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FOR some years past it has been usual to specify high-grade copper for use for many purposes, but the practice of specifying zinc of a high degree of purity for certain purposes is of comparatively recent origin. It is a practice, however, which is extending ag the effect of the impurities in zinc on products manufactured therefrom becomes widely recognized.The notes hereunder are intended to briefly survey the principal uses to which high-gr.ade zinc is being put, and, wherever possible, to indicate the effect of the impurities normally present in the lower grades of zinc.In the United States zinc is graded into five divisions, known respectively as "High-grade" "Intermediate" "Brass Special" "Selected," and "Prime Western." The maximum amounts of impurities allowed in the various grades are indicated in Table I,which is compiled from data published by the American Society of Testing Materials:In addition, it is specified in an cases that the slabs shall be reasonably free from surface corrosion or adhering foreign matter. Although zinc used in Europe has in many cases been sold on analysis it is only recently that any attempt has been made to grade...

Jan 1, 1923

The industrial practice of separating finely' around valuable minerals from associ- ated gangue materials by froth flotation is well known. Despite the obvious importance of this industrial process, the predictive tools for plant engineering evaluation of flotation process variable changes are still in a developmental stage. Consider, for example, the situation where an operating engineer is faced with evaluating a change in an existing chemical reagent scheme, possibly based on batch laboratory data. When all is said and done, the engineer must still perform detailed physical testing of the proposed reagent change on the actual equipment in plant use to be confident even of the direc- tion of change of plant results, let alone the economic viability of the change. The theory behind chemical reagent behaviour in froth flotation has been studied extensively, e.g., (Aplan {1980}, Fuerstenau {1976}, Fuerstenau {1962}, and Somasundaran {1980}), and, certainly, important progress has been made. Unfortunately, the nature of the flotation process, with its complicated heterogeneous surface chemisty activity operating on highly variable and difficut to characterize ore surfaces, coupled with com- plex mass and momentum transfer phenomena, :;l riously compromises the plant scale predictive capability of theoretically based models.

Jan 1, 1978

Research cruises dedicated to seafloor hydrothermal activity along the Kermadec arc first began with the Sonne-135 expedition in 1998. This was followed by the worldÆs first systematic survey for venting along an arc during the 1999 NZAPLUME I expedition. Since then, cruises dedicated to mapping plumes along the Kermadec arc include NZAPLUME II (2002), NZAPLUME III (2004) and ROVARK (2007). In addition, the manned submersible cruises SWEEP Vents (2004) and NZASRoF (2005) utilised the Shinaki 6500 and Pisces V, respectively, to sample in detail select hydrothermalsystems for mineralised samples, rocks and vent fluids. The ROVARK (2007) cruise was the first to deploy an autonomous underwater vehicle (ABE) along the arc which surveyed Brothers volcano at a far greater resolution than had been done previously by ships on the sea surface. While these expeditions have largely been led by GNS Science, together with its collaborators from National Oceanic and Atmospheric Administration, Pacific Marine Environmental Laboratory (NOAA/PMEL), significant contributions have been made by other groups from various nations, exemplifying the global interest in seafloor hydrothermal activity associated with intraoceanic arcs. This is an ASTRACT only. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By C I. Edwards

Phosphorous is typically present in iron ore either in the mineral apatite, Ca5(PO4)3OH, or associated with the goethitic fraction of the ore. In this paper, we present results that show that phosphorous associated with the goethitic fraction can be removed with a heating pretreatment around 300 176;C for 1 h, followed by a caustic leach with 1 - 5 M NaOH, or a leach with sulfuric acid at pH 0.5. The heating pretreatment is considered to dehydroxylate the goethite to form a haematite intermediate phase, ‘protohaematite’, that reacts during the leach making the phosphorous accessible to the leachant. In the acid leach, ten to 15 per cent of the sample was dissolved to obtain a leach product with 0.08 per cent P. In the caustic leach, as no weight loss occurs, it is proposed that iron species associated with the protohaematite have either not dissolved or have reprecipitated at the high pH values of the leach.For an ore containing apatite as the source of phosphorous, a leach with sulfuric acid dissolved the apatite, lowering the phosphorous levels in the sample. The sample treated contained carbonate minerals (including siderite) that also reacted with the acid, and in practice a balance between the dissolution of the apatite and the carbonate minerals may be needed to minimise acid consumption.

