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By Y Xiao, C Lei, C Shu, W Wang, K Wang, J Deng

To investigate the effect on coal spontaneous combustion with high geo-temperature, an experimental apparatus was developed to measure characteristic parameters of two kinds of coal samples at different temperatures: one was 40°C (G coal sample) and the other was a rising temperature from room temperature (C coal sample). Based on the relationship between CO concentration and the temperature variation, a calculation model of the apparent activation energy of coal was established. The results indicated that the oxygen consumption rate, the generation rate of CO and CO2, and heat release intensity of G coal sample were higher than C coal sample. This trend was more and more obvious as the temperature increased. Furthermore, the apparent activation energy of G coal sample was lower than C coal sample, especially at low temperature stage, which demonstrated that the more the oxidation and exothermic reaction of G coal sample was enhanced, the less energy was required to break the barrier of oxidation reaction. Under the same condition, the speed of oxidation reaction was faster for the coal in the high geo-temperature environment, which was more liable to spontaneous combustion.CITATION:Lei, C, Deng, J, Xiao, Y, Shu, C, Wang, K and Wang, W, 2017. The effect of high geo-temperature environment on spontaneous combustion – an experimental study, in Proceedings Australian Mine Vent Conference 2017, pp 137–142 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By J-S Han, J-M Yao

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Shagou deposit is located along NE-trending faults within the high-grade metamorphic basement of the Xiong’er Terrane in the Qinling orogenic belt. It is a large Ag-Pb-Zn deposit hosted in the Taihua Supergroup and has proven reserves of 1.54 Mt of ore with grades of 767 g/t Ag, 13.24 per cent Pb and 4.31 per cent Zn. The hydrothermal ore-forming process can be divided into early quartz-pyrite, middle quartz-polymetallic sulfides and late quartz-carbonate stages. Four types of fluid inclusions (ie pure carbonic, carbonic, pure aqueous and aqueous) can be distinguished in quartz. Fluid inclusion, hydrogen, oxygen and sulfur isotope systematics indicate that the ore-forming fluids are initially deeply sourced metamorphic water with meteoric water gradually mixed in the later stages. Sulfur isotope data show that the ore-forming fluids originated from both the Taihua Supergroup and the sedimentary successions of the Guandaokou and Luanchuan Groups (CSC) located to the south of the Machaoying Fault. A genetic model of the Shagou deposit is proposed as follows: CSC subducted northward along the Machaoying Fault beneath the Xiong’er Terrane during the Mesozoic collision between the North China Craton and South China Block. Subsequent dehydration resulted in the devolatilisation of fluids rich in CO2. These fluids migrated upwards, reacted with the Taihua Supergroup and formed the Shagou deposit.CITATION:Han, J-S, Yao, J-M and Chen, H, 2015. Fluid inclusion and isotopic constraints on the mineralisation of the Shagou Ag-Pb-Zn deposit, Henan Province, China , in Proceedings PACRIM 2015 Congress, pp 615–618 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

The methods and equipment developed and used at the Mount Isa mine to obtain samples of uncemented hydraulic fill lying above major horizontal pillars are described. From existing underground development, samples were obtained at distances up to 50 m, of which up to 30 m was through hard rock. Samples were used to predict fill behaviour as it affected mining security during recovery of the pillars.Specialized equipment for difficult sampling situations and also other sampling exercises are described.

