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The radiolarian biostratigraphy of the western part of the Gympie Province, north of Brisbane, has been examined. This part of the province comprises mainly the Amamoor beds and the Gympie Group, which have been assigned Permian ages on the basis of localised marine macrofossils. This study has shown that the Amamoor beds and the Gympie Group include older strata than previously supposed.The Amamoor beds consist of at least two tectonic units, namely a melange unit (unit A) and a well stratified sequence of sedimentary rocks (unit B). The former unit, regarded as an accretionary subduction complex, contains chert blocks ranging from Late Devonian to Earliest Carboniferous, while the latter unit yields Permian radiolarians. Latest Devonian to Earliest Carboniferous bedded cherts occur in sequence previously mapped as Amamoor beds and Gympie Group.

Jan 1, 1990

The amount of land subjected to coal surface mining in the United States has been reported at 1, 302, 000 acres (1). Latest National Coal Association estimates (1968) show that about 65, 000 acres are affected annually in the production of 186, 000, 000 tons of coal. Peabody Coal Company affects approximately 9500 acres annually in the ten States in which we are presently operating. Surface mining at Moura, Australia was begun in February 1961. In Marcy 1963, the Marion 7900 dragline with 35 cubic yard bucket went into operation and in 1967 the Marion 8900 dragline with a bucket capacity of 130 cubic yards was put into operation. In addition a third dragline, a 480W was added in 1969. It carries a 15 cubic yard bucket and is used to work areas that are too small to justify movement of the larger machines, In 1969 the Moura surface mine produced 3, 002, 774 short tons, and in 1970 3, 418, 933 short tons.

Jan 1, 1971

Scheduling mine development and underground construction has been the bane of most mine managersÆ lives at one time or another. Even though scheduling software has developed significantly over the last 20 years, mining projects continue to take far longer than expected to complete. It would appear that possession of a gleaming 1000 activity bar chart generated by the latest project management software and plotted in multiple colours offers no guarantee at all that any of those 1000 activities will be completed on time, let alone the project as a whole. The author has earned his æmasters in disastersÆ with more than one project running over time and budget. This paper describes some of his experiences in scheduling major mine development and construction projects and the lessons he has learnt along the way. In particular, the paper examines a range of key issues that mine schedulers must take into account when planning mining projects. The paper also examines the development of scheduling software and particular advance rates used in scheduling mine development projects in Australia.

Jan 1, 2000

By Lott JB, Scuffham JB

Until very recently the application of solvent extraction to. the recovery of metals has been considered only for ithose operations where no other process was available. In general, .these operations, have involved metals such as 'f uranium or the rare earths, where the value of metal recovered has been very high. As a result, the tendency has been to consider solvent extraction as a very specialised, high cost technique with minimal application in the base metal industry. Since the mid-1960's this attitude has had to be changed drastically with the development of solvents specifically designed for the selective extraction of individual metals such.ascopper. The result is that solvent extraction must now be regarded as a proven hydrometallurgical technique for the recovery of base metals, and in particular copper. The first significant event in the application of solvent extraction to base metals was the production by General M. Inc. of a compound, designated LIX-63 (R)(1), which was a specific extractant for copper from ammoniacal sns. This did not find a wide application, however, because copper solutions with a pH in the applicable range we more readily treated by conventional techniques.

Jan 1, 1970

By A Weeks an, R Bertinshaw, S Khosrowshahi

Good mining is central to any approach to value tracking. Good mining occurs where the ore is correctly delineated, measured and fed to the mill. This process is usually referred to as grade control, ore control or quality control. There are now ways to measure the efficiency of this process, such as by using conditional simulation, and a brief synopsis is presented. Resource estimation is the foundation of ore reserve estimation, which should enable useful prediction of the expected metal to be recovered from mining and milling. Significant improvements have resulted from applying new techniques such as the Chain of Mining (CoM) method, which models the mining process. Again, a brief synopsis is presented. Tracking value from the mine through the mill implies a linear sequence of processes that can be modelled. Reality is more complex and there are error components, feedback loops and breaks in the Chain of Value. Modelling the total production process in a number of operations is considered, including the various impacts on producing reconciliations. Procedures are also discussed for handling a number of difficult issues such as: different data supports, stockpiling strategies, blending from multiple ore sources, blast movement and underground ore extraction.

