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By J Sibbel, K Goh

A key issue facing mine managers in remote locations in Australia and overseas is that of managing a fly-in, fly-out (FIFO) workforce. Current Australian research (Sibbel, in prep) indicates that FIFO employees and their families do not differ from the general population in terms of their overall mental health and the well-being of their family relationships. However, they do face unique issues/pressures associated with the lifestyle, the impacts of which are dependent on the policies and practices of the company as well as individual coping and support mechanisms. Successful management of a FIFO site and its employees therefore requires specialist knowledge and skills beyond those of a solely residential operation. The well-being of the FIFO workforce depends on both site and individual employee characteristics, and has implications for productivity and turnover, as well as safety and health. In addition, although FIFO separates individuals and their families in time and space, the interaction between work and home must be acknowledged and taken into account. Drawing on findings from recent Australian and international FIFO research (eg Annear, Poot and Kingston, 2006; Beach, Brereton and Cliff, 2003; Brereton et al, 2006; Gallegos, 2006; Keown, 2005; Parkes, Carnell and Farmer, 2005; Sibbel, 2001, 2004, in prep; Shrimpton and Storey, 1996; Storey, 2001; Watts, 2004) this paper discusses key understandings of both the positive and negative impacts of FIFO employment on employees and their families, and provides practical management strategies as an aid to the development of best practice. Individual impacts including fatigue and loneliness, as well as family issues such as communication, continually changing roles and responsibilities and the impacts of regular parent absence are key areas which can be ameliorated by appropriate management understanding and action. A flexible framework approach is presented that is suitable for a diversity of operations, including principal and contractor workforces of different sized operations.

Jan 1, 2006

By N Clarke, R Dineen, W Jones

The Mt Lyell copper mine in western Tasmania has discharged acid drainage (AD) into the Queen and King Rivers and Macquarie Harbour for over a century. Presently, dissolved copper loads of about 1000 tonnes per annum and dissolved aluminium loads of >2000 tonnes per annum are contained in the AD, which is derived from underground workings (~60 per cent) and historic waste rock dumps (~40 per cent). Flows vary from about 100 L/s during dry periods, to >400 L/s during the wet winter. The site is presently operated by Copper Mines of Tasmania (CMT) who are not responsible for the acid drainage generated from the mine site. Although western Tasmania is famous for its mining history, tourism and aquaculture have emerged as the new industries on the West Coast, with a major tourism railway (the Abt) recently opened along the banks of the Queen and King Rivers. The emergence of these industries in a æclean greenÆ Tasmania has resulted in a strong community and government push to remediate the acid drainage. Remediation investigations and efforts at Mt Lyell were initiated by the Department of Primary Industries, Water and Environment (DPIWE), previously known as DELM, in 1995, and have included the quantification of environmental impacts arising from the AD, and the investigation and costing of potential remediation options. A primary focus of the work has been to identify cost-neutral options which recover metals from the AD in a saleable form to help defray on going treatment costs. This paper summarises these activities in generally a chronological order, highlighting findings of the program that are potentially applicable to other acid drainage sites.

Jan 1, 2003

The prime objective of geometallurgy is to improve the profitability of mines through the use of spatial models of rock properties that have a significant impact on value. Although a key property is the grade of the component of interest, because it directly influences the revenue from saleable material, increasingly attention is being focused on other attributes. These 'non-grade' variables may have a less direct, but equally profound impact on value, either by reducing potential revenue (eg lowering recovery, deleterious elements, etc) or increasing mining or treatment costs (eg comminution, grindability, throughput, reagent use, etc). Collectively, these variables have been described as 'geometallurgical'. There are three main areas of activity required to realise the value of geometallurgy: 1. acquisition of appropriate data through sampling and measurement, 2. building spatial models of geometallurgical variables, and 3. using these models to optimise value. Each of these is built on the foundation of the preceding step. In building reliable spatial models, it is critical that the amount of error introduced to data by the sampling and measurement processes is understood and quantified, in order that the inherent variability of the component of interest can also be properly understood. Management of the quality of grade variables is now applied (with different levels of diligence and success) across nearly all sectors of the mining industry, not least because of the necessity to adhere to Codes of practice (eg JORC, 2004). The necessity for quality management and at least the broad framework of what to do in practice is reasonably understood by many relevant professionals. There are also a number of tools, including software products, statistical analyses and presentation formats, available for those managing grade data. It is also abundantly clear, that in many cases people have little understanding of why they are doing particular quality control activities, or how to sensibly interpret the results. The same is not true for many geometallurgical variables. In almost all instances the authors have seen, the magnitude of sampling and analytical/measurement error variance embedded in geometallurgical test data is untested and unknown. This is partly because until relatively recently, metallurgical data has mainly been collected for the purpose of process and mill design, with few, expensive tests carried out on 'average' samples of the orebody. Increasingly however, there is a move towards collection of much larger data sets from spatially distributed sampling, and thus a growing necessity to understand the errors inherent in both sampling and analysis of these types of variables, and how to manage them. In order to understand how the quality management practices applied to grade variables can be extended to geometallurgical variables, it is essential to understand the theoretical foundation that supports these practices. This requires an analysis of the concepts that underpin the 'principles of additivity' (Matheron, 1963), the 'theory of sampling' (Gy, 1982, Pitard, 1993), and 'statistical process control' (Shewhart, 1930). Relevant concepts are then integrated to form a foundation to develop methods to improve the quality management of geometallurgical variables. Application of this framework will significantly increase the integrity of geometallurgical data, the reliability of geometallurgical models and ultimately the value derived from implementing geometallurgy. This is an ABSTRACT ONLY no paper was prepared for this presentation.

