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By Nakahiro Y, Wakamatsu T

In the present study, from experimental results, a new concept of possibility of flotation separation of quartz from feldspar is presented. The effect of the nonionic surfactant Brij 58 on the flotation behaviour of quartz and feldspar has been investigated. The effect of the surfactant adsorption at the solid-liquid interface was also studied. The results demonstrate that maximum flotability of quartz occurred at low concentration of surfactant. Feldspar is not collected by this surfactant. Flotation tests with feldspar that had previously been subjected to leaching by hydrochloric acid yielded similar flotation response as that of quartz. The effect of removal of alkali cations from feldspar surface on its flotability was investigated. The effects of inorganic and organic additives on the flotation recovery of quartz are discussed in terms of the slating-out or salting-in properties of these additives. KEYWORDS: Alkyl polyoxyethylene; feldspar; flotation; nonionic surfactant; quartz; salting-in; salting-out; separation; silanol groups.

Jan 1, 1993

By M Lak, R Amiri, A Haratian, M Asghari, S Haji

Dry magnet separators are used to upgrade and beneficiate a wide variety of minerals such as hematite and magnetite materials. In recent years advances in dry magnetic separators have improved their performance. Fine particle separation is one of the main areas which still remain weak. This paper will present a new design of fine particle drum separators which used for particle size less than 3 mm. A big problem in processing of iron ore is the grade and recovery of mineral values in the fines fraction. The new design high efficiency drum separator is developed to handle fine feeds. In this drum separators both of the drum shell and magnetic yoke rotate in opposite direction. the results showed that when the material feed size was = 1298 μm, drum shell speed was 42.5 rev/min, magnetic yoke speed was 100 rev/min and the maximum intensity of magnetic field was at = 30° the feed grade increased from 50.87 to 65.67 in concentrate box, increase to 60.45 in middle box and tail grade was 24.44. The total achieved recovery for both concentrate and middle box was 81.89 per cent.

Nov 8, 2021

By L Manca, P B. Hills, D Tyler, N Pollington

This paper describes a collaborative project undertaken by Newcrest Mining Limited (Newcrest) and pitt&sherry to identify, develop and then implement global best practices to manage the exposure to inrush (dry and mud) hazards in underground mining operations. An extensive literature review was undertaken to identify past experience globally and the current state of knowledge and practice in managing inrush hazard. A key requirement of the literature review was the development of a list of guiding questions which would form a framework for approaching operators to discuss the topic, capture recent learnings and understand current operating practices to allow the development of a best practice solution. An initial cohort of 14 mines across four continents chose to contribute and detailed interviews were carried out by the project team. The outcome from the literature review, interviews with participating mines and various internal discussions was a comprehensive summary document detailing Basic versus Best Practice management of the inrush hazard. This document is being used as a gap analysis tool by Newcrest to assess and guide the management of inrush hazard at their existing and future operations. The summary document has also been provided to the participating mines for their consideration. The project is iterative and will continue to evolve as new experiences, knowledge and practices come to light.

Mar 15, 2021

By M S. Reston

The Tonkolili banded iron formations (BIF), Sierra Leone, host extensive iron ore deposits which are of economic signifi cance to the seaborne iron ore trade. The deposits are dominated by a strategic JORC compliant mineral resource of 11.6 Bt grading 30.1 per cent Fe comprised of primary magnetite mineralisation in the form of a fresh metamorphosed BIF featuring a uniform mineral assemblage of quartz-magnetite ± ferro-silicate minerals. Pilot plant metallurgical test work has demonstrated that the production of a magnetite concentrate is achievable using the established beneficiation techniques of magnetic separation and flotation. The concentrates arehigh-grade, and suitable for blast furnace or direct reduced iron pellet feed. The major challenge facing the development of such magnetite deposits at industry competitive production rates is the significant capital investment required for process plant and associated infrastructure.Two well-developed weathering zones exist within the deposits, and are associated with the progressive development of a tropical weathering profile overprinting the primary BIF. These zones feature a near surface hard indurated duricrust up to 60 m thick, and a soft progressively developed saprolite between duricrust and fresh BIF. These zones have been found to be amenable to producing iron ore products including DSO lump and sinter fines from the duricrust, and concentrate from the saprolite. Mineral resources sufficient to support commercial production of such iron ore products were defined by an intensive exploration program in 2010.African Minerals Limited has developed a three phase production strategy to progressively self fund the development of the Tonkolili strategic magnetite project by:• commencing a Phase I 12 Mt/a DSO operation in Quarter 4 2011,• increasing production in Phase II to 35 Mt/a with the commissioning of a saprolite beneficitation plant and associated infrastructure upgrades, and• developing a 45 Mt/a Phase III operation producing high-grade magnetite concentrate.The comparatively low capital and operating costs of a duricrust DSO lump and sinter fines operation coupled with its proximity to ground surface make it highly attractive for the generation of early cash flow for the Tonkolili project. Revenue from this early production may be used to selffund the subsequent development of phases requiring progressively more significant beneficiation plant and infrastructure.

