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By P Hanna

Following the Busang fiasco, more detailed guidelines were appended to the latest revision of the JORC Code released in September 1999 (JORC, 1999). Although the definitions and terminology essentially remained unchanged, the additional information in the guidelines has highlighted a number of issues for consideration by geologists undertaking computer-based resource estimations. The three main issues are:Data Integrity û details such as drilling and logging techniques, sampling procedures, assay tests, site visits, data recording and aggregation methods need to be considered. Geological Interpretation û is the Competent Person applying the appropriate software interpretation to the deposit in accordance with the regional setting. Are the correct computer-based tools being applied and are they producing the desired result (without compromise) to the satisfaction of the Competent Person? Modelling Technique û the importance of the relevant experience of the Competent Person not only in regard to the geology, but also with respect to the modelling algorithms and resource calculation methods of the computer software system involved. At the end of the day, it is essential that the Competent Person undertake a reality check on the resource estimation itself. They should also check that the borehole spacing is in accordance with the level of continuity for each critical parameter (such as structure, grade, impurities, etc) for which the resources are categorised.

Jan 1, 2000

THIS paper is not intended to be a detailed description of the lead, smelting plant at Cockle Creek, as this has been covered in previous papers for the Institute in 1918, Proceedings No. 31, by other members of the staff; but the idea is to give some of the practices and conditions peculiar to these works, also to give some experiments carried out and the conclusions arrived at. Unfortunately, owing to the closing down of the smelting and refinery plant at these works, sone of the experiments could not be carried to a more definite and commercial basis, but they are given in the hope that they may be of interest to members, and may perhaps suggest further thought along the lines indicated.ROASTING AND SINTERINGThe greater part of the ore treated at these works came from the Central mine, Broken Hill, but, in addition, a large quantity was purchased from other parts of New South Wales and from Tasmania. This purchased ore was seldom received in the form of a concentrate, but initially in its crude state, and therefore had to be crushed. The crushing was done in a Krupp mill, and the ore then added to the roasting mixture. This addition of crude ore was one of the main...

Jan 1, 1923

Since the earliest recorded prospecting of the 1860's mineral exploration and mining in Fiordland has been discouraged by the formidable physical difficulties presented by its isolation, extremely rugged relief, treacherous coastal waters and generally unfavourable weather conditions. Government assistance was often sought by the miners and prospectors but little, if any, support or encouragement was received after the initial period. During the 1840's decorative marble was quarried at Caswell and Dusky Sounds. A prospector discovered and attempted to mine copper sulphides to the north of Dusky Sound (Parks Mineral Beds) and near Mt Solitary. A small Pb, Zn, Cu, Ag, Au bearing quartz reef was discovered and driven on in the granite coast line of Preservation Inlet (Bradshaws Reef) and the ore roasted on site. Alluvial and quartz lode gold was discovered at Preservation Inlet in the 1890's and led to the recorded recovery of 11 000 oz of mainly lode gold. Falloff in grades with depth, thinning and splitting of the reefs and the high mining costs at this location led to a virtual abandonment of the field by 1906. In the late 1950's and early 1960's the geology of Fiordland was mapped by the Geological Survey at 1:250 000 scale, but field work was largely confined to the shore lines of the coast and fiords. In view of the physical difficulties it is not surprising that mineral exploration and mining up to 1970 was limited to the scant attention outlined above.

Jan 1, 1977

Background A recent development in many industries,' including the mining industry, has been ever increasing acceptance and adoption of extended (12-hour) shifts and compressed work cycles compensated by more time off work by employees between cycles. In the Western Australian mining industry development of `long-distance-commute' (LDC) coincided with adoption of 12-hour rotating shifts. Preludes to LDC were the `construction-style' rosters with two crews plus allowance for annual and sick leave relievers working the statutory 13 consecutive shifts followed by one shift off. Crews rotated day to night shift weekly or at fortnightly intervals. Average hours of 72 to 78 per week were common. The author had personal experience working these rosters in the East Pilbara of Western Australia from 1977 to 1982. Workers tolerated these rosters until a suitable combination of frustration, boredom, despair and the `Five Grand Fever' triggered them to `pull the pin' and head for relaxation in Bangkok, Manila, Nimbin, or Margaret River according to their personal tastes.

