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By R J. Mills, B S. Sinclair, D A. Fergusson, A G. Goldstone

In 2005, Solid Energy New Zealand Limited obtained non-notified consent for the disposal of 1Mt of coal ash at the Rotowaro minesite, forming part of a coal supply agreement with the Huntly Power Station. The consenting of major mine site activities has historically required wide consultation and involves notification of the application.   The risk and cost associated with consultation can be significantly reduced via a non-notified process. A non-notified consenting process necessitates environmental effects to be shown to be æless than minorÆ, which requires the combination of robust science and a pragmatic approach to design, assessment of environmental effects, and consenting issues.   Key issues examined included consideration of how to practically operate a significant disposal project within the confines of an operating mine, minimising the costs, civil and geotechnical design and practical issues associated with traditional disposal. Environmental issues specifically related to the coal ash, led to a site specific performance driven approach to management rather than relying on conventional prescriptive approaches. Environmental issues of concern include the leaching of boron and aluminium from ash into groundwater and mine water management systems where both boron and aluminium can occur at elevated levels.   Coal ash exhibits unusual geochemical characteristics reflecting the primary coal composition and the combustion process. The dominant coal type combusted at the Huntly Power Station is derived from Rotowaro and the resulting ash is cementitious and has a high alkalinity. As a result the disposal design is based on the characteristics of the ash itself rather than the material into, or onto which the ash is disposed. Non-notified status was able to be achieved through consideration of these key characteristics of the ash, ensuring that the dimensions of the disposal site and each location was designed to minimise the flow of groundwater through the ash and demonstrating that the physical ash disposal effects are less than minor compared to the consented mining operation.

Jan 1, 2006

For years traditional optical microscopic techniques have been used successfully to carry out mineralogical studies on processing products. Essential information could be obtained by supplementing microscopic data with X-ray powder diffraction data, chemical analyses, etc. However, most of the time the mineralogists working on plant related issues, would supply qualitative information to the metallurgists, due to quantification not being possible in the available time. Since the late-80s, the use of semi-automated to automated techniques for mineral quantification has impacted positively on the use of mineralogy for optimising processing plants. Rustenburg Platinum Mines (now Anglo Platinum) were the first mining company to purchase a Qem*Sem in 1987. With the success achieved in quantifying the minerals in the concentrator streams of the Rustenburg Platinum operations, a second instrument was purchased soon after. These instruments have proven invaluable tools in understanding the flotation behaviour of the sulfide and gangue minerals in the various reefs of the Bushveld. Restrictions in the resolution of these earlier instruments, as well as the time involved in searching for and correctly identifying the fine-grained platinum-group minerals (PGM), meant that these investigations focused on the deportment of the more abundant base metal sulfides, rather than on the actual PGM. The Mineral Liberation Analyser (MLA), which became available in the late 1990s, was well suited to detect and analyse minerals occurring in trace amounts such as the PGM. Anglo Platinum was the first mining company to purchase such an instrument and now has fourteen systems operating at the AR Crown Mines site. One of the applications of these systems involves the study of feeds, concentrates and tailings from the various concentrators on a monthly basis. These routine investigations provide information on a variety of mineralogical parameters, including liberation, association, and grain size. Results are used to emphasise areas for improvement, and specifically underline those areas where improvements will have the most impact on recovery. After new or different technologies have been implemented, mineralogical characterisation of the different process streams is an essential component in the assessment of the impact of these changes on flotation performance. In addition, the knowledge is databased for future reference to draw trends across the various concentrators around the Bushveld complex, and is also used for comparative studies when plants experience high losses to tailings. Due to the success of these investigations the question was posed whether it was possible to obtain data on a daily basis, as compositing samples could hide the impact of daily events. Although the instruments currently used are suitable for a research environment, these are not ideal for mine-site implementation. For that reason Anglo Platinum, together with FEI embarked on a development program to develop a system that can be implemented on-site to measure the important mineralogical characteristics on a daily basis. Important requirements for such a system include time-to-data, ease of use and regular quality control. Highlighting some results from concentrator studies, the presentation will review the progress on the development of automated mineralogical techniques for fast, automated mineral measurements. This is an abstract only. No full paper was prepared for this abstract.

