Search Documents

THE absence of any locality maps of the district of Morobe has been seriously felt by mining engineers engaged on the goldfields, and as it was evident at the beginning of operations that the administration would be unable to make good this deficiency, ascheme for making rapid traverses was worked out, and in all subsequent travelling the necessary records were kept for the construction of a reliable reconnaissance map of the Bulolo goldfield and its approaches (see Plate 1.). Since all the field work had tobe carried out without encroaching on primary duties, the compilation of sufficient data was a somewhat lengthy business. It was found that in this r;ough country a pedometer was useless, as it was impossible to calibrate it for the variation in length ofpace between climbing semi-precipices and walking over level country. Further, the native tracks "meander" so excessively that the only method of calculating air-line distance is by timing, and a knowledge of what the timing represents, and until a 10kg experience had been gained in the time taken to cover known distances in various types of-country, one could not feel competent to estimate sufficiently accurately. It was found that reliability could be attained only when walking at nearly top pace. Inregard to aeroplane traverses, results were reliable only when the air was fairly still.BEARINGSIn arriving at the bearing between main traverse points, the method used was to keep a "boy" about two chains- behind when marching and sight back on him, standing, at about two-chain intervals. These bearings were averaged into the field book at the end of the day, each line being averaged separately. As the roads became known, it was possible to get a considerable amount...

Jan 1, 1928

By S Arthur, J Mills, A R. Penney

A key aspect of seismic management for narrow vein stoping of the west zone at the Beaconsfield Gold Mine has been the development of a fully remote extraction method that does not require personnel access to sill drives within the orebody once stoping commences. Initially, sill driving within the reef is undertaken in a conventional fashion under geological control. Sill drives are developed at a vertical backs-to-floor height ranging from 7 - 12 m. This mining stage includes all activities prior to the commencement of stoping, after which no personnel enter the unstoped section of the sill drive at any time for any purpose. The key aspect of the remote mining cycle is the use of footwall drill drives paralleling the ore drive at a minimum separation of 6 m under survey control. These drives provide the platform for fan drilling of the orebody. Up to 20 m strike panels are blasted in a single shot using electronic blasting techniques. Ore is mucked from the extraction level sill drive using tele-remote loaders. Aerials for tele-remote operation are installed through boreholes from the footwall drive, negating the need for personnel access to the sill drive. Once mucking of a stoping panel is complete, a laser scanning survey instrument is used to survey the final void for subsequent design and production reconciliation purposes. The survey instrument is mounted in the bucket of the tele-remote loader, and is also operated remotely. Finally, tele-remote loaders are used to dump waste rock fill from the upper sill drive. A system of flags and cameras installed in boreholes from the footwall drive assists the operator in locating the live stope edge during the filling cycle, again negating the need for personnel access.

Jan 1, 2008

The complexities of mining in current economic conditions, where ore extraction schedules are varied on a weekly basis so as to ensure constant supply to the process plant, can result in a number of scenarios that pose geotechnical challenges. This paper presents a case study where alterations in the mining schedule of a particular mine resulted in the necessity to mine under a large uncompacted embankment, ie integrated tailings and mine waste land form. To effectively ensure that ore recovery was maximised, a well-designed slope monitoring system to evaluate design performance and to provide timely warning of impending failures was imperative. In order for an appropriate slope monitoring strategy to be developed, a thorough understanding of the potential slope failure mechanisms, capabilities and limitations of available monitoring techniques is required. Communication of the monitoring results and response strategy to alarms generated by monitoring systems must also be carefully considered to maximise effectiveness. The results of preliminary stability modelling can be used to guide the design of a monitoring system, which in turn can then generate data which can be used to iteratively refine the geotechnical model. This paper illustrates the development and implementation of a slope monitoring system and associated communication system, using the Daydream embankment at Fortescue Metals Group's (FMG's) Cloudbreak Operations as a case study.

