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By Wilson G. L, Lord J. H

A detailed analysis of faulting indicatcs that blocks of "greenstone" have been thrust beneath the southern end of the Mt. Isa orebodies.This "greenstone" basement is considered to be a major structural control in the localization of these orebodies.INTRODUCTIONThis paper is based on exploration carried out by Mining Corporation (Aust.) N.L. from 1956 to 1960 in the area immediately south of Mt. Isa, Queensland. During this period over 20,000 ft of diamond drilling was completed together with costeaning and geochemical exploration.Early in 1959, it became apparent that diamond drill information could not be correlated with the current geological concepts of this area and a detailed geological appraisal became necessary. In all, sixty square miles were mapped at a scale of 1 in. to 500 ft, using enlarged aerial photographs. All drill core was logged and sections re-interpreted.Professor K. C. Dunham of the University of Durham consulted on this project and contributed through valuable discussion. Dr. A. Day of the University of Sydney carried out a gravity survey in February 1960 and Dr. H. Wilshire of the same University undertook microscopic examination of rocks from the area. Certain sections of the area were investigated geochemically by Mr. K. K. Hughes of New Consolidated Gold Fields (Asia) Pty. Limited in 1960.In outlining a theory of ore genesis in the area the writers have drawn heavily on the invaluable data published by many previous workers on the Mt. Isa field, in particular...

Jan 1, 1963

By S Moradi

The aim of this study was to investigate the possibility of leaching zinc from the tailing (-2 mm) of Angouran flotation plant using sulphuric acid. The tails were first calcined at 800¦C for one hour. The effect of factors such as stirring rate, temperature, initial acid concentration and solid/liquid ratio, on zinc extraction were studied. The results obtained show that at the best conditions, about 91 per cent of zinc were leached using a stirring rate of 800 rpm, a reaction temperature of 50¦C, a 30 minute reaction time, a 100 g/L initial sulphuric acid concentration and solid:liquid ratio 1:6 g/ml. The P85 of the feed material was about 150 ¦m and acid consumption was 600 kg/t.

Jan 1, 2002

The sulphides can be arranged in a series determined by the relative amounts of ionic and covalent bonding present. This series is similar to the paragenetic series common to most sulphide ore deposits. Investigation of the surface tensions of the corresponding heavy metal iodides by the maximum bubble pressure method throws some light upon this relationship. It is shown that the surface tension of molten iodides decreases as the chemical bonding within them becomes more covalent. These results are interpreted in terms of the constitution of the melts, and are extended to cover the case of sulphides in solution in a silicate melt. It is concluded that sulphides tend to lower the surface tension of silicate melts and that this tendency becomes greater as the bonding within the dissolved sulphide groups becomes more covalent. A possible relationship between this conclusion and the origin of paragenesis in sulphide ore deposits is indicated.INTRODUCTIONIt is well known that the order of deposition, or paragenesis of sulphide minerals is remarkably similar in hypogene ore deposits throughout the world. This widespread similarity points towards the operation of some fundamental process which must be intimately connected with -the genesis of these ores. A correct interpretation and understanding of the causes of paragenesis in sulphide ore deposits would shed much light on the origin of these deposits.In Table 1 a simplified paragenetic series for sulphide minerals is presented. In most cases, only the most important sulphide of any particular element has been included. The object of this procedure is to simplify the following discussion. Furthermore, it should be realized that this series is only a generalization and that exceptions and reversals of position are quite common. Especially does this...

Jan 1, 1956

Whilst much has been written in past years by geologists, scientists, mining engineers, etc., regarding the well·known and justly notorious anticlinal, or, as they are more commonly known, " saddle" reefs of Bendigo, comparatively little noticehas been given to the synclinal or "inverted saddle "reefs and their relationship with each other. In taking up the question of the synclinal folds, I recognise that it is a large undertaking to confine within the limits of a short paper, and at the same time convey a comprehensive idea of their characteristics, and the importance of their relationship with the anticlinal folds, in the general question of practical mining. However, from a practical point of view I consider the question of great importance, and if an interest in it can be awakened, more particularly among practical men, the object of this paper will be achieved.Before entering into the subject I must briefly state some facts, and perhaps some theories, in respect to the deposition of the Lower Silurian rocks, and their subsequent buckling up, as now seen on the Bendigo gold-field. At the same time, I do not intend to go very closely into the geological aspect of the question, as I wish the paper to be considered as a practical one.

