Search Documents

Principles of management in ore preparation before process of enrichment of chrysotile ores are discussed. The formulas, which were tested in industrial conditions, are offered, which may be used for averaging of chrysotile-asbestos fibres by content in ore and grade.

Dec 6, 2010

As far as is known at the present time, important ore occurrences at Mount Isa are restricted to the Urquhart Shale. These occur at Mount Isa itself, and some 13 miles north along strike at the Northern Leases.The primary silver-lead-zinc and copper orebodies occur as adjacent but discretc entities in lithologieally distinct host rocks. The copper orebodies occur in an envelope of "Silica Dolomite", whereas the silver-lead zinc orebodies occur in shale typical of the Urquhart Shale in general.At both Mount Isa and the Northern Leases, secondary lead orebodies occur at thc surface representing primary stratiform silver-lead-zinc sulphide accumulations in the fresh rocks at depth.Secondary copper orebodies are known only at Mount Isa, where they have formed in favourable environments, but unlike the secondary lead orebodies, not in the positions of the former primary mineralization that gave rise to them. The secondary copper is localized in shale remote from the point where the copper was released into solution by weathering. It was derived from very low grade fracture fillings and disseminations of chalcopyrite in the outcropping or suboutcropping crest of the "Silica Dolomite".Primary silver-lead-zinc orebodies arc oxidized without significant transport or secondary enrichment, but secondary copper orebodies arc characterized by considerable transport and extreme secondary enrichment.The original water table stood at approximately 1,150 ft (mine datum) and for the majority of the mine area controlled the base of complete oxidation fairly closely.An oxidized zone approximately 175 ft deep is general in the Urquhart Shale.Structures affecting ground conditions have influenced oxidation and leaching of the silver-lcad-zinc orebodies, and have had effects vital to the formation of secondary copper orebodies.

Jan 1, 1966

By S Saydam

Professional engineers need to be able to apply university learning to practice. In particular, they have to take responsibility for interactions between technical systems and the complex social environments in which they operate. The most effective way of building this competency is through active experiential learning. We have been developing an advanced educational integrated simulation system to provide mining engineering students with an interactive and immersive learning experience that is not otherwise possible. This will give students an authentic experience in working with industry software packages, while also contextualising the learning in terms of the broader and longer-term impact of technical decisions. We have been piloting the system, in undergraduate courses in order to establish its effectiveness in building systems thinking competencies for mining engineering. For postgraduate students and professionals, the same tools and methods can support studies of more challenging and complex scenarios where mining engineers have to place their decisions within complex global industry contexts.

Nov 22, 2011

By K Sanematsu

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Ore deposits of rare earth elements (REE) in South-East Asia are classified into four types: carbonatite, allanite, ion-adsorption and placer. Occurrences of the carbonatite deposits are confined almost exclusively to the Red River Fault Zone of northern Vietnam. Since the carbonatites contain dominantly REE fluorocarbonates (eg bastnasite) and lesser amounts of monazite, they are rich in light REE but poor in heavy REE. The ion-adsorption type deposits and prospects were found in Myanmar, Vietnam and Thailand. The ion-adsorption ores generally show lower REE grades than those of the carbonatite type and placer deposits; however, they could be enriched in HREE, which are more precious and scarce commodities than LREE. The ores consist of weathered granites with a significant amount of ion-exchangeable REE, which are extracted by using a dilute electrolyte solution. The ion-exchangeable REE are likely to be sourced from REE fluorocarbonates, allanite and titanite because these minerals are relatively susceptible to weathering and release REE3+ ions into soil water. In contrast, monazite and xenotime are resistant to chemical weathering and could form placer ores. Placer monazite and xenotime have been processed as by-products of placer Sn, Zr or Ti in Malaysia, Thailand and Indonesia, although the current production is small.CITATION:Sanematsu, K, 2015. Rare earth element deposits and prospective areas in South-East Asia, in Proceedings PACRIM 2015 Congress, pp 671–678 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By G D. Matthews, M E. Haylett, S Khosrowshahi, A Weeks