Jul 11, 2011

By S H. Sie, R Seetharam, K Naito, T Takagi

Tin-polymetallic vein type deposits are one of the major source of metal producers in the Circum Pacific Belt. This type of deposit is of great importance for the modem electronics and medical industries because of their high content of rare metals (especially indium and bismuth). We have studied two representatives, Tosham of India (Cu-In-Bi-Sn-W-Ag-Au), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), using proton and electron microprobes in order to delineate the distribution of medicallhigh-tech rare metals. The electron microprobe study showed that major indium carrier in such type of deposit are roquesite (CulnS2), sphalerite, stannite and a Cu-Zn-Fe-In-Sn-S mineral; and that indium is incorporated in sulfides by coupled substitution like Cu + In = 2(Zn + Fe). The proton microprobe showed that indium at trace levels is also present in chalcopyrite and pyrite. In addition, zinc, copper, arsenic, antimony, selenium, tin, and bismuth are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are higher in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is genetically related to S-type magma, while the Mount Pleasant deposit is related to A-type granite. Tosham ore contains zinc-bearing biotites that coexist with chalcopyrite in ore bodies but Mount Pleasant ore lacks such biotite. We propose that the difference in elemental abundance between the two deposits are caused by the different character of source magma and different mineral associations of the ore body.

Jan 1, 1995

By M Ogle

"Booster fans are relatively rare in Australian coal mines. However, as mines become progressivelydeeper it is likely that such fans will be increasingly adopted as a method to sustain or improve the ventilation of underground workings. The reasons why booster fans may be an att ractive alternative include: increased cost of sinking additional ventilation shafts with greater seam depths; environmental objections to shaft sinking projects; and increasing urbanisation and surface constraints limiting availability of potential ventilation shaft sites. As Tahmoor Colliery movedinto its northern lease the ventilation constraints became the limiting factor on production. Thelimitations of the old workings meant that the existing ventilation system would be inadequateto sustain the required production. Extensive ventilation modelling was carried out to evaluatevarious potential solutions and the recommended option was the installation of a booster fanor fans, to gain underground access to an already approved shaft site in the northern lease.Proposals were sought from recognised fan manufacturers and various alternative arrangements were tendered. Ultimately the choice was between one large centrifugal fan and a set (three or four) of smaller æauxiliary-likeÆ fans in parallel. The successful tender was for a single centrifugal, an arrangement very similar to the booster fans that have been operating eff ectively at Westcliff Colliery for a number of years. This paper describes the current ventilation network, evaluation of the ventilation options, the fan selection process, and the project status to date."

Jun 1, 2012

By S C. Barrie

St BarbaraÆs Marvel Loch operations have successfully used longhole open stoping as the primary mining method for a number of years. A transition to Core and Shell mining was implemented in 2009 to recover substantial ore grade resources remaining in sill and rib pillars. The transition to core and shell for the Exhibition lode required continuous waste filling of created voids and thus the removal of the crown pillar at the base of the Exhibition pit by blasting. Access to the top of pillar was denied as the pit was partially rock filled with waste rock from underground development.Beyond the technical challenges of the blasting project, a simple and transparent risk management process was developed to ensure appropriate controls and mitigating strategies were in place to minimise risk to personnel during the pillar removal process.Although failure of the crown pillar was anticipated but with the actual timing unknown, on 25 December 2011 the crown pillar yielded during normal mine operations. Engineered and isolation controls in place at the time were of a sufficiently high standard to ensure limited exposure of the underground workforce and minimal damage to mine infrastructure. Successful risk management through implementation of appropriate controls during the project lifecycle of two years and three months proved to be fundamental to the safe removal of the crown pillar.CITATION:Barrie, S C, 2012. Successful risk management through project life cycle for removal of the crown pillar at the Marvel Loch Underground Mine, in Proceedings International Mine Management 2012, pp 125-134 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

Increasing use has been made of engineer ing geology and hydrogeology in the development of the infrastructure for mining projects. The Geological Survey of the Department of Mines, the Department of Main Roads, the Irrigation and Water Supply Commission and private consulting organisations and mining companies, employ spec- ialist staff to carry out engineering geological and/or hydrogeological investigations. Such in- vestigations have been of assistance in recent mining developments in northern Queensland, in- cluding those in the Cloncurry - Mount lsa, Weipa, Greenvale and northern Borten Basin areas.

