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By F Jullian, L Jofre

Many maintenance managers find it difficult to justify investments in maintenance improvement initiatives. In part, this is due to a tendency by mine managers to regard maintenance purely as a cost centre, and not as a process able to influence productive capacity and profit. It is also hindered by a lack of alignment between commonly used maintenance performance measures and key business drivers, and the lack of formal business training amongst maintenance professionals. With this in mind, a model to assist maintenance managers in evaluating the benefits of maintenance improvement projects was recently formulated. The model considers four cost saving dimensions. These are: 1. reduction in the cost of unplanned repairs and maintenance,2. increased or accelerated production and/or sales,3. spares inventory reduction, and4. reduction in over-investment in physical assets and operating costs. This paper discusses the application of this model and a number of numerical examples are given to justify investments in maintenance improvement projects having varying objectives.

Jan 1, 2006

By Hedley TP

Success for underground coal mine operators in the 1990's and beyond will be dependent upon better understanding of the dynamics of their operating environment, and extension of emerging technologies to reach new levels of output and productivity. The Collieries Division of B.H.P. Steel International Group clearly identifies with the concept of business/product life cycles - and the need to adopt strategies that can drive the business successfully into the future. Three main thrusts within BHP Collieries Division relate to: 1) Detailed assessment of current mines to determine: a) The real output potential of the current facilities. b) What factors now inhibit the full potential from being realised. c) Opportunities that exist to enhance overall mine performance. 2) Based upon the findings of these studies, putting into place cost effective strategies and systems for the ongoing "tuning" of the mine. 3) of new/improved technology primarily in areas of: a) Coal cutting and underground coal clearance. b) Controlling the overall mine gas Regime.

Jan 1, 1987

By Quilliam B, Richmond G

Aberfoyle Ltd. has utilised a variety of flotation technologies in the Hellyer concentrator in North-Western Tasmania. Hellyer ore, with its slow flotation rates and low rate differentials between values and gangue, requires the use of long residence times and low air consumption rates in the flotation circuit. The operation of the flotation circuit, with a nominal residence time of 7 hours, has necessitated the development of a control system to provide continuity through operator shift changes. Cell selections at Hellyer varied from the 54 m3 hybrid Dorf Oliver / Maxwell (DO/MX) cells, to smaller 32 m3 Maxwell cells, conventional Don-Oliver 300 (8.5 m3) and 600 (17 m3) trough cells, and a column cell. The advantages of the large cells included low specific power consumptions and a low capital cost. However, problems with mixing and the maintenance of consistent froth depth have been identified in the hybrid DO/MX cells. Short circuiting in the trough cells was apparent, causing a considerable reduction in metallurgical performance. The column cell performs to expectation, although the application is not ideal.

Jan 1, 1991

By Jankowski P

The Bannockburn gold deposit is located 67 km north-west of Leonora in a poorly exposed part of the Norseman-Wiluna belt of Western Australia. The deposit consists of narrow, complexly shaped orebodies which have presented a challenge to find successful grade control and mining methods. The deposit also presents an opportunity to examine in detail the geology of this part of the Norseman-Wiluna belt.This paper discusses the geology and structure of the Bannockburn gold deposit as well as the grade control and mining systems developed to define the ore and extract it with minimum dilution. We discuss the different techniques employed for grade control in the past and their shortcomings, and the evolution of the present system of doing grade control in cross section from blast hole assays.

Jan 1, 1993

Ventilation challenges are often encountered when an underground mine expands to new zones and it often is the case to make a thorough review of the existing system and assess immediate and future airflow needs at the desired quantity and quality. An unexpected mine plan change that calls for increased development and production from new areas can impose a strain on the existing ventilation system. Budgetary constraints can also demand creativity in design on the mine ventilation engineerÆs part. Since the addition of several mining horizons it had become obvious at the Meikle mine that something had to be done to increase airflow quantity and quality in the old main zones because most of the ventilation resources had been channelled for development in the new mining horizons. An airflow assessment of the existing system had to be performed and it was determined that the airflow quantity had to be increased by at least 30 per cent and the quality of the air had to be improved by reducing nuisance and respirable dust and at the same time reducing the airflow temperature before it was used in a few mining zones. At the conclusion of the airflow assessment it was determined that a third centrifugal fan would be installed on a new 3.05 m diameter borehole from surface to underground. By a careful study of temperature conditions over time it was determined that an evaporative cooling spray chamber would be sufficient to cool the airflow down from the high dry bulb temperatures observed down to saturation at the wet bulb temperature. At the same time excessive nuisance dust generated as a result of the airflow travelling a long way in a haulage drift will be knocked down in the spray chamber resulting in cool, clean air in the mining districts. Expansion of the existing surface ammonia refrigeration plant was out of the question for several reasons. The fact that the airflow was hot and dry meant that evaporative cooling spray chambers could achieve lower working temperatures at a very low cost compared to the expansion of the chilled water plant. The expansion of the ventilation system at Meikle mine and the use of evaporative cooling spray chambers were demonstrated to be very successful and the information presented in this paper can be of benefit to other mines experiencing the same ventilation problems as was the case at the Meikle mine.