Jul 11, 2011

By M Haest

This study demonstrates the application of HyLogging™ technologies for mineralogical characterisation of different iron ore types throughout the Hamersley Province (Western Australia), including a channel iron deposit (Murchison Metals Ltd) and bedded iron deposits in the Brockman and Marra Mamba Iron Formations (BHP Billiton Ltd).Drill core from these deposits was analysed using CSIRO’s hyperspectral drill core logging systems (HyLogging systems), which are commercially available at the AMDEL and AMMTEC laboratories in Perth (Western Australia), through a leasing agreement. These HyLogging systems provide high resolution photographs at 0.1 mm pixel resolution as well as visible and infrared spectroscopic refl ectance data at 1 cm spatial resolution. The minerals identified include haematite, goethite and its subtypes (ie vitreous and ochreous goethite), AlOH-clays (kaolinite, Al-smectite and white mica), carbonates, gibbsite, chlorite, amphibole and hydrated silica as well as water content. The abundance and composition of these minerals was established from the spectral data and was validated against XRF analyses.The full potential of HyLogging systems in the iron ore industry is only starting to be unveiled, but some major benefits have already been demonstrated:• HyLogging systems can delineate different ore zones by mapping the vitreous and ochreous goethites. This has a potentially large impact in mine planning and operations, as hard, vitreous goethite and soft, powdery, ochreous goethite have different processing characteristics that can affect plant throughput if not carefully managed.• HyLogging mineralogy can also be used to support stratigraphic interpretations of the host, for example in subdividing the Dales Gorge 1 - 4 submembers of the Brockman Iron Formation.• HyLogging can have a potentially signifi cant impact on waste rock characterisation, as many of the waste materials can be identifi ed and quantifi ed with hyperspectral data (eg clay-type,• hydration state).• HyLogging can provide accurate three-dimensional (3D) mineralogy to iron ore companies that will empower them to improve future exploration and resource planning.• Application of high resolution photography to further improve ore deposit domaining is also to be considered.

Jul 11, 2011

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 A S. Fogliata, L Bengochea, G Mas, J E. Lazarte

The Culampajß auriferous district is located in the northern sector of the eastern edge of the homonymous hill, Catamarca Province, Argentina. Tajo Largo mine is situated in the southern flank of Las Minas gulch at an approximate height of 3.600 m above sea level. In the studied area main outcrops are orthogneiss rocks of Chango Real Formation. The ore mineral is native gold with a lesser amount of pyrite, chalcopyrite, haematite, limonite, malachite, azurite and covellite. These ore mineral assemblages are disseminated in quartz veins filling tension fractures in the host orthogneiss.Several types of inclusions have been recognised, including three phase H2O-CO2liq-CO2vap inclusions, polyphase inclusions with H2O-CO2 and one or more solid phases, and two phase aqueous inclusions. In the three phase H2O-CO2liq-CO2vap inclusions the Tmclath is about 1¦C and the CO2 liquid-vapour homogenisation occurs at 26 - 28¦C, to liquid phase. The homogenisation temperature of H2O-CO2 occurs at 365 - 380¦C in the aqueous phase. This set of data defined a solution with a salinity of 14, 4 wt per cent NaCl equivalent and a density of 0.84 g/cm3. In the two phase aqueous inclusions the melting temperature (Tm) of -5.4¦C and the eutectic point (Te) in -38¦C indicates a salinity of about 7.5 wt per cent NaCl equivalent, with the probable presence of Ca2+. Density of fluid is about 0.83 g/cm3. Homogenisation temperature ranges between 260¦ and 280¦C. The pressure, temperature and salinity of fluids in the polyphase inclusions suggest an early fluid of high density and high salinity. The three-phase fluid inclusions may be the result of an unmixing-phase separation of post magmatic hydrothermal fluid due to pressure decrease along fractures. It is suggested that the deposit was formed during the late magmatic hydrothermal stage genetically linked to granitic rocks and can be comparable with the intrusion-related gold system of Baker (2003).