May 1, 2010

By S Paciornik

The traditional trading of iron ores is based on chemical specifications and particle size distribution. However, recent characterisation studies, that bring additional information like mineralogical composition and microstructural (textural) aspects, have become important. They contribute to determination of the iron ores downstream beneficiation operations and subsequent steelmaking processing, allowing improvements on both new and existing processes. Despite progress in commercial scanning electron microscope/energy dispersive spectrometer (SEM/EDS) automatic instruments in the last decade, these systems are not capable of performing the identification and discrimination of major iron ore minerals (haematite and magnetite) and the consequent description of its microstructure. On the other hand, reflected light microscopy (RLM) can easily distinguish the iron oxides by their reflectancies, but it cannot discriminate quartz and epoxy resin, which present similar colour on images. The present work proposes an innovative method to perform a quantitative mineralogy characterisation of iron ore based on RLM-SEM co-site microscopy. This technique combines images obtained by RLM and SEM through an automatic registration procedure that accurately aligns the two kinds of images of each field. In fact, it creates multi-dimensional images, which are then analysed using image processing and pattern recognition techniques. The case study is an itabiritic iron ore from Quadrilßtero Ferrffero (Brazil) which contains mainly quartz, goethite, magnetite and haematite. The discrimination of phases that are not distinguishable with either RLM (epoxy resin and quartz) or SEM (haematite and magnetite) can be performed through this multimodal approach, allowing the subsequent mineralogical quantification. The mineralogical quantification computed by image analysis was consistent with independently obtained results based on the Rietveld technique.

Jan 1, 2008

This paper aims to provide some' new and original thoughts on tungsten carbide drill-bits and describe practices and performances, some of which are unique and most of which have not previously been described. Many theoretical and descriptive papers and articles on carbide bits have appeared during the last few years, and in the big majority conclusions such as these were made. These results are marked by premature failure of the bits, or The full or economic life of the bit is seldom reached due to the premature failure of the insert. Unfortunately those conclusions are seldom accompanied by the reasons for premature failure. In the few cases where reasons for failure have been advanced, very little, originality has been shown. The reasons usually given are that the failures are due to bad operators, bad workmanship, faulty steel or unsuitable machines, but it has been shown at Mount Isa that the chief reason for poor performnce is bad design.The first question asked will be, "What is wrong with the design of most bits?" and the answer'is, "The size of' the inserts". There may be many other small faults iiI different types of bit but Mount Isa experience indicates that the size of the insert is the most important factor influencing pit life. Under normal conditions it has been found, that there is a minimum size of insert that will give satisfactory performance, and this minimum is 5/16 in width and ? in. depth at the shoulder. A big majority of the bits at presentavailable in Australia do not satisfy these requirements.

Jan 1, 1953

By Weyer J

Many existing computer planning programs for the mining industry focus either on big mining enterprises with a high production rate or on smaller operations for high value minerals. Big mining enterprises, like the hardcoal company `Ruhrkohle AG' in Germany have their own R&D departments which develop powerful computer programs for planning purposes, partly in co-operation with mining universities. However, there is a remarkable number of small- scale mining operations which are either not able to buy expensive hard- and software or don't have the skills for the operation of extensive software programs. Partly there is also a trend in using rule of thumb calculations rather than computer programs which need a lot of - partly unavailable - data. For this reason a computer program was developed which does not need expensive hardware and software and which can help the planning engineer in the selection of a limited number of possibilities. Until this time the planning engineer established two or three different cases and calculated the results with a pocket calculator. This could last some hours or even some days. Now he or she can use the computer program with a normal PC to compare the cases. All activities are menu-driven. The basis for all, calculations are fixed and variable costs as well as average performance for special activities. The paper gives an example for a possible planning situation in fluorspar mining (originally this program was developed for the fluorspar enterprise Lengenfeld in Germany). It shows the initial situation, the main structure of the program, the input logic and the results. Benefits, limits and possible extensions of the program are discussed.

