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As part of the response to the increased demand for products such as iron ore, coal and gold many resource companies have identified the need to develop strategies focused on attracting high demand professionals and retaining current employees in the business. Recent graduates are entering a time where they can expect high starting salaries, attractive benefits and lifestyle options. At the same time high work expectations and large demands on both personal and professional development will also be the norm. Some of the challenges faced may include high demands on performance, working with limited resources, long hours, and tackling unfamiliar areas of work with little guidance. However, managing your career and these challenges effectively can give you valuable experience in a short amount of time. By offering situations from my relatively short, yet active, career in the mining industry during these boom times I will raise some key points on how to best leverage your commodity and make the most of a bullish market.

Jan 1, 2006

By R Burgess-Limerick, D Lynas

A number of standards and guidance materials currently exist to assist equipment designers. The ISO process, however, is a formal process and change often lags behind technology development. In some cases, this may result in weak or ineffective standards that need to be written in general terms to accommodate future technology developments, meaning some standards may only establish minimum requirements and not be overly helpful to equipment designers, in particular when designing for workforce diversity and inclusivity. By contrast, advisory information as issued by various mining regulatory bodies is able to respond more quickly to changes in technology. Standards do however have a safety and productivity focus providing design consistency between equipment manufacturers, a basis for auditing purposes, assistance in mining regulation and compliance, and in the development and application of safety management systems. As an example of challenges facing equipment designers, ISO3411 (2020) provides data approximating the 5th, 50th and 95th percentile of the ‘earth-moving machinery operator population’ for numerous static dimensions relevant to the design of earth-moving equipment. These data are then utilised in ISO6682 (2020) to provide recommendations regarding the location of controls. Attempting to utilise the data provided in ISO3411 (or other sources of static anthropometric data) creates further challenges for equipment designers, in that reference percentiles is problematic for design purposes. There is no ‘5th or 95th percentile operator’ as individuals vary along each dimension (Robinette and Hudson, 2006). Although dimensions have some degrees of correlation, when multiple dimensions are considered, the range of individuals which fall within a given range on all dimensions reduces substantially. For example, only about 82 per cent of individuals in a population will fall within the 5th to 95th percentile ranges for both height and weight. The more dimensions are considered, the smaller the range of people who actually ‘fit’ the description.

Apr 16, 2024

By Mousset-Jones P, McPherson M. J

This paper explains and discusses a computer program developed to deter- mine the optimum combination of fan pressures that will give a required distribution of airflows in a mine ven- tilation system. The program is based on an existing simulator, VNETPC and two experimentally developed relationships: (1) linearity between fan pressures and added regulator resistances and (2) a non- linear convex function relating the system air power and the fan operating Pressures.

Jan 1, 1988

By G R. Hancock

A common and cost-effective method for post-mining landscapes is to construct linear hillslopes with a break in the hillslope at appropriate distances to reduce hillslope length and resultant erosion risk (Figure 1). The break in slope occurs at a point that has been found by local experience to be appropriate for the materials and climate. Further enhancement of the linear hillslope may be assisted by surface treatment such as ripping (Saynor, Lowry and Boyden, 2019) (Figure 1). Firstly, ripping introduces surface roughness which breaks up flow paths reducing flow velocity thereby reducing erosion potential. The depression produced by the ripping acts as a trap which captures water, sediment and organic matter

Aug 2, 2023

By Gang L

Seventy-nine gold deposits and prospects have been discoveried in the Jiamusi region of northeast China, and constitute one of the most important gold metallogenic belts in China. All these endogenic gold occurrences can be subdivided into three main deposit types: (1) porphyry related; (2) metamorphic-intrusive hosted, and (3) sediment-hosted deposit. The first two types of gold deposit are spatially and temporally related to Mesozoic Yanshanian granitoid intrusions with hydrothermal activity channelled along crustal-scale fissures. The ultimate cause of the Yanshanian magmatism is considered to be the subduction of Pacific oceanic lithosphere beneath the Eurasian continent. In contrast, The chemical sediment-hosted deposit is typified by the Dongfengshan gold deposit, and genetically related to Proterozoic sedimentation and Mesozoic igneous activities.