Jan 1, 2005

There is little doubt that the vision (Spectre) of Voisey's Bay has completely spooked the Northern Hemisphere view on nickel to the exclusion of considering any other future nickel project. Voisey's Bay orebody is of world-class and will influence world nickel and cobalt supply for a very long time - but - has the world yet started to consider the enormous cost of acquisition and development of this find or the nickel price it will need to attract to cover these costs and its operating costs and keep its bankers and shareholders happy. That price will be the critical factor in determining Voisey's effect on world nickel and will be critical in ranking other new projects aimed at making up the nickel short fall created by the on-going demand for austenitic stainless steel. In my view, there is little doubt that some if not most of these `other' new projects will be developed in the South West Pacific from lateritic Resources.

Jan 1, 1996

The optimum plant capacity for a new mine is usually based on empirical studies or ærules of thumbÆ, subject to confirmation by detailed scheduling of the proposed mining operation. The mining industry has a record of poor returns on investment and a high rate of project failure using these methods, with under-performance in grade being a common experience. The assumption that æeconomies of scaleÆ will result from increasing throughput rates needs to be balanced by an awareness of the adverse effects of increasing the rate beyond a level that issupportable by the resource. For each scale of operation considered, it is a reality that for any intended head grade, at the associated intended cut-off grade, the actual head grade achieved will fall as the mining rate increases. This effect is known to people at operations but is not recognised in current ore reserve estimation methodology. Once recognised, this dependency of head grade on mining rate can be quantified and used to establish the economically optimum mining and processing rate for a new project. A simple analysis is proposed, which may be extended to detailed spreadsheet modelling for financialoptimisation.

Jan 1, 2002

Various aspects of the history of mining at The Zinc Corporation, Limited (ZC) and New Broken Hill Consolidated Limited (NHHC) are examined. There are some discussions about the various methods used to mine the pillars left after the primary mining operations, with an enphasis being placed on the more modern pillar mining methods. Some new pillar mining proposals are presented. INTRODUCTION In the past, pillar reserves at ZC/NBHC have been scheduled for mining by labour intensive and high unit cost mining methods. These methods include both undercut and fill and overhand square set timber stoping. Recent technological advances in large diameter longhole drilling and high charge density explosives have culminated in the mechanised Vertical Crater Retreat (VCR) mining method and this method has been successfully used for the extraction of two pillars at NBHC and more stopes are planned. However the use of VCR methods for mining pillars at ZC/NBHC is restricted to approximately 50 per cent of the total pillar reserves and it appears that high cost methods will be needed to mine the remaining Pillars.

Jan 1, 1983

By Ritter K-C, Sturgul J. R, Filess T

The proposed Lihir open pit gold mine is located on Lihir Island in New Ireland Province, Papua New Guinea. The mine will be located within a volcanic caldera, part of which forms the adjacent Luise Harbour. Kennecott Corporation started engineering design work in 1988 and ended in 1993 when a Feasibility Report was submitted to the Papua New Guinea government by RTZ/Kennecott. The project will be managed by the Lihir Management Company. The mining operation will produce approximately 350 Mt of waste and 62 Mt of low-grade ore over the life of open pit mining. Landforms and traditional land use by Lihirians preclude storing mine waste and some of the low-grade ore on land close to the mine site. The mine waste will be composed of hard rock and soft soild like material which cannot be safely used to construct large land waste repositories by truck dumping. Submarine disposal by bottom discharging barges is the only safe disposal method. The barges will also be required to construct a waste platform along the shore for stockpiling low-grade ore. A simulation model of the waste handling system was written in GPSS/H¦ to assist engineers in selecting the optimum size and quantity of barges and loading docks by analysing the interaction between excavators, trucks and barges. The simulation model was written in enough details to model the various functions that will be encountered during mining. Input parameters allowed for variations in the size and number of trucks, shovels, barges and loading docks. Variations in loading, hauling, and dumping times were from user specified distributions. In order to visualise the interaction between the components of the waste mining operation, the simulation was animated using Proof AnimationT""'. It is believed that this is the first application of an animated simulation study for a mine still in the planning stages.

