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By D Cooke

In 2010, Kalgoorlie Consolidated Gold Mines (KCGM) was Australia’s largest gold producer, with total annual production of 788 000 ounces. Of the gold produced by KCGM in 2010, 95 per cent was extracted from the Fimiston open pit, also known as the Superpit. The Fimiston operation encompasses the historic Golden Mile, from which more than 55 million ounces of gold have been extracted from the world-class Fimiston lode style mineralisation.The operational performance of the KCGM Fimiston open pit was reviewed for the period between 2005 and 2010. Key performance metrics reviewed included mined tonnes and grade, cost per ounce of gold produced and the mine to mill reconciliation trends. The years 2007 and 2008 were characterised by a decline in performance against key performance metrics. The ore zones were diluted, with the excess tonnes mined resulting in lower grade and an increase in the cost per ounce. Poor reconciliation between ore mined, the ore reserve model and the grade control polygons was also observed.A series of improvement initiatives were implemented in late 2008. As a result of changes made to the grade control and mining practices, the site performance recovered. Unplanned dilution was reduced, which had a positive impact on mined grade. The lower tonnes combined with higher grade reduced the cost per ounce to below budgeted levels in 2009 and 2010, enhancing the profitability of the operation. The operational performance between 2005 and 2010 was compared to the turnover statistics for the KCGM geology department over the same period. Turnover accelerated between 2005 and 2007, peaking at an annualised rate of 43 per cent. With the onset of the Global Financial Crisis and the implementation of retention initiatives, turnover reduced significantly between 2008 and 2010. A strong consistent correlation was observed between the turnover trends in geology and the performance of the grade control function and resultant site metrics.The cost of turnover is known intuitively, however, rarely quantified. To evaluate the benefit of the improved performance, a detailed financial model was used to quantify the impact of the grade control function. In 2010, the headgrade exceeding budget by just four per cent contributed an additional A$24 M of value to KCGM. In contrast, if the 2008 performance had been replicated in 2010 (-9 per cent on headgrade), the result would have removed A$61 M in value from the business. The KCGM experience between 2005 and 2010 demonstrates the value of human capital in a mining operation and the importance of a high performing geology grade control team to the profitability of a mining operation.

Aug 22, 2011

The Louvicourt Mine is located 600 km north of Montreal in the province of Quebec, Canada. The owners are Aur Resources Inc (30 per cent), mine operator, Novicourt Inc (45 per cent) and Teck Corporation (25 per cent). It is an underground mechanised operation with a total work of 290 employees. Since 1994, the mine production is 11 120 456 tonnes at 3.60 per cent Cu, 1.51 per cent Zn, 26.07 g/mt Ag and 0.96 g/mt Au. At a rate of 4300 tonnes per day 365 days per year. Louvicourt Mine is a copper operation since 80 per cent of our revenue is from copper. The mining method is transverse blasthole stoping, mining primary and secondary stopes. The stope dimension is 15 m wide by 30 m high and 10 m to 80 m long for primary stopes. The secondary stopes are limited at 25 m long. Close to 100 000 metres of production drilling per year is required for 115 mm and 165 mm diameter holes. Backfilling is done with pastefill from the start of the operation in 1994. The binder ratio is 4.5 per cent in primary and two per cent in secondary stopes (80 per cent slag and 20 per cent cement). Development requirement to maintain production was 5000 m from 1996, 1997, 1998, 4200 in year 1999, 3200 m in year 2000 and an average of 2500 m in 2001 and 2002. Typical 6.0 m + 4.3 m, 4.9 m + 4.6 m and 4.5 m + 4.6 m headings. In addition more than 1500 metres of development will be excavated in/under paste backfill before 2004. A total of 60 mobile units are required among which for lateral development (three two boom electric hydraulic jumbos û AC Boomer 322, four electric hydraulic roofbolters û Maclean MEM-928 and AC Boltec PL350 and two anfo loader truck û Dux) and for production (four ITH drills û MTI, one electric hydraulic longhole drill û AC Simba H1357, eight LHD û AC-Wagner ST8-B, 1 LHD ST-1000 and two haulage 30 tons trucks û Dux. The 1 January 2002 reserves are 4.1 M tonnes grading 3.1 per cent Cu and 1.9 per cent Zn at an NSR (Net Smelter Revenue) of $US 53. The operating mining costs were at an average of $US 23 from 1996 to year 2000 and $US 25 in 2001. The operating costs ranged from a low of $US 0.41 per pound of copper in 1999 to a high of $US 0.49 per pound of copper in 1998.