Jan 1, 2002

By O Pasca, B Hogg

Consistent slag blow end point detection remains one of the challenges in the Peirce-Smith converters at Mount Isa MinesÆ Copper Smelter. Under blowing results in foaming on copper blow and carry forward of oxide skims to the anode furnace. Over blowing results in high copper losses to the slag. Both present safety issues and contribute to lower copper production. The end points of the slag making phases are assessed by inspection of a bar sample. A bar sample is a thin accretion layer that adheres to a steel bar when it is inserted into the tuyere while the converter is blowing. This method is biased and subjective, so there is heavy reliance on operator experience. The Semtech Optical Process Control (OPC) system was installed in early 2002 for converter slag blow end point detection. Initial plant trials did not improve all aspects of converter operations, and uptake by operators was poor, so the system was not used. In early 2005, the Semtech OPC system was re-visited and another short trial was conducted to evaluate the permanent use of the system for slag and copper blow end point detection. During this trial, the Semtech OPC method was found to be superior to bar sampling for slag blow end point detection. The implementation and refurbishment of the Semtech OPC system has resulted in plant improvements and given a better insight into converter operation during blowing. Oxide skim generation carried forward to the anode furnace has been shown to decrease with increasing compliance with Semtech OPC. Some of the expected improvements to converter operation were not found to be significant. Semtech OPC is now well received and utilised by converter operators. Individual paper available only. Not included in book or CD ROM Proceedings.

Jan 1, 2005

By G Brewster

The Eagle on the Hill tunnels form part of an upgrade of Mt Barker Road, 15 km to the southeast of Adelaide. The upgrade significantly improves safety and reduces delays on this major road, which winds steeply through mountainous terrain. The twin tunnels each spanning 15 metres run in parallel for a length of 480 metres. The tunnels are excavated in slightly weathered high strength slates and very high strength quartzites of the Saddleworth Formation on the western margin of the Mount Lofty Ranges. Steeply dipping slate cleavages and the high fracture ratio result in many slope stability problems in the project area. The level of geotechnical investigation undertaken prior to the calling of tenders for the project was extensive. This included the excavation of a pilot tunnel along one of the tunnel alignments, which allowed accurate mapping and rating of the rock, resulting in an increased level of confidence during the tender process. One of the features of the winning alternative tender design was the use of canopy tubes, flexible steel ribs and shotcrete to replace up to 40 metres of deep portal cuts in unstable rock with driven tunnels. Slope stability issues were overcome with the use of rock dowels and shotcrete. The support concept allowed the safe driving of the tunnel portals with as little as two metres of overburden. The design incorporated lining drainage and criteria for fireproofing based on European experience to ensure the ability of the tunnels to remain stable in the case of a severe fire incident. The support design allowed for maximum flexibility with a range of support types able to deal with the varying ground conditions. Design development and support refinement continued throughout the tunnel construction phase with close liaison between the designer and the constructor. Monitoring and review of feedback from the construction site by the Sydney based design team was easily achieved by means of electronic transfer of photographic and survey information, telephone and fax communication and regular site visits. The contractor for this project is Macmahon Concrete Constructions Joint Venture (MCCJV) and the designer is Connell Wagner. Excavation commenced in January 1998 with tunnel breakthrough having been achieved in early-August 1998 and mid-September 1998 respectively. Concrete lining construction is scheduled for completion in April 1999.

Jan 1, 1999

It is a very great pleasure indeed to participate in this interesting and important seminar. My two visits to Australia in the past have been extremely pleasant and this one is equally so. My task is to tell you what has been happening in the United States, in these past few years especially, in regard to the management of our air resources and to present in some detail the difficulties we in the copper, lead and zinc smelting industries have been experiencing. The sudden upsurge in interest in air pollution in the United States is a strange phenomenon indeed - strange because we've had air pollution a long time, just as long as there have been large cities using fossil fuels for heating purposes. And the problem has been studied for quite a long time. As early as 1919 studies by the U. S. Bureau of Mines were done in Salt Lake City, where I .live. In the winter of that year extensive measurements were made of airborne particles - dust and smoke. The average concentration of particles found was 870 micrograms per cubic meter of air. A very large number compared to levels we find today. A microgram of course is a very small unit, one twenty-eight millionth of an ounce. A fine human hair two inches long weighs about 100 Micrograms.

