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By J Millard, K Sexsmith

BHP Billiton Diamonds Inc (BHPB) has been mining kimberlite from several pipes at the Ekati Diamond MineTM located 300 km north of Yellowknife since 1997. Processing of kimberlite produces coarse kimberlite rejects (CKR, 0.5 to 8 mm) and fine tailings (less than 0.5 mm). The CKR are trucked to the Coarse Kimberlite Reject Storage Area (CKRSA) located within the drainage area of the tailings impoundment (Long Lake Containment Facility û LLCF). The coarse rejects are wet when dumped and are expected to freeze as a result of annual average site temperatures of about -10¦C. Seasonal thawing occurs along the exposed edges of the pile. Monitoring of the CKR indicates they have consistently low sulfur concentrations (0.4 per cent) accompanied by high acid neutralisation potentials (78 to 337 kg CaCO3/t). Carbonate concentrations vary from 0.9 per cent to 3.4 per cent. The CKR are therefore not potentially acid generating based on conventional laboratory testing. Monitoring of stagnant pools on the tundra downgradient of the CKRSA has shown that water originating from the pile resembles acid rock drainage (ARD). Water pHs can be less than 4, and sulfate concentrations are typically in the thousands of milligrams per litre. Conventional flowing toe seeps are pH neutral but also have elevated sulfate concentrations. Investigations conducted in the summer of 2002 revealed no evidence of in situ acid generation. Pore water chemistry is probably controlled by oxidation of fine-grained pyrite, neutralisation of acidity by calcium and magnesium carbonates and silicates, and freeze concentration of pore water. The acidity observed in tundra pools downgradient of the CKRSA appears to be a result of leaching and mobilisation of iron under reducing conditions at the CKR-soil contact. Downstream of the CKRSA, reduced iron oxidises and is hydrolysed on contact with the atmosphere causing pH depression. BHPB is applying the findings of this study by constructing facilities containing kimberlite on granite pads. These in turn are placed on frozen ground so that the foundations remain frozen and limits contact of wastes with the acidic soils.

Jan 1, 2003

Study on Treatment of Wastewater Containing Heavy Metal Ions Using Modified Oceanic Cobalt-Rich Crusts

Sep 13, 2010

By S A. Myers, T Klein

The Yanacocha mining district is located in the northern Andes of Peru. The project is within the Cajamarca province, 20 km north of the town of Cajamarca and 600 km north of Lima, the capital of Peru (Figure 1). The district encompasses an area of 120 km 2 and is centred on the 78030'west longitude and 7000' south latitude. The project lies at an elevation of 3400 to 4200 masl.

Jan 1, 1999

By R L. Chaney, M Mahoney

Mine and ore beneficiation wastes and smelter contaminated soils often cause phytotoxicity and threaten adverse environmental effects if not remediated. Science has clarified both the risks from soil metals and methods to alleviate those risks that can be applied at low cost. Phytoremediation is a family of plant and agronomy based technologies to deal with environmental aspects of sites requiring remediation. If valid risk assessment indicates that metals comprise risk, phytostabilisation may be used to alleviate that risk for most contaminated sites. In particular, Zn-Pb, Cu and Ni mine and smelter sites are readily remediated by making the soil calcareous and fertile, with added organic and metal sorbent amendments that include soil microbes to ‘revitalise’ the soil. In each case, the soil fertility and causes of phytotoxicity should be clarified by agricultural soil extractions, and the combination of amendments required to improve fertility and reverse phytotoxicity identified and found locally. In contrast with phytostabilisation, phytoextraction/phytomining uses rare metal hyperaccumulator plants and agronomic management to maximise annual phytoextraction of soil elements into plant shoots for harvest, ashing and use as a metal ore. Plants that accumulate more than two per cent Ni in shoots, and yield 10–20 t ha-1 dry biomass yield 200–400 kg Ni ha-1, which has value greater than all common agricultural crops. Considering the value of elements, existence of hyperaccumulator plants and demonstrated agronomic management for Ni phytomining, it is clear that mine sites and Ni mineralised subore-grade serpentine soils can be phytomined economically as an agricultural mining technology. A team developed agronomic methods and improved cultivars of Alyssum, which can be profitably grown on temperate zone Ni mineralised or contaminated soils. Plant species for tropical ultramafic soil materials have been identified. Phytoextraction is also strongly needed to remove Cd from rice soils to prevent human disease from soil Cd.CITATION:Chaney, R?L?and?Mahoney, M, 2014. Phytostabilisation and phytomining – principles and successes, in Proceedings Life-of-Mine 2014 , pp 3–16 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By D M. Hunter, S M. Iveson, K P. Galvin