Jan 1, 1995

By Moore R. F, Macias L. F

The Filbara region of northwestern Western Australia contains several known occurrences of mafic/ultramafic rock assemblages which may host platinum group element (POE) mineralisation. This paper deals with occurrences at Munni Munni and Andover. The Munni Munni complex is of particular interest because it is known to contain PGE mineralisation and is currently undergoing active exploration. The US/Australia Joint Scanner Project of October 1985 collected airborne scanner data for the BMR over Munni Munni. Such an ultramafic-mafic complex had not been previously researched with advanced remote sensing instrumentation. Extensive investigation of data from the NSOO1 (Thematic Mapper Simulator) scanner resulted in successful differentiation of gabbroic and ultramafic rocks, and also subdivision within the ultramafies. Similar differentiation could not be achieved using conventional Landsat MSS imagery and aerial photography. Encouraged by those results and in support of BMR field research into the mafic-ultramafic suites of the region, data from the Landsat Thematic Mapper (TM) instrument were investigated to attempt differentiation of the ultramafic and mafic rocks in the Andover complex some 50 km to the northeast of Munni Munni.

Jan 1, 1988

A vital ingredient in ensuring that metals exploration companies, working in the developing countries of the Pacific Rim, support the development of national geologists is making such a learning program cost-effective. There is a wide spectrum of learning needed in the development of these explorationists: the technical and conceptual skills to carry out exploration efficiently, the professional and managerial skills to apply the exploration in the work situation, the personal attributes required to manage their exploration effectively, and a company organisation that allows them to learn and use these skills and attributes.

Jan 1, 1995

Most internationally traded iron ore resources are derived from multiple mine sites, transported to a port facility where they are blended and possibly further processed prior to shipping. Provided the proportion of contributions varies over a number of shipments an estimate can be made of the bias introduced by mine site sampling, analysis and materials handling systems, using zero-intercept multiple linear regression. Further regression applied to the residuals allows the error variances for the source mines to be estimated. Various sampling strategies are used by the industry. All have shipment-loading sampling on which payment or at least provisional payment is based. In most cases sampling prestockpile is used at mine sites to verify estimated production grades. Train grades are estimated from mine stockpile grades and in some cases train grades are verified by port input sampling. The methodology used is presented in this paper. Simulated data have been used and do not reflect the actual performance of any operator. The merits of the various systems and the implementation and potential limitations of our method are discussed more fully in a companion paper (Ziegelaar and Everett, 2010).

Mar 1, 2010

By S R. Grano, M Vera

This paper deals with two separate case studies investigating the froth phase performance and characterisation of two industrial rougher/ scavenger flotation circuits. Froth phase performance was quantified using a mass balance approach to estimate froth zone recovery. Measured characteristics of the froth phase included frother solution concentration determined by gas chromatography, and the time taken for an equilibrium froth sample to decay to one-half of its original froth height. The latter measurement is referred to as the æfroth half-lifeÆ and is strongly linked to froth stability. Special methods and techniques developed to preserve frother in solution and to measure froth half-life are briefly described. The frother type in the first case study was a mixture of straight and branched alcohols, whilst the frother type in the second case study was a mixture of alcohols, aldehydes and triethoxybutane. The first case study focussed on a flotation circuit treating a low-grade ore containing only a small fraction of floatable copper sulfide minerals, while the second case study focussed on a flotation circuit treating a higher grade complex sulfide ore containing significant quantities of chalcopyrite, galena, sphalerite and pyrite. It was found that froth zone recovery of valuable mineral generally decreased down-the-bank of the two industrial rougher/scavenger circuits. Moreover, decreases in froth zone recovery significantly limit the overall cell recovery of valuable mineral achievable from the plant scavenger cells. However, the decrease in froth zone recovery could not be linked to the removal of frother from the pulp solution to the concentrate product in the preceding rougher flotation stages. Measurements of residual frother in solution suggested that, approximately, only five to ten per cent of the added frother was removed into the rougher/scavenger concentrate, with the remainder appearing in the scavenger tailings. This finding suggested there was apparently adequate frother in solution in the scavenger stages.

Jan 1, 2005

By Barnes E. L S

With the introduction of diesel powered loading and hauling equipment, a number of Australian mines producing less than one million tonnes per year from shallow orebodies have been dev- eloped by decline. This method of entry has the advantage of providing both flexible access and early prod uction. However, as the depth of mining increases so does the operating cost of haulage, due to the need for more trucks. This cost, together with increased capital requirements for both equipment and infrastructure, leads to the point where the alternat- ive of shaft hoisting must be con- sidered. With an established decline it is possible to provide an ore hoisting shaft using a drilled raise with subsequent stripping to a suitable size. Using DCF techniques and known equipment operating and capital costs, an economic comparison of the two systems is made to determine the limit- ing depth to which truck haulage can be used.

Jan 1, 1973

There has been much debate in the past as to whether the Australasian Institute of Mining and Meteorology ("AusIMM") should issue valuation guidelines in addition to the ASX and NCSC requirements. My experience in preparing independent expert reports has been that "best practice" sets higher standards than any laws or requirements set out by the ASX and NCSC. This is where I see the AusIMM coming in.