Jan 1, 1996

By Revy T

A testwork program aimed to improve the assaying of underground face samples established that for an Accelerated Cyanidation Extraction using the LeachWELLTM 60X catalyst, followed by an Aqua Regia finish (to quantify non-cyanide-extractable gold): ò Assay results (including the aqua regia finish) from a full set of samples from one underground face can be returned within four hours. ò The reagent dose to make the method simple and 'bullet-proof' is 8 gm LeachWELLTM 60X and 20 gm NaCN per 200 gm sample (30 per cent solids). Pulverising is to 90 per cent passing 75 micron (compared to the standard of 90 per cent passing 150 micron), and cyanidation is completed within one hour - however both might be further optimised. ò The LeachWELLTM/Aqua Regia results demonstrate that Fire Assays suffer from a significant nugget effect which makes the Fire Assay data relatively unreliable. ò Original costs, specific to Bannockburn (viz including an Aqua Regia finish), handling approximately 20 000 to 25 000 per annum is estimated to be $5.40, ie about one-third less than fire assaying. Optimising is further reducing these costs. It is estimated that the LeachWELLT"'/Aqua Regia assay procedure has reduced the probable error limits of any given assay of this ore from the range 0.74x to 1.36x for Fire Assay, to an appreciably smaller range of 0.90x to 1.11x. Thus for a cut-off grade of 1.60 g Au/t, samples with Fire Assays ranging up to 2.18 g Au/t have 25 per cent chance of being below cut-off, while samples with Fire Assays as low as 1.18 g Au/t have an equal chance of actually exceeding cut-off grade. This 1 g Au/t range in uncertainty is generally unacceptable for many practicalgrade/tonnage relationships. By contrast, using LeachWELLTM + Aqua Regia assays, the estimated corresponding limits are 1.44 g Au/t and 1.78 g Auk respectively - a far more tolerable 0.34 g Au/t range of uncertainty. Subsequent data has demonstrated that sufficient accuracy for grade control is achieved by Accelerated Cyanidation alone, further halving the cost of assays.

Jan 1, 1994

By F Minz, P Lamberg, A Mwanga, C Lund, C Wanhainen, M Amiri Parian, J Rosenkranz

A geometallurgical model is currently built in two different ways. The first and the most common way relies on geometallurgical testing, where a large number of samples are analysed for metallurgical response using small-scale laboratory tests, eg Davis tube testing. The second, mineralogical approach focuses on collecting mineralogical information over the orebody and building the metallurgical model based on mineralogy. At Lules University of Technology, Sweden, the latter method has been adopted and taken further in four ongoing PhD studies. The geological model gives modal composition by the help of element-to-mineral conversion and Rietveld X-ray diffraction. Texturally, the orebody is divided into different archetypes, and liberation measurements for each of them are carried out in processing fineness using IncaMineral, a SEM-based technique. The grindability and liberation spectrum of any given geological unit (sample, ore block, domain) are extrapolated from the archetypes. The process model is taken into a liberation level by mass balancing selected metallurgical tests using the particle tracking technique. The approach is general and can be applied to any type of ores. Examples of ongoing studies on iron and massive sulfide ores are given.CITATION:Lamberg, P, Rosenkranz, J, Wanhainen, C, Lund, C, Minz, F, Mwanga, A and Amiri Parian, M, 2013. Building a geometallurgical model in iron ores using a mineralogical approach with liberation data, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 317-324 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By P M. Larionov, V I. Zaikovskii

Transmission and scanning electron microscopy together with X-ray spectral microprobe analysis were used to investigate the structure and chemical composition of pathological calcified formations on the bioprostheses of heart valves. Controllable synthesis was carried out under the conditions (T = 37¦C, pH = 7.4) when the ion composition of the main elements (Ca, P, Mg and NaCl) is close to their concentrations in blood plasma. It is proposed on the basis of the obtained results that the formation of the hydroxyapatite of calcific inclusions on bioprostheses occurs as a result of spontaneous precipitation in the blood plasma. One of the factors determining the formation of massive calcified bodies on the bioprostheses of heart valves can be decreased magnesium concentration in blood.

Jan 1, 2008

By R Bresca, A McCallum, J Scealy

The Endeavor Mine, located to the north of Cobar, New South Wales, was purchased by CBH Resources Pty Ltd in September 2003. The operation has been producing lead and zinc concentrate continuously for over twenty-three years. In 2004, a water management program was instigated to improve the raw water use efficiency of the mining operation. The water management program involved the establishment of a Water Management Committee, a review and quantification of water use across the site, investigation and implementation of efficient water use practices, and workforce awareness training. The program has seen the amount of water used per tonne of ore milled reduced from an average of 1.08 kL/t in the March 2004 quarter, to 0.68 kL/t in the March 2005 quarter. This paper outlines the Endeavor Mine water management program and may serve as a model for other operations that are planning to improve their water use efficiency.

