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Variations in product distribution in the carbon-sulphur dioxide system due to variations in reaction temperature, sulphur dioxide concentration in the feed gas, and gassolid contact time were studied in detail for a brown coal char. The results were compared with those for two wood chars, a coke prepared from Liddell coal and two cokes prepared from Ac1and coal. Conditions were chosen such that gas-solid diffusion rates did not hinder chemical attack of the carbon.With brown coal char under suitable conditions, the selectivity of sulphur in the sulphur dioxide fed, to either elemental sulphur or carbon disulphide, was in excess of 90 per cent. The wood chars gave very similar product distributions Ito brown coal char. However, the cokes from Ac1and and Liddell coals were respectively approximately three and seven times less reactive than the brown coal char.The approximate carbon holdup required to just achieve total conversion of sulphur dioxide, and thereby achieve high selectivity to elemental sulphur, is given as a function of reaction temperature.

Jan 1, 1974

A review is made of the limited published experience of the effects of cemented fill in flotation.A general approach is adopted in listing and discussing possible sources of, and reasons for, ore contamination by cemented fill, together with basic, fundamental approaches to minimizing this contamination. These approaches involve basic mining design, effect of fill placement density, optimization of curing time and of cement content, variation of fill particle grading, use of flocculants and of pozzolans, fill placement and dewatering, and or blasting and handling practice.

Jan 1, 1974

By G Wyartt

Systems such as Davey Bickford’s Daveytronic® SP blast initiation system and electronic detonators have been an integral part of drill and blast activities in Australia for over a decade, with the significant benefits of electronic blasting well documented. Since 2010 the Multiblast feature has been commercially available, which enables eight individual blast patterns (up to 1500 detonators each) to be blasted in the same firing window. Synchroblast has been in active operation since 2012, which allows a blast of up to 4500 detonators – either as a single blast pattern, or several smaller adjacent blast patterns – to be reliably initiated.Multiblast manages blasts separately but concurrently, allowing all blasts to conduct prefiring checks simultaneously from the firing point utilising only one remote blasting unit. Each blast can be selected and fired individually, in a sequence determined by the operator by scrolling through the colour display. Synchroblast automatically detects the blasting configuration, and manages all detonators as a single blast pattern. This simplifies the design and blasting processes for the mining operation.Multiblast and Synchroblast are routinely employed throughout Australia and globally in both open cut and underground operations, enabling optimal productivity due to increased blast volume and reduced operational downtime associated with blasting events.A number of case studies will be presented in this paper, detailing various mining operations that are consistently blasting in excess of 2500 detonators per blasting event as a part of standard drill and blast operations. Blasts over 3000 detonators are becoming more frequent as mine planning departments adapt to this operational capability and flexibility.CITATION:Wyartt, G, 2017. Multi and Synchroblasting – maximising operational productivity, in Proceedings Iron Ore 2017, pp 631–634 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Johnson N. W

After an unsuccessful transfer from the laboratory to the pilot plant of galena flotation technology which used sodium metabisulphite and ethyl xanthate, laboratory flotation tests were conducted to identify any unusual variables which had a deleterious effect on the position of the lead rougher grade recovery curve for Hilton and Mount Isa silver-lead-zinc ores. Two variables (pulp temperature and contact time for ethyl xanthate and sodium metabisulphite) had important deleterious effects.The findings allowed a successful transfer of the laboratory process to a pilot plant scale process. The effect of temperature was important because the higher temperature (40°C) in the pilot plant pulp increased significantly the rate of reaction between ethyl xanthate and sodium metabisulphite. In the laboratory process at 20 to 25°C, the reaction rate was lower and did not interfere significantly with the process. The contact time for the two reagents was also important in the pilot plant scale process because of the higher reaction rate at 40°C.To employ ethyl xanthate in the pilot plant process, special precautions were required. Further, a collector (Aerofloat 241) from the dithiophosphate family was used successfully in the pilot plant process.

