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The comparison of belt drives with other types of power transmission involves the consideration of many factors before a final choice is made. Where other forms of power transmission might also be suitable, the selection of the correct type of belt has first to be made, in order to obtain a true comparison. The paper first deals with the types of belting available, followed by a description of most other forms of transmission equipment. An example is then given of the selection of suitable belts, which are then compared with other types of transmission. Comparative costs are also given. Reference charts provided show drives found suitable in general practice...

Jan 1, 1964

A review is presented of techniques cur- rently in use, or being developed, to enable the determination of virgin rock stress at consid- erable depth (> 1000 m) from small diameter sur- face drill holes (

Jan 1, 1975

By D Ziaja, W Jaspers

A brief history of the development of pneumatic flotation cells from early in the 20th century to the present day and a comparison to conventional cells demonstrates the efficiency and simplicity of design and operation of the ænew generationÆ of pneumatic cells. Recent successful testwork on phosphate minerals in the USA and a variety of coal types in Australia confirm the utility and efficiency of the design. The key aspects of this technology are improved recovery and selectivity with lower capital expenditure and operating costs.

Jan 1, 2005

By M S. N Hadi, J Hossein

Numerical modelling is extensively used in civil and mining engineering applications because of cost and risk problems associated with different experimental studies. In this study, the effect of resin thickness was evaluated in bolt-grout-concrete interaction and bending behaviour of a fully grouted bolt installed across joints in post failure region. Tests were conducted in 20 and 40 MPa concretes, and modelling simulations were made, using ANSYS version 8.1, to include both with and without different pretension loads. It was found that in all resin thickness, both the strength of the concrete and bolt pretension had major influences on the shear resistance and shear displacement of the reinforced medium. Also it was found that the strength of the surrounding concrete is more important than that of the grout thickness in both the shear resistance and shear displacement when the bolt is pretensioned.

Jan 1, 2005

Gold occurs at Mt. Charlotte associated with a stockwork of pyritised quartz veins in Unit 8 of the Golden Mile Dolerite. The ore- body is massive, 200m long and 40m wide and has been proved to over 600m below surface. Mining is by sublevel ring drill stoping with the ore recovered by diesel powered equipment. Ore reserves are based on traverses of diamond drill holes oriented to produce an equal intersection width on the two principal sets of quartz veins. Assay and geological boundaries are marked on each drill section and this boundary is transferred to mine plans and cross sections. Ring-drilling patterns are based on the cross sections and the resulting mining outline is transferred back to the drilling sections. The mine ore reserve is calculated from the mining outline.

Jan 1, 1979

The copper deposits at Pernatty Lagoon are predominately djurleite-digenite bodies beneath the permanent water table, and chrysocolla-atacamite-malachite above the permanent water table. The minerals havebeen deposited as sheets, lobes, and pods in zones suggestive of permeability channels or permeability basius with respect to groundwater circulation.Pyrite is deposited in the form of framboids, which reflects its biogenic origin. Copper-iron sulphides deposit by replacement of pre-existent pyrite, and rarely by direct deposition. The latter mode of formation results in complex crustification bandings of chalcopyrite, bornite, sulphur rich bornites, digenite, and blue remaining covellites. The copper-iron sulphides appear to reequilibrate under constrained oxidation, resulting in an iron depletion and associated copper enrichment, the final product of which is a djurleite-digenite assemblage and associated with goethite. Where copper mineralization/ host rock relationships have rendered the rocks entirely impermeable to post ore groundwater movement, then the copper-iron sulphides are preserved as the ore assemblages.Minor and trace minerals observed include sphalerite, carrollite, galena, wittichenite, and possibly tetrahedrite in the primary ores. In the oxidized ores cllprite, tenorite, and trace brochantite have been found.

Jan 1, 1976

Rock formation at shallow depths is generally associated with complex geology consisting of many joints, fractures, bedding planes, etc. Fragmentation results from primary blasts in such strata are therefore significantly influenced by structural discontinuities. To evaluate the role of discontinuities, which is of great use in the design of blasts in such conditions, a two-stage investigation program was taken up. In the first stage, model scale tests were conducted with single and double holes with the strike of discontinuities parallel and perpendicular to the face. Later, field studies were conducted in a limestone mine and a coal mine. Blast patterns were modified based on the results obtained from model scale blasts. Secondary blasting was taken as a measure to assess blast performance in the field, whereas mean fragment size, fine and coarse fragmentation indices were considered as fragmentation measures in model scale tests. Model tests indicated confinement of explosive energy by the discontinuities surrounding blasthole. Crater shape and size were significantly influenced by the orientation of joints with respect to the face. Modified blast designs with decreased burden x spacing patterns resulted in improved fragmentation in the field. A reduction of about 12 per cent in explosive consumption was recorded with modified blast designs. Boulder formation was observed to decrease by about 79 per cent as well.