Jan 1, 1902

By the use of flotation tests it was confirmed that there are two functions of oxygen in sulphide mineral flotation. Sized samples of galena and chalcopyrite were sulphidized, washed free of excess sulphide ion, and then contacted with air-saturated water for certain lengths of time. The mineral was then transferred to a sealed laboratory flotation cell containing water with a known concentration of dissolved oxygen. Xanthate and frother were added and flotation continued for 1 min.Both the extent of mineral oxidation and the concentration of dissolved oxygen markedly affected the flotation of galena and chalcopyrite. The response to a change in either variable is dependent on the level of the other, but generally best flotation occurs with the maximum degree of air saturation of the pulp. Galena flotation is hindered by oxidation of the mineral beyond a small threshold amount but a similar effect for chalcopyrite was not observed...

Jan 1, 1967

By D Craw, K A. Hunter

Deposits of the metalloids arsenic and antimony occur in quartz veins of mesothermal hydrothermalsystems in the South Island as arsenopyrite (AsFeS) and stibnite (Sb2S3). Arsenopyrite and stibnite occur in natural exposures in gold-mining areas, and additional arsenopyrite and stibnite have been exposed to the atmosphere by mining activity. At present the drinking water limits for dissolved As and Sb are 10 ppb and 3 ppb respectively. Sampling and analysis techniques are critical to determination of metalloid concentrations at these low levels. Endeavour Inlet in the Marlborough Sounds is an historic mining area (late 19th Century) with elevated As and Sb in waters emanating from mineralised rocks. Waters running out of abandoned adits have concentrations of As and/or Sb up to ppm levels. Natural waters have high Sb and low As, and the As levels increase markedly where anthropogenic activity has exposed rock. Changes in Sb/As ratio could potentially be used to quantify the anthropogenic component of metalloid mobility on mine sites on the 100-year time scale.

Jan 1, 2002

By A Hekmat, M Fuentes, F Armijo, R Castro, F Rodriguez

Interpreting the behaviour of granular material and simulating the gravity flow are complex processes in cave mining methods. In this paper, a new Cellular Automata based code – FlowSim – is used as a flexible tool to simulate the gravity flow and subsidence zone in block caving mines. The simulation results of the gravity flow model in a real scaled mine as well as a scaled physical model are presented in this study. In this research, FlowSim was first calibrated at a mine, based on the information obtained from smart markers. These markers were located in five points of the second block of the Esmeralda sector, at the El Teniente copper mine, Codelco, Chile. The calibration was performed with the objective of reducing the discrepancy between the extraction zone defined by markers in the mine and FlowSim outputs. Regarding the mine data, FlowSim was calibrated with the minimum error of ten per cent between real and simulated results. Then, the calibrated FlowSim model was used to simulate the flow behaviour of a scaled physical model. This model was constructed in the Block Caving Laboratory of the University of Chile to scale down the same block of the Esmeralda sector with the scale of 1:200. The FlowSim outputs show that this software enables the simulation of the gravity flow of the scaled model with less than five per cent discrepancy in grade and dilution entry to the drawpoints. According to the obtained results, this paper recommends FlowSim as an appropriate tool which can improve the design of production level in block caving and can enhance the prediction of the subsidence zone and dilution entry.CITATION:Castro, R, Hekmat, A, Fuentes, M, Armijo, F and Rodriguez, F, 2016. FlowSim – a versatile flow simulation tool to quantify extraction and design alternatives for block caving, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 645–652 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

