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The Archaeozoic Willyama Complex at Broken Hill has suffered several periods of deformation and metamorphism. New structural and petrological information together with that available from the literature gives a picture of the metamorphic evolution of the Barrier Ranges. Several epochs of metamorphism are recognized, and potassium-argon dating of minerals has been applied with limited success to the resolution of these epochs.INTRODUCTIONAdvancements in the mineral industry at Broken Hill over the past eighty years have been accompanied by a continual striving towards increased understanding of both the geological history of the Barrier Ranges and the environment of the Broken Hill ore deposits. However, although many detailed studies of selected localities and particular-aspects of Broken Hill geology have been carried out recently, the regional geology of the Barrier Ranges as a whole has received little attention from a petrological viewpoint since the pioneer investigations of Mawson (1912) and Browne (1922). There still remains a great need for regional surveys combining field studies of the habits, structures and outcrop relationships of the various rock types with laboratory investigations of their chemistry, mineralogy and microscopic ,fabrics. Recording observations arising from three brief visits to the Broken Hill area during 1959 and 1963 may stimulate further surveys.During one of these visits, the generosity of the Zinc Corporation Limited in providing field transport and geological guidance enabled the writer to collect material and study field relationships and appearance of the various rock types at numerous localities covering most of the Willyama outcrop. A complete study has not been conducted...

Jan 1, 1963

By A Hollweg, K H. Esbensen, M Lischka

Two new splitter designs for intercepting moving streams of matter are presented, the variable cross-stream splitter (vCSS) and the rotary stream splitter (RSS), which are intended for implementation in a fully automated modus. The vCSS facilitates obtaining up to three subsamples with different splitting ratios from automated laboratory flow paths, while the RSS divides the intercepted sample into 16 equal analytical aliquots. The splitters can process a wide range of dry, granular and free-flowing materials (<5 mm). The required weight for each subsample can be set without mechanical adjustments in the case of the vCSS. Typical applications are subsampling/splitting for X-ray fluorescence pelletisation (or fused beads) or splitting for average shift composite sampling or grain size analysis. The vCSS combines the advantages of riffle splitting (three user-defined subsample masses) with miniature bed blending and can accept up to 15 kg in total incoming sample mass. In practice, the automated vCSS can deal with unlimited ingoing mass fluxes, while the RSS is designed to operate at a user-defined fixed subsampling rate (1/16th in the tested version). Both splitters have the potential to be optimised and evaluated according to an application/user-defined total sampling error (TSE) + total analytical error (TAE) threshold. Both splitters were tested under adverse conditions and with compositions involving three components with properties representing typical mass fluxes and components concentrations in industrial and technological systems: phosphate concentrate 89.00 per cent (<500 µm), slag ten per cent (>2 mm) and glass spheres one per cent (750–1000 µm). The slag particles vary widely in particle shape, aspect ratio and surface roughness, while the glass spheres are extremely prone to bouncing and segregation (spillage). This test system is extremely difficult to split and thus constitutes a realistic worst-case scenario. While the vCSS does not comply strictly with Theory of Sampling demands for correctness, both splitters may well be able to deliver fit-for-purpose representative results if/when tested properly. Average relative mass deviations ranged from 1.89 per cent for phosphate concentrate (relative standard deviations of 20-fold repeated splitting) to 4.72 per cent for glass spheres and 13.04 per cent for slag. For the RSS, the average replication experiment splitting variation was 2.89 per cent for phosphate concentrate, 4.82 per cent for glass spheres and 11.1 per cent for slag. Both new automated online splitters would therefore appear to be able to be tuned to fit-for-purpose representivity (defined here as maximum relative reproducibility <5 per cent) for many non-extreme materials; however, it is always imperative to test every new type/class of material empirically. There is a wide commercial potential for important materials and commodities sectors, including food, feed, drugs (pharmaceutical), secondary raw materials, recyclates, agricultural products and seeds.CITATION:Lischka, M, Hollweg, A and Esbensen, K H, 2017. New online/atline splitter designs for laboratory automation – feasibility results, in Proceedings Eighth World Conference on Sampling and Blending , pp 159–166 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

