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By Clifford C. E

The Black Star and Racecourse orebodies below 15 level contain a major portion of the primary silver-lead-zinc ore reserves of 56 million tonnes at 150 g/t Ag, 6.4% Pb and 6.5% Zn at Isa Mine. Extraction from this area is scheduled to begin in the early 1980's. Mining in this block will be quite com- plicated as the ore is contained in a dozen separate orebodies varying in width from 3 m to 20 m with only narrow barren pillars between them in some cases. Mining objectives which consider metal recovery, costs, environmental and safety factors, operating requirements and rock mechanics are used to compare proposals. The planning work involved in formulating mining proposals considers disposition of reserves, scheduling factors, sequence of extraction, extraction methods, haulage set-up and ventilation requirements.

Jan 1, 1979

By Pak DL

Over the last decade computers have become an essential element in assessing the economic feasibility of mining new mineral deposits and in assisting a variety of related support functions. A broad overview is given of the many technical application areas where computers are contributing to the mining industry with reference to work being done on the evaluation of drill hole information, mineral inventory modelling, ore reserve estimation, financial analysis, process simulation, process control, workshop job scheduling, PERT applications, and com- puter aided drafting. In all these areas the computer has greatly reduced the manual effort involved in looking at alternatives. It has had a significant effect in eliminating delays in revising calculations, or rescheduling activities to incorporate new data or cater for changing conditions, while at the same time providing more accurate and prompt information for the management decision making Process.

Jan 1, 1980

By Moritz P

Thiourea has been recognised for a long time as an acid-stable complexant for gold. Generally, the use of thiourea has been shown to exhibit enhanced leaching kinetics compared to cyanide but suffers the disadvantage of excessive reagent consumption. Thiourea leaching is particularly com- patible with the extraction of gold from refractory ores. This is due to the need for an oxidative pretreatment to liberate the gold. Such pretreatments typically result in the production of an acidic residue. The application of novel thiourea leaching technologies to the extraction of gold from a bioleached pyrite concentrate was investigated. The interac- tion of leach variables with thiourea consumption and gold extraction was established. An economic assessment of thiourea leaching was compared with conventional cyanidation. The results indicated that gold leaching of the bioleached residue using thiourea compared very favourably with cyanidation.

Jan 1, 1991

By G Corder

The aim of the circular economy is to accelerate the transition from a conventional linear take-make-dispose economic model to a circular model. It is restorative and regenerative by design and aims to keep products, components and materials at their highest utility and value at all times. This extended abstract presents a brief overview of the circular economy, provides application of the circular economy in other industrial sectors including the downstream metals value chain and proposes how circular economy thinking could progress the development of complex orebodies.CITATION: Corder, G, 2018. Can the concept of the circular economy help unlock complex orebodies?, in Proceedings Complex Orebodies Conference 2018, pp 8–10 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

In late 1984, Council of the Australasian Institute of Mining and Metallurgy accepted a proposal to establish a Mineral Heritage Committee. This was to be involved in matters relating to mineral heritage-its recording, its preservation, and the acknowledgement that it can be of use to the mineral industry in the future. The Committee was established to ensure that all of the disciplines of our profession were included and that, so far as possible, all of our country as well as those countries of the Southwest Pacific Basin were represented. Some work has been commenced to bring real- isation of the importance of the heritage of our mineral industry to the forefront of the commu- nity's interest. There is not a state in this country and the Southwest Pacific where the mineral industry has not at various times proved to be the basis of community development.

