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THOSE who dabble in m.ining are no exception to the general rule that persons who know a little of a subject are apt to think that they know all about it. Some colour may be lent to the belief that anyone may succeed in mining when we hear stories ofsuccessful diggers and others who have accidentally dropped on to something good through no foresight on their part; but we seldom hear the contra account of the far larger number who fail. Those who go more thoroughly into the subject, and take up mining as a profession, know very well that it is not one that can be carried out successfully by rule of thumb, but when they point this out to the public they are credited with trying to make it a closed profession; and outsiders are for ever trying to find out the 'trade secrets,' at the same time spurning the main one, which is hard study, experience, and the ability to apply their knowledge.The average mining man is not rich. When he amasses a fortune it is generally through speculation rather than professional work, thought no doubt his technical knowledge may have assisted him. However, making a fortune and running a mine are twodifferent things.

Jan 1, 1911

The integration of economic, cultural, social and environmental decision-making has increasingly become globally recognised as the only acceptable way of doing business consistent with sustainable development. This concept requires a move to a new economy, where environmental, cultural and social issues are accounted for and integrated in business decisions and practice. There has been much discussion on sustainability and sustainable development, but organisations are still grappling with what this means in reality for their business and how they should respond. The challenge is to take the way we do business to a new paradigm and make solutions relevant to business. This paper will look at some of the strategies and programs being adopted or considered by resource companies as they move towards a more sustainable future. These include defining a sustainability framework for their organisation, developing the business case and planning approach. Also included is a brief overview of some of the new approaches to environmental management, such as reducing materials and energy intensity, minimising or eliminating impacts through better waste and emissions management and process control, taking a whole of life approach to products and conserving resources. The concepts of Product Stewardship, Eco-efficiency and Cleaner Production will all be discussed.

Jan 1, 2002

By R Gilbertson, N Freeman

Metallurgical accounting is key to the control and production planning process of any mining operation. This is even more crucial for complex operations involving mining, concentration, smelting, refining and marketing. The tracking of multiple metal product and contaminant components through the operation can improve process predictability and inventory management. Appropriate use can be made of æhigh quality dataÆ for strategic reserve utilisation, mining operations, milling operations, etc. This information enables the optimisation of all aspects of the mining and processing operations. This case study discusses a metal balance implementation for WMCÆs Olympic Dam operations; a large integrated mining, concentration and refining operation, which used an existing off the shelf statistical data reconciliation package developed for the oil industry. It was extended to track and balance the metal co-products across the entire integrated mining, mineral processing and refining plant. The key benefits discussed are tight integration with existing data collection systems, formalisation of previously informal processes, and leveraging the development and support available for a widely used package. The project provided a solution for the site metallurgical balance spanning the mine and processing plant. The solution facilitates a bridge between the planning and production worlds, using a common data model across the site.

Jan 1, 2002

By N J. Beukes, J Gutzmer, C Reinke, M Bau

In this study the light sparse phase search (SPL_Lt) mode on the Mineral Liberation Analyser (MLA) was successfully used to identify and quantify the abundance of rare earth element (REE) phosphates in Precambrian iron formations. Monazite (light REE phosphate) and xenotime (Y and heavy REE phosphate) are identified and data from the MLA combined with the mineral chemistry of the two minerals are used to calculate and model the expected REE concentration and distribution in these two REE phosphates. The REE phosphates account for up to 31 per cent of the REEs in the banded iron formations (BIFs) and excellent correspondence is observed between the modelled REE patterns and the whole rock geochemical data available for the same samples. Except for quantifying the mineral weights, the sparse phase search also allows for the localisation of REE phosphate grains and the observation of their association with other minerals using backscatter electron (BSE) imaging. These observations are used to conclude that the REE phosphates were most likely of diagenetic origin, with REEs and phosphate remobilised from primary chemical precipitates. It is demonstrated that automated mineralogical techniques can be used to qualitatively and quantitatively describe the influence of a rockÆs trace mineralogy on its geochemistry.