Jan 1, 1971

By Grader F. E

A linear motor properly wound can serve as a mechanism for separating paramagnetic sulphide minerals, like pyrrhotite, from other sulphides and associated gangue minerals. The effective- ness of separation depends on the energising current of the separator, the frequency of the a.c. cycle, and the particle size of the minerals. The speed of travel of the minerals over the surface of the separator is also a function of particle size, and appears to be constant. The movement of pyrrhotite, magnetite and iron filings of comparable size fraction (150um +74pm) on the linear motor surface has been observed using a cine camera. An attempt has been made to give a theoretical basis for the movement of the particles by calculating the minimum electrical energy required to move them. Further, the rate of decay of magnetic moment of the particles has been estimated for magnetite and it has been found that sufficient residual magnetism existed in the particles after they had been exposed to the first half of an a.c. cycle for them to have like polarity with the second half of the cycle. The particles are therefore repelled from the motor surface every second half of the cycle. This repulsion due to remanent magnetism is the probable cause of particle movement over the linear meter surf, e.

Jan 1, 1980

By C R. Stanley, D Lawie

The measurement of error in assays collected as part of a mineral exploration program or mining operation, including errors introduced during sampling, sample preparation, or geochemical analysis, historically has been undertaken in a variety of ways. Different parameters have been used to describe the magnitude of relative error and each of these parameters is related to the standard measure of relative error, the coefficient of variation. Calculation of the coefficient of variation can be undertaken in a variety of ways; however, only one produces unbiased estimates of measurement error: the root mean square coefficient of variation calculated from the individual coefficients of variation. CITATION:Lawie, D and Stanley, C R, 2012. Average relative error in geochemical determinations - Clarification, calculation and a plea for consistency, in Proceedings Sampling 2012 , pp 181-184 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

Excavator output rates given in Makers' catalogues are sometimes based on favourable operating conditions. Mine operators and planners are more interested in the Effective Hourly Output in normal operation (Qe) a plant system can give hour by hour and year after year in a particular application. The number of hours mining plant will be available for normal operation will be less than the annual total of 8760 h. The number of the available hours which can be utilised at Qe will depend largely on the number and types of units in the plant system, the manners in which they are applied and the nature of the deposit in which they work. The emphasis herein is on continuous systems for deep stripping with BWE's as the primary excavator. Examples and suggestions are given for the annual hours at Qe for some BWE systems.

Jan 1, 1981

By A B. Richards

Time window analysis that limits the explosive mass fired within a specified time window (commonly eight milliseconds) has been used for many years in blast design by explosives engineers. Despite several warnings in the past that this technique has limited practical or scientific basis and, in many cases, does not effectively control vibration, almost every textbook and blasting manual refers to time window charge mass limits as a primary vibration control technique. It has become entrenched in some blast vibration management plans, despite being inappropriate for the particular situation. With the flexible initiation timing available with electronic detonation almost a practical reality, and the 8 ms constraints in-built into the signal tube initiation system thereby lifted, it is timely to review the significance of the 8 ms time window in controlling blast vibration. This paper re-visits the original research that led to the development of the 8 ms criteria and the non-supportive conclusion of the original researcher. Because airblast was not measured, the 8 ms time window was never intended to be applicable for airblast control. Examples of blast designs are given in this paper that comply with the 8 ms time window limit that result in substantially increased air and ground vibration, together with examples of blast design that does not satisfy time window considerations, which results in reduced air and ground vibration. Techniques that identify wavefront reinforcement, due to the combined effect of drilling pattern and delay sequence, can assist explosives engineers to avoid high blast vibration situations that result from the inappropriate application of time window techniques and other adverse delay combinations.

