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By J Coombes

Within the mining industry there is a growing trend of placing inexperienced technical people into positions of responsibility beyond their readiness. Their responsibilities often include providing the fundamental basis for decision-making: the resource model or even the daily grade control estimates. Whilst software continues to make the processes more accessible, the thinking and rationale for selecting parameters still requires control rather than auto-piloting. Operators run these systems in virtual isolation, and have limited immediate access to experts. Beyond the stress of the professional burden are the increased risks to the mining operations and overall project success.While many experienced experts recall being thrown in the deep end, the relative isolation from experts coupled with the gravity of professional burden before readiness, is less familiar. Many recall in intimate detail the experts who gave them direction, assisted them along the way and even helped them claw out of inadvertent mistakes. Experienced professionals all have a responsibility to enable capability across the generations, to ease the burden and to mitigate the risks.This paper provides an outline of how mentoring as an on-the-job professional development process can be structured to more fully enable success of a mentoring program. Three examples complement the principles presented.CITATION:Coombes, J, 2012. Structuring meaningful mentoring, in Proceedings International Mine Management 2012, pp 15-22 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By Holmes R. J, Miles J. G

An on-stream shale detector has been developed that is suitable for use on conveyor belts carrying iron ore of up to 200 mm particle size. The shale is distinguished from high-grade iron ore by means of the substantially greater total natural gamma-ray activity (400-3000 keV) of the shale, which is due to the presence of uranium (214Bi), thorium (208TI) and potassium (40K). Other gangue materials, sueh as highly siliceous cherts and jaspilites, escape detection because of their low activity. A dynamic trial of the shale detector at Mt Whaleback, using a large-volume (100 × 100 400 mm long) "Polyscin" Nal(TI) gamma-ray detector, demonstrated that as little as 20 tonne of ore on a conveyor belt (equivalent to partial truckloads of ore) can readily be monitored for shale content.

Jan 1, 1981

By R Stimpson, B Johnson, B Hesse

During a period of twelve months between FY18-19, a series of trials were conducted to compare production drilling accuracy using two different methodologies, and the subsequent impact this had on stope performance (dilution and recovery). Testing was conducted at a series of underground mines in Australia. The drill rig’s existing alignment processes were compared to a new technology system, with the following observations: • The new technology was proven to limit rig alignment error, thereby reducing average blasthole deviation, resulting in an increase in the number of holes drilled within tolerance by up to 160%. • The increased accuracy reduced stope dilution significantly by reducing over-break of subgrade ore, whilst also increasing drilled meters (faster stope-cycle time), reducing the bridged tonnes ratio, and facilitating the capture of previously uneconomical stopes. A cost-benefit analysis extrapolated from each of the trials showed the extent to which the new technology, when applied to production data, reduced average dilution, increased ore recovery as well as general drill and blast productivity. In one such trial, the new technology was proven to have reduced average dilution by net 45.4%, which if applied to a full year’s production data, would result in AUD8.2M additional ore recovered, with AUD4.5M less spent on wasted cost of haulage and processing of diluted ore. As a result, return per tonne would increase 22%, from AUD87 to AUD106. This improvement was maintained over the following 12 months – reducing average dilution from 22% in FY17 to 12.1% in FY19.

Mar 15, 2021

The difficulty of accurately sampling cyanide gold bullion for valuation is well known, and nothing new or original is claimed in presenting this paper, but it was thought that a record of differences in the composition of bullion bars found here may be of interest to others, and perhaps helpful to those who have to do with theevaluation of cyanide bullion. This investigation was made after reading Mr. Sydney W. Smith's interesting paper on the Liquidation in Molten Alloys.*A method was in use of boring each ingot in two places and mixing the two borings for the sample. More accurate values were obtained, however, when the bullion was sampled in a molten condition immediately before casting into the ingot; the sample being so taken as to preclude oxidation of base metals before solidification of the sample.In all, samples from 32 ingots were assayed, and comparisons made between the existing boring sample and the proposed dip sample. Assays were also made of two other portions of the borings from each ingot, and the results show that in the majority of cases the borings sample assays higher in gold than the dip sample of the same ingot.The largest ingot cast weighs approximately 920 troy ounces, and has the dimensions shown in the attached sketch (Fig. 1). Ingots are cast in 0.1. moulds i in. thick, smoked and heated.METHOD OF TAKING BORING SAMPLES OF BULLION BARSThe bar is cleaned from adhering slag and drilled in two places only, to a depth of i-in., one hole on the top near one end and the other in the bottom at the opposite end of the bar.

