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Two separate mine rehabilitation programmes carried out by Australian Consolidated Industries Limited (A.C.I.) in South Australia at Normanville and Port Lawler are discussed. Emphasis is given to the methods used, the results achieved and to possible future improvements.

Jan 1, 1976

By Happ J. V

Factors affecting the rate of arsenic removal from lead bullion during softening processes were studied. Very high rates of removal could be obtained under conditions of intense agitation and ready availability of oxidant. Reaction mechanisms were proposed to explain the sequences observed. Selective removal of arsenic with minimal loss of antimony from bullion was favoured by a low temperature Harris process and oxidizing via a caustic soda medium.

Jan 1, 1987

Bubble Load Measurements in Flotation - A Critical Review of Current Practice

Sep 13, 2010

Before proceeding I wish to say that the excellent diagrams by which my paper is illustrated are the work of Mr. C. H. Barnes, Constructing Engineer of the Kalgurli Gold Mines Limited, and I am also much indebted to Mr. F. A. Moss, manager of the mine and for the privilege piIling information not previously made public.The limited time at my disposal has coolled to, curtail the scope of my paper to a few practices in ore treatment which are being worked on the Kalgurli Mine, but which I believe are of more than ordinary interest to thp~e Goncerned in modern treatment of gold ores. As an introduction to my subject it is, necessary that I should give a brief outline of the process by whiGh the gold is won from the complex sulpho-telluride ore of the Kalguili mine.My business is not to enter into any discussion as to the relative merits of the two rival sulpho-telluride ore treatment processes at work on the Kalgoorlie field, viz, the treatment of the unroasted ore after shining by solutions of bromocyanide, as against the treatment of the ore-after roasting by solutions of potassium or sodium cyanide either in filter presses or percolating sand vats. Even if reliable costs and percentages of extractions were obtainable in each case, it would not constitute an infallible basis of comparison, as the larger plants would necessarily have an advantage in cost per ton as against the small plants, and the other conditions obtaining are in many Cases dissimilar.

Jan 1, 1903

Water retention, water loss and delay in tailings storage rehabilitation are major challenges for many Coal Mines. Work by Stewart, Backer and Busch in the early 1980s suggested that there were improvements to be made in tailings dewatering and density by the addition of flocculant. This prompted ACARP, in cooperation with Bulga Coal Management (Xstrata), to initiate a research project investigating the impact of flocculant addition on tailings deposition density, water retention and the tendency for tailings to form surface crusts suitable for subsequent rehabilitation. A polyacrylamide-based flocculant (200 - 250 g/tds) was injected into the tailings line immediately prior to disposal into the impoundment area. The flocculated slurry rapidly released clear water and created a beach due to the immediate increase in deposition density. The deposition density increased from 35 per cent w/w to 61 per cent w/w solids within 24 hours and continued to increase to 75 per cent, seven days after treatment. The water capture at the tailings storage facility improved by more than 90 per cent; water which would otherwise be lost from the circuit through retention and evaporation. The impoundment capacity had nearly tripled due to the improvement in initial deposition density from 420 kg/m3 up to 1163 kg/m3. Four weeks after disposal surface crusts were forming on the storage facility, suggesting that there would be less delay between cessation and tailings storage rehabilitation.

Jan 1, 2008

This paper contends that optimisation of energy resources through active control and predictive simulation modelling is possible, and that such monitoring leads to large savings in the electricity costs of hot mines (where refrigeration has to be employed). In addition, active monitoring and control can positively affect the establishment of a safe, healthy and productive working environment. In the entire optimisation process certain guidelines were set to ensure that the requirements of the Mine Health and Safety Act were met (South Africa). Varying the quantity of air supplied underground by means of variable speed drive (VSD) fans is one of the crucial factors in the interactive approach towards the optimisation of ventilation, as is refrigeration and the pumping requirements associated with refrigeration. This article highlights the interaction between the amount of air supplied and the effect it has on refrigeration requirements underground. This article also considers the effect that this would have on contaminant control. Various tools are available for ventilation and cooling design for mining. A lot of these tools are based on the assumption of steady state conditions and do not take into account instantaneous changes in conditions, day-to-day, or hour-to-hour (such as for temperature and contaminants). They also do not take into account the optimisation of energy resources related to the creation of the acceptable underground conditions. With these tools worst-case and best-case scenarios are identified, and strategic decisions are made accordingly. Currently, the amount of the fresh air, the velocity of the air, and its general temperature in the mine are only changed when one production phase changes into another (or when unacceptable conditions occur as a result of poor design or neglect). This means that during a specific production phase (which can last for several months), there can be an oversupply, or undersupply, of energy resources, which will obviously affect the concentration levels of the various contaminants (through under or oversupply of air).

