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It is very rare in the underground hard rock environment to find a deposit that is ideally suited to a specific mining method. Usually the irregular shape of the orebody will allow the deposit to be extracted by more than one mining method. During the prefeasibility stage, a number of conceptual mine designs are generally evaluated to see which offers the best method of extraction for the deposit. The selected method is usually based on key decision criteria such as the overall extraction of the orebody, the amount of metal produced annually and the unit cost of production. Often the prefeasibility study document will state that the project has an NPV of æxÆ million dollars. This statement can be made without any quantitative consideration of the likely risks of the mining methods reviewed or the level of confidence in the estimation of the NPV. By assigning a probability of failure to each component of the mining cycle a measure of the risk for each method can be determined. One mining method may provide the highest NPV when it is performing well, however, there may be a higher risk of a major failure impacting on the performance of that method, eg the failure of a mass blast of a crown or rib pillar. This paper will present a flowsheet approach to the use of risk analysis for determining the likely production rates of different mining methods. This framework allows the annual metal output to be estimated and from this the NPV for each method. A level of confidence can be applied to the estimated NPV for each option. An example will be presented on how this technique has been used within the Normandy Group.

Jan 1, 1998

A minimum target of economic growth in Australia has been set at 5% per annum growth in G.N.P. at constant prices (Vernon Committee). 2. The core of the problem of sustaining steady growth at this or a similar rate is to ensure regular flows of investment. This sustains productivity, helps to control balance of payments pressures, and to check inflation. 3. The regular intake of human and physical resources, in conjunction with intensive capital development involving finance, technology and management, is basic to sustaining the growth rate and ensuring rising standards of living.

Jan 1, 1971

By Nilsson C

Man has always been and will always be part of his environment, in ,a good, bad or indifferent manner. Until quite recently, this environment has been the atmospheric boundary layer above the land masses, and to a limited extent the air-sea interface of the oceans. Since the days when he lived in caves, he has built up a wealth of observations on these two environments,-with ever-increasing scientific precision which unfortunately until quite recently was completely insufficient for modern capabilities of data analysis. Consequently, in a sense, he has left in his wake thousands of years of missed, opportunities for making exact observations and increasing his understanding. The data of the past are lost and he has to be satisfied with what he can assemble from now on when his environ- ment, largely as a result of his actions, is exhibiting more and more rapid variations in time; in other words, time series of observations of phenomena are required, the length of which is critical for most purposes of analysis.

Jan 1, 1970

By J Li, A McFarlane, J Yu, L L. Kuhar, R Meakin, N Chapman

"Column leach tests are used frequently to predict recoveries and reagent consumption for nickel laterite heap leaches. These column leaches often run for more than 100 days and therefore require long-term monitoring and data analysis to achieve the desired information. To minimise the cost and time required to obtain relevant information for nickel laterite heap leaching, we have developed a small-scale hydrogeometallurgical laboratory test to serve as a proxy to column, and by inference, heap leaching. In excess of 50 leach tests were conducted using four different small-scale proxy and column leach tests to compare predicted nickel recoveries, acid consumption and leach kinetics and to determine whether insight into potential scale-up effects can be obtained. The most promising proxy test was identified and we achieved a statistically significant recovery and acid consumption correlations between this test and the column leach tests. The accuracy of the small-scale tests was confirmed by column tests run on new laterite ores. This geometallurgical proxy could be of use for the population of block models and process selection during the mine planning phase or for optimisation and control during processing.CITATION:Li, J, Kuhar, L L, Meakin, R, Chapman, N, McFarlane, A and Yu, J, 2016. A Geometallurgical Proxy for Nickel Laterite Heap Leaching, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 335–340 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

