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By Barro L

There is currently a world wide interest in coal-oil technology as the search continues for alternative energy sources to reduce the consumption of petroleum crude. An important aspect of this coal-oil technology study is to obtain information on the flow properties of coal-oil slurries. While some work has been reported on the flow behaviour of black coal-oil suspensions, very little work on brown coal-oil suspensions has been reported. In this paper flow charac- teristics of brown coal-oil suspensions for various coal concentration and temperatures have been presented. A Capillary rheometer, designed to handle settling suspension, has been used for deter- mining rheological properties. Brown coal of 0 0725 mm average particle diameter has been used in this work. The oil was a coal derived product having a boiling point range of 234¦- 319¦C, Apparent viscosity of all suspensions was found to increase on storage due to ageing. Ageing might have occurred due to physico- chemical interactions between coal and oil. Flow behaviour of some suspensions changed from Newtonian to non-Newtonian on storage.

Jan 1, 1980

By D Kepert

It is the role of the exploration geologist to create wealth through the discovery, delineation and characterisation of economic mineralisation. This requires a critical depth of geological understanding.Unfortunately, the resource industry is well known for its cyclic nature. Many of the current generation of workers have only ever experienced the boom of the ‘super-cycle’ and are only just discovering the negative side to the business. For the case of the geologist and especially the exploration geologist, the magnitude of peaks and troughs are usually amplified and may become destructive to all parties. During the uptime a healthy stream of exploration good news becomes the staple diet of company releases, in particular those of junior companies attempting to bolster the share price. The geological knowledge and experience gained thus forms a significant and integral part of the value and therefore, future of a company. On the downturn it is often viewed that geologists are a luxury, an optional extra and a burden on the bottom line with companies entering a period of memory loss and myopia.Retention of geological knowledge however remains critical as projects, companies and cycles mature. Beyond exploration per se, this knowledge becomes both fundamental in de-risking and commercialising an asset (through development or divestment) and in positioning the company for cyclic or counter-cyclic opportunities.The growth and retention of this knowledge base is difficult to quantify in terms of direct value but becomes one of a successful resource companies greatest assets. At worst, its loss can lead to millions of investors’ funds wasted on missed opportunities, drilling, or poorly designed plant and mine.But the rocks are around for the longer haul and pay little notice to the vagaries of the scurrying of Man.This paper reflects on some of the authors own observations through 25 years of iron ore exploration, in why it is critical to always rigorously question the prevailing geological (mis)understanding and the technical and commercial benefits which that may bring, and looks forward to the future.CITATION:Kepert, D, 2015. Geology – the affirmative case, in Proceedings Iron Ore 2015, pp 285–298 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By A Parbhakar-Fox, S C. Dominy

The prediction of acid and metalliferous drainage (AMD) from mine waste materials is critically important during all stages of the mine value chain. However, to determine such geoenvironmental characteristics static and kinetic testing of individual waste units must be performed on representative samples. The importance of sample selection cannot be underestimated; it is the single most critical aspect of any geoenvironmental investigation. Poor sampling techniques and inadequate sample selection will contribute to excessive variance, difficulties in interpretation and incorrect assessment. By undertaking mesotextural characterisation based on hyperspectral mineralogical data (with sulfur assay data if available), opportunities to improve sampling strategies are presented. Such data will inform the selection of samples for low-cost total sulfur, paste pH and geoenvironmental logging, which collectively will allow for accurate AMD forecasting and improved sampling practices to be achieved. Once sampled, robust quality assurance/quality control (QA/QC) protocols must be developed where the use of international certified reference standards become obligatory. This is currently not practised, resulting in inter-laboratory discrepancies when undertaking waste classification. Further improvements in geoenvironmental characterisation testing lies in the adoption of blended static testing protocols, whereby blends of waste materials can be efficiently tested so as to give an early forecast as to whether they will produce acidic or metal-laden drainage. Such information is integral in developing a waste schedule that will allow for a non-acid forming waste landform to be constructed right from the start of the operational phase. Ultimately, improvements in this discipline lie in technological innovations with regards to mineralogical characterisation, and by offering geoscience and minerals engineering students a competent education in the discipline. Collectively, this will empower a step-change in AMD prediction and waste handling, and will make the realisation of the United Nations Sustainable Development Goals a reality, rather than a dream.CITATION:Parbhakar-Fox, A and Dominy, S C, 2017. Sampling and blending in geoenvironmental campaigns – current practice and future opportunities, in Proceedings Eighth World Conference on Sampling and Blending , pp 45–54 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By C Smith, R I. Maczkowiack, P D. Erskine

