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The copper-clay deposits consist largely of goethite and clayey mudstones carrying native copper, cuprite, and chalcocite. The mudstones are of Ordovician age, are interbedded with Fe-Mn carbonates, and probably contained syngenetic iron and copper sulphides. The secondary copper minerals have been derived from post-Devonian weathering in situ and also by deposition from surfaee and underground waters draining the adjacent mineralized volcanic rocks.

Jan 1, 1969

The ultraviolet spectrum of isopropyl ethylthionocarbamate (the principal constituent of Dow flotation collector Z-200) in water and of Z-200 itself in water was found to have an absorption peak at 242 nanometers(nm). The height of this peak was found to be directly proportional to isopropyl ethylthionocarbamate concentrations up to 15 p.p.m. Z-200 contains about 90 per cent isopropyl ethylthionocarbamate and the heightof the peak was proportionately lower, but obeyed the straight line relationship up to 15 p.p.m. This showed the potential value of spectrophotometric measurements for the determination of Z-200 residuals in flotation liquors.Methyl ethyldithiocarbamate (an impurity in Z-200) increased the peak height slightly, but other impurities in Z-200, xanthates, and most inorganic salts present in flotation liquors do not interfere. However nitrate ion and thiosulphate ion have absorption peaks which overlap the isopropyl ethylthionocarbamate peak.The simplest general method to overcome this effect is to extract the isopropyl ethylthionocarbamate into cyclohexane and to measure the absorbance of the extract.The maximum absorbance of the cydohexane extract was at 247 nm and the peak height at this wavelength was found to be directly proportional to the isopropyl ethylthionocarbamate or Z-200 concentration in the original aqueous solution. An alternative method is to measure the spectrum of the original aqueous solution using the aqueous raffinate from extraction as a reference solution. This gives the spectrum due to isopropyl ethylthionocarbamate alone and measurement of the absorbance at 242 nm gives the concentration in the original aqueous solution. Both methods give the same value for the concentration of isopropyl ethylthionocarbamate in the original solution.

Jan 1, 1969

By A D. Campbell, G R. Power

Many caving mines use numerical flow models to simulate mine production, forecast recovered ore grades and optimise the draw strategy. In sublevel caving (SLC) mines, the effects of blasting and fragmentation at an individual ring scale generally cannot be included in these models. Previous attempts to use results from marker recovery trials to calibrate numerical flow models have been limited due to difficulties in accounting for blasting effects at a ring scale. This paper outlines how an empirical criterion for blasting and fragmentation was used to attribute variable flow properties into a numerical flow model based on the blast design and modelled fragmentation. The flow model was then validated using data from a number of full scale marker recovery experiments. The result of this approach was a significant improvement in forecast accuracy when compared against the same modelled cave marker recovery without the inclusion of these blasting effects. Improvements in the flow model are currently being adopted within the mine scale model to further improve the accuracy of grade forecasting, optimise the draw strategy and increase net present value. The integrated modelling approach is also being used to simulate the effects of different drill and blast designs on cave recovery. It is suggested that, if implemented, the technique would lead to improved blast designs in other SLC mines, increase the value of marker trial data and reduce costs associated with large scale blast design trials.CITATION:Campbell, A D and Power, G R, 2017. Improving calibration of flow models against SLC marker trials by linking blasting effects to particle mobility, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 11–22 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

Beneficiation of Iron Ore - Washing with Surface-Active Agent The stability of the dispersed phase in 10 wt per cent slurry of iron ore slime and fines was studied at pH 5 and different concentrations of surface-active agents. The behaviour of the dispersed phase of iron ore slime and fines is different for different surface-active agents. The improvement of iron value of slime and fines in the presence of surface-active agent is best realized at pH 8, where the Al2O3/Fe and Al2O3/SiO2 ratios in the concentrates are appreciably reduced. The polar functional group like -COO- interacts with hematite surfaces and forms outer- and inner-sphere surface complexes depending on the suspension pH and adsorbate.