Effective domaining is fundamental to geostatistical modelling for grade control. Through analysis of lithological, structural and alteration logging data, effective groupings (domains) can be identified and employed for estimation or simulation purposes.The poor definition of domains can adversely affect the grade control model resulting in a misinterpretation of the optimal ore-waste boundary and ultimately reduces the quality of recovered ore. The implementation of an appropriate domaining strategy is therefore expected to improve recovery and reconciliation.A thorough understanding of the geology of the deposit and adequate sample data is required for selecting domains. For new deposits, a resource drill database and resource model may be the only information available. Where extension to a previous operation is taking place, historic grade control, mapping and exposed geology may be used to improve domain selection. Preconceptions about domains, should they exist, need to be re-evaluated and tested to ensure they are fit for the purposes of grade control.While mining progresses, the domain model is re-evaluated to ensure that the previous interpretation is still suitable for the present configuration and geology. The grade control process, being iterative, lends itself to regular review and continuous improvement as further data is collected during the grade control cycle. Regular updates to the geology model, mapping, geostatistical data analysis and review of variography will provide indications of a changing domaining environment.Narrow vein gold deposits, which may have several factors influencing mineralisation, present considerable domaining challenges. By scrutinising the data, sample populations can be grouped into domains, which not only improve ore recovery, but help assist in the development of a mine geology model.CITATION:Matthews, G D, Haylett, M E, Weeks, A and Khosrowshahi, S, 2014. Effective domain selection for grade control in narrow vein gold deposits, in Proceedings Ninth International Mining Geology Conference 2014 , pp 191–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By R Dunne, G Lane, S Ha, D Dreisinger

The paper outlines the 17 Mt/a Telfer Project plant process design from sample selection to feasibility study design. The 366 Mt Telfer mine reserve consists of a diverse range of copper and gold mineralisation, from massive sulfide reef ores to stockwork ore, oxide copper minerals to chalcopyrite, siltstone to competent quartzite, all with relatively high levels of gravity recoverable gold. The complexity of the orebody demanded a flexible plant that could recover copper and gold values by a combination of gravity recovery, flotation and concentrate leaching. The demands of treating ore from a high grade underground mine and a variable grade open pit (that includes underground old mine workings) necessitated a dual train approach from primary crushing to concentrate production in order to minimise the requirement for campaigning of different ore types. An extensive sampling, testwork and technical evaluation program was undertaken to identify processing characteristics and the optimum process route for each ore type. The design experience included: the development of robust primary stockpiling and pebble crushing concepts; detailed review of scale-up of SAG and ball mill pilot plant data to plant scale; the selection of two 15 MW SAG mills and two 13 MW ball mills for the grinding circuit; and detailed modelling of the pyrite concentrate carbon-in-leach (CIL)/sulfidisation acidification recovery thickening (SART)/acidification volatilisation recovery (AVR) process to optimise design for copper and cyanide recovery from leach liquors. The Telfer plant design also measures the development of process design based on experiences at the Cadia Hill Cu/Au concentrator, commissioned in 1998. The differences between the two plants are compared and contrasted.

Jan 1, 2003

By A M. Suchowerska, J P. Carter, J P. Hambleton

"In order to effectively predict the roof collapse of underground openings using continuum models, it is imperative that a realistic failure criterion is used to represent the rock mass. However, for coal mining operations, there is still uncertainty as to the appropriate failure criterion that should be used for the coal measure strata. This study compares stability numbers and collapse mechanisms for a rectangular underground opening predicted based on three commonly used failure criteria: the standard Mohr-Coulomb, Mohr-Coulomb with a tension cut-off and Hoek-Brown. Three methods of analysis are considered: an analytical upper bound method an upper and lower bound finite element formulation the displacement finite element method.The theoretical results are also compared with field measurements of subsidence above longwall coal mining. For the standard Mohr-Coulomb failure criterion, the friction angle governs the shape of the collapse mechanism, and the so-called critical width (the cavity width above which failures extend to the ground surface) ascertained from field observations in the New South Wales coalfields corresponds to a friction angle of approximately 30°. On the other hand, predictions obtained based on the Hoek-Brown failure criterion consistently overestimate the critical width. The results also show that tensile failure governs the stability of the cavity and shape of the collapse mechanism when a tension cut-off is introduced for the Mohr-Coulomb yield criterion.CITATION:Suchowerska, A M, Hambleton, J P and Carter, J P, 2014. Prediction of roof collapse for rectangular underground openings, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference, pp 367–374 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 5, 2014