Open cut coal-mining has been conducted in the Bowen Basin region of central Queensland for almost five decades, and has disturbed an estimated area of 140 000 ha of agricultural land until 2011. Approximately one-third of the area disturbed by mining has been rehabilitated to pastures or bushland. However, none of the rehabilitated land has yet been assigned a specific end-use. This research project develops an approach for assessing end-use risks for the regionÆs mined land, and develops risk assessment models for selected end-uses. First, a web-based survey of stakeholders was used to identify risks to be assessed. The risks identified were surface erosion, subsurface erosion, bushfires, weeds and feral animals. The survey also identified possible end-uses of bushland and grazing. Second, conceptual risk models were developed based on the risk assessment concepts of likelihood and consequence specified in the Australian and New Zealand risk assessment standards. Likelihood was modelled using site characteristics and management factors that influence the occurrence probability of risks (eg surface erosion), while consequence was modelled using a set of site condition indicators and condition thresholds (changes in root-zone water-holding capacity, soil erodibility, vegetation ground cover and soil organic matter and transition probability to a non-preferred ecosystem type).The factors influencing likelihood and consequence for each risk have been integrated using Bayesian networks. The next step in model development is to parameterise the Bayesian networks using existing equations, empirical datasets, or expert opinion where data are not available. The parameterised models will be used to assess grazing and bushland end-uses against erosion, bushfire, weed and feral animal risks for rehabilitated mined land sites, with the purpose of identifying the relative risks associated with each end-use, and the landform design specifications and land management practices under which end-use risks are minimised.CITATION:Maczkowiack, R I, Smith, C and Erskine, P D, 2012. Risk assessment models for post-mining land use, in Proceedings Life-of-Mine 2012, pp 33-42 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By C Jenkins, M Mativenga, C Stanton, J Gerber

In 2014, Arrium completed an optimisation program on its magnetite concentrator, enabling a reduction in the overall cost base of producing concentrate through an increased ability to treat a wider range of ore types, previously considered waste. The development was the culmination of four years of work, conducted in house by Arrium’s mining development group. The overall intent of the plant design focused on improving the concentrator’s ability to treat a wider range of magnetite ore types. Metallurgical analysis of these feed ore groups outlined a need for more grinding power if production quality was to be maintained and throughput increased. As such, a tertiary grinding circuit was designed which, alongside the rectification of key operational bottlenecks, would allow the plant to continue to produce concentrate at the required specification and rate. The technology chosen for the tertiary grinding application was the XT IsaMillTM, which is known for efficient fine grinding when compared to conventional ball milling. The transfer sizes between the existing comminution circuits were coarsened, allowed for the treatment of different ores at the required rates. The optimisation project was successfully completed in February 2014 after a three month commissioning phase. The initial metallurgical testing and engineering of new equipment proved highly successful with all equipment meeting or exceeding design parameters.CITATION:Stanton, C, Mativenga, M, Gerber, J and Jenkins, C, 2015. Unlocking plant capability through targeted debottlenecking of Arrium’s magnetite concentrator, in Proceedings Iron Ore 2015, pp 185–190 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By B Twidle, D Bertoldi, J Meikle, R Dunne

