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The Queensland Magnesia Project is based on a unique cryptocrystalline nodular magnesite orebody which required an innovative approach to process design in order to economically exploit the characteristics of the ore and produce a marketable range of high quality refractory magnesias for a declining world market. High quality natural refractory magnesia must have an MgO content in excess of 95 per cent with a very strictly controlled content and ratio of residual impurities such as calcium, silica and iron. The natural products compete with magnesias derived by chemical extraction from sea water or brines which exhibit very high purity but often lack other characteristics which are of value to refractory brick makers. Since start up in late-1991 QMAG has achieved a remarkable market penetration for both its deadburned and electrofused products with sales for the 1993/94 financial year representing 92 per cent of deadburned capacity and 138 per cent of original electrofused capacity respectively, all at a time when the world steel industry has been in recession.

Jan 1, 1995

The highland region of Papua-New Guinea is relatively rugged terrain where stream gradients are steep. In areas where porphyry copper deposits outcrop the streams commonly expose primary sulphide mineralization in unoxidized rocks. Stream sediment geochemistry combined with float examination and broad geological mapping proved to be an effective tool for detection of outcropping bodies of mineralization. After discovery, detailed stream sediment sampling, soil sampling and rock chip sampling, together with detailed geological mapping proved adequate to delineate drilling targets. Reconnaissance stream sediment sample density was dictated by geology and access and a density of one sample per 25 Km2, or less, was desirable to ensure a high degree of confidence in the programme. Research indicated that the base metals occur in sulphide form in stream sediment and that the -80 mesh size fraction gave the most reliable results. The evaluation of results from any one area relied on the interpretation of the local geology. Basic histogram methods for determining background and threshold values for metals in stream sediments were

Jan 1, 1973

By Corrans I. J

A wide variety of copper-bearing gold ores exist throughout the world which have yet to be processed economically for gold recovery. The copper minerals present in these ores can be many and varied and usually result in high cyanide consumptions and problematical levels of copper in leach solutions. The copper content is often assessed as being of nuisance value as the ores are generally of the grade or type which can support neither a copper project nor a straight gold project, due to the interference of copper. Many of these problematical gold-copper ores could possibly be processed economically for gold recovery using a novel ammoniacal cyanide leaching system which utilises a copper-ammonia-cyanide complex as an effective lixiviant for gold, yet limits copper dissolution and conserves cyanide. Results from recent testing have promoted a re-evaluation of the economics of treating some gold-copper ores. This paper describes the novel leaching process and discusses the conditions employed to treat a variety of gold-copper ores.

Jan 1, 1992

By J J. Frausto, G R. Ballantyne, M S. Powell, R Cruz, K Runge

Hydrocyclones are the most widely used device for classification in a grinding circuit. However, even the most efficient hydrocyclone has a bypass of fines from the feed to the underflow which reduces comminution circuit performance, as well as misclassification around the cut point. Fine screens classify only according to the particle size, allowing for a reduction in the recirculation of fines back to the mill. The development of high capacity multi-screens makes fine classification in a grinding circuit a viable option. Minera Saucito recently substituted hydrocyclones with screens in its grinding circuit. The change of classifier resulted in an increase in throughput and lead recovery but a decrease in silver recovery. This case study presents the changes in comminution and flotation performance that occurred after the installation of screens and uses historical operational data collected over 12 months of operation to investigate the reasons for these observed changes. CITATION:Frausto, J J, Ballantyne, G R, Runge, K, Powell, M S and Cruz, R, 2017., in Proceedings MetPlant 2017, pp 298–314 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

Reconciliation of the ore reserve has been an integral part of mine planning since Bougainville Copper Ltd. commenced mining operations at Panguna in 1972. Confidence in the ore reserve is considered essential, both for long term planning of the deposit, and for fair and accurate reporting of the mining resource to shareholders. Recoverable, proven reserves are published annually. Although the ore reserve quoted is based only on diamond drill hole (DDH) information on a 122 metre by 122 metre grid, predictions are regularly reviewed against production. Concentrator results are taken to be the best estimate of grade and tonnage. Surveyed mined perimeters and average blasthole grades are reconciled at the end of each month against the concentrator figures. Predictions of the in-pit reserve are made using an orebody model. DDH and blasthole (BH) sample grades are used to make predictions for both long and short term planning. This paper describes how reconciliations are used to validate ore reserves at Panguna. Development of the orebody model is described, and some of the difficulties encountered in doing reconciliations are addressed.

