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AustraliaÆs record-breaking drought, efforts towards environmental best practice and the current commodities boom is demanding water use and reuse as never before. Mining practices, processing, the remote communities and support industries require vast amounts of specific quality water. Sustainability of water use has been a key factor in mine development, expansion of existing operations and increasing profitability of processes involving water. Developments in water treatment technology have enabled the use of a range of processes to produce this water reliably at ever decreasing costs. This increasing acceptance of new technologies has seen seawater desalination, recycling of plant wastewater streams, municipal wastewater reuse and others to become commonplace. Processes including seawater and groundwater reverse osmosis (RO), low pH RO, thermal desalination, high rate clarification, brine water treatment, ion exchange and other advanced treatment technologies are now used as part of mining operations. This paper surveys the trends in water treatment for the mining industry both in Australia and internationally with a review of technologies and case studies of operating plants. The key technologies are explained with an emphasis on the specific requirements for mining operations û unusual raw water, process and operations limitations, environmental concerns, as well as harsh climate. Case study information from several mining operations is included.

Jan 1, 2006

By Hyde L. J

Blasting is one of the available technologies to be employed in underground excavation systems. In many instances it can be the only technology which is suitable. The recent moves towards more mechanised working systems is resulting in a reduced awareness of new blasting practices and technologies on the part of many excavation engineers. Recent developments in blasting systems can be utilised to significantly improve operating efficiency, reduce total cycle times, better comply with regional environmental constraints and reduce the total cost of underground excavation. Blasting is and will remain, a very adaptable and exciting alternative which is far from boring.

Jan 1, 1987

The comparatively low winter rainfall, exposure to heavy salt laden coastal winds, and the consequent high evaporation rate, are important considerations in the rehabilitation of the Maslins Beach Sand Pit. The deficit of rainfall over evaporation is assessed at 1085 mm per annum. Such a coastal environment complicates the establishment of plants. The endemic flora found on the Sand Pit environs is mainly low wind-planed shrubs and mat plants. The dunes near the coast support an association dominated by Atriplex cinerea, Spinifex hirsutus, Scirpus nodosus, and Olearia axillaris. The coastal cliffs carry a more diverse vegetation dominated by Beyeria lechenaultii and Eutaxia microphylla. Overburden is used to develop a new landscape to screen operations, batter final faces, and cover rubbish at the nearby Council dump. The early overburden dumps were built with little regard for stability, but the more recent practice of using scrapers has resulted in more stable dumps. The erosion problems created by poor compaction have been controlled by contour banks, diversion drains, bitumen lined run-off drains, and hay mulching.

Jan 1, 1976

By Bourne R. W, Smith T

This paper presents initial findings of a project examining novel processes for the treatment of refractory sulphidic gold concentrates. Non-oxidative roasting of such concentrates for 12 hours at 750¦C resulted in the finely disseminated gold agglomerating to form discrete grains. The pyrite and arsenopyrite decomposed to form pyrrhotite, whilst the labile sulphur and arsenic driven off was collected on a condenser as a mixture of elemental sulphur, metallic arsenic and various arseneous sulphide compounds. As a result, the cyanide solubility of the gold contained in sulphidic refractory gold concentrate from the Emperor mine in Fiji improved from 54.5 per cent to 98.4 per cent; from the Fimiston mine in WA (65.2 per cent to 96.6 per cent), from the Windarra mine in WA (69.6 per cent to 91.3 per cent), from the Harbor Lights mine in WA (20.4 per cent to 60.7 per cent), and from the Wiluna mine in WA (12.6 per cent to 28.0 per cent). The non-oxidative roasting conditions have not been optimised for each of these minerals. Subjecting the non-oxidatively roasted minerals to mild oxidative acidic iron sulphate pressure leaching (with typical temperature of 100¦C and typical oxygen overpressure of 500 kPa) to remove iron and so further liberate finely disseminated gold, resulted in the cyanide solubility of the gold exceeding 96 per cent for each of these five concentrate types (including those from Harbor Lights and Wiluna). Thiourea leaching of the sulphur-rich residues under acidic conditions resulted in remarkably high gold extractions being achieved. These novel processing options need to be optimised, and their economic viability established.