Jan 1, 1988

Residual aeolian placers (RAPs) are formed by the wind, by preferential entrainment and removal of small and low-density detritusfrom a pre-existing, typically sedimentary sequence containing heavy minerals. Heavy minerals that are resistant to chemical alteration and either soft and malleable (gold), or extremely hard (diamond, sapphire, ruby, etc), are concentrated as a residual on the wind deflation surface, typically in the interstices between larger resistant clasts. RAPs form preferentially in arid or semi arid areas, where the vegetation is sparse or absent, and where topography and surface gradients are low, but may also form on beaches and in periglacial environments. RAPs consist of a continuous or discontinuous, planar or gently undulating horizon of heavy minerals in a single-clast-thick pavement of resistant pebbles, cobbles, or boulders, which mantles the present topography or palaeo-topography. Extreme wind erosion and surface deflation may condense the full pre-existing sequence into a layer of heavy minerals only. The grade of RAPs is substantially higher than in the precursor deposit, and commonly much higher than those typically found in most other placer types. Aside from their general occurrence as a thin pavement of resistant clasts, the best indicators of residual aeolian gold placers are the presence of wind-eroded stones (ventifacts) on the pavement, and the distinctive and unique shapes of aeolian gold grains themselves. The shape of the gold grains is progressively transformed by sand blasting during placer development, from grains with thickened rims, to toroidal grains on which the rims are æsplitÆ and peened inward toward the grain centre on one or both of the grain sides, to hemispherical or sub-spherical grains that are fully encapsulated by the in-turned rims. Gold that has undergone aeolian shape transformation is difficult to entrain and transport away from the site of aeolian concentration by anything other than mass movement or glacial processes. It is also easily retained by commercial recovery plants of any configuration.

Jan 1, 2004

The Effects of Collector and Grinding Environment on the Flotation Selectivity of Rosh Pinah Pb/Zn Ore

Sep 13, 2010

By A Giblett, R Dunne, D Appelhans

There are a number of hurdles that must be negotiated in order to design an effective gold ore treatment facility such that the expectations forming the basis of project economics are valid and can be achieved in practice. Selecting samples based on geometallurgical context, performing and interpreting testwork relevant to the selected process flowsheet are essential considerations towards achieving this aim. This paper discusses recent experiences in process development for free milling gold ores giving consideration to frequently encountered challenges of this nature.CITATION:Giblett, A, Appelhans, D and Dunne, R, 2013. Considerations for effective gold process development, in Proceedings MetPlant 2013 , pp 445-454 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

The Mount Angelo prospect outcrops as two copper rich gossans, the larger of which is 250 ft long and 70 ftwide. The mineralization is epigenetic and replaces part of a brecciated and disturbed lime tone and calcareou sediment sequence.Magnetic and self potential survey indicated a substantial body of sulphide mineralization, the top of which was approximately 100 ft below the surface.Diamond drilling confirmed this and established the presence of a mineral body of at least 500,000 tons, extending to a depth of 300 ft. Of the 500,000 tons, 200,000 ton are primary copper ore which a ays 2 per cent copper.This mineral body is not economic at present, but could become economic if copper mining is established elsewhere in the district...

Jan 1, 1966

By K Gordon

A methodology for assessment and remediation of acid mine drainage (AMD) developed at the Sullivan Mine in the West Coast Region has been applied to the closed Blackball Mine, Blackball, West Coast Region. AMD from the Blackball Mine has low pH, high acidity, and elevated levels of iron, aluminium, manganese, nickel, zinc and arsenic. The AMD flows at a variable rate (36 - 101 L/s) into adjacent Ford Creek, causing an increase in acidity and trace element concentrations in the creek. To test the effectiveness of treatment with a simple limestone-based treatment system, a column leaching experiment was conducted over a nine day period. The results show effective removal of acidity, reduction in the concentrations of iron, aluminium, manganese and zinc, and production of alkalinity. To determine if this treatment method reduces the toxicity of the AMD to aquatic invertebrates, a 96 hour ecotoxicity experiment was conducted. The results show a significant decrease in mortality in the treated AMD compared to untreated. The column experiment, in conjunction with the ecotoxicity work, suggest that a passive treatment system consisting of a limestone leaching bed and an open limestone channel may be sufficient to treat the AMD from the Blackball Mine. Further work, such as large-scale treatment trials, is recommended.

