Search Documents

A biological column leach testwork program was undertaken on a chalcocite ore. Three tests were conducted in all, using 65 in x 100 mm columns in three sections. The tests were started with varying acid strengths and inoculated with bacterial solutions from previous column testwork. The leaching of Cu was found to occur in three stages. These stages consisted of direct acid leaching, bacterial oxidation and ferric iron leaching. These leaching stages can most easily he described through the examination of not only Cu dissolution but also Fe dissolution and its subsequent oxidation and precipitation. The p11 of the system was found to he critical in establishing and maintaining the bacterial leaching system. The oxidation potential was seen to he influenced by the leaching system as the oxidation states altered. Test variables such as, 02, COz, and temperature were all found to influence the system. Final copper recoveries were in excess of 90 per cent in each column test over a leach time ranging from 211 to 328 days. Given similar leach conditions are applied, the application of this technology to site is expected to give comparable results.

Jan 1, 1994

By G Huggins

Excavation in underground jointed rock masses creates cavities into which the surrounding rock mass deforms. Deformations, besides intact rock deformation, include mechanistic deformations such as slip and rotation. In this paper deformational moduli were measured for prototype and blocky (jointed) models using elastic analogue methods for stopes from MIM LimitedÆs Lead Mine. The blocks for the models were defined in terms of the prototypeÆs joint sets, their spatial separations, orientations and average friction characteristics. From dimensional analyses, a relationship between prototype and model deformations was used to predict stope mid-span deformations. The results of this physical modelling work, conducted in the 1970s, motivated an investigation into the electro-treatment of tailings backfill to achieve improved strength and stiffness characteristics. Tailings backfill containing fines and having a high clay content can be electrically dewatered, and at times grouted, cemented, ion exchanged or agglutinated, to achieve relatively high magnitudes of strength and stiffness. These treated tailings stiffnesses can reduce the deformation magnitudes within a rock mass and, in doing so, reduce problems encountered in mine pillar extraction. The application of these tailings modification techniques is examined in relation to the elastic analogue methods.

Jan 1, 1998

By J Rowland, B Belle, M Webber

The Australian underground coal industry has experienced substantial improvements in longwall productivity and, as such, the methods of providing a safe and productive mine environment have needed to evolve and develop. Whilst the primary method of controlling atmospheric conditions is by airflow it has become impracticable or impossible for the majority of Australian longwall mines to contend with all environmental hazards with primary ventilation alone.If the ventilation circuit cannot provide a safe and productive mine environment at an acceptable cost and circuit duty then supplementary controls are required. Examples include pre-gas drainage, post-gas drainage, gas utilisation, refrigeration and innovative dust control systems. Of the 21 longwall operations surveyed in Australia, there were 13 in New South Wales and eight in Queensland.This study represents a timely opportunity for the industry to examine the primary and supplementary ventilation systems implemented in Australian longwall mines and to discuss how to equip the industry to successfully face the future of underground longwall ventilation management in Australia.CITATION:Webber, M, Belle, B and Rowland, J, 2017. Australian longwall ventilation systems, in Proceedings Australian Mine Vent Conference 2017, pp 301–308 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

Hilton Mine is located 20 km north of the city of Mount Isa and Isa Mine in far north west Queensland. The sealed road used by the 500 employees to commute from the city is part of the Barkly Highway linking Mt Isa to the Northern Territory.Although discovered in 1947, major underground development did not start until late-1982 and first cut-and-fill production in mid-1987. The J53 exploration shaft was sunk in 1970-73 and the main P49 shaft in 1973-75. Since January 1990, most of Hilton ore production has been treated in the Hilton Concentrator, and concentrates trucked in slurry tankers to Isa for smelting or shipping.

