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By Ritchie AS

The principles of chromatographic and electrophoretic separations are described in simple non-mathematical language. Brief details of the analytical procedures and of equipment are given. Partial analyses of rare earth elements in monazites from four localit- ies in New South Wales are compared with analyses from other localities. The presence of uranium in two of the monazites is recorded. The occurrence of rare earths in nature is outlined and its geological significance is indicated, A low capital cost method of analysis of rare earths in monazites is Introduced.

Jan 1, 1972

During the last two decades, restrictions on access to land for mineral exploration and development in Australia have intensified. State and Federal legislation relating to Aboriginal land rights, national parks, marine parks, wilderness areas and other conservation areas, the surface rights of farmers in New South Wales and Western Australia, national, State and world heritage, urban developments and acquisition of land by governments for other purposes have all placed limits on mineral exploration and mine development activity. More than 20% of Australia's land area is now either unavailable for mineral exploration or available only under severe constraints. Access to this land is denied at a significant economic cost to the Australian community. There have been few attempts to quantify this cost. More importantly these restrictions have developed on an ad hoc basis promoted by single interest government departments often with little regard for rational land use planning. The mining industry has embraced the community's conservation ethic and accepted that conservation areas should be set aside and that within those areas mineral activity should be restricted. In some cases the restrictions on exploration near areas of outstanding scientific, historical, archeological or scenic importance may amount to an effective prohibition. The industry has vigorously opposed the exclusion of mineral activity in conservation areas on purely emotive grounds, unsupported by scientific evidence and in disregard of land use potential, consideration of multiple use potential or consultation with existing or potential land users likely to be effected.

Jan 1, 1987

By Hedge AS

Mt Whaleback is one of the largest open-cut iron ore mines in the world. Haulage cost is the single largest component of operating costs at the mine. Past studies towards alternatives to truck haulage have recognised the potential viability of an in-pit crushing and conveying system, dependent on the proportion of uphill haulage. After seventeen years of mining Mt Whaleback still contains more than 1,000 million tonnes of ore, needing 1,800 million tonnes of waste removal to extract it. What was once a quarry has now turned into a large open pit. The increasing proportion of uphill haulage, the need to replace ageing 120 ton and 200 ton trucks and the necessity of achieving and maintaining a higher stripping ratio prompted, in 1984, the initiation of a new feasibility study into the viability of alternative material handling systems. A semi-mobile in-pit crushing and conveying system was found to be most suited to Mt Whaleback conditions. The East Pit was selected as the best location based on the analysis of haulage profiles measured on long term incremental mine plans. A capacity of 22 million tonnes per year was considered achievable by the proven technology currently available. A detailed estimation of capital and operating costs of two systems - one with trucks only and another with trucks, crusher and conveyor - for the removal of 22 million tonnes per year of waste rock, showed substantial cost savings achievable by the proposed system. An economic evaluation of the two systems established the advantages of constructing the in-pit crushing and conveying system. This is now under construction and will be commissioned in early 1987. Experience gained in constructing and operating this installation is expected to influence decisions on similar installations in future.

Jan 1, 1986

Determining the controls of high-grade mineralisation at Vera Nancy requires careful data collection and assessment on a global and specific deposit basis. The techniques developed over 60 years ago to analyse structure, grade and width data are just as applicable today and can be enhanced using modern geological modelling software. High ore grades at Vera Nancy are controlled by both the primary geometry of the mineralised structure and the intersections of the main mineralised veins with subordinate splay veins. The main mineralised structure dilated as a consequence of extensional tectonics while the splays acted as conduits bringing oxidising surficial fluids into mixing zones precipitating high gold grades. Near-mine exploration is focussed on identifying zones of vein flexure and splay interaction to locate the relatively small high-grade shoots. Data modelling in a 3D environment is an essential process for understanding the geometry of the system being explored.

