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By A Litwinowicz, M Laxman, A Fourie, A L. Li

This paper presents a design approach and analytical methods that were used for assessing the potential of static liquefaction and developing the mitigation measures for a tailings dams. The rigour of the design and analysis approach represented leading practise in the industry to address static liquefaction, which contributed to a robust design with high confidence and certainty. The salient features of our approach to static liquefaction included geotechnical investigation and tailings characterisation, static liquefaction screening assessment, static liquefaction triggering analysis, limit equilibrium analyses and numerical modelling of static liquefaction using the NorSand model, which was amongst the first tailings dam projects involving numerical modelling of static liquefaction using these methods.

Jul 1, 2021

Most mining operations have been happy to live in blissful ignorance of what their equipment is really capable of. Shareholders have been shown increasing tonnes output per employee (due to rationalising employee numbers). It is now known that the best practice for large mining trucks is 52 per cent higher than average or best practice for excavators is 41 per cent higher than average, or 38 per cent in shovels or 35 per cent with draglines, etc. The data is available. The bell curve of performance is flat. Substantial underperformance is rife. If you are working in or supplying equipment or services to one of the majority of operating mines that donÆt achieve best practice surely you want to know why. Or maybe you donÆt? For many mining people this sort of knowledge could be dangerous to their career so keeping the MD or CEO in the dark is a good option. Many suppliers donÆt want the performance of their equipment benchmarked? Mining consultants donÆt have the data so they are happy to keep guessing. Unfortunately, many Business Improvement or Business Excellence projects are about ticking the participantÆs æcareer boxesÆ. The first step to capacity utilisation is knowing what the capacity is. Even then people and culture will get in the way. People are the biggest hurdle to capacity utilisation. This paper will discuss what the mine of the future (and today) will need to do to utilise the productive capacity of its assets. It is not just benchmarking. It is not just automation. It is not just technology. It is about engaging those people who impact on equipment performance; right from the operator up to the Mine Manager. Doing it better involves a process to facilitate change and a culture which says it is OK to try even if you are wrong.

Jan 1, 2009

The suitability of char from Yallourn brown coal as a filler for carbon electrodes used in the aluminium smelting industry has been assessed on the basis of the specifications usually laid down by electrode manufacturers for petroleum coke fillers. The purity specifications can be met by a simple acid leaching of the coal before carbonization. The true density of char produced at 1200°C is within 5 per cent of the specification figure, but the bulk density of char obtained from as-mined coal is only half that specified for petroleum coke.Although this can be increased to three-quarters of the specified figure by briquetting the coal before carbonization, further increases would be very difficult to achieve, as the remaining shortfall in density is due to an extensive microporosity developed in the particles of char during carbonization.

Jan 1, 1970

With the exhaustion of orebodies close to the main haulage shaft of the Emperor mine, an increased rate of development, aimed at earlier investigation of values disclosed by exploration drill holes has been attained with an overall reduction in unit costs.This paper describes the techniques used in rates of advance up to and exceeding 1,000 ft per 28-day period.

Jan 1, 1966

A broker relies heavily on mineral valuations and independent experts' reports to provide the fundamental information, both technical and commercial, which provides the basis of estimating the sharemarket value of securities and underlying assets. It is important to appreciate the significant variance that can occur between the market value and other types of valuation at a particular point in time. In general, most experts' reports and valuations seek to provide estimates of technical/fundamental or ""fair"" value which correspond to the Corporations Law and accounting standards requirements. They do not usually attempt to estimate (stock) market values and it is usually and quite correctly the broker's task to estimate market values on the basis of a technical appraisal and consideration of all other commercial, market and financial influences. Therefore ideally, an independent experts' report or information memorandum will include material relating to commercial and management aspects of a company as well as detailed technical reviews and fundamental valuations. Wherever sensible cash flow projections can be made, cash flow-derived valuations, usually based on discounted cash flow (DCF) calculations, remain the preferred valuation methodology. Brokers in general would not argue with this preference. However, there is a paucity of examples of valuations where alternative methods are applied as a check on the reasonableness of a DCF-based estimate.