Jan 1, 2004

Most analysts determining tungsten trioxide in low grade samples are aware that colorimetric procedures do not possess the inherent disadvantages of gravimetric methods operating on milligram quantities of tungsten trioxide. Apart from the inaccuracies associated with weighing four or five milligrams of ignited oxide in a platinum crucible of about 30 gm. weight with a large surface area to absorb moisture, using a 5 gm. charge on samples less than about 0·15 per cent tungsten trioxide, it is extremely difficult toget complete or pure precipitation of tungsten with cinchonine, cinchonine plus alpha benzoin oxime, rhodamine B or any other of the commonly used precipitants. Table 2', No. 8, illustrates the low results obtained by gravimetric as opposed to colorimetric procedures. In addition the colorimetric determination requires only a small portion of the time consumed by gravimetric practices and the increased accuracy obtainable in low ranges together with the saving in time made it highly desirable to develop a colorimetric method suitable for King Island ores.The most commonly used colorimetric method is that introduced by Feigl and Krumholz (1932), since modified by various investigators (Grimaldi and North, 1943; Sandell, 1946; Westwood and Mayer, 1947; Gentry and Sherrington, 1948; Freund, Wright and Brookshier, 1951; Grouthamel and Johnson, 1954; and others). Stannous chloride is used to reduce tungsten followed by colour development with a thiocyanate, usually sodium, potassium or ammonium.Other reducing agents have been proposed (Emery and Curtis, 1948), but only in recent years have the conditions governing maximum colour development been fully estab...

Jan 1, 1958

This is what I term ... the graveyard end of any Conference. It's almost over. Those of you remaining are either all talked out or past the information overload stage. And some of the sensible? ones have left for more exciting field trips, or gone back to their work-site where they earn their daily crust, or headed off South to another Conference of interest to the Energy sector that is being held currently in Christchurch. But that's OK. I have a thick skin! And neither am I particularly Politically Correct! I am not a miner: I am not involved in the mining industry in a hands on way at all. I am not even an academic. I am not even too sure why I am here ... apart from the fact that I agreed to come! At various times in my life I have been a D istrict Councillor, Chairman of a Regional Council and even an MP. I am a supporter of responsible mining.  All of what I have to say is my own point of view rather than that of either the Coal Producers' Federation or the mining industry. That is not to say that we are often in agreement, but I thought I would clear that point right at the outset. And some of what I will talk about will not strictly be to the topic - it's hardly mind-bending riveting stuff. Well, is it? But obviously because you are still here you have some interest in the topic.

Jan 1, 1997

By R Bertuzzi

This paper presents a three-dimensional analysis of a trapezoidal-shaped segmental tunnel lining for a recent tunnelling project in Sydney. Two- dimensional analyses, hand calculations and equipment selection defined the lining geometry and loads. The analysis, which was undertaken using 3DEC (Itasca), included a complete ring of six segments bolted together to assess the impact of imperfectly built rings. Asymmetry was induced in the analysis by unfavourable positioning of segments within construction tolerances. Model output includes displacement and stress within the entire ring and normal, shear and bending moments at the joints. For the case analysed, the results suggest a 10 mm construction tolerance increases normal and shear stresses along the radial joints by approximately 25 per cent and 15 per cent, respectively and up to a doubling of the induced moments.

