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Demonstration of Solid-Liquid Separations Using Recycled Supernatant that Contains Temperature-Responsive Polymer The effective use of recycled supernatant that contains temperature-responsive flocculant is demonstrated for solid-liquid separations. The recyclability of poly(N-isopropylacrylamide) (PNIPAM) of several different molecular weights and a 15 per cent negatively charged derivative are compared. Batch settling tests of a-alumina suspensions are first conducted at 50¦C, with a subsequent 25¦C period, after which the supernatant is harvested and used to flocculate subsequent suspensions. Using this procedure consecutive separations are obtained with the repeated recycling of uncharged PNIPAM containing supernatant. Batch settling tests indicate that hindered settling rates increase with molecular weight of PNIPAM. Adsorption studies indicate that strong adsorption of PNIPAM onto alumina occurs with PNIPAM at 50¦C and that significant desorption occurs after cooling at 25¦C. However, the extent of desorption decreases with molecular weight resulting in low amounts of PNIPAM for recycling and poor settling behaviour when high molecular weight PNIPAM is recycled. Little recyclability was evident using the negatively charged PNIPAM. On the basis of these findings a recycling-thickener apparatus that uses low molecular weight uncharged PNIPAM is proposed.

Sep 13, 2010

An understanding of the origin of mineral deposits and their relationship to local and global geotectonics is essential if regional targets for mineral exploration are to be chosen. Volcanism, metamorphism and tectonism are especially significant for the origin and emplacement of mineral deposits, which, far from being fortuitous oddities of nature, occupy well defined positions within distinctive lithofacies. Thus, suggestions for mineral exploration targets can be made taking into consideration the position of 'fossil' convergent and divergent plate tectonic boundaries to indicate areas of specific types of mineralisation. To be borne in mind, though, that level of exposure, time and location of magma generation are all additional and important controlling factors. To further understand the importance of the above parameters, one must refer to the concept of paired metamorphic belts (Miyashiro 1973) which develop during an orognic cycle. These belts are generally constructed in such a way that an ophiolite type complex with metamorphic grades related to high pressure and moderate temperature regimes is flanked by an area of calc-alkaline volcanism and granitic activity with metamorphic grades within a region of high temperature and low pressure. The former situation is usually the seat of primary magmatic mineralisation, whereas the latter contains base metal. Deposits of acid plutonic and volcanic association. As will be seen later, this particular metamorphic-volcano-orogenic situation is well developed in some parts of New Zealand. For the present purpose a distribution of potential ores as related to plate tectonic processes is given below:a) Divergent plate boundaries: primary magmatic Ni-Cu, Pt,Cr, PeS2 and Cu, Pb,Zn in hot brines-hydrothermal environments Mn deposits.b) Convergent plate boundaries: stratabound Cu-Fb-Zn-Ag of felsic volcanogenic association. Porphyry eu-Au of island arc type, porphyry Cu-Mo of continental type. Cu, Au, Y, Sn, Hg, Sb of vein type and replacement lode related to granitic activity.c) Au of hydrothermal vein association, related to late dynamo-metamorphic events. By virtue of ocean floor spreading, regions of divergent plate boundaries are eventually juxtaposed or welded n to areas where plate collisions occur. This is then followed by partial melting due to various causes, just above the descending plate; thus creating a zone of acid to intermediate magmatism. The final picture is that of an orogenic zone with the paired metamorphic belts outlined above.