Inhibition of Bubble Coalescence by Salts and Sugars

Sep 13, 2010

By S Chew, A Bennett, N Di Giorgio, B Osborne

After relining one of two blast furnaces and enlarging its sinter plant in 2009, BlueScope radically restructured its Port Kembla steelworks operation in 2011, shutting a blast furnace and halving its total production. This drastic move in response to unprecedented raw material prices relative to achievable steel prices was like that of many integrated steelmakers worldwide facing similar challenges. The 2011 restructure also saw major changes in the amount and type of iron ores and ferrous burdens purchased, and a fundamental reappraising of ‘value’ in iron ores. This paper outlines the changes to raw materials purchases from 2011 to 2017, how BlueScope has responded to the changes in pricing and raw materials quality, the effect on the sintering and blast furnace processes at Port Kembla resulting from higher gangue content, some of the broad technical and economic challenges faced by steelmakers confronted with lower quality iron ores and how BlueScope is meeting those challenges.CITATION:Di Giorgio, N, Bennett, A, Osborne, B and Chew, S, 2017. Recent Port Kembla experience with iron ore use – sintering and blast furnace, in Proceedings Iron Ore 2017, pp 25–30 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Z S Chang, T F. Zhou, G X. Zhong

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Yaojialing zinc-gold polymetallic deposit is a newly discovered, large skarn deposit in the Middle-Lower Yangtze metallogenic belt, East China. It is located in the transitional zone between the Tongling uplift block and the Fanchang faulted basin. It is mainly hosted in the contact zone between early Cretaceous granodiorite porphyry and Carboniferous-Triassic limestone, or occurs in limestone xenoliths within the intrusion. Skarn and stratabound massive sulfide orebodies are the primary ore styles. Sulfide ?34SV-CDT values indicate a magmatic sulfur source, in common with most deposits in the Tongling block. Calcite d13CV-PDB and d18OV-SMOW ratios reveal that marine carbonates were the major source of carbon in late-stage hydrothermal fluids. The calcite probably formed during interaction between magmatic fluids and carbonate wall rock.CITATION:Zhong, G X, Zhou, T F and Chang, Z S, 2015. Geology, chronology and isotope geochemistry of the Yaojialing zinc-gold deposit, Tongling ore district, Anhui Province, China, in Proceedings PACRIM 2015 Congress, pp 457–462 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Study on Mineral Processing for a Cassiterite Ore in Southwest China

Sep 13, 2010

By D Craw, P Upton

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Southern Alps of New Zealand and the mountains of Taiwan are both young transpressive orogens characterised by rapid uplift and exhumation, high heat flow and vigorous surface processes. Comparing and contrasting the two provides an ideal framework through which to explore the structural and lithological controls on fluid and gold mobility during collisional deformation. Both have two fluid flow systems centred about their drainage divide with shallow topographically-driven meteoric water above a deeper flow system dominated by mineralising rock-exchanged fluids. Despite similar tectonic settings, the distribution of heat flow, hot springs and veins in the two orogens are different. Taiwan has higher heat flow, distributed hot springs and localised veining whereas the Southern Alps have a narrow heat flow anomaly, localised warm springs and widespread veining. We use three-dimensional numerical models to evaluate key parameters that affect fluid flow and gold mineralisation. Models show that differences in crustal strength and thickness affect the locus, scale and rate of crustal fluid flow and hence influence gold deposition at a variety of scales. We explore how surface topography can lead to localised changes in the stress state, facilitating the switching of principal stresses and hence vein orientations.CITATION:Upton, P and Craw, D, 2015. Modelling structural and lithological controls on the mobility of fluids and gold in orogenic belts – examples from New Zealand and Taiwan, in Proceedings PACRIM 2015 Congress, pp 189–192 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

The Takasima Coal Mines comprise four islands near the entrance to Nagasaki Harbour, and are owned and worked by the Mitsu Bishi Company.There are several unusual features in the occurrence and working of these coal seams, the steep angle of "dip," the numerous seams of good coal separated by hundreds of feet of sedimentary rocks, the extensive faulting of the strata, and the way in which the coal is won, when so little surface is available for works, and where there is the ever present danger of subsidence of the roof and consequent flooding of the workings by the ocean. The author trusts that short notes on these few points will be of interest to members.The Islands are named respectively Hasima (Extreme Island), Nakanosima (Middle Island), Takasima (High Island), and Yokosima, and are situated about one mile from the main land.