Jan 1, 1991

By Raczej I, Defant M

Pre-Miocene igneous rocks from the Phili pine island arc are characterised by 87Sr/86Sr and 143Nd/144Nd ratios typical for intra-oceanic island arcs where sediment involvement in the magma genesis was minor. Lead isotopic ratios are similar to Indian Ocean MORB (Mukasa et al., 1986a,b). Pliocene to recent volcanics, however, have more radiogenic Sr and Pb and less radiogenic Nd, except for the volcanics of the Bicol Arc, which have similar isotopic signatures as the Pre-Miocene rocks. We suggest that Pre-Miocene magmas and Bicol-Arc magmas have been generated in response to the subduction of the Philippine Sea Plate, their isotopic characteristics reflecting the composition of Philippine Sea crust. The Bataan arc magmas may reflect the larger amounts of sediments available for subduction in the South China Sea, while magmas of the Mindoro Arc, which are characterised by the most radiogenic Sr and least radiogenic Nd, may have been contaminated by slivers of the Mindoro-North Palawan terrane, which have been carried down to mantle depths after the collision of this terrane and the Philippine arc in Miocene (McCabe et al., 1982). This interpretation implies that Nd (and by inference other REE) can migrate from the subducted slab to the mantle wedge. Thus, variable Nd-isotopic ratios in island arc magmas (e.g. Sunda, Lesser Antillas) may not he a primary feature of the mantle wedge but a consequence of the release of Nd from the subducted slab.

Jan 1, 1987

The investigation of Noapara glass sand deposit in Sylhet district of Bangladesh is performed to beneficiate the sand for the manufacture of colourless glass. For the ease and efficient removal of the colour bearing impurities, the physical and mineralogical investigations of the sand deposits is carried out first. The sand is then treated with the standard beneficiation procedures to reduce the impurity level to an acceptable level. It is found that the Noapara glass sands are of medium grained and moderately sorted. They contain 0.15 - 0.30 per cent Fe2O3 and 0.001 -0.008 per cent Cr2O3 as major colour bearing impurities. The heavy mineral fractions containing most of the impurities can be grouped into five types of associations:stable or ubiquitous minerals (tourmaline, zircon, rutile); metamorphic species (staurolite, kyanite); amphibole minerals (hornblende, tremolite); the micas (muscovite, biotite); and discrete minerals (magnetite, ilmenite, etc). It is also seen that, the use of mechanical separation process in combination with water washing, attrition, and magnetic separation can remove a maximum of only 70 per cent of total Fe2O3 present in the deposits. This is insufficient to produce the specified grade of sand to manufacture colourless glass. Among the various chemical treatment processes used, sodium dithionite method is found to be the most effective, although the discrete minerals are not removed. Using the specific reagent group during froth flotation, the iron and chromium contents are reduced to 0.03 and 0.001 per cent respectively which are very near to the specified colourless glass composition.

Jan 1, 2000

By Isokangas T. A

With some two-thirds of the production exported, coal mining prac- tices of the last few years in Australia have been much influenced by the decline in the price received. It became essential to improve efficiency and rationalise operations. Trends in underground practice vary. On the one hand many additional longwalls have been installed and most recently the results achieved by them have shown a significant up-turn; this may be correlated more with increases in equipment capacity than with utilisation which has altered little during the past six years. Varied constraints remain affecting cur- rent and future longwall operations. On the other hand a number of mines have been closed whilst others have sought to improve results by various installations including miniwalls, shortwalls, and use of continuous haulage and mobile breaker line sup- ports. All mines continue to review working practices.

Jan 1, 1988

Anodic stripping voltammetry is an analytical technique which has established some popularity for trace analysis of metals because of its sensitivity, selectivity and capability for simultaneous analysis of some elements. The technique can be readily adapted for field use because of its relative simplicity and low power requirements. This paper describes a relatively new instrument, the Portable Digital Voltammeter, developed by CSIRO, which utilises the glassy carbon electrode in a novel cell design and provides parts per billion (ug/L) sensitivity in an instrument which can be field operated. Ten elements, Zn, Cd, Tl, Pb, Cu, Sb, Bi, Hg, As and Au can be routinely analysed. Many of these elements are of interest to the mining industry, and to exploration geochemistry in particular. Case histories where the instrument has been successfully employed for stream and stream sediment analysis of Cu and Pb, for soil surveys of Cu and Au, and for Au in stream sediments and drill chips indicate there are advantages in having on-site data, during Exploration.