Jan 1, 2002

By P Klaric, N Swart, S Barnes

The recent advances in digital imaging technology, specifically around photogrammetry, have facilitated precision measurement in the difficult conditions encountered in an underground development mining environment. With the recent downturn in the resources industry, many mining houses have begun to focus on cost reduction projects and driving efficiencies. The application of digital photogrammetry has allowed greater insight into the development mining cycle and supported a focus on areas where efficiencies and cost savings can be achieved. Data collation, via digital image capture, can be completed with minimal disruption to the development mining cycle with analyses taking a nominal time to process and interpret. The result can be a stark visual representation of the result of blasting and associated activities of the development mining cycle. Many millions of dollars of benefit can be derived from understanding the impact of each component of the development mining process, with some of the biggest savings associated with conformance to drill design and the minimisation of overbreak during blasting. This paper will explain the image capture process, analyses and instigated improvement opportunities that were undertaken at a number of mine sites to improve efficiencies and drive savings in their development mining processes.CITATION:Klaric, P, Swart, N and Barnes, S, 2017. Digital imaging provides valuable insights into underground development mining, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 129–134 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

This research is about human development and socio-economic progress of the main mining areas of Chile in the period 1990 - 2007, and especially about the positive effects that mining activity has on poverty reduction and indicators related to the Millennium Development Goals of the United Nations. The analysis is doubly interesting, if one considers that the economic and social developments in Chile, recognised and prominent among the Latin American economies and developing nations, are more evident in mining areas as Tarapacß and Antofagasta (northern Chile), which concentrated than more 70 per cent of investments and mining assets in the country. Additionally, the study concludes with methodological reflections for the evaluation of socio-economic impact in the mining industry in developing countries.

Jan 1, 2009

By Q Wang

Net present value (NPV) has been the main criterion in mining project evaluation and production plan optimisation. It is a common practice in NPV calculations to take into account only the tangible cost items in the corporate accounting system. The costs incurred due to damage to the local ecosystem and environment are left out and treated as externalities. Such practice on the one hand underestimates the total cost of a mining operation and, on the other hand, ignores the difference in ecological/environmental impacts between different mine plan alternatives. This paper attempts to measure the ecological costs of mining and to incorporate such costs into the evaluation scheme in mining project evaluation and mine planning. The ecological costs of mining are estimated based on the areas and types of land (eg forest land, grazing land, crop land) damaged by mining activities and the carbon emission from fossil fuel consumption. For the land areas (and their associated ecosystems) directly damaged by mining activities, the ecological costs are measured by the prevention and restoration costs, the lost values of eco-services of the damaged land, including bio-product production, soil erosion control, water run-off control, oxygen release, air pollutant absorption and formation of soil nutrients. The ecological cost of carbon emission from the energy consumption of a mining operation is measured by the cost of cultivating the equivalent forest land required to uptake the emitted carbon. A case study on a large-scale open pit mining project is presented to demonstrate the influence of ecological costs on the mine planning outcome.

Sep 26, 2011

By H-S Yang, H Park, S-J Kim, Y-H Ko, H-S Kim, S-H Cho, J-K Kim

An investigation was undertaken to devise a new method for reducing dust spread during blasting demolition utilising water tube and detonating cord. Modelling of smooth particle hydrodynamics (SPH) with AUTODYN software was initially completed to determine the expected diffusing behaviour of the water tube. The actual behaviour was then captured with high speed videos during each experiment, and each result analysed in detail. Water mist diffusion was generated and analysed by changing three key variables. In sequence, these included changing the location of detonating cord in the tube, the charge quantity and the tube diameter.As a result of experiments and simulation, optimum design for ideal diffusion behaviour was suggested and each behaviour of water mist was classified by diffusing shape of water tube as the design criteria.CITATION:Ko, Y-H, Kim, J-K, Kim, S-J, Park, H, Kim, H-S, Cho, S-H and Yang, H-S, 2015. Mist diffusion experiment and evaluation of water tube for blasting demolition dust control, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 809–814 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By R Baumgartner