For low density materials such as coal, density-based fractionation of particles via the sink-float method is relatively simple due to the availability of liquids of suitable density; however, for high density minerals, suitable heavy liquids are less available and those that are available are expensive and pose significant hazards. At best, sink-float separation can be performed up to densities of 4400 kg/m3 with the use of Clerici’s solution at elevated temperatures. Hence the direct measurement of grade-recovery and density-partition curves is problematic. Therefore, in most cases, beneficiation plants must rely on methods such as QEMSCAN, density tracer particles or very limited information to guide them in the design and optimisation of their plants.This paper describes a density-fractionation method utilising laminar flow through a system of parallel inclined channels to generate a series of overflow fractions at different flow velocities. Here the particles are subject to precise hydrodynamic forces with minimal dispersion or mixing. The size distribution of each overflow fraction at a given flow velocity is obtained using a laser particle size analyser, and combined with a laminar flow model to deduce the corresponding density distribution. The paper describes the application of the method to measure the separation achieved using a REFLUX Classifier to obtain the corresponding feed, product and reject ‘washability curves’, and in turn the full partition surface. Approaches used to corroborate the findings are discussed.CITATION:Hunter, D M, Iveson, S M and Galvin, K P, 2017. A batch elutriation technique for the density-based fractionation of iron ore, in Proceedings Iron Ore 2017, pp 195–104 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By S A. Prevec

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Traditional models employed to genetically link associated chromite and platinum-group elements have favoured crustal contamination as the primary process for inducing sulfide and oxide saturation. The association of chromite ores with crustal contamination is well established in the literature. However, in the 1970s (cf Irvine, 1973, 1975), Irvine demonstrated that crustal contamination was in fact problematic as a tool for inducing chromite precipitation in mafic to ultramafic magmas. His results are re-examined here, along with some attempts to reconcile them with the effects of adding Fe to the models. It is concluded that crustal contamination is indeed problematic based on phase relationships alone. However, the role of fluids as a compensating agent is evaluated, which may explain why crustal contamination may indeed facilitate oxide and sulfide precipitation.CITATION:Prevec, S A, 2015. Chromite and platinum-group elements coprecipitation by crustal contamination or magma mixing revisited – genetic and exploration implications, in Proceedings PACRIM 2015 Congress, pp 311–316 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By E Mielczarski

Determination of the adsorbed layer composition and structure at molecular and atomic levels and understanding adsorption mechanisms and dynamics are vitally important for the preparation of surface layers with specific functions. Direct information, at a molecular level, about mineral surface composition, its structure and surface distribution is crucial to perform an efficient separation process for mineral beneficiation. This information is equally important for modifying surface properties of industrial minerals for specific applications such as: fillers, composites, weathering resistance, etc. An understanding of the mechanisms and kinetics of the interaction of first adsorbed organic molecules with mineral surfaces is a fundamental requirement for the prediction and control of the macroscopic surface properties governing the efficiency of separation technologies or new material formulations. The developed infrared external reflection technique has a unique ability to study interface phenomena, at a molecular level, on heterogeneous substrates. The variety, precision and reliability of information about the interface phenomena delivered by this technique is superior to any other single technique. The experiments are fast and non-destructive. High sensitivity (starting from 20 per cent of the monolayer) in situ collected information in a multiphase system, even in the region of strong absorption of the substrate, makes this technique a very valuable experimental tool. The complexity of the recorded reflection spectra, their sensitivity to variations of the optical properties of all bulk and surface components and their spatial distribution in the system under investigation, are in fact the major strengths of this technique. A few examples of the application of this multi-diagnostic technique, for monitoring surface modifications of semi-soluble minerals for selective flotation, will be discussed in detail in this paper.