Jan 1, 1976

By C Tickell

Achieving occupational health and environmental noise objectives is a major consideration in the planning or operational phase of resource development and industrial projects to meet the needs of the workforce and community and comply with legislative requirements. For material handling systems, ventilation plants, mobile equipment, process plants and fixed infrastructure, noise emissions need to be considered at the design phase. The preferred approach is to provide noise emission technical specifications, but in many cases this is not stipulated. An occupational noise requirement, such as ‘not to exceed 85 dBA at 1 m’, is often provided, but this will not achieve the required occupational or environmental noise objectives and may cause overly stringent requirements when they may not be needed. It should be noted that when developing the technical specification, measuring compliance needs to be taken into account as, in some cases, measuring may be very difficult or even not possible.This paper will discuss the requirements for providing an effective noise specification that ensures the environmental and occupational noise objectives are able to be achieved and that, once installed, compliance can be measured. It discusses planning such as when to set the objective, correlating the appropriate objectives for the environmental and occupational noise requirements, allowing for measurement tolerance, providing a suitable criteria and data format for the suppliers to respond to and methodology to measure compliance. Different phases of a project require different approaches to planning for noise management and these will be discussed in the paper. Examples from 35 years of industry experience will be included.CITATION:Tickell, C, 2016. Preparing effective specifications for occupational health and environmental noise objectives in mining project design and delivery, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 781–788 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

The suitability of char from Yallourn brown coal as a filler for carbon electrodes used in the aluminium smelting industry has been assessed on the basis of the specifications usually laid down by electrode manufacturers for petroleum coke fillers. The purity specifications can be met by a simple acid leaching of the coal before carbonization. The true density of char produced at 1200°C is within 5 per cent of the specification figure, but the bulk density of char obtained from as-mined coal is only half that specified for petroleum coke.Although this can be increased to three-quarters of the specified figure by briquetting the coal before carbonization, further increases would be very difficult to achieve, as the remaining shortfall in density is due to an extensive microporosity developed in the particles of char during carbonization.

Jan 1, 1970

Process Simulation and Plant Design of a Mineral Selective Magnetising Flash Roasting Plant Using Neutrons

Sep 13, 2010

By M J. Begbie, P C. Keall, M P. Simpson

The Golden Cross low sulfidation epithermal deposit occurs in pervasively altered andesite of the Waipupu Formation and in the Waiharakeke Dacite. The unaltered, post-mineral Whakamoehau Andesite overlies these units. The Empire zone of the Golden Cross deposit contains a stockwork which is currently mined by open pit methods, and a series of veins that are mined underground. Alteration envelops both the underground and open pit mineralisation. The core of the alteration zone contains silicification, as quartz veins, and adularia. Shallow portions of the system contain illite-smectite and a thermally unstable chlorite, tentatively identified as corrensite, which pass downward into illite and chlorite, respectively. Replacement calcite occurs widely throughout the altered zone; pyrite is nearly ubiquitous. This alteration assemblage indicates formation from near-neutral alkali chloride waters. A late, post-mineralisation alteration assemblage of calcite, smectite, illitesmectite, kaolinite and siderite presumably formed from weakly acidic, steam-heated CO2-rich waters.   We have identified eight stages of vein formation: (1) sulfide veins, (2) black veins, (3) massive veins, (4) banded veins, (5) thin white veins, (6) crumbly veins, (7) massive/platy calcite veins, and (8) flattened rhomb calcite veins. Gold mineralisation occurred relatively early in the lifetime of the system, dominantly during 2 through 4. The late calcite veins (7 and 8) and early sulfide veins (1) are barren.  

Jan 1, 1997

Solid. dense, air-cooled slag can fulfil most, if not all, the functions of natural stone for civil engineering purposes. The value of pumice, also, has long been appreciated, and processes for the manufacture of similar synthetic material for light-weight concretes and insulating fills have been developed in past years.Foamed slag is, in effect, blast furnace pumice and is often referred to on the European continent as metallurgical pumice. It is made by the treatment of molten blast furnace slags with a critical quantity of water during which process the slag cools and expands into a sponge-like mass. The connection between foamed slag and air-cooled slag is also considered and a basis for density control given.All blast furnace slag cannot be foamed to give a product which would comply with B.S.S.877; 1939 Foamed Blast Furnace Slag. A large proportion of the total output of molten slag lacks the necessary inherent properties. This investigation attempts to discover the conditions necessary for the production of foamed slag capable of meeting the British specification.EARLIER WORKIt was generally accepted (Parker, 1951; Gallai-Hatchard, 1955) that the spongy structure of foamed slag was caused mechanically by steam trapped in the slag when it was poured into water. It was assumed that slags which would not foam would not trap steam, because their viscosities and surface tensions were unsatisfactory, on account of temperature and/or composition. The earliest systematic investigation was made by Frisak (1923) who attempted to establish a limiting chemical composition for foamable slags. He decided that foamable slags covered most blast furnace slag compositions on the basis of silica, alumina, and lime, and further "that the replacement of lime by magnesia up to 15 per cent has no noteworthy effect on foamability, that moderate quantities of alkalis are not deleterious, that sulphur raises the foamability and that MnO is only deleterious in the presence of 1...