Jan 1, 1995

By D Clarke, R Simpson

The Main lode in the Anwia Gold deposit is difficult to interpret due partly to the fact that three separate grid and drill hole orientations exist over the area and partly due to a lack of understanding of the controls on the high-grade mineralisation. Scattered high gold grades and multiple veining orientations add to the confusion. Sectional interpretations of the lode are often misleading due to the multiple orientations of drilling. Initial attempts to define a high-grade constrained geological model were not successful due to the inability to establish any geological continuity that would hold together in three dimensions. As a consequence the initial geostatistical domaining for the Main lode at Anwia comprised a simple broad mineralised envelope split by the weathering profiles. Subsequently an analysis correlating subjective qualitative logging information with grade plus utilisation of LeapfrogTM software, together with extensive geological re-interpretation resulted in the definition of a coherent high-grade shoot within the Main lode. The resource was re-estimated including this new domain as a high-grade hard boundary. Estimations on both models were carried out using uniform conditioning, which is a recoverable resource estimation methodology that estimates tonnages and metal above a series of cut-offs for SMU (selective mining unit) sized blocks. This paper compares the tonnages and metal contents that are calculated from the two estimation runs, both at a zero cut-off and a series of higher cut-offs. The results confirm that the estimation methodology has been implemented correctly as the tonnage and metal content at zero cut-off is the same for both models. The resource tabulations and grade tonnage curves predicted by the two models highlight the differences that can occur at higher cut-offs when realistic high-grade domaining is implemented. The results also reinforce the point that recoverable resource models are intended to address selectivity issues and are not substitutes for good geological modelling. Recoverable resource techniques, such as uniform conditioning, will not correctly estimate high-grade zones that have not been explicitly modelled.

Jan 1, 2006

Author Biography William Poole was born in Sydney, NSW in August 1868. He was educated at Sydney Grammar School. William spent two and a half years as a cadet in the Railway Construction Branch of the NSW Department of Public Works doing office and field work. He then undertook a civil engineering course at Sydney University. Following this he was employed for six years as assistant and resident engineer at the Water Conservation Branch, NSW and was in responsible charge of various field operations, surveys, river gaugings and works of constructions including a large timber weir and also a concrete weir on the Macquarie River, NSW. He then undertook a mining and metallurgical course at Sydney University and became a graduate (BE) with honours in civil engineering, mining engineering and metallurgy. He then spent four and a half years with BHP Co, one and a half years at Broken Hill in the mining and concentration works and three years at the smelting works in Port Pirie, SA, in the latter case he was metallurgist and night superintendent and during that time had responsibility and control at night of the blast furnaces and, during the last 15 months, of the whole of these large works. The author left the Port Pirie, SA works to assume the position of Director of the State School of Mines at Charters Towers and had responsible control of the establishment and also lectured in mining, surveying and structure. William Poole was honoured to hold membership in the following organisations: Assoc M Inst C E, L S of NSW, M Aus Inst M M, Assoc Inst M & M (London).

Jan 1, 2006

As a basis for my address to you tonight I thought it might be opportune if we considered the great history of the mineral industry in Australia, and the contribution it has made to the development of the country. While it is perhaps interesting to review the achievements of the past there is also the opportunity to examine the developments of the future.The names generally given to the three periods of man's life on the earth-the Stone, the Bronze, and the Iron Ageand to which should perhaps now be added the Atomic Age, imply the vast importance of the progressive steps in 'man's discovery of minerals and the means of working them. They tell the story of his advance from the flint knife to the bronze celt, and then to the keen-edged iron weapon, and now to the possibilities of the peaceful application of atomic energy. Not only have the stories of gold, iron, copper and tin told a great deal of the history of the progress of mankind, but they have also traced the commercial and industrial growth of Australia over the last century.Gold in the 1850's was responsible for the most significant period of immigration Australia has ever had-when the population almost tripled in the ten years to 1860. Minerals were also responsible for opening up Australia and determining the pattern of settlement. As mineral finds were made, railways were constructed to these fields, then agricultural development followed.Then, as the industrial era started, minerals provided the raw material for Australia's rapid industrial expansion, and they have all contributed to the extent that they have made...

Jan 1, 1960

By Hanley J

Coal winning in the Latrobe Valley exceeds 45 mtpa uses a small number of Bucket Wheel Excavators and high speed conveyor systems. While this equipment offers many advantages in the production cycle, incorrect use can lead to low productivity and risks to the safety of the operators and equipment. The mining equipment is of high capital value and easily damaged when used outside the correct operating range. In the extreme case, this can result in total machine collapse, having major implications for personnel safety as well as production and costs. With an active productivity improvement program in the Latrobe Valley in the last two years resulting in a 50 per cent reduction of personnel, many experienced operators have retired. Mine management are facing the urgent need to rapidly train new operators to maintain high productivity levels and reduce the risk of accidents to personnel and high capital cost plant. With the assistance of the Central Gippsland College of TAFE a Certificate Level course has been developed for open cut operators. The course covers all essential training needs for the Latrobe Valley mines. The training is developed from National Competency Standards, allowing transfer of skills, and is flexible to suit other enterprises. It has been written for self-paced learning with the total job understanding, and to have competency-based learning outcomes, training tasks and assessments built-in to modules. With the introduction of this new training program, management is convinced that the element of risk within the mine will be significantly reduced. For these reasons it is an ideal training model for other enterprises.