Jan 1, 2005

Implementation of an Energy Efficient Dry Grinding Technology into an Anglo-American Zinc Beneficiation Process

Sep 13, 2010

The material presented in this paper describes experimental work to determine the effect of variations in suction nozzle design upon inlet flow conditions. Four entrance profile shapes were examined under controlled conditions of slurry flow and it was found that the straight ended nozzles had consistently higher entrance losses than the straight taper or the ellipse, and that the circular arc profile nozzles were the most efficient. Subordinate considerations were the measurement of the quantities and the forces involved.As the work progressed, three distinct phases in the pattern of flow were apparent and the static pressures in each were carefully examined. An inlet zone was found to be unstable in changing boundary conditions, a transition zone was largely independent of slurry density and in a zone of stability the pressures were found to be directly related to the characteristics of the flowing pulp. In this zone pressure measurements were reproducible within ± 2 per cent regardless of changing boundary conditions.The effect of varying the "1" parameter of nozzles with a part circular entrance profile was examined and it was found that flow conditions approaching the ideal were obtained when the radius of curvature was between 0·40 and 0·550.

Jan 1, 1966

By M Coleman

Information is a key ingredient for successful mineral exploration and development. Whether identifying potential exploration localities from a map, interpreting technical reports or searching a register for operators past and present, the common aim is a parcel of information from which the enquirer can make a decision. Traditional information gathering often requires days or weeks of manual research, studying maps, files, reports etc, before consolidating the results into an investment proposal. In recent times, such methods have largely been replaced by Information Technology, making the process much faster, easier and more centralised. However, notwithstanding some very successful technology implementations, the general rush to computerise everything in sight has left many organisations struggling to cope with the management of large volumes of diverse information. Information management is now recognised as the most important factor in determining the success of information technology implementation. The Northern Territory Department of Mines and Energy (DME) has established a detailed information management strategy to underpin the rapid advance of computer technology within the organisation. A broad base of timely and reliable information is gradually becoming more accessible. It is envisaged that the availability of combined spatial, textual and scientific information will provide a sound basis for decision-making within the Department and the mining industry at large. Although information held by DME will be available at all times (24 hours on-line), its security and confidentiality will be guaranteed. The production of the DME system is aimed at satisfying the corporate objective to facilitate and promote mineral exploration and development. This paper outlines some current developments in the system.

Jan 1, 1994

By N Petropoulos and M J Thurley, E Righetti, M Wimmer

Fragmentation in sublevel caving (SLC) is vitally important. Both gravity flow and any downstream processes are affected. Reasonably coarse fragmentation may lead to larger draw bodies (isolated extraction zones) and hence potentially higher primary ore recovery and depressed/delayed waste rock inflow from above. Fewer flow disturbances are expected by mitigating oversize. In addition, it requires less boulder handling and reduces wear and possible hang-up problems in orepasses. To assess the present-day functionality of large-scale SLC, a multiyear, comprehensive measurement program was initiated. It covers the main elements for SLC, namely blast function, fragmentation and gravity flow. The present paper focuses on fragmentation measurements. An image acquisition system was used to document the drawpoint and the load-haul-dump (LHD) bucket for each mucking cycle. At the beginning, four buckets (about 70 t total) were sieved to validate the results of both 2D and 3D image analysis techniques. The fundamental and specific problems are discussed herein. At the moment, fragmentation of the SLC rings is evaluated using a quick rating system and a 2D fragment delineation software. The results enable a description of fragmentation and its variation during mucking but also – combined with the gravity flow measurements – conclusions on the fragmentation for different parts of the SLC ring. Possible influences on flow disturbances and ore recovery/dilution are investigated. The recent findings allow a better understanding of breakage and flow and support future process improvements.CITATION:Wimmer, M, Nordqvist, A, Righetti, E, Petropoulos, N and Thurley, M J, 2015. Analysis of rock fragmentation and its effect on gravity flow at the Kiruna sublevel caving mine, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 775–792 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By J Dwyer, M Hill