Jan 1, 2008

Vatukoula is a gold mining township situated at the south-west periphery of a Tertiary caldera which measures 3 miles by 4 miles. Erosion of the caldera resulted in the formation of a topographic depression, called the Tavua basin, covering about 30 square miles. This area, also known as the Tavua Goldfield, has been the site for spasmodic prospecting since the initial discovery of gold in 1932.The mineralization at Vatukoula is typically epithermal with the gold occurring as tellurides, auriferous sulphides, and to a much less extent as native gold. The lodes are confined to three major structures i.e. north-west shears, flatly dipping structures (flat makes), and local shatter orebodies.Within these structures, at least five types of controls are recognized to account for the localization of the oreshoots. The dominant control is structure.The lode structures are related to the overall structural pattern of the Tavua basin. This pattern, which is controlled by the collapse planes of the caldera and a north-west shear system, produced a "shatter block" atVatukoula and elsewhere around the caldera.Structural analysis indicates there are certain areas in the Tavua basin where exploration could be rewarded by the discovery of orebodies with similar controls to those of the productive Vatukoula block.

Jan 1, 1967

By W Dodson

Major ions, d18O and d2H and Carbon-13 concentrations in groundwater from 30 bores near an open pit iron ore mine were used to better understand the chemical evolution of groundwater in the aquifer. The relatively depleted d18O and d2H isotopes of groundwater from various depths suggest that groundwater is recharged from intense rainfall events, with little evaporative effect. The 300 to 500 mg/L increase of major ions relative to that of rainfall is due to evapotranspiration of rainfall during recharge. Geochemical mass balance modelling suggests that the evapotranspiration of rainfall during infiltration through the unsaturated zone varies over six fold from 20 to 130. This coupled with the dissolution of CO2 from the unsaturated zone and partial dissolution of carbonates and gypsum from Tertiary sediments and carbonates from the Wittenoom Formation accounts for the current major ion, d18O and d2H distribution in groundwater. Despite the relatively dissected morphology and steep hydraulic gradient the results of this study highlight the dominance of vertical flow relative to horizontal flow. The study also shows the dominance of rapid recharge by significant rainfall events as an important component of the water budget for east Pilbara aquifers.

Jan 1, 2009

In current mining practices it is desirable to bring about a substantial increase in both rate of face advance and productivity, thus compelling the mine engineer to consider better and more productive ways of mining. Transportation plays a vital role in achieving improved productivity. This paper focuses on horizontal transportation systems. Horizontal transportation is defined from the shaft station area to the end of the stope cross-cut. Traditionally, horizontal transportation is inefficient in comparison to vertical transportation efficiencies and accounts for a high proportion of South African mine accidents. Thus, the role of horizontal transportation has been investigated in detail, as it offers the greatest chance for improvement. The purpose of the paper is to provide a best practice guideline for the design of horizontal underground transport systems. It is intended that the document be used by mine designers and planners as an aide memoir during the design process and benefit may well be gained from retrofit and reorganisation activity. The paper looks at transport systems suitable for deep level gold mining in South Africa and evaluates such items as management, scheduling, and haulage systems. Current transportation systems for personnel, material and rock transportation are evaluated, gaps in technology highlighted, and recommendations made.

Jan 1, 2003

We often read and hear, especially in the United States, that we are running out of critical metals. These are vague forebodings of stagna- tion or winding down of our civilization. Our technological progress has been rapid in the last 50 years and is still advancing at an accelerated rate, and predictions of its long-term impact on consumption and production of metals are more hazardous than ever in the light of the great economic and political shifts that are bound to continue. There are many factors that will have a hardly predictable but profound effect on pro- duction and consumption of metals over a time span of, say, 25 years. Among such factors are recycling, substitution, availability of capital, direct involvement of governments in financing and production, and the capability of producing much lower grade ores at possibly much higher prices relative to costs in the event of scarcity. I must state at the outset that my discussion of this topic does not take into account the role that deep-sea nodules containing copper, nickel, cobalt, and manganese may play, because I don't believe production from these deposits will be of much significance within the 25 year span I will be discussing.