The five main ways in which coal is used are1. for electricity generation,2. as a lump fuel for domestic and industrial purposes,3. for gas making,4. for making carbon for chemical and metallurgicalindustry, and5. as a source of coal tar and coal-tar chemicals.In the past about 80 per cent of Victoria's brown coal has been used for power generation and the rest for making a lump fuel, in the form of briquettes. Some of these briquettes have been used for gas making, and a carbon industry based on them has recently been commenced, and could expand rapidly. However the enormous increases expected in power requirements, approximately a doubling every 10 years, will ensure that even if the manufacture of carbon increases dramatically and a large amount of coal is used for other purposes, the brown coal industry will always be dominated by power generation. As new fuels such as natural gas, oil, and nuclear fuel become available at competitive prices these will take their share of the power generation load.Natural gas or oil, or possibly pumped storage hydro, will almost certainly be used for all future peak-load stations, comprising around 40 per cent of the total installed generating capacity, but new base load stations will continue to be designed for brown coal operation until about the mid-1980s, by which time nuclear power stations will become competitive. By this time Victoria will have installed about 6000 MW capacity of brown coal stations, burning around 50 million tons/year of coal, compared with 18 million tons/year at present, with perhaps 15 million tons/year being used for other purposes.This consumption of 65 million tons/year should then remain fairly stable over the life of the power stations installed, well into the 21st century. Brown coal therefore appears to have an assured place in providinga major part of Victoria's fuel requirements, despite the diversification in fuel usage pattern which appears certain to occur with the recent developments in new fuel resources.

Jan 1, 1971

By P F. Hodkiewicz

"Our understanding of mineral resources relies on three basic steps: data capture data interpretation model construction. Until recently, all three of these steps required significant time and manual effort to produce a single resource model for mine planning, typically taking more than a year to progress from drilling to the final block model. Over the past several years, BHP Billiton has been developing innovative workflows in rapid resource modelling projects to significantly reduce these time constraints and make the process more productive by replacing manual activities with automated ones. Rapid resource modelling is the process of combining recently developed off-the-shelf technology with internal technology developments to fundamentally change the way we collect, interpret, model and evaluate geoscience data. Initiatives include automated systems and standardised workflows to make it safer, faster and cheaper to continuously update multidiscipline resource models. Specifically, rapid resource modelling workflows combine: real-time analysis of drill holes and drill samples with downhole tools and hyperspectral scanning systemsautomated interpretation of drill hole intervals based on pattern-recognition algorithmscontinuous modelling workflows using implicit modelling software. This paper outlines technology developments and workflows that provide a more thorough understanding of mineral resources to support faster and more informed strategic, planning and production decisions.CITATION:Hodkiewicz, P F, 2014. Rapid resource modelling – a vision for faster and better mining decisions, in Proceedings Ninth International Mining Geology Conference 2014 , pp 183–188 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 18, 2014

By T Hodgkin

The WA Goldfields is a highly productive gold and nickel mining area, but is arid with highly saline groundwater. Groundwater is widely used to supply process water to mines in the region but high groundwater salinity, commonly exceeding 50 000 mg/L TDS, tends to increase processing costs, limit end uses for the water, cause problems with disposal and potentially increase impacts on a sensitive arid environment. The area has low rainfall (200 - 270 mm/year) but run-off, particularly during cyclonic events, is high. Our experience suggests that stream flow from catchments in the area can produce a divertible yield of 8 - 17 ML/km2/year. An evaluation of stream flow harvesting using AnglogoldÆs Jubilee Pit predicted that 1000 ML/year of good quality water could reliably be supplied to the Sunrise Dam Gold Mine. Because of high rainfall variability, it is likely that an alternate source of water supply will be necessary when operating a surface-water harvesting scheme in the WA Goldfields. However, a combination surface/groundwater supply could have substantial cost, operational and environmental benefits compared to traditional supply systems that utilise groundwater only.

Jan 1, 2003

Longwalling has reached a high standard both in Germany and Australia and most improvements should be expected in planning, monitoring and control. Double drum shearer have electric drives to 1000 kW and automatic height control is under development. Conveyor pans to 40mm thickness and chains to 2300 kN breaking load are in use with controls for pretension and load compensation under test.Trends in support are towards two leg shields with loads to 3850 kN per leg and electrohydraulic controls. Expert systems have been devised for planning and diagnosis tasks. With increases in technical standards, staff qualification standards at rising too, drawing attention to training requirements for modem personnel.

Jan 1, 1991

By Mandzic E. H

The Dome Mine of Timmins Mining company is located in South Porcupine, N.W. Ontario. The orebody being mined partially lies in the No. 3 shaft pillar. Stability analysis has been carried out to establish the influence of nearby mining on ground movement in the shaft vicinity. Mathematical modelling of shaft displacement has been done for stope layout at depths from 180-210 m and distances of 10-50 m from the shaft. Analysis indicated that ground displacement around the shaft is below 1 mm/m and one third less for cut and fill than in the case of open stope mining. The result of the investigation was later confirmed by cut and fill mining of this orebody.