The Waihi Gold Mine is situated in a high rainfall area (annual average of over 2 m) on the North Island of New Zealand. Water treatment and discharge at the mine has been ongoing for the last 25 years. The first water treatment plant consisted of a æstandardÆ water treatment facility (ferric chloride precipitation) and cyanide detoxification. With time the project has expanded and the volumes of water increased requiring additional treatment methods (reverse osmosis) to meet the water quality for discharge. This paper will provide information on the historical development of the water treatment flow sheets, performance data and operating costs.CITATION:Bertoldi, D, Dunne, R, Twidle, B and Meikle, J, 2013. Water treatment at the Waihi Gold Mine, in Proceedings World Gold 2013 , pp 503-508 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By K W. Mills, N R. P Baczynski, J Mylvaganam, D A. Prado, M F. Lee, I A. de Bruyn

"This paper presents the second part of a study of the assessment of rock stress inputs on the performance of various new mining designs at the Ok Tedi large open pit mine in Papua New Guinea. Over the years, four programs of rock stress measurement have been completed at Ok Tedi, each providing different interpretations of the in situ field stresses. Details of three of these programs and interpretations are provided in the precursor to this paper, entitled ‘Rock Stresses at Ok Tedi, Papua New Guinea’ (Lee et al, 2014).This paper explains how the various stress interpretations were utilised in the modelling of the proposed new open pit and underground mining excavations, comparing where possible their expected effects on stability. The modelled performance of three specific mine components have been discussed here as case studies, including: the below-pit drainage tunnel, as the floor of the open pit workings is mined down from 350?m above, to within just 75?m above the crown of the tunnel the stability of the 1000?m high slope of the proposed West Wall cutback the proposed sublevel open stoping extraction sequence in the Gold Coast orebody beneath the East Wall, for which only the likely ‘worst-case’ stress regime was used to assess sequencing and stability issues.The benefits of scheduling the collection of detailed rock stress measurements and other input data from a range of different sources at various stages of the projects are discussed.Alternative in situ stress models have less stability impact on open pit slopes than on underground mine excavations.CITATION:de Bruyn, I A, Baczynski, N R P, Lee, M F, Mills, K W, Mylvaganam, J, and Prado, D A, 2014. The application of rock stress inputs to stability assessments at Ok Tedi Mine, Papua New Guinea, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference, pp 43–54 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 5, 2014

The Newmont Waihi Operations are centred on the Martha mine at Waihi, New Zealand. The mine has produced over 6.6 million ounces of gold from both openpit and underground sources since operations began in 1878. The current open pit operations commenced in 1988 and in the year to 30 June 2002 produced 129,790 ounces of gold at a cash cost of USD122 per ounce. This paper provides an overview of current operations and future directions.

Jan 1, 2002

By Y Cui, G Cao, H Zong, J Zheng, J Wang, S Yue, J Zhao, B Li

The iron (Fe) concentration in nickel slag is high, making its recovery and utilisation a hot and challenging topic. In the nickel smelting process, using CaO instead of SiO2 to adjust slag’s composition, and then directly reducing Fe from the output of molten slag is a more feasible method in practice for Fe recovery in nickel slag. The adjustment of slag’s composition in the nickel smelting process will have an impact on the distribution of impurity elements such as Pb, Zn, and As. In this paper, the slag adjustment of nickel smelting process was carried out with the oxygen-enriched topblowing system. The distribution of impurity elements in the smelting products with each composition slag was conducted by using thermodynamic software. Experimental verification was performed with rich oxygen top-blowing, and the distribution characteristics of impurity elements in the smelting products were characterised to explore the differences in mineral phases of impurity elements with each smelting conditions, elucidating the distribution patterns of Pb, Zn, and As in each phase. The results indicate that after slag adjustment, impurity elements are more easily to volatilisation and removal into the gas, reducing their total concentration in slag and matte. In the slag, the existence form of Pb, Zn is changed from silicate to ferrate, and As is changed from arsenate to low-valent arsenic oxide. It is easier to decompose the impurity-containing mineral phase and remove the impurity elements in the subsequent iron extraction process.

Jun 19, 2024

By Jansen N

Production from the narrow, high grade silver-lead-zinc orebodies below 15 level commenced in mid 1985.Geological, mining research and recent mining experience determined that a mechanised drill, fire and muck cycle would be the most suitable method.Ground conditions are predicted to be worse than in other cut and fill (MICAF) areas at Isa Mine, owing to the increased depth, more variable dip of the orebodies and the increased effect of major geological structures.Mechanised ground support and tight filling techniques feature in controlling these expected adverse ground conditions.