Mar 1, 2010

By G Hayes

Ore from the Browns deposit near Batchelor, in the Northern Territory of Australia, is a fine-grained polymetallic sulfide ore hosted in graphitic black shale. Minerals of economic significance are seigenite (Co,Ni)4S3, Galena (PbS) and Chalcopyrite (CuFeS2) with minor Sphalerite (ZnS). Gangue minerals include quartz, carbon and K-feldspar. The grain size is fine, with a significant amount of the seigenite present as Early flotation work determined that a grind size of around 20 microns was required to achieve clean sulfide concentrates. This work recommended oil agglomeration flotation, in which small sulfide minerals were collected, then loosely agglomerated with oil ahead of flotation into a heavily mineralised froth. In the 400 kg/hr prototype plant this froth proved unmanageable. A conventional flotation circuit after grinding to a P80 of 24 microns and using very low flotation pulp densities resulted in an 86 per cent cobalt recovery.The paper analyses further laboratory work which has increased cobalt recovery to 91 per cent by grinding to û250 microns ahead of flash flotation. The real cobalt recovery breakthrough comes from flash flotation of the whole mill discharge rather than the more usual flash flotation of cyclone underflow. Flash flotation tailings are ground to û38 microns and are floated under normal flotation conditions with only the scavenger concentrates being reground to 20 microns.A one tonne per hour prototyping campaign is scheduled to demonstrate the robustness of this circuit.

Jan 1, 2002

By D A. Manhire, R M. Flores

The commercial develop of coalbed methane from the Powder River Basin has demonstrated that low-rank coals can be a viable source of gas. Currently over 20 000 coalbed methane wells exist in the Powder River and it is predicted that there will be 50 000 wells by 2010. What makes the Powder River Basin successful is the thickness of the coal (in excess of 30m) as well as the low ash content (

Jan 1, 2002

By R Garzon

For resources projects with healthy net present value (NPV) and low cash flow volatility, conventional discounted cash flow (DCF) analysis will continue to provide the dominant investment decision-making criteria. However, DCF analysis can be biased because it often applies a single risk-adjusted discount rate (RADR) to compare the value of projects with different risk characteristics. Many of the difficulties with DCF modelling arise from analystsÆ inability to determine appropriate risk discounts and to estimate expected spot prices inputs for the commodities produced over the life of the project. Modern asset pricing (MAP) is a very valuable complement to DCF analysis in addressing some of these issues. Most papers dealing with MAP, however, while academically rigorous, tend not to be explicit in terms of practical application of this methodology in routine project evaluation. This paper has the objective of reviewing the MAP methodology and of demystifying its complexity, by providing a simple but realistic step-by-step evaluation of a mining project, comparing its DCF and MAP NPV values. The paper concludes that MAP provides a minimum, risk-adjusted æfloorÆ value, thus representing a valuable complement to any DCF valuation.

