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By M J. Ireland, D P. Horne, S J. Simpson

The Sinclair Nickel Project, wholly owned by Xstrata Nickel Australasia (XNA), includes an underground mine, a concentrator, a village, an all-weather airstrip and associated mine infrastructure. The operation is located 70 km north of Leonora in the prospective and historically productive eastern Goldfields region of Western Australia. Xstrata Nickel has successfully developed the Sinclair deposit into a 350 kt/a operation since its discovery in November 2005, with contained nickel metal production to date in excess of 10 600 t, of which 5500 t is from the underground operation.The narrow, continuous, medium-grade Sinclair nickel sulfide deposit accessed by the Phoenix Decline has a shallow 15¦ - 20¦ plunge that is approximately 1000 m long down dip and open at depth to the north. The flat plunge and low-grade nature of the orebody presents challenges regarding the amount of horizontal waste development that can be economically excavated, which in turn affects ventilation, egress, mine services and diamond drilling.The mineralisation is hosted between an ultra mafic hanging wall and a basalt footwall and is being mined using a bottom up, sublevel open stoping method. The stopes are retreated to a central access, filling voids in the process with waste mullock where possible and using cemented mullock fill where end exposure is required. Tight filling the flat dipping hanging wall has proved to be challenging given the angle of repose for the waste mullock fill is steeper than the angle of the hanging wall.Reconciliations of mine performance against the original feasibility study show positive changes and operational optimisations enabling Sinclair to achieve its mining targets in a safe, sustainable and economic manner. This paper discusses the mining operations associated with the first two years of the Sinclair Underground Nickel Project, providing an overview of the various issues encountered and the lessons learnt in the process.CITATION:Ireland, M J, Horne, D P and Simpson, S J, 2012. Overcoming mine design and production challenges at the Sinclair underground nickel project, in Proceedings Narrow Vein Mining 2012 , pp 37-48 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By Dawes S

Efficient roof control in colliery operation is a factor that must be maintained for· the maximum reQovery and economic extraction of the mineral. It must be carefully considered in each of the following stages in the life of a mine.1. The primary development and the first working of the mine.2. The maintenance of access roads, intake and return airways.3. The extraction of pillars.FACTORS IN ROOF CONTROLThe main objects of roof control are: The support of the roof in working places, the relief of roof pressure from the workings during pillar extraction, and in some instances the prevention of subsidence of the surface.The support of the roof during development operations and first working, and the subsequent maintenance of these is influenced by:-1. The depth of the seam below the surface.2. The thickness of the seam.3. The dip of the seam.4. The condition of the roof and floor.5. The method of extraction-mechanical or by hand.6. The method of. working-Iongwall or bord and pillar.7. The availability of material.As a general rule, the pressure exerted by the superincumbent strata may be taken as one pound per square inch for each foot of cover, and the crushing strength of coal as 1,500 to 2,000 lb. per square inch; this, of course, varies, but from these figures it may be assumed that seams below 2,000ft. in depth are liable to crush. If any part of the seam is removed, added weight is thrown onto the remaining coal. It is therefpre essential that for effective working this extra weight must be removed or supported as soon as possible.The outstanding principle in the support of mining excavations is to ensure that the supports are set as soon as possible after the natural support has been removed.Where a system of bord and pillar is applied, the early setting of supports reduces the extent to which the roof bends, thereby reducing the liability to ·tension fractures at the centre of the road.