Jan 1, 1993

The need for ventilation around mine workings derives from the various gases found in mine atmospheres and CH4, the principal diluent is in quantity depending upon several factors. Several of these are seam thickness, depth of cover and working method and the French Regulations typify controls on coal mine ventilation. There are many factors affecting production of CH4, in addition to coal production, such as the geological setting of the working seam, the geometry of workings and the rates of advance. The possibilities of spontaneous combustion should not be overlooked. The complexity of high production modern colliery layouts is such that sometimes there maybe 200 airway branches. There are specific differences in ventilation networks between the mining methods of rooms and pillars, shortwalls and longwalls as affecting resistance losses, as well as necessary airflows and ventilating

Jan 1, 1983

The Tick Hill Gold Mine is situated approximately 110 kilometres south of Mount Isa, and 14 kilometres north of the township of The Monument. It was discovered in October 1989 by Mount Isa Mines Exploration in an area which had been targeted as high in potential for copper-gold mineralization.A mining lease application was made in March 1990. Mining, and the construction of the plant and infrastructure, began'in early August 1991 after the lease was granted on 20 June of that year. Commissioning of the plant began in December 1991, and the first gold was poured on site on 31 December 1991.The development of the underground mining operation commenced in January 1992 with the drilling of the ventilation shaft. The access decline was started in March of the same year, with the first ore produced from underground in August.

Jan 1, 1993

By Bhattacharyya AK

A two-dimensional finite element modelling technique is applied to predict the subsidence movements on a sloping ground surface above a completely mined panel. The modelling is carried out for the surface both directly and using a combination of an equivalent horizontal surface and a rays projection method and the result compared. The rays projection method provides the subsidence components on a sloping surface from the corresponding ones on an assumed equivalent horizontal surface through the point of mean elevation of the relevant part of the sloping surface. This method is used next to compare the subsidences, horizontal displacements and horizontal strains from the mining of a given panel at the surface for different inclinations. The results show that the magnitudes of the subsidence components are greater on the dip side of the slope from the point of the mean elevation, than the corresponding ones on the rise side and the asymmetry increases with the inclination of the surface. The findings are also compared with those of other research Workers.

Jan 1, 1992

Pillar mining methods at the Pasminco Mining Broken Hill Operations are not new. Since mining commenced on Pasminco's leases at the turn of the century virtually every pillar extraction method tried throughout the world has been used. Much of the remaining mineral resource in the Pasminco Broken Hill leases is contained in pillars.However, due to the on-going need for mechanisation with bulk mining methods, and the very peculiar physical circumstances surrounding the formation of these pillars, their exploitation requires the development of a virtually new method based on excavation technology not previously used in the Australian mining industry. Trials of the method are to take place at the southern operations during 1991.

Jan 1, 1992

By J Williams

The recent drought has highlighted the finite nature of AustraliaÆs divertible water resources. According to AustraliaÆs recently completed National Land and Water Resources Audit, development of water resources in southern Australia has reached or exceeded sustainable extraction limits. Similarly, 161 out of 538 groundwater management units are either totally allocated or already over allocated. Whilst mining only uses about three per cent of diverted water resources, water scarcity may be a major factor that determines whether potential mines can be developed in the future. Furthermore, the development of extraction and processing facilities that limit water use and maximise the re-use the waste water streams will be even more fundamental features of the mining industry in the 21st century than they are at present. There are encouraging examples where innovative water re-use technologies are significantly reducing the water used per unit of mined product. Whilst mining in the areas of Australia draining to the tropical seas may be less constrained by a current lack of water (60 per cent of divertible water resources drain into the Timor Sea, Gulf of Carpentaria and north east Coral Sea), it is highly probable that there will be increasing demand for these waters from the irrigation industry, whilst pressure will also be applied to ensure that environmental flows that benefit the coastal fishing and prawn industries are maintained. In the Great Artesian Basin, current research is demonstrating that the groundwaters are being recharged at rates considerably lower than current extraction. Whilst some other groundwater basins in arid and semi-arid Australia have currently untapped resources, these water are often relatively saline and/or may be intimately linked with key ecosystems in discharge areas. This paper presents an overview of the current state of our water resources and examines some of the key water use issues including allocation, use and reuse, environmental flows and competing demands on the resource that will ensure that water issues remain high on the policy agenda for mining, irrigation and other water users.