Jan 1, 2007

Grinding and Beneficiation Characteristics of a Low-Grade Haematite Ore

Sep 13, 2010

By R G. Barker

This paper reviews the annual status of the New Zealand mining industry (metallic minerals and coal) including key aspects such as mineral production, mineral exploration expenditure, commodity price trends, key industry players, market activity and other significant commercial factors.   Strong commodity prices during 2006 have been underpinned by a number of key factors including US dollar weakness and emerging market demand, particularly from countries such as China and India. In real terms commodity prices have recovered significantly since 2002 and are currently at 20-year highs.   New Zealand exploration spending on metallic minerals (predominantly gold) is at a 15 year high driven by rising global commodity prices. New Zealand gold production in 2006 was about 340,000 oz and is expected to grow in 2007 as new mines at Frasers and Globe-Progress (Oceania Gold) and Favona (Newmont) come on stream. Gold production broadly lags 10 years behind exploration spending and exploration activity over the last five years remains well below that seen in the early 1980Æs. Expenditure on coal exploration shows a similar trend with strong growth from a low base over the last five years, reaching over $11 M in 2006. Total coal production in 2006 was 5.9 Mt, an increase of 10% on 2005 with imports from Indonesia adding a further $1.1 Mt.   Newmont and Oceana Gold are by far the largest public gold mining companies operating in New Zealand, although only Oceana Gold maintains a presence on the local stock exchange. Other metals explorers with New Zealand projects include a range of public-listed Juniors (market capitalisation less than NZ$50m) domiciled largely in New Zealand, Australia and/or Canada. Capital-raising on public markets directed towards New Zealand exploration is estimated at around NZ$12 M for 2006, the bulk of this coming via Glass EarthÆs NZ$10 M IPO on the NZAX in October.   The New Zealand Coal sector is dominated by the state-owned enterprise Solid Energy with around 80% market share by production. Other domestic coal competition remains limited, and includes the L&M Group, Pike River Coal, Eastern Corporation, and New Vale (acquired by Solid Energy in 2007). Pricing parity comes mainly from imported coal and global thermal coal prices have remained strong during 2006 at around US$45-55/t, driven by continued expansion in Chinese demand. Coking coal prices have eased 16% since 2005 to around US$98/t in 2007.   Although recent increases in exploration spending suggest a renaissance in the New Zealand minerals sector, long-run trends indicate that we have simply rebounded from a low base over the last five years and much work is still to be done to stimulate further growth in the mining industry to maintain minerals production at current levels. Key industry challenges include marketing exploration opportunities to local and overseas investors, building a critical mass of NZX-listed explorers and providing an internationally competitive environment to attract further capital and expertise.

Jan 1, 2007

The structure and tectonic setting has had a strong influence on gold mineralisation at the Porgera gold deposit. Here, the structural controls on the mineralisation at Porgera are discussed and placed in a regional tectonic context. The Porgera gold deposit is related to the emplacement of the Porgera Intrusive Complex. Prior to intrusive emplacement at Porgera,Papua New Guinea was affected by a major fold and thrust episode which occurred in response to arc-continent collision in the Late Miocene. After crustal shortening the region experienced a relaxation of compression which is expressed in the deformation accompanying mineralisation at Porgera. The first stage of mineralisation (stage I) is hosted by extension fractures, and is spatially associated with exposed intrusive stocks. A later episode of mineralisation (stage II) is hosted by the faults and fractures of the Roamane Fault Zone, which was active as a dip-slip normal fault during stage II mineralisation. Therefore a change in the tectonic environment from shortening to extensional tectonics can be seen at Porgera before and during mineralisation. Rapid fault-slip during stage II mineralisation may have aided high-grade gold mineralisation by subjecting hydrothermal fluids to changes in pressure, temperature, fluid-fluid and fluid-rock interaction. Uplift to form the highlands of Papua New Guinea occurred after mineralisation and was largely complete by 4.0 Ma.

Jan 1, 1995

In a modern economy there is a compelling case why governments should not own property rights to mineral deposits. Assuming they do, however, governments will use these constitutional rights to raise revenue. They have two basic instruments to achieve this; a royalty charge on price or a rent tax on income/profits. On the one hand, a royalty charge creates a 'deadweight loss' to society by increasing cut-off grades and decreasing the life-of-mine. They are also regressive. However, they are easy to administer. On the other hand, a rent tax avoids the problem of 'deadweight loss'; it does not impact on the life-of-mine because the tax structure is neutral. But, they are difficult to administer correctly, particularly in the determination of rents and the definition of mining per se. If rents are incorrectly determined capital markets are distorted. And, if mining activities are incorrectly defined, downstream activities could be adversely affected.

