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Rational decision making is generally perceived by managers of operations to be a delicate process of committing large sums of money and putting other people's life at risk. Consequently most managers may argue that the decision process requires good judgement, intuition and extreme caution; and not one easily made through the use of fancy mathematical algorithms and computer programs. The advent of artificial intelligence and expert systems in the computer industry combined with recent technological innovations in mathematical and economic problem solving is sure to change this perception. PARETO OPTIMALITY is an economic and a mathematical optimisation concept applied to solving real life operational problems; and one that the current volatile economic forces would require managers to employ because it is virtually real. REALISMM is a computer software package developed using the principles of Pareto optimality, dynamic programming, optimal clustering of information and decision maker interaction to generate decision maker preferred solutions. REALISMM has scope for artificial intelligence and expert systems application for cases where the decision maker is unsure about his objective preferences.

Jan 1, 1993

It is shown that factors associated with conditions whIch are thermodynamically favourable for the formation of CuS04 in roasting lead to high copper recoveries on leaching. One of these factors is the ratio of the air to solids used for roasting. This can be varied widely without loss of temperature control in the sulphating roasting of many Australian copper concentrates.Thus, the prediction of the air to solids ratio corresponding to a maximum p(SO3) value, for a given concentrate and temperature, is of importance in fluidized bed roasting, since this could be associated with the formation of a maximum quantity of CuS04. Calculations are presented which predict this air to solids ratio, not only for a given concentrate composition, temperature, and pressure, but also for air which is enriched with sulphur dioxide or oxygen.

Jan 1, 1968

The following notes apply more especially to the purchase of silverlead ores produced in the neighbourhood of Zeehan and Dundas; for it is this class of ore that is principally mined in those parts, and which creates competition among the ore buyers.In the early days of this field, most of the ore passed through the hands of the first buyer who had sufficient enterprise to establish himself at Zeehan but in more recent times, competition has been so keen that there are generally three or four buyers tendering. lf the output was large this would not matter so much from the buyers' point of view but when we consider that the output of the field is only some 1,650 tons per month, and that of this 70 odd tons are produced by the Western and Montana mines, aud being sent home for realization, is withdrawn from local purchasers, there is really not enough for four buyers, especially at the present exorbitant prices they pay the miners.Some of the mines have a fixed sampling day, on which it is tacitly understood that the ore buyers will attend. Others, such as Grubb's Silver Mining Oompany, No-Liability, send round a printed reminder, stating the quantity of ore, and the date of sampling.

By P Duplancic and C R Lilley, R Hudson, D Beck

For deep block and panel caving mines, undercut or extraction level instability can have as much impact on overall recovery as underbreak or the premature ingress of waste. If the area of the mine affected by excessive convergence is small, recovery is usually possible. However, there are several examples of entire blocks that were abandoned prematurely due to footprint collapse. Clearly, such global instability has a major impact on recovery and must be avoided – this is one of the essential tasks for the design team.The design problem is complex. The planning engineer must ensure that the footprint has sufficient capacity to withstand the maturing loads in the cave, accounting for the effects of stress path, geological structures and the rock mass conditions. These are often uncertain and only sometimes quantified.The demand on the footprint will also be influenced by decisions and actions taken during production, especially related to draw, which can worsen a developing problem. Perhaps most importantly, the design decisions that favour stability and lead to lower deformation also negatively impact on idealised cave flow. Many engineers aim to minimise the size of extraction level pillars, to improve theoretical future resource recovery but in fact this can reduce recovery if widespread deformation ensues due to the undersized pillars.In 2014, PT Freeport Indonesia undertook detailed numerical analysis to quantify the effects of variability in rock mass conditions and geological structure on overall footprint performance. The analysis accounted for a range of stress paths and maturing cave loading scenarios sourced from a calibrated whole-of-cave deformation-flow model. The intent was to replicate some of the diversity and distribution of pillar deformation outcomes that may be seen in practice at Freeport.The discontinuum finite element analysis was able to replicate damage localisation around persistent structures, a realistic distribution of drive deformation and show how small areas of instability can evolve into major problems if poorly managed. The limits of pillar size and ground support as solutions to a number of different instability problems was also investigated, showing that pillar size alone was not a sufficient remedy for all adverse circumstances.In this paper, we describe the workflow for numerical analysis of footprint deformation. We discuss the compromises and considerations for balancing the sometimes competing needs for efficient extraction levels pillars, ground support and prudent draw strategy.CITATION:Beck, D, Hudson, R, Wilson, A D, Duplancic, P and Lilley, C R, 2016. An investigation of factors affecting the long-term reliability of extraction level pillars in deep block and panel caves, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 295–304 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By K Gordon, A Black