The Canahuire deposit is a recently discovered Au-Cu-Ag epithermal deposit in Southern Peru. A geometallurgy program is a key study element of the project Feasibility study. Metallurgical, mineralogical, and comminution studies have been completed over a suite of samples, spatially distributed among the various geological/ore domains. The early stage of Canahuire presents challenges as there is a lack of metallurgical information to guide geometallurgical sampling, in contrast with an established deposit at a more advanced stage of development or mining. Nevertheless, the available information will assist in the development of geometallurgical domains for Canahuire in order to ensure that future metallurgical, mineralogical, and comminution test work is representative of the deposit variability. This supplementary knowledge will be able to predict important metallurgical parameters which will be incorporated into a geometallurgical model to spatial predict material types, metallurgical recovery and through put. The information obtained will be a valuable addition to the future mine plan, influencing process design, engineering design, plant operation, operating and capital costs, and ultimately will reduce project development risk.

Sep 5, 2011

By J L. Mauk

The Favona adularia-sericite epithermal Au-Ag deposit is located at the southern end of the Hauraki Goldfield, about one kilometre southeast of the world-class Martha deposit. The deposit occurs in Late Miocene andesitic lava flows and local dacitic tuffs of the Waipupu Formation. In some places, post-mineralisation ash fall and ignimbrite, up to 50 m thick, cover mineralised rocks and andesite. We collected soils samples from 110 sites along eight traverses over Favona, and from three regional lines: two south of Favona, and one north of Favona.   Analyses of soils identify prominent enhanced concentrations of Au, Ag, and Hg, and lower enrichments of Sb and As. At Favona, Au and Ag appear to be highly anomalous in areas over mineralisation with Au concentrations greater than 100 ppb and Ag concentrations greater than 1000 ppb, whereas background concentrations are approximately 5 ppb and 50 ppb respectively. The background concentrations of Hg in soils are approximately 100 - 200 ppb, but in mineralised areas, Hg generally exceeds 200 ppb, and some soils contain greater than 600 ppb. Antimony shows enrichments, although weak, above known veins and As locally shows some enrichment above areas of known mineralisation. Therefore, soil sampling at Favona defines geochemical anomalies that correlate with the position of known mineralisation at depth. Thus, there is strong empirical support for the use of Au, Ag and Hg, and possibly Sb and As geochemistry to identify mineralised trends associated with buried deposits at other epithermal prospects.

Jan 1, 2007

By Robertson AC

Studies by Tennent, Isokangas Pty Ltd (TIP) have indicated that underground quarrying of backfill may be a cost competitive option for providing backfill for specialised situations in underground mining. Situations where suitable bulk fill material may not be available on the surface, and where the total cost of setting up a fill distribution system are prohibitive, could favour the mining of fill material underground adjacent to the stopes being mined. Considerations include environmental impact, scheduling, surface constraints and total costs. The examples quoted in this paper, and the case studies are based on the authors' personal observations and experience.

Jan 1, 1998

The paper covers the history and develop- ment of electrical and diesel-powered hydrau- lic percussion rock drills. It examines main design aspects and problems encountered in pro- ducing an efficient and reliable machine to fully cover the nominal hole sizes required for underground development, production drill- ing and for general quarry work. The main design features and advantages of a hydraulic rock drill are relatively low input power requirement to energy per blow (this being achieved by the use of an electric or diesel- powered hydraulic system) and a specially con- structed piston using a powered damper cylinder to absorb the recoil forces from the drill steel and reduce stresses on the drill, feed and hydraulic boom. A further important design feature is the anti-jamming device which controls the drill both during manual and automatic operation. This anti-jam device works on feed and rotation press and prevents the drill bit becoming jammed in broken or soft ground. These features and many other mechanical and environmental benefits are highlighted when comparing hydraulic percussion rock drills with current pneumatic machines. The hydraulic rock drill gives an overall high penetration and production rate, with an added bonus for ergonomy and environmental conditions such as lower noise level, no fogging from air and oil exhaust (which naturally gives better air for breathing),plus improved vision when in under- ground situations. Hydraulic rock drills and systems have been fully tested in many mines, quarries and contract sites during the past years. They h6! been improved and modified and are now provi~ to be very reliable and economical piece drilling equipment whò in mines and quarries.

