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Excavator output rates given in Makers' catalogues are sometimes based on favourable operating conditions. Mine operators and planners are more interested in the Effective Hourly Output in normal operation (Qe) a plant system can give hour by hour and year after year in a particular application. The number of hours mining plant will be available for normal operation will be less than the annual total of 8760 h. The number of the available hours which can be utilised at Qe will depend largely on the number and types of units in the plant system, the manners in which they are applied and the nature of the deposit in which they work. The emphasis herein is on continuous systems for deep stripping with BWE's as the primary excavator. Examples and suggestions are given for the annual hours at Qe for some BWE systems.

Jan 1, 1981

By J Thoma, W Skinner, W Stewart, R Smart

The acid neutralisation capacity (ANC) of rock sample containing significant iron carbonates and/or reactive framboidal pyrite can be a difficult parameter to determine. Results indicated that negative ANC results can occur if reactive sulfide minerals are present; and an over-estimation of ANC will result if significant Fe rich carbonate minerals are present during industry standard ANC tests. In this paper we investigate these problems. Results showed that a significant lag period may be needed (up to 432 hours) after standard Sobek ANC type tests of siderite for the complete hydrolysis of iron released from this mineral. This even occurred with standard industry modifications that included the addition of two drops of hydrogen peroxide. In this work we use a modified Sobek test that included filtering, and thence continued hydrogen peroxide addition until there was no subsequent pH drop, followed by back titration to pH 7.0. Results indicated that the ANC for the siderite (after zero hours) was immediately comparable to the ANC determined after 432 hours lag by standard Sobek type tests; and a calculated theoretical carbonate ANC. Investigations of coal waste samples containing significant framboidal pyrite indicated that standard Sobek ANC type tests can result in negative ANC values due to the oxidation of this reactive pyrite. Because sulfide acidity is already addressed by the MPA calculation, the inclusion of sulfide acidity as part of the ANC determination is effectively biased towards acid generation and thus positive NAPP values. Negative ANC values cannot be ignored or assumed to be zero as this masks any actual ANC available within the sample, which may possibly affect AMD categorisation. This sulfide acidity can be factored out using the quantity of S in the ANC digestion liquor and knowing the non-acid generating sulfate content of the sample prior to ANC testing. Results indicated that incomplete iron hydrolysis at the completion of the Modified Sobek ANC test is not only a function of iron carbonate dissolution, but is also related to the dissolution of Fe-sulfate salts, and the oxidation of reactive sulfides such as framboidal pyrite.

Jan 1, 2003

The rnunber of Cenozoic volcanoes which has already been found in China surpasses 600. An ancient Chinese tourist, Xu Xiake (1587-1641 in the Ming Dynasty), mentioned in his travel notes the volcanoes and hot 'springs in Tengchong, a country of the Yunnan Province, 400 years ago. In 1927, the geologist, Yun Zhanli, expounded generally on the recent volcano distribution in China. In the '70's, China not only accomplished aerial photography and produced topographic and geological naps covering the whole country, but also obtained a new understanding of the geographic distribution and process of development of the Cenozoic volcanoes through Landsat imagery; interpretation and ground verification, together with C14 isotope dating and analysis of volcanic rocks.