Two remediation strategies have been considered to reduce the levels of acidity and dissolved metals in acid mine drainage discharging from Sullivan Mine, West Coast, New Zealand. The oxidising strategy involves adding alkalinity and dissolved oxygen (DO) resulting in the precipitation of metallic oxides and decreased acidity. The reducing strategy involves removing DO, resulting in the precipitation of metallic sulfides, followed by addition of alkalinity to decrease acidity. Field remediation trials indicate a reducing system may be more effective for this site than an oxidising system. A residence time of only two hours in the limestone layer of a successive alkalinity producing system (SAPS) is sufficient to reduce acidity by 100 per cent, iron by 71 per cent, aluminium by 59 per cent, nickel by 38 per cent and manganese by 26 per cent. The proposed remediation plan will likely include a series of SAPS, followed by an anoxic limestone drain, and settling ponds to capture any remaining precipitates.

Jan 1, 2003

By Fardy J. J

Abundance data are presented for a comprehensive range of elements in oil shale samples from deposits located in Queensland. The techniques of instrumental neutron activation analysis and spark source mass spectrometry were used to obtain concentration data for up to 50 trace elements in each shale. These techniques were supplemented by other spectrometric methods to obtain data for major, minor and some trace elements. Sixty-four elements were determined quantitatively. This comprehensive characterisation of oil shale samples from the major deposits in Australia provides inorganic abundance data not previously available. It also provides important background information for processing studies and the associated environmental aspects of shale oil production and waste disposal.

Jan 1, 1986

The need for the hydraulic transportation of coal in the New South Wales coal industry, both from the coal face to the surface and from the coal mine to the consumer or the port for export, is explained. Details of research projects currently in progress and involving the hydraulic transportation of New South Wales coals are given together with information on the hydraulic transportation of coal in the United States of America. The potential of hydraulic transportation as a viable alternative to the proposed expansion and upgrading of the New South Wales railway system to meet the projected New South Wales coal production to the year 2000 is described.

Jan 1, 1980

By Edwards A. B

Occasional, sporadic and small occurrences of lollingite in the Broken Hill lode have been described,(l) mostly in the garnet sandstone in the foot-wall and under-wall of the Broken Hill lode. The lollingite contains appreciable percentages of cobalt and nickel and is regarded as an early mineral in the development of the lode; and, with the incoming of the sulphides, it has suffered considerable replacement by arsenopyrite. During the conversion of iron arsenide into the iron sulpho-arsenide, ilie nickel and most of the cobalt are removed in solution and are inferred to reappear in niccolite and other minerals that have been recorded among the later minerals of the Broken Hill lode. As a result of observations of the officers of ilie Broken Hill South Ltd., an occurrence of cobaltite can now be recorded which has developed by an analogous type of replacement.Cobaltite has previously been recorded from the Australian Broken Hill Consols lode in the vicinity of the rich deposits of silver, though not in contact with them. Cobaltite has been found in the northern extremity of the No. 2 lens of the Broken Hill lode at the 1,480 feet level of the Broken Hill South...

Jan 1, 1944

Macraes Mining Company Limited operates a 2.1 million tonnes per annum gold processing plant at Macraes Flat, Otago. This uses a conventional CIL route to treat oxide ore, and a flotation, grind, CIL route for sulfide ore. This paper describes the design and operation of this process plant.