Jun 1, 2010

Management of Mining Wastes in European Union and Developments in Turkey

Sep 13, 2010

I report results of over 850 microprobe analyses of sulfides, sulfosalts and electrum from the Favona adularia-sericite epithermal deposit of the Waihi district in the southern Hauraki Goldfield of New Zealand. Pyrite and marcasite from altered wall rocks that enclose the veins are stoichiometric, with compositions of FeS2, and no significant trace elements. In contrast, pyrite in veins commonly contains appreciable As (up to 3.2 wt per cent), and locally contains several tenths of a percent of Cu, Zn, Co, Ag and Sb. Vein pyrite may contain up to 0.22 per cent Au, but Au contents do not show a positive correlation with As. Limited electrum data indicate that it ranges from Ag0.47 Au0.53 to Ag0.54Au0.41Cu0.01Zn0.04. Chalcopyrite is stoichiometric CuFeS2, and most galena is PbS, but some galena contains up to 4.4 wt per cent Se, which substitutes for S in its lattice. The galena is not argentiferous; the highest Ag content is 0.45 wt per cent Ag. Sphalerite averages 4 mol per cent FeS, but ranges up to 15 mol per cent. Tetrahedrites [(Cu,Ag)10(Zn,Fe)2(As,Sb)4S13] show variable substitution, but most are Cu- Zn- and Sb-rich. Veins also contain aguilarite (Ag4SeS), stromeyerite (CuAgS), naumannite (Ag2Se), and mckinstryite [(Ag,Cu)2S].

Jan 1, 2004

Study on Oil Agglomeration Flotation for Deinking

Sep 13, 2010

By A Bouazza, J Kodikara

In this study, 23 samples of leached ash (LA) were collected from an ash pond at Loy Yang Power Station and geotechnically characterised. The samples were collected at various depths and locations within the ash pond on two separate occasions in order to account for the full variability. The LA within the ash pond at Loy Yang Power Station (LYPS) was found to vary in texture from silt to sand, depending on the location from where the sample was collected. Samples collected near the ash pond inlet discharge point, for instance, contained more than 50 per cent sand sized particles and were subsequently classified under the Unified Soil Classification System (USCS) as silty sand (SM). Further downstream of the inlet discharge, the LA became progressively finer and was classified accordingly as elastic silt (MH) when the sand content became less than 50 per cent. Basic geotechnical testing revealed that the LA from Loy Yang Power Station was generally acceptable as a landfill cover material. The permeability of LA, however, was generally too high for prescriptive covers, (ie resistive covers that generally rely on the impervious nature of the material to control percolation). Alternative covers, generally rely on the store/release function of a capillary or monolithic barrier to prevent percolation into the landfill. Subsequently, a material that can maintain a high water storage capacity while at the same time, readily allow infiltration and evapotranspiration is required for an alternative cover. Sandy silt and silty sand are optimal soils for alternative covers, as they do not yield water to gravity forces, but do give up most of the water in their pores when subjected to high-matric suction (Kavazanjian, 2001). The effectiveness of alternative covers is ultimately assessed using computer models, such as UNSAT-H and HYDRUS-2D, to rigorously perform water balance calculations. Prior to using a computer model to determine the highest possible percolation in the worst climatic conditions, it is necessary to select the most appropriate materials. This paper suggests a method to screen available materials for use as an alternative cover material on the basis of the soil water characteristic curve (SWCC).

