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The mining industry, both here and internationally, is continually developing increasingly sophisticated software to compute mineral resource estimates, but these processes cannot compensate for a flawed geological interpretation of the geology of the economic commodity(s) concentrations. Quality assurance and quality control (QA/QC) is becoming increasingly common in association with the sampling and assaying practices within the industry. However, it is rare in the case of a geological interpretation associated with mineral resource estimation. Why? In the context of this paper, QA/QC relates to the use of statistical and graphical tools to show that the geological economic commodity concentrations have been appropriately domained. Domaining is essential to improve the chance of getting a mineral resource estimate right. Commodity value and acceptable concentration variation within a mineral resource can be ingredients that make mineral resource estimation difficult to get right. But it is possible to get it right a very high proportion of the time. It is more likely to occur when inappropriate data consolidation is minimised. In any case, inappropriate data consolidation is significantly reduced when the geological interpretation is strongly consistent with the data and it is demonstrable. To achieve quality global estimates of geological domain concentrations, it is essential that the geology of the prospect is understood sufficiently that the deposit is appropriately domained. Appropriate domaining occurs when sample populations are separated in such a way that only data in harmony with each other within the population contributes to the domainÆs concentration estimate. The paper will use four brief case studies to illustrate how QA/QC can be used to display data and validate the underpinning geological interpretation through its associated domaining to get it right when it comes to a mineral resource estimation.

Jan 1, 2007

By C Buchanan

For a long time there has been a known relationship between the northern Heavy Mineral (HM) deposits of the Murray Basin to the extensive north east trending ridges in the area. These ridges have been a targeting tool for exploration and have uncovered some significant discoveries, some of which have turned into mining projects. Bemax’s Ginkgo and Snapper deposits are good examples of how the faulting helped create an economic deposit but also result in significant planning issues in the exploitation of these deposits. Material balance, induration and pyrite issues have been made easier to manage through good geological understanding of the deposits.

Aug 22, 2011

The leaching characteristics of a number of Australian uranium ores were determined under acid and alkaline conditions. Ores from the Ranger, Nabarlek and Koongarra deposits in the Northern Territory were readily leached in dilute sulphuric acid. Suitable processing conditions were: leaching at 35-40°C, pH 1·52·0 and redox potential -475 mV for periods of 16-24h with ore ground to 50 per cent -200 mesh CB.S.S.). Ore from the Roxby Downs deposit in South Australia required leaching at 55°C and a redox potential of -650 mV to achieve a satisfactory recovery. All ores contained refractory minerals which were not leached under conventional conditions, limiting uranium extraction to 86-96 per cent.Carbonate leaching of carnotite in calcrete ores from Yeelirrie and Lake Way in Western Australia yielded uranium extractions of at least 98 per cent. Leaching rates were considerably faster than those reported for other applications of alkaline leaching as the slow oxidation step was not required.

Jan 1, 1979

By G Metzner, R Rodriguez, C Savage

OK Tedi Mining Ltd. (OTML) is in the process of optimising the concentrator performance. One aspect that has been recently implemented is an upgrade of the existing expert control philosophy on the grinding circuit and this will be the topic of this paper. Ore grinding in SAG mills is a multi-input multi-output (MIMO) process subject to several disturbances, most typical being quick acting disturbances such as changes in ore characteristics like hardness and particle size and slow acting disturbances such as ball charge variations and liner wear. The OTML SAG mills treat ore from diverse ore bodies and receive fresh feed subject to large changes in particle size. These circumstances make these mills particularly challenging to control. In this paper, a comparative analysis is presented between the performance of the OTML SAG mill #2 before and after the commissioning of a hybrid control strategy. The strategy uses Expert Knowledge combined with advanced disturbance rejection to reduce the variability of the main process variables, especially pressure and power. It further optimises the overall operation by driving the SAG mill #2 against process constraints (e.g. high power, high motor temperature and high scats recycle rate) and maintaining the operation at or near this point. This strategy is implemented by a combination of the manipulated variables (i.e. fresh feed tonnage and % solids) at any given time.The paper will present trends and a statistical analysis of the comparative results of the mill operation over a period of months, showing a 30% reduction in mill power / pressure variability and a 12% improvement in average power drawn. An increase in throughput was also observed, but cannot be conclusively attributed to the change in mill control due to other changes that were made to the SAG mill #2 during the period of comparison. An additional benefit includes better acceptance from the operators with improved consistency of the SAG mill #2 operation across shifts.The paper will also discuss further improvements envisaged in the continued optimisation of the grinding control circuit.CITATION:Savage, C, Rodriguez, R and Metzner, G, 2013. Hybrid process control strategy for the Ok Tedi Mining Ltd semi-autogenous grinding mill #2 - A comparative analysis, in Proceedings MetPlant 2013 , pp 202-214 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By Trendell B

