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The Mount Morgan massive sulphide body occurs in a volcanic sequence of Lower or Middle. Devonian age, which is subdivided in the mine into "Upper mine porphyries", "Banded mine sequence", and "Lower mine porphyries". This sequence is intruded by latite, Mount Morgan Tonalite (360 million years), and late Permian dykes. Distribution of macroscopic ore textures and minerals in the orebody are discussed and evidence is presented indicating the pre-Tonalite, Devonian age of the orebody.

Jan 1, 1974

By H R. Watli, K L. Davies, J A. Johnson

Novel microbial isolates that readily oxidise iron and sulfur were recovered from samples collected from a spent chalcopyrite/pyrite test heap. Methods were developed to enrich and isolate microbes that thrive in low pH environments and utilise iron and/or sulfur as sources of energy. Screening of these isolates revealed diverse substrate utilization (sulfur, ferrous ion, chalcopyrite, pyrite, glucose) as well as growth at temperatures between 30 - 50¦C. When native isolates were employed, shake flask leaching tests of chalcopyrite concentrate resulted in higher copper yields in comparison to laboratory reference strains Acidithiobacillus ferrooxidans (DSM 583) and Sulfobacillus thermosulfidooxidans (DSM 9293). After 700 hours several native isolates had leached between 20 - 30 per cent more copper than laboratory reference strains during experiments conducted at 45¦C. This research has established a unique culture collection of mining microbes that readily adapt to Australian conditions. Exploitation of these microbes may result in improved leaching kinetics and copper recovery from Australian chalcopyrite ores as demonstrated from shake flask leaching tests. Whilst this research provides a capability for Australian mineral sulfide ores, this technology can be easily adapted to suit ores of any origin resulting in more effective and efficient microbial leaching.

Jan 1, 2004

According to the temporal and spatial distribution of regional metallogenesis, the Pacific Rim can be divided into four global metallogenetic systems. The Asia-Australia W-Sn metallogenetic belt is the typical representative of intracontinen- tal metallogenetic systems. This belt resulted from Mesozoic and partly pre-Mesozoic tectonic magmatism, mainly re- lated to S-type granite of crustal source, that was generated by collisional orogeny combined with oceanic subduction in intracontinental and continental margin settings. Based on the concept of metallogenetic series, there is a group of min- eralised ore types showing a definite spatial and temporal distribution from endogenetic to exogenetic. These metalloge- netic series are widely distributed in the Asia-Australia W-Sn metallogenetic belt, and are well developed in Southeast China. Five metallogenetic series and two petro-minerogenesis evolution models have been established according to their tectonic settings, various types of granitoids and metallogenetic evolution.

Jan 1, 1995

The geology and mineral deposits of the West Pilbara Goldfield are described and comparison is made with the Pilbara Goldfield,, In the West Pilbai'a Goldfield two adjacent environments are represented by a predominantly clastic succession and a predominantly volcanic succession. These two successions are lateral equivalents and lithologically they are similar to the classical successions at Warrdiwdbna and Mosquito Creek. How- ever, no evidence of a significant erosional break has been found. It is suggested that the Archaean rocks of: the Pilbara Block represent a single geosynclinal cycle, which culminated in orogenesis, within which-local disconformities have been developed in various places: and that the sub-Mosquito; Creek unconformity at Eastern Creek may be the most widespread of these disconformities, Widespread evidence of'preconsolidation movement, aid the intrusion of igneous rock into. unconsolidated sediment, suggest that tectonism and igneous activity began at a very early stage, This was localised along lines of fracture in an unidentified basement.,.Moveme.nt was primarily vertical and persisted into the older Proterozoic, The sediments were enriched in metal by vulcanicity, chemical sedimentation, and possibly detrit`1' contribution. Diagenesis and metamorphism caused the remobòliyation of the metallic constituents of igneous and sedimentary, rocks which were then localised-in loci of dislocation-formed both before and after consolidation.,.. . . , . .

Jan 1, 1964

IntroductionOre BodiesRio GrandeBlack RockLeadCopperBlack StarLeadCopperStoping Methods and DesignFactors Affecting Ventilation PracticeTemperatures and Climatic ConditionsGeothermic GntdlentLegal RequirementsMine CasesMain Ventilation SystemMajor Fans and ShaftsVentilation CircuitsMan and Supply Shaft; No. 2 Ore Shaft; Urquhart ShaftMan and Supply Shaft; Davidson Shaft; No. 46ShaftLawlor Shaft; Urquhart ShaftControl of VentilationSummary of Upcasts and DowncastsAuxiliary VentilationType of Fans used, Vent Pipe, etcVentilation and Temperature SurveysDust SurveysInstruments Used