Jan 1, 2003

The use of scrapers in mining and earthmoving operations is not new, in fact they are one of the earliest methods of bulk earthmoving. A single machine which can load, haul, and dump material with a minimum of ancilliary support is a highly productive and cost-efficient method of earthmoving. In recent times scrapers have been unpopular due to perceived problems and operational limitations, but the last couple of years have seen a resurgence in the use of scrapers in the Bowen Basin as a primary prestripping tool. The main operational limitation of scrapers is the economic operating range. maximum productivity and lowest cost per bcm is achieved on short leads, as the lead distance increases the cost per bcm quickly reaches and then overtakes that of an truck-excavator fleet. The geometry of a ætraditionalÆ coal mine does not readily allow short leads for prestrip fleets due to the nature of dragline stripping operations. The strip arrangement means that material has to be taken around the end of the pit, meaning a longer haul distance than the actual point-to-point distance between load and dump. This can be alleviated by using pit bridges, however these can cause spoil problems for draglines if not properly planned and have been avoided by many mines. Due to the economic haul distance limitation of scrapers, truck-excavator fleets have become the normal method utilised. Currently more geologically complex mines are opening up, which do not allow traditional down-dip strip mining to occur. Cross-dip mining methods allow for short leads between prestrip loading and dumping areas, hence scrapers and bulk doze are realistic alternatives to a truck-excavator fleet in the prestrip environment. Keeping the lead distance to a minimum a fleet of 657Æs can move material at a very low cost. The other main operational limitation of scrapers is the type of material that can be economically excavated. Hard material can lead to damage to the bowl, free-flowing sand will not readily stay in the bowl leading to reduced load factors. Ripping the material with a dozer prior to excavating can lead to improved loading time, and greatly reduced GET consumption. When considering scrapers for prestrip operations a number of things must be considered: is the lead distance within the economic haul distance? should twin power (push-pull) or single power (dozer pushed) scrapers be used? do I need to rip, what should I rip with? what ancilliary support is required? is there another system already available on-site which is currently under utilised? This paper considers the parameters under which large twin power scrapers are the most effective way of undertaking prestrip operations.

Jan 1, 2003

By Hori M, Komatsu T

In Japan, a small-diameter tunnel boring machine (TBM) of diameter 2.6 m applicable to a wide range of geology from hard rock to soft strata was developed with the purpose of reducing construction costs of headrace tunnels for small hydroelectric power stations. And in 1983, a demonstration test was carried out in the No. 1 headrace tunnel work of Hayakido Hydroelectric Power Station. The principal achievements in executing work are the following: (1) Although this TBM was a demonstration test unit, excavation advances averaged more than 200 m/month and exceeded the average 150 m/month with a conventional method. (2) According to PS velocity surveys after tunnel excavation the zone of loosening due to the TBM method was small enough to be ignored and was approximately one-half compared with conventional methods in rock of the same evaluation.

Jan 1, 1987

Temperature Sensitive Polymers as Efficient and Selective Flotation Collectors

Sep 13, 2010

CONTENTSThe significance of values givenINTRODUCTIONTHE ORE1. DATA SECURED FROM THE MILLING PLANT AS OPERATING BETWEEN 1938 AND 1942(a) Mill Recoveries(b) Mill Flow Sheet(c) Scheelite-Garnet Association(d) Detailed Examination of Mill Performance during 1942Crushing UnitsCoarse Rolls DischargeFine Rolls DischargeFeed to Huntington MillsFinal Ground ProductProduction of -200-mesh Scheelite SlimeSummary of Information on Crushing and Grinding Circuit(e) Detailed Examination of Mill Performance During 1942Concentrating UnitsLocation and Nature of Scheelite LossesSize Distribution of Scheelite LossesDistributor Spigot ProductsSummary of Information on Concentration Circuit(f) Detailed Examination of Mill Performance During 1942 Gravity Plant Feed2. EXAMINATION OF MINE SAMPLES TAKEN DURING 1942(a) Introduction(b) Nature of the Ore(c) Sampling of Mill Feed(d) Testing Technique(e) Minus 1/8-inch Ores-Naturally Broken Fractions(f) Recoveries from Plus 1/8-inch Fractions-Crushed to Minus 1/8-lnch(g) Probable Recoveries Obtainable from Weathered Ores140 Contour120 Contour90 Contour(h) Examination of an Ore Sample from the 90-foot Adit(i) Run-of-Mine Ore(j) Evidence of Maximum Sizes of Scheelfte Present in Run-of- Mine Ore(k) Summary of Information on Liberation and Recovery from the Ores as Mined in 1942 and from the Mill Samples

Jan 1, 1944

The Effect of Non-Toxic Depressants in Chalcopyrite Flotation

Sep 13, 2010

By W J. Cowie

Several years of operating experience of over 100 gold recovery operations on the West Coast has provided a database from which the basic operating costs of these types of operations can be characterised. Using figures generated from the averaging of plant operating costs throughout the region and financial modelling using Lotus spreadsheets has been developed to analyse both existing and proposed developments. This type of modelling has several uses: 1. Identification of the impact on profitability of changes in management practices, finance costs, operating costs and revenue streams. 2. Project evaluation and planning. 3. Profitability projections for development financing. 4. Troubleshooting with existing operations. 5. Valuation of existing operations and properties.

Jan 1, 1987