Jan 1, 1986

By Anylmore M, Walker A, Fletcher A

Roasting of sulphide and sulph-arsenide gold ores produces unwanted emission of sulphur and arsenic oxides, and a less than complete recovery of gold. Pyrite loses sulphur and arsenopyrite loses arsenic at a useful rate at temperatures of 600¦C and above in an inert atmosphere. Sulphur and arsenic driven off can be condensed before entering the atmosphere. During the process, solid-solution gold redistributes itself on internal surfaces of the resulting iron sulphide. Two subsequent processing options may be used; direct cyanidation of the porous sulphide resulting from the anoxic pyrolysis, or a second-stage roast to oxidise the remaining iron sulphide. The first option may be viable under certain conditions of pyrolysis. The two-stage option has an environmental advantage over the traditional roast because it reduces oxide vapour emissions by 50 per cent. The second stage may provide nearly enough energy to sustain the entire process.

Jan 1, 1992

By Mould GR

Gas drainage has been practiced for many years mainly for safety reasons in various countries in Europe, in the U.S.A., the U.K. and Japan. Legislation has been developed to control the production, transport- ation and utilisation of methane and associated gases. Gas drainage is now being carried out at some Australian Collieries, but as this is a new venture little specific legislation is available. This paper briefly describes the drainage methods and legislation applied overseas, gives a brief history of gas drainage in N.S.W. and indicates the deficiencies of the present legislation. It outlines the approach to new legislation which will deal comprehensively with gas drainage operations and utilisation in New South Wales.

Jan 1, 1982

By S D. Fox, P B. Swart

Statistics showing that mine rehabilitation is falling behind rates of disturbance continue to be reported in the media. Unfortunately, most reported statistics do not account for the large growth-cycle that mining in Australia experiences, where there are typically significant new disturbances with large portions of these areas not being available for rehabilitation for a number of years. Many commentators assert that better planning is required to ensure that rehabilitation will be able to achieve a safe, stable, non-polluting landform that meets the agreed post-mining landuse.This paper focusses on the revegetation aspects of mine rehabilitation and in particular the matters that need to be addressed in the planning stage so that revegetation success is ultimately able to be demonstrated to regulators and other stakeholders.CITATION:Fox, S D and Swart, P B, 2018. Planning revegetation for relinquishment, in Proceedings Life-of-Mine 2018, pp 113–115 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

The writer had the pleasure of several months' laboratory tests on a metallurgical process for copper ores devised by Mr. W. H. Corbould, Consulting Engineer, North Queensland. Mr. Corbould's research work in this direction commenced somesix years ago, and he eventually succeeded in obtaining a good extraction of copper and a resulting solution practically free from iron and other impurities. The commercial operation of the process was investigated and special machines with novel features were designed. OUTLINE OF THE PROCESS.The process described in detail in the following pages, required for successful application that the ores contain at least the minimum ratio of sulphur to copper, consistent with the production of sulphadising roasting conditions.

Jan 1, 1921

By K Devencorn

The development of robust, economical transport infrastructure has been identified as a key driver to sovereign economic growth. Notwithstanding the value of undeveloped mineral resources, unless they can be brought to market they are of little value. Within a global context, the continent of Africa probably faces one of the most significant transport driven economic development programs as countries strive to unlock their much sought after resources.The UN’s Africa Review Report on Transport (United Nations Economic and Social Council, 2009) provides an excellent context for the issue facing African countries and the potential for investment in transport to solve many of the intrinsic problems they are confronted with. With little exception, economic development in Africa is very likely to be driven ‘off the back’ of transport development – and more specifically from heavy-haul rail as a means by which economic wealth can be derived from export of the continent’s vast natural and mineral resources to the world. The report found:transport is a key driver of economic development and poverty reduction;road transport is the most dominant mode in Africa;the ‘Cost to Market’ of African goods is hampered by the reliance upon road transport;the cost of road transport is not just economic – 19 per cent of the world’s road fatalities were recorded on African roads;African railways are seen to be disjointed and under-utilised;Africa’s ports are key to export trade - yet only six ports (three in Egypt, and three in South Africa) handle about 50 per cent of the continent’s total container traffic;the cost of transport is increasing making African trade even less competitive; andsignificant negative impacts of Africa’s reliance on road transport – health, and greenhouse emissions.We understand that mining the resource is only part of the solution – it has to be put to market at a competitive landed cost.Most African countries face huge costs associated with transport development and ongoing operation – in many cases beyond their available resources.The Australian rail industry has faced and solved many of these challenges.