Sep 13, 2010

Spreadsheet Based Modelling of Liner Wear Impact on Charge Motion in Tumbling Mills

Sep 13, 2010

Plant based on the New Jersey refluxing process was installed at the Cockle Creek Works of Sulphide Corporation Pty. Ltd. to refine portion of the zinc output from the Imperial Smelting furnace.Refining of impure zinc is effected by distillation in two stages in vertical columns comprising a series of superimposed silicon carbide trays designed such that ascending zinc vapours and descending liquid metal are in intimate contact. In the first stage, portion of the zinc and its cadmium content are distilled from impure feed metal, condensed, and while still molten, fed to the second column in which zinc is boiled under controlled refluxing conditions to remove the cadmium content.The resultant zinc has a purity in excess of 99·995 per cent zinc.The availability of refined zinc has made possible the production of a number of zinc alloys for marketing in addition to the basic grades of zinc.

Jan 1, 1970

By C Ferron, R Massimi

There is approximately 240 000 tonnes of arsenic trioxide dust stored in underground chambers at the Giant Mine in Yellowknife, Northwest Territories, Canada. To minimise the amount of arsenic released to the environment, a number of closure alternatives are being considered. One alternative is to mine the dust, encapsulate it and dispose the mixture into a secured landfill. The potential leaching behaviour of the encapsulated dust was examined in a laboratory programme. Cylinders of arsenic trioxide dust mixed with cement/aggregate and bitumen were prepared. The dust content varied between zero per cent and 60 per cent of dry weight charge. The cement cylinders were tested for strength, leaching and freeze/thaw durability. The bitumen cylinders were tested for leaching only. The results show that increasing dust content in the cement cylinders negatively impacts the strength and the freeze/thaw durability of the samples. A contributing factor is likely the high water to cement ratio in the samples. Leaching tests show that arsenic release from cement cylinders increase with increasing dust content. Arsenic concentrations in leachates do reach a plateau at a certain point in time. Arsenic release from bitumen cylinders was significantly lower compared to cement cylinders. Arsenic concentrations eventually were less than 0.05 mg/L in samples containing up to 25 per cent arsenic trioxide dust. Arsenic leaching rates were found to decrease by an order of magnitude over the course of three months.

Jan 1, 2003

By N F. Fraser

Seafield ResourcesÆ offshore placer gold project covers c.10 000 km2 of the Westland continental shelf between Karamea and Jacksons Head, from the low-water mark out to the 120 m isobath (Figure 1). De Beers Marine (DBM), the marine diamond subsidiary of the De Beers Group, will carry out the project with geological input from Placer Solutions (PSL). DBM bring a wealth of expertise and advanced technology to the project, developed during their 20 years of exploration and mining of diamond placers on the Atlantic shelf of southern Africa, where they have also maintained a strong environmental record.   Glaciers and high-energy rivers emanating from the Southern Alps have transported substantial quantities of gold bearing sediment onto the Westland continental shelf during Pleistocene glacial periods, when fluvial gradients are steeper, sea level is c.120 m lower and most of the shelf is exposed. These deposits have been extensively reworked by the advancing shoreline and marine processes during interglacial marine transgressions, and most are now buried beneath a variable thickness of post-glacial marine sand, silt and mud. DBM will use side-scan sonar, swath bathymetry, Chirp sub-bottom profiling and a magnetometer to map the sea floor and sediments beneath it, guided by PSLÆs predictive geological model for gold distribution on the shelf. Cactus grab and vibro-core samples will be used to ground-truth the geophysics and provide stratigraphic, sedimentological and gold distribution data for incorporation into the geological model. Areas of interest identified by the geophysical and sampling data will be investigated in more detail, with closer-spaced geophysics and Mega-drill sampling to a maximum sediment depth of 20 m beneath the sea floor. These samples will be raised to the ship with air-lift suction technology, processed onboard for mineralogical and grade information, then returned to the sea floor. Environmental baseline data will be gathered from Van Veen grab samples of seabed sediment taken throughout the area during the prospecting programme.

