Search Documents

By B Walker, A Robertson, C Wels, S Fortin

A background characterisation study was carried out in the Sangre de Cristo mountains, New Mexico, to: quantify naturally occurring contaminant loads from mineralised areas; define site-specific background concentrations; and to determine key factors controlling spatial and temporal variations in contaminant concentrations. The study included a comprehensive sampling and testing program (paste pH/EC, ABA, leach extraction tests) of soil/bedrock from mineralised areas (including erosional scars), and a ground water and surface water quality monitoring program in selected mineralised watersheds. Results demonstrate that high concentrations of contaminants occur naturally in ground and surface water draining the mineralised area of the Red River basin. The erosional scars were found to represent the major source of acid rock drainage (ARD) (~66 per cent) in this area due to: high rates of weathering and erosion, which continually exposes sulfide-bearing outcrops; and high rates of run-off as a result of high elevation and lack of vegetation. The scar material is generally very acidic (paste pH ranges from 8.5 to 1.5; average = 3.6) with highly elevated concentrations of sulfate and leachable metals. The composition and concentration of leachable metals vary significantly, not only between scars but also within a given scar. While all streams draining the various scar watersheds are highly acidic, each has a characteristic æfingerprintÆ of sulfate and metal concentrations. Most of the run-off from the scars infiltrates into alluvial debris flow aprons and reaches the Red River via groundwater flow.

Jan 1, 2003

By Baafi EY

Open cut mining in Australia is facing the greatest challenge in its history in attempting to compete not only with other operations internationally, but also with underground operations domestically. Most flat dip and shallow depth surface-mineable coal reserves have been depleted during the last two decades and new open cut operations must extract deeper coal deposits. As open cut coal mines move into deeper areas and the stripping ratios increase, the relative cost of overburden removal also increases. It therefore becomes even more important to design the mine around the optimum overburden removal scheme. The deeper mines are usually multi-seam operations with a more complex geology and with more geotechnical and hydrological problems. Deeper mines are subjected to greater problems requiring more detailed mine planning and design, such as selection of the optimum mining method and pit layout. In planning and design of such operations, the number of alternative methods which need to be considered is consequently greater.Dragline productivity and its stripping capabilities are directly affected by the selection of digging method, strip layout and pit geometry. Every mine has a unique combination of geological conditions. The operating methods that work well at one mine may not necessarily work at another site. Selection of an optimal stripping method, strip layout and pit geometry for a given dragline must be considered with respect to the geological conditions of the mine. With increasing geological complexity of Australian strip mines, it is becoming more important to use sophisticated techniques such as computerised mine planning methods to assist in optimising dragline operations.

Jan 1, 1998

By Gyasi-Agyei Y

In recent years rapid advances have been made in the technology used for hydrology and erosion modelling of rural catchments. These advances have been driven by the growing availability of digital terrain maps that can be used to automatically define catchment properties that previously had to be manually extracted from contour maps. In addition, these models have, in principle at least, more powerful predictive capability. The author is involved in a number of projects to migrate and further develop these models for application to mine rehabilitation assessment. Current technologies for hydrology and erosion assessment (eg CREAMS, ANSWERS) are reviewed, underlying principles highlighted and deficiencies in the context of mine rehabilitation design assessment addressed. The advantages and disadvantages of the new digital terrain map tools (eg WEPP, SIBERIA) are discussed. Current work integrating these new models with existing rehabilitation design tools (eg ACIRL's ARGUS computer package) highlights the advantages of an integrated approach using digital terrain maps; cheaper, faster, lower impact and more flexible rehabilitation design. The use of novel visualisation tools to aid the design process is discussed. The paper is illustrated by applications to mine sites in Queensland and the Northern Territory.