Jan 1, 2008

By P Thompson, B W. Atkinson

Water treatment is not æcore businessÆ for mining companies.Just as mineral ores and coals are unique, each requiring detailed characterisation and pilot-testing to determine their optimum beneficiation route, so too are mine waters, each requiring careful assessment to determine the most appropriate treatment. There are many cases of æregret capitalÆ expenditure, whereby mines have installed off-the-shelf equipment only to find it inadequate for their purposes or grossly expensive and labour intensive to operate.Water may be required for potable purposes, ore processing, dust control and/or irrigation. A major driver will frequently be environmental constraints for off-site discharge. Mine water projects can become very complex, and detailed models need to be prepared and optimised to properly consider the raw water sources, the on-site storages, the on-site uses and the off-site discharges, as well as handling the residuals (by-products) of water treatment. By-products may be in the form of concentrated backwash streams or streams of elevated salt content. Careful management of the by-products is required to avoid recontamination of the source water.Regulators often drive mine owners toward reverse osmosis (RO) so that their discharges can be considered as æzero dischargeÆ in terms of potential pollutants. Such decisions need to be based on site-specific information rather than any form of æblanketÆ requirement. An analogy is that many humans like to consume mineral water rather than ænormalÆ tap water. Receiving environments also accommodate or even prefer their æmineralsÆ and so RO is neither warranted nor sustainable in many cases.This paper presents two case studies for operating mine sites, both of which have a significant excess of water requiring environmental discharge. The examples demonstrate a sensible balance between treatment type, environmental constraints, process implementation and residuals management. LIMN« æthe flow sheet processorÆ was used to model one of the case studies due to the complexity of the water system on that site.CITATION:Atkinson, B W and Thompson, P, 2013. Mine water - optimising for site and environment, in Proceedings Water in Mining 2013 , pp 9-14 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By M Weeks

Melbourne Water Corporation, through the Pipelines Alliance, has commenced construction of a new drainage pipeline to provide additional flood protection within the Sandgate Avenue Main Drain catchment, in order to mitigate against the risk of flooding of Frankston’s central activity district (CAD).The project involves the construction of a 1550 m long, 2.5 m internal diameter tunnel, commencing upstream at the Monash University Peninsula Campus and traversing approximately west to the outlet located at Kananook Creek. The tunnel was excavated by a dual slurry-earth pressure balance tunnel boring machine (TBM), with the depth to tunnel crown ranging from 0.7 m to 14 m below the natural surface level. The TBM navigated 500 m radius curves, with a maximum drive length of 608 m. The tunnel lining consists of 2.5 m internal diameter, 250 mm thick reinforced concrete jacking pipe.The geotechnical conditions along the tunnel alignment consisted of mixed face ground conditions, predominately clay, with clayey sand and sandy clay and some sand deposits near Kananook Creek.This paper presents the challenges associated with the operation of the slurry separation plant during tunnel construction. In particular, the paper focuses the impact of slurry separation on tunnel advance rates, the lessons learnt during construction with regards to slurry separation and on the decision to adopt a dual slurry-earth pressure balance shield TBM. In addition this paper highlights the importance of having a thorough understanding of the slurry separation requirements on a slurry TBM project prior to selecting the necessary plant.

Mar 8, 2011

By T M. Brettell, D Sidea

The CSA Mine is located in Cobar, New South Wales and is operated by Glencore. Large scale underground production started from 1965, with zinc, lead, silver and copper extracted in the past. The current operations focus on copper, with a silver co-product.From 2014 to 2016, Cobar Management Pty Ltd (CMPL) undertook a major capital project to upgrade the primary ventilation system at the CSA Mine. This involved the development of ten raises using full-face raise boring from surface to a depth of 1450 m. The total length of the raises was approximately 2500 m. Geotechnical conditions were identified as a key project risk during the early planning stages of the project. Timely quantification of the geotechnical risks was required to minimise project delays and cost overruns. Geotechnical investigations were planned and conducted for each raise prior to pilot drilling and full-face back reaming.Nine of the ten raises had final wall camera and laser baseline surveys completed following full-face reaming. The surveys were conducted progressively, allowing ongoing back analysis and calibration of geotechnical evaluations as the project advanced.This paper presents the design and planning process of the raise bored excavations. It details the geotechnical investigation work undertaken to mitigate the geotechnical risks and the challenges and learnings from the project including the benefits of close collaboration between the parties involved.CITATION:Sidea, D and Brettell, T M, 2017. The CSA ventilation upgrade – geotechnical challenges and learnings, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 341–352 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By Smele J. S, Dawes W. D