Jan 1, 2006

By M D. Kuruppu

Fleet operational effectiveness is fundamental to any operation, becoming highly topical in mines experiencing less than optimal output from their fleets. It is an all encompassing aim to identify those factors that could be improved within production and suggesting solutions in order to optimise the existing fleet and obtain the highest return on capital expenditure. The fleet operational effectiveness of a large open pit truck and shovel operation in Western Australia was examined and a study was undertaken allowing identification of areas falling below target. The annualised hours and production downtimes were investigated to quantify the potential gains of improvements in these areas. The project aimed to maximise direct working hours through determination of the main issues hindering performance. External and internal factors were considered and a continuous improvement program (CIP) was developed. The CIP aimed at internal site-based improvement teams to identify and implement solutions for improvement on a day-to-day basis. Strategies were then identified for the implementation of the proposed changes.

Jan 1, 2003

This paper describes the planning mechanism and implementation of a progressive rehabilitation programme at Hunter Valley Mine in the Upper Hunter Valley of New South Wales. Hunter Valley Mine is a large open cut coal mine which produces approximately 7.0 million tonnes of coal (run of mine) annually for export. This production level involves the movement of some 60 million tonnes of waste and coal each year.The rehabilitation programme at Hunter Valley Mine has been developed to provide a combination of pasture, based on improved pasture species and timber belts to enhance the visual characteristics of the rehabilitated landform, whilst creating amenity in the form of shade for livestock.The operational philosophy for the rehabilitation programme is that of progressive rehabilitation. The best time to undertake rehabilitation is now.' As a result, planning for the rehabilitation programme is continuous, so that all site works are completed in time for vegetation establishment during the critical periods each year.

Jan 1, 1992

Increasingly, mineral operations need to manage water as a key business asset. Managing water solely as an environmental issue leaves a business exposed to social, cultural and economic risks associated with water. Adopting a company-wide strategic approach, which takes account of the true value of water will provide businesses with opportunities and risk protection. Rio Tinto has recognised the business imperative for water stewardship and has responded by producing the Rio Tinto Water Strategy. This strategy commits the company to managing water assets in a responsible manner, taking account of environmental, social and economic values. To incorporate the true value of water in site decision making, a new set of tools is required at the operational level. A key part of the strategy focuses on developing a framework to value water based on case study examples from around the Group. This paper presents progress on the companyÆs experiences in developing and implementing the water strategy.

Jan 1, 2006

Mount Isa Mines Limited commissioned the Heavy Medium Plant in August 1982. The first processing stage using Mogensen Sizer 2056 dry screens, experienced unresolvable cloth blinding problems in attempting to separate fine, damp Lead/Zinc ore at 1.7 mm. A large proportion of the fines incorrectly reported to oversize and hence to the wet preparation screens. This wet preparation screen overloading produced multiple operating and maintenance problems. The plant configuration precluded retrofitting any alternative proprietary screen. An internal Mount Isa Mines research and development programme was established to design and build a screen to achieve the required per- formance within the site constraints. The resulting ISA SIZER screen has exceeded metallurgical performance expectations. A `clean sheet' approach to the design also permitted elimination of maintenance difficulties experienced with the Mogensen Sizer. Four `production model' ISA SIZERS were installed in February 1988. The ISA SIZER screen, now fully developed is available commercially and will satisfy many screening plant requirements.

Jan 1, 1988

Synthetic and commercial activated carbons are characterised for several chemical and physical properties. A range of techniques is used to establish correlations between physicochemical parameters and gold- adsorption activities. The most important parameter in the carbon activation process for a product with a high gold-adsorption activity is the activation temperature. High activation temperatures yield products with large micropore volumes which provides sites that are ideal in size for adsorption. The surface area of an activated carbon is not necessarily a good measure of its adsorption activity. Surface oxygen-containing functional groups are identified by Fourier transform infrared spectrophotometry to be comprised mainly of ethers and hydroxyls. These functional groups line the edges of the micropores imparting a polar character to the pore and aid in the solvation of the adsorbate. Oxidants such as nitric acid result in a proliferation of surface carboxyl groups. resulting in a negatively- charged surface that is not conducive to the adsorption of gold.

Jan 1, 1993

By R Trueman

An improved ability to predict dilution for narrow vein deposits enables more accurate economic comparisons between mechanised longhole stoping and other narrow vein mining methods, as well as reducing uncertainty surrounding dilution estimates for deposits at the prefeasibility/ feasibility stage. This paper proposes narrow vein dilution prediction and minimisation strategies for both greenfield sites and operating mines, respectively. The narrow vein dilution method (NVD method) is a tool for more accurately predicting longhole narrow vein dilution. The method is based on a new concept called benchmark stoping width. Benchmark stoping width is based on probabilistic analysis of overbreak distributions from a typical longhole narrow vein mine. The premise for the NVD method is that dilution associated with longhole stoping can be predicted using the benchmark stoping width. In addition to dilution prediction, the NVD method also includes strategies for narrow vein dilution minimisation generally, including; filling, cablebolting, stress relaxation, extraction sequencing and blast overbreak.