Jan 1, 1987

Direct measurements of liquid contents in foams obtained from (x-terpineol a-T) n-pentanol (AmOH) and n-octanol (OctOH) solutions were carried out using a column of special construction. The column enables to determine the liquid contents by cutting-off foam layers of various thicknesses and measuring amounts of liquid contained in the cut-off foam layers. Liquid contents in the whole foam layers, in the top foam layers of thickness 14 ¦ 1 mm and distribution of water alongside foam height were determined. The average liquid contents were high and reached a level of 30, 35 and 40 per cent for foams formed from cc-T, AmOH and OctOH solutions, respectively. The liquid contents in the top foam layers were much smaller. They were of an order of five per cent for a-T and AmOH and 12 per cent for OctOH. On the basis of the liquid distribution alongside foam height some practical conclusions concerning possibilities of minimising amounts of liquid contained in the collected concentrate are presented.

Jan 1, 1993

Blasting is known to be both an important and an easily quantified cost factor in rock breaking operations. However, the indirect costs and benefits of the blasting operation are not easily determined due to the irreversibility of the mechanisms involved and the multiplicity of influencing factors. A general conceptual model showing the relationship between blasting and mining costs is well known, but serious attempts to address the critical real relationships have all floundered on the fact that not enough is yet known about either detonation physics or blasting effects. This can only be remedied to the extent that blasting instrumentation enables researchers to pin down not only the relationship between the detonation process and its impact on a particular environment, but also the downhill costs of handling the rock, repairing any damage and building in "Safety Factors" to provide for imponderables. It is vital to standaraize on specifications for instrumentation and measurement techniques and there is a need to review what has been achieved in blasting expertise so as to focus on the most fruitful paths for future work.

Jan 1, 1990

It is now 32 years since Walsh's classic publication (1) heralded the beginning of atomic absorption spectrophotometry (AA) as we know it today. During this time, AA has developed into the most widely used analytical techniques for the determination of the metallic elements. The years have seen progressive changes in instrumentation so that today it is a highly sophisticated technique. One area of development in AA that is experiencing renewed attention is in the area of electrothermal excitation. In this technique a flame is not used by the analyte solution is atomised by an electrically heated graphite furnace. For a large number of elements the graphite furnace atomic absorption spectrophotometer (GFAA) is considerably more sensitive than flame work. It is common to be able to detect concentrations one hundred times smaller than those possible by flame. Today's geochemists are finding that they can gain valuable information out of very low limits of detection. Electrothermal atomic absorption spectrophotometry (or GFAA) allows for low limits of detection and can be seen to be a valuable aid to geochemical prospecting Analysis.

Jan 1, 1987

By Tyson G. R

A novel system has been developed using computer imaging techniques to make on-line measurements of material on a moving conveyor. Meas- urements of the mass or volume of conveyor materials are important in large open pit mining operations such as those operated by the State Elec- tricity Commission of Victoria (SECV). Such on-line measurements can be used for monitoring and controlling the production and transport of coal or overburden, and to assist in maintaining production levels. This paper describes a conveyor burden volume measurement system which is currently under development at the Research and Development Department of the SECV and although targeted initially for use in the Commission's open cut mines, the system is suitable for use on any open conveyor system. A basic developmental system has been built to demon- strate the viability of the technique used and further work on the system is planned. The measurement technique and the major components which have been developed as part of the system are described, some comparisons are drawn with other existing measurement systems and potential errors and future development are discussed.

Jan 1, 1989

The South Mine, property of Broken Hill South Limited, is situated at Broken Hill, NSW, Australia, towards the southern end of the main lode. The leases (MLs 7 and 8) cover a length of 2400 feet along the lode outcrop and the workings extend, at this date, to a depth of 1940 feet below the collar of the original main shaft and to 825 feet below sea level. Mining operations have been continuous for about 58 years and during this period nearly 12.5 million tons of ore have been mined. The monthly tonnage extracted approximates 30 000 tons in normal times.The ore is a mixed sulphide containing galena and marmatite; the gangue minerals are principally calcite, rhodonite, quartz and garnet. A typical assay for a monthly period is 14.4 per cent Ph, 5.6 ozs Ag, and 11.6 per cent Zn. The whole of the ore is concentrated on the property by combined gravity and flotation methods. The lead and zinc concentrates produced are railed to other centres for the extraction of the contained metals.