In recent years there has been a trend among mining companies to diversify exploration and development away from the countries that have dominated mining activity for the latter half of this century. With some exceptions, this trend is accelerating and is a function of the recognition that many parts of the world, with no previous exposure to modern exploration, are endowed with considerable mineral potential. In addition coincident with changing political and economic circumstances, many countries have recognised the benefits of attracting international mining investment and have radically changed policies, fiscal and legal regimes so as to encourage exploration and mining. Some countries, however, have not readily accepted mining for cultural or social reasons and have yet to make effective changes to mining legislation. For historical reasons, other countries may have little or no direct experience of western economics, nor may they fully recognise the need for stability and competitive fiscal and legal systems to attract foreign investment. Not all ventures in new countries have been commercial successes and there have been some lamentable and recent lapses from grace. Company strategies, company standards and management objectives can also vary widely from company to company. What may be an acceptable risk or rate of return for one may be completely

Jan 1, 1997

By Bure R

Approximately 2.4 million ounces of gold and 11.3 million ounces of silver have been produced from the Umuna Lode by Misima Mines Pty Limited between June 1989 and the end of Decemeber 1996. Reserves remaining at the end of December were 32.1 million tonnes at 1.0 gram per tonne gold and 9.7 grams per tonne silver. To attain precious metal production of this volume, an estimated K60,000,000 (1996 Kina) was spent on exploration alone. from the 1940s to the present day. Exploration expenditure for the 1996 calendar year was approximately K4,400,000. With such a large investment in exploration, large quantities of data were generated and stored in various forms. To make best use of this data, it was necessary to organise and systematically store this data in a form compatible with a modern Geographical Information System (GIS). The Umuna Lode on Misima Island is a low sulphidation gold- silver deposit dated at 3.5 ¦ 0.2 Ma. The deposit is controlled by the 50 to 100 metre wide Umuna Fault- a moderate dipping, brecciated clay- chlorite- carbonate altered, normal fault zone. There is approximately 230 metres of mostly dip slip offset on this fault, which is measurable by the offset of the Cretaceous schist, marble and greenstone host sequence. Late Miocene microdiorite spatially related to the Umuna Lode does not appear to be genetically related to the gold- silver mineralisation. GIS was introduced to Misima at the end of 1995 and until recently has been mostly used for data storage and retrieval, the over- laying of various data sets to assist in targeting prospective areas, and as a drafting tool. The use of data-driven, predictive data analysis is the most recent effort in maximising the use of the extensive Misima database. By characterising the key controls and properties of the Umuna- type mineralisation, a Weights of Evidence, data-driven analysis produced a prospectivity map of Misima Island. The purpose of this map was to identify prospective areas yet to be explored and to assess the effectiveness of exploration to date.

Jan 1, 1997

By P Dunn

Following civil war in Sierra Leone, London Mining Plc obtained the mining license in 2006 and commenced activity to redevelop the Marampa mining and processing operations. The Sierra Leone Marampa mine is a brownfield development effort, having been operated by a few companies since the 1930s until low iron ore prices forced closure. Peak production of the preceding operations was approximately 2.5 Mt/a in the 1960s. There are two virgin ore deposits of interest for development as well as a resource comprised of tailings accumulated from previous operations. The Marampa tailings operation (Phase 1a) is being implemented first with a 1.8 Mt/a plant producing 66 per cent Fe sinter feed, expandable to 3.6 Mt/a in a Phase 1b. The first phase is currently under construction with start-up expected in the third quarter of 2011. Further expansion (Phase 2) that includes the development of the virgin deposits is currently under prefeasibility study and targets a final 16 Mt/a concentrate production. Outotec partnered with London Mining to develop the magnetic separation flow sheet using SLon VPHGMS machines to process the Marampa tailings (haematite) material. The flow sheet development process started with sample characterisation and detailed parametric investigations to evaluate SLon performance. The final flow sheet configuration, including expected circuit recoveries and concentrate quality, demonstrates the performance of the SLon VPHGMS circuit for iron ore tailings.