Jan 1, 1987

By B Crompton, A Berghorst, G Knox

Laboratory-based dynamic testing provides an invaluable tool in the development of rock bolts for use in highly stressed, burst prone rock masses. While in most cases the laboratory-based test method is not a direct comparison to an in-situ installation due to the purely axial loading and variations in boundary conditions, it does provide an indication of the performance of the tendon system under dynamic loading. The aim of the research described in this paper is to provide an understanding of the effect of the impact velocity of the impact mass during a laboratory-based dynamic test. Understanding the effect of boundary conditions of laboratory testing will improve Geotechnical Engineers understanding of the performance in an in-situ installation. In addition, due to the limited number of dynamic test facilities, an understanding of the effects of the boundary conditions will aid in the comparison of test results for different products from different test facilities. The research was conducted using an impact tester, whereby a known mass is raised to a known height defining the kinetic energy and velocity of the mass at the point of impact with the test sample after release. The impact velocity was varied between 2.7 m/s and 5.4 m/s, while the kinetic energy of the mass was maintained at 11.5 kJ. While a correlation between the impact velocity and strain rate of the system tested was established, due to the properties of the system tested, the range of impact velocity on which dynamic tests were conducted was insufficient to result in a considerable change in the average impact load, the cumulative proximal displacement and the cumulative maximum energy absorbed over multiple impulse. However, due to the reduction in the momentum of the impact mass the impact duration and displacement during each impulse in the series of impulses reduced. CITATION:Knox, G, Berghorst, A and Crompton, B, 2018. The relationship between the magnitude of impact velocity per impulse and cumulative absorbed energy capacity of a rock bolt, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 160–169 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By G Pizarro, O Miranda, D Rosales

In panel/block caving mines, large amounts of information are collected at the operations. This information includes grades and extracted tonnage, fragmentation, lithology, design of stopes and main infrastructure, geotechnical information, overbreak progress, seismicity, numerical modelling and many other mine variables. To improve the reliability of the production plan it is required to integrate the mine data into one platform. In this paper, the logic of a new technological platform is presented for analysis, modelling and design in panel/block caving mines. The platform includes an acquisition system for mine data and geotechnical information, a back-analysis module for calibrating statistical models and a module of visualisation of the results. The application and benefits of the platform is illustrated for mining induced seismic risk for panel/block caving mining operation. The platform can be used in the mine design and planning processes and is useful for reducing uncertainty in the mining business of panel/block caving operations.CITATION:Miranda, O, Rosales, D, Pizarro, G and Vallejos, J, 2016. Development of an integrated platform for the analysis, modelling and design in panel caving mines, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 237–240 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Hare S. M, Lumsdaine I, O&apos

Converter slag assaying 3.7 per cent Cu is produced by Mount Isa copper smelter at a rate of up to 180 000 tonnes per annum.Priority is given to the processing of ore, however concentrator capacity periodically exceeds that of the mine and the opportunity is taken to treat converter slag. It is processed in batch campaigns, typically through the Copper Concentrator, but the Hilton Concentrator has also been used. Slag and ore are kept as separate as possible, since each has an adverse effect on the flotation performance of the other.

Jan 1, 1993

The economic viability of many Southern African massive mining operations is threatened by excessive dilution. In many operations currently in progress, some stopes are experiencing as much as 115 per cent waste ingress reporting to drawpoints. This paper examines the magnitude, causes and types of dilution and presents a set of general principles for the control of dilution in massive stoping operations.

Jan 1, 2000

By Tukkimies M

During the late-1980s crawler-mounted crusher units established their position in the aggregates industry. Between 1986 and 1994 about 700 units were delivered to customers all over the world for surface operations, mainly in Scandinavia and central Europe. The crawler-mounted units are popular among smaller crushing operators because they are versatile and easy to move between sites. In large quarries the greatest benefit is obtained by combining a primary crawler-mounted crusher unit with mobile belt conveyors which eliminates the need for costly haulage by dump truck. Savings of up to 40 per cent in production costs prior to secondary crushing have been achieved. Today the environmental aspect in quarrying is assuming ever greater importance. Besides being costly the dump trucks are also the major source of dust and exhaust fumes within a quarry. A complete face crushing system consisting of a crawler-mounted crusher unit and mobile belt conveyors can be electrically driven and can be equipped with dust encapsulation and dust collectors. A mobile crushing unit is not a new idea. From the mid-1950s onwards the mobile and self-propelled units have been built equipped with crawlers, tyres or walking mechanisms, with weights usually of 500-1000 t. Due to their massive size these unit are not mobile in the same way as the today's mobile units. It is not feasible to move them more than a few times a year unlike today's fully mobile units which are often relocated once an hour. This means that the massive units can not continuously follow the production face and their loading always requires a certain amount of haulage. Today the mining industry is facing new challenges. With low mineral prices and high labour costs, increasing productivity is essential for survival. New standards are also being set for the labour safety and the environment. Large research programs have been launched to meet these challenges. However, technology which can partly solve these problems already exist and is only waiting to be introduced into underground applications as well - the mobile crushing unit followed by belt conveying. As in surface operations the elimination of truck haulage also brings considerable savings in operating costs in underground mines and reduces the amount of dust and exhaust gases generated. An additional benefit especially in underground applications is improved safety. In an underground mine most accidents are caused by moving vehicles.