Jan 1, 2005

THE de-silverizing of base bullion at the Port Pirie works is carried out in accordance with the principles of the well-known Parkes process. The base bullion produced by the blast furnace department carries (apart from silver values) impurities, the chief of which are copper, antimony, and arsenic. In order to more clearly indicate the grade of the base bullion, the following analysis, representative of a half-year's production of base bullion, is submitted...Before proceeding with the actual operation of de-silverizing, it is necessary that the impurities, copper, antimony, and arsenic, should be eliminated. This is accomplished in the following steps :- (1) Removal of Coppel - Copper is largely present in the base bullion as dissolved sulphide, and this is removed by liquation in a reverberatory type furnace, of which the following are the essential details :-Working temperature 7500 to 8500 C.Coal consumption per 24 hours 2 tons.The hearth of the furnace is encased in a steel tank 22 ft. 4 in. long by 13 ft. 4 in. wide by 2 ft. 10 in. deep; the bottom of the tank is covered by a depth of composition conforming to the invert :-Cement 39 cwt.Brick dust 8.4 tons.Fireclay 0.6 tons.Sand 0.6 tons...

Jan 1, 1922

By Cleghorn JH

Underground mining operations on Kalgoorlie's Golden Mile were suspended in 1976, suffering the combined effects of low gold prices and grades. A subsequent substantial increase in the gold price led to the decision by Kalgoorlie Mining Associates to reopen their mines in 1979. The two shafts selected for access required excessive maintenance. The geological assessment and development parameters prescribed have been successfully used to establish reserves to maintain production at a 390 000 tonnes per annum rate. While ore reserve grade is being maintained from primary stoping sources, supplementary lower grade ore is drawn from remnant pillars and stopes at lower cost.Performance by the workforce has reached levels previously attained and a record tonnage was hoisted in the fourth year after recommencement.Keywords : Golden Mile lodes, geological research, payruns, cut and fill, mill holes, gold price, ore grade, amalgamation.

Jan 1, 1984

By Matthew SP, Hayes PC

The product morphologies formed on the reduction of dense wustite crystals are classified into three types,A) porous iron, B) porous wustite covered with dense iron and C) dense wustite covered with dense iron. The mechanisms of formation of these structures and the effects of impurity elements on the product morphologies are discussed

Jan 1, 1984

By T Baumgartl, T Huynh, K Tungpalan, E Wightman, M Edraki, M Tayebi-Khorami, L Huang, S Palaniandy, E Manlapig

With the increasing rate of tailing production worldwide there is a growing concern about the hazards of tailings storage facilities (TSF). Past and current mining, processing and waste disposal strategies that focus on the extraction of the valuable minerals, and an economic assessment only, are no longer suitable. Social implications and environmental legacies must be included for effective evaluation. This is possible by using an integrated assessment framework to evaluate more alternatives, including the production of additional saleable and benign streams, alternative tailings treatment and disposal as well as options for reuse, recycling and preprocessing of existing tailings. Tailings are not viewed as a final waste product but as part of the resource. From the sustainability perspective the models developed in integrated research programs will contribute to more effective methods for assessing different scenarios and potential processes and lead to better environmental management, increased production of benign tailings and improved efficiency of water and energy use and thus more responsible resource stewardship of the ore resource.This paper presents preliminary results from a multiyear research program on integrated tailings management at the Sustainable Minerals Institute (SMI), The University of Queensland, called ‘Designer Tailings’. The project involves the gathering of experimental and observational information on tailings biogeochemical processes to design and modify the range of activities within mineral processing plants, upstream characterisation ore and gangue, and downstream tailings management for desired tailings properties and outcomes. This information will assist the development of new total integrated value chain CITATION:Edraki, M, Huynh, T, Baumgartl, T, Huang, L, Andrusiewicz, M, Tungpalan, K, Tayebi-Khorami, M, Wightman, E, Palaniandy, S, Manlapig, E, Evans, C, Farrokhpay, S, Bradshaw, D and Vink, S, 2014. Designer tailings – an integrated model for tailings management, in Proceedings Life-of-Mine 2014 , pp 599–608 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By P Hayward a, P Evans, K Prince, F Radke

Operating efficiency is becoming paramount as the mining industry moves towards globalisation and conglomeration. Mining companies are continuously searching for new technologies that can improve plant efficiency, by reducing operating costs and maximising metal recovery. Identification of how gold losses occur within an operating plant is crucial for determining appropriate operating strategies for improved metallurgical performance. Classical mineralogical and metallurgical techniques enable the operator to identify where losses occur in terms of particle size and mineral associations, however how the gold is hosted within the mineral grains (for example, as solid solution or as fine micro-inclusions) is more difficult to determine. This paper provides details of the testwork methodology, and resultant laboratory study to improve gold recovery.