Jan 1, 2003

By B Bonfils, P Lois Morales, C Evans

One of the main challenges for current and future mining and processing methodologies is to understand the characteristics of the rock so that its behaviour in one or more parts of the mining process chain can be predicted. Features such as rock texture, mineralogy or border complexity between minerals control how the rock behaves from the processing plant through to the final products, including tailings disposal and thus can affect the feasibility of the project from technical, economic and environmental impact perspectives. Understanding how the mineralogy and texture of rock affect its behaviour in mineral processing is a demanding area of research and is essential knowledge in predicting the processability of complex ores in different stages. This study aims to demonstrate that different types of relevant information can be extracted from a range of currently available analytical methods. However, this information can be used in a complementary way for building a more comprehensive rock characterisation at the microscale and better-predicting ore processing characteristics from the intact rock through to tailing disposal. CITATION: Lois Morales, P, Evans, C and Bonfils, B, 2018. Multisource rock characterisation at microscale for a better understanding of processing characteristics, in Proceedings Complex Orebodies Conference 2018, pp 44–48 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By M Chen, W S. Ng, Y Liu

In the processing of refractory gold-bearing sulfides, pressure oxidation (POX) is commonly known for its role in liberating the gold in solid-solution via oxidation of the sulfide occlusions. For deposits that contain arsenic-bearing species including arsenian pyrite and arsenopyrite, POX serves an important secondary function in the fixation of arsenic, via the hydrothermal precipitation of stable arsenates such as scorodite and basic ferric arsenate sulfate (BFAS). There have been various investigations on the impact of different POX conditions on arsenic precipitation and the stability of the formed phases, but less is known about the changes to the arsenic carrier that occur in the curing stage, which follows directly from POX. The primary function of curing is to coax the dissolution of sulfates to reduce lime consumptions during cyanide leaching, and the slurry is kept at elevated temperatures near 100°C to achieve this. While the arsenic-bearing phases are expected to undergo transformation during this stage, there has thus far been limited experimental evidence. In this study, the effect of curing time and curing temperature on the arsenic-bearing species and arsenic deportment in the POX product has been investigated. Leaching of the curing products was also conducted to examine the stability of the arsenic species in the solid precipitates.

Aug 24, 2022

By Hare S. M, Lumsdaine I, O&apos

Converter slag assaying 3.7 per cent Cu is produced by Mount Isa copper smelter at a rate of up to 180 000 tonnes per annum.Priority is given to the processing of ore, however concentrator capacity periodically exceeds that of the mine and the opportunity is taken to treat converter slag. It is processed in batch campaigns, typically through the Copper Concentrator, but the Hilton Concentrator has also been used. Slag and ore are kept as separate as possible, since each has an adverse effect on the flotation performance of the other.

Jan 1, 1993

By K Haroon, J D. Speed, S P. Wood

Online analysis of continuous and batch processes has seen a dramatic increase in recent years, with examples ranging from petrochemicals to pharmaceuticals, to industrial biotechnology and food and drink. The particularly challenging environment of alumina processing has meant that instrumentation needs specific features and characteristics to be truly suitable, features such as: robustness, resistance to caustic conditions both in the analyte and the ambient environment, and reliability for long-term continuous use. Here we present the development of a novel FTIR spectrometer that achieves these requirements through the use of a static optics arrangement of mirrors, and stable diamond-tipped light-pipe probe. Firstly we give a very brief explanation of spectroscopic analysis, and the difference between FTIR and other infrared methodologies. Next we outline the novel arrangement of mirrors required to produce an interferogram without moving mirrors, and compare the benefits and drawbacks of this approach instead of conventional designs. We then share the results of laboratory analysis of synthetic Bayer liquors, with detection limits for aluminium hydroxide, sodium hydroxide, sodium carbonate and various sodium salts of organic acids. We then share the results of analysis on production samples, both in idealised laboratory conditions and then online in the process itself. Lastly we present work on in situ ultrasonic descaling solutions to avoid scale build-up and provide continuous cleaning of the probe – preventing the need for probe removal and manual cleaning.

Aug 24, 2022

Most publicity about the copper industry nowa- days is focused on the adequacy of ore reserves and on excessive mining capacity. These concerns, stemming from public awareness of actual and poten- tial shortages and oversupplies, relate to production rather than consumption. Perhaps the reason for this one-sided view is that copper is thought of as a commodity which is conspicuously traded in world markets, rather than as one of many industrial materials that serve today's rapidly changing tech- nology. Copper differs from other widely traded com- modities in that its real cost of production has pro- gressively increased since World War II. The reasons for the increase are identifiable by analyzing operations in one of the world's large producing centres, the copper province of Arizona. Another respect in which copper differs from some other com- modities is that increases in demand occur less auto- matically in the case of copper than they tend to in commodities whose consumption is more directly related to population growth. The copper industry's current inability to generate and attract needed investment capital is attributable to these differences between copper and other com- modities; it suggests that the concept of copper purely as a commodity is outdated. The key to the problem is better integration between the activities of copper producers and users. Depending on cir- cumstances, integration takes various forms- for example, investment tied to long-term sales con- tracts between producers in developing countries and consumers overseas; common ownership of pro- ducing and manufacturing facilities in industrialized