Jan 1, 1989

During Gepp's lifetime, Australia was in the forefront of science and art in metallurgical practice. This did not come easily for although blessed with a unique mineral deposit at Broken Hill large in size and rich in values much courage and daring was needed in the development of processes whereby they could yield the best results.The resultant development of the flotation processes at Broken Hill is one of the most important inventions of the 20th century.

Jan 1, 1993

The past decade has seen a great increase in activity in deep seismic reflection profiling of the continental crust. Some 20 countries have conducted field experiments and the total length of deep seismic profiles surveyed to date is approximately 25,000 km. This total is very large compared to the quantity of such data that existed previously, but very small compared to the total length of seis- mic profiles of the shallow crust carried out for petroleum exploration, which some- times has exceeded 600,000 km on land in one year alone and 1,600,000 km/yr on land and sea. Furthermore, 25,000 km of seismic pro- filing corresponds to exploration of only a tiny fraction of the total volume of the entire continental crust. Thus at this stage of development of the subject, one must be wary of generalizations that are based on these limited data and then ex- tended in scope to include the crust everywhere. The state of the subject is such that virtually every new seismic line reveals totally unexpected seismic fea- tures, a sign that the subject is in its major discovery phase and a warning to the generalizers. Nevertheless, in addition to much new information on deep crustal structure in specific locations, some broad consequences of application of this powerful geophysical technique to a region of the earth not pre- viously explored in this manner are be- coming clear. One is that, as seismic data on the deep continental crust become more abundant and more revealing of complexi- ties, the deep crust can be far better re- lated to rocks at the surface. Conse- quently, the geological style of reason- ing is now being extended from its normal domain of the near-surface to include the deepest crust in a comprehensive story of the evolution of the continents. This change is a subtle but important one and is evident, for example, in some cross sec- tions of the North American Transect Pro- gram, which show surface geology extended in a consistent, though speculative, manner to the top of the mantle. In other words,

Jan 1, 1987

By C Li

Removal of gangue minerals from ilmenite concentrates can beaccomplished by relatively low temperature roasting in controlled gasatmospheres to selectively enhance the magnetic separationcharacteristics of the ilmenite. At roasting temperatures below 800¦C the magnetising reactions are often not consistent with phase equilibria considerations. Metastable phases can nucleate and control the roasting products. In weathered ilmenites the phase assemblages and microstructures in the altered ilmenite grains can influence the roasting reactions. In this paper we give an overview of the phase chemistry of chemically weathered ilmenites and of metastable phases formed by low temperature roasting. We also report the results of roast experiments conducted in a neutral gas atmosphere. Major increases in magnetic properties after short roasting times at low temperatures were obtained for a range of ilmenite concentrates. For example heating a secondary ilmenite concentrate from Western Australia for 15 minutes in nitrogen at 600¦C gave an increase in the three kilogauss magnetic fraction from three to 92 wt per cent. The solid state phase changes accompanying the inert atmosphereroasts were characterised by combining elemental analyses withquantitative phase analyses of the ilmenite concentrates and their roast products. It was found that the phase reaction that is principally responsible for the increase in the magnetic properties of weathered ilmenites involves a transformation of disordered ferrous-containing pseudorutile to an ordered ilmenite-hematite solid solution containing typically ten to 35 mole per cent of the hematite component. Examples are given of the application of the inert atmosphere roast to effect separations of ilmenite from gangue minerals.

Jan 1, 2001

The paper discusses the characteristics of Be-zymianny activity during the last 2500 years. Three periods of increased activity have been identified which are the eruptive cycles lasting for 100-400 yrs. The periods of high activity fall on the fol-lowing time intervals: 2400-1700 yrs ago, 1350-1000 yrs ago and from 1955 ixp to the present time. The 1955-1956 catastrophic eruption after a long period of repose (about 900-1000 yrs) opened a new cycle of activity of the volcano which is continuing to-day. Several decades are distinguished in activity which differ in character and intensity of eruptions.