Jan 1, 2008

The GPS and information technology industries are now applying considerable development effort to what is being termed machine control and machine information systems, in particular focusing on the industries the of mining construction and agriculture. GPS based systems are demonstrably finding common acceptance and adding commercial value to many machine applications in industry. This has been the first step in the evolution of the information age that is now reforming mining practices. Adding the technologies of wireless data communication, modem computer databases, and networked PC's mining is on the verge of a new era in overall process management. This paper is a general discussion of what the information age means to miners and a general description of new mining operation technologies available to day from the Caterpillar technology alliance.

Jan 1, 1999

Since the last occasion on which I spoke to you on this subject there has been a considerable increase in the mechanical ventilation of Western Australian mines.The following table compares the figures for 1939 with those of 1941. The type of fan most commonly used is the limit load fan. On account of its higher mechanical efficiency it has very largely superseded the multivane fan with forward curved blades.Two fans of the propeller type are in use and these have given very satisfactory service. This type of fan also has a high mechanical efficiency particularly at the correct duty for maximum efficiency.The maximum efficiencies obtainable from the various types are, for "multivane" 670/0, for "limit load" 75%, and' for aerovane 7810/0.References to propeller fans with variable pitch have appeared in the technical press, but no detailed d~scription has been issued. The advantages of these fans for mine ventilation are not obvious. An aeroplane is required to operate over a wide range of duties, while the speed of the motor for maximum efficiency is pl'actically constant. In such circumstances the propeller can be adapted to the particular work it has to do by varying the pitch of the blades. In a mine the speed of the fan can be varied to suit.the conditions, and it would appear that variable pitch is not necessary while there is a reasonable range of fans to choose from.The question of the correct position for the fan still comes in for considerable discussion. Exhausting fans at the surface have the support of time and custom, and in many cases this represents the only reasonable arrangement. Such fans should be fitted with an evase, especially in the case of fans with a high outlet velocity such as the aerovane types.It is claimed that there are advantages in having the fan at the surface where it is readily available for inspection and maintenance. Experience has shown that these advantages are more apparent than real. Fans will run for long periods with no attention other than occasional greasing and cleaning, and modern electric motors will run without attention for very long periods.In some instances the expense of a power cable to take current to the fan may be saved by placing it on the surface, but in the majority of cases...

Jan 1, 1941

By R L. Brathwaite, S E. Belliss

Linear and semi-circular features were mapped in the volcanic terrain of the southernCoromandel Peninsula, North Island, using JERS-1 synthetic aperture radar (SAR), Landsat-4 Thematic Mapper, and SPOT-2 multispectral satellite data, digital elevation models, and aeromagnetic data. The mapped features typically correspond to recognised physiographic features and are thus a useful aid to mapping the structural trends in the region. Major linear features exhibit a strong N-S to NNE-SSW alignment, and lesser NW-SE and NE-SW trends. All these are superimposed on pervasive, closely spaced, NNE-SSW and NNW-SSE lineaments present over most of the hilly parts of the map area. There are few major E-W aligned features. Some alignment trends correspond to strike directions of veins in the epithermal gold-silver deposits of the region, but none of the known mineralised structures were visible on the remote sensing data.   The volcanic rocks are Late Cenozoic in age and include a variety of rock types: andesite and dacite flows, domes and tuff breccias, rhyolite domes, tuffs and tephra, lacustrine siltstones, and ignimbrites. Mapping of different textures in the SAR image failed to provide additional information on rock types to that derived from the Landsat and SPOT images. A simple discrimination of rock units based on radar texture is apparently prevented by the complex volcanic geology, superimposed hydrothermal alteration, and long period of erosion.