By A Brzovic, E Córdova

In an underground mine, different mining activities such as undercutting and cave progression generate redistribution in the present in situ stress field, and these changes are represented in the rock mass through induced seismicity.In order to study and analyse the induced seismicity generated in El Teniente, a block model was developed to account for the dissipated seismic energy through different areas of the mine from 1992 to 2015. More than 2.1 million seismic events were unified and classified in 3D in order to be used for the interpolations. The resultant model variables account for the accumulated energy releases in a monthly time resolution, and provide the ability to intersect different 3D entities with the stored information in the blocks, and estimate the energy evolution inside these entities.The generated model was used to analyse the geotechnical variables that determine the seismic response for the rock mass in the mine, such as geometry and direction of advance of the undercut fronts, lithological domains, and to study the ‘work’ the rock mass needed to go through in order to generate caving in areas with different stress settings.A specific area of the mine under high-stress conditions was analysed by studying the seismic energy associated with two subsidence caves interacting around the project, the modelled lithology. Using the same approach two adjacent projects are analysed to understand the released energy from the rock mass based on different stress and geotechnical settings for each project.CITATION:Córdova, E, Brzovic, A and González, R, 2016. Analysis of progressive seismicity and its correlation with geotechnical variables at the El Teniente Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 835–844 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By P Toor

Mill filling is an important operational parameter in a SAG mill circuit and by its control and optimisation it can produce significant improvements in production capacity and energy efficiency. However, it is industry practice to report mill load as the total output given by load cells, or kPa for systems based on lubrication bearing back pressure, rather than the actual percent total mill filling.Ball trajectory is another critical parameter as overthrow can result in accelerated liner wear and possibly liner failure whilst underthrow can result in reduced grinding action. The assessment of ball trajectory cannot be done in isolation as the toe of the charge needs to be determined to make any meaningful assessment. Thus both total percent mill filling and mill trajectory are critical parameters; however neither is reported or available to metallurgy or processing teams in real time or a regular basis.In this study the performance of a fixed speed SAG mill was assessed and optimised by employing mill trajectory models and using the JKMRC power model to calculate percent total mill filling. Power Curves, which correlate ball filling, mill filling and mill power, were also developed. The Power Curves, with additional knowledge from the trajectory models allowed for the identification of optimal operating regions for the mill.CITATION:Toor, P, 2015. Optimisation of a semi-autogenous grinding mill through trajectory and power modelling, in Proceedings MetPlant 2015, pp 142–149 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

The history of soft and hard rock underground mining is blemished with regional instabilities of mine workings. Whilst the potential consequences of regional instability events are recognised to be high, there is a false perception that the probability of them occurring is very low. In fact, Australia has averaged more than one event per year for the past 20 years. At least five fatalities and over $100 million of losses have been associated with the events. As such, they are a core risk to underground mining and have a significant effect on the quadruple bottom line of business û safety, environment, community acceptance and economics. This paper explores the important roles that risk management has in reducing the probability and consequences of regional instabilities. It concludes that education and continuing professional development are essential elements for effectively managing the risk.