Jan 1, 1987

Various factors influence the exploration geologist or geochemist in his choice of.an analytical method for gold and other elements which may help him find the elusive gold deposit. One of the first decisions the geologist must make is the nature of sample media to collect for his survey. Needless to say there are many media available depending on the situation. These include rocks, soils, heavy mineral concentrates (from overburden drilling and panned concentrates), humus, vegetation, water, lake bottom sediments, stream sediments, etc. The choice of the sample media will depend to a large degree on the state of development of the particular project from grassroots to mine feasibility. The nature of the geological information required will affect which media and which analytical technique should be chosen for the analysis. Valid sampling from the initial sample collection, preparation and subsampling aspects may also help to determine which analytical procedure is best. Cost and turnaround time are of prime. importance to the explorationist, as it should be, however, these aspects should not be detached from receiving accurate and reliable results.

Jan 1, 1987

Drill and blast operations account for 12 - 15 per cent of total mining costs. This paper looks at a comparison between electronic detonators and non-electric detonators, focusing on the cost benefits associated with the high precision of the timing sequences of electronic detonators. An analysis of the total mining costs was made on two main case studies; one on a quarry in South Australia (Martin, 2007) and the other on a project undertaken at Sunrise Dam (Vaughan et al, 2007). The criteria used in the analysis included; the resulting fragmentation, a vibration analysis, crusher throughput and productivity analysis such as excavator cycle times, dig rates of the excavator and bucket fill factor. The results indicate that there were consistent production improvements and hence reductions in total mining costs attributed to the use of electric detonators. An increase in the degree of fragmentation gives lower crushing costs as more material passes through as undersize. This reduces truck delay time at the crusher, which in turn gives higher truck and shovels productivity as well as higher dig rates for the excavators.

Jan 1, 2008

Although the flotation cell has been under continuous development over the past 80 years, an understanding of the precise roles of a cell in produc- ing the flotation result had evolved slowly. In fact, detailed studies of cell dynamics began only in the 1940s when flotation practice had almost reached the half-century mark. The earliest generalizations related cell capacity to power intensity (hp/vol- ume) (Rose, 1946), and specific operating features such as aeration and power ' consumption to impeller submergence and operating speed (Read, 1933). In the 1950s hydrodynamic characterization of cells through power coefficients and air flow numbers began (Arbiter and Harris, 1961) and has continued to the present, with increasing industrial use of these concepts (Degner, 1982; Degner and Treweek, 1976). Liquid flow measurements in Wemco cells (Degner, 1982) made liquid flow numbers and turnover frequencies available for more complete under- standing of cell dynamics. The present overview of flotation technology is a critique of cell design. The cell process represents the interactions between cell dynam- ics, cell geometry, and ores, with the latter prepared for that interaction through size reduction and reagent treatment. While previous invest- igations of flotation cells have accepted all cell designs uncrit- ically, the present study considers the physical process components that an effective cell must provide, and then compares a limited number of

Jan 1, 1984

By Boontanjai C, Boyapati ER

Reagents used for batch flotation tests were Aeroxanthate-343 & 350, Dow Z-6, & reagent-4037 (from Benambra) as copper collectors; Na2SiO3 & Na2S2O3as gangue depressants; lime & HCl as pH regulators; and pine oil & MIBC (methyl isobutyl carbinol) as flotation frothers. A Denver Sub A flotation cell of capacity 250 gms was used for the batch flotation experiments. Atomic absorption spectrophotometer was used for copper assays and microscopy for selectivity and liberation studies. Melbourne tap water was used throughout the experiments. Unless otherwise stated, the following parameters apply to the flotation experiments: flotation impeller speed - 1300 rpm, pulp density during flotation- 22%, reagents addition - in 4 stages, total conditioning time for collectors - 8 minutes, total flotation time- 9 minutes. A variable quantity of copper mineral collector according to the test in question was added, then conditioned the pulp for 2 minutes. The froth was removed by hand, scraping the full length of the cell at constant depth every 10 seconds. No frother is required for this copper tailing flotation. Four concentrates were collected after addition of collector and conditioning at 2,4,6 and 9 minutes. The pulp volume was maintained at a constant level to yield a constant froth depth.

Jan 1, 1990

A key premise to this paper is that most people involved in the design and implementation of drilling and blasting operations could benefit from a greater understanding of the geological materials, deposits and landforms they are dealing with. The second key ingredient for successful blasting is the concept of blasting objective. Mine operators and blasting contractors must be clear on what drives their costs (blasting leverage) and should formulate blasting objectives and operational targets which help in this regard. Many operators ignore geology descriptors and features apart from the name of the rock and start crudely quantifying the rock mass properties in terms of uniaxial compressive strength, or even worse still as hard or soft. This occurs too early in the design process and not much attention is paid to the geological materials, geological structures and the characteristics of the deposit they intend to excavate. In effect the rock type name and the strength descriptor become the site geology. Furthermore many blasting operators do not formalise their blasting objective, do not set operational targets and do not measure results to the degree required for continuous improvement. In this paper a number of civil, surface mine and underground mine blasting applications are tabulated in terms of typical blasting objectives and common geological materials. A good description of geological materials can convey a lot of useful information for blasting operators if they are able to accommodate this knowledge. In addition a clear statement of the blasting objective and associated operational targets will maximise the likelihood of achieving blast-driven downstream productivity improvements. The æStarting at Both EndsÆ combination is deemed extremely useful for any continuous improvement blasting program.