Jan 1, 1974

By Napitupulu P

PT Freeport Indonesia currently operates a concentrating complex capable of milling 127 000 metric tonnes per day of copper and gold hearing ore. The facilities consist of both a conventional crushing, ball mill and flotation circuit and a SAG, ball mi

Jan 1, 1997

By Bodnaras G. E, Sceresini P. A

The Filblast Cyanidation Process incorporates the advantages of intense high shear mixing, high dissolved oxygen concentration and high pressure to achieve extremely rapid gold dissolution rates. This is made possible by the unique design of the Filblast gas shear reactor. The reactor is a rugged and compact in-line device. The outer casing is protected by a polyurethane coating and the internal parts are of wear resistant polymer. The largest unit built to-date has overall dimensions of 1200 mm length by 300 mm diameter and has a capacity of 150 dry tonnes per hour at 40 - 45 per cent solids. Service life at this throughput is at least three months. The process may further be applied to high temperature leaching of refractory gold ores or other metals. Wear resistant metal or ceramic materials would be employed for this duty. Four mines are currently employing the Filblast Process for treating a variety of ore types ranging from highly reactive, almost impossible to treat, pyrrhotite/arsenopyrite to deeply weathered clay ore which forms a highly viscous pulp. The effect of shear thinning has resulted in improved adsorption kinetics resulting in higher carbon loading and reduced soluble gold loss. Total tonnage treated is approximately four million. Operating costs which include leasing and maintenance charges for the Filblast and pump power costs are about 16 cents per tonne. This is equivalent to about ten per cent of savings. Laboratory scale units having capacities up to 30 litres/min are available for test work but laboratory testing techniques so far developed do not accurately reflect the oxygen and cyanide savings which have been achieved in the plant.

Jan 1, 1994

By W P. Breytenbach

"The phased application of statistical process control (SPC) infers that processes are classifiable as pre-SPC (or phase zero), phase I and phase II processes, with different objectives being pursued in the different phases. Phase zero processes, defined as processes affected by assignable causes of variation, are characterised as follows: out-of-control with unknown autocorrelation structure having an unknown statistical distribution not performing consistently on target with minimum variability potentially incapable of conforming to the product specifications. The objectives of phase I SPC is to obtain estimates of the mean (µ), variance (s2), probability density function (f(X)) and the autocorrelation structure, as well as transforming the process into a phase II process (defined as a process conforming to specifications and performing on target with minimum variability). As in any other type of research or pragmatic improvement intervention, sampling is required is to achieve these objectives. The challenge of deciding a phase I sampling plan is multifarious since it has to cope with the aforementioned effects of assignable causes and provide for rigour estimates of the unknown parameters. Furthermore, deciding sampling plans in phase I invariably presents a classical catch-22 situation: appropriate sampling is required to determine the autocorrelation structure of a variable, but knowledge of the autocorrelation structure is required to formulate an appropriate sampling plan. This paper suggests, for random variables, guidelines to formulate sampling plans, and presents a methodology to estimate the inherent process parameters of process variables and an approach to identify assignable causes in phase I. CITATION:Breytenbach, W P, 2014. Rational sampling and standard deviations for random variables in phase i application of statistical process control, in Proceedings Sampling 2014, pp 141–154 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 29, 2014

By Reilly L, Worner H. K

The EnvIRONment process has been developed to treat steel works dust and organic wastes simultaneously. A pelletised feed is fed into a special DC electric furnace, the pellets becoming immersed in a molten slag above a carbon saturated bath. The iron oxide in the pellets is reduced and carburised whilst the organics are broken down to carbon monoxide, carbon dioxide, hydrogen and water vapour. Volatile metals are vapourised and collected in the baghouse. Over two years of trials in a 100 kg DC electric are furnace has brought the process to the stage where it is ready for commercialisation.