Jan 1, 1995

Ok Tedi Mining Limited commenced construction in mid-1981 of facilities and infrastructure to mine and process gold ore at Mt Fubilan in Papua ew Guinea. Production ofgold began more or less on schedule in mid-1984 although design capacity is yet to be achieved. Due to geotechnical problems, two important items of infrastructure, hydropower and permanent tailings disposal, are not yet in place. Current low metal prices make it likely that copper facilities will be postponed.The deposit compriscs a leached gold capping overlying copper sulphide porphyry mineralisation containing significant gold and molybdenum. Mining is by open pit methods. The soft leached capping gold ore is ripped and dozed, loaded by hydraulic shovel and trucked to a dump pocket. After passing a large semi-autogenous mill of nominal capacity of I, I00 tonnes per hour, the ore is treated by the carbon-inpulp process, with a gravity circuit to recover coarse gold. The final product is 12 kg dore bullion bars.At present, all tailings are detoxified with hydrogen peroxide; after cycloning, the coarse fraction is stored, and the slime fraction discharged into the river system; expected environmental impact is acceptable. Investigations for a suitable dam site for a permanent tailings system are still underway.Peak 'I. hour power demand for Stage I is 17 MW, presently supplied by a diesel alternator power station and a 2 MW mini hydropower plant.Initial access to the base camp at Tabubil was only by air. Eventually a road was pushed through 134 km from the river port at Kiunga (where port facilities have been constructed) and a further 23 km to Mt Fubilan.Roads are constructed of compacted gravel and crushed limestone generally underlain by geofabric. Eight major steel bridges were built.The town of Tabubil has been established, including housing, airport, shops, offices, schools and all facilities.Environmental studies have been extensive and a detailed monitoring program is maintained. Ok Tedi Mining Limited is making considerable efforts to train Papua New Guineans and to foster local business.

Jan 1, 1985

By Riley S. J

Ranger Uranium Mine is located within the Alligator Rivers Region of the Northern Territory of Australia and surrounded by the World Heritage listed Kakadu National Park (Figure 1). The mining operation is currently producing about 1500 tonnes of uranium oxide annually, as well as considerable volumes of waste rock, low grade ore and tailings. The rehabilitation of the project should ensure that the radioactive mill tailings and other contaminants remain contained for at least 200 years, as required by the existing guidelines (Commonwealth of Australia, 1987). The present uranium mining operation is regulated by the Northern Territory Department of Mines and Energy who must refer to the Environmental Requirements when considering regulatory options. These Environmental Requirements were agreed by the

Jan 1, 1994

Geomechanics is one of the more specialised aspects of site supervision on a major tunnell- ing project. The controlled deformation of a rock mass as a result of tunnelling and the knowledge of loading of temporary and permanent underground supports are important for safe, economic construction. These basic parameters depend on the construction method and sequence and the geological conditions through which a tunnel is driven. Thus geomechanical monitoring during the construction phase provides feedback to a design team and allows any revisions to a design to cater for local conditions not revealed by earlier investigations. Detailed geological mapping is an integral part of geomechanics in the construction phase. It serves as a monitor on pre construction predictions and also forms part of the as- constructed record. If conventional excavation-techniques are adopted, geomechanics can provide a service of blast' vibration monitoring of surface structures in urban areas.

Jan 1, 1976

By M I. Pownceby, N Karimian, A Frierdich

These may be found with goethite through mechanisms including direct substitution or coprecipitation of nanocrystalline phases. Understanding P incorporation in goethite has significant implications for Australia’s iron ore industry as it lowers their commodity value. The current study tests a novel low-temperature technique to extract P impurities from synthetic goethite phases under O2-free ambient conditions by utilising Fe(II)-catalysed recrystallisation. The objective of this study was to examine the effect of the Fe(II)-catalysed recrystallisation of goethite on the geochemical behaviour (mobility and speciation) of co-associated P. To achieve this, we tracked changes in labile P (aqueous and 1M NaOH extractable) concentrations over time in goethite suspensions which were reacted with Fe(II)aq for 14 days under circumneutral pH conditions and room temperature conditions. Temporal changes in Fe mineralogy were investigated via synchrotron-based X-ray absorption spectroscopy. Iron K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy confirmed goethite as the only mineral phase in P-free treatments while goethite (~86 per cent) and feroxyhyte (~14 per cent) were the main phases in 1.0 per cent P-containing treatments after a 14- day reaction with Fe(II)aq. According to our findings, the treatment of P-goethite with Fe(II) for a duration of 7–14 days, followed by a 24-hour extraction of the reacted solids using 1M NaOH, results in the removal of approximately 79.5 per cent of the initial P content. This removal encompasses both the aqueous fraction (~4.5 per cent) and the surface adsorbed fraction (~75 per cent) from the 1 per cent P-bearing mineral phase. Notably, this approach demonstrates an improvement in P extractability, with approximately a 10 per cent increase compared to the 1 per cent P-goethite sample that was not reacted with Fe(II).