Jan 1, 1985

By B C. Povey, K Lagutin, M Mryasov, V Noll

The current Stoilensky magnetite concentrator comprises a three-stage crushing circuit followed by three stages of ball milling, grinding and concentration to produce a magnetite concentrate with 66.5% iron (Fe). The plant is built in four lines, three lines having four mills and one line with five mills, to treat 32 Mt/y of ore and produce 13.9 Mt/y of concentrate.NLMK, the owner, is Russia’s third largest steel maker and while the ore from the Stoilensky Mining and Beneficiation Plant (SGOK) provides the bulk of their supply, they still must buy ore from external sources at world prices. A decision was taken to expand the SGOK operation to supply all the NLMK concentrate, including the production of pellets.To commence the expansion, high pressure grinding rolls (HPGRs) were introduced as a fourth stage of crushing ahead of the first ball mill. This was a relatively low capital cost expansion and increased production by 12 to 15%, the cost being much less than an additional grinding line. The importance of this development was that earlier introductions of HPGRs in Russia had presented several problems so there was some reluctance to the initial concept. The even greater significance was that nearly every magnetite plant in Russia had a three-stage crushing circuit so the successful introduction of HPGRs was of interest to many operators.The design was developed by a team, consisting of Worley Parson, Mineralconsult and PiterGORproject (PGP), for the first four units to fit inside existing building structures. The first two units were commissioned in March 2016 and the next two units in May 2016, and production improved by over 12%. The design of the installation of the final four units is in progress and the installation is expected in late 2017.CITATION:Povey, B C, Noll, V, Lagutin, K and Mryasov, M, 2017. Introducing HPGR quaternary crushers in a Russian magnetite operation – challenges and solutions, in Proceedings MetPlant 2017, pp 84–100 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

Lateritic nickel ore occurs as a supergene or residual deposit as a result of the tropical weathering of underlying ultramafic rocks. The mineralisation may be as hydrated Ni-Mg silicates, like garnierite (silicate ore); or as hydrated Ni-Fe oxide (oxide) ore. Non-sulphide ore represents only 30% of the tonnage mined, but represents 85% of the total world's nickel reserves. A typical lateritic profile consists of 4 zones above the unweathered ultramafic parent rock: Zone 1: the "upper laterite" which is dark red-brown, porous and concentrically structured. It contains 0.2 to 0.8% Ni, 48.0 to 72.0% Fe, and 0 to 9.5% MgO. It is often capped by a ferricrete crust. Zone 2: the "middle laterite", which is red-brown to light brown and more porous than the above zone. It contains 0.8 to 1.5% Ni, 42.0 to 48.0% Fe and 0.5 to 6.0% MgO. Zone 3: the "basal laterite" which is yellow-brown to yellow-orange,

Jan 1, 1974

By G Burton, S Fityus, J Li, S Vaughan, D Payne

Daunia and Caval Ridge coal mines, owned and operated by BHP, have been co-disposing rejects and dewatered tailings within spoil dumps from the beginning of their operations in 2013 and 2014, with the purpose of minimising environmental impact and geotechnical risk. Following the recent large failures of tailings dams around the world, BHP Coal, through its Coal Tailings Program, plans to transition other coal mines to deliver “dry” tailings and produce mixed plant rejects (MPR) for inpit co-disposal. This will materially reduce future tailings dam risk exposure. Previous laboratory shear strength testing was conducted on rejects with a maximum particles size of 20 mm, and some concerns were raised that this might not represent the mechanical properties of the actual full particle size distribution (PSD) rejects. BHP was also aware that using different technologies to dewater the tailings, such as belt press filters (BPF) and solid bowl centrifuge (SBC), could produce thickened tailings which could significantly modify the physical behaviours of the MPRs, particularly the bonding between particles. Therefore, laboratory testing on both coarse rejects and mixtures of the coarse rejects and dewatered tailings (MPRs), with full PSDs, was carried out. Testing was performed using the large direct shear machine developed by the Australian Coal Association Research Program (ACARP) project C20019 in 2017, as well as a 300 mm diameter triaxial apparatus at the University of Newcastle (UoN). This paper presents details of the laboratory testing program and results for the rejects from the first studied mine of the BHP Coal Tailings Program. It compares the shear strengths measured at full scale with those tested on modified (scalped or crushed) specimens in the past; and discusses the tailings dewatering technique selection from geotechnical aspects based on the testing results, and finally presents some dump and tip head stability analysis results using the testing results.