Jan 1, 1995

By R Berry, J Lett, C L. Harraden

"In the past decade, increased processing capacity combined with precision robotics in high resolution spectrometers has resulted in a new generation of high-speed hyperspectral core logging systems. The application of these multisensor automated platforms provides a key advancement in the characterisation of metal resources. The development of this technology has allowed for comprehensive, drill core-based, mine-scale rock mass characterisation studies. Here we propose a new method for the extraction of parameters that seek to more accurately quantify ground conditions, including quantified rock mass rating (RMR) and the Rock Tunnelling Quality (Q) Index. Data inputs include rock quality designation (RQD), number of joint sets, joint roughness, joint alteration and joint spacing. Geologists and geotechnical engineers have historically collected these inputs by manually logging drill core. With automated core scanning technologies, these parameters can be estimated from the acquired image data and used to objectively calculate RMR and Q-index values for oriented core.Corescan is an automated hyperspectral core scanner that uses a 3D laser profiling system to measure the height of the surface of drill core. This technology allows for rapid core analysis to produce detailed fracture and rock condition data. Through an integrated geometallurgical approach, the proposed methodology will test the accuracy of joint measurement using the height profile Corescan data from oriented drill core. This will be combined with joint roughness and alteration mineralogy measured from the hyperspectral images to calculate the RMR and the Q-index continuously downhole. The values obtained can then be compared to the traditional, manual geotechnical log data. If the precision is sufficient, these techniques can then be applied site-wide to automate the collection and modelling of key ground condition classification indices across an entire deposit. Compared to the laborious manual geotechnical logging procedures that currently form the industry standard, utilisation of core laser profile data and high resolution red-green-blue (RGB) images provide an opportunity to collect large volumes of consistent geotechnical data, which can increase the efficiency and accuracy of deposit scale geotechnical models.CITATION:Harraden, C L, Berry, R and Lett, J, 2016. Proposed Methodology for Utilising Automated Core Logging Technology to Extract Geotechnical Index Parameters, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 119–124 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By P Mackenzie, S Askraba

Pyritic black shales present several challenges to mining operations due to their reactivity. The risk of predetonation of explosives in blastholes, spontaneous combustion of fractured rock and the generation of acid rock drainage must be managed for safety, operational and environmental reasons. At the Mt Tom Price iron ore mine there is a need to differentiate between reactive and non-reactive shale in order to assess risk and make decisions on materials handling. The current approach uses a combination of stratigraphic information and sulfur analysis of blasthole samples. The time taken for sulfur analyses can be a constraining factor on mine production. A new instrument developed by ANSTO Minerals overcomes some of the current limitations on material characterisation. The IOR MeterÖ measures the intrinsic oxidation rate (IOR) of samples of broken rock by circulating air through a sample and monitoring the oxygen concentration over time. The intrinsic oxidation rate is given by the rate at which oxygen is consumed per unit mass of sample, in units of kg(oxygen) kg-1(sample) s-1. Up to eight samples can be measured simultaneously and the turn-around time can be less than 12 hours. Initial trials of the IOR MeterÖ were undertaken at the Mt Tom Price mine in July 2004. The measured IOR of samples from a blasthole pattern spanning different geological layers containing black shale, correlated strongly with the expected reactivity of those layers. The correlation between position in the geological sequence (detailed stratigraphy) and IOR MeterÖ results were much stronger than that between stratigraphy and sulfur content. The new characterisation technique offers the prospect of improving the ability to identify and predict the behaviour of reactive black shales and to differentiate more precisely between different materials. Mine planning, operations, safety and environment all stand to benefit from the success of further trials of the technique.