Nov 22, 2011

By Amos QG

The Paddington I and proposed Paddington II Pits are both located in what is, by Eastern Goldfields standards, a large tonnage-low grade orebody. The Pits have been designed to supply ore to a substantial Treatment Plant at the designed rate of 875,000 tpa. (This throughput is currently being increased to 1,200,000 tpa).Generally the orebody lends itself to large tonnage mining techniques, relying on only a relatively small amount of sampling. The surface enrichment zone and depleted zone are reasonably complex and require more intensive grade control and sampling techniques as typically utilised in many surface mines in the Eastern Goldfields, although as experience and understanding of the nature of the orebody was gained, less sampling became necessary.

Jan 1, 1986

By Ellicott C, Webb N

In November 1996 the NSW Minister for Mineral Resources, Hon Bob Martin MP, commissioned ACiL Economics and Policy Pty Ltd to conduct a wide ranging review of safety within the New South Wales mining industry.The review was a response to a disturbing number of fatalities which had occurred in the industry during the Minister's term of office together with a number of alarming near misses where serious failures in mining systems had occurred. Shortly after the review was commissioned, four mine workers died at Gretley Colliery near Newcastle. An inquiry is currently being conducted into the incident.

Jan 1, 1998

By Denholm W. T

The SMELT-2 package is specifically designed to perform on-line simulation of smelting processes. This paper describes its application to the simulation of continuous matte converting followed by reductive slag cleaning in SIROSMELT reactors. The matte, containing 50% Cu is assumed to be produced at the rate of 20 tph in a continuous matte smelting furnace such as an Outokumpu Flash Furnace, Noranda or Sirosmelt reactor. Two alternative fluxing strategies in the converter are examined, namely: ò conventional silicate slags, ò calcium ferrite slags, and the flow sheets associated with each strategy are discussed. A regular solution model is used in the present study to account for the variations in the activity coefficients of components in the slag.

Jan 1, 1989

By B Stewart

The SRS-1200 concept came about following the recommendations from the Board of Inquiry into the 1994 Moura No 2 mine disaster with the aim of having a system to remove personnel from an unsafe environment underground via a shaft where no other means of escape is possible. It is a mobile rescue unit that utilises a winding system to operate a man cage. It can descend the cage up to 1200 m into a vertical shaft. This operation is managed from the winder control compartment located on the non-driver side at the rear of the vehicle.

May 5, 2022

Swedish sulphide mining is presented. Dry filling is described. Fill properties with and without cement addings are dis- cussed in relation to various studies in la- boratory and in situ.

Jan 1, 1973

By P Oikkonen

Sprayed concrete has played an integral role in underground rock support for nearly a century. However, concrete is also considered to be one of the biggest environmental problems in construction and mining, largely because of the high carbon footprint of cement and aggregates production. This is driving the industry to find ways to cut concrete usage where possible. Improving sustainability by cutting concrete material consumption also reduces application time and costs. Improving concrete properties can make it possible to design thinner linings, but as awareness of safety and longer design lifetimes are driving developments in the opposite direction, it is not realistic to see this as a major factor in cutting concrete consumption. More accessible solutions are focusing on layer thickness control and minimising rebound and wastage. Digital technology and innovation offer excellent tools for improving sustainability while optimising other aspects of the spraying process at the same time. A digital layer thickness control system gives near-real-time information to the sprayer operator with full coverage of the sprayed surface. This enables the operator to achieve consistent layer thickness on the first pass, in comparison to the traditional methods of overspraying with the aim of achieving sufficient layer thickness, probe drilling after the concrete has set, and respraying at a later stage if needed. Operator competence is the single biggest variable in a successful sprayed concrete process, affecting rebound and wastage levels. Unfortunately, the learning curve to become a master sprayer is quite steep and training on a real sprayer and real concrete requires a significant amount of time and money. Training in a virtual reality (VR) environment enables operator training to be carried out in a low-risk environment and provides a way of measuring performance and assessing and certifying the operators. After the VR training period, a novice nozzle operator has the basic understanding to start working on a real sprayer, and an experienced nozzle operator can benefit from the possibility of assessing their performance.

Mar 29, 2023