Jul 1, 2021

By H Law, M Muller

Mount Isa Mines (MIM) Copper Concentrator currently utilises Agitair 120 banks for its roughing flotation circuit. Apart from a rotor change, the only other significant work completed to the Agitair banks since their installation and commissioning over 40 years ago has been a like for like refurbishment in 2016. The Agitair banks at the MIM Copper Concentrator currently utilise the Pipsa rotor design which progressively replaced the original Chile X rotor design in the 1980’s and 90’s in the copper concentrator. Since the development of the Pipsa rotors, modern rotors such as the Dorr-Oliver (DO) high shear rotors have been released to the market with proven recovery and concentrate grade improvements over previous rotor designs. This paper aims to detail the installation, testing and comparison of Pipsa versus Dorr-Oliver rotors in two different flotation sections of the MIM Copper Concentrator.CITATION:Muller, M and Law, H, 2018. High shear rotor trials in the Mount Isa Mines Copper Concentrator, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 393–402 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By M Barden, G Lane, B Quilliam

NQ Minerals PLC, through Hellyer Gold Mines Pty Ltd, plans to reprocess the contents of the Hellyer tailings dam to produce lead/silver concentrate, zinc concentrate and pyrite concentrate (containing Au and Ag). This paper discusses the project development, mineralogy, metallurgy and chemistry of processing Hellyer tailings and the associated environmental benefits. The Hellyer and Fossey orebodies were volcanic hosted polymetallic massive sulphide deposits located within the Mount Read volcanic arc of western Tasmania. Mineralisation was hosted in massive sulphide (pyrite) and comprised predominantly of sphalerite, with lesser galena, chalcopyrite and arsenopyrite. The Hellyer orebody was mineralogically complex (fine grained) and was treated through differential flotation with initially modest recoveries. Fossey ore processing characteristics were similar to those of Que River ore and simpler than Hellyer but treatment still resulted in significant grades in flotation tailings. CITATION: Lane, G, Barden, M and Quilliam, B, 2018. Hellyer tailings – complex mineralogy but higher grade than many ore bodies, in Proceedings Complex Orebodies Conference 2018, pp 35–38 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Hughes J. C

THE smelting plant consists of five large furnaces operating in the treatment of current flintered material, and one small furnace operating periodically in the treatment of copper dross and antimonial slag produced in the lead-refining process.he following table supplies the leading dimensions and details of the large furnaces:-(a) Crucible - Dimensions 17 ft. 2 in. long x 4 ft. wide x 2 ft. 3 in deep. Capacity - 30 tons lead. Class of lining - firebrick. No. firebricks required - 3000.(b) Crucible Tank - Dimensions 20 ft. 6in. long x 10 it. 6 in. Wide x 4 ft. 3 in. deep. Material - 1/2 in. mild steel.(0) Jackets - Dimensions 6 ft. long x 19 in. wide x 6in. thick. Material - Cast-iron. Average life - 2 years. Number per side - 11, with 13-in. bosh. Number per end - 3, with 9-in. bosh.

Jan 1, 1922

The current genesis of pisolites and channel iron deposits (CID) has been defined in a way that presents CID as unique in the world. The published material on detrital pisolites mostly details the West Australian CID; most other global occurrences of iron-rich pisolites would seem to have an in situ genesis. An alternate theory for the origin of the Hamersley CID is suggested, involving an older greensand protore derived from volcanic ash and deposited on a glaciated Hamersley surface. This paper presents the author's observations, sampling and mapping after several years study and exploration for pisolites and CID in WA and in some locations overseas. It is not what one would call scientifically complete, and possibly asks more questions than it answers, but it is presented as a point for discussion.