Jan 1, 2005

By A Purton, C Taylor, E Conroy

The spatial modelling of geometallurgical domains is an important step in the characterisation of an ore deposit allowing for the quantification of various rock types, their differing rock properties and the overall value of a project. The traditional approach to modelling such features is through the use of deterministic models, where a single estimate of the extents and structure of the ore deposit is mapped out by geologists based on available data and their interpretation of the geological processes. Any uncertainty in the layout of different domains is not accounted for and heterogeneities of chemical and physical properties of the orebody are likely underestimated. Spatial machine learning techniques can be used to derive geometallurgical categories, or classes, from multiscale, multiresolution and high dimensional measured rock properties. Subsequently, geostatistical simulations of these classes can be applied to obtain multiple equiprobable realisations that define the layout of the geometallurgical classes at unknown locations between boreholes, or domains. In-turn these realisations can be used quantify the uncertainties in the location of boundaries between different domains. The development of a workflow for defining geometallurgical domains and later geostatistically simulating them across the Orebody H; a complex stratabound Bedded Iron Ore deposit located in Western Australia’s Pilbara region is demonstrated. This could be used to identify zones of high uncertainty where collection of additional data might help mitigate or minimise risks and in turn improve forecast production performances.

Mar 22, 2022

By K Brand, M J. Ind, M Rynhoud

Water management at a tailings storage facility (TSF) presents one of the major risks to the safe performance of the facility. International and domestic dam safety guidelines assess a dam’s hazard category based on the consequences of a dam failure and the subsequent downstream damage to the environment and communities.Often a rigorous risk assessment is undertaken during the design stages to identify and control hazards associated with water management through life-of-mine (LOM) phases. However, as experienced during the recent downturn in commodity prices, early closure of a mine can occur rapidly and unexpectedly. Although guidelines such as the Australian National Committee on Large Dams Incorporated (ANCOLD) recommend that one of the key objectives of integrated TSF planning is to ‘plan all phases of a tailing dam’s life to ensure adequate storage capacity including early closure ’ (Australian National Committee on Large Dams Incorporated (ANCOLD), 2012) this is often overlooked by owners who are focused on fulfilling the mine’s potential and early closure is not on their radar.CITATION:Ind, M J, Rynhoud, M and Brand, K, 2016. Life-of-mine spillway strategy – managing risk associated with surface water at a tailings storage facility, in Proceedings Life-of-Mine 2016 Conference, pp 209–211 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By D Kent

The introduction of digital technologies into the underground mining industry, in both coal and hard rock mining, has enabled many high bandwidth applications to be adopted by mines.Digital networks based on 802.11 b/g/n open Wi-Fi standards allow for many applications to be run over a single communication backbone. One important application has been tracking personnel and equipment via RFID tags. This tracking application has in turn formed the basis of a Proximity Detection System (PDS) or Collision Avoidance Systems (CAS). The paper discusses the growth in digital technology as the communication backbone in underground mines which has allowed the ‘convergence of technologies’ that has been occurring in the general business world to be available to underground mine operators. Then the paper will focus on the use of the technology in the increasingly important are of risk control around mobile plant underground. The specific use of digital devices for proximity detection, in both hard rock and coal mines, to provide a system that can deliver an additional level of control to the risks associated with people-vehicle interactions underground is discussed. The initial implementation of PDS in the hard rock mining environment is based on two zones of detection, required for large and relatively high speed vehicles. Information will include:•the principles of the underlying technology,•installation learnings and effectiveness, and•change management methodology and issues.The most recent development to integrate Mine Site Technologies (MST) PDS with Frederick Mining Controls’ HazardAvert® System to extend the overall Proximity System’s functionality in hard rock mines and for use in coal mines is overviewed.