Downer’s mining division has made an operational and financial commitment to developing engineered solutions that mitigate the risks associated with operator proximity to uncontrolled development drill boom movements, and unguarded rotating drill steels.With the potential for serious injury or fatality, these identified risks are categorised as critical. Previous attempts by the industry to engineer them out have produced limited success, with numerous incidents still occurring year on year. Ultimately, the industry (as a whole) remains reliant on procedural prevention for operator safety.Downer understood the success of such an initiative would largely depend on the effective collaboration between operational experience, technology experts and automation. With so many variables requiring consideration; such as physical operator movement, machine boom movements, variable machine positions, and underground environmental impacts – challenging traditional technologies was necessary to deliver an optimal solution.For that reason, discrete detection (similar to laser curtains or beams) was considered not fit for purpose. The use of situational mapping, using rotating lasers, however, provided the optimal solution. The lasers collect data that is then processed using a custom software application.The software application is specifically programmed for tracking and classifying objects within detection zones, using advanced algorithms and filtering. Recognition and removal of non-positive disturbances are possible without losing personnel detection capability. The detection of relevant classified objects (humans) is determined by analysis of object size, age, movement, and speed etc. When the relevant object is detected, an alarm and inhibit function is applied preventing drilling functions.Any breach of the safety zone (forward of the front jacks) will automatically disable the hydraulic boom function. This can only be reset in the cabin once the person or persons have returned past the front jacks of the development drill into the safety zone.Downer, in collaboration with partner YUMARR Automation, has successfully developed this reliable boom isolation system, and is called JumboGuard. The system has now been commissioned and installed across all Downer Mining development drill fleets, operating in Australia.CITATION:Hill, M and Dwyer, J, 2017. JumboGuard – automatic boom isolation system, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 287–294 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By P F. Hodkiewicz

"Our understanding of mineral resources relies on three basic steps: data capture data interpretation model construction. Until recently, all three of these steps required significant time and manual effort to produce a single resource model for mine planning, typically taking more than a year to progress from drilling to the final block model. Over the past several years, BHP Billiton has been developing innovative workflows in rapid resource modelling projects to significantly reduce these time constraints and make the process more productive by replacing manual activities with automated ones. Rapid resource modelling is the process of combining recently developed off-the-shelf technology with internal technology developments to fundamentally change the way we collect, interpret, model and evaluate geoscience data. Initiatives include automated systems and standardised workflows to make it safer, faster and cheaper to continuously update multidiscipline resource models. Specifically, rapid resource modelling workflows combine: real-time analysis of drill holes and drill samples with downhole tools and hyperspectral scanning systemsautomated interpretation of drill hole intervals based on pattern-recognition algorithmscontinuous modelling workflows using implicit modelling software. This paper outlines technology developments and workflows that provide a more thorough understanding of mineral resources to support faster and more informed strategic, planning and production decisions.CITATION:Hodkiewicz, P F, 2014. Rapid resource modelling – a vision for faster and better mining decisions, in Proceedings Ninth International Mining Geology Conference 2014 , pp 183–188 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 18, 2014

By F N. Baez

This paper supplements a keynote address prepared for the MassMin 2016 conference on mass underground mining methods, including block, panel, inclined and sublevel caving. It advocates for a new cave mining paradigm that takes advantage of a number of new and disruptive technologies or innovations that have evolved over the last 15 years, some of which were initiated by major mining companies such as Codelco. The paper will address the challenges that the industry will be facing in the future as well as possible solutions. As background, the paper summarises the challenges that the industry has faced in the past and how such challenges were addressed. The author acknowledges that given his more than 30 years of experience with Codelco Chile (operations and corporate), aspects of his intelligent mining concept have no doubt been influenced and have matured during his invaluable time with Codelco also as the Head of Technology and Innovation. In the paper, he uses some of the innovations developed within Codelco and by the Chilean Government to illustrate the concept of ‘intelligent mining’.CITATION:Baez, F N, 2016. ‘Intelligent mining’ – the way of the future, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 3–8 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