Jan 1, 2003

By M Chappell

This paper describes the design of the steel fibre reinforced precast concrete (SFRC) segmental lining for the intake and discharge tunnels for the Gold Coast desalination plant in Queensland. In addition, the key design requirements and design methods for the lining of these 2 km long, 2.8 m internal diameter tunnels, including structural, durability and maintenance requirements are discussed. Details of the segment configuration and erection process are presented along with information on the manufacture and trial testing of the concrete for the segments. The paper also gives a brief introduction to steel fibre reinforced concrete behaviour. Construction of the tunnels commenced in April 2007, and the authors believe this is the first application of this technology in Australia.

Jan 1, 2008

By K McCaffery, R P. Halomoan

Two column flotation cells have been installed as single-stage rougher cleaners at Batu Hijau. The objective was to provide additional residence time in the cleaner circuit to maintain maximum recovery during high mill throughput and high feed grade periods. Installation of the columns has allowed the relatively coarse, well-liberated rougher concentrate and the relatively fine, low-grade scavenger concentrate to be treated separately, improving metallurgical performance in the cleaner circuit. Plant results show that the columns produce a high-grade concentrate at an average stage copper recovery of approximately 80 per cent. There is also indication of increases in both overall plant copper recovery and final concentrate copper grade. In addition, the operability and stability of the cleaner circuit has greatly improved.

Jan 1, 2007

The underwater test is now being used routinely to characterise explosives and initiators. However, several outstanding issues regarding the role of confinement and the usefulness of the test results in predicting expected blasting performance require further elucidation. This paper reviews the underlying principles governing the test, and highlights its relative advantages and disadvantages in product development and applications. It deals with topics of energy release, energy partitioning, confinement and efficiency, supported by illustrative examples from tests with various products and geometries. The results are analysed in terms of both the detonation parameters measured and their extension to predicting blasting performance in the field. It is emphasised, that just as with other performance tests, the results and conclusions are only valid under the particular test conditions employed, and over-generalisation of these results can lead to erroneous conclusions.

Jan 1, 1999

By L C. P J Fonteneau, B Godel, E R. Ramanaidou

The Hamersley Province in Western Australia hosts large iron ore deposits. Each deposit displays various iron ore types that were defined on their metallurgical properties, especially in terms of porosity and mineralogy. Conventional porosity and mineralogy information on iron ore types are provided on 2D thin sections using automated image analysis with scanning electron microscopy (SEM)-based techniques combined with chemical analyses. However these techniques cannot accurately quantify the 3D porosity. High-resolution X-ray computed tomography (HRXCT) is a non-destructive technique providing a 3D image of the sample with a resolution close to 0.5 - 0.7 ¦m for samples size of up to few centimetres in length. 3D image analysis using customised algorithms now provide accurate quantitative porosity and mineralogy of iron ore types.CITATION:Fonteneau, L C P J, Godel, B and Ramanaidou, E R, 2013. Application of high-resolution x-ray computed tomography to iron ore characterisation, in Proceedings Iron Ore 2013 , pp 243-250 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

Underground mining of the ore below the West Lyell open cut commenced in 1972 with the 10 Series stopes above rail haulage level. The third lift of stoping (30 Series) com- menced this year, and access to the 40 Series stopes is being developed. The method uses transverse open stopes with subsequent mass blasting of the rib and crown pillars and consequently there is sub- sidence and caving of the old open cut area above.

Jan 1, 1982

The Porgera mine and treatment plant are located in the Enga Province of Papua New Guinea. Gold in the Porgera deposit is found free and in association with the primary sulphide mineral pyrite. The refractory nature of the gold in the pyrite r

Jan 1, 1997

The Copper Concentrator at Mount Isa Mines Limited treats approximately 6 Mt of chalcopyrite ore annually. The ore is currently sourced from the 1100 and 3000 orebodies at Mount Isa. Chalcopyrite is the only significant copper bearing mineral, with pyrite, quartz and dolomite being major gangue minerals. Ore is typically 10% chalcopyrite, 11% iron sulphides and 79% non-sulphide gangue. Copper ore is treated through two autogenous mills, two ball mills and a flotation circuit. The autogenous mills replaced a crushing plant, two rod mills and two primary ball mills during 1991. For routine analysis of concentrator performance, composite samples of mill feed, final concentrate and tailings are generated every 4 week period. All samples are sized and size fractions are assayed. Recovery of mineral species to the concentrate are then calculated for each size fraction. Sometimes liberation analysis was also performed by QEM*SEM (Quantitative Evaluation of Material by Scanning Electron Microscope).