Jan 1, 1976

By R van Berkel

Regional synergies concern the capture, recovery and reuse of by-products, water and energy between industrial operations in close proximity. The Centre for Sustainable Resource Processing (CSRP) undertakes applied research to further advance regional synergies in the Kwinana Industrial Area in Western Australia in order to achieve greater efficiencies in water, energy and materials consumption and reduction in waste and emission generation. The Kwinana Industries Council (KIC) and its member organisations recognise water consumption and disposal as key environmental issues. Some 30 companies in Kwinana consume a total of more than 35 000 ML/yr of fresh water. Over the past years significant progress has been made towards the reduction of water consumption and improvements in effluent disposal. As part of the CSRP Kwinana Synergies Project, water balances for the ten major water consuming companies have been completed, including workshop sessions with company staff on water synergy opportunities. This work resulted in a set of synergy opportunities which are currently being pursued. In parallel to the Kwinana project, the CSRP has commissioned a supporting project that delivers a toolkit to guide a more targeted and less resource intensive way to identify feasible water synergy opportunities. One of these tools focuses specifically on water, and takes count of input and output water flows within a given industrial area to deliver listings of prioritised water synergy opportunities. This paper discusses the water mapping and workshop approach taken in Kwinana and its outcomes, which are to identify and evaluate water synergy opportunities. The results from the trial application of the developed Regional Eco-Efficiency Opportunity Assessment Toolkit are also presented.

Jan 1, 2006

By P Breuer, A Simons

The sulfidisation, acidification, recycle and thickening (SART) process is currently being used at NewcrestÆs Telfer Gold Mine to recover cyanide and copper from the cyanidation tails of the pyrite concentrate carbon-in-leach (CIL) process. While the process has been effective at attaining high recoveries of cyanide and copper, the Telfer SART plant has experienced higher than expected sulfide additions to achieve these recoveries. This paper details the results of surveys on the Telfer SART plant, which show that residence time appears to be causing the high sulfide consumptions. The paper also details the results of laboratory scale experiments which confirm the observed residence time impact during the acidified stage of SART.CITATION:Simons, A and Breuer, P, 2013. The impact of residence time on copper recovery in Telfer Gold MineÆs cyanide recycling process, in Proceedings World Gold 2013 , pp 189-196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

Green policies have gained momentum since the 1972 Stockholm Environment Conference. The environmental movement has influenced political initiatives both in New Zealand and abroad. Governments and international institutions have addressed local, regional and global environmental issues with varying degrees of success. New Zealand so far has not supported the United Nations' call for sustainable development in a,consistent manner.New institutions and new rules for resource management mean there are opportunities to look after the land in different and more ecologically sensitive ways than has happened in the past.The increasing influence of regional councils in resource management planning will have important implications for mining and mineral exploration. These trends are discussed and possible future events outlined.

Jan 1, 1990

By Oxenford R. J

An important rutile-ilmenite-zircon bearing sand deposit was discovered by local farmers at Eneabba, 300 km by road north of Perth in 1970. These heavy minerals occur in a series of ancient strandlines and associated dunal deposits at elevations from 85 m to 170 m above the present sea level and are situated,30 km inland. The strandlines were deposited on wave- cut platforms in an ancient bay bounded by Mesozoic sediments during a series of regress- ions from a high sea level, probably during late Tertiary or early Pleistocene times. The immediate source of the heavy minerals in the Eneabba deposit is a widespread low content of those minerals in the nearby Mesozoic sedi- ments. The high-grade southern portion of the Eneabba deposit has been closely drilled and is now being prepared for production by Allied Eneabba.Pty. Ltd., a subsidiary of Allied Minerals N.L. This part of the deposit is 11 km long and up to 2.5 km wide. It is characterised by little or no overburden and the average depth of mineralisation, bounded by a 2.5 per cent heavy mineral cut-off, is 12 m. The water-laid strandline deposits at the base of the mineralisation are generally high grade, ranging from 20 to 60 per cent

Jan 1, 1973

By D Horacek, I K. Sheppard

Ok Tedi is in a period of transition. By 2008 mill feed will consist of higher levels of high-grade but metallurgically challenging skarn ores. Additionally, the Taranaki pit will start production in 2008 along with the start-up of a new pyrite concentrator. Taranaki ores are very high in sulfur. Sulfur is captured in a pyrite concentrate prior to tailing entering the Ok Tedi River. These and other complex scheduling issues will need to be resolved over a critical three-year period. With these requirements in mind, Ok Tedi contracted AMC Consultants to develop a custom version of the Life of Business Optimisation System (LOBOS¬) to assist medium-term production scheduling at Ok Tedi. LOBOS utilities enable Ok Tedi planning engineers to:import polygon-based reserve data (Blast Masters) from MineSightÆs Interactive Planning Tools (IP Tools); graphically construct block sequencing and material flow constraints; edit constraints defining standard scheduling, processing and financial relationships; define dump and stockpile attributes; and assign capacities to production systems, plants, dumps and stockpiles. LOBOS converts Ok TediÆs production scenario into a mixed integer program (MIP) and submits the resulting model to IlogÆs Cplex MIP Solver. The Solver seeks an optimal production schedule that maximises net revenue per mill hour while meeting all constraints. This paper introduces Ok Tedi and its production requirements and relates these requirements to the facilities developed for an Ok Tedi version of LOBOS.