Jan 1, 1947

By D L. Decker, G C. Miller, C Papelis

Arsenic, often associated with precious metals ore deposits, is a major contaminant released during large-scale gold mining. Because of the complex oxidation/reduction and sorption behaviour of As, prediction of the long-term mobility of As in pit lakes is uncertain. The behaviour of As in pit lakes is investigated in this paper by conducting a series of laboratory experiments where As is allowed to adsorb onto pit lakes sediments. Experiments were conducted over a range of pH with both As(III) and As(V) allowed to adsorb onto sediments collected from existing pit lakes found in the three main orebody types in Nevada, USA; porphyry copper, quartz-adularia gold, and Carlin Trend type gold deposits. Results from adsorption experiments show that As(V) and As(III) adsorption is strongly pH dependent with higher uptake at pH 5 and lower uptake at pH 9 for As(V) and higher uptake at pH 9 and lower uptake at pH 5 for As(III). This behaviour, as expected for oxyanions, has been described previously for agricultural soils, iron oxides, and Carlin Trend heap materials. Maximum adsorption of As(V) for the Carlin Trend type gold sediment was 3.0 g/kg at pH 5, 2.0 g/kg for the quartz-adularia sediment, and 0.9 g/kg for the copper porphyry sediment. Maximum adsorption of As(III) for Carlin Trend type gold sediment was 2.5 g/kg at pH 9, 2.2 g/kg for the quartz-adularia sediment, and 2.1 for the copper porphyry sediment. Adsorption isotherms are non-linear and show Freundlich isotherm behaviour. Variations in sorption between the different pit lake sediments under similar conditions can be explained by differences in the elemental composition of the sediment. Most rock forming elements from XRF analysis are similar in quantity except for Fe. The Fe content is highest in the Carlin Trend type gold deposit sediments and lowest in porphyry copper deposit sediments and is the third most abundant element in all three sediments. The Fe content of the sediments correlates well with the amount of As sorption seen in the laboratory experiments.

Jan 1, 2003

Cyanide is a significant contributor to the cost of producing gold. Any reduction in cyanide consumption that is achieved through more reliable measurement, and/or more efficient management of cyanide dosing rates, can produce a significant financial saving to the mine operation.

Jan 1, 1997

Discovery 2000 is basically about data, its collection, management, assessment and dissemination. A major focus of Discovery 2000 is the collection of new geoscientific data. However, the Department is already a major source of data on the geology and mineral resources of New South Wales. These existing data when combined with the new data, will greatly enhance the knowledge of and information on the geology and the mineral development potential of New South Wales. This paper discusses some of the existing datasets and outlines how they can be accessed. It also gives an insight into the Department's strategy for data and information technology management.

Jan 1, 1995

Rocks of all geological ages are present on the Australian continent. As a result of its geological heritage, Australia is richly endowed with mineral and energy resources. Due in part to its enormous mineral wealth, the nation is in the position of being a wealthy country surrounded by less developed countries of the Asian and Pacific region. Over many years Australia has developed and gained valuable experience in the exploration, mining and processing of a wide range of mineral and energy resources. In an interdependent world community, it is obviously in Australia's interest to cooperate and provide assistance in geoscience education and training to developing countries of the region.

Jan 1, 1986

The use of econometric models to assess the effects of a Government's policy on an industry is gaining momentum. This is particularly so for the Mineral Industry and it is important that mineral industry management understands the techniques involved in developing econometric models. Models are usually constructed outside the industry by either government departments or their consultants and used by the policy makers to investigate artificially the implementation and ramifications of new policies. This paper discusses the application of econometric models in Governmental policy determination, highlights the use of various models in Australia and gives an overview of the techniques involved using Australian examples.