Jan 1, 1994

By Kukla G. T

A Seam deposit User oriented Mine Planning System (SUMPS) was developed by The Broken Hill Proprietary Company Limited (BHP) at its head office in Melbourne. It is one of the computer mine planning systems developed by the Corporate Data Processing (CDP) section of BHP. To date it has been employed in the feasibility study of four coal prospects for the BHP Group, including Gregory in central Queensland - Ham and Van Hoorn (1978). It was also used in detailed short term mine planning for Gregory. A recent application was in the feasibility study of Saxonvale, a multi seam coal deposit in New South Wales with seams up to 20 m thick. The other two applications of SUMPS were also on thick multi seam coal deposits. Development of programs for the underground sub-section of SUMPS is continuing. SUMPS was developed and implemented on mini computers with graphics and plotting peripherals. The company's philosophy towards computing is one of centralized development and project planning, with transfer of hardware and software to site once the mine becomes Operational.

Jan 1, 1980

The Hishikari gold deposit, discovered by the Metal Mining Agency of Japan, has become a giant class epithermal gold deposit with the highest grade of gold yet recorded in the world through detailed exploration and development by the Sumitomo Metal Mining Co., Ltd. The exploration strategy involved a regional approach combining geological and gravity surveys over a 900 km2 area which had historically produced over 120 t of gold. These surveys were carried out to grasp the common geologic features of epithermal gold deposits in the survey area. A genetic model for epithermal gold deposits in the area under regional survey was also considered based on detailed research of the Kushikino epithermal gold deposit which was in operation at that time. This model was applied to the targeted areas, and important relationships between mineralization, host lithology, intensive propylitic alteration and gravity highs became apparent. The Hishikari block was selected in this way and bonanza gold was discovered during drilling. Since the development of the Hishikari mine, information useful for further exploration for the same type of deposit has been accumulated.

Jan 1, 1995

By Barro L

There is currently a world wide interest in coal-oil technology as the search continues for alternative energy sources to reduce the consumption of petroleum crude. An important aspect of this coal-oil technology study is to obtain information on the flow properties of coal-oil slurries. While some work has been reported on the flow behaviour of black coal-oil suspensions, very little work on brown coal-oil suspensions has been reported. In this paper flow charac- teristics of brown coal-oil suspensions for various coal concentration and temperatures have been presented. A Capillary rheometer, designed to handle settling suspension, has been used for deter- mining rheological properties. Brown coal of 0 0725 mm average particle diameter has been used in this work. The oil was a coal derived product having a boiling point range of 234¦- 319¦C, Apparent viscosity of all suspensions was found to increase on storage due to ageing. Ageing might have occurred due to physico- chemical interactions between coal and oil. Flow behaviour of some suspensions changed from Newtonian to non-Newtonian on storage.

Jan 1, 1980

By J Manuel, R Muddle

The demand for iron ore has increased significantly in recent years, with new iron ore sources being mined to meet this demand. As the composition of sinter blends changes with the availability and cost of iron ore, so too does interest in the impact of new ore types on granulation and ultimately productivity. This paper describes a study into granulating characteristics of seven iron ore types, including various hematite and goethite ores. The effect of ore type on feed moisture requirements, green bed permeability, green bed strength and granule size distribution was examined for single ore blends containing coke, flux and returns. The ore size distribution was varied in these blends and its effect on granulating characteristics examined. It was found that the optimum moisture requirement of the ore was more dependent on ore type than ore size distribution, but ore size distribution (and specifically intermediate particle loading) had a greater effect on green bed permeability. The saturation moisture value for an ore was found useful in predicting both optimum granulation moisture and green bed permeability.

Jan 1, 2005

The products from beneficiation present themselves at opposite ends of the spectrum, and yet numerous synergies exist in the preparation of coking coal and hematite iron ore products for their common export markets. Returning to the coal side of the business with Anglo Coal following a five-year sojourn in WA with Hamersley Iron, has provided the opportunity for comparing and contrasting some of the key synergies of the supply chains of both bulk commodities.Comparisons include consideration of things like: resource evaluation (especially quality aspects), run-of-mine handling and preparation, beneficiation, product handling and transportation, quality assurance and customer awareness, value-in-use and impacts on iron and steelmaking, and supply chain environmental aspects.Inherent within these are several other notable contrasts including: æseamsÆ and æorebodiesÆ, rocks and minerals, rejects and tailings, oxidation and weathering, suppliers and users, and marketing and purchasing, to name but a few.This paper covers some of the more interesting of these synergies and raises some potential opportunities for sharing knowledge and innovation between the two areas of activity in the future.