Jan 1, 2003

By R Razanatsimba, A Galli

A mining company has entered into contractual commitments to supply certain quantities of its product to clients in each time period. Failure to fulfil its obligations would damage its reputation as a reliable supplier. The planned production would normally be sufficient unless major problems such as highwall failures, roof falls, natural disaster, or strikes that interrupt production or delays in obtaining environmental permits, occur. To overcome these difficulties, the company may be able to obtain more of the commodity: from its strategic stockpile (if there is sufficient there); by buying it on the spot market; or for some commodities such as gold and uranium, by leasing it. Two sources of uncertainty, the spot price of the commodity and the occurrence of serious incidents that interrupt production, are considered. For simplicity it is assumed that the commodity price follows a geometric Brownian motion, that productions incidents have a binomial distribution, that they are independent from one time period to another and that they do not affect prices. A branching tree structure is used to model the joint evolution of prices and production incidents. The aim of this research project was to evaluate the companyÆs options for fulfilling its contractual commitments. When evaluating these options, multi-stage stochastic programming with recourse was used to solve this problem because in addition to providing the dollar value of the project, it gives decision-makers the æroadmapÆ to reach the optimal value. That is, how much material should be bought/sold on the spot market, how much to add to/subtract from the stockpile, how much to lease and in the worst case what the shortfall would be, for each time period as a function of the current spot price and breakdown status. A case-study over a five-year period is used to illustrate the proposed procedure. In this study the production would be sufficient to cover the companyÆs contractual commitments unless production incidents occur. Focus is on evaluating the impact of the quantity initially in the stockpile on the value of the project when the commodity market is tight, that is, when only small quantities can be bought on the spot market or by leasing.

Sep 26, 2011

By J L. Maule, S J. Mathews, K A. Rodgers

Gold and Silver bearing epithermal veins of the Golden Cross deposit are hosted in Miocene and Pliocene calc-alkaline volcanics occurring 8 km northwest of Waihi at the southern extent of the Coromandel Peninsula, North Island, New Zealand. Veining occurred during a period of hydrothermal activity that began early to late Pliocene, and possibly continued into the Pleistocene.   Field relations and petrographic relationships reveal that multiple generations of FeS2 occur in the Golden Cross region, with FeS2 occurring in all nine rock types recognised at Golden Cross. The variability of FeS2 morphology was investigated by preparation of high purity FeS2 separates, and grain counting. Marcasite is the dominant FeS2 phase at Golden Cross, and along with pyrite is shown to have a systematic habit variation. Pyrite shows a sequence from cubes through octahedra to pyritohedra to dendritic growth. This pyrite sequence conforms to an experimentally determined sequence. The parallel sequence for marcasite at Golden Cross is from tabular through bladed aggregates to euhedral miscellaneous marcasite morphologies. The FeS2 sequences observed are believed to be due to increasing temperature, and perhaps also increasing FeS2-oversaturation and fluid flow.

Jan 1, 1994

By Lewis PJ, Halfpenny R, Craighead GA

Exploration drilling by Joint Venture partners CRA Exploration Pty Ltd and Elders Mining PNG Pty Ltd has discovered a signif- icant copper and gold deposit at the Wafi River prospect, 60km WSW of Lae in Papua New Guinea. An indicated resource of 18Mt at 2.5g/t Au using a lg/t cutoff has been delineated in Zone A. No estimate has been determined for the separate copper occurr- ence at Rafferty's Zone but the copper will be significant to the project. Metallurgical studies on the gold indicate that the primary ore is refractory to direct cyanidation giving a highly variable and inadequate response. All conventional refractory ore oxidation techniques perform well on both ore and pyrite concentrate and oxidation occurs rapidly. No metallurgical studies on the copper mineralisation have been undertaken. Hypogene covellite and chalcocite copper mineralisation is associated with an intensely quartz-stockworked, and quartz and alunite-altered intrusive. Economically significant gold mineralisation occurs in distal subhorizontal lenses, within a sedimentary host, that plunge toward the intrusive. These lenses are sandwiched between overlying quartz and alunite-altered zones and underlying quartz and smectite zones in a mixed zone of quartz, dickite, kaolinite and illite alteration. The alteration and mineralisation is classified as a high sulphidation, epithermal style resulting from the influx of hot, acid magmatic fluids. Preliminary land ownership, road access, power supply and mine infrastructure studies are in progress. The project is currently at an advanced exploration stage.

