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With the continued drop in export coal prices (as measured in US$) delivered to the Pacific Rim market, and a fixed annual 12 per cent increase in overburden, Usibelli Coal Mine Inc was faced with the need to reduce mining costs substantially or else forfeit its foreign coal contractual commitment which amounted to about half of annual mine output. Management made a difficult and fortuitous decision to proceed with an engineered plan to switch from a two seam, extended bench dragline operation to a two seam, cast blast and spoil side operation. While down-sizing and cut-backs became the rule in all departments of the mine, the drilling and blasting budget was more than doubled. Most will agree that this is contrary to what usually happens when a mine is faced with down sizing. The more common scenario would have management target the drilling and blasting budget for decrease as a first priority to cutting cost, and then later witness a decrease in equipment performance leading to an increase in the production cost per tonne. Although Usibelli Coal Mine more than doubled its annual drilling an blasting budget three years ago, the overall stripping cost has be, reduced by more then 37 per cent.

Jan 1, 1995

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 S Jeon, K Aikawa, M Ito, A Kusano, I Park, N Hiroyoshi

In mineral processing of complex sulfide ores containing copper (Cu), lead (Pb), and zinc (Zn), flotation has been commonly used. Typical Pb mineral in the ores is galena (PbS), while some types of the ores contain anglesite (PbSO4). This article reviews our recent studies on the effects of coexisting PbSO4 on the flotation of complex sulfide ores, and a method to suppress the floatability of sphalerite (ZnS) in the presence of PbSO4 was proposed. Comparison of flotation experiments for different types of model samples showed that PbSO4 makes the separation of Zn from Cu difficult; that is, for the model sample containing PbS without PbSO4, Zn could be separated from Cu, while when the model sample containing PbSO4, Zn was recovered together with Cu as froth. Solution analysis and thermodynamic calculation suggested that Pb2+ was released from PbSO4 and reacted with ZnS to form PbS, acting as an adsorption site for the flotation collector, xanthate. This would be the main reason for high floatability of ZnS in the presence of PbSO4. As a method to suppress ZnS floatability for the ores containing PbSO4, a pre-treatment of the ores to remove PbSO4 prior to flotation was proposed. The results of model experiments using mixture of ZnS and PbSO4 showed that ~97 per cent of PbSO4 was dissolved within 30 minutes of pretreatment using ethylenediaminetetraacetic acid (EDTA) as extractant, and thus ZnS floatability was markedly suppressed. Moreover, Pb2+ extracted from PbSO4 during the pre-treatment could be recovered as zero-valent Pb by the cementation using zero-valent Fe as a reductant. The details of ZnS flotation in the presence of PbSO4 and the effects of the pre-treatment are discussed based on the results of surface analysis like XPS.

Aug 24, 2022

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

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 C M. Côte, S Worden, K Svobodova

Mines in Queensland are transitioning to the progressive rehabilitation and closure plan (PRCP) framework. Mine operators are required to select and justify appropriate and viable post-mining land uses (PMLUs) following consideration of the surrounding landscape, community views and the objectives of local and regional planning strategies. The new approach offers opportunities for considering innovative PMLU options and collaborative use of post-closure mine assets, such as infrastructure (power, road/rail, buildings), dams and residual voids. Consideration of regional planning strategies will require a shift in thinking as mine closure is regulated and planned on an individual site basis and selection of PMLUs are commonly considered from this perspective. Planning at regional rather than site-specific scale offers strategic advantages, including the ability to align PMLU selection with the regional context and stakeholder aspirations (which could foster sustainable outcomes); address cumulative environmental and socio-economic impacts; consider options that are only viable at scale (ie across larger geographic areas); establish more extensive and connected ecological habitat corridors; reinstate larger expanses of functional agricultural land; and optimise regional resources (Hattingh, Williams and Corder, 2019). This paper presents the findings from a multidisciplinary project that identified PMLU options within Queensland’s four mining regions: the North-west Minerals Province, North Queensland, Bowen Basin and Clarence-Moreton and Surat Basin (Figure 1). To enable spatial analysis at the appropriate scale and to accommodate geographic diversity, North Queensland was divided into three geographical ‘focus areas’ – Weipa, Charters Towers and Tablelands. Delineation of the areas captured most of the mines within the wider region as well as regional characteristics and features.

Aug 2, 2023

By Burman B. C

This paper describes studies into two particular aspects of the Lochiel deposit which formed part of feasibility level geot2chnical and hydrogeological investigations for proposed open cut mine development. The two aspects were depressurisation of thick beds of silt located through the profile and the determination of characteristics and origins of soil structure and their effect on pit stability. The studies were very detailed and multi disciplinary and highlight the integration of geology, geotechnics, hydrogeology and mining that is required for mine development studies. It is considered that as more marginal deposits are developed throughout the world the demands for efficient economic mining together with in- creasing scales of operation will require simi- lar types of studies. As such the studies pre- sented herein are likely to be a forerunner to a,emerging trend for development of open pit mines in difficult ground and water conditions.

Jan 1, 1986

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

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 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

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

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 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 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 W Shamu

The mechanical properties of rock samples of identical lithologicalcomposition may vary significantly due to existence of materialdiscontinuities. Laboratory tests were carried out to determine the effect of material discontinuities on rock sample mechanical properties. The investigations consisted of detecting discontinuities, observing the failure mechanisms during uniaxial compressive strength tests, and analysing of the factors affecting the strength. A non-destructive testing method has been adopted to assist in thedetection of discontinuities. Laboratory testing proved that fractures leading to failures initiated on the detected discontinuities. The location, orientation, size, density and extent of the discontinuities contribute to different modes of failure and these affect the mechanical parameters of rock samples. Four modes of failure were distinguished for hard and brittlecylindrical rock samples. These modes were referred to as simple shear failure, multiple shear failure, multiple fracturing and vertical splitting. To evaluate the effect of discontinuities on mechanical parameters, the ratio of uniaxial compressive to tensile (Brazilian) strength was calculated and analysed for the different modes of failure. It was found that the value of the ratio depended on the mode of sample failure. The lowest value of the ratio was observed for shear mode of failure and the highest for vertical splitting mode of failure.

Jan 1, 1999

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

The St George orebodies are situated within the tectonically disrupted eastern limb of the Boogardie Syncline.Highly disturbed rafts of banded chert formations occur within a sequence of felsic volcanic tuffs. The chert forms the hostrock for the gold mineralization.The gold distribution within the irregular and narrow banded chert formations is erratic and patchy. The average gold content of the two orebodies is between 3 - 4 g/t Au.Economic mining of these relative small, irregular and low grade St. George orebodies can be carried out by using a highly selective mining method.The highly selective mining method uses an excavator as the principle mining tool. Blasting, breaking and loading of the rocks is done in a different way than by using a front-end loader as with the conventional mining method. Simple, and therefore cheaper, blasting breaks the rocks and lifts them up without major displacements.

Jan 1, 1984

A series of in situ pull tests has been conducted to determine the holding capacity of the standard SS46 Split Set Stabilisers. The experiments have been conducted in a wide range of geological conditions ranging from bedded rock to blocky ground. The results presented in this paper indicate that cement grouted split sets bolts are likely to provide up to three times the initial bond strength per metre of embedment length provided by the ungrouted bolts. The increased load transfer capacity of the grouted bolts provides an alternative for permanent excavation support using split set stabilisers.

Jan 1, 1997

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

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