Jan 1, 2000

By R C, K L. Rees, J S. J van Deventer

In contrast with previously published models for the carbon-in-pulp (CIP) process, the model proposed in this paper incorporates film transfer, intraparticle diffusion, simultaneous leaching, preg-robbing, the loading of multicomponent species, and the effects of fouling and changing cyanide levels. The rationale behind this comprehensive model is that changes in fouling and competitive adsorption along a CIP cascade affect the profiles of gold loading. As it is impossible to quantify all these non-ideal factors, a method is proposed whereby an imaginary species is postulated so as to combine all the competitive effects. A plant survey at the Telfer mine has shown that the mass loss due to a gravimetric analysis of the fouled carbon could be used directly to quantify this competitive effect. The degradation and consumption of cyanide along the Telfer CIP cascade enhance the loading of copper on to the carbon, which should be taken into account when modelling the gold profiles. It appeared that the effect of cyanide itself on the loading of gold was negligible compared with its effect on the copper. Evidently much more research is required on this topic in order to optimise CIP operations exposed to constantly changing conditions.

Jan 1, 1998

During a mineral exploration programme in an environmentally sensitive area near Mount Painter in South Australia, a helicopter was used to position, construct and service drilling rigs in order to avoid the need to create new access tracks. The drilling programme was designed to optimise the advantages of natural landforms in order to minimise the environmental impact of site construction and drilling activities. This minimisation of land disturbance reduced the required amount of rehabilitation measures to the extent where all impacts of the helicopter-supported programme had disappeared within twelve months of completion of work.

Jan 1, 1995

By F Pavloudakis

The installation of on-line analysis systems in the open-pit mines of the Public Power Corporation SA (PPC, the state-owned electricity entity of Greece) is considered to be the key-parameter for performing improved quality control and blending/homogenisation of the produced lignite. In order to investigate the accuracy of these systems under the site-specific conditions of the Greek lignite deposits, a research project was carried out. This was necessary since there is lack of experience in using on-line analysers in mines that produce a fuel of such a poor and largely fluctuating quality. After thorough market research, a dual energy gamma ray transmission on-line ash analyser was installed in Kardia mine of Ptolemais û Amynteon Lignite Centre, which is located in West Macedonia, Greece. The initial results obtained after the realisation of a series of dual-comparison trials (ie using two series of reference values that allow three-way comparisons) pointed out several problems that obstacle the achievement of high accuracy on-line measurements. More specifically, the measurements obtained by the analyser were higher than the concentrations determined by the two laboratories when the ash content was lower than 12 per cent (in wet basis). On the contrary, when the ash content was higher than 12 per cent, the measurements of the on-line analyser were lower than the concentrations determined by the laboratories. In other words, the range of the measurements obtained by the analyser was narrower than that corresponding to the lab analyses results. Therefore, the use of this on-line analysis system under the site-specific operating conditions of Kardia mine does not guarantee improved quality control of the lignite fed to the mine-mouth located power plant. Most probable reasons that explain the above-mentioned problems are the following: The frequent and widely ranging fluctuations of the chemical and mineralogical composition of the lignite transported by the conveyor belt, especially as far as its calcium content is concerned. This result from the nature and the origin of the mineral matter co-excavated with the lignite, which varies from calcareous marls to sands and clays rich in aluminium and silica minerals. The fluctuations of the lignite quantity transported by the conveyor belt. The change of the linear concentration of iron contained in the fabric of different belt parts.

Jan 1, 2003

By Van Deventer J S J

The first step in the design of a process to treat a possible economic precious metal deposit should be an examination of the mineralogy of the ore. Using this and other initial tests, the extractive metallurgist can design a process to treat the ore. In the field of precious metal metallurgy, little emphasis is placed on the mineralogical information available to the metallurgist. The information is of far more use to the geologist and the mining engineer. Diagnostic leaching was designed to open up the field of mineralogical analysis to the metallurgist. When a mineralogist looks at the deportment of gold in an ore, he is usually looking for an element which is present in parts per million, so that errors in sampling are multiplied dramatically. Diagnostic leaching offers a cheap, simple, practical alternative. In order to determine with which minerals the desired precious metal is associated, a specific mineral is first eliminated using a selective oxidative leach, and cyanidation is used to extract the precious metal (in this case gold and silver) liberated by the destruction of this mineral. The precious metal extracted can be measured in solution to give a fairly accurate record of the amount of the precious metal associated with that mineral. Furthermore, the residue from this first stage can be subjected to another selective acid leach, and the process repeated. The procedure can be varied to suit the mineralogy of the matrix material. At the end of this diagnostic leach the metallurgist is left with a complete record of the deportment of the precious metal. He can now use this information to design a metallurgical flowsheet to treat the ore. Diagnostic leaching is thus an analytical tool which can be used by the metallurgist not only to examine new ores, but also to look at problems occurring at existing plants. The procedure is not only limited to ores and residues but in fact can deal with any type of intermediary product that occurs on a plant. The information gained from analysing an intermediary product can give a useful indication of how well a unit process is working, eg flotation, roasting, etc.