Jan 1, 2004

By Flann R. C

A small modification to current industrial practice should lead to better nickel powders for use in alloying, electroplating, and powder metallurgy. Nickel powder compacts sold for alloying are not always suitable for electroplating applications, since some presently used commercial powders will expand on sintering. Further, such nickel powders are unsuitable for use in the production of powder metal parts, because of expansion during heating of the near-net-shape preforms. Research in these laboratories has enabled the elimination of expansion, and led to techniques for the production of compacts suitable, in particular, for commercial use in both alloying and electroplating. The techniques include: powder pretreatment, cold pressing and sintering, hot pressing, and hot pressing and sintering. In this way compacts are readily prepared with densities of at least 93 per cent of solid nickel, and these, when used as anodes in Watts general purpose and bright baths, give both cathode current and plating efficiencies of 90-98 per cent.

Jan 1, 1979

By C B. Valentin

It is acknowledged that the analysis of iron ores using X-ray fluorescence (XRF) for major and minor elements is best carried out on fusion discs. This method of sample preparation eliminates mineral and particle size effects which can lead to biased results when using pressed powder pellets. However, the fusion disc method is costly as it requires a high capital investment in platinumware, requires experienced operators and uses expensive fluxes. Also, the dilution effect complicates the analysis of trace elements. For many applications, such as exploration and mining control, the method of XRF analysis of iron ores by pressed powder pellet probably provides data of adequate quality. Kumba Iron Ore, an iron ore producer in South Africa, recognises this and carries out most analyses of iron ore by pressed powder pellet and uses the automated fusion method mainly for certification of in-house calibration standards and quality control (QC) samples that are used for validation of pressed powder pellet method purposes. Automated fusion is also used for analysing the composite export shipping samples. All the other exploration, production, despatching and plant operation samples are done by the pressed powder pellet method. Automation of sample preparation procedures should improve the quality of data for pressed powder pellets. To compare the precision of the three methods of sample preparation and XRF analysis, 20 aliquots of a QC standard were prepared and analysed by each procedure/preparation method. The results and statistical data on the most important elements, Fe, K2O and P, are as shown later in Table 2.Clearly the precision is best for the auto prepared fusion discs, as expected, and worst for the manually prepared pressed powder pellets. However, the data generated from the auto prepared pressed powder pellets compare remarkably well against those from the auto prepared fusion discs.

Jan 1, 2007

When Australian voters elected a Labor Government in March 1983 the value of the Jabiluka uranium deposit as an asset of Pancontinental Mining Limited effectively evaporated overnight. The day before the election, Jabiluka was Pancon's principal asset, with the Company's 65% stake in the deposit having a market value of the order of $US1 billion. This value had been set by an agreement reached with a potential customer, who was prepared to pay $US150 million for 10% of Jabiluka. The months before the election had been the culmination of ten years of unremitting effort to bring what was then the world's largest reserve of high'grade uranium ore into production. These efforts had included two and a half years of negotiations with the local aborigines, as well as exhaustive environmental studies and conceptual mine planning. All domestic approvals required to develop the Jabiluka deposit had been given to Pancontinental and marketing efforts had successfully placed about 50% of the expected uranium production with overseas utilities. It appeared that Jabiluka was about to emerge as one of the world's great mining enterprises. The election of a government with an anti-uranium policy stopped Jabiluka dead in its tracks. Pancontinental's largest asset had effectively become worthless and the Company appeared to be facing a bleak future.

Jan 1, 1987

By D F. Akhmetov, M Yasuike, M Komazaki, Y Kawa

Remote monitoring of geological situation at distant regions with complicated relief, including reliable detection of the rock falls and estimation of the scale of accidents, is of great importance for practical needs. In the paper, vibration data, caused by fall of sample objects and registered by cable sensors, are processed and analysed in order to construct some measure for the indirect evaluation of weight of fallen objects. Nonlinear models, which based on artificial neural networks (ANN), are proposed for the signal presentation. To improve and simplify the learning and classification abilities of the whole system, the aggregative learning method (ALM) is implemented. ALM features relatively low memory and computational resources needed for the procedure realisation, especially for data classification (recall) stage, in compare to conventional methods. The validity and efficiency of the proposed approach are tested through its application for rock fall detection and weight evaluation system using cable sensors and mobile communication network. Classification abilities of the proposed approach are shown useful for estimation of the fallen object weight. Characterised with high computational efficiency and simple decisionmaking procedure, the derived method can be useful for simple and reliable real-time monitoring system design.