Jan 1, 1978

By M Binks

The Fosterville Gold mine is located approximately 20km to the East of Bendigo in central Victoria. The gold at Fosterville occurs as solid solution within disseminated arsenopyrite and pyrite. The Fosterville ore bodies contain various amounts of native carbon in the form of bituminous coal. This carbon (Non-Carbonate Carbon or NCC) has been the predominant mechanism for gold loss from the processing facility through”preg-robbing”.Processing of the Fosterville ore is achieved initially through crushing, grinding and flotation to extract the sulphides. The sulphide concentrate is oxidized using Bacterial Oxidation, before being leached in a conventional CIL circuit. A high portion of the native carbon (NCC) in the mine ore is naturally hydrophobic in nature, and subsequently reports to the flotation concentrate stream, and ultimately onto the CIL circuit. This NCC has a notable preg-robbing ability. Treatment of Black Shale ores, which have elevated NCC levels, has historically resulted in CIL recoveries as low as 35%, with around 60-80% of the gold loss from the leach circuit attributed to preg-robbing.Standard technologies for dealing with a carbonaceous leach feed have been trialed with limited success. The discovery of the significance of heat on leach recoveries, triggered extensive testwork on a range of leach feed and tails samples. Pilot plant testing demonstrated that “Heated Leaching” of the CIL tails was the best process with an average recovery increase of 7.5% being achieved. Following a successful pilot study, an engineering feasibility study was completed by Minerva Engineering, and the project economics determined. With strong recovery gains evident and a predicted project payback of 1-1.5 years, approval for the installation of the full scale plant was granted. Detailed design commenced in September 2008 with installation commencing in January 2009. The circuit was successfully commissioned in April 2009.Following commissioning, the Heated Leach circuit has achieved recovery gains of 4-14%, and has proven itself to be a significant contributor to the overall plant performance.

Aug 8, 2011

By J Pan, C M. Tang, D Q. Zhu, C C. Yang, S W. Li, Z Q. Guo

The short process of electric furnace steelmaking with direct reduction iron (DRI) as raw material is an important process for smelting high-quality and special steels. In order to prepare high-quality DRI, the pellets with basicity of natural basicity and 0.4 were prepared from magnetite concentrate (MR=0.09, MR=0.4) and hematite concentrate (HR=0.02, HR=0.4). Based on the HYL method, the gas-based direct reduction experiments were conducted under the condition of rich hydrogen (H2/CO = 2.6). The reduction index (RI), reduction swelling (RSI), cold compressive strength (CCS), and phase changes of the pellets were systematically studied. The results show that the RI of four kinds of pellets is greater than four in the temperature range of 800~950°C. For the magnetite pellets, at a fixed reduction temperature, the RSI increases and then gradually decreases, reaching a peak between 50 per cent and 80 per cent. Moreover, the RSI enhances with the increase of the reduction temperature. In general, the RI, RSI, and reduced CCS of the MR=0.09 pellets are better than those of the MR=0.4 pellets. For the hematite pellets, the maximum RSI decreases from 23 per cent to 17 per cent during hydrogen-rich reduction, while the compressive strength increases from 500 to 1070 Nꞏpellet-1. The main reason is that the glass phase generated by the increase of basicity adheres to the surface of hematite grains, hindering the contact between reducing gas and particles. As a result, the apparent activation energy is reduced, which is not conducive to the reduction process. In addition, the glassy phase attached to the hematite reduces the migration rate of Fe2+/Fe3+, resulting in a difference in the reduction expansion rate of hematite in the inner and outer layers of the pellet. Thus, concentric cracks are formed inside the pellets, the RSI increases and reduced CCS decreases.