Jan 1, 1987

Completing its historical role the opera tion of copper blast furnace of the Saganoseki Smelter was terminated in 1970, but it left some interesting data on metal lumps formed at the furnace bottom. Analysis disclosed the lumps to be speiss containing 100 to 10,000 g/t of Au and Ag and stratified to iron speiss and copper speiss. Solidifying temperatures of iron speiss and copper speiss being approximately 1,090¦C and 800¦C respectively, copper speiss precipitated at the lower side. The distribution coefficient of Au and Ag between matte and speiss (g/t Au(Ag) in matte / g/t Au(Ag) in speiss) is in the range of 1 x 10 2 to 2 x 10 ' and 1 x 10 1 to 5 respectively. The higher Cu % is in speiss, the-more An and Ag are distributed into speiss. Except for a few data, these results comfotm well to the range of distribution equilibria of Au and Ag in matte and speiss systems by Gerlach and Others.

Jan 1, 1980

By Barro L

Very large reserves of gas are contained in coal. Because of the low permeability of the coal gas flow rates are very low. Fracturing of the coal can be achieved by use of the nitrogen - foam frac techniques described but the flow rates after fracturing are not sufficient to support economic development. Fracturing of the seams in the Bowen Basin was as predicted but in the Sydney Basin no trace of the fracture could be found when development proceeded past the fractured well. Testing of coal samples has provided some insight into parameters affecting desorption Rates.

Jan 1, 1982

By Biswas AK, Hayes P

During the reduction of iron oxide pellets in the blast furnace it has been found that catastrophic swelling (up to 300% volume increase) can occur. Although the burden preparation conditions can be designed to avoid this phenomenon the exact reason and mechanism of the swelling has yet to be clearly identified. Swelling of the burden is undesirable since it reduces the interparticulate voidage in the blast furnace thus reducing gas flow through the stack resulting in low production rates of iron. The present study differs significantly from previous experiments in that reduction is carried out on single crystals of wustite thus the problems of control of gas composition and specimen preparation are minimised. The microstructures formed on reduction have been examined by optical and scanning microscopy. Pure wustite and wustite doped with various levels of CaO have been examined after reduction in controlled CO-CO 2 gas mixtures at 968¦C. The catastrophic swelling on reduction coincides with the formation of an unusually open iron structure in which the iron appears as whiskers or needles as previously reported. The spacing and thickness of the needles are shown to vary with impurity content and gas composition. Metallographic examination has shown in addition, however, that the whiskers do not necessarily constitute the only product form of the iron produced and in CaO containing wustites with less than - 2% CaO there is a transition from needle growth to porous growth of iron. Thus the % swelling of the oxide particles is dependent on the initial size of the oxide grains. Samples of FeO - 10% CaO exhibited a previously unreported product inorphology associated with the nucleation of 2CaO.Fe203.

Jan 1, 1980

A simulation model of the load and haul process where the loader cycle has been subdivided into its individual components is used to consider the benefits derived from improved drill and blast methods. Field data from a Hunter Valley mine is u

Jan 1, 1998

There is no other effective way for study ing firedamp and coaldust explosions than to produce controlled explosions in a pre-monitor- ed environment - either mine openings kept for the purpose, or special surface galleries. Such explosion testing facilities have been employed historically at Buxton in U.K., with lesser known installations at Bruceton, U.S.A., Tremonia, West Germany, Katowice-Mikolow, Poland and elsewhere. Both firedamp and coal dust explosions are studied. Normally coal dust explosions are initiated by somewhat standardised methane air mixtures, by explosives, or purely by coal dust. Various structures and suppression installations are installed in roadways and galleries prior to explosion to simulate destruction and suppression, and the results of such tests form the basis of suppression installations, especially stone dust barriers and water barriers. Other data collected from these experiments include rev- ersals of explosion waves, pressures and temperatures and duration of explosion waves, analyses of aftergases etc. Other uses of explosion testing galleries include testing of explosives, electrical equipment and frictional . sparking.