Sep 13, 2010

By Keet B. A, Waid J. S

The Gippsland Basin is one of Australia's most important producers of petroleum products. An inevitable byproduct of the production, refinement and transport of the millions of barrels of oil is thousands of tonnes of waste. These wastes are generated from the wellhead through to the petrol bowser and range from oily brines and coal tars to oil and petrol contaminated soils. The vast majority of these wastes are of a relatively low toxicity and most importantly are carbon-based and biodegradable. Current disposal practices tend to ignore the latter characteristic and inappropriate and/or expensive waste disposal solutions such as landfilling (tipping), incineration or ocean outfalls are the result. A very cost effective and environmentally friendly alternative is land treatment of such wastes. Landfarming, as it is called, has been successfully practiced in Europe for over a decade. Essential features of the system are: ò Application of a predetermined quantity of biodegradable waste in liquid, sludge or highly contaminated soil form, to pre-ploughed soil with concurrent addition of nutrients (N, P and trace elements) and lime to encourage bacterial activity. ò Harmless bacteria already present within the soil break down the carbon-based compounds into carbon dioxide, water and waste heat, WHILE concurrently generating new cells. The breakdown occurs over a period of weeks to months and continues with time with the extremely low levels of the more difficult waste types being the last to disappear. ò Further waste is applied to the soil at regular intervals. The treatment area may be dedicated to landfarming or may be used alternatively for agricultural purposes. Application rates vary but may be as high as 800 tonnes per hectare per year for wastes such as refinery sludges.

Jan 1, 1992

By Parkhurst D. H

It is shown that a differential colorimetric technique can be used as a routine method for the estimation of titanium in beach sands, and their ore dressing products. The method will tolerate the presence of most of the other elements usually found in beach sands. The accuracy is shown to be within the limits of ±0ò31 per cent for concentrates containing more than 95 per cent titanium dioxide and ±1 per cent for tailings containing 0ò2 per cent titanium dioxide. The method is described for use with a Hilger "Spekker" absorptiometer.

Jan 1, 1957

Grade control is a real challenge, and better sampling and modelling practices are among the tools that have proven efficient in improving it. Although based on rather trivial examples, this paper addresses the following important issues: How much of a challenge is it? How and to which degree can it be improved? And what kind of economic benefits should be expected in return for the corresponding efforts?

Jan 1, 1999

Near-Infrared Spectroscopy (NIRS) Sorting in the Upgrading and Processing of Skorpion Non-Sulfide Zinc Ore In 2008 Anglo American sponsored a research project at RWTH Aachen University to assess the feasibility of the use of near-infrared spectroscopy (NIRS) for ore waste discrimination at the Skorpion zinc mine. The Skorpion mine is an open pit zinc mine located in Namibia, owned by Anglo American with an annual production of 150 000 t/a of super high grade pure zinc. Opportunities for the implementation of NIRS sorting for the Skorpion process exist to upgrade currently subeconomic material, including the marginal dump (over 2000 000 tonnes, av grade of 2.5 per cent Zn). NIRS sorting is not yet implemented or established in the minerals industry however it is a proven technology in the plastics recycling industry, where more than 2000 NIRS sorters have already been installed. NIRS sorting, a type of sensor-based sorting, is a single particle sorting technique which classifies the particles based on the absorbed/reflected radiation in the near-infrared (NIR) region. A disadvantage of NIRS is that it is a surface measurement technique, but NIRS sorting shows overall great potential for the minerals industry. Skorpion ore minerals include zinc bearing phases such as sauconite, hemimorphite, smithsonite, and hydrozincite. These display diagnostic responses in the near-infrared. There are three major absorption features that characterise the reflectance spectra of the ore bearing minerals. These are due to OH and H2O molecular bonds. The spectral response of the waste material is caused by other minerals such as non-zinc-bearing clay minerals, calcite and impure quartz. Test work showed that it is theoretically possible to separate ore material from most waste material based on spectral response in the NIR region. In addition to upgrading material by removal of waste it is also potentially feasible to classify the material based on zinc grade. A tentative correlation between zinc grade and spectral response seems to exist for the sample test suite in the NIR region.