Jan 1, 1991

The whole of the iron ore required by the Broken Hill Proprietary Company Limited at the Newcastle Steel Works, and Australian Iron and Steel Limited, at Hoskins' Kembla Works, is drawn from the Iron Knob, Iron Monarch, Iron Prince and Iron Baron deposits situated in the northern part of Eyre's Peninsula, South Australia.The Iron Knob and Iron Monarch deposits are near the township of Iron Knob, approximately 42 miles W.S.W. of Port Augusta, whilst the Iron Prince and Iron Baron deposits are some 18 miles due south from Iron Knob, in another group of leases, the adjacent township being known as Iron Baron.The ore mined at Iron Knob, Iron Monarch, Iron Prince and Iron Baron is conveyed on the Company's 3ft. 6-in. gauge tramway to Whyalla, on the western side of Spencer's Gulf, approximately 45 miles south by west of Port Augusta whence it is shipped to Newcastle and Port Kembla.SHORT HISTORY.The establishment in South Australia of the lead smelting industry at Port Pirie, Dry Creek and Port Adelaide in the...

Jan 1, 1937

By N van Aarde, B A. Moore, S van der Merwe

Frequently materials handling operations are compromised by transfer chute problems ranging from high wear rates, blockages and ineffective loading of the downstream conveyor. This paper will present the design flow implemented to overcome problems in two case studies utilising discrete element modelling incorporating material characterisation.Material testing is relevant in achieving a valid discrete element method (DEM) simulation model and subsequently a valuable design tool for transfer chute assessment and design. It is well recognised that in the current growth and demand for mineral resources, leading to ever increasing conveyor capacities associated with export terminals and mineral processing facilities that transfer chutes are a key focus point. The successful performance of the transfer chute is also dependent on operating with a ærobust rangeÆ of material flowability and handling characteristics. This requirement is crucial in accommodating mineral ores from developing resources, which are often more friable and stickier than in past decades.This paper will include details of chute installations associated with iron ore and coking coal, from the DEM simulations through to the performance of the installed and commissioned plant.CITATION:Moore, B A, van der Merwe, S and van Aarde, N, 2013. Implementation of advanced transfer chute designs, in Proceedings Iron Ore 2013 , pp 445-450 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By T Wettainen, G Shekhar, M Stromsten, B Skawina

The aim of a transportation system in an underground mine is to move the rock masses from one location to another in the most preferable manner by minimising the long and short-term operational costs. A continuous improvement of material transportation systems used in mines generates a need for continuous investigation of the current and new underground transportation systems. In an underground mine, an orepass is a common system used to transfer the material to the lower levels. If this system loses the ability to transport or store the necessary material capacities, it would result in production disturbances. In this paper, discrete event simulation (DES) was utilised to analyse the material inflow and outflow of the orepass systems when subjected to the different conditions. The study presented in this paper is based on the Malmberget mine, the second largest underground sublevel caving (SLC) iron ore operation in the world.

Mar 15, 2021

Exploration and mining title administration in the Northern Territory has changed dramatically over the last 20 years. These changes have occurred due to legislative amendments, technological developments, and the changing face of the mining industry. The first legislation to control mining in the Northern Territory was the Northern Territory Gold Mining Act (1873) of South Australia. In 1911, control of the Northern Territory was passed from South Australia to the Commonwealth. As a result of the mining boom which followed the discovery of gold in Tennant Creek in 1932, the Commonwealth passed the Mining Ordinance of 1939. This legislation was amended 39 times and stayed in force until July 1982, when the self-governing Northern Territory passed the Mining Act 1980. This Act is still in force and is continuously under review. The first computerised mining titles system, REGIS, was created in 1984/85 and was, to all intents and purposes, just a computerised index. Various modifications ensued, and in 1989 the Titles Database was unveiled. The database has developed to be one of the most sophisticated yet user-friendly mining titles databases in Australia. In excess of 50 companies have access to the database from their own offices. Work continues on its development and fine-tuning. The paper outlines the development of the database since inception.

