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By Patterson J. H

An infra-red absorption study has been made of crocidolite, country rock. and associated host rocks from Wittenoom Gorge. The spectrum of the country rock is appreciably different from those of crocidolite and the magnetite-rich host rocks which are closely similar. A process to separate crocidolite-bearing ore from country rock based on infra-red emission is therefore possible in theory.

Jan 1, 1966

By J Parr, P Ashworth, S Johns, C Yeats, A Littleboy

The ocean floor is increasingly being discussed in terms of its resource potential. New discoveries, improved knowledge and access to unexplored areas of the deep sea and continental shelf are some factors contributing to a renewed interest in the seafloor exploration and mining industry. The industry has been referred to as the ænext minerals frontierÆ. To date, much of the research has focused on proving economic and technical viability of the industry, with environmental issues addressed locally. However, there is limited research internationally, and none known in Australia that considers the social viability of the industry, addressing issues such as regulatory contexts, international precedence and public acceptability. Does the nascent seafloor exploration and mining industry have a social license to operate? Does it have support amongst the wider community? If not, why not? The Wealth from Oceans National Research Flagship explored these questions by scoping the social issues that would surround an expansion. Two desktop studies provide insight into the current level of activity in seafloor exploration and mining, recent developments and the regulatory regimes on which the industry is based. One study focused on the situation in Australia, while the other was internationally focused. A series of workshops were held with key stakeholders from government agencies, industry and other interested parties, such as environmental groups and the fisheries industry. These workshops identified and explored the different stakeholdersÆ perceptions of the benefits, concerns, opportunities and key questions associated with an expansion of the seafloor mining industry. The desktop studies revealed that Australia is one of only a few countries with legislation specific to seafloor exploration and mining. Nevertheless, barriers to licence approval exist because of lack of precedent in applying this legislation. Consequently, the decision process can be vulnerable to political issues and subjective judgements. The outcomes from the stakeholder workshops suggest this inconsistency may be influenced by the high levels of concern and uncertainty over environmental impacts. Uncertainty over environmental impacts can influence the acceptability of an environmental impact assessment (EIA) and also mean the perception of risk is variable. Overall, this research suggests that the future of the seafloor exploration and mining industry will be highly dependent on AustraliaÆs ability to:improve the knowledge-base underpinning the regulatory regime,generate open and transparent communications between stakeholders, andimprove the understanding of policy and regulatory processes.

Jan 1, 2008

Retreating Cu-Mo Rougher Tailing by Flotation for Concentration of Copper and Molybdenum

Sep 13, 2010

By Belcher C. B

A procedure was required for the rapid determination of silicon in low-alloy irons and a suitable method used the formation and reduction of silicomolybdic acid at 50°C. The procedure gives results for elemental silicon and this enables the correct computation of oxidation requirements in basic oxygen steelmaking. The method could be useful in iron foundries which have not installed direct reading spectrometers.INTRODUCTIONOxygen steelmaking experiments required rapid determinations of 0,5-1,6 per cent silicon in iron (3-4 per cent C) within 10 min of sampling; a reproducibility better than ±0.03 per cent Si was desired. Only elemental silicon (Si°) is of interest as a fuel in basic oxygen steelmaking technology, and the proposed procedure determines exclusively this form of silicon. The method is described as it may prove useful to other workers although the interference study would be incomplete for some applications.The analysis of silicon in iron is frequently obtained using direct reading spectrometers, but for the proposed experiments the spectrometers could not be used because of the prohibitive distance from the furnace. It should be noted that spectrometers determine both the elemental silicon and that present as silicon dioxide in occluded slag and inclusions.The silicon content of iron and steel is determined in this laboratory by spectrophotometric measurement of a "molybdenum blue" colour. The reactions involved have been extensively investigated; Strickland (1952) showed that a...