Sep 13, 2010

Perhaps one of the most important conferences or symposia which our Institute has conducted, was the joint Aus. LM.M./AJ.M.E. meeting held in Canberra in May 1978, with the theme International Resource Management (Woodcock, 1978).We were privileged to witness active participation in the meeting by outstanding personalities from the mining and metallurgical industries of Australia and New Zealand, the United States of America, Canada and the United Kingdom and to hear addresses on subjects of international significance to the mining and metallurgical industries.Our Institute is one concerned with professionalism.The principal objects of The Institute as described by our founders include, "promoting the arts and sciences connected with the economical production of the useful minerals and metals, and the welfare of those in the industries, by meetings for social intercourse, and the reading and discussion of professional papers, and to circulate by means of publications amongst its members and associates, the information thus obtained".Sir Maurice Mawby (1968) said in his Presidential Address to the Institite, "the most important aspect of these objects was the promotion of the arts and sciences of the mining industry".Why is it then, that a large proportion of the papers given at the meeting in Canberra dealt with world wide social aspects of the mining and metallurgical industries, rather than the technology, the arts and sciences of mining and metallurgy as principal factors in international resource management?The answer is quite simple of course, and that is that the social and political factors are the principal factors which create the demand for basic raw materials and in the long term determine the costs and prices of the commodities which our professional abilities are drawn upon to produce.

Jan 1, 1979

Importance of Strain to Fragment Strength in Blasting Induced Pre-Conditioning When a rock is blasted, cracks propagate through the rock causing the rock to fracture. This paper focuses on applying the results from a series of small scale blasting tests were designed to show the effect that varying blast variables such as explosive type and explosive energy have on the resulting strength of the post blast fragments. It was shown that the velocity of detonation of the explosive product affects the reduction of fragment strength. This has important implications for the downstream comminution process. The observations from these tests are then explained with reference to the principles of fracture mechanics. A simple but effective prediction of blast induced preconditioning is shown.

Sep 13, 2010

By D Rubery, C Croker

The Boddington Gold Mine (BGM) is located 120 km south east of Perth, Western Australia. The operation is managed by Worsley Alumina Pty Ltd and mined by contractor Henry Walker Eltin (HWE). The mine has been operating since 1987 with ore extracted from a series of pits along strike. Ore is contained within the basement rock, which is overlain by a cap rock layer and transition zone. Cap rock and basement zones require blasting.As the mine neared completion, a high-grade deposit was discovered within 50 m of an existing Western Power substation and 100 m from the processing mill. The substation provides power to the Boddington area and is a back-up power supply to the city of Perth. Due to the delicate nature of the transformers located at the power station, overhead power lines and the mill, blasting in the area was considered very high risk. As such blasting needed to be controlled for flyrock, airblast and most importantly peak vibration and frequency limits which had the potential to damage the transformers.The mine was due for closure in March 2001. The decision to mine the pit was based on its high grade, ability to be blended with lowering grades from other pits and changing of the processing technique with the expansion. This decision extended the life for a further six months.Due to the high potential risks a detailed risk assessment was conducted by Orica, Worsley and Henry Walker Eltin. The completed assessment and the major design parameters were presented to Western Power for approval. The ability to reduce the blasting risk was focused on limiting of vibration through controlling maximum charge initiated per delay, blast timing and firing direction, and other innovative control measures. OricaÆs SHOTPlan« and Sabrex« computer modelling packages were used to predict the outcome of blasts.The success of this project has opened the doors for other high risk blasting projects, which otherwise may be left unmined.

Jan 1, 2002

By Fardy J. J

Abundance data are presented for a comprehensive range of elements in oil shale samples from deposits located in Queensland. The techniques of instrumental neutron activation analysis and spark source mass spectrometry were used to obtain concentration data for up to 50 trace elements in each shale. These techniques were supplemented by other spectrometric methods to obtain data for major, minor and some trace elements. Sixty-four elements were determined quantitatively. This comprehensive characterisation of oil shale samples from the major deposits in Australia provides inorganic abundance data not previously available. It also provides important background information for processing studies and the associated environmental aspects of shale oil production and waste disposal.

Jan 1, 1986

By Ruxton B. P, Rhodes J. M

Two Rb-Sr ages are discernible in data concerning the leucocratic granite which is the youngest pre-sedimentation phase of the crystalline basement complex at Rum Jungle, Northern Territory, Australia. Whole-rockdata suggest that intrusion of this unit took place at about 2400 my ago, with a probable initial ratio around o·707; whole rock-potassium feldspar tie-lines indicate redistribution of strontium at about 1800 my ago. The former age correlates with other measurements on rocks which form basement to the mantling Pine Creek Geosyncline; the latter correlates also with isotopic evidence for regional metamorphism and emplacement of some younger intrusive granites elsewhere within the geosyncline. A few K-Ar ages, from scattered localities, conform generally with the later event or events which appear to have some connection with the structural deformation clearly observable both in the complex and the surrounding metasediments. It is these younger events which appear to match the residual evidence for the earliest detectable concentration of uranium minerals in the Alligator Rivers district.