Jan 1, 1994

By G P. Taylor

Mining Lease SML 57 was registered to Mount Kasi on 5 January, 1995. The Mount Kasi gold mine is located in Vanua Levu, Fiji's second largest island and operated from 1932 to 1946 producing 261,000t of ore at an average grade of 7.5g/t Au. The deposit represents a structurally controlled style of high sulphidation copper gold mineralisation with peripheral low sulphidation mesothermal vein type gold mineralisation. The resource consists of 1,048,000 tonnes of residual soils (eluvium) containing 1.9 g/t Au at 0.5 g/t Au cut off and 1,240,000 tonnes of hard rock at 3.0 g/t Au and 1.0 g/t Au cut. 94 drill holes, 298 auger holes and 85 pits were modelled to outline the resource. 29% of the pits bottomed in mineralisation and it is likely the full thickness of eluvium has been understated. The pit is scheduled to produce 500,000 tonnes of ore per annum to yield 35,000 ounces of gold with an initial 2 years of eluvial ore followed by a further 2 years of hard rock ore. Total capital costs are estimated to be less than 10.0 million dollars with construction planned to commence in 1995. The likelihood of locating further ore is high.

Jan 1, 1995

By R Bezuidenhout, J K. Claflin, S R. La Brooy, G M. Wardell-Johnson, A M. Claflin

Best practice gold (Au) recovery is not an accident. It is the result of proper operation of the adsorption circuit using good quality activated carbon. A conventional carbon ‘regeneration’ kiln cannot process carbon fouled with floatation chemicals and achieve best practice gold recovery. A high temperature, controlled atmosphere carbon ‘reactivation’ kiln is required. Carbon circuit design allows for low quality carbon by increasing the carbon advance rate, carbon inventory and setting an easily achieved and commercially prudent solution tails target of typically 0.02 ppm Au. These design criteria are important to ensure the commercial success of the gold operation in the first instance. Most carbon ‘regeneration’ kilns will produce carbon of sufficient quality to achieve a 0.02 ppm Au solution tail in the absence of flotation reagents.Best practice recovery is considered less than 0.005 ppm Au in solution reporting to tails. If the carbon is heavily fouled, as it will be if used for flotation leach circuits, then a conventional carbon ‘regeneration’ kiln cannot achieve world’s best practice recovery no matter how much carbon is advanced. World’s best practice gold recovery requires a carbon ‘reactivation’ kiln and the whole of the carbon circuit operated optimally.The competing reactions occurring in a carbon ‘reactivation’ kiln are presented and discussed in terms of kiln design and operation. New industrial and laboratory findings are presented to fill gaps in the body of knowledge and identify that a large reduction in residence time at temperature will not significantly impair reactivation, but can significantly reduce the size and cost of the kiln or permit significantly increased carbon throughput.The carbon circuit performance is modelled in terms of gold adsorption, as a function of carbon reactivation using ‘simulation of carbon-in-leach/carbon-in-pulp circuits’ (SIMCIL). An optimum carbon advance rate is identified as a function of optimum carbon ‘reactivation’ kiln operation to achieve 0.005 ppm Au in the tails solution. A conventional carbon ‘regeneration’ kiln is compared to a state-of-the-art carbon ‘reactivation’ kiln in terms of reactivation performance and gold recovery.CITATION:Claflin, J K, La Brooy, S R, Wardell-Johnson, G M, Bezuidenhout, R and Claflin, A M, 2017. Optimising carbon reactivation kiln operation, in Proceedings MetPlant 2017, pp 346–364 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