Jan 1, 2005

Beneficiation of Coal Fines from Tailing Ponds of Tuntbilek Washing Plant

Sep 13, 2010

The pressure of low commodity prices forced the design process for the second lift of Northparkes E26 Mine to adopt a continuous improvement philosophy. The emphasis was to minimise capital expenditure while still maintaining the excellent low operating costs achieved on Lift 1. Although the first block cave lift at Northparkes is the most productive underground mine in the world and is held up as a benchmark for the use of technology in mining, areas for improvement were identified. Every area was critically assessed and investigated for the possible application of new techniques and technologies. Key learnings from the construction and production phases of Lift 1 were captured, documented and used as the starting point for the Lift 2 design. This paper shows how and why the design parameters initially used onLift 1 were changed to become the current E26 Lift 2 developmentproposal. The main differences between the two block caves arehighlighted. The alternative techniques and equipment that wereconsidered are also discussed. * Originally published in the Proceedings of MassMin 2000,published by The AusIMM.

Jan 1, 2001

By R Aseervatham

The fast tracked mine development strategy attempts to blend feasibility studies and engineering/commissioning functions into a streamlined process. In this compressed process, environmental issues are difficult to control with respect to the optimisation of operational environmental performance. This paper presents a standard mine development process with specific focus on environmental issues, and contrasts this against Rio TintoÆs recent fast track experiences on the Hail Creek project (Australia), the Baranj project (India) and the Gokwe North project (Zimbabwe).

Jan 1, 1999

This paper discusses the application of a computerised model based on genetic algorithms (GAs), called GenRel, for reliability assessment of underground mine hoisting systems. The purpose of this paper is to investigate whether GenRel can be applied to predict future failure data of a mine hoisting system based on historical records of failures. The incentive of selecting the GAs for prediction of failures is that GAs are a class of evolutionary algorithms which imitate the biological evolution procedures such as reproduction, selection, crossover and mutation. The reliability of mining equipment changes over time due to an array of factors (eg equipment age, the operating environment, number and quality of repair). These factors affect the equipment's failure patterns and have complex impacts on the equipment's reliability characteristics. The failure patterns are assumed to follow a biological evolution process, and thus GAs can be considered applicable in the modelling process.To conduct the reliability assessment, a study was carried out with historical failure data of hoists in the time period from January to December 2007. Two failure data sets of two mine hoisting systems were collected from two typical underground mines in Ontario, Canada, which are denoted as the NA mine and the SB mine. The failure data sets were prepared in the format of time between failures (TBF). Then, these data sets were entered in GenRel to generate predicted failure data sets for the period of January to March 2008. The paper discusses the statistical similarity of the actual failure data sets for the period of January to March 2008 with the predicted failure data set generated by GenRel in the same time period.

Dec 6, 2010

By H Hutchinson

Froth flotation is applied to mineral sand concentrates in order to produce commercially viable xenotime concentrates. Experiments indicate that a xenotime product containing 38% Y2O3 at 47% recovery or 34% Y2O3 at 83% recovery can be obtained from a 27% Y2O3 feed. The process involves a primary stage of reverse flotation at which oxide and silicate gangue is floated, and secondary stage of direct flotation at which xenotime is floated. Of the various collectors screened an amphoteric compound was found to be effective at both stages. This was made possible by the addition of sodium silicate at the second stage, which acted as depressant for the remainder of the gangue. Similar studies on a low grade feed material were somewhat unsatisfactory as the grade achieved fell short of what was targeted.

Jan 1, 1990

By E V. Kislov

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Northern Baikal Ni-Cu province is located in Buryatia, south-east Siberia, and geologically is part of the Baikal-Muya volcano-plutonic belt. It is known for numerous PGE-Ni-Cu-bearing mafic-ultramafic intrusions of Neoproterozoic age formed in various geodynamic settings. All these deposits can be regarded as a single Ni-Cu ore cluster located near the Kholodninskoe Pb-Zn deposit, which is ready for mining. In addition, there are less studied, small dyke-like bodies with sulfide mineralisation that formed in a rift setting and may be enriched in Ni, Cu and PGE. Individually, the known bodies are of poor commercial value by their resources, but their close spatial association (<30 km) may make these PGE-Ni-Cu deposits economic in the future. This extended abstract seeks to provide a geological framework of the North Baikal Ni-Cu-PGE province, specifically at the north-eastern Synnyr rift hosting numerous small subvolcanic bodies with Ni-Cu sulfide mineralisation. Some small subvolcanic bodies contain industrial level Ni-Cu deposits (Shanuch, Cabanga-Musongati, Voisey’s Bay, Jinchuan, etc).CITATION:Kislov, E V, 2015. North Baikal region Ni-Cu deposits , in Proceedings PACRIM 2015 Congress, pp 297–302 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Tuck M. A