Jan 1, 1994

By J, T C. McCuaig, J Hodgkison, T Fouet

Olympic Dam is the eighth largest Cu deposit and the largest U deposit in the world, with approximately 35 million tonnes of contained Cu and 1.2 million tonnes of U. The most recent resource estimate was for 2.95 billion tonnes of mineralised material with average grades of 1.2 per cent Cu, 0.4 kg/t U, 0.5 g/t Au, 2.6 g/t Ag as contained mineral resources. Olympic Dam is expected to produce >200 000 tonnes of Cu and 4200 tonnes of U3O8 from 9.8 million tonnes of ore in 2004, making it the 12th largest Cu producer in the world. One of the impediments to achieving targeted rates of production has been oversize material (>0.9 m) reporting to stope draw points. A major contributor to oversize material may be overbreak along pre-existing structural weaknesses from stope walls and backs during the production life of a stope. Underbreaking to structures can also have a detrimental effect on the performance of a stope. In an effort to understand the influence of structural geology on stope performance, WMC Resources and SRK Consulting partnered during 2003 to refine the current system of structural mapping, and to use historical data to produce a structural interpretation covering a large part of the mining area. The interpretation has been wireframed in DATAMINETM into a three-dimensional structural framework model. To date, there are more than 600 structures of >50 m strike length incorporated into the structural framework model, which covers a study area 1500 m + 600 m + 350 m. A back-analysis exercise to assess the influence of interpreted structures on overbreak and underbreak was completed for laser-surveyed stopes.

Jan 1, 2004

By T Baumgartl, R I. Maczkowiack, O White, P D. Erskine

Queensland legislation, industry codes and policies relating to mine rehabilitation and closure create the expectation of successful progressive rehabilitation and that the post-mining environment is being returned to a condition suited to a pre-agreed, beneficial end use. Yet none of the rehabilitated mined land in the Bowen Basin has been certified as successful by authorities suggesting there is a gap between current rehabilitation and the full environmental outcomes that the legislation could deliver. We tested the veracity of this perspective and reflect on where responsibility for any discrepancy lies.We first reviewed current Queensland legislation and industry codes relating to stakeholder engagement, rehabilitation, closure planning and post-mining land use. We tested the accessibility of the documentation trail for several recent coal-mining projects in the Bowen Basin and examined the level of detail in approval documentation. We then assessed the rehabilitation performance reports of these mines in relation to the contents of their approval documents. Legislation, guidelines and codes repeatedly emphasise the need to plan for closure before mine operations begin and to progressively perform rehabilitation with an agreed end-use in mind. Early stakeholder involvement in these processes and transparency of actions and outcomes are also encouraged by government publications. Overall, in terms of transparency, we found that relevant documents are generally available to the persistent enquirer. However, the rehabilitation and closure undertakings given in both mine company and regulator documentation were commonly generic and rehabilitation obligations were not explicitly incorporated into rehabilitation plans. Rehabilitation reporting was also weak in that no distinction is required between successful and unsuccessful revegetation, nor to closure objectives and mine completion criteria. Responsibility for the apparent disconnect between regulatory intent and actual performance appears to begin with the regulator too readily allowing generic information and in not requiring performance reporting to correspond with approved post-mine conditions. As a result, companies may have a much greater rehabilitation and closure risk than mine management expects. More poignantly, the checks and balances that are in the legislation are not yielding the environmental outcomes of which they are capable.CITATION:White, O, Maczkowiack, R I, Erskine, P D and Baumgartl, T, 2012. Walk or talk - Is the current mine approval process in Queensland delivering rehabilitation and closure success?, in Proceedings Life-of-Mine 2012 , pp 59-68 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By R F. G Phelps, C J. S Sangster, G S. C

Narrow vein metalliferous mining in the UK has a long history, but there are only two small gold operations at present (Clogau and Gwynfynydd). Four further gold properties are at various stages of evaluation (Calliachar, Cononish, Curraghinalt and Maestryfer). The South Crofty tin mine closed earlier in the year. Narrow veins are exploited underground and are challenging to evaluate because of their geologically variable nature. They are generally less than 3 m wide, discordant, of variable dip (

Jan 1, 1998