While objective selection and assessments are an accepted part of employing managers and other staff, they have had only a limited place when selecting mineworkers in Australia. Wambo Mining Corporation has used occupational testing as part of its recruitment process since 1994. For managers and staff in particular, it is considered this has contributed significantly to a 95 % fit of those appointees. In 1997 when Wambo undertook development of a new "on site" subsidiary underground mine called Wollemi Services, they wanted to select the most appropriate people in terms of skill and on the job performance. To achieve this they reviewed and improved their recruitment processes to facilitate selection and transfer of an initial intake of almost 50 staff and mineworkers.One of the issues for Human Resource Management was to provide an environment where employees could let go of previously held (but not necessarily individually believed) entrenched views about individual performance and assessment. It needed to be emphasised that performance could be objectively and fairly assessed. More importantly, the performance being assessed was the application of skills and that new skills could be learnt and individuals could choose to change Behaviour.

Jan 1, 1998

The Effect of Molecular Weight on the Adsorption and Efficacy of Polysaccharide Depressants

Sep 13, 2010

By E Topal

Stopes are used in several underground mining methods. Boundary determination of these stopes is generally based on simple rules of thumb. While several stope boundary optimisation techniques are available, they fail to guarantee true optimum results. The first part of this paper reviews some important stope boundary optimisation studies and proposes a new algorithm to optimise stope boundaries and layouts for underground operations. The second part applies the proposed algorithm to a block model to test its ability to produce optimum results and demonstrate its applicability in a number of different scenarios. The results demonstrate that the proposed algorithm can find optimum stope boundaries and layouts in three dimensions for different stope sizes and economic conditions.

Jan 1, 2009

By A Prinsloo, R Tewu

Automatic control of semi-autogenous grinding (SAG) mills has often been considered complex. Recent experiences at Century Zinc (worldÆs second largest open pit zinc mine) refute this. Together with operating knowledge and appropriate control techniques high quality control is achievable. In this application model-based, constraint, and multiple output control were employed. The control was implemented using standard blocks in the plant DCS. The resulting overall control strategy fulfils the operating objectives and controls the mill with minimal operator involvement over 95 per cent of the time. Previous campaigns using expert systems and complex DCS based control have lacked durability. Their fall into disuse is briefly discussed.

Jan 1, 2009

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 M D. Goodz

MacPhersons Reward gold deposit is in a post-kinematic tonalite intrusion which is a setting different from many other deposits of the Coolgardie goldfield that are hosted in early Archaean tholeiitic sills or meta-sedimentary rocks. Gold mineralisation at MacPhersons Reward consists of auriferous quartz veins that are best developed in the tonalite but extend to the adjacent komatiitic rocks and along the lithological contact zones. The gold-related alteration halo is dominated by biotite-chlorite and pyrrhotite. Unlike many other Coolgardie deposits, the As concentrations are low.

Aug 22, 2011

By E Shilov, R Dixon, L Tovey

BHP Western Australian Iron Ore (WAIO) operations use a suite of slope monitoring systems which are deployed to operational areas based on the ground control risk. Slope Radars are one system used within WAIO, having recently deployed and integrated a network of 22 radar systems across the operations. The integration required the development of supporting network architecture, infrastructure, virtualised hosting, security protocols and a technology support model. This has enabled data transfer between the physical radar systems located in open pits, to on-site offices, a vendor supported remote control room in Indonesia and the WAIO Integrated Remote Operations Centre for data analysis and monitoring of system and displacement alarms 24/7. The typical technical skillset of a Geotechnical Engineer does not include the knowledge and capability to understand and develop the supporting IT infrastructure required for establishing an integrated radar monitoring network. This paper will provide a discussion of the technology considerations for integrating radar systems and highlight the importance of the developed partnerships between internal geotechnical and technology teams and the external vendor team to ensure a reliable, robust and scalable slope monitoring solution.

Nov 29, 2022

By J S. Laskowski

Froth flotation process requires the use of frothers. These important flotation agents are commonly characterised as either æselectiveÆ or æpowerfulÆ and are chosen following general guidelines and verification by laboratory and/or pilot plant tests. Fundamental properties of the flotation frothers have been extensively studied over the last few years. These studies have led to the development of standardised procedures to characterise frothers in terms of their ability to reduce bubble size and to increase foam stability. In this research project, the performance of five frothers in flotation of coal is evaluated and related to the fundamental properties of these agents. Since the recovery of water in the concentrate is closely related to the non-selective transport of solid particles by entrainment, the tested frothers are also assessed in terms of their ability to promote the transport of water towards the froth collection zone, both in absence and in presence of solids.