Jan 1, 1931

By Y Li, Z Fu, D J. Williams, E Topal

Mine waste rock is unavoidable in the recovery of ore by open pit mining methods. Effective management of waste rock movement covers the removal and placement of the waste rock, generally in a surface dump in the most cost-effective way while satisfying the long-term environmental expectations. Since the 1960s, there has been significant research carried out into planning of ore movement from open pit mines such that the overall net present value (NPV) of the project can be maximised. Currently, several software packages are available to achieve this task as a common practice within the mining industry. However, planning of mine waste rock movement is still achieved manually, as the available software does not consider optimal waste rock movement and dump design. This paper describes a tool to optimise waste rock placement, which minimises the haulage cost while creating environmentally friendly waste rock dumps through selective placement and encapsulation of the reactive waste rock in the dump. The embedded methodology in this tool has been developed based on the mixed integer programming (MIP) modelling technique to optimise the waste rock movement. The methodology provides an easily-manipulated and fully-automatic tool for professionals to complete waste rock dump scheduling in four main steps: data input, model construction, model computation and solution retrieval. The application of the new tool into a real case project in this paper shows that it can determine economically and environmentally optimised waste rock dump schedules in an acceptable time frame.CITATION:Fu, Z, Li, Y, Topal, E and Williams, D J, 2015. A new tool for optimisation of mine waste management in potential acid forming conditions, in Proceedings Tailings and Mine Waste Management for the 21st Century, pp 333–342 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By R Redden

"The Didipio Gold-Copper project in the Philippines has been a well-defined reasonably high gold grade porphyry for almost two decades. OceanaGold are now bringing the project into production in late 2012 and have recently reoptimised the project with the goal of combining the inherent high grades with higher through-put than previously proposed that will see strong initial metal production. The project was discovered and well defined by 1995, but has seen some obstacles to development, namely sovereign risk, capital cost and project funding. The project strengths over this time that have kept the flames alive are: strong grades large orebody with low stripping ratios a simple beneficiation process and a clean high-grade concentrate strong support from the Philippines government.The initial study in 1998 used Gold and Copper price assumptions of $325/oz and $0.95 lb respectively. Today reserves are based on $950 and $2.85. So, being a porphyry with a large reducing grade halo, the deposit now lends itself to extraction on a much larger scale than before, without any significant capital expenditure as a larger open pit now dominates the project.Didipio is a game changer for OceanaGold, so it has been important to learn from history and to capitalise on a strong initial metal production profile. The project sits in a reasonably remote mountainous area of Luzon which sees annual typhoons and numerous short duration high intensity rainfall events and two rivers flowing through the project area, so it has not been without some innovative technical solutions.CITATION:Redden, R, 2012. Didipio - Learning the lessons, adapting and getting ready for production, in Proceedings Project Evaluation 2012, pp 67-76 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

May 24, 2012

The district specially referred to in this paper comprises the very gently sloping country extending from the western shores of Port Phillip from the mouth of the Yarra to Footscray along the Bacchus Marsh railway to near that town thence in a southerly direction to the Little River, and along that river to the coast, 1 as may be seen on the accompanying map. Almost the whole of this area is covered by volcanic rocks, consisting of pumerous sheets of basalt, which have been poured out of various volcanic hills in the districts, such as Mts. Atkinson and Cotteril, near Melton; Mt. Maryand Bald Hill, 12 and 16 miles respectively N.W. of Werribee; and vents in different parts of the parishes of Tarneit, Mouyong, Mooradoranook, Pyweitjorrk, and Derrimut. These volcanoes were in an active state of eruption during a late period of the earth's historyprobably the late Pliocenll, or still younger Pleistocene.Occupying a narrow strip of country, for most of the distance along the coast from Williamstown to past the mouth of the Little River, there occur deposits of still younger age, belonging to the Recent period. These lie on the basalt, and extend for distances varying from a few chains to more than a mile back from the beach. They comprise superficial deposits of blown sand, and raised beaches, composed of marine sands...