Sep 18, 2023

This paper describes the MillMapper technology developed for condition monitoring of liners and other operational parameters in grinding mills used for mineral comminution, by presenting a case study of its application. MillMapper provides maintenance engineers, operations managers and process and plant metallurgists with quantitative, accurate and reliable condition monitoring data for informed decision making regarding the maintenance and metallurgical aspects of such mills. MillMapper uses calibrated laser scanners for the capture of three-dimensional surface representations inside a mill during a shutdown so as to determine shell, feed and discharge liner thickness at a resolution of several million data points, a procedure that nominally takes five minutes to complete. Once several data sets over time have been collected inside a mill, MillMapper can be used for liner wear, liner wear zone, liner weight, ball charge volume, ball charge weight and intelligent profile tracking over time. Liner tracking in combination with site defined reline and failure criteria and with throughput tonnage data is utilised for change out prediction of each separate liner segment type.

Jan 1, 2008

By Durucan S

The southern Attiki peninsula is a very interesting area from an environmental point of view. The port and the city of Lavrio is situated at the east coast of the peninsula with about 10 000 inhabitants and there are also a few villages in the vicinity. The south-eastern part of the peninsula hosts the famous Lavrio mines which exploited the silver bearing orebodies of the area for more than 25 centuries. As a result, soils around the city of Lavrio are polluted with high heavy metal loads. The area is also of archaeological interest, as there are well preserved remnants of ancient mining and processing plants and archaeological sites. Soil samples collected from an area of approximately 120 km2 around Lavrio were analysed for their metal contents and the spatial distribution of the concentrations of ten selected elements were estimated from these data sets. The spatial data analysis and transformation capabilities of Geographic Information Systems, combined with extensive mining and geological data, helped the authors to identify the extent and causes of metal pollution around Lavrio.

Jan 1, 1995

The world is getting flatter through internet, mobile phone technology, relatively low cost travel, massive outsourcing of manufacturing to China and the transfer of company backroom operations to India. In the iron and steel industry, however, things will remain relatively the same with slow gradual improvements in technology; only the geographic location of plants may change over time. Or will it? The blast furnace smelting process has remained largely unchanged since 1828 when James Neilson came up with the idea of preheated air being delivered to the tuyeres. Likewise, oxygen steelmaking that takes molten iron from such blast furnaces has remained conceptually unchanged since Sir Henry Bessemer invented an air-based system in 1856. These two processes are the core of integrated steel mills that we know today. Typically such mills consist of coke ovens, sinter plant, blast furnace, oxygen steelmaking, continuous caster, rolling mills and metal coating lines. In the intervening 150 years the only real disruptive technology to the integrated steel mill has been the minimill. Based on the use of the electric arc furnace (EAF), in conjunction with a continuous caster and rolling mill, the term minimill is used because steel products are produced at down to one-tenth the scale required for economic operation of an integrated mill, with the EAF producing molten steel using largely scrap steel as its feed, as against transforming coal to coke (coke ovens), iron ore, coke and limestone into molten iron (blast furnace) and molten iron to steel (oxygen steelmaking). There are, however, a number of technologies in development that may cause a paradigm shift in the way steel products are produced and perhaps push the evolution of the minimill as a disruptive technology. Two examples are direct iron smelting, where iron is produced in a matter of seconds by injection of ironmaking feed materials into a molten bath, and thin strip casting, where molten steel is cast into 2 mm strip or less, in similar time. Both have Australian connections. A leading iron smelting technology is the HIsmelt« process, which has its first commercial application at Kwinana, Western Australia, where a joint venture of international parties, consisting of Rio Tinto and the Nucor, Mitsubishi and Shougang corporations, are in the stage of ramping up commercial production. The leading strip casting technology is the Castrip« process that arose from development work done by then BHP Steel, with IHI of Japan, at Port Kembla, New South Wales in the 1990s. Nucor followed this work up, building the first commercial plant for the technology at its Crawfordsville site in Indiana in 2001 and has recently announced an intention to build a second plant in the USA. While both technologies are only into the early stages of commercialisation they are likely to change the face of iron and steelmaking as we know it over the next 20 years. This paper elaborates on the technology of the two processes, why they could change the face of the iron and steel industry forever, what might drive the rapid change and what the changes may look like.