Sep 18, 2023

By P Holtham, K Duffy, B, W Valery, E Tabosa, rade

Pre-concentration has potential to significantly improve Mineral Resource efficiency by removing gangue early in the process, before energy intensive and expensive comminution and fine processing. However, there are numerous options for pre-concentration and the performance and benefits of these are very case specific. To determine the best option for a particular deposit and to successfully integrate it into the overall mining and processing operations requires comprehensive evaluation. This needs to consider orebody suitability, technology capability and economic viability. The in-situ variability of a deposit and how it is influenced by mining methods and the liberation size of gangue are key factors which are generally not well understood. Geostatistical methods provide an insight into orebody variability, and the overall selection of any pre-concentration solution must be an integrated approach between geology, mining and processing. Many pre-concentration evaluations investigate the potential of just one option. Technology selection should start wide and may include: selective mining, pre-screening (with or without selective blasting), sorting (bulk and or particle), coarse gravity separation (e.g. jigging, DMS), coarse particle flotation, magnetic separation, etc. The upgrade performance of these processes is very ore specific and should be determined from testing, with detailed multi-component modelling used to determine the overall process performance. Many of these pre-concentration processes require significant ancillary equipment, feed preparation and materials handling. It is important to realistically estimate all costs to understand overall economics and select the best option. Some examples showing evaluation and comparison of pre-concentration options are presented in this paper. These include assessments of in-situ variability using geostatistical tools, process modelling of pre-concentration options and overall performance, preliminary layouts and cost estimates, and economic evaluations.

Nov 10, 2020

In order to understand the technique, basic theoretical principles of radiation emission and in- strumentation theory are reviewed. Methods of surveying, reduction of data and interpretation are outlined. Other applications of the technique (e.g. in airborne geological mapping), as well as its specific use in uranium exploration, are discussed. By means of case history-type examples the successful applicant of gamma-ray spectrometry, as a tool in Australian mineral search, is demonstrated.

Jan 1, 1969

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

After some 50 years of worldwide research in relation to coal pillar mechanics and design as well as numerous workshops and technical papers related to these issues there is still some significant disagreement as to the approach one should adopt in the assessment and design of a coal pillar. Of course there are many different types of coal pillars that fulfil a wide range of roles at any particular mine and in this instance it is appropriate to have a 'tailored' approach for each pillar type in relation to the role it fulfils. However where it can become very difficult for the mine operators is when various researchers or consultants use or recommend significantly different approaches for the same type of pillar fulfilling the same role. By 1999 two pillar design techniques had been developed specifically for the Australian underground coal mining industry (ie The University of New South Wales Pillar Design Procedure, UNSW PDP and Analysis of Longwall Tailgate Serviceability, ALTS) and several other pillar design techniques were being practiced by individual consultants. The Australian industry hoped to resolve the issue of what technique to use for each pillar type and role, when it funded UNSW in 2000 to develop a 'Systems Approach to Pillar Design'. The findings of the abovementioned project were published in 2005 and while every attempt was made by UNSW to include the views of various local and overseas researchers and consultants it would be fair to say that a unified approach to pillar design in Australia was not adopted as a result of that project. This is the experience of one country where there has never been one central group solely undertaking such research in relation to pillar design (such as the Chamber of Mines in South Africa). This paper explores the Australian experience in terms of pillar research and what that experience may offer to researchers in Australia and other countries. At the First Australasian Ground Control in Mining Conference (2003) the first 'update' of the ALTS Design Methodology (ie ALTS II) was presented. In subsequent years the ALTS database was continually updated and significantly expanded such that it now includes detailed information in relation to both the tailgate (148 cases) and maingate belt road (58 cases). In addition to tailgate roof support and chain pillar design, the current version of ALTS (referred to as ALTS 2009) includes a maingate belt road roof support design module. This paper is also intended to update and summarise the development and application of the ALTS Design Methodology for longwall gateroad design over the last decade both directly and in the context of coal pillar research conducted in Australia over the last 15 years.