Jul 11, 2011

By M Dalm

More and more mining companies are becoming aware of the potential benefits of sensor-based ore sorting and process optimisation. This is reflected by a growing number of analysers that are available for drill hole logging, conveyor belt scanning, ore sorting, slurry analysis, etc. These tools all rely on a specific sensor technology that can be used to detect a material property such as colour, density, mineralogy, or chemical elements. However, all sensors have restrictions on the minerals and/or elements that can be detected or inferred. This is caused by the physical mechanisms behind the technology and depends on mineral concentration and compositional heterogeneity of the ore. Since nearly every ore deposit is unique in composition and characterised by different geological features that drive heterogeneity, no one-size-fits-all sensor solution is available. This makes it difficult for mining professionals to find suitable sensing technologies that can help them solve problems and improve processes for their specific ore types.

Sep 1, 2024

By G Zhao, S Hapugoda, E R. Ramanaidou, P Hapugoda, Y Jin, G O’Brien

In 2021 the ports of Port Hedland and Dampier in the Pilbara Region of Western Australia handled 900 Mt of iron ore. This ore was produced in the Hamersley’s mines and transported by trains to the ports for subsequent export. Dust, which is generally considered to be particles less than 100 μm in diameter, is generated at all steps in the supply chain. Whilst all dust may have potential impacts on human health and mangroves and buildings a proportion of the dust is classed as respirable (PM10) dust, which consists of particles <10 μm in diameter. In 2021, in response to the community concern with iron ore dust, CSIRO commissioned an internal study to characterise and benchmark the dustiness of the different ores and to develop targeted strategies to minimise dust impacts, without affecting other iron properties, such as stickiness during transportation. A specific concern is that that the dust in the PM10 fraction may contain significant amounts of particulates, such as free silicates which may have health implications for the workers and residents. This study provided detailed mineral and chemical characterisation of the dust generated from the railed fine ore products for five generic Australian ore types: Australian Channel iron Deposit (ACID), Australian Brockman (AB), Australian Marra Mamba (AMM), Australian Pilbara (AP) and Australian magnetite (AM). The dust from these fine ore products were compared to that generated from a sample of Brazilian Hematite (BH) type ore fines. The ores were evaluated for their physical, chemical and mineralogy properties, dust generating potential and understandings of the relationship between the dustiness of iron ores and their physiochemical properties. The size distributions of the railed fine ore products were determined and a suite of analyses were conducted on subsamples of total (-106 μm) and fine (-38 μm) dust. For all the ores, the total dust fraction contains less Fe and more contaminants (SiO2 and Al2O3) than did the bulk ore. The fine dust fraction contained even less Fe and more contaminants (SiO2 and Al2O3) than the total dust fraction. This suggests that the iron ore dust contains more clay and potentially free silica than does the bulk ore. These findings were supported by optical and Scanning electron microscopy analyses of the samples. Dustiness measurements were made for each of the different ores (-106 μm) to investigate the relationship of dustiness of various iron ores with their physiochemical properties and assess their responses to dust suppression by the application of water sprays.

Sep 18, 2023

By M I. Roberts

Corporate and workplace culture, as many owners, directors, executives and managers know, is by far the most powerful determinant of productivity. It’s much more significant than buildings and equipment. Yet although no one today would build a building or machine without a plan, few leaders have a plan for building and sustaining a safer and more productive culture.Using practical ways, culture can be planned and shaped as desired. Success requires implementing a project plan for changing the systems that drive behaviours that in turn shape attitudes. The combination of behaviour and attitude together with leadership largely shape culture.To improve performance, leaders need to:1. improve the organisational systems that drive behaviour2. action a project plan for improving specific performance metrics 3. demonstrate leadership that is conscious, disciplined, committed and passionate for purposeful use of human energy.This paper explains all three factors in practical ways with operational and corporate examples. It details understanding and applying the power of fundamental statistical analysis tools to recalibrate, focus and drive proactive leadership that takes responsibility for process improvement, supporting people and ensuring accountability.Experience and practical understanding of human and organisational behaviour confirm that the Measurement ? Analysis ? Reporting system combined with conscious leadership is by far the most powerful driver of behaviour. This wisdom produces profound changes in leadership style and behaviour. It develops outstanding leadership to create and sustain a safe and highly productive culture reliably producing consistently high quality products. It is the key to developing accountability, employee retention and a sustained competitive advantage.CITATION:Roberts, M I, 2016. Building safe, productive cultures and leadership, in Proceedings International Mine Management Conference, pp 163-178 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