Jan 1, 1965

On the Hauraki goldfields, within the limits of Cape Colville Peninsula, the Paheozoic rocks are confined to the district north of a line drawn from Mercury Bay on the east coast to Rocky Point on the shore of the Frith of Thames. South of Kennedy's Bay they are developed on the east coast only at Kuaotunu, at which place gold mining is carried on in sandstones and slates of this age. Between Tapu Creek and Coromandel there is, along and adjacent to the shore of the gulf, a very considerable development of PaJreozoic and in part of Trias rocks, and between the Tiki Stream and the northern end of Tokatea Hill, along the western slope of the main range, lies the special area of the Palreozoic or carboniferous rocks that have more particularly to be dealt with in this paper. The same formation has a large devolpment between Cabbage Bay and the northern slopes of Moehau, and appears to the water marge on both sides of this part of the peninsula.In this part they are of special interest as having, on the west spur of Moehau, a considerable variety of dyke rocks intruded into the sedimentaries, the interest in which is increased by the fact that these dykes theIllselves are of Palreozoic age and correspond to the dykes that are so' abundant in the Tokatea-Tiki area. It is this Tokatea-Tiki area as a goldfield, and its rocks as distinguished from later volcanic' products' on other parts 'of the peninsula...

Jan 1, 1903

In eastern China, most of the copper skarn deposits occur in folded troughs which are controlled by the EW-trending faulted fold systems (the Pal-Asian geotectonic domain), and the NNE-trending rift or fault zones (the Marginal-Pacific geotectonic domain), particularly the later. From the north to the south, there are four troughs hosting the main copper skarn deposits in eastern China: the Yanliao Trough, the Yangzi River Trough, The Qiantang-Yuanshui Trough and the Zichen Trough. There are more than 30 copper skarn deposits in eastern China, and ore reserves of each deposit are between 30 to 100 Mt with average grades over 1% Cu.    Most of the large copper skarn deposit-related intrusions are Mesozoic in age (170 to 100 Ma) and were emplaced during the Yanshanian Movement. Outwards from the intrusion bodies, both the skarn alteration and mineralisation show certain patterns of zonation. Mineral assemblages indicate a relatively high oxidisation state during metasomatic alteration and mineralisation. Sulphur isotopic work indicates that most d34S values of the sulphides are between ~4 to 3ë suggesting a common magmatic sulphur source. Fluid inclusion and oxygen isotopic studies suggest that early-stage fluid shows magma-related fluid characteristics although meteoric water was involved during late-stage alteration.

Jan 1, 1995

By J Bresnahan, D Kepert, R Murray, R Neroni

Stratigraphy of the Hamersley Province in Western Australia, featuring alternating units of banded iron formations and shales with contrasting electrical properties in a mostly gently undulating shallow-dipping layered geometry, is particularly favourable to airborne time-domain electromagnetic mapping techniques. Manipulated vertical cross-sections of modelled conductivity obtained from laterally constrained one-dimensional inversion of SkyTEM304 data enable the exploration geologist to interpret weathering profiles, shallow-dipping stratigraphy and steep structures, all of which are crucial aspects of bedded iron ore deposits genesis models.The Cobra Project is located 14 km east of the NNW-trending Menindee Fault Zone, which defines the western margin of the Hamersley Province, Western Australia. The region comprises an extensive plateau of Brockman Iron Formation cut by a series of horst and grabens with a regional dextral strike-slip component. The 150° striking horst and grabens and associated 060° striking conjugate faults have approximate frequencies of 400 and 2000 m, respectively, and control the bulk of the iron mineralisation. Syn to late 150° trending dykes in part intrude the faults.In the Cobra region, elucidating the structurally dislocated stratigraphy without closely spaced drilling is very challenging. Geological mapping is hindered by the paucity of mappable stratigraphic markers within the banded iron formations and kinematic indicators. Airborne magnetic and remote sensing data sets highlight the dense lineament network, but provide limited assistance in quantifying relatively small apparent displacements, or distinguishing faults from dykes with reasonable confidence.Interpretation of modelled conductivity cross-sections generated from laterally constrained one-dimensional inversion of airborne electromagnetic method (AEM) data offers invaluable insight where the quality of mapping or drilling is wanting. Subsequent targeted field checking and infill drilling validated the geological model interpreted from the integration of these data sets.The AEM technique alone cannot decipher the complex geological environments often present in the Hamersley Province but can facilitate effective iron ore exploration by focusing precious field time and assisting structural and stratigraphic interpretations in areas with sporadic and shallow geological data.CITATION:Murray, R, Neroni, R, Kepert, D and Bresnahan, J, 2017. Using airborne electromagnetics to solve a structurally complex geological puzzle in the Hamersley Province, Western Australia, in Proceedings Iron Ore 2017, pp 269–276 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By D A-F Batchelor