The increasing depth, mechanisation and distance of working areas from surface connections places an ever greater contaminant burden on ventilation airflows. Some British Coal mines are already experiencing significant problems in providing adequate climatic conditions in the working areas and have had to introduce air conditioning. Previous work has shown that in mines of low to moderate virgin strata temperature the application of controlled district recirculation could serve to improve climatic conditions at the working area.

Jan 1, 1988

Development of Cost-Efficient Environmentally Sound Technology for Enhanced Gold Recovery from Rebellious Gold-Containing Raw Materials Study of biochemical leaching performances in gold-bearing sulfide minerals processing enabled to develop environmentally sound technology of enhanced gold recovery from rebellious gold-containing raw materials. It was found that the ?-10 IMO bacteria activity contributes to increasing system oxygen concentrations and incrementing in rates of oxygen delivery onto surface of gold-bearing minerals. Bacteria activity products, ie, amino acids (?), support the formation of such heterocomplexes as [A-Au-CN]- , providing additional gold recovery into solutions. Technological properties of proposed bacteria solutions were studied. It was found that the proposed bacteria inoculants are capable to growing directly in process of raw materials leaching within a large pH range of media containing cyanides and thiosulfates. They oxidise the sulfur to the sulfate, as well as the antimony (III) and arsenic (III) sulfides to the pentads. For the first time, the hydrophobic cell properties, metabolites emulsifying efficiency, adsorption properties, wetting ability, surface tension and electro-kinetic potential of new bacteria strain solutions were studied as compared with chemical solutions. It was found that the proposed bacteria inoculants reduce surface tension at the solvent-mineral and solvent-concentrate phase boundaries. All aforementioned effects enhance mass transfer processes efficiency. IR-spectroscopy of new bacteria strain culture liquid allowed identifying available amino acids which substantially contribute to heterocomplex anion [A-Au-CN]- formation. Active involvement of heterotrophic bacteria in gold dissolving processes was identified. It was shown that the structure of metals complexes is substantially modified at intensive pulp agitation and during long-term storage. Fractional order reaction in biochemical and chemical gold leaching was identified. It evidences that the gold and impurity metals dissolving processes advance in synchronism. The both processes are running in diffusion zone. Biochemical leaching has advantages over chemical leaching, ie it provides enhanced rates of precious metals dissolving, improved gold recovery by 20 - 30 per cent, decreased cyanide consumption by 50 per cent. At the same time it allows to decontaminate dangerous substances contained in productive solutions produced in rebellious gold-containing raw materials processing. Basic parameters of flotation concentrates leaching by heterotrophic bacteria-assisted processing technology were tried and tested. Technology of gold sorption from leaching solutions was successfully tested.

Sep 13, 2010

By Y Yamaguchi, S Nomura, M Matsumura, C Kamijo

In order to increase productivity and decrease reducing agent rate (RAR) of blast furnaces, slag content of sinter ore must be decreased. However, gangue content in iron ore tends to increase because of resource depletion. Therefore, amount of high-grade concentrate in sinter ore feeds should be increased, but this situation causes a decrease in permeability of the sintering bed so that the productivity of sinter process decreases. In order to increase the amount of concentrate, NSSMS has developed the P-type separate granulation method, RF-MEBIOS and SPEx II technologies. These technologies have been introduced to actual sintering machines. In this report, a new technology using microparticles of iron ore is proposed to increase the amount of concentrate in sinter blends. Basic experiments simulating the sinter making process using microparticles of iron ore were undertaken. Crushed pisolite, containing >60 wt per cent -10 µm was prepared for binder. The pisolite microparticle binder was mixed with another Australian sinter feed ore in a high-speed agitating mixer. They were mixed for about one minute, and then granulated using a pan pelletiser. After that, they were added to another raw material mixed by a drum mixer, and then charged in a pot for a sinter pot test. As a result, when the amount of concentrate increased from 13 wt per cent to 20 wt per cent, productivity was almost kept constant using pisolite microparticle binder.CITATION:Kamijo, C, Yamaguchi, Y, Matsumura, M, Kawaguchi, T and Nomura, S, 2017. Development of an iron ore microparticle binder for increasing the concentrate content of sinter blends, in Proceedings Iron Ore 2017, pp 69–74 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By J M. Galvin, B J. McKinnon