Jan 1, 1978

By Henderson J

Iron ore samples selected from the Deepdale, Iron Prince and Mt. Newman ore bodies have been pelletised on a pilot scale plant and subsequently reduced under laboratory conditions by hydrogen or carbon monoxide. Pellets approximately 1 cm in diameter have been reduced by hydrogen over the temperature range 5000- 900¦C and the results examined by thermogravimetric, microscopic, electron probe and x-ray techniques. After an initial time delay it was found that up to 95% reduction the rate of reduction could be described by a transport con- trolled porous model, in which the effective diffusivities of hydrogen in theòpr¦duct layer and the reaction zone are filar. Independent measurements of effective diffusivity supported the values obtained from the reduction data. ve 95% reduction the rate decreased markedly due to the formation_of retained wustite or fayalite. Comparison with reduction by carbon monoxide over the temperature range 7500 - 900¦C showed that the rate eduction by carbon monoxide was approximately five times slower than the rate by hydrogen. The rate of reduction was found to be a function of the properties of the pellets, which may account for the ely conflicting results that have been obtained in previous investigation on porous pellets.

Jan 1, 1970

By Peck RC

The ore body at Elura contains fine grained galena and sphalerite in a matrix which is mostly pyrite. A differential flotation circuit concentrates lead and silver in the first section and zinc in the second. The lead section, shown in figure 1, was sampled in detail previously and the metallurgical performance assessed on a size by size basis. That assessment took no account of liberation and given the fine grained nature of the ore body, this could lead to an incomplete picture of the flotation performance. Liberation measurements were made using the QEM*SEM system on four size fractions of samples taken from seven different streams in the lead section. Using the mineral flows obtained from the mass balance around the lead section an excellent liberation balance was obtained which enabled the effect of liberation on the flotation performance to be assessed. The measurements indicated that only 17 per cent of the galena and 28 per cent of the sphalerite in the flotation feed was liberated. On the other hand 31 per cent of the gangue iron sulphides were liberated. The final concentrate was largely composed of locked galena and locked iron sulphides with 85 per cent of the product being locked. There was a small but significant fraction of liberated pyrite.

Jan 1, 1991

By McDonough RJ

Mechanical agitation is the preferred system for Carbon-in-Pulp processes. Agitator design requires an understanding of the relationships between energy, shear and flow and the nature of shear rates and shear stress distribution in an agitated tank. Laser techniques are useful when studying these phenomena. The alternatives are open impeller agitation or draft tube circulation. Each has advantages and disadvantages but both require careful choice of impeller and system geometry. Overall the draft tube circulator is the more attractive in many cases. Open impeller agitators are designed in accordance with established procedures for mineral slurries taking due account of shear effects in tanks containing carbon. Preferred tank proportions are 1:1. Circulator design methods were developed in the alumina industry before being applied to CIP processes. Optimum draft tube diameter is critical to power requirements. The overall system must be designed as an axial flow pump operating in a closed circuit. Such a system exhibits quite characteristic behaviour which requires an impeller of varying pitch angle and aerofoil section for best stability and efficiency.' Tank height may be 2 or more times diameter. Resuspension of settled solids can be assisted by a series of slots in the draft tube. These slots have the secondary effect of stabilizing hydraulic behaviour and reducing installed power requirements.

Jan 1, 1982

By Maxwell HW

Pacific Coal Pty Limited (a wholly owned subsidiary of CRA Limited) managed the interests of six members of a joint venture formed to mine and export eight million tonnes of export quality steaming coal from a mine developed at Blair Athol in the Bowen Basin of the Central Queensland coal fields. The mine is now operated by Blair Athol Coal Pty Ltd. Crooks Michell Peacock Stewart Pty Limited (CMPS) was awarded a project management and engineering contract for the total mine portion. Following a feasibility study, CMPS carried out an Optimisation Study which produced changes to the design of the project, thus resulting in the project budget being reduced by some A$13 million. In spite of a number of late additions to the scope of work, the project was completed at a final cost of A$148 million, many millions below the reduced project budget. The project was also completed several months ahead of schedule. Total services were provided to take the project from feasibility stage through to the establishment of an operational facility and included project management, planning and control, accounting and financial control, as well as the organisation of engineering, procurement, construction, industrial plant commissioning, and technical training matters.

Jan 1, 1986

By P C. Hagan

Production scheduling is often reliant on an estimation of a mineÆs trucking capacity. While this mechanistic approach is relatively simple, it often over-estimates actual throughput resulting in under-utilisation of downstream process and a shortfall in revenue. An alternate approach has been developed that recognises the interdependency between processes in the mine production system including materials loading, haulage and crushing. This approach incorporates a heuristic model based on queuing theory that accounts for the variability in performance of individual processes and that this paper presents the results of a study comparing the conventional approach to mine scheduling with a capacity constrained model at a large open cut mine having a truck and shovel fleet. The capacity constrained model consistently predicted a lower material throughput compared to the conventional approach. Differences in throughput between the two approaches were found to increase with loading time, for example when loading time exceeded 3.9 minutes there was a shortfall of up to 40 per cent in estimated throughput. Longer travel times tended to ameliorate any differences. When applied to a mine schedule that extended over a two and a half year period, the difference was equivalent to a shortfall of nearly eight per cent in total material movement.