A study of drilling data at various stages of development of an orebody show that the semi-variogram, used for calculating the accuracy of block estimates can be ill-defined if too few data are available. The consequencesin this case are to have blocks supposedly more accurately known than is possible at the early drilling stage; such a result being potentially dangerous. However, as the amount of data increases the recalculated, semi-variograms approach the underlying semi-variogram of the deposit and the calculations made using them become more reliable and robust.

Jan 1, 1977

By Pullen G, Rose M

Continuing Professional Development (CPD) is not just a catch-cry. It is an essential component of every-day life in many professions, including accountancy, law and public administration. Without realising it, many other professions are undertaking CPD activities in an un-structured way, including mining, metallurgy and geology. Examples include Annual and technical conferences of The Institute, Branch-level technical meetings and in-company training and development programmes and technical exchanges. Whilst approaches to date have undoubtedly helped keep the Australian mining industry at the forefront of mining technology, one cannot presume that technological development will stand still. To meet this challenge, human resource development must keep pace, not only to optimize utilization of technological developments, but more importantly to develop firm bases from which new products, processes and technologies can be developed within Australia.

Jan 1, 1989

By I Zh Bunin, V A. Chanturia, V G. Minenko, M V. Ryazantseva, A L. Samusev

A promising source for the extraction of rare metals and REEs in Russia is the eudialyte ores of the Lovozero deposit, which do not contain active uranium components. The eudialyte ore reserves of the Lovozero Massif are considered virtually unlimited and therefore have the potential to become a primary source of a number of rare and rare earth metals. The goal of this study was to comprehensively examine the effect of the parameters of high-power nanosecond electromagnetic pulses (HPEMP) and dielectric barrier discharge (DBD) on the leaching performance of eudialyte concentrate and the selective separation of zirconium and REEs from productive solutions. Using scanning electron microscopy and infrared spectroscopy, the mechanism behind the intensification of acidic dissolution of eudialyte as a result of pretreatment with energy impacts was described. During the HPEMP treatment, weakening and destruction of the eudialyte surface was observed, which at the substructural level is expressed in the deformation and local destruction of Si10O27, Si9MO30 resulting in formation of microcracks. During the DBD treatment, the formation of characteristic defects was observed in the form of imprints of dielectric breakdown microchannels and individual mineral fragments. Pretreatment of eudialyte concentrate using HPEMP made it possible to increase the recovery of zirconium into the pregnant solution of leaching by 3.4–4.3 per cent (from 86.6 per cent to 90.9 per cent) and by 4.1 per cent (from 86.6 per cent to 90.6 per cent) when using DBD. The increase in the total recovery of REEs was 1.2–1.8 per cent (from 87.7 per cent to 89.2 per cent). The effect of pH values, solution temperature, initial concentrations of valuable components on the successive recovery performance of zirconium and REEs from the pregnant solutions nitric from the acid leaching of eudialyte concentrate by chemical precipitation was examined. The possibility of selective separation of the zirconium product and rare earth elements with a zirconium recovery of 99.95 per cent and a REE recovery of 87.5 per cent was established. REE loss with the zirconium product was 8.0 per cent and 4.5 per cent with the spent pregnant solution.