Lightning Ridge, Australia, is the largest opal producing area in the world. Most opal is mined from shallow underground mines by individuals or small partnerships with the industry having been protected from large-scale development to date. The safety performance of opal mining has lagged both general mining industry standards and community expectations. The application of geotechnical analysis to the opal fields has the potential to considerably reduce injuries and fatalities. With consideration of the local culture, preliminary geotechnical analysis has been applied to some current methods of work utilised at Lightning Ridge. Practical solutions have been advocated and are presented in this paper. Improvements to safety generated by these practical solutions indicate that further geotechnical research at Lightning Ridge is warranted and would be beneficial.

Jan 1, 2002

Gold, silver and palladium may be separated from the other base metals and sulphur contained in copper sulphide precipitates derived from the Sherritt-Gordon nickel process using a process involving an oxidation roast, a reduction roast and a Cu(II)/acetonitrile leach. Sulphur is removed as SO, in an oxidation roast and the hot calcine is reduced with carbon, or with carbon plus cuprous chloride. The resulting product contains metallic copper which is readily dissolved with cupric ions in aqueous acetonitrile solution. Copper powder is recovered by thermal disproportionation. The residue contains the bulk of the iron and precious metals and may be treated by a number of methods, including direct cyanidation or melting with suitable fluxes. Melting the residue will produce a copper alloy containing the precious metals and remove the iron as a slag. The alloy can be recycled to the copper leaching stage or sent for toll refining depending on the precious metal content. Impurities from the leaching circuit are controlled by a bleed circuit which in one approach utilizes the SO, from the calciner to produce Chevreul's salt and separates copper from the soluble cobalt and nickel. Alternatively, the bleed may be directed back to the main refinery copper boil stage or oxydrolysis stage.

Jan 1, 1982

By A H. Clemens, T A. Moore

This paper discusses a number of technical issues related to marketing coal. It outlines how the results of research undertaken in New Zealand and overseas can help producers address a range of technical factors that impact on production costs and marketability. The paper also discusses trends in coal utilisation for power generation and how new technologies may require coal with different characteristics. Research and development into options for CO2 sequestration are discussed including carbon storage in forests, and removal of CO2 from flue or fuel gas in power stations, and its disposal.

Jan 1, 1997

In coal mining, geophysical techniques have an established application in determining the location of seam boundaries ahead of the face so that underground mines can be planned to avoid any geological structures that might disrupt production. Geophysics can also be used in geotechnical studies to determine the in situ properties of the rock mass and the response of the rock mass to the mining. The use of geophysical logs and microseismic monitoring in these geotechnical applications are discussed in this paper.

Jan 1, 2002

The first part (lH of this work dealt with the process of recrystallization of single crystals of lead after deformation by creep, as revealed by macroscopical examination. It was shown that when recrystallization commenced, a crystal, termed the primary crystal, started to grow at the edge of the specimen and extended into the body of the specimen along the slip planes. At some stage during the growth of this crystal, other crystals appeared at the boundary of this first crystal and fragments of the parent crystal. From thispoint, recrystallization was accelerated with relatively rapid necking down of the specimen until fracture occurred.All those crystals formed after the primary crystal were given the term secondary crystals. In the present paper is given a detailed account of the orientations of the primary and secondary crystals.EXPERIMENTAL METHODThe size of the test pieces and the manner of loading were given in the previous paper (1). X-ray back reflection photographs were taken of the individual primary and secondary crystals and from them were determined the orientations. The path of the X-ray beam was perpendicular to the surface of the creep specimen.In view of the large number of photographs needed, gold...

Jan 1, 1940