Jan 1, 1963

By H Sofatzis, J Kinal, J Siliezar, B Kirkwood

Ernest Henry Mining (EHM) is a copper, gold and magnetite mining and processing operation located 38 kilometres north east of Cloncurry in the Mount Isa - Cloncurry mineral district of north west Queensland, Australia. The EHM ore body is an iron oxide copper gold deposit with an average grade of 1.1 percent copper, 0.5 g/tonne gold and 22 percent magnetite.At the end of 2009, after a series of promising laboratory test work, EHM converted the ball mill media charge from forged steel to high chrome media. Laboratory test work also indicated that with the use of high chrome media, the pH was able to be reduced with no negative impact on plant performance. At high pH values (above 10.5), the forged media is passivated, so as the pH of the system drops the media corrosion rate increases and floods the system with corrosion products, affecting flotation. As the high chrome media is much more inert, pH has less of an effect on copper flotation response.This paper provides an overview of the effects of reducing the pH in the EHM copper rougher flotation circuit. The pH in the roughers was dropped from 10.6 to 9.6 to determine the impact on the rougher performance and the subsequent performance of the whole copper flotation circuit. It was found that there was a slightly increased improvement in copper recovery and no statistical change in either the rougher or final copper concentrate grades for copper and gold.With the reduction in pH, there was a noticeable reduction in lime usage from 0.85 kg of lime per tonne of ore processed to 0.55 kg/t. This reduction in lime is equivalent to approximately $700,000 per annum at current production rates.CITATION:Kirkwood, B, Kinal, J, Siliezar, J and Sofatzis, H, 2013. Low pH trial in the Ernest Henry Mining copper rougher flotation circuit, in Proceedings MetPlant 2013 , pp 371-377 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

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 W D. Rech, K W. Keskimaki

As an integral part of the conversion from rail haulage to conveyor haulage at Henderson, over six kilometres of drifting and several large complex openings were mined. The deepest of these areas was nearly two kilometres beneath the surface, bringing all of the challenges of rock stress and heat that come with mining at these depths. Though many mines operate at these depths, the development of the infrastructure necessary to support a 36 000 tonne per day caving operation brought some unique challenges to the development mining activity. The issues handled include: finding experienced staff for a æfast trackÆ development program; rock bursts and ground conditions; inflow of 50 degree centigrade water; acceleration of the project completion; large diameter raise boring and difficult muck handling.

Jan 1, 2000

The Waimumu area, 12 km southwest of Gore, is underlain by the Gore Lignite Measures, an early Tertiary fluvial sequence approximately 500 m thick resting on Triassic-Jurassic argillitic basement. The Waimumu Quartz Gravels (Pliocene) have been deposited locally and are in part due to the localised reworking of the Gore Lignite Measures. Structurally the area is dominated by the Dunsdale Fault System, a steeply dipping series of NE trending reverse faults (Isaac and Lindqvist, 1990). The Belle-Brook, Hedgehope and Parker Road sites sampled are adjacent to the downthrown (east) side of the Hedgehope Fault.The authigenic gold-sulphide association at Belle-Brook was discovered in 1987 (Falconer, 1987: Clough and Craw, 1989). Despite a very limited amount of alluvial mining a significant quantity of authigenic marcasite has developed. Authigenic sulphide trace element analysis has shown anomalous amounts of As, Ni, Cr and to a lesser extent Zn, Pb and eu (Table 1). It has been established that the nickel occurs as a colloform banded Ni sulphide, possibly bravoite, within the marcasite (Figures 1 & 2). Arsenic and nickel (re)mobilisation are well documented in the literature. Generally As and heavy metals are mobilised in the groundwater as a result of the oxidation of sulphides (ie as a result of mining). At Belle-Brook it is reasonable to assume the authigenic sulphide trace element composition reflects either localised groundwater contamination or hydrothermal mineralisation. This poster presents some preliminary findings.