Jan 1, 2003

By OÆBrien D, Priddle D

In order to avoid costly moisture penalties on coal shipments and to minimise rail freight costs, screen bowl centrifuges were selected and installed in the Mount Thorley Coal Preparation Plant for dewatering fine coal product. The Mount Thorley fine coal circuit consists of desliming the -0.5 mm (ww) fine coal in two stages of classifying cyclones prior to recovery by froth flotation. Provision has been made to bypass the flotation circuit with the classified flotation feed reporting directly to product and the centrifuge dewatering circuit has been designed to handle either flotation feed or flotation product. Major mechanical failures of the gearboxes and the ceramic tiling occurred early in the operation life of the machines which led to design changes being made to achieve satisfactory operation. This paper discusses the operating experience at Mount Thorley with respect to both mechanical and metallurgical performance of the screen bowl centrifuges since their installation in 1985.

Jan 1, 1989

By A D. Campbell, G R. Power

The objective of the draw strategy in a caving mine is to maximise economic return by minimising waste dilution3 and maximising ore recovery4. The draw strategy must also include suitable controls for air blast and mud rush hazards and is highly constrained until continuous cave propagation has been achieved. This paper details a three-year project at the Ernest Henry Mine (EHM), which used cave flow simulation software to develop a draw strategy that increased the mine value by 32 per cent.Dilution and ore loss can be significant in sublevel cave (SLC) operations and result in poor recovery and considerable economic losses. To minimise dilution and ore loss, cellular automata software was used to simulate cave flow over the mine life. The optimisation project required mining footprints for various cut-off grades to be developed. Draw strategies for each mine footprint were then generated using a range of shut-off grades. Economic assessment of each scenario was then conducted to determine the mine footprint and corresponding draw strategy that generated the highest NPV (net present value). The iterative simulation process was improved by developing automated software functions in the flow modelling software to reduce time taken to generate and assess life-of-mine (LOM) draw strategy scenarios.In addition to improving the NPV of the mine, the optimisation project also enabled a decrease in the mine cut-off grade which increased the ore reserve and extended the mine life. Overall, an iterative process of mine planning, cave simulation, economic evaluation and geotechnical analysis was used to significantly increase the economic return of the SLC whilst ensuring caving risks were controlled to an acceptable level.CITATION:Campbell, A D and Power, G R, 2016. Increasing net present value by a third at an operating sublevel cave mine using draw strategy optimisation, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 167–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

Major changes occurred in the management of loss prevention and risk management at operations in North and South America due to increased insurance premiums following the Olympic Dam fire in Australia in 2001. There are many different scenarios on how fires can develop and the estimated maximum losses (EML) those fires can incur. The EML is utilised by insurance companies to determine the cost of insurance premiums. The cost of insurance can be controlled at existing and newly designed solvent extraction (SX) plants by using risk reduction methods and design criteria to limit the fire exposure. A review of data collected during several loss prevention risk assessments can show how a budget can be protected from dramatically increased premiums and see which design of SX plant and fire protection standards best apply to your operations. The paper will investigate the pitfalls of existing materials of construction, capacity, geography, management practices, fire risk minimisation, and fire suppression systems. Intelligent engineering and managerial improvements implemented by the operations in the Americas in the past two years have further minimised the fire potential and benefited companies in insurance renewal negotiations.

Jan 1, 2003

By Herbst JA

During the last decade, it has been established that conventional mineral-processing control strategies based on classical control theory result in significant increases in plant throughput and operating-cost saving. The proper education and training of personnel using dynamic simulators of the principal unit operations is vital for proper design and maintenance of control systems. Severe multivariable interactions and numerous constraints on both manipulated and state variables in grinding/classifica-tion and flotation systems can be studied using time domain analysis with proper dynamic simulators. Two interactive programs are described, and the basis of each simulator and its structure are discussed. Two examples concerned with choosing, tuning, and decoupl-ing of manipulated and controlled variables for a grinding/classification circuit (DYNA-MILL II) and for a rougher flotation circuit (DYNAFLOAT II) are presented. The way in which these dynamic simulators can be used for the design of model-based control strate-gies is also outlined. A brief description of the use of these dynamic simulators for screening alternative strategies and circuit optimization is given.

Jan 1, 1985

By G Lind

Bridging of production stopes in narrow vein gold deposits contributes to significant financial losses and production delays. Bridging is caused when underbreak in the stope production blast occurs, resulting in less than the designed stope blast volume breaking out during blasting. Jundee Operations in the Northern Goldfields of Western Australia extracts ore from its expansive narrow vein orebodies utilising longhole open stoping. In 2006 it experienced bridging in ten panels, or 8.77 per cent of all panels, as well as multiple bridging in 30 per cent of these bridged panels. The Jundee orebodies are west dipping with the bridged panels dipping between 44¦ and 62¦. This paper examines some solutions from the drill and blast design perspective to minimise bridging occurrences. It was found that the then current drill patterns and number of holes were adequate from a longhole stope design perspective. However, changes to the blasting design, specifically modifications to the blast delay initiation sequencing, primer positioning and blasthole dump combined with timely stope surveying and back analysis, were implemented with the aim of preventing bridging in this narrow vein operation.

Jan 1, 2008