Jan 1, 1990

A computer programming language known as GPSS is described and possible applications for the mining engineer are presented. The language is continually being upgraded with improved versions appearing about every three years. The tremendous power of the language is considered by comparing it with standard engineering programming languages, such as Fortran or Basic. Sample problems that can be solved using the language are indicated. The advantages and disadvantages of the languages are also discussed.

Jan 1, 1987

By T J. Howard

At BHP Billiton Iron Ore operations, run of mine ore from the several Newman Joint Venture (NJV) mines is railed in 12 kt rakes to Port Hedland. Rakes are processed sequentially, with the lump and fines components from each rake sampled after crushing and screening. The grade of ore from the individual mines varies around consistently different means. Although a discrete sample is attributed to each rake, the sample contains some material from the following and/or the preceding rakes due to dilution by ore from the neighbouring rakes during the dumping, screening and crushing processes. Individual rake grades at the port are therefore biased according to the mine sources of adjacently processed rakes. Dilution does not affect the grade of the overall NJV product or the accuracy of port stockpile grades; however, it does limit the ability to use port rake grades to review the quality performance of individual mines and provide meaningful lump-fines algorithms and port to mine biases for individual mines, information that is useful when scheduling ore for mining. A non-linear regression model has been used to estimate the average dilution from the preceding and following rakes. It has been shown that the lump and fines samples for 12 kt rakes are each diluted within the Port process with about 8.3 per cent of the sample coming from the preceding rake and about 3.6 per cent from the following rake. This can bias the reported rake grade by up to one per cent iron. The results of this analysis have been incorporated into the daily grade scheduling system to provide more accurate individual mine grade data and consequently better decision making.

Jan 1, 2007

Coal washery wastes comprise tailings, finer than 0.5 to 0.1 mm depending on the sophistication of the washery, and coarse reject, typically finer than 50 mm. Subaerial disposal of coal tailings slurry at about 30 per cent solids by mass results in the formation of a delta with an average slope of about 1 in 100, representing one extreme. The ravelling of coarse reject on loose-dumping, results in an angle of repose slope with an angle of about 37o (1 in 1.3), representing the other extreme. The pumped co-disposal of coal tailings and coarse reject results in the formation of an upper delta with an average slope of about to one in ten, between the two extremes. The depositional behaviour of these three waste streams is discussed and compared in this paper. The important depositional and material parameters, and a theoretical description of the processes involved, are also presented. Comparisons are made between the depositional behaviour of the various coal washery waste streams, and natural depositional systems, such as rivers, alluvial fans, and scree slopes.

Jan 1, 1998

By D J Williams

Coal washery wastes comprise tailings, finer than 0.5 to 0.1 inn depending on the sophistication of the washery, and coarse reject, typically finer than 50 mm. Subaerial disposal of coal tailings slurry at about 30 per cent solids by mass results in the formation of a delta with an average slope of about 1 in 100, representing one extreme. The ravelling of coarse reject on loose-dumping, results in an angle of repose slope with an angle of about 37" (1 in 1.3), representing the other extreme. The pumped co-disposal of coal tailings and coarse reject results in the formation of an upper delta with an average slope of about to one in ten, between the two extremes. The depositional behaviour of these three waste streams is discussed and compared in this paper. The important depositional and material parameters, and a theoretical description of the processes involved, are also presented. Comparisons are made between the depositional behaviour of the various coal washery waste streams, and natural depositional systems, such as rivers, alluvial fans, and scree slopes.

Jan 1, 1998