Jan 1, 2001

The Oregon-Idaho graben evolved after widespread tholeiitic flood basalt volcanism associated with the arrival of the plume head of the Yellowstone hotspot beneath southeastern Oregon approximately 17 - 16 Ma. The north- to north-northeast-trending, 50 km-wide graben evolved between 15.5 and 10.5 Ma during east-west extension. The graben is part of a middle Miocene back-arc rift (1100 km long) that includes the northern Nevada rift, the Baker and LaGrande grabens, and the Chief Joseph dike swarm of the Columbia River Basalt Group. The graben ceased to be a volcanotectonic depression as the cross-cutting western Snake River plain began to evolve at approximately 10.5 Ma. At about 14.3 Ma and continuing to approximately 12.6 Ma the Oregon-Idaho graben began to break up into subbasins that were bounded by intragraben fault zones. The break up was accompanied by a change to calc-alkaline volcanism that persisted within the Oregon-Idaho graben until 8.1 Ma, approximately 2.5 million years after subsidence within the graben ceased. Three intragraben fault zones have been identified and a fourth is inferred. The easternmost, the Devils Gate fault zone, coincides with the magmatic axis of the graben at approximately 14.3 Ma. By approximately 13.5 Ma the magmatic axis had shifted to the west along the Dry Creek Buttes and Wall Rock Ridge fault zones. A diffuse magmatic axis developed at approximately 12 Ma farther to the west where the fourth intragraben fault zone is inferred. In addition to serving as conduits for the ascent of basalt, basaltic andesite, rhyodacite, and rhyolite magmas, the zones focused the discharge of large geothermal systems. The intragraben fault zones display a common evolutionary pattern. The 2 to 3 km-wide zones initially control the distribution of facies in volcaniclastic sediments and the location of basalt hydrovolcanic vents. During this stage, the fault zones may have had no surface expression other than a low elevation change on a relatively low-relief landscape. As relief developed by continued deformation along the fault zones, strike-length of individual faults increased and weakly consolidated volcaniclastic sediments, silicified sediments and hot-spring sinter, and palagonite were eroded from the uplifted blocks and deposited in neighboring subbasins. It is during this stage that the large hot-spring precious-metals bearing prospects evolved. Displacements of over 150 m on a few faults within the zones and possible reversal of the sense of displacement along the zones occurred in this final stage of development. Locally, the fault zones were remobilised during the subsidence of the cross-cutting western Snake River plain. The intragraben fault zones within the Oregon-Idaho graben illustrate the relations among syntectonic volcanism and sedimentation and the evolution of geothermal systems within continental rift systems.

Jan 1, 1995

By M Salu

Ventilation control devices (VCD’s) and bulkheads are critical controls used for managing risk in underground coalmines. Following the Moura No. 2 mine explosion in 1994, the Queensland Mines Department required that the design of VCDs be based on live testing (such as in a mine testing explosion gallery) and more recently on numerical modelling using measured seal material properties. While the stipulated methods represent an idealistic solution, they are not practical to implement as solutions to daily challenges presented in underground coalmines.Not all VCD’s and bulkheads are placed in areas which have been mined to standard roadway dimensions. Operationally, VCD’s may be required to be placed close to intersections or require large dimensionally different areas (eg overcasts and pre-driven recovery road shutters) compared to the live testing or numerical modelling originally undertaken.This paper describes the various structural engineering methods utilised to account for the design of VCD’s where the operational requirements are non-standard. Siting and construction of VCD’s near the entry of cut throughs and geological structures requires additional design considerations. While VCDs constructed from a single material (eg sprayed mining plaster) are relatively straightforward to design, the addition of multiple openings (doors) or large pipes will complicate the structuralanalysis significantly.Temporary bulkheads used for the containment of grout such as for the construction of pre-driven recovery roads in coal mining have a significantly different risk profile to VCDs and should be designed accordingly. Recent failures and near-misses in such bulkheads have highlighted this issuefor the authors.The existence of an Australian Standard for Underground Mine VCDs and Bulkheads would go a long way to addressing many of the issues raised in this paper. Without a single, industry-accepted reference for VCD design, individual mines will have to continueto exercise their best judgements using whatever local expertise is available to them.