Jan 1, 2007

A Presidential Commission of Enquiry into the conservation of South Africa's coal resources was appointed in 1970. This Commission, in co-operation with the Chamber of Mines of South Africa, established a national inventory of South Africa's in situ and extractable resources and reserves of coal of various types and grades by several mining methods. South Africa's future demand for coal by all market sectors and the specifications of coal required, were also established by means of econometric models. A comparison of potential supply and anticipated demand indicated serious defi- ciencies of certain types of coal and the need for the conservation of others. This paper describes recommendations for alternate strategies for the optimum utilization of available resources. Con- sideration was given to various policies relating to pricing, exports, taxation and incentives, and to the possibility of the substitution of higher grades of coal by lower grades. The steps so far taken to develop a national coal policy in South Africa are described.

Jan 1, 1977

Many mining companies, by their remoteness of location from source of power, have to generate their own power and must experience the same problem that had to be met when deciding to increase the capacity of the power station. At present the Company is treating approximately 54,000 tons of ore mined per month, and the present shift average load. is approximately 8,500 kW. at 0.8 power factor, generated at the power plant, the observed peak load being 10,500 kW.It is proposed to increase the tonnage of ore treated to include 36,000 tons of copper ore, in addition to the present 54,000 tons of lead ore. The average load is estimated to be approximately' 16,000 kW. with a peak load of 17,500 kW. The estimate provides for power of 1,000 kW. to be supplied to the north end leases in the next 12 months, also for increased ventilation in the mines.There are installed in the main power station three turbo alternator sets each of 5,000 kW.; normally two sets are run in parallel and one set is a standby unit. A 12,500 kW. set is being installed and proposed loading with the increased tonnage will require the 12,500 kW. set and one 5,000 kW. set, or alternatively, the three 5,000 kW. sets When the 12,500 kW. set is down for service. When the original plant was installed some 25 years ago, the switches selected and installed in the main 3,300 V. power plant switchboard were rated at 150 MVA and the substation distributing centres located at the surface of the mine, in the mill, and in the smelter, were purchased as having a rupturing capacity of 100 MVA, and the stator...

Jan 1, 1953

Separation of Minerals Using Electrical Fields The mineral processing industry requires alternative separation techniques to help deal with rising energy costs and decreasing ore grades. Dielectrophoresis is one possible technology. It uses non-uniform electrical fields to separate particles on the basis of their permittivity. In order to determine its viability, the dielectrophoretic force was measured for individual chalcopyrite particles in ethanol. The measurements were made by attaching the individual particles to glass fibres and measuring how far they were deflected by a non-uniform electrical field. Six sizes of chalcopyrite particles were tested and the force was found to increase as a function of particle radius cubed. The particles were also positioned at different points in the field in order to determine the effect of the electrical field gradient. The force was found to increase with the inverse cube of the distance from the centre of the particle to the pin electrode. With the effect of these parameters fully characterised, the single particle test cell can be used to determine the permittivity of single particles of various composition.