By J Ward, B Rohrlach, B Rosero, J Silva, O Poma

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Alpala copper-gold deposit is a recent, high-grade porphyry Cu-Au discovery located in the Imbabura Province of north-western Ecuador. The deposit lies along the crustal-scale Chimbo-Toachi Fault Zone within the Dagua-Piñon terrane, which is an oceanic plateau accreted to the South American convergent margin in the Late Cretaceous. The deposit is hosted by quartz diorite stocks that intrude andesitic volcanic breccias of the Oligocene to mid-Miocene San Juan de Lachas Formation. Miocene-age calc-alkaline plutonism is associated with porphyry Cu, Cu-Mo and Cu-Au deposits in southern and northern Ecuador. The Alpala deposit lies along a sector of the Miocene arc that has recently been underplated by the Carnegie Ridge seamount chain that induced shoaling of the subducted Nazca plate beneath northern Ecuador.Surface expressions of the deposit were recognised in May 2012 during follow-up of stream sediment anomalies, when outcropping sheeted and stockwork porphyry-related veins were discovered in Quebrada Alpala. The roots of a NW-trending, structurally-controlled lithocap were recognised over an area of 4.5 × 0.9 km. The remnant lithocap exhibits well-defined mineral zonation mapped by TerraSpecTM analyses on grid soil samples. Soil sampling, heliborne magnetic surveying and channel sampling defined initial drill targets.Seven diamond drill holes were completed in the year from September 2013. Drill hole CSD-13-005 intersected 672 m grading 0.93 per cent Cu and 0.91 g/t Au in high-temperature, inner propylitic and locally potassic-altered quartz diorite intrusions. Overlying hydrothermal clay alteration assemblages define the base of the lithocap. A NW–SE trending footwall structure defines the south-west margin of the deposit. Drill hole 5 intersected high-grade sheeted ‘B-type’ and ‘C-type’ veins (Gustafson and Hunt, 1975) that lie along the south-west margin of an 1100 × 500 m magnetic anomaly that is the focus of ongoing exploration.CITATION:Rohrlach, B, Poma, O, Rosero, B, Silva, J and Ward, J, 2015. High-grade porphyry copper-gold mineralisation in north-west Ecuador – The Alpala Cu-Au porphyry discovery , in Proceedings PACRIM 2015 Congress, pp 369–376 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

The areas of concern lay in the processing of, and the subsequent hearing into, Waihi Gold's resource consent applications to extend Martha Mine. The proposed amendments to the Resource Management Act 1991 might see the introduction of contestability in the processing of applications - which would have assisted Waihi Gold; and the use of commissioners to hear the applications, with a right of appeal to the Environment Court on points of law only. It is also proposed to have major applications heard directly by the Environment Court. If Waihi Gold's applications had been heard at first instance by the Court, the delays in time and associated costs would have been reduced. However a hearing by commissioners only would not have been satisfactory, there being no right of appeal against the conditions of consent, which if implemented as granted by the Councils would have had a significant impact on the costs associated with the extended project.

Jan 1, 1998

In March 2003, Rio Tinto Coal AustraliaÆs (RTCA) new Hail Creek open cut coal mine commenced operations in the Bowen Basin. Hail Creek is a two-seam strip mining operation utilising two 90 m3 draglines and a fleet of excavators and trucks to remove the overburden. All overburden at Hail Creek is blasted prior to excavation. The mine conducts its own drill and blast operations while engaging Dyno Nobel for the provision of explosives supply and loading truck (bulk explosives vehicle û BEV) services. This arrangement was favoured over outsourcing the entire blasting function to a contractor. Subsequent to a value engineering review, the mine set about developing and implementing a blasting operation that did not rely on the need to store bulk quantities of ammonium nitrate on site. There were advantages identified in doing this, in particular the reduction of capital expenditure required and reduced exposure to a number of recently introduced security requirements. This approach also makes sense operationally. The establishment of reload facilities for the BEV close to the blasting location, where turnaround times are kept to a minimum, increases the productivity of the BEV. For this strategy to be successful the logistics of ammonium nitrate supply into the blasting operations has to be well planned and thoroughly executed. This means a robust planning and forecasting arrangement needs to be established with the supplier and transporters of the ammonium nitrate. To date, 80 million bcm of overburden has been blasted at Hail Creek and each year the quantity of overburden requiring blasting is increasing. The purpose of this paper is to present the findings of a study: evaluating the effectiveness to date of the strategy to conduct blasting operations without ammonium nitrate storage on site, and identifying whether there is a limit to which this strategy can operate after which the introduction of bulk ammonium nitrate storage facilities are necessary.