Jan 1, 1992

Geological maps, data, and prospectivity analysis relevant to mineral exploration in New Zealand have recently been released. Regional-scale geological mapping is increasingly available for the country through the QMAP 1:250 000 Geological Map of New Zealand programme. Published QMAP sheets Greymouth, Wakatipu, Waitaki and Dunedin cover large areas of interest for mineral exploration companies. The QMAP geological data are also available in digital form for use with other digital datasets using GIS software. Crown Minerals, in cooperation with GNS, have completed two gold prospectivity studies; the first covering mesothermal gold in the South Island, and the second encompassing epithermal gold in northern New Zealand. These studies have defined areas of interest for these two mineralisation types and assembled geological, mineral occurrence and production, geochemical, geophysical, topographic and cultural data into projects for use with GIS software. Included are the results of prospectivity modeling for gold using these data and specific mineralisation models. The prospectivity studies and relevant data are freely available on CD through Crown Minerals and are intended to encourage mineral exploration in New Zealand.

Jan 1, 2003

By Giannini M

Of the optimization techniques proposed in determining the optimum open pit limits, dynamic programming and graph theory have proved most successful. However, publications on these two methods lack a certain amount of rigour and clarity in exposition. Certain ideas in the methods have been clarified and additional features introduced in order to make them more sensitive to practical applications. A case study in the form of an application of these ideas on data from a producing mine is presented and discussed.

Jan 1, 1986

The purpose of this paper is to outline current research on the Paparoa and, at the request of conference organisers, to present a general introduction to the geology of the Greymouth Coalfield as background to more specialised papers. Few results of my present work will be given; these can be presented at the next conference. Briefly, the research aims for an understanding of the controls which depositional environment has exerted on coal character, to be reached by a study of coal type and thickness, shape and extent of seams, integrated with a basinal analysis of the coal measures. An accurate description of the coalfield in these terms should facilitate prediction of subsurface trends, with possible application to the planning of drilling programs, and to mine development. Although study of Paparoa coal types is included here as only part of the research, coal type should be recognised as an important concept which has until revently been almost entirely neglected in New Zealand.

Jan 1, 1979

Copper Extraction from Scrap Cables by Biotechnological Means

Sep 13, 2010

The Telfer main dome open pit is operated by Newcrest Mining Limited at a current production rate of 50 Mt/a from a pit dimension compromising 2 km strike length, 1 km width and 250 m depth. As part of the refeasibility of the Telfer operation undertaken early this decade, Newcrest identified that an underground sublevel cave (SLC) operation along with an increased scale of open pit would support a new plant targeting the processing of gold and copper ore at 17 Mt/a rates. The SLC was initiated in late 2006 and broke into the open pit in late 2009. This situation is unique across the mining industry where a cave breakthrough was planned and occurred within an active large open pit operation. The SLC broke though into the west side of the Main Dome open pit into a specially prepared bench that was left at the 5384 RL of cut-back stage 3. A main haulage ramp is within 100 m from the edge of the cave breakthrough zone and this ramp passes down to the active levels which are progressing toward the 5200 RL. This paper presents insight into the mine planning and risk management associated with continued operation of the open pit operation while an active SLC breaks through. The cave breakthrough presents unique areas for risk management as there is potential for rapid propagation and subsidence. To support the undertaking, mine design and major hazard management planning has been carried out. Focus areas include; dual ramp system design, preloading the breakthrough area, monitoring of cave propagation and air gap using a seismic system and deep hole extensometers, wall stability and subsidence monitoring using radar and prism systems, and key trigger and response planning.

May 1, 2010

By E Breese

The Grey River dredge is the first large scale alluvial operation to be permitted under the Mining Act 1971 and the Water and Soil Conservation Act 1967. The experience of Grey River Gold MiningLimited in pursuing these statutory approvals has identified weaknesses and strengths in the present system and problems which need to be resolved. The Company has learnt lessons, which if heeded, will assist future large scale alluvial mining projects.