Jan 1, 2008

By A G. Pavlides, B L. Weekes

The Sepon Copper Project is located in the Savannakhet Province of Laos PDR and is operated by Lane Xang Minerals Ltd (LXML). An Ausenco - Bateman Engineering joint venture, the Khanong Development Group (KDG) managed engineering, procurement and construction of the project. The plant was fully commissioned in March 2005, two weeks ahead of schedule. The plant is designed to produce 60 000 tpa of cathode copper. The process flow sheet includes a pressure oxidation (POX) circuit that leaches pyrite flotation concentrate to generate ferric ions and sulfuric acid for use in atmospheric leaching of a predominantly chalcocite ore. The process is unique in that the chemistry in the autoclave is forced to produce a basic ferric sulfate precipitate for downstream recovery of ferric iron. This paper describes the design, construction and commissioning of the pressure oxidation circuit. The challenges imposed on construction and commissioning due to the remote location of the site, landlocked status and underdeveloped infrastructure in Laos are highlighted.

Jan 1, 2005

By Murray G

This paper outlines the processes involved in acid generation from sulphides and the key factors in identifying and predicting time dependent changes in the nature of acid mine drainage (AMD). The initial characteristics of mine water; whether drainage from exposed mining faces, runoff and seepage from waste dumps or seepage from process tailings; do not necessarily reflect the long term potential for AMD. The ultimate quality of mine drainage is a function of the interaction of many chemical, physical, biological and engineering (operational) factors. Techniques are available that can predict the qualitative nature of acid generation and mine drainage quality but accurate quantitative predictions are essentially impossible at the present time. As more and more mining operations exploit sulphide ore, the AMD and acid waste issue will become a. far greater concern. The significance of time dependent factors in the production of acid mine drainage-.is not just restricted to particuL.ar mine sites but needs to be recognised by the mining industry as a whole.

Jan 1, 1988

The planning, design and construction of a service tunnel, under a major arterial road between two hospitals are described. The multiple uses of the tunnel combine to provide a favourable cost-benefit ratio for the tunnel as part of a rationalisation of services between hospitals. The driven tunnel provides economic, program and approval advantages over that of a cut and cover construction. The cross sectional shape of the tunnel was determined during feasibility studies by the degree of weathering of the Silurian mud- stones, the shallow cover and the proposed excavation equipment as well as the functional requirements. The site investigations covering geotechnical, building, noise and level surveys provided input to the design documentation and construction phases. Monitoring of settlement levels and primary support stresses during early construction stages confirmed the adequacy of the proposed tunnelling methods and support to be used adjacent to the major building foundations. The 140 metre long tunnel was success- fully completed in April 1980 at a cost of $650,000.

Jan 1, 1981

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

By De Broglio R

The Mae Moh coal deposit was discovered some 60 years ago by villagers who noticed spontaneous combustion of coal outcrops. The first production began in the 1950's to fuel a fertilizer plant and a 12.5MW power station. During the period 1976 to 1979, three 75MW power station units were constructed on site. These have a total daily coal consumption of some 5000 tonnes and are served by a stockyard of approximately 60 000 tonnes total capacity. Stacked coal is reclaimed by means of a front end loader onto reclaim conveyors. During the years 1983 to 1986 four 150MW power station units were constructed east of the eastern seam subcrop, sons 2 km from the original power station complex. These have a daily coal consumption of nearly 12000 tonnes and are served by a stockyard of total capacity 270000 tonnes, equipped with two stackers and two bucket-wheel reclaimers for a totally mechanised system.

Jan 1, 1986

By Marois R, Hauff P, Kowalyczk P, Lipton G, Bedell R, Neville R, Edmundo G, Ehling M, Kern R

The Canada Centre for Remote Sensing (CCRS) has developed an airborne sensor, the SWIR Full Spectrum Imager (SFSI) which detects in the Short Wave Infrared range of the solar spectrum from 1220 to 2420nm. In June of 1995, a demonstration flight was undertaken in the state of Nevada with the support of the companies listed above. The focus of the flight was to collect image data over well known mineral deposits with the objective of evaluating the applicability of this sensor to alteration mineral mapping. Some of the Nevada sites chosen include Cuprite and Goldfield, volcanic hosted acid sulfate systems; Yerington, a structurally complex porphyry copper deposit; and Virginia City, a Quartz- Sericite-Pyrite vein system with advanced argillic pods. Ground spectral data was collected with the PIMA-II spectrometer. Solar reflectance calibration was done by Desert Research Institute personnel at Virginia City and Cuprite. This paper will discuss the configuration of the sensor and present image and ground data for Goldfield and Virginia City.

Jan 1, 1995