Jan 1, 2007

By D E. Gadd

Since October 1972, New Zealand Steel Mining Ltd has loaded around ten million tonnes of ironsand concentrate from single-point mooring buoys located off-shore at Taharoa on the west coast of the North Island of New Zealand. Before the first off-shore loading system was installed a considerable research effort was applied to proving the slurry loading technique. Subsequently the system has been expanded and a new buoy, pipelines and pumping system were installed in early 1978. Since then 110 000 DWT class ore carriers have been loaded at rates of around 2600 tonnes per hour through twin submarine pipelines. This paper reviews the operation of the ship loading system and attempts to answer the question: 'If the Taharoa operation were to be planned in 1980, would the same research spending be necessary or have published research results since, made such practical tests unnecessary?'

Jan 1, 1980

By A E. Petts

Record iron ore prices and a renaissance of infrastructure in the Pilbara have Flinders Mines poised to move from explorer/developer to an iron ore producer. The potential of the company’s Pilbara Iron Ore Project was first highlighted by the announcement of Rio Tinto’s Caliwingina North deposit to the north and the Fortescue Metals group’s Serenity deposit in the southeast. The success of Flinders Mines’ exploration has been based on incorporating landscape studies into an existing geological framework, and using this to understand the iron-rich materials that were emplaced during the Tertiary. The development of the Delta and Eagle deposit resource models highlights this process. There are three main mineralisation styles at the project; detrital iron, channel iron and bedded iron deposits. They have textural and mineralogical similarities with comparative deposits in the region. Gaining an insight into the geological processes unique to detrital iron deposits and more distal channel iron deposits has been important to understanding the geometallurgy of the mineralisation. The model sits comfortably with other regional oregenesis models and allows a contextual framework to be developed around the timing of deposition of the Fe-rich detritus and pisolitic nodules that dominate the deposits. The exploration model also allows Flinders to explore more effectively for bedded iron mineralisation developed prior to, and since the development of the Tertiary weathering landscape.

Jul 11, 2011

By A Giblett, K Afewu

This paper uses a case study to demonstrate best practices techniques for predicting the contribution of gravity concentration in a gold recovery process flowsheet. The case study was selected as an example of an ore with a marginal gravity gold content, which makes the value of a gravity circuit difficult to quantify. In this instance the value of leveraging a significant knowledgebase of operating gravity circuit performance to support the decision making process was demonstrated. This case study analysis serves as a useful demonstration of best practice methodologies supporting decisions to include or exclude gravity recovery in a gold recovery process flowsheet.CITATION:Giblett, A and Afewu, K, 2015. Do we need a gravity circuit or not? A case study in applying best practice, in Proceedings MetPlant 2015, pp 288–295 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

Ensuring the success of a major resource development project, whether in the Gippsland Basin or elsewhere, is typically both a complex and costly process. It is therefore imperative from the point of view of the proponents of such a project - and in particular the financiers - that everything possible be done to minimise administrative confusion and delay in the establishment phase of the project, and to put systems in place which enable the project to run smoothly and efficiently in the later stages of its development and operation. An essential element in this process is ensuring that the project management is able to come to terms with and deal effectively with the relevant planning and environmental laws.

Jan 1, 1992

Distribution of Settling Velocity of Irregular Particles and its Effect on Jig Separation Efficiency

Sep 13, 2010

By N Boughen

This paper synthesises the findings of five studies undertaken by the CSIRO Wealth from Oceans Flagship in 2009-10. This research explores the concerns, expectations, and information needs of a range of stakeholders, (ie government, seafloor exploration and mining industry, other marine industries, environmental non-government organisations (NGOs), community members) in relation to the possible exploration and mining of minerals and aggregates from the seafloor, as well as the conditions for meaningful engagement with communities regarding seafloor exploration and mining (SEM) activities. The SEM industry has been described as the ‘next minerals frontier’, as incentives to explore and mine seafloor resources increase because of diminishing reserves of easily accessible onshore mineral and aggregate deposits. However, the conditions (if any) under which SEM would be acceptable to stakeholders (notably the public and regulators) have not been established. This work seeks to address this gap and ascertain the levels at which potential environmental and social impacts become unacceptable to those stakeholders. The research follows an earlier phase of studies undertaken in 2006 - 2008 that: identified the opportunities and barriers to the development of SEM in Australia, took the first step towards understanding the public and political contexts surrounding the industry, and mapped the positions of key stakeholders and captured their major issues and concerns. Together, these two phases of research confirm that environmental concerns dominate stakeholders’ responses to the idea of an expanded industry. However, the most recent phase of research has also found that, similar to current onshore scenarios, reservations due to environmental concerns do not completely outweigh social and economic objectives. This is provided stakeholders feel confident that there are systems in place (regulatory frameworks, watchdogs, independent research, and stakeholder consultation) to ensure that all interests are protected. When making decisions about the social acceptability of potential seafloor mining, stakeholders favour a precautionary approach, supported by rigorous scientific analysis of the potential environmental impacts, transparent and socially responsive management processes, and meaningful stakeholder engagement. This paper outlines the details of these findings, which may also be relevant to understanding the social acceptability or ‘social licence to operate’ for other future mining scenarios featuring a new approach or technology.