Jan 1, 1989

The following data are put together to assist those who are responsible for ordering stores for mines and works. When making out a list of mine stores for a new plant, one can hardly be expected to remember everything, still it is all the more important that articles should not be forgotten, should the mine be situated in an out of the way place, where the manager has to look several weeks ahead. A man who has been accustomed to buy stores on a small scale, from local merchants, where he could pick out personally what he wanted, may suddenly find himself in a place where he has to order wholesale quantities or make out store lists to send contractors for quotations. As it is of course cheaper to purchase stores by the hundredweight, coil, barrel, etc as the case may be, in which they are made up, than to break such a parcel, the way in which the materials are placed on the market is mentioned, so that those who don't know may take full advantage of wholesale terms. The most frequent sizes and brands employed in connection with Australian mining are also mentioned. It would be useless to enumerate all sizes made by the trade, as many would be of no value for our purpose; still I have put down what will serve as a reminder to the manager to mention what size he requires when giving an order, such as the diameter of dynamite cartridges a slight neglect of this sort has often caused serious delay. By mentioning certain brands I do not wish to recommend them in preference to others inadvertently omitted they are simply mentioned as some of those frequently met with.

By Sie A

After completing a feasibility study in 1987, Niugini Mining Limited (NML) obtained five Gold Mining Leases within PA 632, covering the Mount Victor and Clarkes Ridge gold deposits. Reserves prior to mining were 260 000t at 3.63g/t Au for Mount Victor and 40 000t at 2.8g/t Au for Clarkes Ridge. Ore was mined from the two deposits by NML from November 1987 to January 1990. A total of 645kg of gold and 346kg of silver were produced from 198 000 tonnes of ore pro- cessed. Mining and milling operations ceased in February 1990. Since then, there has been significant progress in rehabilitating and revegetating the site. Plant and workshop facilities have been dismantled and removed from site, exposed parts of the pit have been landscaped and replanted, tailings water has been neutralised and discharged, and the dam filled. All remaining personnel and equipment left the site in November 1990. It is envisaged that the replanted areas will be rapidly revegetated, leaving little evidence of mining. Niugini Mining did not recoup the initial investment for Mount Victor, but the mine produced a positive cash flow and made a significant' financial contribution to the local communities and Papua New Guinea as a Whole.

Jan 1, 1991

By H Bibby

Initial analysis of Long Offset Time Domain Electromagnetic (LOTEM) data has traditionally been made in terms of early and late time apparent resistivities. By using more than one grounded bipole as a source, a tensor analysis technique analogous to the method used to analyse DC resistivity multiple-source bipole-dipole surveying may be formulated. We define the æinstantaneous apparent resistivity tensorÆ as the tensor that relates the total electric field vectors at each instant to the steady state (DC) uniform half space current density vectors due to each source. Instantaneous apparent resistivity tensors calculated for a 3D resistivity model suggest that profiles of LOTEM measurements across simple 3D structures can be used to create an image that reproduces the main features of the subsurface resistivity. Where measurements are distributed over an area, maps of the tensor invariants or the tensor ellipses at different times can be made into a sequence of images which provide a way of ætime slicingÆ down through the target structure.

Jan 1, 1996

By R Tweedie

'The politics of mining in New Zealand' is a topic I chose myself because of its importance in the future of the New Zealand mining industry. There are many people in the industry who are cynical about politics, cynical about politicians and definitely cynical and often critical of political decisions. In fact, many industry people say they don't want to get involved in politics, they just want to get on with the business of exploration or mining. The point of my address is that politics is important and the industry cannot afford not to participate in the political process.

Jan 1, 1991

By L Barro

There is currently a worldwide interest in coal-oil technology as the search continues for alternative energy sources to reduce the consumption of petroleum crude. An important aspect of this coal-oil technology study is to obtain information on the flow properties of coal-oil slurries. While some work has been reported on the flow behaviour of black coal-oil suspensions, very little work on brown coal-oil suspensions has been reported. In this paper flow characteristics of brown coal-oil suspensions for various coal concentration and temperatures have been presented. A capillary rheometer, designed to handle settling suspension, has been used for determining rheological properties. Brown coal of 0.0725 mm average particle diameter has been used in this work. The oil was a coal derived product having a boiling point range of 234¦C - 319¦C. Apparent viscosity of all suspensions was found to increase on storage due to ageing. Ageing might have occurred due to physicochemical interactions between coal and oil. Flow behaviour of some suspensions changed from Newtonian to non-Newtonian on storage. Apparent viscosity increased sharply with increase in solids concentration and suspensions at higher concentration behaved as non Newtonian liquids. Viscosity decreased with increase in temperature; rate of decrease slowed down with increase in temperature.

Jan 1, 1980