Jan 1, 1982

By J Vann, C Seymour

Geology is generally treated as a æfront endÆ step in mine development. After infill drilling, the majority of resource estimation, mine-planning, development, mineral processing strategies and operational procedures are planned and implemented with little geological input, particularly in open pit operations. However, significant benefits in overall costs, cash flow, and technical risk reduction can be realised when sound geology is utilised more rigorously throughout the mining process. This under-utilisation of geology in the mining process has arisen due to a combination of factors:A lack of interest in, or knowledge of the full mining process by geologists. Few geologists fully understand where their inputs make critical impacts on downstream users. As a result of this, geologists generally do not focus their inputs towards areas of greatest value added, ie addressing issues critical for other members of the mining team. Most importantly, few geologists effectively communicate their results to the downstream users of their geology models. The results are that the potential benefits of geology, and the appropriate status of geology in the mining industry, are not fully realised. It is fundamental to realise exactly what geologists do. Geologists constrain geological processes and geometry. All geoscientific tools at the geologistsÆ disposal are geared towards one of these goals. An emphasis on geological processes is present throughout the exploration process, whereas in the resource estimation and mine development process an emphasis on geometry is required. The mining process is a web of disciplines that are attempting to optimise development of a resource to provide value to shareholders. Yet few people within these disciplines have a full appreciation of this web, and where sound geology inputs can add value through various feedback loops. Geology inputs do not end at the resource estimation stage, nor are they relegated to grade control implementation. If geologists have an appreciation of the mining process and close liaison with the other disciplines such as geostatistics, geotechnical engineering, hydrogeology, and mining engineering, they can significantly benefit project costs, timelines, and constrain technical risk by addressing their issues at the earliest possible stage. Furthermore, the mining process is not a single pass timeline, but an iterative process where the exploration, resource definition, mine planning and mining loop is continually repeated over the life of a project. Therefore, the potential inputs of geology are critical throughout the mining process. Effective communication of the impacts of geology inputs on downstream users is often lacking on mining projects. The most effective way to communicate geological results is through where it impacts most û project risk. Focussing all geology inputs and communication in terms of potential material risk allows the geologist to be more effective in contributing value to the mining process, and allows the downstream users of geology inputs to better constrain the risks associated with their aspects of the mining project. Through a program of geologists:taking an interest in the entire mining process and identifying critical areas for geology inputs to downstream users (the geologistsÆ clients); focussing geology inputs to address the potentially material issues on mining projects; and communicating their inputs to the æclientsÆ in terms of technical risk, geology will be much better integrated into the mining process. As a result, the potential benefits of geology throughout the mining process will be realised, and the status of geologists within the mining process will be elevated to a more pivotal position.

Jan 1, 2000

By N F. Glenn, S Thiruchittampalam, B P. Banerjee, S Raval

The determination of shear strength parameters for the spoil material plays a crucial role in the assessment of a dump’s stability; nevertheless, their evaluation necessitates laborious laboratory experiments. In order to address this issue, Simmons and McManus (2004) formulated a framework that serves as a foundation for categorising spoils according to their distinctive shear strength parameters based on observable and tactile characteristics. This framework, previously identified as the ‘BHP Mitsubishi Alliance Coal (BMAC) Spoil Shear Strength Framework’, is now recognised as the ‘CoalSpoil’ framework. The spoil characterisation provided by the CoalSpoil framework offers benefits but is not without limitations. The examination of these attributes in the field is a time-consuming task that demands expertise. Subjectivity arises in the spoil characterisation when attributes straddle the line between two categories, such as delineating matrix-supported and framework-supported fabric structures. To enhance consistency in the spoil characterisation process, minimising human intervention is crucial to mitigate bias, classification errors, and safety risks. This study seeks to achieve this aim by introducing image-assisted and automated methods for spoil characterisation.

Sep 1, 2024

By Gabriella Mendez

Worthy of note in Miss Bailey's paper are her comments on the attitudes of mining companies and their managers where women were employed, she says, "..another possible pitfall is reverse discrimination where in an effort to avoid being branded as having shown a person favouritism, supervisors end up treating the person in a manner much less than they deserve. This is manifested in denying an employee such things as challenging work, educational opportunities, promotions, or in the case of staff, fair merit increases." and further she says, "It has been observed that the treatment of women in non-traditional roles such as mining is different than for men in the same environment. There are people who treat women worse and some who treat them better simply because they are of the other sex." These statements may sound unjustified to today's audience, and whilst we need to credit pioneering women with having tolerated, understood and worked towards improving the mining culture, the move towards total inclusion of women in the workplace is still growing.

Jan 1, 1995

The sampling of a run-of-mine (ROM) ore with the objective of controlling the fundamental variance associated with the sampling step is a poorly understood subject. Finding the effective sampling constant by repetitive sampling to establish the variance between nominally identical subsamples of a given mass of the ore is a laborious, time-consuming and very expensive exercise. In this paper, the run-of-mine ore is modelled using three components: ore, waste, and relatively fine material which shows significant liberation of the mineral phase(s) carrying the target analyte. The expression for the sampling constant of the mixture is developed from first principles. The form of the equation provides insight into the factors that are important in controlling the magnitude of the sampling constant and hence the fundamental uncertainty associated with a given mass of sample. The controlling factors are shown to be the size distribution of the ore/waste mixture, the proportion of waste mixed with the ore and the extent of liberation and the size distribution of the liberated material in the finer fractions.