Oct 12, 2022

During the first five years of operation, the Lihir gold mine has steadily increased plant throughput rate to over 4 Mtpa, well above the original design capacity of 2.8 Mtpa. Understanding how future variations in ore type impact on plant performance has been an integral part of LihirÆs development program. This paper discusses the key drivers for significant improvements to the plant, including a second oxygen plant, a pilot flotation plant, an autoclave heat recovery circuit, a pebble crushing circuit and additional autoclave feed pumping capacity. The result is a process plant with the flexibility to accommodate variations in ore type without significant loss of throughput.

Jan 1, 2003

ON mineral lease 38 of the Sulphide Corporation Limited, Broken Hill, a shaft was sunk in the early days Ior prospecting purposes and at the present time it is accessible as far as the 1000-ft. level where a connexion exists with the main workings of the Corporation's Central Mine, mineral lease 9. About the year 1895· a crosscut was driven east from this shaft at the 1330-ft. level cutting the Central Ore-body in mineral lease 9 and the shaft is supposed to extend a further depth of 25 ft; but no records of any of this work are in existence, the whole of the evidence being based on hearsay and memory:Fig. 1 shows the position of the Extended shaft in relation to the main workings. The shaft filled with water to the 1000-ft. level where it overflowed through the crosscut to the main shaft and was pumped to the surface, but when the South drive on the 1300-ft. level was pushed to the southern boundary, it was deemed advisable for safety, to tap the water at this level and so relieve the...

Jan 1, 1919

By L Stitz, S Kinnear, L D. Fabbro

Sensitive and tolerant species of macroinvertebrates were present across a wide range of conductivity concentrations in the Isaac River catchment in Central Queensland, indicating the need for further ecological studies in the field to underpin the development of regionally-tailored guidelines for conductivity. The Isaac catchment has naturally high conductivity, but there is also increasing pressure on resource companies to ameliorate saline mine water discharge. Recently, catchment management efforts have included a revision of the water quality guidelines that are specific for the broader Fitzroy catchment. These guidelines include the use of macroinvertebrates as indicators of ecosystem health, but developing and applying such guidelines first requires a good understanding of macroinvertebrate ecology and population dynamics, ideally from field validation. To date, studies of macroinvertebrate tolerance to conductivity in southern freshwaters, as well as in laboratory-based ecotoxicological tests conducted in Queensland, have suggested that ranges exceeding 1000 ¦S/cm are likely to have negative impacts on survivorship of all taxa. However, these results may not be transferable to natural populations of macroinvertebrates from the Isaac, where the naturally high-conductivity water may allow the opportunity for adaptation. To test this, macroinvertebrate assemblages were examined at a series of sites in the upper Isaac River catchment at the end of the dry season in 2012. Patterns in the assemblages were examined together with water quality parameters, in order to gauge the ability of macroinvertebrates to survive at conductivity concentrations exceeding 1000 ¦S/cm. The specific conductance of the field sites ranged from 477 ¦S/cm to 9791 ¦S/cm and a total of 39 families from 13 orders were identified. Species richness was not significantly different between sites of differing conductivity. Macroinvertebrate populations were dominated by Dipterans as well as the traditionally more pollution-sensitive families Ephemeroptera and Trichoptera. There was an absence of any correlation between conductivity and species richness (P > 0.050), suggesting that macroinvertebrate taxa richness occurs independently of conductivity, at least in this particular cohort of mining and/or grazing influenced ephemeral systems in Central Queensland.CITATION:Stitz, L, Fabbro, L D and Kinnear, S, 2013. Macroinvertebrate tolerance across a range of conductivities in the Isaac River Catchment (Central Queensland), in Proceedings Water in Mining 2013 , pp 135-142 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By Baker G