Jan 1, 1977

By D J. Corp

The Halmahera Contract of Work is a sixth generation contract held 82.5 per cent by Newcrest Mining Limited and 17.5 per cent by PT Aneka Tambang and takes in the Gosowong Project area. In 1991 Newcrest Mining Limited established a small exploration office in Jakarta and proceeded to seek exploration opportunities. The Halmahera area was identified as a substantial prospective ground position in a relatively unexplored area. In late-1991 Newcrest Mining Limited and PT Aneka Tambang agreed to explore in Halmahera. Initial field work commenced in July 1992. A vigorous ground reconnaissance programme led to the discovery of the Gosowong deposit a little over 12 months later in September 1993. In April 1997 the Contract of Work was approved covering much of the island of Halmahera. Between September 1997 and November 1998 activities were directed principally towards obtaining the necessary permits required to commence construction activities. Some particularly ambitious targets were set for achieving this outcome. An aggressive construction programme commenced in late-1998. Construction took place during a period of unseasonally high rainfall, which in itself presented additional challenges to the construction team. A key milestone for the project was achieved on 1 July 1999 when wet commissioning of the process plant commenced. Construction of the Gosowong Mine was achieved on time and within budget. A period of some six years elapsed from the initial discovery of the Gosowong deposit to the time of the first gold pour. Much of the permitting, construction and commissioning activity took place between September 1997 and July 1999. This coincided with a period of significant social, economic and political upheaval in Indonesia. During the construction period a high level of importance was placed on the structured recruitment and training of local people, as well as fostering appropriate community and local business development programmes in the communities nearby the project. Emphasis was also placed on environmental management with detailed long-term planning and progressive rehabilitation commencing during the construction phase. The permitting and subsequent development of the Gosowong Project has demonstrated that even during the difficult times, with commitment, it is possible for mining and exploration companies to conduct business in Indonesia.

Jan 1, 1999

Automation in underground mining enhances safety and leads to economic efficiency. In the past many efforts have been made on the automation of longwall shearer operation. With respect to the ultimate goal of automation, ie self controlled operation, coal bed boundary detection is one of the key problems. For longwall human labor is necessary in order to detect the exact position of the coal seam to be excavated. The authors present a sensor concept based on infrared technology and pattern recognition which will solve this problem. The very harsh underground conditions set high demands on the implemented sensors. The combination of infrared sensors and powerful processing algorithms is part of the innovative concept for automation of the new Eickhoff Bergbautechnik GmbH SL 750 shearer loader. The multi-sensor automation system EiControlPlus which is designed for the complete detection of the machine environment fills in the gap in the coal-excavation automation by building a recognition system that turns the shearer loader into an 'intelligent machine' which is capable of detecting the correct position of the seam to be excavated and thus enables human-free coal mining.

Dec 6, 2010

By E V. Kislov

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Northern Baikal Ni-Cu province is located in Buryatia, south-east Siberia, and geologically is part of the Baikal-Muya volcano-plutonic belt. It is known for numerous PGE-Ni-Cu-bearing mafic-ultramafic intrusions of Neoproterozoic age formed in various geodynamic settings. All these deposits can be regarded as a single Ni-Cu ore cluster located near the Kholodninskoe Pb-Zn deposit, which is ready for mining. In addition, there are less studied, small dyke-like bodies with sulfide mineralisation that formed in a rift setting and may be enriched in Ni, Cu and PGE. Individually, the known bodies are of poor commercial value by their resources, but their close spatial association (<30 km) may make these PGE-Ni-Cu deposits economic in the future. This extended abstract seeks to provide a geological framework of the North Baikal Ni-Cu-PGE province, specifically at the north-eastern Synnyr rift hosting numerous small subvolcanic bodies with Ni-Cu sulfide mineralisation. Some small subvolcanic bodies contain industrial level Ni-Cu deposits (Shanuch, Cabanga-Musongati, Voisey’s Bay, Jinchuan, etc).CITATION:Kislov, E V, 2015. North Baikal region Ni-Cu deposits , in Proceedings PACRIM 2015 Congress, pp 297–302 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By S Reid, W Chen, T J. Donohue, A Katterfeld