Jan 1, 2007

By Fuller P. G

The purpose and current practice of cable trusses in underground coal mines is briefly outlined and details of various cable truss designs are presented. The main part of the paper describes the in-situ performance of cable trusses installed as secondary supports in gateroads and recovery roads of longwall coalfaces. The performance analysis is based on the results of in-situ monitoring carried out at a number of sites at two underground coal mines within Australia. Truss performance has been assessed as load developed in relation to roof convergence, face position and time. Additionally, the influence of strata conditions, installation pattern/density, roadway layout and geometry have been taken into account. An analytical model has been developed to predict truss loads. The principal variables are listed and the basis of the model is described. Based upon behaviour observed in the field the model has been progressively upgraded and validated against measured performance. Guidelines on truss performance and factors which influence it are presented and the implications of these to the use of cable trusses is discussed. Possible methods for improving truss performance in certain strata conditions are outlined and some comments are made on the value of cable trussing compared to cable bolting in these Situations.

Jan 1, 1992

By Motyka J, Adamczyk AF, Witczak S

A case study of migration of a paper factory fluid wastes, on the distance of 5 km from an underground disposal site to an ore mine is presented. The ore mine in question, situated in SW Poland is pumping 3.5 m3/s (ca 300 000 m3/day) of groundwater, producing a cone of depression about 150 m deep and several kilometers wide. The migration of wastes (pollutant) occurs within the carbonate karstic aquifer of Triassic age. The aquifer is about 100m thick and is characterized by the coefficient of hydraulic conductivity equal to 8 m/day on the average. The results of systematic measurements carried out for 13 years enabled to estimate the mean breakthrough curve of the pollutant. On this basis and taking into account the coefficient of hydraulic conductivity as well as the mean hydraulic gradient between the disposal site and the ore mine, the migration parameters of the polluting material, i.e. the real flow velocity, the effective porosity and the longitudinal disper- sivity have been calculated. As the measurements considered a long migration distance of the pollutant, the obtained hydrodynamic dispersion constant (dispersivity), in the authors opinion, is reliable enough to be applied for regional groundwater calculations, regardless of the "scale effect".

Jan 1, 1988

By Whittaker B. N, Reddish D. J

The rockbolting method of support is employed widely in several countries in different of mines. Hard rock mines use this method extensively. Soft rock mines, such as coal mines, have employed standing supports (steel sets) as the main method, although some countries such as the U.S.A. and Australia have preferred rockbolting. There is increasing interest in extending the rockbolting method in coal mines. The application of rockbolting techniques in an industry which traditionally has not applied such techniques, has required the development of a systematic design approach. This design approach uses extensive monitoring, to asses the viability of the support system in differing conditions. Currently at a number of new and existing mine developments in the U.K., rockbolting is being successfully applied. Although, inevitably some localised geotechnical problems have been encountered and have needed to be taken into account. The effect of faulting on roadway conditions is discussed in this paper and a design approach has been applied using a numerical analysis method, namely the Finite Element Method. The results presented in the paper serve as a useful guide to roadway support designers, and in particular the role played by different bolts in a range of conditions.

Jan 1, 1992

By Nguyen G. H, Graham J

A laboratory-scale fluidised-bed roaster has been used to examine the effect of temperature and duration of roast on the morphology of the calcine produced from a pyritic gold-bearing concentrate. Two mechanisms of oxidation, which depend on the roasting temperature, have been identified. For samples roasted below 550°C, direct oxidation of the sulphide occurred to form hematite with a porous fine-grained concentrically-layered texture. The surface area of the calcine increased with an increase in roasting temperature in the range 400 to 500°C. For samples roasted above 550°C, the first reaction was the evolution of sulphur vapour to produce pyrrhotite, which underwent increasing grain growth as the roasting temperature was increased. This had the effect of decreasing the surface area of the calcine. The pyrrhotite was subsequently oxidised to produce hematite.Leaching studies using cyanide solution indicated that gold extraction around 95 per cent was achieved at temperatures of 500°C and above, with optimum extraction, taking into account rate and cyanide consumption in the range 550 - 700°C. Hence recovery did not decrease with decrease in surface area of the calcine. Observed gold in leached calcines was mainly enclosed in thin oxide walls of the hematite, with minor quantities enclosed in quartz and silicate minerals.