Jan 1, 1902

By D A. Bowman, S Schafrik

With the goal of reducing injuries and fatalities related to haul truck accidents, this research investigates technologies and intervention strategies for improving worker training using a virtual environment (VE). Funded by the National Institute for Occupational Safety and Health (NIOSH), this research specifically focuses on training workers in preshift inspections of haul trucks to avoid preventable defects from causing worker injuries and expensive equipment damage. Improved training in these inspections is expected to increase uptime. The VE developed to train workers for preshift inspections consists of three phases: the virtual tour, the virtual inspection and the shift simulation. The virtual tour introduces information necessary to conduct a preshift inspection by guiding the worker around a haul truck, identifying parts to be inspected and explaining defects to look for. The virtual inspection assesses retention as the worker navigates around a haul truck and identifies defects. During the shift simulation, the worker is shown a simulation of the work shift, which animates severe consequences of any overlooked defects to emphasise the importance of preshift inspections. To provide multiple training platforms, desktop and CAVEÖ versions of the training VE were created. Flux Studio was used to model the environment and to produce Virtual Reality Modelling Language (VRML) files for the desktop version. DIVERSE, an application programming interface, was then used to implement a more realistic version of the VE in a CAVEÖ, a room-sized visualisation system. Initial feedback from mining colleagues indicates that the training VE may replace normal classroom training for preshift inspections in the future. As opposed to PowerPoint presentations and instructional videos, the training VE provides better spatial understanding of the location of parts and incorporates interactive features to actively engage drivers in the learning process, which may result in better retention. Initial feedback also indicates that minor improvements can be made to the virtual tour and virtual inspection phases.

Jan 1, 2008

Treatment of Gold-Bearing Oxide High-Clayish Ores The analysis of modern state of treatment technologies of gold-bearing oxide high-clayish ores showed that the main method applied both in Russia and abroad is sorption leaching and heap leaching with preliminary granulating. The use of any of these processes depends on many factors including average gold grade, site and area of a deposit, clay content and etc. The two processes are often used at the same deposit. In this case, rich ores are treated according to a plant technology, poor ores and ores with cut-off grade are treated with heap leaching. Both technologies possess their own advantages and disadvantages. A plant technology is characterised by high recovery with higher capital and operating costs at the same time. Lower recovery during heap leaching can be attributed to an unstable quality of ore granulating due to both technological and weather conditions. In case of poor high-clayish ores, the use of a combined ore treatment is possible and profitable. It includes the ore disintegration and a clayish fraction treatment by using a heap leaching. In this case, capital and operating costs reduce in comparison with a plant technology and the recovery increases in comparison with heap leaching. Sometimes it reaches a plant recovery. These ores possess special features. As a rule, gold is associated with ore fraction, so it liberates readily from the association with ore ore-forming minerals even with relatively coarse grinding explain their high solution velocity in a hydrometallurgical cycle. Clayish ores are characterised by high sorption activity to gold cyanide complexes as well as extremely low velocity of filtration and thickening of slimic pulps at the same time. The paper describes the options of oxidised high-clayish ores treatment, such as, a plant technology (PIP and CIP process), heap leaching and a combined technology (disintegration, heap leaching of a crystalline fraction and sorption cyanidation). The obtained results were used when selecting a treatment technology and during construction of a plant for oxidised high-clayish ores treatment.