Jan 1, 1992

By A R. A Gomes

The Metropolitan Rapid Transit Authority (MRTA) Initial System Project (ISP) - Underground Structures North, UGN, is the northern section of the blue line, which is the first stage of an underground mass transport rail system of 77 km to be implemented in the central area of Bangkok, Thailand. The UGN section (Huai Kwang - Bang Sue) consists of approximately 8 km of twin single track bored tunnels, nine underground stations and some short cut and cover tunnel sections. The paper focuses on the main issues involved in the structural design of the precast concrete lining, which is the definitive structural support of the bored tunnels. It includes an overview of the site and geotechnical conditions, specific properties of precast concrete linings, ground-structure modelling, approach for the assessment of load conditions and respective sectional forces and particulars of the detailing of the reinforcement and the segment testing program.

Jan 1, 1999

Since the mid-1970s there has been increasing attention in the South Pacific area to the problems of disaster planning and management at various levels, mainly from regional through national to provincial levels. This concern has been expressed in a variety of ways. International aid donors have made their views known in commentaries or reports. Seminar discussions have been organised at the regional level (such as at Suva, 1976; Suva, 1979; Tonga, 1982 and Suva, 1983). In-country training workshops or meetings have been organised (such as the "Disaster Preparedness Workshops for Non-governmental Organisations" in Pacific countries, jointly run by the Australian Red Cross and the Australian Overseas Disaster Response Organisation and supported by AIDAB, in Vanuatu, 1985; Solomon Islands, 1985; Western Samoa, 1986; Fiji, 1987; Tonga, 1987; Lae and Port Moresby, Papua New Guinea, 1988) or held outside the area (ACDC at Macedon, 1981). Training and/or research institutions have been established such as the East-West Center, Honolulu, and the Asian Disaster Preparedness Center, Bangkok (more Asia oriented). As part of the East-West Center Pacific Islands Development Program's Disaster Preparedness Project, a detailed manual of disaster preparedness and response procedures and guidelines has been published (Carter, 1984).Table 1 and figure 1 show that the area with which this discussion deals is a highly fragmented island region, comprising many small, some minute, nations, both in land area and population. The social structure is predominantly rural, with the capital city often making up a small part of the total population and, in absolute terms, little more than a small town. Outside the administrative and governmental activities concentrated in the capitals, in most cases the indigenous inhabitants depend on subsistence agriculture or on usually a monocultural concentration on a cash crop, most frequently coconuts.

Jan 1, 1990

By Frfas C, Parrilla F, Regife J. M

A project to develop the Zinclor electrowinning cell to industrial size is being conducted at Tecnicas Reunidas' Research and Development Centre with Spanish Ministry of Industry support. This project is the final development phase in zinc electrowinning from a chloride medium, the highest ZINCLOR technology development level prior to the industrial scale having already been reached. This paper covers the outcomes and conclusions corresponding to project Phases 1 and 2: Process Selection and Industrial Electrodes (1 m2) design and testing. The most important achievement reached is that there are presently available industrial cathodes and anodes for the Zinclor diaphragm cell giving an optimum response for zinc chloride electrowinning with unit power consumptions between 2.65 and 2.80 kWh/kg Zn, depending on the diaphragm type. Standard electrolysis conditions were: 65 g/L ZnC12, 3 g/L HCl, 160 g/L NaCl, 350 g/t Zn arabig gum as the addition agent, 36¦C, and 400 A/m2 current density. The selection of electrodes, diaphragms and organic additives for the industrial scale tests have been optimised. The complete electrowinning cell development, with electrodes having an active area of I m2, enables the evaluation of Zinclor Technology application for industrial processes.