The Bega granite at Whipstick, N.S.W., consists of a granite metasomatically altered to leucogranites and a spessartite-granite. The ore occurs in pipes controlled by jointing and shows evidence of post-depositional tectonic forces.The principal ore minerals are molybdenite and bismuthinite, with minor amounts of uraninite, pyrite, gold, bismuth, joseite A, joseite B, tetradymite, chalcopyrite, arsenopyrite, and skutterudite. The gangue minerals are microcline, albite, quartz, muscovite, and spessartite, with fluorite, chlorite, magnetite, and biotite as accessory minerals.The intrusion of granite was followed initially by ascending metasomatic fluids which penetrated along joints to be trapped in the domed roof of the intrusion to form the leucocratic granite. Iron-manganese-rich fluids metasomatically altered the granite to a spessartitegranite which is associated with the later deposited ore.Quartz veins and dykes of varying composition post date the ore deposition.

Jan 1, 1968

The importance of timbering, not only from a financial point of view but from an actual mining point of view, is so often overlooked or slightly glossed over by the average expert and investor, that I have thought it would prove interesting to go into the matter and to invite discussion upon the subject. We will first take small veins, or reefs as they are termed in some mining countries; and by small veins it is intended to denote fissures from a few inches to three feet. The ore body is supposed to be confined within well defined walls free from gangue matter, unless the casing can be defined as such. Now, if the walls are smooth and moderately hard, no timbering is required other than the stulls, which are braced from wall to wall in order to form platforms or stages to stope from. Should the reef from wall to wall prove payable, or should the vein be of a character to prohibit cleaning or sorting; and it be determined to send the whole of the stone to the, reduction works, the stuUs should be left in place until the section or block of ground is worked out, in order that if a weak spot in the walls (especially the hanging) occur, it would be possible, without any particularly extra expense or difficulty often times accompanied by danger to brace and secure the slabs. After the block became entirely stoped, it would pay where labour was cheap to remove the majority of timbers to stull another section.

Jan 1, 1901

By S Mundell, A Atkins, S van de Water

Geoscientific information management enables the capture, management and delivery of the original geoscientific observations and measurements of the earth’s natural resources. However, original observations and measurements are worth nothing if the quality and integrity of the data can’t be guaranteed. Geoscientific information is one of the fundamental assets enabling miners to make confident and accurate business decisions, whether that is defining a resource model, performing reconciliation, delivering ore reserve reports or meeting environmental compliance requirements. Without access to reliable, validated or verified data it increases the risk of miners using incorrect information for reporting and compliance. Industry codes, such as JORC, or government regulations, such as environmental compliance requirements, must be adhered to and companies should be able to confidently report to these standards. Without having a robust information management framework in place, it becomes a challenge to make trustworthy decisions, report confidently and reduce the risk of non-compliance. As a key initiative, good data governance should form one part of a miner’s information management strategy. Within the mining industry it is common for companies to only consider technology tools as the key focus for compliance whereas a mature information management focus will additionally consider people and process. All three pillars are critical for a miner to have confidence in their data driven decisions. This paper discusses an industry framework for best-practice geoscientific information management based on the observations gathered from analysing data management practices within the mining industry. It focuses on how the three pillars of people, process and technology are crucial elements to improve operational decisions and ensure companies are compliant.