Jan 1, 2006

The risks faced by organisations are part of a risk continuum. They can be evaluated in terms of hazard, uncertainty and opportunity as well as by the degree of influence they have on conformance, operating performance and strategic objectives. This paper discusses the application of risk management techniques for mitigating blasting hazards, reducing blasting output variability, and implementing blast improvement opportunities. Effective risk management practices can identify and evaluate risks across all levels of the continuum and can deliver realistic assessments of the likelihood and impact of risks on the companyÆs safety and business objectives. This paper does not attempt to present technical details about blasting, rather it aims to provide enough blasting context and examples so that the practical benefits of applying the risk management process to blasting can be fully appreciated. The topics discussed include: explosive management plan; statistical process control; quality blasting, rock-on-ground; Blast Management; Mine to Mill optimisation; and blasting information systems. The concept of a blasting risk management system employing a continuous improvement loop is also introduced. On reflection the insights presented should be extremely useful for observing and understanding which risk face has management focus at a mine site or for a blast site.

Jan 1, 2001

By J Cook, S Pike, D Pridmore

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The application of high-resolution seismic reflection to map structure and/or mineralisation in hard rock environments has progressed significantly in the last decade. Improvements in equipment, field practice, processing and understanding has seen the seismic reflection technique emerge as a cost-effective tool for high-resolution three-dimensional structural and lithology mapping to depths far greater and with superior accuracy than other more conventional geophysical techniques.This paper outlines results and preliminary interpretation of 2D and 3D seismic reflection surveys aimed at defining fault zones and locations for quartz load development in favourable host lithologies at the Cracow low-sulfidation epithermal gold system in Queensland, Australia.As this is possibly the first time that high-resolution seismic reflection data has been used to define the structurally-controlled location of low-sulfidation epithermal gold mineralisation, an important aspect of this work was the derisking or due diligence steps taken prior to commissioning the full 3D surveys at each site. This included full wave sonic logging, vertical seismic profiling and trial 2D lines. Interpretation of the 2D profiles and the drilling of interpreted structure provided the confidence to proceed with the full 3D survey.The advantage of collecting 3D data extends beyond ensuring that the received reflections are located correctly in 3D space. The final 3D data cube can potentially map the entire fault network, thus highlighting flexures and changes in orientation of the structures both vertically and along strike, which is an important aspect in the deposition of gold and for direct targeting.CITATION:Smith, R, Cook, J, Pike, S and Pridmore, D, 2015. Application of high-resolution seismic reflection surveys to exploration for blind vein systems at the Cracow low-sulfidation epithermal field, in Proceedings PACRIM 2015 Congress, pp 77–84 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Mining had a very considerable effect on the country's development. The visual evidence remaining is an integral part of New Zealand history. Early mining for manganese and copper in the 1840s was succeeded by alluvial gold rushes. These gave way to hard rock extraction, hydraulic elevation and dredging. Coal mining dating from the 1850s was fairly widespread. Other minerals were obtained on a small scale. Manufacture of mining' machinery stimulated industrial engineering enterprises. Schools of mines played a significant part in advancing technical skills and several remain as museums. Surviving mine structures and site relics are part of the industrial heritage signifying the technological and economic development of a small isolated nation. Some of these are described. Identification, recording and preservation where practicable is advocated.