Jan 1, 1995

By Agrawal A, Joshi A

Mochia mine, in culmination of depillaring operations, fired India's largest underground pillar blast consuming 145 tonnes of explosive and yielding 0.55 million tonnes of ore in June 1994. To protect main mine structures (situated at a distance of 250 to 350 m from the blast site) from resultant ground vibrations, the charge per delay was restricted to 2300 kg. The post-blast observations revealed that no damage was caused to these structures. However, the damage assessment survey of the mine workings situated in close proximity revealed a general trend in consonance with the distance from the blast and found to be well correlated with peak particle velocity.

Jan 1, 1995

By K Biegaj

During the author’s 25+ year career in mine management in various parts of the world (mostly in Australia), the author has been privileged to live and work in mining towns (not FIFO) for more than 20 years. And has personally observed other people from the mining industry carrying out work at home in an unsafe manner, eg pushing lawn mowers whilst wearing thongs or performing electrical jobs whilst standing on aluminium ladders, as well as many others. It is common that injuries sustained at home whilst on break are not reported upon arrival back on a mine site. A large number of compensation claims for injuries at work, which in fact had been sustained at home, come at substantial extra costs to mining companies.

May 5, 2022

By Liu Y

Ventilation, air leakage, and various cutting, loading and support movement operations all have a role in dust distribution on longwall faces as shown by the results of a large number of dust measurements on different longwall operations in the Bulli seam on the South Coast. It is concluded that leakage of air on the face has demonstrable mfluence on the exposure of the shearer operator to dust level. It is possible to calculate dust generated by various elements of a rrurung operation on the face from a single point measurement. In the examination of dust deposition from the source of generation as a function of particle size, it is found that respirable dust can remain airborne over long distances without any significant drop in concentration, if unobstructed.

Jan 1, 1995

Because of the work of the pioneers of sampling theory, we know the principles, test work and equations to use to design sampling systems to meet targets for precision and accuracy. However, we do not see such æproperÆ systems deployed everywhere a sample is obtained around mineral processing plants. In many cases, we do not have solutions that satisfy all of the theoretical, economic and practical considerations. There are some well-known problems, such as high-volume streams with wide size distributions combined with a sparse valuable component that is heterogeneously distributed (such as gold ore SAG mill feeds). However, other difficult sampling issues are common, such as streams which vary widely over a day in flow rate and slurry density (many flotation concentrates), and loaded CIP carbon on transfer to elution. Inventory measurement issues abound, especially for leaching operations where daily inventory change is significant for metallurgical accounting. The result is that operators realise that although they issue reports daily, they do not know what is actually going on in their plant on a daily basis with sufficient confidence to quickly diagnose problems or confidently predict the benefits of potential enhancements. The industry needs practical and economic solutions that can be awarded the ætheoretically correct samplerÆ tick in order to better understand and optimise their processes.

Jan 1, 2008

Australian contract mining as it is known today had its origins in the early-1980s. Before this time there were numerous examples of underground mine development, and specifically shaft sinking being carried out by contractors. However, these were typically international contracting companies who came to Australia for specific projects. Growth in the underground mining industry in the 1980s opened up the opportunity for contractors. Mine owners had a need for contractors who could bring technical and operational capabilities to a project combined with capital in the form of equipment. In the early years the contracting industry was dominated by smaller players who focussed on mine development. The relationship between mine owner and contractor was loose and typically contract documents were rarely referred to. Through the 1980s and 1990s the underground contracting industry in Australia grew to where today there are over 20 underground contracting companies operating in an industry with an estimated annual value in excess of $1 billion. Of these 20 companies approximately five dominate with annual turnovers exceeding $100 million. Underground contractors now provide all facets of underground mining including development and production. Over the last 20 years the underground contracting industry has been able to consistently lower costs to mine owners through a combination of:equipment productivity, labour productivity, and technical innovation.

Jan 1, 2002

This paper considers the standard of ore reserve assessments required by lenders when presented to support requests for project based loans. The way lenders use this information to structure a suitable financial package shows why ore reserves should be measured by industry set standards. This in turn raises questions concerning the assumptions used to derive mineable reserves from geological reserves. Consideration of the variety of related problems highlights the need for assessments to be defined according to acceptable standards. These should also address the suitability of the methodology to the assumed configuration of the orebody; the degree of variance and relaibility of estimates of grade and tonnage presented; and the estimation of probability that ore will in practice fall within the defined limits. In an increasingly international marketplace it is appropriate to compare Australian industry requirements to those of similar overseas industries, in this case the United States. Lenders would like to see that individuals responsible for the preparation of ore reserve estimates are certified on the basis of their skill and expereince by an industry body such as The AusIMM. The paper discusses how each of the parameters indicated above may impact upon a lender's assessment of the viability of a project. A number of practical examples are presented where inaccuracies or inadequacies in ore reserve information have led to reduced project performance.