Jan 1, 1901

By G Mark, K L. Blake, G de Jong, J F. Rotherham, N D. Adshead

Magnetite deposits with distinctive ¦ actinolite ¦ apatite-bearing gangue and spatially-extensive sodic-calcic wall rock alteration occur in both Proterozoic metamorphic terrains and Mesozoic-Tertiary magmatic arcs. Examples from both settings constitute significant sources of iron ore (egKiruna, Sweden; El Romeral, Chile) and some host major Cu-Au deposits that have a local association with K-silicate alteration (eg Cloncurry district, NW Queensland; Copiapo district, Chile). A growing body of evidence points to a hydrothermal origin for these systems involving high temperature, low S oxidised fluids. The Cloncurry magnetite-Cu-Au deposits are products of the local structurally channelised influx of a specialised high salinity ore fluid into larger-scale alteration systems developed during pluton emplacement at greater depths than those associated with subvolcanic (porphyry) Cu-Au deposits. The geological characteristics of deposits in magmatic arcs are consistent with a similar mode of origin albeit in rather different tectonic settings.

Jan 1, 1995

By M P. Simpson, J L. Mauk

The Golden Cross, low-sulfidation, epithermal deposit shows a number of features that are directly or indirectly related to boiling hydrothermal fluids. Occurrences of lattice calcite and their quartz pseudomorph equivalents in veins, and occurrences of adularia in veins and in the surrounding altered rocks in the vicinity of ore, are both direct evidence of deposition in the presence of boiling hydrothermal fluids. Loss of carbon dioxide causes calcite deposition (platy variety) near the level of first boiling, while adularia deposits due to the attendant pH increase along the cooling flow path. Indirect evidence of boiling include crustiform-colloform quartz banding, late massive calcite veins, clay-carbonate alteration in the shallow and peripheral parts of the ore zone, and the restricted vertical interval of precious metal mineralisation. The colloform quartz banding strongly resembles the banding in amorphous silica deposits found in geothermal surface pipes. This implies that fluids ascending the Empire Vein structure were saturated in amorphous silica. If so, then they must have undergone phase separation, which initiated at considerable depth (e.g. =1000 m) and very hot temperatures (e.g. =300¦C). On the basis of stable isotope data, late massive calcite veins appear to have deposited from CO2-rich steam-heated waters. Calcite deposited along heating paths as these waters descended into the upflow zone during late stage collapse of the hydrothermal plume. In active systems, such steam heated waters form by deep boiling. The high CO2 contents of these waters promote hydrolytic alteration and the formation of clay-carbonate alteration. Reaction path modelling using CHILLER and a deep, Broadlands-Ohaaki water as an analogue, shows that minerals deposit along boiling flow paths over discrete spatial intervals. Calcite and adularia deposit near the site of first boiling, followed by gold and then by amorphous silica. For deep boiling starting at 300¦C, these minerals deposit over a path length that exceeds 1000 m. The distribution of banded quartz and gold at Golden Cross are consistent with such a boiling model. However, the elevation of first boiling must have fluctuated over 500 m to account for the coincidence of lattice quartz (pseudomorphs of platy calcite) and adularia, crustiform-colloform silica and gold over distances of a few centimeters in veins. We deduce that a downward propagating boiling front and expansion of two-phase flashing in a flowing water column occurred during episodes of high vertical permeability and fluid flux in the Empire vein structure.

Jan 1, 2000

Research and Tests on Improving the Technology of Enrichment of the Copper-Molybdenum Ore