Mar 21, 2011

By T Roesch, M Neurohr, S Stratton

"Dwindling commodity prices are forcing today’s mining operations to increase output. Sometimes the solution is to upgrade the existing infrastructure; however, in most cases it has to be achieved with the same or reduced workforce and with the same equipment capacity through improved process efficiency and higher uptime.Measure, Manage and Improveis the mantra for this years’ Mill Operators’ Conference and while this in most cases relates to the above process efficiency, Siemens has set its focus on the availability and uptime aspect since unscheduled downtime is one of the biggest threats to any grinding operation. Pinion misalignments, resonance, unbalance and bearing and gear meshing faults in geared trains, as well as long-term changes in the condition of the mechanical components or structures and auxiliary systems in gearless systems are the main reasons for unscheduled downtimes in today’s mill drive trains. Our paper outlines the efforts that have gone into adapting conventional condition monitoring methods in conventional, pinion driven mill drive trains as well as gearless systems to capture the gradual deterioration of wearing parts or structural changes in the drive train not only on fixed speed application but also on variable speed applications with multiple operating points. The paper further explores the use of condition monitoring systems as a tool to assess spare thermal motor capacity to potentially push equipment beyond its nameplate rating, along with the process that was followed to correlate measured frequency spectra and envelopes to ambient and load data to understand the kinematics of the drive train.Citation:Neurohr, M, Stratton, S and Roesch, T, 2016. Advancements in Condition Monitoring on Mill Drive Trains for Proactive Maintenance and Early Fault Detection Purposes, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 263–272 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By S Ellis

In January 2008 Chirano Gold Mines Limited committed to expansion of the Chirano Gold Project from its existing design capacity of 2 Mtpa ROM ore to a new design value of 3.5 Mtpa. In addition to increased throughput, the design had to contend with increasing ore hardness and competency, while at the same time make cost effective use of existing equipment with minimum disruption to existing production. The solution adopted involved some novel approaches including tertiary crushing and operation of the SABC circuit in overflow ball mill mode and parallel elution with a common acid wash column. This paper describes the approach taken to the design of these elements to achieve a cost effective and safe capacity expansion.

Aug 8, 2011

The revival of the mining industry at Captain's Flat after a long period of years of inactivity has attracted attention to the importance of the ore-deposits of that field as potential sources of supply of lead and zinc. Mindful of the necessity for taking stock of the State's mineral resources, the Department of Mines of New South Wales as part of its programme of geological investigation, carried out a survey of the oredeposits and associated country rocks during 1938 and 1940.Surface geology was mapped in detail and all available exposures were examined and logged. Unfortunately, and this condition militates against the formulation of conclusions because of insufficiem.t data, some of the older workings, notably in Keating's Section, were inaccessible and the logging of levels and stopes is by no means as complete as could be desired. However, with the progress of development and exploration, further information of geological value will come to hand for incorporation in supplementary reports. It may be expected that, under such circumstances, modification of certain statements herein expressed may be necessary but it is not anticipated that any vital alteration will be occasioned.Within the State of, New South Wales, Captain's Flat ranks second to Broken Hill as a pqtem.tial producer of lead and zinc. In addition, large quantities of iron pyrites are available for the manufacture of sulphuric acid which finds application in the superphosphate industry.The mines are now controlled by an operating company known as Lake George Mines, Ltd., incorporated in New South Wales, the parent organisation being the Lake George Mining Gorporation Ltd., registered in London.Over £600,000 has been spent by the Company in exploration, mine development, surface plant, housing and water 'conservation, while the State' Government constructed a branch railway from Bungendore at a cost of £200,000. The various activities consequent upon these development and construction programmes and the prospect of employment in the industry has led to a rapid increase in the population of the township.The State, generally, has benefited to the extent of a substantial contribution to the relief of the unemployment problem, and it is hoped that reasonable permanency will be assured to some hundreds of workers for many years.