Jan 1, 1994

The original leases making up today's North Kalgurli Mines were developed by independent companies on an ad hoc basis. The major disadvantage which now arises is the varying levels of mining horizons. From Kalgurli Shaft in the south, through main Shaft and to Croesus Shaft in the north, there are three separate sets of levels. work has commenced to link the three areas with either common levels or new development which will facilitate common access and haulage via Main Shaft.Generally, the workings at North Kalgurli were established at the turn of the century. The introduction of techniques and equipment to bring the mine into the 20th Century has been difficult and slow. The general size of openings, a widespread workforce and complex ore distribution often make innovation and change more than a challenge.

Jan 1, 1985

DuPont is a chemical and energy multi-national of approximately 90,000 employees. Often regarded as the world leader in injury reduction and process safety management, DuPont operate 140 manufacturing sites around the globe. Conoco is a wholly owed subsidiary of DuPont which is involved in oil, gas and coal exploration.   Throughout this paper I will discuss DuPont statistics, developing a safety culture and training process as well as discussing possible short comings in the New Zealand safety focus. I will conclude with my recommended improvements and issues for New Zealand companies to focus on.   It is very difficult to compare DuPont and New Zealand statistics through lack of compatibility in recording methods and my ability to interpret ACC's Injury Statistics. However through considering DuPont's statistics, and comparing them to your own companies or departments, you will agree they are indeed impressive. I hope that by discussing DuPont's safety philosophy, and possible shortfalls within New Zealand Legislation many of you will find ideas and inspiration which will help you to further reduce your own injury rates.

Jan 1, 1997

A standard practice of auditing mill designs has developed in the mining industry. The purported aim of this task is to ensure that the mill being offered conforms to the design specification, thus reducing the purchaserÆs risk. However, careful examination of the auditing methods used in the past shows that this is not the case. In some cases, what auditors have been providing is effectively a quality assurance check of the input data, not a full independent audit of the vendorÆs design. It will be shown that these past auditing methods have contributed to the stagnation of mill specification development. This lack of specification improvement combined with the current trend towards increased allowable fatigue stress ranges can result in an increase in risk for the purchaser.

Jan 1, 2002

By M P. Sandy

Some Western Australian underground mines are challenged by very high stress gradients. This environment frequently results in poor induced ground conditions and damaging seismic activity. In some cases, rockbursting or squeezing ground has been observed as shallow as 250 m below surface. Very few mines operating at depths greater than 500 m experience no stress-related issues. As a general result of this difficult environment, there are a growing number of mines that are now challenged or have been closed by induced geotechnical problems. Often, the up-front savings or perceived advantage of an inappropriate mine plan may be entirely lost to the real cost of managing the hazards, or a write-down of reserves resulting from access difficulties will diminish the economic position of the mine. From an engineering perspective, it is best if stress-related hazards can be proactively minimised, because reactive measures offer less improvement in risk exposure. In this paper, some examples of sequencing techniques for managing difficult environments are contrasted with examples from mines where developing hazards have adversely affected production or the economic viability of the project.

Jan 1, 2003

By Richardson G. W, Yap L. C

Friction rock stabilisers (FRS) are steel-based, thin-walled tubular ground reinforcement widely used in underground mines in Western Australia. Following installation these stabilisers are subject to corrosion which may reduce the load carrying capacity and lead to unexpected ground falls. Although corrosion has been recognised as a common occurrence, particularly under aggressive mine water and mineral conditions present in underground mines, the knowledge of the effects of corrosion on the mechanical behaviour of FRS is limited. The Department of Minerals and Energy of Western Australia has conducted a laboratory based program of studies to investigate the effect of corrosion on the mechanical properties of FRS. The studies have focused on the effect of corrosion on tensile strength of FRS and frictional resistance along the interface between FRS and the drillhole wall. The results indicate that under certain conditions corrosion damage can significantly reduce the effectiveness of FRS.

