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The Black Star lead and zinc ore-bodies, situated in the western zone of mineralisation at Mount Isa occupy an area 2000 ft. long with varying widths from 100 ft. to 300 ft. The strike is N5°W, and the average dip 60° West.To test at depth the potentialities of this area, an extensive diamond drilling campaign was commenced on 16th October 1927. It was continued, with from one to six machines working, until the end of 1931. During this period, 26 inclined holes, with an average depth of 1224 ft, and a total footage of 31,828 ft. were completed. A vertical hole, 2452 ft. deep, for comparative purposes, has been omitted.These drilling operations came directly under the charge of G J Gray, General Superintendent of Mount Isa Mines, and, in the early stages were supervised by E. D. McDermott, of the Mining Trust, London. The foremen, who were in charge of various sections of the drilling operations, were: H Vale, F Bray, J Winston and A A Sanstedt.

Jan 1, 1932

By T Goswami, G Brent

In response to concerns over greenhouse gas (GHG) emissions and an imposed cost in some jurisdictions, many mining houses have committed to reductions in their GHG emissions. However, mining faces particular challenges in this regard, notably from increasing strip ratios. Furthermore, mining activity around the globe is not expected to decrease in the foreseeable future as mineral demand is driven up by the aspirations of rapidly-developing nations. Novel approaches will thus be needed if any reductions in energy consumption and GHG emissions of mining are to be achieved.This paper presents some directions for the mining industry to pursue in reducing their GHG impact, focusing on the difference that blasting methods can make. Importantly, large productivity and revenue gains can also be realised from these methods.Key directions considered here include optimising resource recovery and quality through:reducing coal damage and loss from throw blastingrecovering thin coal seamsproducing cleaner coal with less dilution.Blast design can also significantly improve the productivity of surface mining by:improving muck pile shapingimproving mine equipment productivityimproving scheduling.We show how a particular blasting method can eliminate coal loss in overburden throw blasting and can lead to large increases in coalmine profitability. Thin seams that were previously wasted can also be recovered with this method. Furthermore, the method has been implemented to combine several separate drill and blast cycles into a single cycle, leading to productivity gains.An illustrative example is given to show how increased coal recovery can increase revenues and more than offset any potential GHG emissions liabilities. Overall mine energy and GHG emission intensities can thus be reduced.CITATION:Goswami, T and Brent, G, 2015. Blasting approaches to increase mine productivity and reduce greenhouse gas emissions in surface coal mining, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 635–644 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

Consolidated Rutile Limited (CRL) was one of the best performing mining stocks of the turbulent 1980s, having a very high payout of franked dividends. In contrast to some other mining groups, it was not highly involved in the speculative lead-up to the 1987 sharemarket crash. Its base was firmly laid through a succession of decisions that were taken in the period 1982-1985. These decisions and the rationale behind them are outlined in this paper. CRL began the 1980s in a highly favourable position. It had successfully pioneered the transition to high-throughput mining of the high dunes on North Stradbroke Island (NSI), commissioning its 2100 tph cutter suction dredge at the Bayside reserves in 1978 at the time of rising prices, such that it was able to pay off its modest bank loan within 18 months. The June 1980 results showed a record after-tax profit of $5.6M, from total assets fo $26.5M and sales tonnages of rutile and zircon of around 50,000 tonnes each.

Jan 1, 1991

By M Steinberg, M Amarant

Upstream Classifier are well-known in the iron ore industry for at least 15 years. At present, more than 60 units are in operation in Western Australia. The advantage of this technology is their capability to produce three products with one equipment – iron ore concentrate, iron ore middlings for further processing and slimes (tailings). The principal of this beneficiation process – upstream classification and upstream separation – will always remain. However, the optimisation of the classification and separation efficiency of the equipment itself is a continuous process driven by enhanced automation and instrumentation, design changes and the use of upstream and downstream information and requirements. Besides efficiency, the safety, maintenance and replacement conditions are very important subjects for the operation of an iron ore mine. The aim of this paper is to present a new allflux® upstream classifier design, which has been developed together with several iron ore producer from Western Australia. The new design benefits from its sustainability approach by dividing the entire equipment into small reusable parts. As a result, maintenance is minor, replacement much faster, lifetime much longer and costs much lower. Furthermore, it demonstrates new features to prevent hazardous working conditions such as confined space as well as new fixing devices to speed up the replacement of certain items and parts.