Jan 1, 1990

Response of a mineral to anionic and cationic flotation reagentsvaries with the nature of the mineral and the particle size. A ruleis deduced for the selection of the correct type of reagent, which leads to a simple method of testing ores to determine the possibility of separating the constituents by flotation.

Jan 1, 1963

By T O Aspinall

The Australian mineral industry involves a diverse range of expertise and skills. Within that, the mining industry, representing mine planning, mine management and equipment operation, has capital intensive, high productivity equipment and a small but skilled workforce. Continuing education for all personnel in the workforce after formal school courses will be an important contribution towards improving competitiveness. The non-tertiary sector represents a significant proportion of the workforce and requires as much attention as the tertiary educated group. Competency Based Training is now being developed for the mining industry in Australia under the National Training Board and the mining industry is well represented in establishing standards and curriculum. TAFE is a major source of accredited courses but some mining companies are also developing internal courses not necessarily for external accreditation. Articulation of such accredited courses to tertiary mining engineering courses has been considered. The education and training of equipment operators through continuing education requires attention to operating skills, an understanding of the productivity factors under the direct influence of the operator and providing product quality to the customer. The education and training of mining engineers has been widely covered and continuing close involvement of the mining industry is required to ensure well balanced courses in technical and interpersonal skills as well as motivation to continue learning for life. Postgraduate research is a part of continuing education but the mining industry has to continually address the adequate recognition of post-graduate qualifications for the increased technical or management expertise and the development of better analytical and problem solving skills which can be directed towards improving competitiveness. More attention has to be paid to providing adequate financial incentives to attract suitable students, particularly after attaining some experience, and to address their professional career path with a company so they are not significantly disadvantaged by undertaking post-graduate studies. The Chartered Professional Engineer status as provided by The Institution of Engineers, Australia to qualified candidates is being considered by The Australasian Institute of Mining and Metallurgy as a further recognition of a member's specific expertise and competence in mining and metallurgical engineering. Continuing education plays a major part in the maintenance of the expertise and competence required for a professional engineer to develop and also to retain chartered status. Continuing education will be a significant part of the education and training of all the mining workforce towards improving the competitiveness of the mining industry. The major challenges will be the motivation of all towards lifelong learning and the integration of the various programs towards providing the opportunity for a steady and satisfying career progression.

Jan 1, 1994

By A P MACONOCHIE

The methods used and some of the results obtained from a major geotechnical study of the Ok Tedi mine area, Papua New Guinea, are described. The study was carried out at both regional and local scales and extended over a two-year period. A team of individual engineers and scientists from a variety of disciplines carried out the work. This study may provide a model for other investigations in similar environments.

Jan 1, 1992

The procedure used for Truck Maintenance is described systematically in this paper. Emphasis is given to manpower required, work facilities, daily maintenance and oil sampling procedure. Scheduled Preventative Maintenance Service, Electrical Service, Component Change, Truck Overhaul and Outside Contractors are also discussed. The system used, achieves the required results with an average haul truck availability in 1981 of 87.9 per cent. INTRODUCTION Situated on the Island of Bougainville, in Papua New Guinea, the Bougainville Copper mine nestles in a valley near the crest of the Crown Prince Range, between 600 m and 980 m above sea level. The mine is serviced by two towns, Arawa - an open town on the Coast and Panguna at the Mine Site. Currently Bougainville Copper operates an open pit mine removing an average of 198 000 dry metric tonnes of material per day (115 000 tonnes ore and 83 000 tonnes of waste) with a fleet of electric shovels and 154 tonne electric haul trucks.