Jan 1, 2008

By Jefferson CB

Adaptive optimisation is the adjustment of operating conditions to maintain optimum process performance as the feed quality varies. This strategy has the potential to be economic- ally better than the maintenance of a constant optimum performance with a blended feed. Application of the strategy is hindered by practical difficulties and economic risks. A computer simulation of leaching processes has been used to identify ore-process systems which have the greatest potential benefits from adaptive optimisation. They are systems with low value feed materials and a broad distribution of reactivities, in pro- cesses which are sensitive to the operating variable that is being manipulated (e.g. residence time). Improvements of up to 13% in throughput and 5% in the economic operating margin can be achieved. The results are sen- sitive to the precise model which is used for the process kinetics. It seems that the kinetics of the last few per cent to react are particularly relevant. A realistic situation has been identified where a synergistic inter- action occurs in blended feeds which makes adaptive optimisation disadvantageous.

Jan 1, 1984

The ore body being worked is about one hundred feet in length by seventy feet in width. A face of about fifteen feet is stoped over the whole level at one operation, this height standing without any timber.Double lines of logs, twenty feet in length and from ten inches to one foot in thickness at the small end, are then laid longitudinally, butt to butt, and breaking joint from end to end of the ore body they are at ten feet centres from wall to wall. The starting logs are single for the first ten feet and their ends are hitched into the solid rock. These are called "miners" and are the logs which are picked up as the level underneath is worked up. The double layer gives a better chance of picking up. Logs are now laid from the centre of the ore body at right angles to the miners, the ends being hitched into the walls. A space, seven feet wide, is left open right through the centre of the ore body...

Jan 1, 1904

Milling Practices Ore is direct tipped into a gyratory crusher and crushed to minus 209mm and fed to stockpiles for the blending of grade into the mills. Secondary and tertiary crushing reduces the mill feed to minus 12mm. Mill feed is a blend of breccia and porphyry ore into two primary mills with the overflow to a regrind mill and then into the leach tanks, followed by a conventional counter current carbon in leach circuit. Underflow from the cyclones feeds back into the primary mills for additional grind. An unusual feature of the Mt Leyshon milling circuit is a desire to produce scatts. The scatt by product is the polished base rock of the Mt Leyshon Breccia clast and contains little grade. These scatts are produced because of the additional time and energy required to produce a proportionally small quantity of gold. The residence of these scatts in the mills decreases the mill feed rate. Scatts account for twenty percent of the mill feed and are screened from the discharge of the primary mills.

Jan 1, 1990

Bougainville Copper Limited (BCL) ships about 600,000 dry tonnes of copper concentrate per annum to Japan, Germany and Spain, with some spot sales to other countries. Concentrate sales value for 1984 was 335 million US$, representing almost half of PNG exports. Contained metal determination is based on physical and chemical measurements on representative samples. The entire procedure is subject to statistical uncertainties and possible systematic errors; losses as high as several percent of contained copper or gold are common and frequently are regarded as unavoidable. In this context, the function of the chemical laboratory is to identify and eliminate such errors and recommend correct technical procedures for possible inclusion in sales contracts. BCL's marketing management has encouraged this approach and the close buyer versus seller agreement is beneficial for all parties involved. BCL participates in the respective technical committees of the Standards Association of Australia (SAA) and the International Standards Organisation (ISO). Standard methods for sampling and analysis of copper, lead and zinc ores and concentrates are in course of preparation, some being due for publication shortly.