Sep 18, 2023

By Huleatt M, Perkin D, McLeod I, Mock C, Pratt R, Gourlay A, Timoney E, Knight N, Ward J

Generally speaking, Australia's reserves of its more important minerals (in terms of export earnings) are adequate to sustain forecast rates of production to the year 2000. The rate of forecast production increases of these commodities (aluminium - whether as bauxite, alumina or metal, black coal, iron ore and ferro-alloy minerals, base metals, tin, uranium, and mineral sands) reflects a well- ordered and sustained growth phase of Australia's mineral industry.

Jan 1, 1981

By M I. Pownceby, N A. S Webster, A J. Studer, I C. Madsen, J A. Kimpton, M J. Fisher-White, L Lu

In situ synchrotron X-ray and in situ neutron diffraction-based experimentation have been implemented to characterise the formation of the complex calcium ferrite iron ore sinter bonding phases silico-ferrite of calcium and aluminium (SFCA) and SFCA-I. Experiments were carried out using fine-grained (<20 ¦m) sinter mixtures containing ~77 wt per cent Fe2O3, 14 wt per cent CaO, 3.5 wt per cent SiO2 and 5 wt per cent Al2O3, with diffraction data collected during heating until 1300 - 1350¦C, which was enough to ensure complete melting of the SFCA phases. In the case of the in situ synchrotron experimentation, results showed that altering the nature of the starting sinter mixture (ie substitution of goethite for hematite; substitution of an amorphous Al2O3-based mineral for gibbsite) did not have a significant effect on the thermal stability range of the SFCA phases. It did, however, have a profound effect on the formation and rate of consumption of the calcium-rich ferrite phases C2F and CF, and on the formation mechanisms of SFCA and SFCA-I. The in situ neutron diffraction experimentation is the first described in the context of iron ore sintering, and the observation of both SFCA-I and SFCA formation in the in situ diffraction data represents the first step in achieving the goal of charactering iron ore sinter phase formation in large volumes of industrial sinter starting materials with a wide range of particle sizes (up to 6.3 mm).CITATION:Webster, N A S, Pownceby, M I, Madsen, I C, Studer, A J, Lu, L, Manuel, J R, Kimpton, J A and Fisher-White, M J, 2013. In situ x-ray and neutron diffraction studies of silico-ferrite of calcium and aluminium iron ore sinter phase formation, in Proceedings Iron Ore 2013 , pp 487-494 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By A Gerdes, H BrStz, E GSbler, D Davis, F Henjes-Kunst, S Dewaele, T Graupner, T Oberthnr, M Sitnikova

Following the United Nations initiative to fingerprint the origin of conflict materials, the German Federal Ministry for Economic Cooperation and Development has decided to fund a pilot study on coltan ores. Since 2006, our working group has been investigating columbite- tantalite (coltan) mineralisation, especially in Africa, also within the wider framework of establishing certified trade chains. More than 300 samples were obtained from the worldÆs major coltan producing areas. Special attention is, however, directed to samples and concentrates from Ta-Nb-Sn provinces in Africa: Democratic Republic of the Congo, Rwanda, Mozambique, Ethiopia and Namibia. Using state of the art analytical tools, we investigate mineralogical and chemical parameters obtained from columbite-tantalite ores and concentrates in order to distinguish between ore provinces, likely even down to the deposit scale. Methods employed include fully automated electron microscopy (mineral liberation analysis), electron microprobe analysis (major and minor elements), laser ablation plasma-source mass spectrometry (trace elements and U-Pb dating), X-ray fluorescence spectroscopy (bulk major and trace elements), X-ray diffraction analysis (mineralogy and structure) and thermal-ionisation mass-spectrometry (U-Pb dating). Major and trace element concentration patterns, mineral assemblages in the ore concentrates, and zoning characteristics in the different pegmatites from Africa distinctly differ from each other. Furthermore, the following age populations are evident:Archaean (>2.6 Ga);Palaeoproterozoic (1.9 - 2.1 Ga);early Neoproterozoic (æKibaranÆ; 0.98 - 0.93 Ga); andlate Neoproterozoic to early Palaeozoic (ca 0.5 Ga). Currently, we focus on the resolution of the fingerprinting system from region via ore province down to deposit scale. Our preliminary analytical results indicate that a certification scheme including fingerprinting of sources of coltan ores is feasible.