Sep 13, 2010

By D Mee

The Western Mining site at Olympic Dam, near the community of Roxby Downs in South Australia is one of the largest orebodies of its type in the world. It contains known reserves of over 10.6 M tonne of copper, with economic secondary metals including uranium, silver and gold. In 1996, an expansion project was commenced to increase mine production approximately threefold, to produce 200 000 tonnes pa of copper, 4600 kg pa of uranium oxide, 3600 kg pa of gold and 50 000 kg pa of silver. This expansion included both underground mining and surface processing investment. Because of the scale of operations, it was decided that ore should be transported underground by a railway system. In July 1997, ALSTOM Automation and Control Limited (then Cegelec Australia Limited), was awarded the contract to deliver a control system to manage and automate the rail haulage system for Western MiningÆs Olympic Dam Mine, as part of this major upgrade and extension project. This paper explains the overall design and the approach taken to implement route selection, route locking, train interlocking and track topology using normal industrial control equipment such as Programmable Logic Controllers. Included is a discussion of how this automation has improved the productivity of the haulage system by more than 15 per cent.

Jan 1, 2000

Laboratory electrical resistivity measurements of rocks are reviewed. Inductive and galvanic methods are discussed together with the ten important experimental factors which should be considered in an investigation.These experimental factors are electrodes, sample preparation, measurement errors, temporal current variations, current density, frequency, electrolyte composition, electrolyte saturation, pressure, and temperature.

Jan 1, 1969

By J de Witte

When used in suitable ground conditions, rock bolts can have advantages over other permanent tunnel lining solutions. Permanent rock bolts offer flexibility in tunnelling profile and rapid rock bolt installation can enable time and cost savings. There are also disadvantages when considering the suitability of rock bolts for permanent support installations. These generally concern achieving the specified durability requirement over the specified design life. By investigating alternate approaches to rock bolt installation, quality assurance (QA), monitoring and design life it may be possible to alleviate some of these concerns.The design and construction benefits that can be realised through the use of rock bolts are primarily related to reducing project program time. This time reduction could be realised if rock bolts are considered as a permanent solution, with the installation being completed as a part of the primary excavation cycle. Any reduction of the program could allow direct and indirect cost savings and in the case of a major project, allow the revenue stream to be realised earlier.Currently ambiguity exists where the treatment of rock bolts as permanent support components is inconsistent with that of (often identical) ground anchors, as utilised in stabilising cut and cover structures. The ground support design process, implementation and testing are generally similar, though the acceptance of rock bolts as long-term support elements is treated differently to ground anchors in technical specifications.This paper discusses some of the benefits available through the use of rock bolts. It offers different solutions to the concerns surrounding durability, including alternate approaches to installation, Quality Assurance practices and monitoring solutions. The selection of an alternate design life is also investigated as another means of alleviating concerns around long-term durability. The paper will also provide an indication of savings that could be expected through the use of rock bolts as part of a long-term support system.

Mar 8, 2011

By A Moreira, A B. De Souza, S Latchireddi, E Faria

Material transport plays a significant role in the efficiency of horizontal grinding mills - autogenous (AG)/semi-autogenous (SAG)/ball mills. The magnitude of benefits that can be achieved with efficient material transport in AG/SAG mills has been demonstrated in a greenfield milling operation at Mirabela MineratpoÆs SantaRita Nickel operation located in north eastern Bahia in Brazil. This grinding circuit was commissioned in October 2009, was designed as a typical SABC circuit to grind 4.6 Mt/a (575 t/h) to produce a P80 of 125 ¦m with ten to 12 per cent ball charge in the SAG mill. However, it has been operating as an ABC circuit without any grinding media in SAG mill. The nameplate design capacity was achieved in few days and was gradually increased to an average of +800 t/h, still operating in ABC mode. The Santa Rita grinding circuit consists of one 30 ft + 15.4 ft 8.5 MW SAG mill fitted with Outotec patented Turbo Pulp Lifters (TPLÖ) in closed circuit with a HP400 short head pebble crusher and one 20 ft + 28.4 ft 5.5 MW Ball Mill in closed circuit with a Warman cyclone cluster fitted with 10 + 26 in CAVEX cyclones. This paper examines the comminution design process, operating philosophies, experiences, post commissioning optimisation and future development works. Evaluation of the milling circuit performance relative to the design criteria is also discussed.CITATION:De Souza, A B, Latchireddi, S, Moreira, A and Faria, E, 2012. Application of turbo pulp lifter in greenfield operation - Mirabela SantaRita nickel operation, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 53-58 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By P J. Hawke, M F. Flis