Jan 1, 1995

By C A. Foss, D A. Clark, D Hillan

While magnetic surveys are the most common geophysical method used in mineral exploration, magnetics and geology remain to be fully integrated quantitatively in iron ore provinces. Although high-resolution aeromagnetic data has been collected over prospective areas of the Hamersley Province, much of the information in the data sets has hitherto not been fully exploited due to a lack of suitable interpretation methods. Recent advances in the processing and modelling of magnetics in highly magnetic terrains, constrained inversion and 3D visualisation and understanding the magnetic properties of banded iron formations and iron ores potentially create the capability to generate realistic 3D mapping of magnetite and hematite concentrations over large areas. Initial processing of conventional total magnetic intensity data produces true potential field maps that are unaffected by local perturbations of the regional geomagnetic field direction by intense local anomalies. The true potential field can be converted into vector and tensor components, each of which emphasises different structural features of the geology. Scalar quantities derived from these components simplify interpretation, using new methods, developed by CSIRO and elsewhere, that are less sensitive to magnetisation direction. Preliminary interpretations allow interpolation between mapped units and structures and evaluation of remanence and anisotropy effects. Accurate modelling requires rigourous treatment of self-demagnetisation and magnetic interaction effects. Semi-automated constrained inversion, combining magnetics with available geological information and other geophysical data, can be utilised to generate models of disposition of major magnetic units and the 3D magnetisation distribution within them. The final stage of interpretation is to exploit the understanding of magnetic properties (susceptibility, anisotropy and remanence) developed over many studies by CSIRO, the University of Western Australia and others to convert the interpreted magnetisation distributions into 3D maps of magnetite and hematite contents, which are the quantities of direct exploration interest.CITATION:Clark, D A, Foss, C A, Austin, J and Hillan, D, 2015. Three-dimensional mapping of magnetite and hematite concentrations from reprocessing of detailed aeromagnetic data, in Proceedings Iron Ore 2015, pp 229–240 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By D Lozada, A Salazar

Geometallurgy is a tool that, for more than a century, has been present in the implicit operations of mineral beneficiation. There’s a need to understand the characteristics of the material to be processed. This has led metallurgists to ask geologists what type of rock and mineralogy is entering the Beneficiation Plant and vice versa. The geologist needs to understand the beneficiation process in order to be able to carry out the production programming. The paradigm is whether geometallurgy can be applied to small-scale mining or if it is only aimed at large companies that invest millions of dollars to conduct studies. With this work, we provide an example of how geometallurgy can help improve the processes of a small mining company located in Ecuador (South America). We performed characterizations of geological and mineralogical and metallurgical tests in universities and the National Research Institute of Geological Metallurgical Mining. The origin of the theme is based on the fact that gold has been detected in the final tailings. The flotation concentrates meet the standards in terms of the content of economically profitable metals, but this isn’t the case with regards to the percentage of arsenic, which has hindered sales. The hypothesis is: conducting technical and scientific research will optimize the metallurgical process for the recovery of gold and concentrates. The referential framework is the mining geology of the Bella Rica District, current status of the Beneficiation Plant. In the theoretical framework there are parameters of the veins, comminution operations, gravimetric concentration, flotation, and cyanidation. The methodological framework contemplates the characterization of the gold ore, the chemical, mineralogical, textural, metallurgical analysis and the interpretation of the results. Thus, the design of a geometallurgy model of the deposit, with its main characteristics, is a conclusion that serves as a basis for the proposal of the optimization of the metallurgical process.CITATION:Lozada, D and Salazar, A, 2018. Geometallurgy applied to small-scale mining: a case study, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 153–162 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By T D. H McGrath, G Wardell-Johnson, E A. Oraby, W Staunton, A R. Bax, J J. Eksteen