Jan 1, 2005

By Browne TJ

On 13 October 1993, a shallow earthquake registering 7.1 on the Richter Scale occurred near Tauta in the Finisterre Range of Papua New Guinea (PNG) killing 37 people. The aftershock series lasted three months and resulted in considerable landslide damage that destroyed villages, food gardens and airstrips, and blocked rivers causing catastrophic flooding. These effects have irrevocably altered the form of many of the valleys and rivers draining into the Markham and Ramu valleys.The earthquake occurred in a pilot study area for a landslide hazard mapping project being carried out by the PNG Geological Survey that commen-ced in April 1993. Comparisons made between areas identified as unstable during the study with those damaged by the earthquakes show good correlation.It is concluded that aerial photograph and Landsat TM imagery interpretation can be used with a high degree of confidence to identify potential landslide hazards in mount-ainous terrain. Landslide hazard maps are promoted as a tool for use in the route planning of roads and powerline corridors, as well as for identifying vulnerable communities.

Jan 1, 1994

By Gillies A. D S, Just G. D

Coal washability data can be used for assessing coal quality. However, the techniques of using these data to solve quality problems differ from one mine to another and certain problems may never really be investigated due to limitations of the available techniques. One promising way to overcome these limitations is by correct application of geostatistics.A geostatistical study on coal washability data was undertaken based on a data set of closely spaced in-pit bore cores. These bore cores were analysed consistently over a relatively simple geological area. The average distance between the drill holes was about lOOm. There were 78 drill holes available for the area after deleting the erroneous bore cores. During the study, nine extra closely spaced drill holes were drilled within a single mining block.A procedure to construct two coal quality models, a kriging or cokriging model and a simulation model, was proposed. The modelling results for the data above are discussed and results of a mine scheduling exercise based on the models developed are included.

Jan 1, 1992

By Kobayashi M

Particulate chalcopyrite samples (78 ~ 98 mole per cent chalcopyrite, screen size fraction from 710 to 250 µm) were prepared by crushing and sieving lump ore samples from 12 locations in the Mt Isa Mine. Measurements of thennoelectric power (which does not involve the passage of a current) were made using a packed bed that was compressed by loading with a weight and placed in a temperature gradienL Details of the apparatus are described.The effect of particle size was investigated by preparing 12 fractions, with mean particle sizes ranging from 605 to 2.2 µm, from one of the ore samples. Values of thennoelectric power decreased with both increasing particle size and loading pressure; however it remained fairly constant for particle sizes above 80 µm, when loading pressure exceeded 3.3 MPa.Measurements of the chalcopyrite samples gave an average value of -260 JlV/K (-248 ~ -268 µV/K) for nine samples and about -290 µV/K for three samples, showing that these samples were all n-type semi-eonductors.

Jan 1, 1990

By Hendon G. W, Carr F, Jiang Y

A vast majority of the operating longwall sections use shield-type face supports to provide ground control in the United States. As a co-operative research program between the University of Alabama (UA) and Jim Walter Resources, Inc.(JWR), a joint research program is underway to study interaction of shields with surrounding rock masses. A series of analyses on the response of shields are performed using monitored data at a longwall face in a deep coal mine. In this paper, various effects of parameters, such as leg pressure, setting load, developing load, maximum loading rate, pressure in capsule, and convergence between canopy and base, are discussed and recommended as stability indices. A microcomputer program is being developed for instantaneous interpretation of the shield monitored data, and for giving warnings of potential problems. The preliminary results define the effects of the setting load, developing load, and rate of developing load or leg closure rate. The objective of the study is to understand the shield characteristics and their interaction with surrounding strata in real time, then develop a reliable program for maintaining longwall stability.

Jan 1, 1992

Mr. President, Ladies and Gentlemen, it gives me great pleasure to welcome you, on behalf of the Council and Administration, to this University and extend to you our very best wishes for a most successful and stimulating symposium. We as a College of the University of N.S.W. were always proud of the excellent support we received from your Institute members and the close association that existed between our organisations. Now we have matured into the University of Wollongong and have to stand on our own feet, we will need all the support we can get from such bodies as yours to ensure that we are not only producing graduates but are also playing a vital role in the community. Although there is no planning for a school of Mining Engineering in the near future, we do look forward to this being a viable proposition eventually and we will then be able to offer to your Institute wider facilities for your activities and ones which will embrace both the Mining and Metallurgy phases. Thank you Mr. President.

Jan 1, 1975