The Hamersley Basin of Western Australia holds significant tonnages of detrital iron deposits. Formed by a cyclic weathering and eroding sequence of nominally barren banded iron formation, they may form rich proximal accumulations of iron cemented gravels distal from any obvious hard-rock iron mineralisation. While generally small, they nonetheless represent excellent economic targets as they are near surface and easy to mine. The relatively high density of iron detritals, when compared with their sedimentary hosts, makes the gravity method the primary method of exploring for these blind deposits. Identification of possible trap sites is used as a precursor to gravity surveying, with magnetics used as an ancillary method prior to drilling. Application of the gravity method in this terrain is not straightforward. Detrital trap sites are best developed next to the spectacular cliffs that form the range fronts to the Hamersley Ranges. Precise terrain corrections and use of first vertical derivatives are routinely applied to gravity data in an effort to map every possible gravity high that may reflect the presence of a detrital accumulation. Extensions to Hamersley Iron Pty LimitedÆs BS2D deposit were discovered by the routine application of gravity. This methodology has been used to create a model by which exploration for detrital deposits continue to the present day.

Jan 1, 2002

By B D. Saffron

In 1983, open cut coal mining operations were suspended at the Tent Mountain coalmine, located in Alberta, Canada in an area called Crowsnest Pass. Montem Resources (‘Montem’), an Australian mining company, purchased the asset in 2016. They conducted several drilling campaigns and undertook environmental monitoring with the intent to restart operations. In 2020, Montem completed a Definitive Feasibility Study, which indicated a mine life of more than 14 years.

Aug 2, 2023

By R Lethlean

The mining industry in its drive to optimise equipment use and minimise cost simply to remain profitable in an uncertain commodity market needs to develop a greater understanding of equipment capabilities and cost. The factors influencing mobile equipment fleet cost and performance commence at the time of mine planning and continue to exert an influence over the life of the mine. These factors must be understood at the early stages of any operationÆs planning process as they continue to impact both positively and negatively on fleet performance and operating cost throughout the life of the mine. The key factors examined in this paper include: grades; rolling resistance; fragmentation and truck loading.

Jan 1, 1998

By S Warden, T Neville, P Leckie

At its simplest, the classification and characterisation of an orebody is a matter of Where, What and When. Where and with what spatial resolution are measurements taken, What properties are measured, and When are the data acquired, processed, and delivered to create the most value. This paper delves into how existing and near-term advances in measurement technologies, field automation, and whole-system-digitisation are combining to open new routes for mine and exploration productivity improvement. Commencing when the initial exploration hole is dug, the advancement in deployment of survey technology—from expert-operated, to driller-operated, to driller-integrated—is used to demonstrate a template for adoption of higher technology measurements. We then introduce and discuss the multi-use measurement as offering outsized returns from a single measurement run, highlighting two new technologies that acquire rock strength while drilling and downhole assay data as examples. For rock strength, we highlight a novel approach to determining Uniaxial Compressive Strength (UCS) while drilling, its relationship to and advantages over Mechanical Specific Energy (MSE), and how it offers utility to multiple downstream processes. For downhole assay, we detail how a back-tophysics approach to Pulsed Fast and Thermal Neutron Activation (PFTNA) analysis offers significant advantages over other measurement methods and earlier implementations of PFTNA, generating a rich data set that can significantly extend and improve the information on which mining decisions are made. Finally, we discuss the possibilities enabled via optimising data delivery, collection, and curation— noting a fundamental limitation of historical systems and exploring the possibilities that will be unlocked by soon-to-market solutions that better enable Orebody Characterisation data to (virtually) move in space and time with rock material post-blasting. Ultimately, the value of optimising the Where, What, and When from point of measurement to the moment it generates maximum value will create greater life-of-asset production for a lower cost and energy input.

Sep 1, 2024

The paper discusses the special mixing requirements for Metallurgical Plant Design and outlines the problems associated with the agitation in Mineral Processing Industry today. It also covers new applications such as state of the art large leach tanks and backfill for deep mining.

Jan 1, 2004