Jan 1, 1982

It is usually the case that the short-term plannerÆs role is occupied by the younger site mining engineer. ThatÆs because mine scheduling is generally seen as a mundane and thankless task. But, short-term planners play an extremely important role in maximising the value of the mining resource, generally the companyÆs biggest asset. A look at any mining operation today will expose the competing drivers behind the operational and strategic plans. Operations are too often faced with pushing short-term constraints. It is the responsibility of the short-term engineer to answer the question of æWhere to next?Æ. In answering this question the young mining engineer is in an environment overflowing with urgency and constraints. Hasty decisions made at this time may have significant adverse consequences to the long-term value of the resource. Long-term strategy must address a broad and expanding number of issues that are generally overlooked by the short-term planner. It takes a holistic, rather than the prescriptive approach of short-term planning to determine the best strategic direction for the operation. To better understand the consequences of decisions made at the operational level short-term planners need better vision of the whole business. The key to improving the mining business is a planning process that integrates the short-term planners role with the overall mining strategy. Future developments in the mine planning process will focus on bridging this ædisconnectÆ between the operational objectives and the long-term goals. Improvements will come from the tools which planning engineerÆs use, and the planning methodology surrounding them. There will be significant hardware improvements to improve the speed with which a short-term planner can evaluate plausible options. Software that maximises the use of the improved hardware will be developed. Complimenting these technological improvements, conceptual methodologies of mine planning will improve to allow strategic planning to be brought within the focus of the short-term planning engineer. In todayÆs mining industry the young mining engineer is embarking on a career where business processes are paramount. This paper discusses the ædisconnectÆ that occurs today between the operational planning and long-term strategy and how this is driving developments in mine planning today.

Jan 1, 2003

By H Bleuler

A new portal and access drift was constructed by Concrete Constructions for BHPÆs Elouera Colliery, south of Wollongong.The portal area at the base of the Illawarra Escarpment is in soft colluvium material, underlain by highly to moderately weathered sandstone. The area has a well documented history of slope movement or slope creep and one of the main criteria for the design was to minimise disturbance to the unstable slope by limiting the excavation for the portal establishment. This was achieved by incorporating a sloped headwall and gabion wingwalls to accommodate the anticipated creep and groundwater seepage.Main features of the design process also included the provision of both primary and secondary support in a single shell application and the use of canopy tubes to provide support ahead of the tunnel face.The active involvement of the designer during the construction phase and the flexibility of the design concept allowed changes to the support methodology to be carried out as excavation proceeded.This paper describes the design process undertaken for portal establishment and access drift to cater for the variability of the exposed ground conditions along the drift alignment.

Jan 1, 1999

Investigations of the Mineragraphic Section; Commonwealth Scientific and Industrial Research Organisation, have included most of the known stannite-bearing ores in Australia, and have revealed several new occurrences of this relatively uncommon mineral. They provide information about its paragenesis, and its possible effect on tin recovery, that may be of general interest.Several of the investigations used in the preparation of this paper, were made in the first instance by pr. F. L. Stillwell or in collaboration with him.CASSITERITE-SULPHIDE ORES IN NORTH-WEST- TASMANIA Stannite is a minor component of most of the cassiterite sulphide ores of north-western Tasmania. These include the orebodies of Mount Bischoff, the Cleveland mine, Moina, the Stanley River district, Renison Bell, and the Heemskirk-Zeehan district, and form a well defined metallogenetic provence which is related to the Devonian granites of this part of Tasmania.In these ores mineralisation began. with deposition of cassiterite, a little wolfram, and quartz, topaz and tourmaline. With falling temperature, deposition of cassiterite ceased and arsenopy-rite, pyrite, and especially pyrrhotite, formed in abundance, tending to give massive sulphide ore. A little chalcopyrite; stannite, sphalerite and native bismuth accompanied the pyrrhotite. Deposition of quartz ceased after the pyrrhotite, was formed, and the later-formed nonsulphide gangue consists chiefly of carbonates and fluorite. With, the advent of the carbonates the pyrrhotite was altered to fine-gained intergrowths of marcasite and pyrite. Excess iron from the pyrrhotite entered the intergrown carbonate, or was precipitated as magnetite. Some solution of the cassiterite occurred at this stage, the tin being redeposited chiefly as stimnite replacement rims around the residual cassitellrite grains. Varying, but small, amounts of sphalerite, galena, tetrahedrite and silver minerals were depoSited at this stage, bringing the mineralisation to a...

Jan 1, 1951