Jan 1, 1999

The maintenance system for underground mobile equipment at Cobar Mines Pty. Ltd. has been modified from that originally planned as a result of experience gained in operating the equipment.Downtime due to breakdowns has been reduced by improvement of vehicle servicing and overhaul procedures.Frequency of breakdowns can be reduced by training operating and maintenance personnel to a high standard, ensuring adequate numbers of tradesmen and supervisors, good maintenance facilities and communications, a well designed mine layout, and a comprehensive stock of spare parts.A maintenance and downtime summary is compiled for each four-week operating period and this is useful in highlighting particular problems where corrective action must be taken.

Jan 1, 1969

By M Kizil

Mining Engineering Degree programs have traditionally had a practical emphasis and have been highly vocational in nature. However, over the years, there has been an increasing attention to the more scientific aspects of the discipline. More recently, the professional institutions, the industry and the community at large have placed increasing emphasis on the broader aspects of the professions: management, finance, humanity, environment and social issues. Notwithstanding this, there has been a continuing emphasis on the practicalities, and most Mining Engineering programs are still strongly vocational in nature. But employers of new graduates complain about the graduatesÆ lack of practicality and readiness for employment æat the sharp endÆ on the mine site.This paper briefly describes some of the more recent developments in the Mining Engineering Degree program at the University of Queensland that attempt to address the problem. Particular attention is paid to alternative learning programs, including applications of virtual reality, practical experience at the University Experimental Mine (UQEM), and the Undergraduate Site Learning Program (USLP).

Jan 1, 2002

By White B

A novel approach is suggested for the solution of planning and development problems in the coal, mining industry. The formation of coal measures depends to a significant extent on sequential geological processes and events which are probably best defined in a "system of processes and responses." The great number of variables in such a system is a characteristic feature of geological environments. Research work over the past two decades, in particular, has successfully established analytical procedures for the identification and definition of relevant and irrelevant variables for mining developments in specific geological situations. Such situations are typifiable within the regional geological setting of coal deposits. Scale gaps can be bridged by reliance on common symmetrical attributes and pervasive geometric features. Depositional processes and their resulting attributes are responsible for the development of mechanically significant rockmass "defects" and anisotropies; such features have to be identified and assessed for the selection of colliery design criteria. It is suggested that the procedural frame- work of systems engineering analysis is a most appropriate tool for the assessment of those geological features that can influence the mechanical behaviour of the "floor-seam-roof" system in "high technology" mining operations of the future. It is anticipated that the overall emphasis of future mining systems will be toward the use of larger scale more highly productive methods and machines, with higher capital outlay but

Jan 1, 1987

By D J. Cronin

Alcoa World Alumina AustraliaÆs Huntly and Willowdale bauxite mines are located in the Darling Range of South Western Australia, which places their operations within PerthÆs surface water supply catchments. These catchments supply Perth with its highest quality drinking water. With the decreasing rainfall trend of recent years catchment yields to water supply reservoirs have reduced to such an extent that water use restrictions were necessary in Perth for 2001, 2002 and 2003. Protection of catchment water quality and water use conservation are crucial issues for AlcoaÆs operations within the Darling Range. Alcoa has been conducting bauxite mining activities in water supply catchments since the mid-1960s. During that time Alcoa has worked closely with the relevant State Government water and environmental agencies to ensure that its operations do not adversely impact catchment water yield and water quality. Monitoring and research have shown that Alcoa has the necessary environmental management systems in place to ensure it can continue to operate in a sustainable manner within water supply catchments. AlcoaÆs mines reduced the volume of water taken from public water supply catchments by 24 per cent in 2002, compared with 2000. This success has had an added benefit; Alcoa does not need to develop a new water source for its Huntly Mine. The conservation measures implemented to reduce water use include: increasing water recycling, using chemical additives for haul road dust suppression, conducting water audits, reducing water demand, monitoring water use, promoting water use targets and training staff in water conservation.