Jan 1, 1953

By W J. Shaw

Geometallurgical modelling is now a hot topic in deposit evaluation and in optimising mine performance; however, its history is long and varied. Historically metallurgical sampling has frequently suffered from a lack of data due to the cost of producing representative bulk samples. In the early 1990s geometallurgical modelling similarly suffered from a lack of data due to complex, time consuming and expensive sampling techniques. More recently, simple and relatively cheap tests for geometallurgical variables such as hardness, grindability, throughput, SAG power index, bond work index, crushing index, mineral recovery and concentrate grade have become widespread. The cheaper sampling has resulted in relatively large geometallurgical databases. However, most of the geometallurgical variables sampled are implicitly (and incorrectly) assumed to be additive when modelled by traditional geostatistical techniques, often leading to ill-informed and costly decisions. Geometallurgical variables are mostly non-additive so the current geostatistical challenge is to develop new approaches to dealing with this type of data. This paper briefly describes a historical case study of geometallurgical modelling of the George Fisher Pb-Zn mine completed in the mid 1990s, then outlines some of the current misconceptions of geometallurgical data and modelling techniques regularly applied to it, and finally discusses some recent developments in geometallurgical modelling, with examples from a number of current clients indicating the direction forward.

Jan 1, 2009

The Mt Leyshon Gold Mine is located 30 kilometres south of Charters Towers in Northern Queensland. The current open cut mine has been in operation since 1986. In 1992 a feasibility study was completed that recommended an increase in production to over 240 000 ounces of gold per year. This proposal required an upgrade of the processing plant to five million tonnes per year, and an enlarged mining fleet to provide additional ore, and to meet the increased waste removal requirements. The implementation of the mine expansion program during 1993 required the Life of Mine plan to be extensively revised. This required the assessment and management of potential risks associated with the mine design. The updated geological model using the 1992 drilling results along with the actual contract mining and processing costs were used to establish a series of nested optimised pit shells. The total and incremental quantities and costs were then analysed to determine a suitable pit perimeter. The pit and phase plans were then created and used to devise a staged development plan. The block layout plans for each bench were then established from which a detailed life of mine production schedule was created.

Jan 1, 1994

In the past two decades the global metalliferous mineral industry has trended away from pyrometallurgical (pyromet) and towards hydrometallurgical (hydromet) technologies including biometallurgical (biomet) processes. Pyromet, biomet and hydromet technologies have all developed considerably over this period. New projects have been biased or directed by legislation towards supposedly cleaner and greener hydromet and biomet technologies. The environmental cost and energy cost of pyromet production processes for copper and cobalt are compared with comparable hydromet processes using Life Cycle Assessment (LCA). The æreal costÆ of the global warming obsession and negative public perception of pyrometallurgy include greater carbon dioxide emissions and energy consumption per unit, associated with current hydromet technologies. Specific examples for copper and cobalt produced via the different routes are provided. The poor science involved with the global warming hypothesis is discussed. The use of LCA with sensitivity analysis as a decision making tool for mineral processing projects and technology developers is discussed.

Jan 1, 2004

Conditional simulation is a branch of geo- statistics which allows the simulation of a mineral deposit so that predictions can be made about the variability of some particular parameter of the deposit. A summary of the general principles, advantages and limitations of conditional simulation is presented together with an example based on coal seam thickness.

Jan 1, 1981

By Sorokin M, Komkov A, Fyodorov A

The Vanyukov Process is a high-intensity smelting system that has been proven over the last 20 years for various metallurgical operations including the smelting of copper, nickel, copper-zinc, antimony concentrates, municipal waste treatment and pig-iron production. Extensive pilot plant tests on copper and copper-nickel concentrates have provided information for the design of the commercial furnaces. The thermodynamic analysis, design idea and the data obtained from commercial furnaces have shown that Vanyukov Process would be the best choice to smelt copper-nickel and nickel sulphide concentrates as well as oxide nickel ores.

Jan 1, 1996

By T QUINLAN

A resource estimate uses data obtained by sampling an orebody. An example is described in which a random drilling pattern did not provide a representative set of assays, and the estimated resource was significantly less than the mine production. It is believed that a better estimate would have been made if the exploration holes had been drilled on a regular grid.

Jan 1, 1992

An empirical kinetic model is discussed that enables the number of stages in a carbon-in-pulp plant and the amount of carbon in each stage to be calculated for any desired metallurgical performance. It is shown that a knowledge of the kinetics of gold extraction by activated carbon in each stage assists plant operators in the important' areas of process control and optimization. Factors such as mixing efficiency, concentration and distribution of carbon through the plant, bypassing of pulp through a stage, and carbon poisoning are examined. The resin-in-pulp process for the extraction of gold cyanide is also discussed, and the chemistry of absorption and elution on strong- and weak-base resins is examined. In addition, operating results from a small-scale resin-in-pulp pilot plant are presented, and various applications in which resin-in-pulp may be preferable to carbon-in-pulp are discussed.