Jan 1, 1981

By Hayes J. A

The satisfactory ventilation of an extensive coal mine is a subject which requires continual attention from all concerned.It must be remembered that a colliery contains many miles of workings, extending in all directions and throughout which noxious gases may be given off either naturally or by oxidation of the coal; fumes from explosives will be produced, dust will be gathered and carried in suspension, and water will be evaporated, producing a high humidity. Hence a considerable quantity of air in movement must be available to provide sufficient oxygen for men and horses, as well as to dilute and sweep away impurities, and maintain a tolerable degree of coolness.To maintain these conditions a modern colliery is divided up from the main ventilation shafts or adits (as the case may be) into a system of main airways, and in the working districts is further subdivided into district splits. To initiate the air movement, large centrifugal fans with a displacement capacity of up to 400,000 cu. ft. of air per minute are installed, generally in drifts off the upcast shaft, or adit, and at the return end of the ventilating circuit. These fans are thus exhausting fans and by producing a region of low density bring the heavier air at the other extremity of the circuit into movement to correct the difference in density, so far as it is not prevented by the frictional resistance of the airways. A flow of air is thus established, and it is obvious that to enable this volume of air to be as great as possible, the frictional resistance of the mine airways should be maintained at the lowest practicable figure. To this end, main airways should be as large as possible, have sides as smooth as practicable, and be straight, any necessary bends being of large radius.REQUIREMENTS OF THE VENTILATION SYSTEMThe New South Wales Coal Mines Regulation Act contains stringent provisions on requirements of the ventilation system. The main points are expressed in the following extracts:"In every mine which is in operation, unless a certificate of exemption from compliance with this rule has been granted by the Minister, whether any person employed therein shall be...

Jan 1, 1947

By Lloyd C. J

The uranium markets are at present well covered by available producers. However the predicted increase in demand, recently reinforc- ed by the Arab oil crisis, will by, the early 1980s'outdistance supply. Current trends are towards light water reactors with-fast breeder reactors not expected to make any significant impact to the mid 1980s. The proposed lifting of the US embargo on the use of foreign uranium in US reactors will expand the market available to non US producers. A balancing in supply and demand worldwide will probably occur in the early 1980s. Australia's potential producers at present hold about 20 percent of the worlds U308 resources. Three companies, have contracts to supply nearly 10 900 tonnes of U308 between now and 1986 which represents about 1 percent of the predicted demand to 1986. Australian producers need to establish themselves more firmly in the market place in order that other countries will not replace us. Contracts can be written now which will allow for world market prices to be paid in the future, thus protecting the Australian producer.

Jan 1, 1974

By Kadoya H, Kondo Y

The Harima works were established in 1964 and started operation in 1966. The initial capacity was 3500 t/month of zinc and 1500 t/month of lead. Until 1990 a lot of improvements had been made and the capacity had increased 6600 t/month of zinc and 2200 t/month of lead without enlarging the furnace size. During the ten weeks campaign shut-down at the end of 1990, many modifications were carried out including the enlargement of the furnace shaft area. By these changes, the capacity has gone up to 7500 t/month of zinc and 2500 t/month of lead. In the sinter plant, the amount of SO2 rich gas supplied to the acid plant was raised to 50 000 Nm3/h from 43 500 Nm3/h. An electrostatic precipitator was adopted instead of a venturi scrubber to clean the rich gas. Oxygen enrichment has been continuously operated since August 1991, because the furnace capacity is more than the rate of sinter production. Utilisation of the sinter plant is high being as much as 97 per cent and the sulphur burning rate has been increased. In 1990 the furnace was replaced except the hearth. The shaft area was enlarged to 19.4 m2 from 15.3 m2. The target blast was designed to be more than 36 000 Nm3/h. Tuyere layout was changed to prevent slag breakouts. Due to these modifications shaft condition has been very good. Automatic launder jacket cleaners were installed to increase the lead cooling efficiency. Many other improvements and developments were also made. Coke powder injection from the tuyeres has been successfully operated since April 1987.