Jan 1, 1994

Modelling and simulation are important aspects of flotation research, which may assist in the design of new circuits and the optimisation of existing ones. Flotation research in the AMIRA P9 project has developed a methodology for flotation plant modelling based on determination of cell (pulp) characteristics. froth characteristics, and ore floatability (using floatability components). The implementation of this methodology requires the determination of ore floatability, to which end a small flotation pilot plant known as the Floatability Characterisation Test Rig (FCTR) has been designed and then built and kindly made available to the AMIRA P9 project by Baker Process. The FCTR has a 2 tph capacity and consists of six 130 litre rougher/scavenger cells and six 50 litre cleaner/recleaner cells. The Mintek FloatStar pulp level control system is used to control the pulp level in all cells. A number of experimental procedures have been developed for using the FCTR to obtain the data required for the P9 flotation models. These procedures include how to determine the floatability parameters, Pi and mi, the bubble surface area flux, Sb, the mean residence of the pulp in the cell, t, water recovery. Rw, froth zone recovery, Rf, and the degree of entrainment, ENT. The flexibility of the FCTR allows it to be used in numerous flotation studies such as stream characterisation, reagent testing, grinding experiments, power studies, oxidation studies, and scale-up and simulation studies. This paper will describe the design and operation of the FCTR and the procedures that will be used to obtain data from the rig for modelling purposes.

Jan 1, 2000

A short account is given of the theory and practice of determining the true U3O8 content of ore samples by the determination of the beta and gamma activities separately, using the method of Eichholz and his associates.It is shown that, despite the variation of sample activity without change in U3O8 content, the true U3O8 value can still be found.Thorium can be determined simultaneously if this element is also present.

Jan 1, 1957

By Y Cai, B Hebblewhite

In this paper, the Australian thick coal seam underground mining potential is highlighted and the characteristics are investigated by analysing a thick seam database. It is clear that thick coal seam resources should be mined with a high recovery, productive, efficient as well as a safe and reliable mining method. Longwall Top-Coal Caving (LTCC) is the most recent thick coal seam mining method which has been developed and extensively used in China for the last ten years. The successful applications indicate that this method has a very high recovery and productivity rate and less development cost in comparison with any other thick coal seam mining method. One of the aims of the current study is to seek potential for the application of LTCC as a thick seam mining method in Australia. In this paper, preliminary results of investigation on Australian thickseam potential are given and results of data analysis for potential LTCC seams in Australia are described. The outcome of this study shows a great promise for the application of LTCC in Australian coal industry.

Jan 1, 2002

By D Preedy, J K. Claflin, S R. La Brooy

A gold mine in north-eastern Africa has expanded throughput from 5 to 10 Mt/y in recent years. The original carbon regeneration kiln was incapable of achieving required throughput or meeting process conditions to reactivate the carbon due to heavy fouling by high molecular weight frothers and collectors. A new high temperature kiln was required.The design criteria for the carbon reactivation kiln and associated equipment were revised, then implemented in close cooperation with a kiln vender who had previously supplied kilns operating successfully on highly fouled carbon. The result is a whole facility, holistically designed to achieve the technical criteria.The new carbon reactivation facility has been operating since 1 July 2014. What have we learned? What has performed to expectations? What could be done better?This paper presents lessons learnt regarding the design, implementation, operation and maintenance of the Ausenco Carbon Reactivation Kiln. ‘Lessons’ are associated with threats and opportunities (risks) that have that have been realised. The importance of identifying and managing risks for even small straightforward projects is demonstrated.CITATION:Claflin, J K, La Brooy, S R and Preedy, D, 2015. Lessons learnt and performance – installing and commissioning an Ausenco carbon reactivation kiln in Africa, in Proceedings MetPlant 2015, pp 163–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

A consideration of mining ventures and the changes of an environmental nature that occur. The paper is introduced with a general statement claiming recognition that mining ventures are important to human well-being but that these need to be justified against the environmental changes that they bring about. The various factors that need to be considered are cited followed by an historical review of mining activities. The various environmental issues are discussed under three headings; socio-economic, physical and biological, prior to reviewing the world's demand for minerals including fossil fuels. In conclusion guidelines for appraising mining ventures relative to environmental changes that may occur, are given.

Jan 1, 1981