Nov 8, 2021

By B E. Hall, D B. Kahler

"'Optimisation' has become a catchcry among many mining companies looking to tell the market how mining businesses will be improved and shareholder value increased. Consequently, the term 'optimisation' has been adopted by many service providers as they look to assist mining companies in achieving their objectives. But the explosion of services and products being offered with the label 'optimisation' has created some confusion. Mining companies ask for help in 'optimising' and service providers offer their assistance because they have a product that has the word 'optimisation' in its title. This is of course an over-simplification, but not by much! The authors' discussions in recent years with both mining companies and service providers have uncovered a number of very different definitions of optimisation.This paper provides a framework for identifying the scope and approach of different mining optimisation products and services, particularly the distinction between optimisation of components of the operation and the business as a whole. The different types of business optimisation are discussed, highlighting the failings of the mining industry's typical approach of strategy selection (as opposed to strategy optimisation). Mining business optimisation is discussed as a wicked problem, with the implication of this on how strategy optimisation models should be used and what the objectives of a business optimisation study should be.Case studies are also included to illustrate how fully flexible strategy optimisation models have been applied to assist decision-makers understand the impacts of changes in one part of the operation on the whole mining and treatment process, from geological models to the sale of product to customers.CITATION:Kahler, D B and Hall, B E, 2016. Strategic decision-making in mining – business optimisation using flexible evaluation models, in Proceedings Project Evaluation 2016, pp 215–225 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By J P. Sykes, A Trench

"World-class mine projects are increasingly failing to become world-class mines. Non-technical, socio-political and environmental problems seem, in part, to be the cause. However, the intangible and qualitative nature of these problems means overcoming them will require a greater systemic understanding of how the various technical and non-technical factors interact. This is particularly important as the concept of sustainable development has changed the industry paradigm sufficiently that it is no longer clear what world-class means. Finally, this better systemic understanding of mine projects needs communicating back to the exploration sector to improve exploration targeting.However, a disconnect between the exploration and mining sectors and between geologists and mining’s other professional disciplines means this is currently not possible. The use of economic evaluation techniques to assess the risk and value presented by the various technical and non-technical factors can assist with this by giving the varied professions a common language and including inputs from all disciplines. This paper therefore suggests a theoretical framework for analysing the various technical and non-technical factors, particularly the most challenging intangible and qualitative ones, and incorporating them into the typical economic evaluation techniques used in the mining industry.Understanding the risk and value relating to both technical and non-technical risks, however, places a greater emphasis on mining geologists to be conversant with a wide range of disciplines. Mining geologists will have to develop three types of knowledge:focusedinter-disciplinarybroad. In addition, they will have to become systemic thinkers to connect these types of knowledge. This multidisciplinary approach will require the use of fundamental critical thinking skills, common sense, intuition, experience and quantitative modelling techniques, dependent on the situation. As a result, both companies and professional societies, such as the Australasian Institute of Mining and Metallurgy, will have to develop ways of improving mining geologists’ inter-disciplinary and broad knowledge.CITATION:Sykes, J P and Trench, A, 2014. Resources versus reserves – towards a systems-based understanding of exploration and mine project development and the role of the mining geologist, in Proceedings Ninth International Mining Geology Conference 2014 , pp 243–270 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 18, 2014

By D Connelly

Silver and gold bearing ore from the Troy Resources NL Casposo Gold-Silver Project, located within the San Juan Province of Argentina contains a complex mix of gold, silver, electrum and silver sulphides in the ore. Casposo is a typical low sulphidation epithermal style gold–silver deposit where mineralisation is hosted within rhyolite – andesite flows and breccias. Veins are typically banded quartz–chalcedony colloform - crustiform banded with quartz - carbonate infill. Mineralisation is associated with an assemblage consisting of quartz, chalcedony, adularia, calcite, illite, sericite and trace sulphides. Gold and silver occur as electrum, native silver, sulfosalts and silver sulphides. This paper presents a case study that describes the process selection, development and engineering of a tailored process plant for the recovery of gold and silver from this ore.The original feasibility study, modelling, metallurgical testwork and engineering studies are outlined. The final flowsheet was based on minimising capital cost, operability, recovery and minimising technical risk.The process flowsheet uses the traditional Merrill Crowe route because of the high silver to gold ratio in the feed and achieves maximum gold and silver recovery while providing a common facility for future ore body treatment.