The Black Star lead and zinc ore-bodies, situated in the western zone of mineralisation at Mount Isa occupy an area 2000 ft. long with varying widths from 100 ft. to 300 ft. The strike is N5&#176;W, and the average dip 60&#176; West.To test at depth the potentialities of this area, an extensive diamond drilling campaign was commenced on 16th October 1927. It was continued, with from one to six machines working, until the end of 1931. During this period, 26 inclined holes, with an average depth of 1224 ft, and a total footage of 31,828 ft. were completed. A vertical hole, 2452 ft. deep, for comparative purposes, has been omitted.These drilling operations came directly under the charge of G J Gray, General Superintendent of Mount Isa Mines, and, in the early stages were supervised by E. D. McDermott, of the Mining Trust, London. The foremen, who were in charge of various sections of the drilling operations, were: H Vale, F Bray, J Winston and A A Sanstedt.

Jan 1, 1932

By E N. Sparg, O D. A Deuchar, F Needham

Decline shafts are an attractive option to both new and existing mining operations where there is a need to access an inclined orebody deposit via on-reef development so as to generate a return in the shortest possible time. There are many different technologies that are available to transport men, material and rock in incline shafts. This paper focuses on the applicability of two hoisting technologies for decline shafts, namely endless and direct rope systems. The pros and cons of each system are reviewed. A common concern with direct rope haulage systems is the possibility of generating slack rope during deceleration. This paper illustrates the issues involved in designing a system so as to avoid the possibility of slack rope. In conclusion, the key factors relevant to the selection of endless or direct rope haulages for a particular decline application are reviewed. The paper is a joint submission by FFE Minerals-Vecor and Qualter Hall UK.

Jan 1, 2005

By R Wynn, T J. Akroyd, C Costa

In an environment of lower zinc prices, falling revenues and reducing zinc feed grades, Century mine implemented a fast-tracked capital upgrade program in less than 15 months. The program was designed to increase ore milling throughput capacity by 20 per cent and optimise the capacity of the flotation plant to increase zinc recovery by approximately 2.5 per cent whilst maintaining final zinc concentrate grade.A key aspect of this program was minimising capital expenditure by better utilising existing capacity and only adding capacity where absolutely required to address critical processing bottlenecks. By gaining an understanding of plant process bottlenecks and future ore blends, and by carefully selecting appropriate technologies for particular specific flotation applications, maximum return on minimal capital investment was achieved.The close collaborative work achieved between the metallurgy processing department and other operational departments on-site was also critical to the success of this project. This work increased the mining and processing capacity of the mine and port site respectively, such that the full value of the process plant modification could be achieved.Capital payback on this investment was achieved in approximately three and a half months.This case study demonstrates the extra value to a mining business that can be achieved through fully understanding the mining/processing value chain and by careful targeted action to address critical bottlenecks in the processing chain from the mine through to the port site.CITATION:Akroyd, T J, Wynn, R and Costa, C, 2014. MMG Century Mine, a case study – maximising project net present value through targeted capital expenditure and process optimisation against a backdrop of falling metal prices and feed grades, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 417–426 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By Sowerby BD

The CSIRU Division of Mineral Engineering is developing various techniques for the on-line determination of moisture in coal and coke, and some instruments are now commercially available. These techniques permit accurate and rapid determination of moisture in materials directly on conveyor belts or in bins. The most promising techniques for direct on-belt measurement of moisture in coal are capacitance and microwave transmission. A non-contacting under-belt capacitance and gamma-ray backscatter technique has determined moisture in coal to better than 0.5 wt&apos;/. in field tests at BHP Stockton Borehole Colliery, NSW. Mineral Control Instrumentation Pty Ltd have been licensed to manufacture the capacitance gauges and have installed five commercial units in the coal industry and other industries. Microwave transmission techniques have an advantage over the under-belt capacitance technique in that they are not sensitive to vertical segregation of moisture in coal on the conveyor belt. A laboratory prototype of a microwave transmission gauge has been constructed and tested. Microwave techniques, based on a measurement of attenuation and phase shift, are under development and are expected to be field tested in 1987. These new techniques will enable a wide range of thickness changes to be accommodated. Capacitance and microwave transmission methods are unsuitable for materials of high electrical conductivity, such as coke. CSIRO is therefore developing a fast neutron and gamma-ray transmission technique, which is proving very accurate in laboratory tests. This technique overcomes many of the limitations of thermal neutron moisture gauges and it is expected to be field tested in 1987.

Jan 1, 1987