Sep 13, 2010

By P Wood, S Leveritt

This paper will introduce some innovative strategies for simulator training that are intended to improve the level of safety and operational performance of heavy equipment operators. The key strategy is to design simulator training to deliver improved work performance outcomes. This strategy is underpinned by a process for engaging workers in knowledge discovery and transfer that has been developed as an outcome of an Australian Coal Association Research Program (ACARP) funded project conducted at open cut coal mines in Australia. The process is expected to deliver improvements in the safety and operational performance of heavy equipment operators by informing training content about how experienced operators manage unexpected situations around the site. Tapping into the tacit knowledge that experienced operators gather over time can provide site specific and timely information about situational cues used to manage the unexpected. This type of information complements basic skills training by helping the trainee understand the operational context in which the acquired skills will be applied. Inexperienced operators have traditionally gained experience through their own actions, observing the actions of others and by taking the advice of mentors who have æbeen there, done thatÆ and developed operational decision making skills for safe and productive work performance. Leadership and mentoring techniques that contribute to effective knowledge delivery will also be discussed.Other simulator training strategies include refresher training, change management, emergency response training and testing the usability of new equipment and technologies prior to their introduction on-site. A key challenge ahead for the resources sector is the development of knowledge elicitation techniques that suit the operational workforce. A challenge for simulation and modelling professionals is to develop and refine techniques that support cost-effective customisation and regular updates of simulator scenarios.CITATION:Leveritt, S and Wood, P, 2012. Raising the simulator training bar - Strategies for improved work performance and effective utilisation of site-based simulators, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 65-70 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

By Z Gao, D Liao, W Sun, S G. Pooley, J Wang, Z Shi, G Jing, S Ren, Q Chen

Yuanjing processing plant is a scheelite and wolframite plant in southern China. Water shortages and recent environmental regulations mean that the plant must reuse the wastewater that comes from the mining operation. This paper describes the efforts to reuse the mining and ore washing wastewater (MOW) in the processing plant. Initial attempts to reuse the MOW in the strong magnetic separation were unsuccessful because the magnetic media pack was seriously fouled by the micro-fine precipitate generated. The focus changed to reuse the MOW in the scheelite flotation circuit, which includes one roughing, one cleaning and three scavenging steps. Laboratory batch tests showed this would likely be successful because using MOW reliably improved the flotation performance in the laboratory tests. Then a 20 day industrial trial was run in the plant. The trial was very successful with the enrichment ratio of WO3 increasing from 17.4 to 23.6, while the recovery remained around 79.2 per cent. The industrial trial was so successful the company immediately adopted the new scheme, which has remained in use ever since. This technical solution not only alleviated serious water shortages, and satisfied environmental regulations but also improved the plant performance.

Aug 24, 2022

By M Graham, R Brunning, C Andringa-Bate, S Westergren

In 2010, Rio Tinto Iron Ore’s operations commenced the planning and design of a sampling and analysis system for the new 50 Mt/a Cape Lambert Port B (CLB) facility. Current sampling systems at the ports consist of automated robotic, mass-based sampling protocols employed at Dampier, and semi-automated, time-based sampling systems operating at Cape Lambert Port A.The new sampling system at CLB has brought together a fully automated sampling and analysis system utilising time-based sampling, with the capacity to sample ore products of medium quality variation as defined in ISO 3082 (ISO, 2009). The CLB system is required to sample at shiploading rates from 6000 t/h to 13 440 t/h and provide full load-port analysis. The sampling approach is to proportionally extend primary increments (of varying mass relative to shiploading rate) to a standard length using variable speed aero-belt conveyor systems. This enables a fixed number of secondary cuts to be achieved for all primary increment masses and to be delivered to the automated cell. The cell is required to be capable of concurrently processing four individual shipments, each containing multiple cargoes.Achieving the target sampling precision for all export cargo sizes has culminated in the planning, design and construction of the largest automated iron ore port laboratory in the world. The CLB sampling and analysis cell was commissioned in Q3 and Q4 2013. This paper discusses the sampling philosophy and commissioning outcomes.CITATION:Brunning, R, Andringa-Bate, C, Graham, M and Westergren, S, 2014. Cape Lambert Port B shiploading, sampling and analysis, in Proceedings Sampling 2014 , pp 79–90 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