Jan 1, 1995

The metals titanium and zirconium and their alloys occupy individually unique positions in the catalogue of metallic materials available for engineering applications. Because of the uniqueness of their usage in the aerospace industry, in the case of titanium, and in the nuclear industry, in the case of zirconium, the except- ional resistance of both the metals to the majority of corrosive media is often overlooked. The cost factor in the application of these more exotic metals has, in the past, been a major considerat- ion in the rejection of titanium and zirconium as constructional materials in areas of usage where their superior corrosion resistance strongly favoured them over more conventional metals and alloys. The cost differential, vis-a-vis austenitic stainless steels, for example, is not a trifling matter, being of the order of 6 : 1, when compared on a weight basis. However, if one considers the cost, for, say, sheet product on an area basis, the ratio is redgced to approximately 3.4:1. If one also takes into account the enhanced performance of the more expensive material and the sub- sequent increase in service life and decrease in plant down-time, the economics of the usage of materials such as titanium becomes much more attractive and, indeed, highly competitive,

Jan 1, 1969

By A Chandra, P Guj

Only a few complex real options can be valued using closed-form equations, such as the Black and Scholes formula, because these algorithms are restrictive and prevent the construction of practical project evaluation models. Although a binomial lattice method paired with the ærisk-neutral probabilityÆ provides an easier and flexible modelling of exploration and mining projects, it has limitations when projects are complex, long-lived and influenced by the interplay of various market and private uncertainties. In order to overcome these limitations, modern decision tree software using dynamic programming capability can be used for real option valuations. This is a powerful computational tool in which the impact of various sources of uncertainties can be differentiated, so that the optimal decision path can be explicitly displayed visually. There has been significant academic controversy surrounding whether different real option (RO) valuation methods would lead to different real option values (ROV). This paper, using a realistic copper mining example, demonstrates that as long as the same degree of subjectivity and consistency are used in different real option valuation methods, they yield the same result. This conclusion is valid irrespective of whether the cash flow volatility generated by various sources of uncertainties is handled in an aggregated or in an explicit and differentiated manner. This paper compares two choices for an investor either to æbuy now and developÆ a project or to enter into a ætwo-year option to purchaseÆ after the proponents have developed it. It also shows how significantly different net after-tax operating cash flows may be generated by these different choices on the same underlying asset represented by the project. This is due to the difference in the amount and timing of the relevant capital investments affecting the depreciation and amortisation charges and as a consequence, the income tax paid. CITATION:Guj, P and Chandra, A, 2012. Real option valuation of mineral exploration/mining projects using decision trees - Differentiating market risk from private risk, in Proceedings Project Evaluation 2012 , pp 177-188 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

By P Minkkinen

"Pierre Gy showed in his early works that the results in estimating the variance of the mean value of continuous lots depends on sampling mode (random, stratified or systematic), except in the theoretical case that the measurand is randomly distributed in the lot. The experimental variance estimate calculated from samples taken from the lot is independent of sampling mode but depends on sample size and the type of the lot heterogeneity. Variography can be used to estimate the variance of the lot mean for different sampling modes.Gy also defined weighting error, which is made if a simple average is calculated from the assays of samples taken from a continuous object (eg from a process stream) where the flow rate varies with time and is correlated with the concentration of the analyte in the stream.The effect on sampling uncertainty of the three sampling modes and their interaction with the following factors in estimating the uncertainty of the mean concentration is studied using simulated lots, and lots having heterogeneity patterns similar to those of real data sets, including the effect of: the type of heterogeneity (random, grading and clustered heterogeneity patterns) increment size and number employing composite sampling weighting error. CITATION:Minkkinen, P, 2017. Dependence of the variance of lot average on the sampling mode and heterogeneity type of the lot, in Proceedings Eighth World Conference on Sampling and Blending, pp 319–330 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

May 9, 2017