Jan 1, 1993

By Quast K. B

The ore used in this test program was a composite sample from Waihi, New Zealand containing 2.7 g/t gold and 36 g/t silver. From the testwork it was found that a high concentration of sodium cyanide (0.1 per cent) was necessary to ensure a high recovery of both gold and silver. There appeared little chance for either differential leaching or adsorption of gold and silver. The addition of bentonite clay decreased the rates of gold and silver dissolution. The addition of 50 g/1 NaCI had little influence on the rate of silver extraction. The addition of 5 g/l carbon gave adsorptions of 70 per cent of the gold and 35 per cent of the silver, indicating the possible presence of base metal cyanides in solution. The addition of excess sodium sulphide only precipitated 70 per cent of the silver in solution, adding further evidence to the presence of base metal sulphides. The production of separate silver and gold products was not possible by either preferential leaching, preferential adsorption of gold on carbon or preferential precipitation of silver.

Jan 1, 1991

The St George orebodies are situated within the tectonically disrupted eastern limb of the Boogardie Syncline.Highly disturbed rafts of banded chert formations occur within a sequence of felsic volcanic tuffs. The chert forms the hostrock for the gold mineralization.The gold distribution within the irregular and narrow banded chert formations is erratic and patchy. The average gold content of the two orebodies is between 3 - 4 g/t Au.Economic mining of these relative small, irregular and low grade St. George orebodies can be carried out by using a highly selective mining method.The highly selective mining method uses an excavator as the principle mining tool. Blasting, breaking and loading of the rocks is done in a different way than by using a front-end loader as with the conventional mining method. Simple, and therefore cheaper, blasting breaks the rocks and lifts them up without major displacements.

Jan 1, 1984

By Ellyett C. D

This paper is an appraisal of the application of optical-mechanical-scanners operating in the non-photographic infrared wavelengths (3-5 and 8-14 micrometres) to mineral exploration in Australia. Pundamental principles of the operation of airborne scanners and their data output, thermal infrared (IR) imagery, are summarized. It is contended that thermal IR imagery often depicts the distribution of electromagnetic radiation emitted from earth surface materials better than aerial photographic techniques because optical-mechanical-scanners sample wavebands which straddle the wavelength peak of earth surface emission. To illustrate the geological features which such scanners can depict, reference is made to thermal IR imagery of a number of areas in Australia where the technique has been applied for exploration purposes. The images demonstrate that this technique can detect structural features like faults and folds, stratigraphic data by distinguishing different rock types and delineating their