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.South-East Asia represents the world’s most productive tin province, mainly from placers. Kalimantan has been a major diamond producer, while in the 1980s a placer gold rush occurred in Indonesia and Malaysia. Reviewing extensive geological and mining data highlights phenomenal palaeo-environmental changes in the Sundaland region, interpreted to be responsible for generating ‘giant’ placers. Correlation of the Late Cainozoic stratigraphy has been facilitated from mine exposures and drill holes distributed throughout Peninsular Malaysia, the Indonesian Tin islands and Kalimantan, including contiguous marine areas with extensive shallow seismic profiling data. Knowing the association of rich placers with palaeo-environmental episodes and stratigraphical units has been helpful to facilitate their discovery. All three placer commodities responded similarly to region-wide landscape evolution following Mio-Pliocene high sea levels. Commencing with major regression, important stages comprised: a long period of landscape stability with deep weathering during the maximum Sundaland extent gradually rising sea levels/precipitation initiated slumping of mineralised regolith to form fans, later reworked by braided streams with aggradation (Old Alluvium); during episodic pluvial periods downcutting upgraded placers significant change occurred around Middle Pleistocene time with peneplanation and pedogenesis from Late Pleistocene time ‘modern’ fluviatile deposition (Young Alluvium) filled incised V-shaped valleys.Placer seams show systematic variation in stratigraphic position, in particular cassiterite especially occurs in the Old Alluvium (equivalent Upper Dahor Formation in Kalimantan). Gold is commonly richer in gravelly younger deposits, partly because of secondary precipitation within permeable alluvium. Reworked diamonds are predominantly concentrated especially in younger fluviatile alluvium.CITATION:Batchelor, D A-F, 2015. Conceptual exploration for tin, gold and diamond placer deposits in ‘Sundaland’ (Indonesia and Malaysia) by understanding the late Cainozoic stratigraphic context, in Proceedings PACRIM 2015 Congress, pp 499–506 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Throughout history, many of the world's achievements, conflicts and problems can be traced to the demand for minerals. With the rapid expansion of our industrialised society in recent years the demand for minerals has grown to such an extent that uncertainties about availability and cost have arisen, especially in the case of energy minerals.Minerals have acquired a new dimension for governments as the availability of these resources is interwoven with the ability of governments to achieve their developmental goals on national and international levels. Accordingly, the supply of minerals will increasingly be affected by social and political factors.

Jan 1, 1986

Column Bioleaching of a Low-Grade Nickel-Bearing Sulfide Ore Yellow Mountain Deposit belonging to GobiMin Inc is located in the Chinese Tianshan and Altay orogenic belts, Hami, Xinjiang Province, NW China. Indicated Mineral Resources of its reserve are estimated at 12 million tonnes averaging 0.40 per cent nickel. Mineralogical examination and chemical analysis indicated that the Yellow Mountain ore is a type of high Fe, low Mg and low Ni sulfide ore: the main sulfide minerals are ~8.0 per cent pyrrhotite (Fe1-xS), ~1.0 per cent pentlandite ((Fe, Ni)9S8), ~0.6 per cent chalcopyrite (CuFeS2), ~0.5 per cent pyrite (FeS2), and ~0.2 per cent violarite((Fe, Ni)3S4); the main gangue minerals are ~48 per cent olivine, ~28 per cent antigorite, ~3 per cent chlorite, ~2 per cent talc, ~2 per cent tremolite, and~1.5 per cent magnetite; the chemical analysis of the ore sample are Ni 0.40 per cent, Co 0.016 per cent, Cu 0.24 per cent, Fe 12.4 per cent, S 5.6 per cent, MgO 9.6 per cent, CaO 1.80 per cent, SiO2 48.5 per cent and Al2O3 10.3 per cent. Preliminary results of the shake flask test showed that pyrrhotite is easily leached and the high concentration of ferric iron would hamper the growth of bacteria which will bring a negative impact on the bioleaching conversely. This work aims to set up a method to prevent the negative impact of the ferric ion on the bioleaching of the ore. Two method were combined to prevent the negative impact of the ferric ion, they are adaptation of the mixed bacteria to iron ion and bleeding the off-solution periodically to control the levels of iron ion (depending on the tolerance of the microorganisms to the ferric ion) in the leaching solution. Using a mixed mesophiles composed of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans under room temperature, a nickel recovery of 93 per cent and a cobalt recovery of 85 per cent were achieved in 280 days column bioleaching process with an average nickel concentration in the leaching solution of 2.6 g/L. The results showed that the negative effect of the ferric ion can be successfully controlled and the nickel can be bioleached successfully from theYellow Mountain ore.