Jan 1, 1996

By I P. W Chau

Construction of twin stacked railway tunnels through mixed ground conditions in the heavily populated urban environment of Hong Kong, including tunnelling in poor ground conditions, with low cover and under or adjacent to sensitive structures with minimal impact was the challenge presented by the tunnelling section of the Kowloon Southern Link project. This paper details how twin 1.1 km tunnels of 7.0 m internal diameter were driven by Mixshield tunnel boring machine (TBM) in mixed ground through one of the exclusive shopping and hotel districts in Kowloon. The paper addresses the challenges required to be considered and managed for the success of the project, including ground conditions, TBM selection, Mixshield TBM operation, settlement monitoring and control, ground- borne noise and vibration, proximity to utilities, buildings, roads and operating railways.

Jan 1, 2008

By Slattery T. E

Recent develognents in zinc flotation at the North Broken Hill Limited concentrator are discussed. An outline of the history of zinc flotation and a description of current practice is presented. Installation of on-stream X-ray analysis probes has resulted in inproved metallurgical performance and focussed attention on automatic control. Results are presented of investigations made over the past six years which have led to the formulation of experimental schemes for the automatic control of zinc flotation.

Jan 1, 1983

By A J. Tucker, L Bottomley

The principle objective of development mining is to create thoroughfares that can be accessed by personnel and machinery for the entire life of an underground mine. The drill and blast process, being the primary method used when creating these thoroughfares, needs to be able to adequately fracture the rock to be removed whilst at the same time minimising any damage that may be sustained to the rock surface that remains. This process of damage prevention is known by a variety of different names including smooth blasting, sculpture blasting, contour blasting and controlled blasting. Whilst the terms are different, the objective is the same and that is to reduce and better distribute the explosive charges to minimise stressing and fracturing of the rock beyond the neat excavation line. The process in this report will be referred to as perimeter control blasting. This paper will discuss the benefits of using perimeter control blasting in a development mining operation and the theories that govern how these blasting techniques work. The methods that are used to implement perimeter control blasting will also be addressed, paying particular attention to how these blasting techniques have evolved, spawning new and improved perimeter control products. Finally some attention will be given to the process of optimising perimeter control blasting in any underground mining operation.

Jan 1, 2005

By B C. Povey

HPGR technology has been used at a number of magnetite mines in the world and have significant energy advantages over SAG and AG technologies. The early design at Los Colorados in Chile has been in operation for more than 12 years - and operates very successfully though only reduces the feed size to -5mmThe Whyalla project magnet design pushed the concept to produce a preconcentrate of 80%-350micron - a significant reduction on previous plants though with some wear problems in the early years. The Karara design backpedalled slightly and will only crush to 80%-1.8mm.However, the design issues of using a HPGR to further reduce the feed size continue to be explored. The aim is to reduce the process risks associated with wear and also to reduce the complexity of the downstream process - with consequent benefits in terms of capital and operating costs.The designs are being developed for a couple of projects - one planned to produce 20Mtpa of concentrate with the potential to not only remove SAG and AG milling but also ball milling. The concept is to use multiple passing through the HPGR since, on the data available, the efficiency of the HPGR to reduce size does not significantly diminish as the feed size is reduce. This can be have benefits in both capital and operating cost.CITATION:Povey, B C, 2013. Pushing the use of high pressure grinding rolls in magnetite circuits, in Proceedings MetPlant 2013 , pp 176-189 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By R Linares

The efficient operation of any modern metallurgical facility depends on the accurate measurement and estimation of flow rates, inventories, and composition of their intermediate and final products. All of this information is subject to both statistical errors and gross errors, which can lead to poor estimation of efficiency, yields and specific energy consumption. The detection and the elimination of these errors require not only plant data, but also product transactions and the operational events. Once the gross errors have been eliminated, it is possible to estimate validated performance indicators, such as grade recovery or yields. This paper describes the methodology to implement a unification and gross error detection system using the available infrastructure of both information and data reconciliation system. It covers the different infrastructure layers, from the data collection layer to the data validation and reconciliation layer. In addition, the impact of these methodologies on the decision-making process is presented.

Jan 1, 2005