Jan 1, 1995

By G J. Wilkie, P A. Revell

The R&D landscape for ore pre-concentration technologies within mining is characterised by the development of individual technologies and point solutions. This presents METS and mining companies with the combined challenge of understanding how to apply pre-concentration technologies to create maximum value, and how to sustainably integrate the technologies into their businesses to maintain the value. The paper will consider the requirements of an integrated pre-concentration system and presents a portfolio of R&D projects that have co-developed and integrated a suite of new precencentration technologies and methodologies across the mining value chain. Focus areas include in-situ orebody characterisation, blast design, real time cross belt mineral sensing, and consideration of how much data needs to be acquired in order to make value based decisions between ore pre-concentration options. An ore pre-concentration workflow is presented to demonstrate how additional optimisation opportunities are enabled both by moving decision points further upstream in the value chain, and by integrating the concepts of pre-concentration into the design of mineral processing equipment. Additionally, several research projects examine the non-technical factors that present barriers to uptake of new technologies within mining companies. Organisational culture, risk management and socio-political factors are discussed and a set of management tools are presented that allow organisations to self-assess their readiness for new technology uptake, along with process models to assist management with identifying and navigating the ecosystem of stakeholders that are decision makers in the use of pre-concentration technologies.

Nov 10, 2020

My closest personal connection with the problems of rehabilitation comes from two years spent on a project at Weipa. At the beginning I am fairly certain that the engineers did not understand the mental processes of the ecologist they were dealing with. I am absolutely certain that the ecologist did not understand the minds of the engineers. This form of the two cultures problem is the root of some of the matters that lie behind this lecture. It is possible to establish a stabilising cover of vegetation on virtually any land surface, short of a cliff. While the biologist knows this he also knows that the physical and chemical nature of a given acre of land combines with climate to define quite sharply just what plants can be grown there. In the case of land after mining the range of plants may be quite limited. The engineer, and his masters in the accounting section, seem (in my experience) to expect that rehabilitation can be carried on with equal speed and facility in any location. This belief commonly leads to a situation where rehabilitation is not considered until mining is well under way. True, the mine must be proved as an assured profit- earner before money can be justified for the non-productive (to the miner) expense of rehabilitation. But when the miner finally starts rehabilitation he does not always get a convincing and speedy result. Furthermore, the failure may not be easy to overcome. This is even more likely to be the sequence of events if the miner wants, or is obliged, to specify the exact type of vegetation to be produced, e. g. commercial forest, pasture,' or the original native vegetation.

Jan 1, 1971

By M Scamardella

The CSA Mine is located at Cobar, New South Wales, where it was in continuous operation from 1966 to the time it went into receivership on 29 January 1998. When it closed it was under the ownership of Golden Shamrock. Glencore International, in conjunction with Mt Lyell Mining, undertook a due diligence study to determine the feasibility to re-open the mine. This envisaged operating CSA Mine as a low-cost, copper concentrate producer under the direction of Cobar Management Pty Ltd (CMPL). The new workforce would consist of contractor trades people in operating functions under the co-ordination of CMPL staff, both on the surface and underground. This was the key to establishing the new culture in the workforce. The orebodies at CSA Mine are steeply dipping with copper-lead-zinc mineralisation in zones of strong alterations in a fine-grained siltstone host sequence. The predominant economic minerals are chalcopyrite, sphalerite and galena. The major gauge minerals are pyrrhotite, pyrite, chlorite, sericite and quartz. Ore for the project is being developed and mined from two high grade copper lenses within the QTS North system. Chalcopyrite occurs in two forms. The first consists of coarse chalcopyrite grains in association with pyrrhotite or pyrite. The second form consists of chalcopyrite grains intergrown with pyrrhotite grains. This form of chalcopyrite is quite rare. It allows electrochemical interactions between grains, resulting in rapid oxidation of the chalcopyrite surface. Physically this ore looks like, and has been mistaken for æpeacock oreÆ, ie bornite, but is infact oxidised chalcopyrite.