Jan 1, 1982

While, in the past, a great deal of attention has been focussed on technical issues and the performance of explosives in rock, the explosive user, an essential link in the chain, has often been neglected. In the mining industry, too often, the benefits of excellent technical work have been degraded over time due to the lack of definitive and documented control. Using the principles of quality management a quality training system was developed and implemented for management of explosives use at Gunpowder Copper Ltd (GCL). This paper describes the structure of the system, its development and implementation, and contains practical advice and information for managers responsible for blasting and charge crews. The paper is in four parts: I Quality systems. A brief overview of the relevant aspects of total quality management that apply to explosives use. The requirements for documentation, management and auditing are explored. 2. Training for competency. The five essential elements of Competency Board Training (CBT) are examined, including auditing. 3. The Gunpowder Copper system. Implementation of the complete training system. Documentation and its control, auditing, instructions for operators, management responsibility and means of obtaining operator ownership are amongst the issues raised. Reporting requirements are the means to effectively manage change are described. 4. Summary. The paper concludes with the tangible benefits seen by Gunpowder Copper through the adoption of a quality training System.

Jan 1, 1995

This opportunity to present a few thoughts on the question of professional education and training comes at a most appropriate time. In Britain, a great deal of energy is being expended in this, so-called, post-Finniston era, to create a new look for the status of engineers and engineering by the Engineering Council. Naturally, the tune and the tempo are being called by the big institutions which essentially serve the manufacturing industries. However, the Engineering Council in Great Britain also includes the mining and processing institutions such as the Institution of Mining and Metallurgy (IMM) and so there is a chance - if it is taken - for us to contribute to the debate and the determinations that emanate from it. The IMM, of course, caters for the professional status of those engaged in the mining and minerals industries and includes many who do not see themselves as engineers. Nevertheless, the debate is important to these other groups whose livelihood is inextricably bound up with those who are engineers and there are many facets of the engineering policies being shaped that will, I am sure, eventually be enshrined in the requirements for professional status across all the various disciplines in our industry.

Jan 1, 1986

By H. J. Glass, A J. Cornah

Improving the quality of the variogram helps to improve subsequent estimation and simulation processes. Two strategies for conditioning data prior to construction of the variogram are investigated using data from the Luce iron ore deposit in Canada. One strategy is the classic approach in which the deposit is subdivided into a set of structural domains. The domains are analysed individually and datapairs are recombined to produce a variogram. The second strategy is reconstruction of the deposit at an earlier stage of its history through unfolding. This involves transformation of the Cartesian coordinates into stratigraphic coordinate system. Improvement in the variogram quality, expressed in a decreased weighted deviation from a fitted model, is observed for both types of data conditioning. This indicates that, for the Luce deposit, application of data conditioning could also help to inform the selection of sampling locations.

Jan 1, 2006

By Purvis A. H, Greenwood-Smith R, Sowerby B. D

A nuclear technique for the determination of copper and nickel in bulk samples and drill core has been developed at Lucas Heights andfield-tested at Mount Isa. The technique, which is highly specific to the element being measured, utilises the gamma-ray resonance scallering process.A bulk mineral analyser was installed in mid-1976 for the routine assay of copper in bulk samples and drill cores, and remained in operation until late 1981. The operation of the analyser over this five-year period is reviewed with particular emphasis on reliability, accuracy and principal usage.The main application of this analyser was in stope planning and design whereby several thousand drill-core and Wall-chip samples were analysed. It was also used as an aid to underground grade control of stopes where ore dilution by supporting barren backfill was a problem.