The use of discrete element modelling (DEM) is widespread in the materials handling field, and is used for many applications. One of the important limitations in using DEM is the number of particles that can be modelled, with this limitation often resulting in increasing the minimum particle size in the simulation. This restriction on minimum particle size is usually accommodated in the calibration process where the parameters in the simulation are chosen in such a way as to reflect the presence of smaller sized particles, and in typical applications such as transfer chutes this is standard practice. However, in the application of vibrating screens the inclusion of the ‘fines’ is critically important due to their influence on the screening efficiency. In reality, the presence of fines reduces the screening efficiency for a number of reasons; however, the main mechanism that will be addressed in this study is the effect of adhering fines. This is where the fines adhere to the larger particles and are carried over into the lump stream. The approach for this study will be to firstly consider the relatively simple mechanical sieving process used in the determination of particle size distribution, and then this will be expanded to consider the application of vibrating screens.CITATION:Donohue, T J, Chen, W, Katterfeld, A and Reid, S, 2017. Addressing the challenges associated with the modelling of iron ore in vibrating screens, in Proceedings Iron Ore 2017, pp 155–160 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Despite technological improvements and better understanding of the hazards, coal dust explosions stilI occur. Experimental explosions in galleries in various countries extend knowledge with the constant aim of providing safer working conditions. The inadvertent ignition of an accumulation of methane is the traditional initiator of the coal dust explosion.There are specific parameters of coal dust explosibility and explosion propagation, including the important volatile matter in the coal, fineness and dispersibility of the dust and its concentration. Accepting that initiation cannot be absolutely prevented, it is necessary to consider explosion suppression. While both limestone dust and water are the chosen explosion suppressants, in practice water has more limitations to its efficacy when related to the degree of explosion violence. These data give rise to the criteria for explosion suppression, differences in favoured mining geometries, and using the same principles, to differences in suppression treatments.

Jan 1, 1988

It is now five years since the advent of gold-dredging in Australia, the State of New South 'Wales, or colony as it was, being the first to adopt this system of gold-getting, and the credit of its introduction rests with a member of this Institute, Mr. Chas. L. Garland, who commenced operations with his dredge on the Macquarie River, at the junction of the Muckerawa Creek, in the month of March, 1899. In this paper it is intended to give a brief history of the career of the gold dredge in New South Wales from that relate up to the present time, during which period the writer, as a designer of many dredges, has been constantly in touch with the subject in all its phases in this State; the points noted are the outcome of his observation in a general way, and to a great extent are apart from the design proper.Gold-dredging in New South Wales up to the present moment can hardly be designated an unqualified success...

Jan 1, 1904

Though many mining and mineral processing companies have embraced the principles of sustainable development (SD), there is still a significant challenge of applying these in a practical sense, either in plant design or as part of day-to-day operations. The high-level nature of sustainability concepts often do not translate easily into workable activities or business case evaluations. This makes it difficult for engineers and company decision makers to understand whether their actions are making a contribution to sustainable development and a long-term business case. While several organisations have their own SD tools that can, to a degree, help identify these opportunities, they are largely ad-hoc and lack the necessary thoroughness to defensibly value these opportunities. Recognising these serious shortcomings, the Cooperative Research Centre for Sustainable Resource Processing (CSRP) has undertaken the development and trial applications of SUSOP« (SUStainable OPerations), a new concept that is somewhat analogous to HAZOP and the wider risk and safety frameworks used in projects today. The key goal of the SUSOP« research project is to produce a holistic, systematic and rigorous framework for project development, capturing, recording and evaluating SD opportunities and constraints against a chosen sustainability structure (eg Five Capitals). SUSOP« is being developed through an iterative process with input from research institutions and engineering companies. This integrated approach ensures that SUSOP«, in its final form, will have the academic rigour and industry realism required to assist the resource sector contribute to societal sustainability by embedding the concepts and processes into the design and operation of their assets in a meaningful and practical manner. SUSOP« has created much traction with both engineering companies and mining and minerals operators. This conference paper presents an overview of the SUSOP« framework and its current suite of processes as well as highlighting, through practical case studies, its capability to incorporate SD considerations at different phases of an engineering project's development.

Jun 1, 2010