaviour. Field personnel, who are mainly fairly junior and less experienced, are entitled to some guidance from the minerals industry, guidance which up to now appears to have been either lacking or covering such a wide range of standards from corporation to corporation as to be virtually useless.Because each State writes its own laws there is no consistency, and the laws generally are lagging behind developments in the industry. In particular, the practice of granting mining tenements for sporadic exploration, a practice that is a leftover from much earlier mining law, has dotted the Australian continent with unattended and unmarked or poorly marked tenements that are difficult to find but confer on the holder prior rights to the minerals under them. Entry onto those areas in most jurisdictions is an offence and their existence compromises the efforts of regional explorers.This clearly unsatisfactory situation requires remedying, which is the purpose of these proposals. A more systematic approach to the granting of reconnaissance, regional and detailed exploration, mining, and retention rights will eliminate much of the problem. For the rest, a code of practice needs to be adopted as soon as possible.

Jan 1, 1996

The investment worth of a mineral deposit can only be realistically evaluated in relation to specific engineering design criteria, which fully details the proposed method of exploitation. These criteria have not in general been taken into serious consideration when leaseholders have reported reserves in the past. In fact, many "reserve" figures quoted are probably more correctly classified as geological resources. The industry now recognises that it is necessary to take into consideration not only grade and mill recovery factors, but also likely mining and processing costs as well as the current market price for the commodity. Once having estimated those costs which are applicable to the resource under study, they can be deducted from the gross inherent worth of the orebody to result in an estimate of the potential net revenue. Through a process of interactive trial mine designs and evaluation, reserves can be quantified to provide an estimate of the available recoverable economic reserves given a set of assumed cost and operational parameters. It follows then, that the available economic reserve recoverable from a given resource will vary from time-to-time as cost and price factors vary in response to changing technology and economic factors. A methodology is described which may be used to derive economic recoverable reserves based on a computerised model of the geological resource data and appropriate economic and operational cost algorithms. Examples are provided from both coal and gold studies to illustrate the impact of economic criteria on the magnitude of the reserve figure reported for each project.

Jan 1, 1987

Results from current NERDDC funded research into the geotechnology of highwall trench mining methods have clear implications for mine planners in the areas of blast design, trench shape, location of the surcharge spoil and remnant coal pillar design.Adoption of successful smooth wall blasting techniques not only removes safety hazards from the trench face, but limits development of bedding partings at the seam contacts that interrupt the smooth transition of stress across the coal seam.

Jan 1, 1992