Sep 13, 2010

By Waugh D. M

investigations have been undertaken into the flow characteristics of mineral slurries from a number of Australian metallurgical plants including Mount Isa Mines Ltd., North Broken Hill Ltd., and Broken Hill South Ltd. Experimental equipment installed for this work included facilities for continuous recording of flow rate and pressure drop and detection of sedimentation.Although the method has subsequently been described in published literature, it is believed that the investigations included the original application of a method for correlation of the flow rate and pressure drop data. This method depends on solving by graphical methods the values of the constants k, and c in the relationship EQUATION 1 where D is pipe diameter; ?P, pressure drop; L, length; and V, mean linear velocity. Discussion of this correlation also reveals why sedimentation velocity does not necessarily vary greatly with pipe diameter.INTRODUCTIONIn order to design pumps and pipeline installations for a Newtonian fluid, measurements of the fluid's density and viscosity in any of a number of instruments are sufficient. Substitution of these values in well known equations to calculate Reynolds numbers and subsequent correlation to determine friction factors are all that is required for engineering specification.As a result of work during the last decade, particularly that of Metzner and Reed (1955) and Dodge and Metzner (1959), it is now possible to design for homogeneous non-Newtonian fluids using relatively simple instrumental measurements.These methods can sometimes be applied to thick slurries which behave as if homogeneous. However, for the...

Jan 1, 1965

South Africa has joined the league of other major Western World countries by officially adopting its own code for public reporting of Mineral Resources and Mineral Reserves. The recently published South African Code for Reporting of Mineral Resources and Mineral Reserves (SAMREC Code or Code) (SAIMM 2000) is presented here in its local and global context. The main aspects of the Code are listed and elaborated upon. The Code has been written with the participation of the major South African stakeholders in the field including Government institutions, the legal confraternity and the mining industry. Relevant foreign organisations, such as the Australasian Joint Ore Reserves Committee (JORC) and the United Nations contributed to its compilation, and supported it. The Code thus enjoys endorsement both locally and, to a large extent, overseas. The Code is modelled on, and is 90 per cent compliant with, the Australasian Code for Reporting of Mineral Resources and Ore Reserves (JORC Code) (AusIMM, 1999). The paper also elaborates on the duties and responsibilities of Competent Persons signing off resource and reserve reports and on the new listing requirements of the Johannesburg Securities Exchange (JSE), formerly the Johannesburg Stock Exchange, which has officially adopted the Code.

Jan 1, 2002

By F Pirajno

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. China’s mineral deposits are the result of metallogenic processes associated with the geodynamic evolution of tectonic plates and eventual amalgamation into their modern configuration. The principal tectonic provinces of China comprise the North China Craton, Yangtze Craton, Cathaysia Craton, Tarim block, Altay-Tianshan-Hinggan orogens (part of the Central Asian Orogenic Bel), Central China orogens, Songpan-Ganze orogen and Alpine-Himalayan fold belts, which are part of the huge Tethysides. These tectonic elements are testimony to a complex geological history spanning more than 3000 million years. This contribution will focus on selected areas of the Altay-Tianshan, the fold belts surrounding the North China Craton and Yangtze Craton and the mineral systems along the Ailaoshan-Red River fault zone. Mineral deposits in these provinces include gold, copper, molybdenum, tin, antimony, nickel, platinum group elements, lead and zinc.CITATION:Pirajno, F, 2015. Metallogeny and related tectonic settings in China , in Proceedings PACRIM 2015 Congress, pp 17–24 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Declining metal prices over the last few years have reduced the number of new metallurgical plants being built and limited opportunities for introducing new processes. However, technological advances are still being made. With increasing economic pressures, the emphasis is now on reducing unit costs by making equipment larger and through use of technologies with lower operating costs. This trend can be seen in the increasing size of grinding mills and flotation cells used in recent plant designs and in the adoption of HPGR crushing as an alternative to SAG milling. Few new technologies achieve widespread introduction until there are clear economic or operational drivers. These might currently include: ò          increasingly stringent environmental standards; ò          availability of exotic materials for equipment construction; ò          increasingly sophisticated instrumentation and control systems; ò          the need to treat increasingly refractory oretypes; and ò          the length of supply routes to many new plants. As a result of these drivers, a number of new and revitalised technologies will get increasing prominence in the design of new operations, such as: ò          use of ultrafine milling equipment such as MIM's Isamill for treatment of refractory gold ore concentrates; ò          use of thiourea as an alternative for cyanide in sensitive locations; ò          novel hydrometallurgical routes for treating base metal ores in remote locations; ò          paste thickening for tailings deposition; and intensive cyanidation of gravity concentrate

Jan 1, 2000