Jan 1, 2008

Adsorption Behaviours of Humic Substances onto Iron Ore Particle Surface Humic substances extracted from lignite mainly consist of fulvic acids (FA) and humic acids (HA), which have been successfully used as good composite binders for iron ore pellets in laboratory tests and industrial production. However, there exists a general lack of understanding of the interaction between humic substances and iron ore particles surfaces. In this research, by means of zeta potential measurements, Fourier Transform Infrared (FTIR) spectrum, colorimetric method and Environmental Scanning Electron Micrograph (ESEM) imaging, the adsorption behaviours of FA and HA onto the surfaces of iron ore particles are investigated. The zeta potential results indicate that adsorption of FA on the iron ore particles can be characterised by specific and electrostatic interactions, while adsorption of HA is by electrostatic and chemical adsorption interactions. FTIR spectrum results show that adsorption force of FA on the iron ore particle surfaces is stronger than that of HA. From results of colorimetric method, compared with HA, adsorption amount and adsorption rate of FA is more and faster, respectively. FA molecule presents on the surface of magnetite in the shape of an araneose network structure according to the ESEM images, while HA molecule appears on the surface of magnetite in the form of small flocs or microclusters. Humic substances are effective to iron ore pelletisation. Comparsion of agglomeration results show that the different mechanisms of adsorption result in varied agglomeration behaviours. Theses findings above would be beneficial to the implications of composite binder for agglomeration.  

Sep 13, 2010

By D J. Williams

The majority of surface tailings storage facilities continue to employ sub-aerial tailings slurry deposition. Surface TSFs are typically sized and operated in a way to minimise the initial capital cost of the facility, driven largely by the net present value approach to accounting. This generally leads to too small a storage, too fast a rate of rise of the tailings, and difficulties in managing supernatant water. In turn, this results in wet and soft tailings deposits of high moisture content and low density, and the need for frequent and costly tailings dam raises. Further, such tailings deposits often do not facilitate closure and rehabilitation of the facility. Globally, there are on average over two failures annually of such tailings dams, resulting in loss of life, damage to infrastructure and environmental impact downstream, and the loss of company shareholder value and reputation. Recent high profile tailings dam failures are threatening the mining industry’s financial and social licence to operate.Among the physical processes that tailings undergo on sub-aerial deposition are beaching, hydraulic sorting down the beach according to particle size and specific gravity, settling, consolidation, and desiccation on exposure to the sun and wind. Beaching and hydraulic sorting have proved difficult to test at laboratory scale and difficult to model, and are best assessed in the field. Settling, consolidation and desiccation may be assessed at laboratory scale, but to date there has been an absence of tests to form the basis for the design and management of tailings deposition, and ultimate closure and rehabilitation. The paper describes recent advances in tailings testing methods, including a purpose-built slurry consolidometer that tests the settling and consolidation of tailings from a slurry consistency, simulating increasing tailings depth to about 50 m; and a purpose-built instrumented column that tests the settling, self-weight consolidation and desiccation of a surface layer of tailings, also from a slurry consistency. Selected test results from these two apparatus are presented in the paper, together with brief descriptions of how they may be used to better design tailings slurry deposition. In addition, planned further advances in tailings testing methods are briefly described.CITATION:Williams, D J, 2018. Recent advances in tailings testing methods, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 8–37 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By W P. Breytenbach

"The phased application of statistical process control (SPC) infers that processes are classifiable as pre-SPC (or phase zero), phase I and phase II processes, with different objectives being pursued in the different phases. Phase zero processes, defined as processes affected by assignable causes of variation, are characterised as follows: out-of-control with unknown autocorrelation structure having an unknown statistical distribution not performing consistently on target with minimum variability potentially incapable of conforming to the product specifications. The objectives of phase I SPC is to obtain estimates of the mean (µ), variance (s2), probability density function (f(X)) and the autocorrelation structure, as well as transforming the process into a phase II process (defined as a process conforming to specifications and performing on target with minimum variability). As in any other type of research or pragmatic improvement intervention, sampling is required is to achieve these objectives. The challenge of deciding a phase I sampling plan is multifarious since it has to cope with the aforementioned effects of assignable causes and provide for rigour estimates of the unknown parameters. Furthermore, deciding sampling plans in phase I invariably presents a classical catch-22 situation: appropriate sampling is required to determine the autocorrelation structure of a variable, but knowledge of the autocorrelation structure is required to formulate an appropriate sampling plan. This paper suggests, for random variables, guidelines to formulate sampling plans, and presents a methodology to estimate the inherent process parameters of process variables and an approach to identify assignable causes in phase I. CITATION:Breytenbach, W P, 2014. Rational sampling and standard deviations for random variables in phase i application of statistical process control, in Proceedings Sampling 2014, pp 141–154 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 29, 2014