The exposures resulting from development work, following on the discovery of a new shoot of hIgh grade ore at the north end of the Sardine tin mine, during 1952, have provided an unusual opportunity to study the oxidation of a stannite-rich ore. Through the kindness of C. C. Morton, Chief Government Geologist of Queensland, an exactly located suite of specimens representative of the exposures was supplied by J. and W. Reddie. This was later supplemented by a number of specimens culled from a parcel ofrepresentative ore submitted to the Melbourne Ore Dressing Laboratory for testing.The Sardine tin mine, near Ewan, Queensland, has been the outstanding producer of the Kangaroo Hills Mineral Field. Since its discovery in 1918, up to 1952 it has yielded about 1,500 tons of cassiterite concentrates, and about 85 tons of stannite concentrates. The outcrop ore averaged 35% tin oxide, but the grade declined with increasing depth, and by 1930 had fallen to 7% tin oxide. In the northern section of the mine the ore shoots show a downward passage to complex primary s.ulphide ore, containing cassiterite and abundant stannite.The orebodies occur in a series of fissures in a crushed zone about 50 ft. wide in slates and quartzites that have been intruded by granite (Connah, 1952). A quartz porphyry dyke forms the footwall of the original main lode in its southern part, being traced' from the surface to' the No. 4 level (173 ft. vertical depth), and two narrow dolerite dykes were encountered in the workings north of the main...

Jan 1, 1954

By R Milton, D Hake, H Sprague

The North Western Sewer tunnel extends over 11.5 km in the North Western suburbs of Melbourne.The $253 million tunnel project provides a critical link in the Melbourne Sewer Network. The existing sewers fail to service the increasing demands of the growing population of the North West regions of Melbourne. This project will protect the environment and improve the standards of service of the existing system. This paper concentrates on Section three of this project, consisting of the final 4 km of the Contract, three access shafts and a cut and cover section of tunnel.Transfield Tunnelling as Head Contractor constructed the tunnel for Melbourne Water Corporation, with Enetech Streamline, formally Streamline Australia, a trading arm of Melbourne Water acting as Superintendent.Excavation of Section three of this project commenced in September 1994 and project completion is scheduled for October 1998. The tunnel passes below the residential suburb of Essendon, through some of the most challenging ground conditions ever attempted to be tunnelled in Australia.

Jan 1, 1999

The Precambrian Eastern Creek Volcanics comprises spilitic basalts with interbedded sediments and tuffs which were extruded and deposited during Middle Proterozoic time. The rocks have undergone low-grade regional metamorphism.The Eastern Creek Volcanics are approximately 17,000 ft thick and have been divided into four units.The rocks were laid down in a geosynclinal basin elongate to the north. The main structural features are the northerly trending Mount Isa and Gorge Creek-Quilalar fault systems.Major east-west faults cause repetition of the sequence.Copper and uranium mineralization is known within the formation. Copper mineralization is confined to quartz-filled shears anp basalts. Nothing of economic importance has been found in the area though ore deposits have been found elsewhere in this type of environment.

Jan 1, 1968

Great new drilling results! What's so sinful about being a multi-national company? Overseas protestors flown to Australia for a free holiday How to counter the protectionist danger? Our current economic standing Over-regulation puts a convicted paedophile on the payroll The broken window fallacy Mining - A shared history Aristotle and the camels A brighter future? Something over which we do have far greater control, i.e. leadership within our own industry My challenge to you The expanding gold- producing company of which I am proud to be Chairman, Croesus Mining NL, is by definition a æmultinationalÆ. Our shareholders are based in 36 different countries, 77% of our 107 million shares are held in Australia, 23% are held outside Australia, and include New Zealand holdings of 7%. In September, Croesus Mining presented our company at the Mining 2000 Forum in Melbourne, a city caught up with multinational protestors demonstrating against multi-national companies.  

Jan 1, 2000