"Gold ores often show significant inter-domain variation with respect to the gravity recoverable gold (GRG) content and the leach behaviour of the non-GRG component. Liberation assessment is extremely difficult for gold due to its malleability and the high sampling errors and poor test reproducibility resulting from gold’s high specific gravity and the low metal concentrations that occur in most gold ores. The use of microscopic techniques for the liberation assessment of gold is also impractical due to the high number of sampling errors and high cost of analysis.Curtin University’s Gold Technology Group has developed an online carbon-in-pulp/carbon-in-leach (CIP/CIL) simulation model called SIMCIL, which has been used since 1999 to model and simulate industrial leach-adsorption circuits. Recently the model has been upgraded to include an integrated liberation-leach modelling (ILLM) approach, which can be used to evaluate the impact of various process parameters (such as grind size, bleed to gravity etc) and circuit configurations on leach-adsorption circuit behaviour and overall plant gold recovery. A new time-efficient ore characterisation methodology has been researched and developed to provide the required liberation-leach data used in the ILLM approach, which is implemented online for the modelling of gold operations. The ILLM characterisation methodology, test work data analysis, interpretation and application of the ILLM test work data are discussed.CITATION:Bax, A R, McGrath, T D H, Eksteen, J J, Staunton, W, Oraby, E A, and Wardell-Johnson, G, 2016. An Integrated Liberation-leach Model and Ore Characterisation Procedure for Gold Ores, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 315–320 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By J Rayo

Andean countries (Chile, Peru, Bolivia and Argentina) have 42 semi-autogenous mills (SAG) in operation and there are more than 30 projects in the pipeline that consider SAG mills. At the end of the next decade, the total amount of SAG mills in this area will likely be close to 100.There is a lot of reliable operational information collected by JRI Ingenieria Sociedad Anonima, the author’s engineering company, for more than 20 years and processed by statistical software, to be used as a reference for design basis of future projects or to improve operations by comparison. JRI Ingenieria Sociedad Anonima has reliable information related to the performance of more than 50 per cent of the Andean SAG plants.The paper presented considers a set of graphs that summarise the collected and verified SAG plants technical data. The figures will show key parameters as circuits and equipment data, energy consumption, technical availability, utilisation rates, throughput variability, pebble productions, steel consumption and others.The data is compared with typical design basis of several engineering companies and the main differences are analysed and/or commented on.CITATION:Rayo, J, 2014. Comparison of semi-autogenous mills operations in Andean countries, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 283–296 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By Huleatt M, Perkin D, McLeod I, Mock C, Pratt R, Gourlay A, Timoney E, Knight N, Ward J

Generally speaking, Australia's reserves of its more important minerals (in terms of export earnings) are adequate to sustain forecast rates of production to the year 2000. The rate of forecast production increases of these commodities (aluminium - whether as bauxite, alumina or metal, black coal, iron ore and ferro-alloy minerals, base metals, tin, uranium, and mineral sands) reflects a well- ordered and sustained growth phase of Australia's mineral industry.

Jan 1, 1981

By Taylor MN

The influx of an industrial environment into or adjacent to the indigenous society has in the past frequently caused the breakdown of traditional be- haviour and culture, and the generation of social and psychological impacts on the local population. Successful programmes developed by government agencies and private industry have been implemented in many areas to maintain the cultural environment and still afford the needs for industrial development. The ultimate goal of such programmes should be directed toward eventual operation and management of the established industry by the local population.

Jan 1, 1978

By Laird CH

Large quantities of brown coal are excava ted from open cut mines in the Latrobe Valley to fire the base load thermal power stations of the Victorian Electricity System. Most of the coal is removed using bucketwheel excavators which have been modified or specially designed for the conditions encountered. The actual digging efficiency of the bucketwheel excavator is strongly influenced by such factors as wheel speed, slewing speed and tooth design and arrangement. The coal deposit, although not difficult to work, is not uniform and the operation of the machine is influenced by the stability re- quirements of the excavation face.

Jan 1, 1978

By Colston M. B, Johnson I. D

The importance which matters of social welfare and environmental quality have assumed recently is the underlying theme of this paper. Demands for infrastructure reflect the change in emphasis from economic and technological development to those issues which affect the total well-being of the community. To put the importance of social change in perspective, examples are cited and a theme is developed which underlines the relevance of changes in public attitude and in government policies on mineral exploitation and related development and on the regimen of associated infrastructure sought. Planning on a long term or strategic basis and on a broad scale is put forward as an effective means of identifying changing social attitudes for the purpose of framing government and corporate policies. As a prelude to a section in which a description is given of a novel 'services baseline' concept and its use in the assessment of the current backlog of services

Jan 1, 1977