Jan 1, 1973

By P Moser, P Schimek, F Ouchterlony

This paper summarises the findings of 27 model-scale bench blasts in magnetic mortar, which were conducted from 2011 to 2014 at the blasting site of the Montanuniversitaet Leoben.The aim of the study was the investigation of the influence of blasthole delay times in small-scale bench blasts on the face characteristics and cracking damage created in the surrounding rock, which affects the fragmentation in subsequent rows.The test specimens or blocks, which were produced out of magnetite concrete, were roughly 1:100 in scale to normal bench blasts. The confinement of the testing blocks at the sides and back ensured the similarity to normal bench blasts with regard to the wave transmission into the surrounding rock. The specimen contained three or four rows with five blastholes each and were shot row by row, with virgin (undamaged) material in row 1 and increasingly damaged or preconditioned material in the following rows.The tested delay times varied between 0, 28, 73 and 140 µs, which corresponds to 0, 0.4, 1.0 and 2.0 ms/m of burden.The evaluation of the material properties showed that the use of magnetite concrete eliminated the inhomogeneous behaviour of rock, but some unexpected differences of the individual production cycles were still detected.The characteristics of the bench after each blast was evaluated along three horizontal lines out of a 3D model of the bench face. The tested delay time sequences of the virgin (first row) and single preconditioned blasts (second row) produced more overbreak for longer delays, while the third-row shots resulted in a smoothened surface independent of the chosen delay.The introduced damage after every blast was evaluated by an observation of irregularities on the newly blasted bench face. The visible cracks at the top of the testing blocks were documented and divided into several crack families according to their angle, length and origin. The remaining block was broken out of the blasting site after blasting, cut into several horizontal and vertical slices and dye penetrant spray was used to visualise the cracks created. Some of the detected crack families showed an influence of the delay time. The calculated mean crack density and mean crack intersection density showed that longer delays resulted in a higher degree of damage.The fragmentation results were well reproduced by the basic three-parameter Swebrec function. The observed improvement of fragmentation in the second- and third-row blasts was linked to the preconditioning of the burden for the following row while blasting the actual row. With the exception of the simultaneously initiated blastholes, the blasts showed coarser fragmentation for the shortest delays, while the longest delays generated the finest fragmentation.CITATION:Schimek, P, Ouchterlony, F and Moser, P, 2015. Influence of blasthole delay times on fragmentation as well as characteristics of and blast damage behind a remaining bench face through model-scale blasting, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 257–266 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Thomas E. G

In the economic evaluation of any Australian mining project, changes in taxation can significantly affect viability. Australian tax laws, particularly in the period since early 1973, have undergone many changes which have led to shifts in the profitability of mining companies. This paper examines the sensitivity of a selected, broadly based sample of Australian mining companies to the changes that have occurred, or are reasonably likely to occur, in taxation legislation. In the past, tax systems have been altered for a variety of reasons, such as 1. reduction'in the impact of inflation 2. neutralization of incidence between different sections of the economy 3. as an incentive to encourage expansion and growth in a particular industry or area, and 4. increase in the real "take" of government. In this paper, conventional rate of return analyses are applied in a study of how profitability is affected under various taxation systems.

Jan 1, 1977

By I Haine, J Penm, T Waring

During 1999 there was a considerable turnaround in world prices for most minerals and energy commodities, except for the bulk commodities (coal and iron ore). The main reasons for this turnaround were: improved prospects in demand for most minerals and energy commodities in the Asian region following a return to both economic and industrial production growth in key economies in that region; continued moderate growth in demand in Europe and North America; substantial production cutbacks in a range of minerals and energy industries; effective reductions in the supply of oil by OPEC nations; and an announcement by European central banks that they would cap the amount of gold they sell and loan in the next five years. Most of these influences are expected to be sustained into the first years of the new millennium. In 2000, with exception of coal, average world prices of minerals and metals are forecast to rise significantly. Gross domestic product and industrial production is expected to grow in some European countries and most Asian countries in 2000 and, with moderate growth expected to be sustained in the United States, demand for minerals and energy is expected to increase. AustraliaÆs main bulk commodities, iron ore and coal, saw prices set for 1999 - 2000 at substantially lower levels in negotiations in early-1999. Double digit price cuts were locked in. However, similar falls appear to have been avoided for coal in Japanese Fiscal Year 2001, while increases of between four and six per cent were achieved for iron ore. Forecast modest recovery in economic growth in Japan and increasing demand elsewhere in Asia are expected to lead to tighter market conditions in 2000. Beyond 2000, world minerals and energy markets will be influenced by the expected robust global supply responses of minerals and energy companies, against a background of sustained economic growth and industrial production growth in major consuming countries. Over the medium-term, a return to declining real prices which have been evident for most commodities in the recent past, is expected as exploration, mining and processing technological change and associated productivity growth continues to reduce industry costs. While lower rates of exploration and mining investment in Australia between 1998 and 2000 will modestly constrain the rate of future industry expansion, Australia remains an important contributor to expected growth in global minerals supply over the medium-term. Australian mine production is forecast to grow between 1999 - 2000 and 2004 - 05, boosted by production from recently commissioned mines and minerals processing facilities and comissioning of other projects at advanced stages of planning.