Nov 22, 2011

Small scale' table concentration tests have many critics. Many metallurgists consider that such tests are of problematical value because of the difficulties involved in conducting and interpreting them.Many kinds of small-scale ore dressing tests are difficult to conduct, and there is, perhaps, good reason for thinking that table concentration tests are amongst the most difficuIt.Interpretation of results from small-scale tests is the responsibility of the metallurgists and engineers in charge, and it is often held that small-scale table concentration tests are particularly difficmlt to interpret.TESTING FOR TABLE CONCENTRATIONOn analysis it appears that the difficulties encountered in conducting small-scale table concentration tests are of three fairly distinct kinds. Firstly, there are difficulties due inherently to the smallscale nature of the operations; for example the smaller width of all mineral bands on the table and the less complete separation due to the shorter length of travel between the feed and discharge points.Secondly, there are the effects of batch operation owing to the fact that the mineral particles behave differently during the initial period when the sample is just beginning to spread over the table, the middle period when feed and discharge are even and continuous, and the final stage, when the last of the sample has been added and the table is beginning to empty itself.

Jan 1, 1954

The past decade has seen revolutionary advances in communications and information-handling techniques which have been stimulated by "cold war" military requirements and by current programmes for probing into outer space. The tools used in exploration for petroleum and minerals have been improved significantly as a result of this new space age technology and even greater improvements are on the way.Two areas of technical activity have been particularly fruitful in enhancing the effectiveness of exploration methods. These are1. the development of new approaches, based on information theory,for extracting signal from noise more efficiently than before, and2. the use of high-speed digital computers for storing and processing all kinds of exploration information, not only geophysical but geological as well.In seismic prospecting, use of information theory has led to new techniques such as time-domain filtering, wave-number filtering and correlation methods which have made it possible to obtain usable reflection data from areas which were previously considered non reflective. Complex playback and other data processing facilities have been developed to apply these approaches.Digitization of geophysical data for handling by high-speed electronic computers facilitates many of these techniques for signal-to-noise improvement. Direct digital recording of seismic data in the field is now being d'one on an experimental basis in the United States, and this should become a standard procedure, at least for problem areas.The increased dynamic range, flexibility of filtering and other data processing, and convenience of information storage and retrieval make digital recording attractive in spite of its high cost compared to conventional analogue methods. Digital computers are being programmed to carry out many operations in data reduction and interpretation with substantial savings in time and cost over conventional procedures.INTROPUCTIONIn the years that have passed since the end of the Second World War, the western world has witnessed a technological revolution which may be as far reaching in its ultimate impqct as the Industrial Revolution of the last century.

Jan 1, 1963

By T P. Fischer, S N. Williams, N C. Sturchio

Chemical and isotopic analyses of fumarole gases from Galeras Volcano, Colombia provide significant insights into the origin of volatile components in the magma. Water comprises a mixture of magmatic (rock-equilibrated at high temperature) and meteoric, with the relative proportions varying through time. Carbon isotopes are most consistent with a mantle source, although other contributions to the system cannot be ruled out. Nitrogen most likely originated from organic matter in subducted oceanic sediments. All of these 'primary' components have been modified somewhat by interaction or exchange with other reservoirs during ascent to the surface. In addition to information on the origin of the gases, these data show significant temporal variations precursory to eruptive events. Chemical ratios change and water becomes more meteoric in character prior to eruptions.

Jan 1, 1995

Treatment of the Siirt-Madenk÷y Ores by Flotation

Sep 13, 2010