Sep 13, 2010

The mineralogy of the rocks now observed in the Nairne pyrite deposit developed under conditions of internally-controlled sulphur activity during amphibolite facies metamorphism. In the sulphide-deficient metasediments the activity of sulphur was low, and pyrrhotite developed with iron-bearing silicate minerals. At higher sulphur activity, in the sulphide-rich meta-sediments, pyrite formed in addition to pyrrhotite, and the associated silicate minerals are iron-deficient.

Jan 1, 1969

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

Jan 1, 1990

By C J. N Wilson

The central Taupo Volcanic Zone is a region of intense Quaternary silicic volcanism accompanying rapid crustal extension. Modem central TVZ is the most frequently active and productive silicic volcanic system on Earth, erupting rhyolite at c.0.28 m3 s-1. The rhyolites show no major compositional changes with time, but the total extent of magma chamber zonation has changed with the advent of rifting and crustal extension at c.0.7 Ma. At least 34 caldera-forming ignimbrite eruptions have formed a complex sequence of relatively short-lived, nested and/or overlapping volcanic centres in central TVZ. Taupo contrasts with other large silicic magmatic systems in the exceptionally high frequency, but small size, of caldera forming eruptions. This contrast reflects the thin, rifted nature of the TVZ crust that precludes the development of long term magmatic cycles at Taupo. Within central TVZ, non-rhyolitic compositions have been erupted apparently irregularly in time and space; in particular there is no evidence for a geographic separation of basalts from andesites. TVZ is a rifted arc, but its segmented nature, high thermal flux and voluminous rhyolitic volcanism make it unique on Earth.

Jan 1, 1995

THOUGH the literature on the chamber process is considerable, it mostly refers to European conditions. Owing to the demand for acid for flotation and leaching at the mine, it may be necessary to work the process under other conditions. Consequently, some results obtained during the chlorination days at Mount Morgan, within the Tropic of Capricorn, may be useful for reference when working in a similar climate. Though the chambers must be protected against tropical storms, thorough ventilation should be provided, with plenty of space between the chambers, which are almost invariably crowded together. Not only does the space assist in the cooling of the chambers, but it is very desirable during repairs, when lead andtimber have to be hoisted up. The connecting flues between the chambers, which are fairly efficient mixers and condensers, should be round, supported from above, and with the least possible timber about them. Their position and arrangement deserve careful attention. Lattice work will be sufficient protection for the sides of the chambers, and the roof should be high and well ventilated. The Mount Morgan plant, crowded and not well situated, consisted of seven chambers (four over 50 ft. in length), one Glover tower 7 ft. 2 in sq. x 20 ft. high, one Gay Lussac 9 ft. sq. x 30 ft. higb, also one 5 ft. diam. x 25 ft. high. There was one pipe column 4: ft. sq. x 14 ft. 6 in. high. The chambers were run as one unit, and were much lower than those usually constructed in Europe-less than 15 ft. high. Provided that suitable timber can be obtained, 20 ft. is quite low enough. It should be quite satisfactory to use round poles for the studs, and so admit more air space between studs andlead.