Nov 25, 2010

By S M. Jowitt, G M. Mudd

"The mining industry is the source for the vast majority of the metal, mineral and energy resources we use on a daily basis. New deposits are discovered over time and are developed into mines before being rehabilitated – a sequence that when repeated can help contribute to the noble notion of ‘sustainable development’, despite the generic concept of mining being the unsustainable consumption of non-renewable resources. The scale of the modern mining industry is immense – from iron ore and coal to base and precious metals, modern mines are sometimes hundreds or thousands of times bigger than their long lost historic ancestors. We also live in a world with emerging and increasing demands for so-called technology metals (aka ‘critical’, ‘e-tech’ or ‘specialty’ metals) that are needed to feed the rapid growth in renewable energy (especially solar photovoltaic panels and wind turbines), consumer electronics, sophisticated military technologies and super alloys, amongst other uses. These elements include the rare earth elements, indium, germanium, tellurium, rhenium, selenium, gallium and many others, most of which had few or no known uses in the recent past. Although the mining industry has been successful in developing ever larger mines and increasing the scale of production, the key issues underlying the future of the industry are declining ore grades, increased tailings and waste rock generation, the presence of toxic or other impurities, balancing the economics of primary and secondary products, stricter environmental conditions, more difficult exploration, increasing community expectations, as well as the processing of more complex or refractory ores, let alone the recent volatility in world commodity markets. Here, we synthesise our recent research on many of these various issues, focusing on the need to link all areas within the mining chain from mineral resources through mining to environmental performance in order to ensure we obtain the most out of our modern mining effort. The paper presents a unique and detailed assessment of the sustainability challenges and opportunities facing modern mining – and geometallurgical thinking is at the heart of this conundrum.CITATION:Mudd, G M, Jowitt, S M, 2016. From Mineral Resources to Sustainable Mining – the Key Trends to Unlock the Holy Grail?, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 37–54 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By L Köresaar, J Moilanen

With lower and increasingly variable Fe grades in iron ore resources, the monitoring of Si, Al, Mg and other light elements to meet quality requirements is gaining importance in the iron ore beneficiation industry. The high cost per manual assay and associated manpower requirements often limit the frequency of shift composite samples and laboratory assays. Furthermore, the shift composite assays represent past performance of a plant but are not useful for immediate reactions to feed variations, detection of equipment malfunctions or process control. Automated online analysis of light elements radically reduces the cost per assay and provides repeatable, timely data for process analysis, control and optimisation.A light element online slurry analyser, based on laser-induced breakdown spectroscopy (LIBS) optical emission technique, will be presented. This paper discusses the analyser design for the iron ore industry and also reviews the performance of the analyser against the manual laboratory. Additionally operator safety, user friendliness and maintenance requirements are discussed.A case study will also be discussed in this paper. The sophisticated measurement technique has been implemented in an industrial automated analyser and sampling system to allow for slurry measurement for up to 12 sampling points. However, careful selection of the sampling points and implementation of the sampling system is required for smooth operation.CITATION:Köresaar, L, Timperi, J and Moilanen, J, 2015. Optimised process control in iron ore via online analysis of light elements, in Proceedings Iron Ore 2015, pp 511–518 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By M Rafty, A Markham, S Atkinson

Australia contains some of the most productive mining areas and is characterised by ancient landscapes and highly variable hydrology. Historical mining of iron ore, coal and other minerals has targeted ore deposits located above water tables, and elevated above creek lines where possible to reduce cost. The downturn in mining caused by falling ore prices over recent years has triggered a drive to reduce cost, maximise yield and delay capital expenditure associated with opening new mines. So as the ore deposits with more favorable mining conditions become depleted there is an increased focus on mining ore associated with valley floors and creek lines. This is demonstrated by a regional assessment of the extent of Channel Iron Deposits (CID) and Iron Ore (Fe) Mines and Deposits in the Pilbara Region of Western Australia (Figure 1). A large proportion of these mines are, or plan to, target high grade CID ore associated with existing creek systems. Figure 2 shows outcropping and inferred sub-cropping CID extents, which suggests there are vast quantities of CID ore deposits throughout the Pilbara Region, intersected by major creeks which could be mined at some point in the future using creek diversions (Atkinson et al., 2017). A similar picture could also be produced for coal mining in Queensland, particularly in areas such as the Bowen Basin.While creek diversions provide an opportunity to maximise the utilisation of these orebodies and extend the life of mine, creek diversions can involve substantial financial, social, environmental and regulatory risks that need to be carefully managed (Markham et al., 2017, Atkinson et al., 2017). This paper discusses the key issues and opportunities associated with diversion decision making. It highlights the importance of using a well-structured assessment methodology that allows key stakeholders to be part of the assessment process and is complementary to material presented in Atkinson et al., (2017). Design considerations for operational and closure designs are presented, as well as mine planning considerations, risks, cost saving opportunities and the benefits of an integrated approach to design. The role technology plays in diversion design and performance monitoring is discussed as are the potential opportunities for the future.CITATION:Atkinson, S, Markham, A and Rafty, M, 2018. Diversion decision making with an integrated approach to design for operations and mine closure, in Proceedings Life-of-Mine 2018, pp 74–79 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

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