Jan 1, 1987

Zinc produced by pyrometallurgical processing techniques suffers the disadvantage of restricted market potential because of its impurity contents, typically lead and cadmium. Market zinc to the Special High Grade (SHG) standard can only be produced by reflux distillation refining, which is costly in terms of energy and equipment, and potentially capacity limiting. Recent published laboratory work suggested that molten salt electrorefining of zinc metal is a potentially much cheaper alternative to the reflux distillation refining. The extrapolation of the laboratory results to an industrial configuration, however, resulted in an estimated power consumption for electrorefining and associated costs offering no advantage over current reflux distillation practice. A review of this estimate now shows that a serious error in calculation was made, and that the energy consumption for the electrorefining of molten zinc would be an order of magnitude lower than that for reflux distillation refining. While this is a promising indication, further research is required before development towards an industrial scale operation is warranted. This would particularly relate to the extent to which adverse electrolyte deterioration may take place and its potential effect on the anode and cathode efficiencies of the process. This paper considers the laboratory investigations required to explore the industrial potential of the molten salt electrorefining of zinc and foreshadows some of the practical problems to be solved in further development.

Jan 1, 2000

While there is reasonable agreement on the basic chemistry of the slag fuming process, there has been an on-going debate for nearly 50 years as to the nature of the rate controlling factors in its industrial application. There have been advocates in the technical literature for thermodynamic limitations on the one hand or kinetic limitations on the other. The different viewpoints result in very different predictions as to the technical and commercial potential of the process. A resolution of the debate becomes of importance as pyrometallurgical processes are advocated as a means of extracting environmentally deleterious elements from metallurgical wastes. The present paper reviews the arguments in favour of both equilibrium and kinetic control and puts forward the view that much of the evidence for limitation of the process by kinetic factors under all conditions is unconvincing. It is maintained that the process can approach thermodynamic equilibrium under industrial conditions and that this determines the ultimate limitation on its technical performance. It is acknowledged, however, that kinetic considerations may cause the batch process to fall well short of performance predicted on thermodynamic grounds. The strong process limitation arising from the influence of chemical thermodynamics on the likely outcome of a hypothetical continuous fuming process is contrasted with optimistic forecasts resulting from the extrapolation of process models based only on kinetic considerations.

Jan 1, 2000

Sulphide Corporation Pty. Limited operates a Lead/Zinc Smelter at Cockle Creek, some 11 miles from Newcastle, N. S. W . Works effluents totalling some 8, 500, 000 gallons/day join Cockle Creek some 1. 8 miles from its mouth in the most northerly section of Lake Macquarie, The Creek is also the source of the Works cooling water intake of which approximates 8, 000, 000 g.p. d. In view of the wide use of the Lake for recreational activities by the people of Newcastle and the surrounding areas, particular care must be taken to ensure that the control of effluent quality is of a high order. This paper outlines the philosophy and measures taken for the treatment and control of plant effluents discharging into Cockle Creek.

Jan 1, 1971

By K H. Esbensen

The critical role of representative sampling is featured and illustrated by selected examples from the geosciences and beyond. As there already are many demonstrations of the potential (and potentially large) economic consequences of ignoring proper standards with respect to representativity, eg for mining and minerals processing companies, which æstand to lose millions of dollars by failing to optimise exploitation of their mineral resourcesÆ, such need no further iteration here.This keynote lecture, rather, takes a point of departure from the opposite perspective: what is to be gained by a scrupulous stand for representativity? Honesty, reputation, credibility, market advantage - is what!CITATION:Esbensen, K H, 2012. The critical role of representative sampling, in Proceedings Sampling 2012 , pp 9-12 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

Computerisation of mine planning activities, specifically in the areas of geology, design and surveying, has been in progress for a number of years in underground metalliferous mines. The combined capabilities of hardware and software have only recently reached the levels necessary to fully support integrated mine planning computer systems in a graphical three dimensional environment. Despite the apparent capabilities of systems now on the market, many sites retain significant parts of their older paper based systems, and employ a mix of two or more software packages. This paper examines what underground metalliferous sites are doing in this area in Australia, and discusses the factors which are inhibiting full implementation of fully integrated computerised systems. Future directions for further developments in the field are also briefly discussed.

Jan 1, 1995

Outsourcing of mining operations and services is done for various reasons and there is no single model which fits all situations. Experienced contractors and mine owners have also developed, more often than not, jointly, numerous commercial arrangements and project delivery methods to suit their particular project. It is often the case that some mine owners who have not considered outsourcing to contractors do so because of a simple lack of understanding of the potential benefits. This paper will highlight the potential benefits and perceived disadvantages of outsourcing for mine owners and demonstrate how these issues have been addressed by the mining contracting community over recent times as well as demonstrate the evolution of current commercial arrangements in engaging mining contractors.

Jan 1, 2006

By A J. Moore

The Australian Coal Association Research Program (ACARP) funded project, No C14057, entitled æEffect of Blasting on InfrastructureÆ, has been carried out with the objectives of providing methodologies for the assessment of the strength of infrastructure types and the establishment of responsible and realistic limits. Personnel from Melbourne, Newcastle and Swinburne Universities and Terrock Consulting Engineers conducted the project. Infrastructure types including: conveyors; power transmission towers; wooden power poles; electrical substations; pipelines, bridges; public access roads and underground workings have been investigated by both field studies and structural analysis. Railways, underground telecom cables, dams and industrial buildings have been reviewed using general structural analysis. This paper has been prepared for the mining industry to provide a progress report on the project.

Jan 1, 2007