Jan 1, 2000

While the new Minister of Economic Development sends his apologies at being unable to speak at this Conference, I am delighted to present on his behalf. The Ministry of Economic Development is not only responsible for managing the Crown mineral estate, but also for developing initiatives and policies to promote regional economic development and for managing the GovernmentÆs broader economic development strategy. IÆd like to talk to you today about the critical links that need to exist between these three areas.   I am going to start with a question for all of you. What do these towns have in common? +        Waiuku, +        Thames, +        New Plymouth, +        Nelson, +        Greymouth, +        Arrowtown, +        Reefton, +        Palmerston, and +        Dunedin.   The answer is minerals. These towns were nearly all founded on the back of minerals and mining. In the case of Greymouth it was gold that brought the people to the mouth of the Grey River and it is coal that sustains the town.   In 1870 the town of Shortland had 20 000 people, 90 hotels and was twice the size of Auckland. We now know Shortland as Thames, and of course Auckland is considerably larger. One wonders whether the good folk of Shortland suffered from ætraffic jamsÆ with 90 pubs to navigate between. Gold mining in the Aorere River near Collingwood led early entrepreneurs to develop the land surrounding Nelson as a food basket to sustain the mining population. Nelson is still thriving on this legacy today. The town of Palmerston was founded in 1862 as a stopping point for gold miners heading into central Otago. The gold rush made Dunedin New ZealandÆs first highly industrialised city. Reefton on the West Coast was the first town in New Zealand to have electric lights and in the recent past we were wondering whoÆd be left to turn them off. New Plymouth, and Waiuku are still known as energy and mining centres.   By contrast once thriving towns like Capleston, Canvastown and Blackball are just names on a map now, and at the extreme you have places like Waiuta which has been reclaimed by the West Coast forest. Queenstown was built off the back of the gold rush, but by 1900 with the gold gone, only 190 people lived there yet Queenstown has managed to rebuild itself thanks to some other stunning natural assets. These examples help illustrate three key points that I am sure will each be extensively linked with our minerals and mining industries. First, NZÆs development and that of its regions has been, and continues to be, inextricably linked with our minerals and mining industries.   Second, things change. Sectors, regions and countries must continually adapt and improve if the are to avoid the fate of the Waiutas of this world. And third, the development challenges faced by NZ and its mining industry in the 21st century are vastly more complex than in the past. Governments and industry alike must balance and respond to a range of domestic and international environmental, cultural, economic and other interests and considerations. If you thought of your industry as æjust digging holes in the groundÆ then you may as well simply stick your head in one!

Jan 1, 2005

The use of systematic review methods, derived from System Safety approaches used in the North American nuclear power industry, have become an accepted approach for seeking "approval" for new coal mining equipment and operational changes in NSW. Based on risk analysis, they provide a valuable and needed framework for the reduction of losses related to people, equipment and production.

Jan 1, 1991

By King D, Dickinson S. B, Matheson R. S

Graham Hall and V. M. Cottle (Rosebery, Tas.) : In their paper on "The Mineralized Rift Valleys of Tasmania", Campana, Dickinson, King and Matheson have summarized a wealth of data from many sources. In proposing the new concept of a rift valley structure, they claim to have found a new guide to regional ore control and distribution in North-west Tasmania.Although the authors acknowledge suggestions made by us prior to publication of the pa:per, we are still at variance with their conclusions. We are not convinced that a rift valley structure exist~d when the Ordovician conglomerate was deposited. We are unable to find evidence for Cambrian deposition in a rift valley or reason to project the structure to embrace Hercules, Rosebery, and "possibly" Mt Bischoff.That the Great Lyell Fault (the authors' Owen Rift Fault) is a promising place to look for ore is not a new idea, but the existence of important ore deposits away from the structure reveals its inability to provide an adequate explanation of regional mineral distribution. A well-known structure that does have an influence on ore deposition is not discussed by the authors.STRUCTURAL CONSIDERATIONSThe great thickness of coarse unsorted Ordovician conglomerate lying in an elongate but narrow belt of country is presented as evidence of its deposition centrally within a rift valley, the position-of which is now said to be outlined by resistant slabs of the conglomerate. The marginal shears of the rift are said to show up well along the edges of the conglomerate.