Jan 1, 1920

Applicaton of Agricultural Residues from Pyrolysis in Flotation of Black Coal

Sep 13, 2010

By P To, A Sharp-Paul, S Jones, C Monahan

A key environmental management issue associated with mining projects is tailing disposal. In high rainfall environments this is particularly challenging and generally requires the discharge of excess water from a tailing dam to adjacent streams or coastal waters. Such discharges can potentially have adverse impacts on downstream water quality and the environmental values associated with these waters, such as providing a drinking water supply for local villagers, maintaining a fisheries resource or protecting a fish species of high conservation significance. An alternative to the construction and operation of a conventional tailing dam is Deep Sea Tailing Placement (DSTP). The key features of such a system are:Discharge of the tailing slurry at considerable depth (approximately 120 - 150 m) below the oceanÆs surface. This requires a pipeline to be laid from the process plant to a mix tank, where the tailing is mixed with seawater and entrained air released. The pipeline then continues down the ocean floor to the required discharge depth, which is below the surface mixed layer and the euphotic zone. After discharge, formation of a density current which continues to descend along the ocean floor as long as the slope is sufficiently steep. Final deposition of the tailing in an area where the slope of the ocean floor is insufficient to maintain the density current. This typically occurs at depths of more than 800 m. Water quality issues associated with DSTP include: Impacts on the oceanic water column due to the formation of subsurface plumes which break away from the descending density current. The occurrence of elevated concentrations of contaminants in the interstitial waters of the deposited tailing solids. Fluxes of contaminants from the tailing deposits into the overlying oceanic water column. This paper discusses the water quality aspects of DSTP with particular reference to a case study in Papua New Guinea. The evaluations undertaken as part of the DSTP impact assessment included consideration of both the short- and long-term chemical behaviour of contaminants and bioassays, within the appropriate water quality assessment framework.

Jan 1, 1999

Wet mining of auriferous gravels at L & MÆs Waikaka operation in Southland creates spoil dumps derived from stripping of a clay rich overburden, tailings from past dredging and the processing of auriferous sands and gravels. Over recent times, spoil dumps have slumped on six occasions, threatening the viability of the wet mining operation. Close examination of slump morphology, coupled with the sequence of material placement and rate of dumping suggested a mechanism associated with undrained failure of a 2 m layer of silt and sand tails forming the base of dumps.Commencing with some information on the geotechnical properties of source overburden, back analysis of failure morphology and sequence and development of undrained loading conditions from first principals, the most likely failure mechanism and factors controlling failure were defined. Based on analysis results, a scheme to stabilise the lowwall dumps was developed and implemented, augmented by continuous monitoring of pore pressures in the basal wet tails, and laboratory testing for confirmation of computed material properties.Lowwall spoil stability has improved since implementation involving changes to the method of spoil loading, and modification of wet tails composition to improve permeability and drainage of the basal wet tails under load. The method and approach to prediction and verification of failure mechanism provide a sound basis for continued mining of deeper auriferous gravels.

Jan 1, 2002

Plant-Based Trials of Monitoring of Coal Flotation Systems Using Electrical Impedance Spectrum Technique

Sep 13, 2010

By R J. Merchant

The Hauraki goldfield is located east of Auckland in the North Island of New Zealand. It includes Great Barrier Island, the Coromandel Peninsula and the Coromandel and Kaimai Ranges as far south as the town of Te Aroha and south east to Te Puke. It has a total north-south extent of about 180 km and an area of 3000 km2. The goldfield is the most productive in New Zealand, and while production at present is negligible, the area has undergone continuous exploration over the last seven years.

Jan 1, 1984

By R G. Barker, A B. Christie

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. More than 11 Moz of Au and 50 Moz of Ag have been produced from epithermal deposits in New Zealand, almost entirely from 50 deposits in the Hauraki goldfield. Since the 1980s, new deposits have been discovered at Waihi (Favona, Trio, Correnso) and nearby at Golden Cross. Feasibility studies into reopening the Talisman mine at Karangahake are continuing, and advanced projects with preliminary inferred resource estimates are reported at Wharekirauponga, Neavesville and Muirs. In the Taupo Volcanic Zone, 11 prospects have been drilled, resulting in the definition of large but low-grade Au-Ag resources at Ohakuri. In Northland, several Au, Ag and/or Hg prospects are known, and small quantities of Ag and Hg have been mined. Six prospects have had some drilling, with the most advanced exploration at Puhipuhi. The application of Taupo Volcanic Zone geothermal systems research to the modelling of former hydrothermal mineralising processes in some epithermal prospects has enabled better targeting of exploration.CITATION:Christie, A B and Barker, R G, 2015. Exploration for epithermal gold deposits in New Zealand, in Proceedings PACRIM 2015 Congress, pp 533–540 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015