Jan 1, 1993

By G M. Jeffress, D C. Arne

There are two discrete aspects to collecting portable X-ray fluorescence (pXRF) data to obtain reliable results and to comply with reporting requirements under the 2012 edition of the JORC Code (JORC, 2012) – sampling method and quality assurance. A robust sampling program is required to obtain representative material for analysis. The appropriate method should be established for a particular project using a small orientation study. A variety of approaches to sampling soils, drill cuttings, rock faces and diamond drill core are discussed. These include using multiple spot analyses, scanning using a single operating beam and the collection of cutting saw pulps. The operator must also be aware of the attenuating effects of analysing through sample bags of different material types for various elements as well as the limitations of current pXRF instruments in reporting reliable data for certain elements. The analysis of the samples must also be accompanied by a quality assurance program in order to generate data that are ‘fit for purpose’. This includes recording X-ray tube resolution on a routine basis, using matrix-appropriate standards for which total elemental concentrations are available, using silica blanks, capturing sufficient duplicate analyses to constrain data precision and obtaining check assays to calibrate pXRF data against laboratory data. Examples of quality control approaches and data are presented. Table 1 of the 2012 JORC Code also recommends that information on instrument make and model, reading times and calibration be provided in any reporting of pXRF data. To this should be added information on operating mode and temperature, software version and moisture content of the samples. A robust sampling methodology with a suitable quality assurance/quality control program should produce pXRF data of sufficient quality for public reporting purposes, provided that the data are presented using appropriate cautionary language and adequate supporting information.CITATION:Arne, D C and Jeffress, G M, 2014. Sampling and analysis for public reporting of portable x-ray fluorescence data under the 2012 edition of the JORC Code, in Proceedings Sampling 2014 , pp 57–64 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

By S Warden, T Neville, P Leckie

At its simplest, the classification and characterisation of an orebody is a matter of Where, What and When. Where and with what spatial resolution are measurements taken, What properties are measured, and When are the data acquired, processed, and delivered to create the most value. This paper delves into how existing and near-term advances in measurement technologies, field automation, and whole-system-digitisation are combining to open new routes for mine and exploration productivity improvement. Commencing when the initial exploration hole is dug, the advancement in deployment of survey technology—from expert-operated, to driller-operated, to driller-integrated—is used to demonstrate a template for adoption of higher technology measurements. We then introduce and discuss the multi-use measurement as offering outsized returns from a single measurement run, highlighting two new technologies that acquire rock strength while drilling and downhole assay data as examples. For rock strength, we highlight a novel approach to determining Uniaxial Compressive Strength (UCS) while drilling, its relationship to and advantages over Mechanical Specific Energy (MSE), and how it offers utility to multiple downstream processes. For downhole assay, we detail how a back-tophysics approach to Pulsed Fast and Thermal Neutron Activation (PFTNA) analysis offers significant advantages over other measurement methods and earlier implementations of PFTNA, generating a rich data set that can significantly extend and improve the information on which mining decisions are made. Finally, we discuss the possibilities enabled via optimising data delivery, collection, and curation— noting a fundamental limitation of historical systems and exploring the possibilities that will be unlocked by soon-to-market solutions that better enable Orebody Characterisation data to (virtually) move in space and time with rock material post-blasting. Ultimately, the value of optimising the Where, What, and When from point of measurement to the moment it generates maximum value will create greater life-of-asset production for a lower cost and energy input.

Sep 1, 2024

Almost all the countries of the south-west Pacific and the Australian states have recently completed or have commissioned mineral royalty reviews. The prime reasons for this widespread and consistent action is the desire of the governments of these entities to redress perceived effi- ciency and equity imbalances and to ensure that the revenue raising motive does not override the necessity to maintain mineral exploration and development incentives. Governments are tending to adopt royalty systems comprising a com- bination of base royalty and a profit component. Resource rent royalty and royalty holidays have been introduced and anomalies, such as royalty free gold production, still exist but appear to have uncertain futures. Tasmania ranks as the Australian state with the lowest aggregate royalty levy/production value ratio whilst Papua New Guinea has the highest royalty objective achievement level in the south-west Pacific region.