Jan 1, 1990

A sequence of ultramafic units, very well exposed in Munro township in the Abitibi areal, of the Cahadian Shield, exhibit features which indicate that they are sub-aqueous extrusions. They occur within a sequence of tholeiitic pillow lavas, thin graphitic sediments. and large differentiated sills. The units range from a few metres to more than 250 m in length and less than 1 m to over 30 m in thickness. Over 60 individual units, occurring as flat pancakes on top of one another, make up a total exposed thickness of 150 m. The units have formed from a magma composed of a very olivine-rich picritic liquid carrying up,to 40 per cent olivine phenocrysts in suspension. Different units display a variety,of cross-sectional profiles. As an example of the most extreme type of profile, a typical unit 2 m thick consists of a cap of highly jointed fine-grained quenched rock, 10-30 cm thick, which becomes coarser downwards, grading into a zone composed of radiating and criss- crossing skeletal olivine crystals forming the well-known spinifex texture. This becomes even coarser-grained downwards, with "books" of parallel platey olivine crystals developing sub-perpendicular to the plane of the units. Beneath this zone, which may be up to 1 m thick, there is an abrupt transition to a cumulus-textured rock composed of rounded

Jan 1, 1973

By Hagarty KA

At the northern margin of New Guinea there is a fundamental problem related to the relative timing of arc- continent collision(s) represented in the Papuan Fold-Belt (PFB) and backarc spreading in the Caroline basins. New fission track dates from basement and sediments within major anticlines of the PFB indicate that uplift occurred at 4.0 ¦ 0.5 Ma. The timing is consistent with the fold and thrust shortening (more than 100 km) of the PFB which occurred in the Late Miocene/Early Pliocene as evidenced by the deformed Miocene carbonates and Pliocene molasse deposits. However, in northern Papua New Guinea, earlier work has suggested that ophiolite emplacement and associated metamorphism occurred in the late Oligocene/early Miocene.The evidence suggests that the late Miocene/early Pliocene deformation was of considerably greater magnitude than the earlier obduction event. The Caroline Plate lying north of New Guinea has been interpreted as a backarc basin which commenced spreading in the Eocene and ceased spreading in the Late Oligocene (about 28 Ma). The remnant arc presently docked to New Guinea was active in the Eocene and Oligocene and is believed to be the arc related to the formation of the Caroline Plate. The cessation of spreading of the Caroline Plate has previously been interpreted to be due to arc continent collision during the Late Oligocene/Early Miocene, but such a collision is now known not to have occurred. In the Cretaceous and Palaeocene subduction was to the south beneath New Guinea, but "flipped" in the Eocene to give a north-dipping subduction zone far to the north of New Guinea, driving Caroline Plate backarc extension. This backarc basin reached a limiting size at about 28 Ma resulting in the end of subduction. With the continued northward movement of Australia, Mesozoic oceanic crust was obducted southward onto the New Guinea margin in the Late Oligocene/Early Miocene. In the Miocene south-dipping subduction beneath New Guinea commenced until the now extinct Caroline Plate arc collided with New Guinea in the Early Pliocene, causing extensive regional compression and sinistral strike-slip faulting. This new tectonic framework suggests that backarc basins reach a limiting ridge-trench distance of 1000-1500 knm, beyond which "subduction-pull" cannot drive further spreading so subduction and spreading are terminated.

Jan 1, 1987

By C J. Ptacek, J G. Bain, D W. Blowes

The passive interception and in situ treatment of groundwater using permeable reactive barriers (PRBs) has, within the past decade, become an accepted remedial approach to the control of plumes containing dissolved organic and inorganic contaminants. Since the first applications of the technology in the early-1990s, there have been several field-scale PRBs that have provided excellent treatment of dissolved metals in groundwater. Additional commercial applications and demonstration projects continue to be developed. Three field-scale applications and supporting laboratory columns have shown that several thousands of milligrams per litre of sulfate, more than 1000 mg/L iron, and several tens of milligrams per litre of other metals can be removed from groundwater by PRBs that promote sulfate reduction. The reactive materials, which incorporate various forms of organic carbon, promote microbially mediated sulfate reduction, the generation of hydrogen sulfide, and the subsequent precipitation of sparingly soluble iron and other metal sulfide minerals. Effective performance has been achieved by PRBs installed at a mine-tailings impoundment in 1995 (Sudbury, Ontario) and at an industrial facility (Vancouver, British Columbia). These PRBs have removed iron and other metals from groundwater. Similar materials were also used to create reactive layers within test cells directly in a tailings impoundment in 1999 (Timmins, Ontario) with the objective of removing iron and sulfate from the pore water before it migrates from the tailings impoundment. Zero-valent iron (ZVI) has been shown to provide excellent removal of chromium (VI) in a PRB, which was installed at the US Coast Guard facility in Elizabeth City in 1996, by reduction and precipitation reactions. Laboratory tests have also shown that ZVI reduces As(V) to As(III), which is subsequently removed from solution by co-precipitation with iron oxyhydroxides. In groundwater containing sulfate, ZVI and mixtures containing organic carbon can promote sulfate reduction and the subsequent precipitation of sparingly soluble arsenic and other metal sulfides. A trial PRB system was installed in 2001 and was shown to attenuate arsenic and other electroactive metals in groundwater at an industrial facility in northwestern Ontario. Basic oxygen furnace (BOF) slag, a waste material generated by the steel industry, has shown excellent potential for the removal of phosphate, elements such as arsenic and water-borne pathogens from groundwater in field and laboratory tests.