Large GDP increases in the Pacific Rim countries have been accompanied by similarly large increases in demand for oil products. In the case of residual fuels, this demand has been tempered by the substitution of other energy products such as coal or gas. In the region's developing and newly industrialised nations, it has not been possible to make the very large investments in infrastructure which allow other energy sources to be used for transportation. As a result, GDP growth has been mirrored in the demand growth for automotive fuels. Other non-substitutable products such as lubricants have also benefitted by the region's GDP growth.   The combination of a number of years of sustained growth, coupled with increasing quality requirements is now stretching the upgrading capacity of the region's refineries. IT, as seems likely, the region continues to enjoy a high GDP growth rate, then this will be accompanied by increasing reliance on finished products coming out of the Middle East.   The owners of the most simple form of refinery in which crude is simply distilled and the naphtha reformed into petrol will face major capital investments. If they decide not to bear this cost, they will face increasing problems in selling their surplus residual fuel oil at an economic price. Quality will become an increasingly important issue. Not only in the well publicised areas such as unleaded petrol, but also for products such as lubricants which play a major role in the efficiency of modem equipment. Quality of service such as hours of opening, ease of access, and service station facilities will also become increasingly important as the oil companies use these to attract customers and gain brand differentiation.

Jan 1, 1990

By McLennan R. G

The principle of personal safety is as old as the human race. The application of this principle to industry is of much more recent origin, and may be said to be almost exclusively the product of the twentieth century. The enormous strides in technique and production mode prior to the turn of the century had been achieved without any real regard for the crippled human by-products of that expansive era. It was accepted that. accidents were inevitable and formed part of the price that must be paid for production. It was not until 1885 that the first Workmen's Compensation Act was passed in Germany making the employer financially liable for injuries suffered on his plant.With awakening social conscience came the first organised efforts to reduce accidents in industry. Early 19th century literature dealing with the development of powerdriven machinery and the growth of industry in Europe contains many references to the unsafe and unhealthy working conditions that accompanied the change-over from the home workshop to the industrial plant. By the year 1900, there were in Germany - and a little later in England governmental regulations dealing with the guarding of hazardous machinery. American industry, now the acknowledged leader in industrial safety, admits freely that when an organised safety movement commenced in that country, there was already a considerable amount of information available to them from European experience. The steel industry was well to the fore in this work, and in...

Jan 1, 1957

The construction of mine headframes of reinforced concrete is not a new departure as many structures have been built of this, material particularly in Canada and South Africa. This type of construction has been satisfactorily tested in service and is now accepted by the mining fraternity.The two headframes at New Broken Hill Consolidated Limited are the first structures of this type to be built in Australia, and provide an interesting application of reinforced concrete design and construction.Reasons for Adoption of ConcreteDuring 1947 the writer visited D.S.A. and Canada and inspected three headframes, of reinforced concrete construction.Leading details are as follows:(i) Hollinger Gold Mines. (Timmins, Ontario) : Height of sheaves 110 ft. Shaft has provision for 4 skips each of 12,000 lb. capacity. Structure incorporates surface crushing plant.(ii) International Nickel Corporation-Murray Shaft (Sudbury): Height to sheaves 153 ft. 6 in. Shaft provides for 2-12 ton skips and 2 cages. Surface crushing plant built integrally with frame.(iii) Asbestos-Johns Manviae (Quebec): Height of sheaves 116 ft. Shaft provides for 2 skips 200 cu. ft.

Jan 1, 1956

By J Seccatore, G Sadao, M Cardu, G De Tomi, L Finoti, F Galvão, J Romero Huerta, A Rezende, J Bettencourt

In the mining industry, rock blasting can be considered as the first phase of comminution. The downstream phases of comminution are mechanical, and consist in consecutive stages of crushing and milling for grain size reduction. The total energy of mechanical comminution depends on grain size and on the resistance of the material to grindability. Usually, the first is quantified by the grain size distribution or one of its KPIs (such as the diameters X50 or X80), while the latter by the working index (WI), representing the amount of energy necessary to reduce the size of grains of a determined amount of material to the desired equivalent diameter (usually expressed in kilowatt hours per tonne – kWh/t). It is widely recognised that it is possible to manage the output of a blast in terms of grain size distribution varying specific charge (powder factor – PF) and charge distribution; specific algorithms such as the KUZ-RAM or the SWEBREC have been created to predict such output. It has also been demonstrated how higher PFs weaken the blasted material by creating micro-fractures that reduce its WI. This paper focuses on a related aspect: the influence of charge distribution on the specific comminution energy in crushing and milling. Small-scale blasts have been performed on 14 marble blocks with different PFs and charge distribution. For every PF, charges have been designed to simulate concentrated and distributed geometries. Concentrated charges simulate opencast blasts with large-diameter holes, with large burdens and spacings. Distributed charges simulate bench blasts with small-diameter holes and reduced burden and spacing. Three control blocks have been fragmented by mechanical means for comparison. For every sample the grain size distribution and the WI in ball mill has been determined. Results show the correlations between charge distributions and the specific energy of mechanical comminution in milling. Finally, the opportunity of adjusting charge diameters and distributions in opencast blasts to improve the output of the comminution circuits is discussed.CITATION:Seccatore, J, Romero Huerta, J, Sadao, G, Cardu, M, Galvão, F, Finoti, L, Rezende, A, Bettencourt, J and De Tomi, G, 2015. The influence of charge distribution on the grindability of the blasted material, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 749–754 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