Aug 8, 2011

By S Strong, L I. Sanz Vivanco, T Brown

One of the most significant technical and practical challenges facing the tunnel construction team on the Legacy Way road tunnel project in Brisbane, Australia was how to erect the prestressed precast concrete slabs to form the smoke duct in the tunnel boring machine (TBM) tunnels.An essential part of the tunnel ventilation system, the smoke duct extends the full length of the 4.6 km-long twin two-lane tunnels. The vast majority of the tunnels (approximately 4.3 km) were constructed using two 12.4 m diameter double-shield TBMs. The refurbished Herrenknecht machines broke several world records on the way to completing the tunnel excavation works in just over nine months. With the excavation complete the focus turned to solving the complex civil tunnel fit-out challenges. A key component of the civil fit-out of the tunnels was constructing the smoke duct in the TBM tunnels, which was designed as a precast solution.The slabs, which each measure 8.62 m long × 2.0 m wide × 200 mm thick and weigh close to 9?t, need to be erected above cast in situ corbels whilst other tunnel finishing works continue. The space-proofing clearance offered by the design to the support corbels below and the precast segmental lining above was in the order of only 100 mm.This paper tells the story of how the Transcity Joint Venture (JV) tunnel fit-out team comprising some of Europe and Australia’s leading tunnel construction specialists drew upon the global strengths of the existing JV member companies and the global reach of leading TBM manufacturer Herrenknecht to develop an innovative system in solving this challenging problem. This globetrotting story, which starts in Australia, visits Europe and mainland China before returning to Brisbane where it all began.CITATION:Brown, T, Strong, S and Sanz Vivanco, L I, 2014. How the global experience and reach of tunnelling’s true multinationals helped solve a road tunnel fit-out challenge, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 507–512 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By R Jacobs, J Yeates

"The Stockman base metals project is situated in State Forest in the alpine area of East Gippsland, Victoria, adjacent to a National Park and within the headwaters of a major Ramsar-listed wetland catchment and the Murray-Darling River system. Site topography is steep, and elevated (650 m – 1200 m above sea level), and subject to circa 1 m annual rainfall, with occasional winter snowfall. The project consists of two volcanogenic massive sulfide (VMS) deposits to be mined by underground methods and treated in a 1.0 Mt/a central concentrator to produce copper and zinc concentrates for export over a ten year operational life. New resource projects are rare in Victoria. Recognising the sensitive setting, planning for the Stockman Project, which is now in the advanced permitting stage, has focused on balancing economic, environmental and social outcomes to ensure social licence to operate is secured and can be maintained. This has involved close attention to triple bottom line (TBL) risks and outcomes. Stockman has successfully gained State and Federal approvals via the Environmental Effects Statement process. The process of obtaining these approvals has required close attention to effective stakeholder involvement, and management of a lengthy and difficult approvals process, which is still to be finally concluded. This paper is a case study of the process of that permitting and the issues encountered to date. Key learnings from the experience have included: successful approvals require close attention to much more than just the project and its technical aspects and physical setting – effective stakeholder involvement and endorsement is critical the differing consultation requirements for local, regional and government stakeholders, to design and plan implementation of a project to meet TBL objectives, and to gain social licence to operate within the Victorian approvals process, the need for an effective lead government agency with policy authority dealing with material policy change requiring post-closure financial sureties estimating realistic permitting time and cost during the project evaluation phase. CITATION: Jacobs, R and Yeates, J, 2016. Stockman base metals project – sustainability, social licence to operate and permitting lessons learnt, in Proceedings Project Evaluation 2016, pp 98–110 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By K J. Ward, C N. Hatton, J Scalia IV, C A. Bareither, D L. Spencer

The mining industry is experiencing change in the governance of tailings facilities (TFs). Guidance and regulations across many jurisdictions contribute to this amorphous change. The Canadian Dam Association, Mining Association of Canada, Australian National Committee on Large Dams, and the Global Industry Standard on Tailings Management, produced by the International Council on Mining and Metals, are establishing guidelines for more rigorous industry governance. Evolving guidance regarding TFs is developing concurrently with a shortage of experienced tailings engineers, which adversely affects the resource base available to support new governance. This paper presents an updated semi-quantitative estimate of the impending resource shortage of qualified tailings professionals. Updates are provided herein for the estimated number of TFs worldwide, which included available data on active and inactive TFs, as well as the estimated labor resources required to service these facilities. The tailings labor shortage is discussed in the context of academic and professional training currently available to increase the quantity of trained personnel. This paper represents a discrete moment in time as contributions to the available information and inventories accessed continue to improve, but as of today are incomplete. However, the data and information included provide insight into the resource deficiencies currently within our profession, training and education opportunities to address those resource deficiencies, and a snapshot of a recent professional training course offered on mine tailings.