Jan 1, 1959

By Tsuchida N

The history of world nickel production has been affected significantly by the supply and demand situation and fluctuation of LME price of nickel metal. In the beginning of the 1980s, the decline of price and demand lead to the withdrawal of un-competitive producers and the shrinkage of the production capacity. During the same period, Sumitomo Metal Mining maintained the production level with continuous improvement of the traditional matte electrorefining process. However, Sumitomo has recognised that the continuous improvement alone does not promise us the ability to catch up with rapid changes in the world. In the meantime, Sumitomo intensively researched chloride hydrometallurgy and has developed the chloride process for the nickel refining. This includes the solvent extraction and chloride electrowinning in the mixed sulphide process and the chlorine leach of the anode slime arising from matte electrorefining. In the late-1980s, Sumitomo Metal Mining decided to develop a new nickel refining technology based on chloride hydrometallurgy. The new process was designed from the comprehensive aspects involving safety and the environment. Construction of the plant for the matte chlorine leach electrowinning (MCLE) process was commenced in 1991. The MCLE plant with a capacity to 2000 tonnes per month has been commissioned at Niihama since 1992. The process has provided high productivity, overall good economics and high quality of electrolytic nickel produced. After the establishment of the process, Sumitomo has maintained continuous improvement of the new process and has attained the best practice of the work classification.

Jan 1, 1996

By Morrison R. D, Davis J. J, Fraser B, Kojovic T

1991 saw the completion of a three-year $1.1 million research and development program in mineral sands beneficiation, funded in two associated projects by the Australian mineral sands industry through AMIRA, and carried out by the Julius Kruttschnitt Mineral Research Centre. It is believed to be the largest R&D project in mineral sands ever conducted by a university research group. It covered dry plant operation, and delivered several products to the industrial sponsors, including: ò A detailed characterisation of the radiation properties, mineralogy and size distribution of inhaleable dust arising in dry plants. ò New process models of magnetic and electrostatic separators. ò New on-line instruments for elemental assay (in association with AMDEL) and bulk conductivity measurements of dry process streams. ò Demonstration and evaluation of the Magstream magnetohydrostatic separation technology.

Jan 1, 1992

Coal has been mined in New South Wales for nearly 200 years and prior to 1970 the vast majority of this coal was mined from underground mines using bord and pillar or similar systems.Since 1970 there have been two notable changes in coal production trends in New South Wales as can be seen from Figure 1.1. The steady growth in coal mined by open cut methods. Open cut output grew from about seven per cent of the State's output in 1970/71 to 43 per cent in 1990/91.2. The steady growth in coal mined by the longwall method. longwall output grew from negligible amounts in 1970/71 to 48 per cent of underground production in 1990/91. mines operating longwall units produced 61 per cent of underground production in 1990/91.

Jan 1, 1992

By O S. Maluleke

In some deposits valuable heavy mineral quality is poor due to increased mineral surface coatings from higher slimes and more competent sand orebodies. Mineral surface coating can include silica or aluminium rich clay minerals and iron based minerals that render the final product quality off-specification, in this case specifically ilmenite and zircon. Conventional physical beneficiation processes such as magnetic separation, electrostatic separation and gravity separation are not able to remove these surface coatings. Surface dependent separation techniques such as electrostatic separators are affected by these coatings which hinders the rejection of non-valuable mineral from product. Attrition scrubbing is the most commonly used technique to reduce surface coatings, using mechanically induced particle to particle interaction, abrasion and shearing.In many cases it is a challenge to measure the surface removal efficiency of these scrubbing units. Elemental analysis techniques (ie X-ray flourescence) (XRF) in a multi mineral environment are unable to measure surface impurity reduction with enough precision. Mineralogical analysis (in this case Qemscan®) has constraints in terms of sample preparation with highly coated particles being plucked out during block polishing. This paper suggests a combination of laboratory separation techniques coupled with elemental analysis to evaluate the surface removal efficiency. Three different types of feed materials were used to analyse the efficiency of surface removal using production attritioner scrubbers. This approach relates the downstream beneficiation plant’s expected performance with that of the attrition scrubber’s scrubbing efficiency.

Oct 5, 2011

A new two-metre column self-heating test procedure has been developed at the University of Queensland, which clearly shows the hot spot development phases that take place in bulk coal self-heating. The column results provide a more reliable indication of the self-heating propensity of coal than small-scale index tests. At the same time, off-gas evolution patterns associated with hot spot development are obtained, including the recognition of hydrogen evolution from oxidation at temperatures less than 80¦C. Subtle differences in off-gas evolution from self-heating between gassy and gas-drained coal are also apparent. This new approach to coal self-heating assessment offers an opportunity to further the understanding of the complexities of spontaneous combustion and will enable more accurate risk assessment for the coal industry.

Jan 1, 2005