By C S. Kelsey, J R. Kelly

Australia is presently enjoying the fruits of a booming iron ore market. Expectations are that market strength will be supported in the short to medium term by increasing feedstock demands from steel mills, as world economies rebuild post-Covid-19. However, as cost and environmental pressures increase the longer-term market outlook will be dominated by product quality. The ‘flight to quality’ will place increasing demands on direct shipping ore miners as they compete to maintain their standing in the iron ore marketplace. China will progressively disengage from its dependence on Australian imports, leaving miners under increasing pressure to boost product quality and diversify outlets globally. Australia has vast deposits of low-grade magnetite ores located mainly in remote and arid regions of the continent. This paper proposes a dry grinding and magnetic separation process to produce premium concentrate grades from the low-grade ores, to assist in meeting future product quality demands. The premium grade concentrates could be either blended with lower quality direct shipping ores or marketed separately. The proposed dry concentration process involves the pairing of Vertical Roller Milling (VRM), a mature technology widely used in the cement industry, and Planar Magnetic Separation (PMS), a new methodology, which has been developed to the threshold of commercialisation by the private Australian company Cyclomag P/L. Two laboratory prototype planar magnetic separators with field strengths of 1800 gauss and 6000 gauss have been built and tested on a range of magnetite ore types over the past three years. In each case, following grinding to liberation sizes, a combination of roughing and cleaning operations has produced pellet grade concentrates. Vertical roller milling has competed successfully with conventional media milling in grinding cement clinker, limestone and blast furnace slags. A key advantage of dry VRM/PMS processing is its potential adaptability to stepwise modular development, which can minimise initial capital investment, while generating early revenue streams to cope with unpredictable market volatility.

Nov 8, 2021

By A Mirzaghorbnali, D Gilbert, R Burton, J Nemcik, N Aziz

Glass-reinforced polymer bolts, commonly known as fibreglass dowels and fibre-reinforced polymer or plastic bolts or plastic dowels are increasingly applied for strata reinforcement in mines as well as in concrete reinforcement in civil engineering. The most popular dowels used in coalmines are the 22?mm diameter fully threaded type. Fibreglass and plastic bolts are cuttable, easy to handle, lightweight and corrosive resistant. A series of tests were undertaken to evaluate various strength properties of fibreglass dowels. These included tensile failure tests by the double-embedment method, a single guillotine shear test and a double shear test, carried out on dowels installed in concrete blocks, and with punch shear tests. Punch shear tests were used to evaluate the dowel shear strength parallel and perpendicular to the fibreglass strands or elements direction of extrusion. The study found that the tensile strength of the 22?mm diameter fibreglass dowels was in the order of 30?t. In the shear testing, the peak shear load was influenced by the encapsulation grout type and the level of fibreglass axial pretension. Also, there was a nearly fivefold difference in the shear strength value of fibreglass dowels tested parallel as against perpendicular to the dowel axis.CITATION:Aziz, N, Gilbert, D, Nemcik, J, Mirzaghorbnali, A and Burton, R, 2014. The strength properties of fibreglass and other polymer-based dowels for strata reinforcement in coalmines, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 263–268 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

Mine pit slopes in the Pacific Rim are a geotechnical challenge because of the complex geology in which they are developed. Mines are currently being fast-tracked to meet the increase in commodity prices, often resulting in some reduction in ground studies and short-cutting of design procedures. In addition, the resources boom means that skilled personnel are in relatively short supply. At a time when mine pits are getting bigger and deeper, and the engineering is getting more demanding, there is an increased demand on managers to effectively implement the work.   Experience both in New Zealand and the Philippines, display the complex range of geological environments in which pits are being excavated. Working in these conditions has shown that successful geotechnical design requires a strong geotechnical model based on sound geology. An appropriate level of investigation and analyses results in a certain level of understanding for the mine design. There is a point where additional expenditure (on investigation and analyses) is not warranted based on the expected minimal impact on decreasing the level of perceived risk on the project. For most projects in our experience the analytical methods and complexity of geotechnical assessment changes increases as the level of knowledge grows.