Jan 1, 1984

A new gold cyanidation assay technique has been proven for a range of ores, where it has demonstrated benefits of being: ò Accurate (reduces the typical range of assay scatter almost three-fold, and avoids common fire assay interferences). ò Fast (under one hour, providing a quantum shift in space requirement and equipment utilisation each bottle roll can provide over 15 determinations per day). ò Simple (suitable for field application, no high skill or experience requirements). ò Profitable (reduced drilling, drilling time, ore misclassification and/or double handling after mining). ò Cheap (far lower cost than Fire or Aqua Regia Assays, ie LeachWELLTM costs around 10ó for a 20 g sample at 50 per cent solids, proportionately greater for larger samples eg $1 for 200 g samples which address most nugget effect problems). ò Relevant (distinguishes economic. ie cyanide-extractable gold, the only unequivocal value to use for true resource definition, mine planning and grade control). ò Robust (rough bucket chemistry of samplers does not seriously affect results). A new development is the provision of LeachWELLTM CAS, a solution, which also contains optimum cyanide and stabiliser concentrations; and offers greater: ò Safety (the dilute cyanide solutions are stabilised to avoid generating toxic HCN vapours; and present no cyanide dust or flying chips to deal with). ò Ease (a single squirt dispenses precise quantities of the entire reagent suite, avoiding multiple weighings). ò Reduction in total reagent costs. An inter-laboratory comparison on nine ore types, using two assay techniques (Fire Assay and Aqua Regia) involving 45 laboratories, has demonstrated that LeachWELLTM 60X assays for the samples tested, were equally or more reliable than typical Fire or Aqua Regia Assays. There is particularly great benefit in applying LeachWELLTM 60X assays to richer ores in comparison to Aqua Regia assays, which appear to be prone to very significant underassaying depending on individual analyst skills, and which often suffer greater nugget effects. The major impacts for heap leaching are that: ò Using the LeachWELLTM assay technique for grade control, ore of marginal grade is not accidentally discarded to waste or visa versa due to the scatter of assay data inherent in typical small charge (25 g) fire assays. ò LeachWELLTM assays very importantly report only that gold which will be recoverable in the heap, viz that which is liberated - an important factor where the coarse crush often leaves ten per cent of gold unliberated. These impacts are of particular importance for many ores (ie most of those recovered from open pit operations and at the margins of rich ore subject to slurry processing) subjected to heap leaching as the oxide zones often present major problems of nugget effects as well as mineralisation that cannot be accurately assigned through interpretation of clear structural controls.

Jan 1, 1994

By T Davis

The 500 orebody in the upper levels of Mt Isa Mines in north-west Queensland was mined by sublevel caving and block caving from 1962 to 1969. The hot and reactive rock mass of this orebody provided significant mining challenges including ground temperatures above those resulting from the geothermal gradient. Recently Xstrata Copper has been studying the potential to mine this orebody by modern caving techniques. Part of the study process has included re-accessing the ore zones for diamond drilling and trial development. A cross-cut trial drive, the first primary development into the orebody in more than 30 years, encountered a temperature increase in development holes from low sixties to almost 80¦C in less than 10 m advance. The issues associated with managing this risk include sourcing suitable quantities of reactive ground explosives for a single small heading and the temperature limitations of the explosives and detonators. Risk management outcomes included controls to mitigate the safety and reliability risks relating to misfires. The control that dealt directly with the challenge of continuing development in elevated temperature ground was to cool the holes before and during charging. The most effective and practical cooling medium proved to be water. Rapid rock temperature recharge time meant cooling had to continue as close to firing as possible. Reticulation systems were constructed to allow cooling to take place up until withdrawal for firing. No misfires occurred with the cooling system and additional controls in place. This proved that developing safely and effectively in the elevated ground temperatures of the 500 orebody is practicable.

Jan 1, 2008

In recent years a large amount of work has been done at various plants overseas, and also at Broken Hill Associated Smelters, Port Pirie, South Australia, on the use of Dwight Lloyd sintering plant gases for sulphuric acid manufacture by the contact process.Several plants have modified their sintering machines and operating procedure, and some have adopted gas recirculation techniques, to obtain a relatively high proportion of the sintering plant gas at an S02 concentration acceptable to a contact acid plant 1.These adaptations were investigated at Port Pirie, and it was found that gases of suitable S02 concentration could be obtained. The results justified installation of a contact acid plant and a decision was accordingly made in 1949 to construct such a plant.However, the local conditions presented some difficulties not generally encountered at other plants, the chief differences being:a. For maintenance of production of 98% H2S04 , an unusually high S02 concentration is required, because of the prevailing high temperature 'of the purification train cooling water.b. The entire sintering operation is conducted on two large machines, 55ft. x 10ft., operating in series as "First" and "Second over" machines (a two-pass roast.) Any interruption" to either machine causes a complete interruption of plant operation and gas flow.

Jan 1, 1951

By Darby H. P, Vincent R. J

Sydney's Eastern Suburbs Railway from Central to Bondi Junction required the construc- tion of 10.4 km of single-track tunnel and five underground stations. Much of this work took place beneath the commercial centre of Australia's largest city. This paper discusses the general precautions taken and the specific design solutions made for such problems as support of a 15-storey building with foundations several metres above the excavation to ensure negligible differential settlement, excavation immediately below running tunnels, underpinning of multi-storey buildings, tunnelling under massive masonry retaining walls and demolition and rebuilding of part-completed structures.

Jan 1, 1981