The El Pe±on gold-silver deposit comprises four epithermal, low-sulfidation veins, which contain 2.9 million oz Au and 48 million oz Ag. Provisional data on alteration mineralogy, fluid inclusions, and vein textures constrain the chemistry and hydrology of the hydrothermal system responsible for ore mineralisation at El Pe±on. Alteration minerals include quartz, adularia, albite, illite, smectite, calcite, chlorite, and pyrite. Alteration minerals suggest the existence of near neutral pH, low salinity hydrothermal fluids, which circulated over an area greater than 18 km2. Complex mineral zonation patterns result from variations in host rock permeability and composition, overprinting alteration possibly produced by thermal waters from surficial and peripheral parts of the hydrothermal system, and supergene weathering in the hyperarid environment. Upflow zones were focused along N-S and NE trending structures, producing crustiform quartz-adularia+carbonate veins. Fluid inclusion data indicate vein deposition from low salinity (

Jan 1, 2002

Rosebery Mine is situated on the west coast of Tasmania and is AustraliaÆs largest volcanic-hosted base and precious metals deposit (zinc, lead, copper, gold and silver). The milling operation has been producing zinc, lead and copper concentrates continuously for over 100 years. RoseberyÆs long life demonstrates the operation to be high grade, and high margin, capable of operating through several commodity price cycles. Paradoxically, throughout this long history the ælife-of-mineÆ as defined by proven and probable reserves has been short. Zinifex has demonstrated its commitment to discover the future of Rosebery with the growth project æProject HorizonsÆ. The aim of the project is to extend the life of mine beyond 2020, with an additional exploration expenditure of $19 million over three years. Despite the maturity of the deposit, early success has confirmed the potential with the discovery of new resources. Mine planning strategic studies are challenging established paradigms of mine production, throughput rates and metal cut-off grades. Discovering the optimal process rate for Rosebery, by examining the æHill of ValueÆ and underground mine optimisation is proving critical to the best exploitation of RoseberyÆs rich resources. The promise of finding a mine within a mine is being realised, with new lenses being delivered by exploration success and real grade/tonnage options optimised through dynamic mine planning. The future of Rosebery is co-dependent on these two areas of discovery. This ensures capital expenditure decisions are informed, to secure the next 20 years of wealth creation and beyond.

Jan 1, 2008

The application of cost updating with the aid of cost indices is reviewed with particular regard to the mining industry. Examples of applicable cost index series are included with values given for the last ten years. The compilation of the indices is discussed with consideration given to the possible sources of error inherent in their application to specific mining cost problems.

Jan 1, 1990

Experimentally determined and theoretically explained phenomenon of zonal disintegration of rock around the development working brings about the radical changes in existing ideas about the mechanism of interaction rock massive with engineering constructions.The essence of the phenomenon consists in the fact, that forming of non-elastic deformations zone goes on by way of more intensive deformation and destruction of rock simultaneously in several zones, covering partially or fully output circuit and divided by zones of destructed rock. Under the influence of change of massive strained-deformational condition of depositional rock an accidental deviation of zones of supplementary expansion and compression of rock from the previous positions take place. One can observe multiplicational change of the outline, size and form of all disintegration zones in the time within the area of the working influence at massive. This phenomenon was named "fluctuation of zonal disintegration of sedimentary rock around development working".

Jan 1, 1991