Jan 1, 2005

By T Baumgartl, C Gonzales, A Soliman, M Edraki

A soil cover isolates potentially acid-forming (PAF) mine wastes from atmospheric interaction and thereby mitigates acid mine drainage. As a cover that comprises either a single layer or a composite barrier, it essentially manages percolating rain water from flowing into these PAF materials and minimises air flow as oxygen has low diffusivity in saturated soils. However, the availability of suitable soils as cover materials is limited, especially in arid and semi-arid regions where weathering rates are low.This paper investigates the potential use of mine wastes as cover materials in a water-shedding soil cover in north-west Queensland. Four cover trial plots were built using mine wastes as cover materials. Each 2.3 m cover trial plot consisted of a 1.5 m soil cover made up of waste rocks and fines, a 0.5 m drainage layer that consisted of 0.1 m waste rock aggregates and a base layer made up of blended mine tailings. The hydrologic properties of cover materials were determined by in situ measurements and laboratory experiments, which, in turn, were used as input in a numerical model that described the cover’s transient soil moisture profile. The successful performance of the cover is reliant on the long-term stable geochemical behaviour of the substrate used as cover material. Therefore, investigations were carried out to determine the geochemical properties of the cover materials constructed from benign waste rock using static and kinetic tests, with the objective to increase the level of certainty of the material’s benign characteristics. Consequently, the long-term performance of this water-shedding cover design is described in terms of the physico-chemical characteristics of its outflows.CITATION:Gonzales, C, Baumgartl, T, Edraki, M and Soliman, A, ?2014. Mine wastes as cover materials in a water-shedding soil cover in north-west Queensland, in Proceedings Life-of-Mine 2014 , pp 261–270 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By D Craw

The Old Man Range, south of Alexandra, in central Otago consists of a package of highly folded greenschist facies schist of the Wanaka lithologic association. The range is crosscut by several east to ENE-striking high angle gold-bearing quartz veins, (eg Whites Reef and Grays Reef), which were extensively worked in the late 1800s. The range is bounded on its east side by the Old Man Fault, which separates these rocks from generally flat lying and planar Caples Terrane schist. To the west of the Old Man Fault, about halfway up the range, a large subparallel, 100 m wide fault zone strikes NNW and appears to cut off the historic veins. The fault zone consists of highly sheared and folded rocks and numerous high angle cataclasites and centimetre-scale clay gouge zones. Hydrothermal alteration is not apparent and the individual faults and shears are clay altered, possibly due to weathering, without visible quartz veins. Gold, limonite pseudomorphs after pyrite and rutile are concentrated in some of the narrow cataclasites and gouge zones. These mineralised structures are texturally similar to the gold-bearing reefs and may be structurally related. It is postulated that the NNW-striking shear zone and ENE-striking veins may be a conjugate array formed during a period of Cretaceous normal faulting.

Jan 1, 2004

Prominent among the ore minerals at Mt. Ellison, in the Brock's Creek district, Northern Territory, are a number of copper-bismuth sulphides wittichenite, aikinite, emplectite, in association with nativebismuth, chalcopyrite, bornite, chalcocite, sphalerite and linnaeite.Linnaeite and aikinite formed first and were followed by native bismuth. Wittichenite was later and substantially replaces earlier minerals. Replacement of aikinite by wittichenite has produced secondaryor reaction bismuth.INTRODUCTIONThe Brock's Creek district of the Northern Territory lies to the south east of Darwin and has been the locale of intermittent mining of small but rich deposits of diverse ore type. Gold, tin, and copper ores were recovered especially between 1890 and 1910 with minor exploitation up to the present time. Copper ores were of prior importance, the main production coming from supergene enriched deposits of chalcocite.The mines are situated in strongly folded Precambrian strata comprising slates, sandstones, volcanics and amphibolites with replaced haematitic rocks (Sullivan, 1953). The strata in the Brock's Creek area immediately north of the Darwin-Birdum railway line are domed around a roughly circular granitic mass some 5 miles in diameter. The Mount Ellison mine is located near the N.E. margin of the granite in metamorphosed basic country rock.Study of a series of polished sections from Mt. Ellison revealed the presence of linnaeite, chalcopyrite, bornite, aikinite, wittichenite, emplectite, bismuth, sphalerite, and chalcocite. With the exception of sphalerite and emplectite each of these minerals is prominently developed and intimately intergrown with the other constituents.