Jan 1, 2006

By Cornell J. B

Scaling in Bayer Refineries is a natural consequence of the super-saturated liquors used in the process. The caustic liquor is supersaturated not only with alumina but also silica and calcia at various stages of the process. The basic scaling mechanisms are reviewed and examples of the two basic types, growth and settled scales, are given. Examples include gibbsite scales formed in the precipitators and silica scales formed in heat exchangers. The main factors affecting the rate of growth of growth scales are temperature and supersaturation and are highlighted using a silica scale example. For growth scales chemical cleaning rates can readily be predicted from kinetics and an example for a gibbsite scale is given. For settled scales the growth rate cannot be predicted and the hydrodynamics within the system have most effect. There is no simple method to predict the potential for chemical cleaning of settled scales; some of the relevant issues are discussed, in particular methods to identify the cementing phase in the scale. An example of design considerations for a scaling system, transport of slaked lime, is Given.

Jan 1, 1996

By T Purvis

Xstrata Copper is extending the Ernest Henry Mine with a 6 Mtpa sub-level cave (SLC) mine being constructed under the pit. The SLC mine will maintain the EHM operation until 2024 after the pit is completed in August 2011. In February 2008, the first cut of the new underground mine at EHM was fired with the start of an exploration decline. Since then Xstrata Copper has continued the development and construction of a SLC mine. During this process a number of challenges arose, some of which had not been anticipated in the planning stages, that in turn has been addressed to ensure the development continued. The challenges have been many and varied and range from setting up the portal area and commencing the exploration decline development in an active large open pit, to management of underground water. Further challenges were presented by the effects of the GFC on investment recommendations, with the scale of the mine varying from a shaft mine to a smaller scale trucking only mine in mid-2009 and back to the full shaft mine in late 2009. The effect was the parallel development of two separate mining scenarios, with the challenge of maintaining commonality for as long as possible to keep both options alive until the final board approval was obtained. In 2010 the RSPT caused further impacts. This paper will describe the current progress of mine development as well as how the various challenges have been met and some key lessons learnt from these experiences.

Mar 21, 2011

By J D. Illescas, S N. Arnold, D R. Shaw

Ion exchange (IX) as a primary production technique has been applied commercially since the 1950s; its application in the uranium industry continues to be widespread and is utilised to a lesser degree in the gold industry. The majority of ion exchange applications, outside of gold and uranium, have primarily been for secondary metal recovery and impurity removal. Newer developments in the application of ion exchange, as well as changes in regulatory requirements, are bringing about the wider use of ion exchange as a primary production technique not only for high value metals such as uranium, platinum group metals (PGM), refractory metals and rare earths, but also looking at base metals such as nickel and copper. The ability to build lower-cost, safer, less polluting processing plants with smaller footprints is driving a greater interest in IX, with the main competitors remaining solvent extraction and carbon-in-pulp/leach. This paper discusses a number of areas where IX has been applied and its advantages compared with other techniques.CITATION:Shaw, D R, Arnold, S N and Illescas, J D, 2012. Ion exchange in hydrometallurgy - Secondary metal removal or primary production technique?, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 17-22 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By E J. Sellers, A Cocker