Jan 1, 1978

Atlas Copco is one of the worldÆs leading providers of industrial productivity solutions (Atlas Copco, 2009). Furthermore, the company spans 160 markets and held 34 000 employees at the end of 2008. The company is organised under three ætechniquesÆ whereby the Construction and Mining TechniqueÆs business division is located within +rebro, Sweden. This paper is aimed at briefly facilitating information on how the company and more specifically, the Construction and Mining Technique is run. Also, by sharing my experiences, this paper is intended to encourage and motivate students currently studying for a degree relevant to the minerals industry, to apply for this extremely beneficial scholarship. Through a number of presentations relating to the various divisions, products and aftermarket services of the company, I came to realise that Atlas Copco extends beyond simply selling equipment suitable for the mining and civil industries. This tour through Sweden also contained highlights of visiting the Underground Rock Excavation factory, Surface Drilling Equipment factory and Secoroc divisions. I was also fortunate enough to participate in a tour of the LKAB mine in Kiruna. In addition, time was allocated to less industry related activities, and I was able to go dog sledging, sip vodka cocktails out of ice glasses at the Ice Hotel and enjoy traditional Swedish foods of moose and reindeer. Most important and memorable to me; however, was the ability for employees of Atlas Copco to speak of the company and their products with such passion and enthusiasm, which truly made this a motivational and unforgettable experience.

Jan 1, 2009

By Winrove G. S, Herdie G. J, McCarthy C. A

Production of hot metal from the Hlsmelt Research and Development Facility at Kwinana, Western Australia commenced in October 1993. The stand-alone facility is a unique, coal-based, integrated ironworks equipped to process iron ore fines to pig iron and simultaneously undertake a wide range of research tasks. The data generated will be used to verify the commercial potential of the technology and to set the design and operating parameters for a full-scale production plant. The design, construction, commissioning and initial operation of the HRDF has required many innovative and practical solutions to be developed and implemented by the international group of organisations contributing to the Hlsmelt Project. Initial operation has produced results which demonstrate the potential of the unique process technology associated with the core plant smelting unit. The recent achievement of post-combustion levels of 60 per cent with heat transfer efficiencies greater than 85 per cent demonstrates that the performance obtained with the Small Scale Pilot Plant in Maxhutte, Germany can be reproduced at a larger scale. The results presented in this paper support the thrust for further intensification and future commercialisation of the process.

Jan 1, 1995

By S Phinn, V Glenn, P McKenna, P D. Erskine, D Doley

The key goals for mine site rehabilitation require mine managers to demonstrate that rehabilitation is safe, stable, self-sustainable and non-polluting. Within this context, it is reasonable for stakeholders to expect that mine site rehabilitation is resilient to disturbance impacts such as fire and drought. However, mine managers actively avoid fire on rehabilitation; and as a result have limited understanding of fire behaviour on revegetated landforms, the long term implications for site stability and the potential risk to site relinquishment. An experimental fire that was conducted at the Curragh Mine site in May 2015, burnt 117 ha of 19- to 21-year old mine site rehabilitation, mimicking wildfire conditions and creating a mosaic of fire impacts across the landform. Using a combination of ground surveys and remote sensing assessments, we demonstrate that over a two year period, ecological metrics such as species richness, woody density and understorey biomass all recover to pre-fire levels for both grassland and open woodland areas. This is supported by WorldView-3 satellite imagery and the remote sensing assessment using the differenced Normalised Differenced Vegetation Index (dNDVI) which shows high regrowth within the burn area in 12- and 24-month image captures. The results suggest that within the recorded conditions, this site is resilient to fire impacts, and has the capacity to recover to pre-fire levels within the first two years following the fire.CITATION:McKenna, P, Erskine, P D, Phinn, S, Glenn, V and Doley, D, 2018. Measuring the recovery of coal mine rehabilitation following fire in Queensland using remote sensing and ground surveys, in Proceedings Life-of-Mine 2018, pp 141–146 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018