Aug 24, 2022

By T Graham

The invention of the traditional belt and idler conveyor system is attributed to Thomas Robins in 1892. This basic concept, ubiquitous in most mining operations, has not changed markedly in 125 years and still suffers from five forms of energy losses. Firstly, Wheeler, Roberts and Jones (2004) showed that indentation rolling losses, a consequence of the indentation a roller inflicts on the belt, consume 60 per cent of all energy. Secondly, Wheeler (2006) explained that bulk solid flexure resistance resulting from material interaction and movement absorbs 20 per cent. The remaining energy is lost by idler rotating resistance (5 per cent), belt flexure resistance (5 per cent) and secondary resistances (10 per cent).Traditional conveyor systems are continuous as opposed to batch systems, implying both positive and negative features. On one hand, continuous systems have high availability (available infers ‘ready to run’), but, on the other, utilisation of availability is often low; for example, when a conveyor is running empty or below capacity. This converts into reduced system OEE (overall effective efficiency). Many attempts have been made to mitigate energy losses and low OEE issues, including development of rail-based systems. The key drawbacks have been higher capital cost, low flexibility, poor availability and lack of market acceptance.A recent conceptual development known as the ‘autonomous rail conveyor’ (ARC) promises to address issues of energy loss and poor availability and provide increased flexibility by offering solutions for difficult applications. The ARC uses a series of interconnected skeletal bogies covered with a conventional conveyor belt as a load bed running on relocatable light rail. The bogeys have two axles, each driven by integrated variable speed-geared motor and brake systems, and are connected to previous/next bogeys by specialised couplers. Power is provided by a generator (located in a dedicated bogey) and ‘daisy chain’ plug in cables. Centralised redundant control is provided at a preferred point. Although the system is batch in nature, the number of carriages and trains is flexible, meaning that the system is effectively continuous. Loading is achieved by feeding the ARC from a perpendicularly oriented apron feeder, while material off-loading is accomplished by a twist-dump operation in which the belt is twisted through an angle of 50° below the horizontal, causing material to flow from the belt into a receiving conveyor.The ARC system can run multiple trains over any distance, although benefits are more significant in distances of over two kilometres. Capital and operating costs are predicted to be lower than competitive products, with planned maintenance being simple to perform.CITATION:Graham, T, 2017. The autonomous rail conveyor significantly reduces ore haulage costs, in Proceedings Iron Ore 2017, pp 467–472 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By G Brooks

The control of phosphorus in steelmaking is one of the famous challenges of pyrometallurgy. It is well established that highly basic slags, the presence of FeO in the slag and lower temperatures (less than 1650°C) are favourable for phosphorous removal. The thermodynamics of this reaction have been extensively studied under laboratory conditions and the general trends confirmed through industrial trials. However, in general, phosphorus slag/metal distributions measured in industry are far from equilibrium and quite specific to the oxygen steelmaking technology being used. This variability was quantified by Urban, Weinberg and Cappel (2015), who found that the phosphorus partition ratio measured in plants varied with blowing practice, stirring intensity and even converter life. Some recent kinetic studies by Gu, Dogan and Coley (2017) have shown how the kinetics of these reactions vary with FeO content and dissolved sulfur at the droplet scale. A global kinetic model by Rout et al (2018) provides meaningful predictions of where dephosphorisation occurs in an industrial basic oxygen furnace (BOF) and some recent heat transfer modelling by Madhavan et al (2021, 2022) implies that temperature difference between droplets and slag has a role to play in explaining why equilibrium is not achieved. This paper will review the current state of knowledge and provide suggestions on predicting phosphorous removal for industrial operations and how greater removal could be achieved.

Jun 19, 2024

Tin mineralization in both eastern and western Tasmania shows a spatial correlation with middle Palaeozoic biotite granites and adamellites. The range of composition of these granitic rocks is restricted with respect to Mg, K, and Na content. Because this compositional restriction is shown by granitic rocks from other tin provinces, the concept of a genetic relationship between these granites and the associated tin mineralization is reinforced, and similar concentration mechanisms may be involved.Gold mineralization is largely restricted to eastern Tasmania and in contrast to the tin mineralization is rarely spatially associated with the middle Palaeozoic granitic rocks, although most authors have suggested a genetic correlation with hornblende and/or biotite granodiorites.Although few analyses are available, the granodiorites that are spatially associated with gold deposits exhibit similarities to granitic rocks from gold provinces elsewhere. These features suggest a possible genetic relationship between gold mineralization and the granodiorites.The composition of granitic rocks may be used as an aid to exploration in delineating areas of potential tin and gold mineralization in granite terrains.

Jan 1, 1970