Jan 1, 1988

Byproduct coking is practised in three of the major Australian ironmaking centres, the Newcastle and Whyalla works of the Broken Hill Proprietary Co. Ltd. and the Port Kembla works of Australian Iron & Steel Pty. Ltd. Coking first commenced at Newcastle in 1915 and at Port Kembla in 1938. The installations established at these centres include coal cleaning facilities and com- plete byproduct streams. The Whyalla plant, because of its location is somewhat less extensive, having no coal cleaning plant and a comparatively restricted byproduct section. As new batteries have been built every opportunity has been taken to incorporate modern design features and improved operat- ing techniques. This has included the provision of equipment to reduce atmospheric and water pollution. A marked reduction of markets for byproducts has had serious repercussions on the profitability of this section of the Industry.

Jan 1, 1972

By Smith I. T

Mine operators have long recognised that the results achieved in primary blasting are critical to subsequent mining activities. With the introduction of "in the hole" drills under- ground and the advantages offered by the use of water gels in conjunction with ammonium nitrate-fuel oil (ANFO) explosives, new mining methods have been developed and enabled improvements in older methods. Pumpable water gels have been used with varying success underground. These gels allow a high loading density even in ragged bore- holes. The problems encountered with slumping in upholes is recognised so the current trend is to use these gels in downholes where wet holes are prevalent. Cartridged water gel technology has advanced to the point where it has allowed the replacement of nitroglycerin (NG) based explosives and pumpable water gels. Today, gels can be made as a tampable product for use in development headings or as a slump- ing product for downholes to give an effective coupling. With the introduction of the Tovex« pneumatic loaders, the problems associated with a pumpable gel were eliminated and gave the user the ability to alter his loading density.

Jan 1, 1977

By P Hatherly, A Melkumyan, D Wyman

Chemical species distributions in rock sequences can be modelled using Gaussian processes (GPs) to predict the weight percentage between known data points. This method can be improved by dividing the modelled area into regions of different mineralogy. In the context of many iron ore deposits, marker shales give the initial guidance of where these regions may lie. These shales give rise to distinctive peaks in the natural gamma downhole logs, which are conventionally identified by hand. A GP method has been developed to automate this task.Once the appropriate boundary has been located on the basis of shale occurrences, chemical assays from exploration drill holes are used to find the exact boundaries of interest. These boundaries divide the drill hole stratigraphy into regions of different mineralogy, each of which display their own distinct correlations between the main elements and oxides (Fe, SiO2 and Al2O3). Iron ore shows a negative correlation between Fe and Al2O3, but in banded iron formation (BIF) there is a positive correlation between these species. Similarly, SiO2 and Al2O3 have a positive correlation in the shales and ore but a negative correlation in the BIF. Correlations obtained within ore-, BIF- and shale-dominated regions are therefore better than those obtained using the entire log and can be used to improve the results obtained when modelling.

Sep 26, 2011

By Keele R. A

The Cambrian structure in the Mt Read Volcanics was produced by four deformational events: obduction of forearc-derived mafic/ultramalic complexes in the early Middle Cambrian, a middle Middle Cambrian extensional phase related to the post-collisional Mt Read volcanism and VHMS mineralisation, Middle Cambrian E-W folding, and Late Cambrian N-S folding and basin inversion. The major phase of VHMS mineralisation in western Tasmania is restricted to the very brief period of extensional tectonics within the middle Middle Cambrian. Within this period a N-S graben was produced with a complex series of transfer zones, largely striking E-W. Most VHMS mineralisation is restricted to the top of massive volcanic successions, with several mines close to Cambrian transfer structures. Many of the transfer structures continued to be active until the Devonian. The later compressional Cambrian events are not significant in localising orc formation. Within the Rosebery mine a complex pattern of minor Cambrian normal faults has a second order control on the distribution of the mineralisation.

Jan 1, 1997