Jan 1, 1986

By T Smith

The evaluation of a new mineral resource and its economic viability is critically dependant on the quality of the assay data as it is this data that defines the grade of the resource. However, all too often the procedures of sampling and chemical analyses used to generate such data are neglected or given little consideration until final modelling and evaluation are under way. This approach frequently requires large reassay and/or re-sampling programs to be undertaken to validate or to improve the integrity of the data base. This paper outlines a step by step approach to ensure quality data is achieved and then maintained throughout the entire exploration and resource development program. This involves the use of correct field sampling methods, assay methods designed to give the required levels of accuracy and precision and quality procedures in place to monitor the effectiveness of the overall process. Thorough documentation is an overriding and necessary part of the entire process. Practical examples are given to demonstrate the use and value of these methods.

Jan 1, 1998

A good blending system is one that ensures that a plant can cope with the amount of grade variation that it will encounter. Prediction of amounts of variation that will be encountered on time or tonnage scales that are important should be regarded as an essential part of the planning of mines and plants. In some cases, the natural amount of grade variation when ore is mined and handled in the cheapest way will be acceptable. In other cases, it is necessary to understand the effects that various ore-handling processes have on amounts of grade variation at various scales and to design a blending system with considerable care. Blending tends to matter more when plants are sensitive to many aspects of grade. It can be very difficult to find the best compromise between capital cost and the amount of grade variation. In these cases it is important that ore blending options be considered carefully as part of the planning of mines and plants. Failure to make plans that consider likely amounts of variation can be very expensive.

Mar 1, 2010

X-ray analysis of polycrystalline powder samples has grown beyond its roots in the world of laboratory research and is now regarded as one of the most powerful industrial process-control tools in the field of building materials. This is the key to characterise the element and crystalline phase composition of the material. This is due largely to the development of industrial X-ray analytical systems such as PANalyticalÆs twin solution, which has transformed the advanced analytical techniques born in the laboratory into a robust, workmanlike and easy-to-use tool for todayÆs heavy industries. The increasing use of alternative fuels makes the Bogue method less reliable. Therefore, the real phase quantification by the Rietveld method is the only choice. Additional fine-tuning of the Rietveld method by using alternative methods guarantees the most accurate quantitative results. Moreover, the recent development of ultra high-speed X-ray detectors allows for æon the flyÆ quantitative X-ray diffraction analysis and a truly interactive process and quality control.

Jan 1, 2008

By Peres EC

The flotability of monazite, zircon and rutile in the presence of sodium oleate, potassium octyl hydroxamate and a commercial hydroxamate was investigated through microflotation tests in a modified Hallimond tube. Zeta potential determinations in the absence/presence of collectors were performed in a microelectrophoretical cell. The microflotation testwork showed that, in general, the flotability characteristics of all three minerals are very similar. Commercial hydroxamate is, by far, a stronger collector than the pure potassium octyl hydroxamate. Electrokinetic studies indicated that the adsorption of collectors shifts the isoelectric point (IEP) of the minerals towards lower pH values. These collectors also are capable of changing the zeta potential values to more negative figures in the pH region above the isoelectric point. An increase of the conditioning temperature, generally, enhances the floatability of the three minerals. A depressant is required in order that selective flotation is feasible in the system monazite-zircon-ruffle. Sodium metasilicate is an efficient depressant for zircon and rutile and affects only slightly the flotability of Monazite.

Jan 1, 1993

By Sterns UJ, Weller KR

Grinding to sizes less than 80 per cent passing 20 ¦m in both primary and regrind circuits is becoming increasingly important in processing metalliferous ores, as many of the remaining orebodies are very fine-grained and refractory. The process of very fine grinding, however, is expensive, and neither the performance nor the design criteria are well understood. This paper presents some findings from a collaborative research program, one of the objectives of which has been to better understand and improve the performance of very fine grinding circuits. Data from surveys of an industrial tower mill grinding circuit are reviewed and analysed using the population balance models of the CS]RO and 7KMRC. The performance of both models with regard to changes in feed size distribution, ball load and feedrate is assessed using these data. From comparisons between pilot and full scale tower mill operation a prototype scaling methodology is also presented which shows promise in allowing the models to be used to predict the effect of changes in mill Design.

Jan 1, 1993