Jan 1, 2003

By Butt C. R M

Resurgence in Au exploration during the past decade has been characterised by a considerable emphasis and dependence on geochemical procedures. This has been made possible, firstly, by marked improvements in analytical sensitivity over those previously available and secondly, of particular importance to exploration in Australia, by a better understanding of the distribution of Au in the regolith, which has led to the optimisation of sample media. These developments have given exploration companies the ability to seek and detect subtle and widespread geochemical signatures of concealed Au mineralisation and provided an enhanced capability to interpret the data. As a consequence, several new discoveries have been made, even in areas that have been intensively explored in the past. In the deeply weathered Yilgarn Craton (WA), and in equivalent areas elsewhere in Australia and overseas, Au has accumulated in the upper lateritic gravels and duricrusts of the regolith, probably during humid climatic periods in the Tertiary. The laterites may not only be Au ores in themselves, but research by CSIRO and CRC LEME has shown them to be very important sample media, (eg Anand and Smith, 1992). In many areas, however, the laterite has been eroded and hence is unavailable as a sample medium and chemical modification under more and conditions since the Tertiary has leached Au from the upper saprolite. This has greatly increased the difficulties of exploration, particularly where reliance was placed on sampling between 2 and 15 m of the surface. Further research, however, has demonstrated that, despite this leaching, recent remobilisation of An has caused it to concentrate in a specific soil component, pedogenic carbonate, usually in the top I - 2 m, thereby giving surface expression even to mineralisation that is concealed by over 20 in of leached overburden. Secondary carbonates, commonly referred to as calcrete, may precipitate as calcite and/or dolomite in regoliths where the average annual rainfall is less than about 600 mm. Pedogenic carbonates are those that form in unsaturated (vadose) soil horizons. They are widely distributed in the Gawler and Yilgarn Cratons. In the Yilgarn Craton south of about 30¦S ('the Menzies Line'), they are seemingly more abundant over more basic rocks and towards the south east (Figure 1). In contrast, groundwater calcretes form in saturated (phreatic) environments, typically in the axes of major drainages north of the Menzies Line. These are known to accumulate economically-significant grades of U but not, apparently, An.

Jan 1, 1997

By J Rutter, M NoppT

Ridgeway Gold Mine is part of Cadia Valley Operations which is wholly owned and managed by Newcrest Mining Limited. Ridgeway is an underground sublevel cave (SLC) operation mining approximately 5.6 Mt of gold-copper ore per annum. Ore tracking and accounting systems monitor gold and copper grades, copper mineralogy, host lithology and ore sizing. These factors have material impacts on concentrator throughput and metal recovery. Drawpoint recovered grades are routinely reconciled back to design data to monitor and assess draw performance. Grade control at Ridgeway has been based upon sampling the ore from SLC drawpoint bunds using 15 kg grab samples combined to form 30 kg samples prior to assay. This large sample size was selected in an attempt to representatively sample the coarsely-sized broken ore, the samples collected having a nominal diameter of about 130 mm. The assay results for gold and copper from these samples are extremely variable and the usefulness of the results has been questioned by the mine, particularly given the onerous and OH&S hazardous activity of handling large sample masses. Granulometry testwork at Ridgeway confirmed the extent of the relationship of decreasing sample grade variability with particle size. Based on this relationship, drawpoint sampling tests were carried out using 9 kg samples sieved to -45 mm at the drawpoint site. The gold and copper results from the finer 9 kg samples were significantly less variable than those from the normal, coarser 30 kg samples. The variance reduction was similar to that predicted from broken ore sample theory for the selected sample mass and nominal particle size. This relationship therefore allowed Ridgeway to assess the sample mass and particle size required to achieve a particular precision. In addition to improving the precision, the reliability of assay results from smaller samples from the fine particle fraction for drawpoint control depends on the accuracy of the results. The assumption is that the grade of the finer ore is similar to that expected from the lot, or that if a bias exists, then the extent of this bias is acceptable and consistent enough to be accounted for in the grade control system. The distribution of grade with particle size and the reconciliation of drawpoint sample and mine results is currently under investigation.

Jan 1, 2005