Jan 1, 2000

By I Govender, T L. Moodley

Tumbling mills are grossly inefficient, using only 5 per cent of the total energy supplied for actual breakage. A significant proportion of this inefficiency is unavoidable owing to geometric limitations; rotating drum systems are prone to exhibiting certain regions (energy barriers) that resist particle entry thereby restricting the transfer of energy. Though such systems are inherently inefficient, improved modelling schemes may lead to slightly enhanced efficiency through better microscale predictions of key breakage drivers (stress, force). Central to achieving such incremental advances is the development of a universally accepted rheology for dense granular flows. Armed with a better understanding of these macro-scale ingredients, classical process modelling offers an efficient, spreadsheet friendly framework for recovering the spatial distributions of the comminution drivers. At this real-time level of process control, it should be possible to tune comminution operations towards more energy efficient configurations – the ultimate goal of this research. The present work employs validated DEM data to recover the full continuum field which will ultimately serve as a basis for calibrating process model outputs based on different rheological hypotheses. Such a continuumbased approach captures tensor properties like the shear stress and strain rate – both of which are necessary to developing a dense granular rheology. Moreover, DEM captures this data at the momentum transfer timescale of 10-6 s – no other measurement technique is capable of this level of spatial and temporal resolution. Importantly, the confidence in this DEM data is strengthened because it has been validated at the continuum scale using Positron Emission Particle Tracking (PEPT) kinematic measurements. Validated DEM data is derived from batch experiments conducted within a 300 mm ID laboratory drum using three and five millimetre glass beads at 60 and 75 percent critical speed; such mill speeds are typically encountered in the tumbling mill industry. Dimensional analysis is conducted using critical rheological parameters (shear rate, shear stress, granular temperature etc), which are key to not only developing a granular rheology but ultimately will be used to tune our mechanistic models.

Aug 24, 2022

By P Ormsby, T Hewitt

Ore in pillars constitutes a significant proportion of the ore reserve at PasmincoÆs Broken Hill Mine. Many of these pillars are narrow (5 -6 m) and high (16 û 35 m) vertical blocks. High-grade ore has been left between primary horizontal cut and fill stopes. These stopes were mined from the late-1960s until the early-1980s. Fill material is a variety of hydraulically stowed sand, sand-cement, and remnant timber support. Many pillar cut-throughs were made between the old stopes. In order to gain access for the current pillar recovery operations, it has been necessary to develop pillar drill drives through, and adjacent to, the hydraulic filled stopes. Whilst long hole recovery of vertical pillars is not new, some notable successes using innovative ideas have been achieved during 1997. These innovations include:The use of steel mesh reinforcing in shotcrete when mining through, or adjacent to, hydraulic fill. Construction of steel sets to support vent rises and haulage ways encountered in the cut-throughs. The use of ground movement monitoring equipment. Survey lasers with chain droppers and convergence monitors were installed in the 18 Pillar to detect any movement of the pillar block and decrease risk to personnel. The development of a three-dimensional computer model of primary stoping, using Vulcan software, to assist in the design of pillars. Maximisation of recovery using different drilling and firing practices.

Jan 1, 1998

Traditionally, surface coal mines in the Western United States have been limited by economics to depths between 150 to 200 feet. Utah International Inc., however, is now planning to strip coal its San Juan Mine in Northwestern New Mexico to depths ranging up to 400 feet while uncovering 20 feet of steam coal. This method is cost-competitive with nearby shallower coal deposits and underground mining of the same property. How trucks and shovels can pre-strip for a dragline, along with results of the planning process, comparison with alternate systems, capital requirements, operating costs and comparisons with other coal sources are all detailed. Also discussed are the major problems anticipated, how they might be corrected, and potential improvements to the concept. Introduction The San Juan Deep Stripping Project will be situated at Utah International's San Jean Mine. The mine is in the Four Corners region, so-called because four states enjoy a common border point about 30 miles to the northwest.(see Figure 1). The area is a semi-arid plateau region with an average elevation of 5,200 feet, receiving an average of 6 inches of precipitation annually

Jan 1, 1981