Movement of the fragmented rock mass is an inevitable consequence of open cut blasting. Uncontrolled, unaccounted movement from blasting commonly causes ore loss and dilution from waste mixing. Therefore, the prediction of the post-blast location of both ore and waste is vital in grade control and of direct interest to mining geologists. Direct measurement techniques have matured significantly over the past decade, but their use remains expensive and labour intensive. Access and safety issues are further disincentives to regular movement monitoring. What is needed is a combination of direct measurement to establish baselines and reliable predictive modelling.The W H Bryan Mining and Geology Centre of the University of Queensland has pioneered 3D blast movement modelling using ‘physics engines’ to handle in-flight collisions and predict the final resting place of blasted material. Open cut metalliferous mines are a demanding environment for this style of modelling as they can involve complex geometries and variable buffering, which leads to inconsistent confinement. A version of the model designed to deal with these complexities is under development. A well-controlled field trial was needed to validate this new version.A validation trial was completed at a gold mine in South-East Asia. The aim was to increase throughput by increasing the blast powder factor without losing grade through dilution and mixing with waste. Four blocks were blasted to identify the effect of bench height and face confinement on ore movement, fragmentation and process throughput. The powder factor and blast timing were kept constant. Movement of the broken rock was measured by placing blast movement monitors at known positions in the block and then locating them after the blast. The majority of sensors were recovered, providing a unique insight into blast movement dynamics and generating a substantial data set for model validation.The model (called ‘MetaMove ‘) was calibrated for one blast and applied to investigate the extent of grade loss and possible mitigation strategies. Conventional mining techniques that involved firing across the strike of the orebody, and no post-blast boundary adjustment of the ore/waste boundaries prior to digging, were found to cause up to 44 per cent loss of high-grade ore, depending on the grade distributions. Post-blast adjustment of the ore/waste boundaries can negate this loss. The model indicates that altering timing and ensuring that the block boundaries are well confined can further constrain the movement of ore/waste boundaries. Thus, the model can be successfully applied to minimise grade dilution and limit misclassification of ore as waste whilst using higher powder factors to increase mill throughput. Application of a calibrated model to move ore/waste boundaries prior to digging will enable the production geology team to add significant value to the mining operation.CITATION:Cocker, A and Sellers, E J, 2014. Modelling blast movement for grade control at an open cut gold mine, in Proceedings Ninth International Mining Geology Conference 2014 , pp 377–386 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By D McCoy

Titanium feedstocks are the building blocks of the titanium value chain. They can be mined directly, as is the case for ilmenite, leucoxene and rutile, or manufactured from ilmenite by extracting various quantities of non-TiO2 components from the ore by chemical and/or thermal processes.While feedstocks can be grouped into categories of materials with similar characteristics, they are essentially unique products from very different mining locations around the world. In fact, no two feedstocks are exactly the same. As such, the variations between the available feedstocks, in combination with the permutations in processing technologies to turn the feedstocks into titanium pigment or metal, mean that choices between feedstocks are specific to the location in which they are utilised.In this paper, the authors examine the key requirements of titanium feedstocks to the TiO2 pigment and metal sectors. Apart from the well known differences between feedstock choices for the sulfate and chloride process, the more opaque considerations in feedstock sourcing are examined.

Oct 5, 2011

By G R. F Alvear Flores

Mineral resources are becoming more complex in composition and structure making it more difficult to produce clean concentrates for primary metal smelting. In parallel, providing technological solutions to the recycling and recovery of end-of-life materials is becoming more important in moving towards the goal of increasing circularity. The availability of fundamental thermodynamic data and advanced thermodynamic tools greatly assists in evaluating these complexities and their impact on existing and new processes. In addition, it is fundamental to support the economic performance of smelters. This paper describes several examples on how fundamental work can be applied to industrial processing..

Jun 17, 2024

By I M. Platten, S C. Dominy

The evaluation of historical goldfields is currently topical, reflecting a high gold price, improvements in knowledge and technology. and lack of greenfield sites. Many goldfields comprise narrow gold-quartz veins which are structurally complex with an irregular distribution of gold; variable geometry and architecture; and display late deformational effects. The study of historical mine records can be an important tool during early and advanced project evaluation since it contributes to understanding the orebody, exploration target size and setting expectations. The historic Engineer Mine property is located 32 km west of Atlin, British Columbia on the east side of Tagish Lake. The economically important Engineer and Double Decker veins belong to a NNE-SSW vein set. These are narrow, commonly <2 m dilational veins with a minor sinistral strike component and of an epithermal type. Documented ore production between 1910 - 1952 is recorded as approximately 14 263 t at 39.4 g/t Au and 19.5 g/t Ag (for 18 000 oz Au and 8950 oz Ag). The underground workings consist of about 5500 m of tunnels, shafts, raises and stopes over eight levels. The mine is currently being re-evaluated. In 2011, an Inferred Mineral Resource of 41 000 t at 19 g/t Au for 25 000 oz Au (at a 5 g/t Au cut-off) was defined from historical data supported by modern drilling into the Engineer and Double Decker veins. A surface and underground bulk sampling and milling program was undertaken in 2011.CITATION:Dominy, S C and Platten, I M, 2012. Application of historical data to estimate a mineral resource at the Engineer gold mine, British Columbia, Canada, in Proceedings Narrow Vein Mining 2012 , pp 81-100 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012