Jan 1, 2003

By A Richmond

"In some lode-style gold deposits the geological (lithological) uncertainty may have similar economic significance as the grade uncertainty. In the absence of precise knowledge of the deposit geology, geological models of these types of deposits that are used to constrain spatially the estimated (or simulated) grade values may influence significantly the contained metal. Methods for assessing geological uncertainty quantitatively are rarely considered due to their perceived inability to consider exhaustive geological interpretations, and resulting models that often appear geologically unrealistic. Furthermore, should the lodes have been subjected to folding, or where the mineralisation continuity does not follow a planar orientation along strike or down dip, standard methods of variography and interpolation using linear vectors in space often do not provide a good representation of continuity. An alternative approach is to relate spatial samples from adjacent drill holes using an unfolding plane.The paper demonstrates conditional simulation of the geometry and gold grades of a folded lode-style deposit where:simulation of lode geometry considers explicitly the geologistÆs interpretation, andsimulation of gold grade values that consider explicitly the folded nature of the lodes.The results are contrasted to the traditional approach of linear vectors in real space for a single lode interpretation.CITATION:Richmond, A, 2012. Conditional simulation of a folded lode-style gold deposit, in Proceedings Narrow Vein Mining 2012 , pp 149-154 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 26, 2012

By G Brewster

The Eagle on the Hill tunnels form part of an upgrade of Mt Barker Road, 15 km to the southeast of Adelaide. The upgrade significantly improves safety and reduces delays on this major road, which winds steeply through mountainous terrain. The twin tunnels each spanning 15 metres run in parallel for a length of 480 metres. The tunnels are excavated in slightly weathered high strength slates and very high strength quartzites of the Saddleworth Formation on the western margin of the Mount Lofty Ranges. Steeply dipping slate cleavages and the high fracture ratio result in many slope stability problems in the project area. The level of geotechnical investigation undertaken prior to the calling of tenders for the project was extensive. This included the excavation of a pilot tunnel along one of the tunnel alignments, which allowed accurate mapping and rating of the rock, resulting in an increased level of confidence during the tender process. One of the features of the winning alternative tender design was the use of canopy tubes, flexible steel ribs and shotcrete to replace up to 40 metres of deep portal cuts in unstable rock with driven tunnels. Slope stability issues were overcome with the use of rock dowels and shotcrete. The support concept allowed the safe driving of the tunnel portals with as little as two metres of overburden. The design incorporated lining drainage and criteria for fireproofing based on European experience to ensure the ability of the tunnels to remain stable in the case of a severe fire incident. The support design allowed for maximum flexibility with a range of support types able to deal with the varying ground conditions. Design development and support refinement continued throughout the tunnel construction phase with close liaison between the designer and the constructor. Monitoring and review of feedback from the construction site by the Sydney based design team was easily achieved by means of electronic transfer of photographic and survey information, telephone and fax communication and regular site visits. The contractor for this project is Macmahon Concrete Constructions Joint Venture (MCCJV) and the designer is Connell Wagner. Excavation commenced in January 1998 with tunnel breakthrough having been achieved in early-August 1998 and mid-September 1998 respectively. Concrete lining construction is scheduled for completion in April 1999.

Jan 1, 1999

By Buizen M

An investigation into the mechanics of sub-surface deformation caused by caving of the extracted area behind retreating longwall faces has been completed by the Subsidence Engineering Section of the New South Wales (NSW) Department of Minerals and Energy. Changes in strata bulk permeability were also measured by standard packer tests undertaken before and after mining. The strata movement was measured by a multi-wire borehole instrumentation system consisting of mechanical anchors installed at different horizons in a borehole extending from the surface to the coal seam. The mechanical anchors were collected to suspended weights on the surface by stainless steel multi-strand wires. The movement of these weights was monitored as the longwall face approached and retreated past the borehole. The anchors did not move significantly until the face went past the borehole. For subcritical extraction geometry with the extraction width to mining depth ratio of 124, the caving zone extended to roughly 9 times the extracted seam thickness above the seam roof. Tensile strains within the overburden tended to be much more closely related to stratigraphy than to the proximity to the extracted seam roof. Larger tensile strains were associated with layers of sandstone, siltstone and conglomerate, whereas layers of mudstones, claystones and coal underwent much smaller strains indicating subsidence in blocks. A beller correlation was observed between pre-mining Rock Quality Designation and permeability than between rock type and permeability. This correlation was less evident in the post-mining core logs. There was an overall increase in bulk permeability after mining.

Jan 1, 1990