Jan 1, 1963

Study on Influence that Styrene-Phosphoric has on the Surface Property of Rutile Minerals

Sep 13, 2010

By M J. Nugus, J G. McLellan, T G. Blenkinsop

High fluid pressures and deformation have been instrumental in the formation of high-grade gold lodes at the Archaean granite greenstone 12 Moz Sunrise Dam gold deposit in Western Australia. Historically, predicting the location of these lodes has been difficult due to the irregular nature and high-grade nugget characteristics of the deposit. Recent exploration successes and the discovery of the Vogue system have led to an improved knowledge of the deep extents of the mine. This new structural and gold distribution data has enabled a new 3D interpretation of the system and has provided a better insight into the links between deformation, fluid pressure evolution and gold deposition. Here we employ 3D geomechanical and coupled fluid flow modelling to better constrain areas of high strain partitioning, rheological failure and focused fluid flow, which provides a substantially increased predictive capacity for further within-mine exploration. The localisation of deformation in and around the main felsic porphyry and major shallow shear zones provides critical insights into fluid pathways that have contributed to the distribution of fracture networks and ultimately gold deposition during late stage deformation events. Understanding the relationship between deformation events, fluid pressure evolution and the partitioning of strain is paramount in understanding the distribution of gold and for focusing on future target areas.CITATION:McLellan, J G, Blenkinsop, T G and Nugus, M J, 2013. Fluid pressure, geomechanical evolution and predictive targeting of the Sunrise Dam gold deposit, Western Australia, in Proceedings World Gold 2013 , pp 419-426 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

The southern portion of the Swan Coastal Plain, a geomorphological element formed since late Tertiary times, contains commercially exploitable accumulations of ilmenite, zircon, rutile and monazite associated with a series of raised shorelines. The location of the deposits is controlled by a locally outcropping Archaen granite/ granulite complex and a sea current pattern determined by local geography and a prevailing wind direction. A progression from medium to high titanium ilmenite is evident parallelled by progressive leucoxenisation as the age of the deposits increases. Variations in trace element content accompany this process. Circulating groundwater has caused vertical mineralogical variations within individual deposits and by precipitation of iron has formed layers of hardpan.The Geographe Bay deposits are of important economic significance.INTRODUCTIONObservations made during the course of a brief survey of the southern portion of the Swan Coastal Plain provide an outline of the geology and mineralogy of the mineral sand deposits of the area. This preliminary study will require considerable modification in the light of more detailed work in the future.REGIONAL GEOLOGYThe Geographe Bay area is situated in the south-west corner of Western Australia between longitudes 115° O'W. and 116° O'W. and latitudes 33° 15'S. and 33° 45'S.The general geology of the area is shown in Fig. 1 where the control of the physiography exercised by the Cape Leeuwin-Cape Naturaliste basement ridge is readily apparent. Between this ridge and the Precambrian east of the Darling fault lies the southern part of the Perth basin which contains outcropping Jurassic to Recent sediments and lavas (McWhae, et al., 1958).The Leeuwin-Naturaliste ridge is the exposed portion of L Assistant Production Managcr. Laporte Titanium (Aust.) Ltd.

Jan 1, 1964

A calibration of the Frantz isodynamic magnetic separator relates the current in the electromagnet and the transverse slope of the chute to the specific susceptibility at which separation is being effected. In addition to providing a rapid measure of the specific susceptibility of minerals and composite grains, the calibration provides a guide to operation of the Frantz isodynamic separator for mineral separation, and to the nature of composite grains. The most sensitive magnetic separation is obtained by using the highest practicable current and transverse slope, and the lowest practicable longitudinal slope.INTRODUCTIONProbably all minerals have a magnetic susceptibility measurable by sensitive techniques. However, magnetic separation between minerals which have low but different specific susceptibilities, and which for many purposes are considered essentially non-magnetic, has only become practicable with the development of the Frantz isodynamic separator.The construction and principle of this highly sensitive separator has been described by S. G. Frantz as an appendix to a description by 'Gaudin and Spedden (1943) of its application to the separation of sulphides constituting mill products.Various publications (e.g. Hess, 1949, Hutton, 1952) refer to its use in separating the mineral constituents of rocks, ores, and unconsolidated sands.As used in this study the Frantz isodynamic separator consists of a vibrating chute mounted centrally between the pole pieces of an electromagnet (Fig. 1). This unit may be inclined in any direction by the universal mounting, and the electromagnet current is continuously adjustable from 0 to 1·5 amperes.

Jan 1, 1957

By R Young, D OÆSullivan

When Centaur Mining and Exploration produced nickel metal fromlaterite ore at its Cawse nickel project in January 1999, a new era in the nickel industry was heralded in. One of three new laterite projects commissioned that year, new technology and a unique process design has been combined at Cawse to launch what will be amongst the worldÆs cheapest nickel production. However, the road to success has proven to be long and challenging. This paper explores CentaurÆs approach to the Cawse start-up and discusses a number of issues that have been confronted and overcome. * Originally published in the Proceedings of the Seventh MillOperatorsÆ Conference, published by The AusIMM.

Jan 1, 2001