Jan 1, 1941

By J Jones

A common problem in the mining industry is that company exploration groups operate in relative isolation to the rest of the company; resulting in poor knowledge transfer (Qureshi and Briggs, 2006) and often priority conflicts with mine geology, operations and project departments. In recognition of this problem, Newcrest created a Minerals Division responsible for stewardship and governance of mineral assets across the value chain from reconnaissance to rehabilitation. It was recognised at an early stage that effective collaboration both internally and externally would be required to improve decision making, deliver faster cycle times and improve governance.Collaboration in companies is generally associated with the introduction of new IT functions. However, modern IT-based collaboration systems and practices are relatively simplistic compared to the long-standing practices associated with collaboration and knowledge management in science and engineering disciplines such as geology and mining.The authors of this paper have started a trial of a 12-point plan for effective collaboration, which recognises that significant efficiencies can be gained and barriers to future success removed if more effective collaboration can be achieved between science and engineering divisions in a company along with external professionals and with the collective intelligence (Tapscott and Williams, 2006) of the outside world. To meet growth aspirations some companies, like Newcrest Mining Ltd, are adopting this comprehensive, step change approach by moving from a closed model the isolates mine geologists to an open and collaborative model that uses IT visualisation systems strategically. The paper describes how an open model provides people with the right work environment and the right information at the right time, which will help individuals and workgroups to work more collaboratively day-to-day. The aim is to achieve speed, focus and mitigate risk through an environment where everyone and anyone can contribute effectively (Cisco, 2008).

Aug 22, 2011

By K Devencorn

The development of robust, economical transport infrastructure has been identified as a key driver to sovereign economic growth. Notwithstanding the value of undeveloped mineral resources, unless they can be brought to market they are of little value. Within a global context, the continent of Africa probably faces one of the most significant transport driven economic development programs as countries strive to unlock their much sought after resources.The UN’s Africa Review Report on Transport (United Nations Economic and Social Council, 2009) provides an excellent context for the issue facing African countries and the potential for investment in transport to solve many of the intrinsic problems they are confronted with. With little exception, economic development in Africa is very likely to be driven ‘off the back’ of transport development – and more specifically from heavy-haul rail as a means by which economic wealth can be derived from export of the continent’s vast natural and mineral resources to the world. The report found:transport is a key driver of economic development and poverty reduction;road transport is the most dominant mode in Africa;the ‘Cost to Market’ of African goods is hampered by the reliance upon road transport;the cost of road transport is not just economic – 19 per cent of the world’s road fatalities were recorded on African roads;African railways are seen to be disjointed and under-utilised;Africa’s ports are key to export trade - yet only six ports (three in Egypt, and three in South Africa) handle about 50 per cent of the continent’s total container traffic;the cost of transport is increasing making African trade even less competitive; andsignificant negative impacts of Africa’s reliance on road transport – health, and greenhouse emissions.We understand that mining the resource is only part of the solution – it has to be put to market at a competitive landed cost.Most African countries face huge costs associated with transport development and ongoing operation – in many cases beyond their available resources.The Australian rail industry has faced and solved many of these challenges.

Nov 22, 2011

Utah Development Company operates a mine at Blackwater with a present annual production of 4 000 000 tonnes of coking coal. Mineable seams outcropping on the company's lease are part of the Permian Mammoth Rangal Coal Measures. Current operations are based pre- dominantly on the Main Lower seam. Coal quality variations occur along the seam strike, in the direction of seam dip, within the seam plies and in isolated anomalous areas. Raw coal of non-specification quality is washed to reduce ash and sulphur and to improve the free swelling index. Raw coal meeting specification quality is sent directly to product, by-passing the washplant. Careful attention to mining, coal preparation and product blending is necessary to ensure that the combined product meets specifications.

Jan 1, 1974

Transport infrastructure constitutes, since always, an essential link between regions, countries and continents, for economical, commercial and human purposes. Permanently growing mobility needs, which are encountered in the whole world, lead to a more and more clear necessity to increase and modernise these transport infrastructures, as well in quantity as in quality, for all transport modes, and for all what is able to be transported, from people to consumption goods and energy. With only very few exceptions, transport infrastructure achievements have for long been the concern of the sole public authorities, at the various levels, which put them, mostly free of charge or at very low cost, at the disposition of the user or the customer.

Jan 1, 1999