Jan 1, 2009

By P Mikula, B Darlington, J Graham, P Young

In underground mines experiencing dynamic events, there is an ever-present challenge to design and maintain a capable ground support system. One key component of ground support systems is surface support, which serves the essential roles of retaining failed rock and transferring forces generated by surface displacement to rock bolts or other support elements. Observations underground show that in many instances, standard mesh panels alone do not provide sufficient dynamic support to retain substantial bulking failures imposing displacement onto mesh, and in such cases Mesh straps and W-straps may be employed. Determining the performance of surface support elements proves to be difficult, with a multitude of variables at play in the underground environment. Quite comprehensive work has been completed on laboratory testing of surface support systems; however, very little work has been conducted on in situ dynamic testing of Mesh straps and W-straps. In 2019 in Western Area’s Flying Fox Mine, in situ dynamic testing was conducted on a series of Mesh straps and W-straps using Sandvik’s in situ Dynamic Test Rig (DTR). The testing regime applied impact energies from 5.1 to 15.3 kJ to Mesh straps and W-straps. The performance of the straps that did not fail was a maximum absorbed energy of 9.3 kJ and 14.2 kJ for the Mesh straps and W-straps respectively. The testing successfully demonstrated the ability of Sandvik’s DTR to test not only rock bolts, but also surface support elements, creating new testing and research possibilities. The testing also provided important design guidance data that is not practicable to obtain using laboratory dynamic testing facilities.

Nov 29, 2022

By M I. Pownceby, M A. Rhamdhani, D M. Fellicia, S Palanisamy, R Z. Mukhlis

The trend of global copper production has prospectively increased over time. Based on typical mined ore grades, 1 t of copper ore generates approximately 6–10 kg of copper, which requires much energy, usually in the form of metallurgical coke. Copper production using carbon as a fuel and reductant contributes up to 0.3 per cent to global greenhouse gas (GHG) emissions. As a result, research into decarbonisation processes applicable to reducing low-grade copper sulfide ores, copper oxides, electronic wastes and other alternative complex Cu-rich materials has increased. Alternative fuels for reducing carbon-rich emissions in pyrometallurgical copper processing include methane, ammonia, biomass, solar and wind power, but in recent times increased focus has been on hydrogen as a potential fuel and reducing agent for materials such as oxidised copper scrap, Cu2O/CuO and Cu-rich slags/e-wastes. From a thermodynamic perspective, hydrogen exhibits a significantly more negative standard Gibbs free energy (ΔG°) than copper oxide making it a suitable reductant and the exothermic thermal effect from reaction between hydrogen and Cu2O/CuO may be used to control process parameters. These characteristics renders hydrogen an ideal gas for reducing copper oxides and copper-containing slags/e-wastes. This review article assesses previous research on utilising hydrogen for producing and refining copper from primary and secondary feed materials.

Jun 19, 2024

By T C. Westerfield, G, M J. Mankosa

An innovative separator known as the HydroFloat cell has been developed specifically for the upgrading of coarse particles that are difficult to recover using conventional flotation cells. The novel characteristic of this separator is the formation of a hindered teeter-bed of fluidised solids into which small air bubbles are injected. The air bubbles selectively attach to hydrophobic particles and form particle/bubble agglomerates that segregate atop the teeter-bed due to their lower apparent specific gravity. The low-density agglomerates are eventually carried into the product overflow launder by the rising current of teeter water. Hydrophilic particles remain in the teeter-bed and are discharged to underflow as a high solids content tailing. Benefits of this hybrid flotation-density separator include enhanced bubble-particle contacting, increased particle residence time, and very low air demand. Test data indicate that significant improvements in the recovery of coarse particles can be achieved using this innovative technology. This article describes the theoretical basis for the development of the HydroFloat cell and provides an overview of recent pilot-scale tests conducted for the phosphate industry.

Jan 1, 2005