Jul 1, 2021

By B Hayter, M Carr, K Williams, C Wheeler, W Chen

Current trends into mining iron ore have seen an increase in the exploitation of problematic orebodies that would typically be disregarded. These bulk materials cause problems within all facets of the material handling stream, from remains left in train wagons to transfer chute blockages, which can cause costly downtime to mining operations (Roberts, 1998). These problematic bulk materials are referred to as wet and sticky material (WSM) due to the adhesive and cohesive nature they possess. Their characteristics can be computationally expensive to model. With the development of discrete element modelling (DEM), in conjunction with advancement in computational power over the past decade, it is now more feasible to model WSMs into the DEM technique.This research will couple two different contact models that can represent the characteristics of a WSM. These models include the Simplified Johnson-Kendall-Roberts (SJKR) and the Easo liquid bridging contact models. The SJKR contact model is an expanded form of the classic Hertz model. This model includes the tensile forces that are in the contact zone between two bodies when they are separated, which the Hertz model failed to capture (Johnson, Kendall and Roberts, 1971). The Easo liquid bridging contact model accounts for the capillary effects and surface tension that will form between two bodies, such as that of a WSM (Soulié et al, 2006). Both of these models were coupled to give the best representation of a WSM, which was simulated using MoleculeX™ (Chen and Williams, 2017) as the software platform.Additionally, this research also investigated the adhesion of problematic iron ore samples onto impact plates under dynamic conditions. An experimental set-up consisting of an apron feeder and inclined impact plate was utilised, to gain an understanding of the way the material builds-up and the possible modes of failure that could be experienced. This was undertaken for different wall liner materials, wall liner angles and moisture contents of the iron ore samples. From this, a series of DEM calibration simulations were conducted on the experimental set-up and particle size distributions (PSD) of the iron ore samples. This enabled forming of a database of parameters, which can be scaled for on-site applications in relation to geometry of the plant and PSDs that would represent run-of-mine ores.CITATION:Carr, M, Williams, K, Chen, W, Hayter, B, Roberts, A and Wheeler, C, 2017. The dynamic adhesion of wet and sticky iron ores onto impact plates, in Proceedings Iron Ore 2017, pp 511–518 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By B Hartmann

In 2003, Independence Group NL purchased the Long Shaft Nickel Mine complex (Long) in Kambalda, Western Australia. Lightning Nickel, the nickel operating arm of Independence Group, faced considerable challenges operating the mine, with the most significant challenge being able to prove that the remnant ore at Long and the associated orebodies could be mined safely and efficiently. Given the seismic history at Long, the magnitude of these challenges could not be underestimated. In an effort to achieve 100 per cent extraction of the flatter orebodies, traditional methods such as room and pillar were dismissed. A method consisting of transverse sills, butting into each other was proposed. To stop fill material from the first sill rilling into the adjoining sill, it was proposed to backfill the sills with pumped cement fill. The capital cost of the fill plant was estimated to be in excess of $1.5 million and the cost for cement alone was $1.0 million per annum. Shotcrete was already an extremely useful tool in dealing with the widely variable stress environment, but was to be used in an innovative manner that would enable the full extraction of a tabular section of the Victor South orebody. A layer of shotcrete, approximately 100 mm thick, was to be sprayed on the up dip wall of the initial development sill. The sill was to be backfilled with ænormalÆ development waste and ætoppedÆ with sand backfill. The next sill, ie slightly up dip and alongside, was to be mined along the shotcrete boundary wall. With respect to wall stability, the premise was that the shotcrete wall would stay in place and prevent the backfill (development waste and sand) from rilling into the adjoining development. It was also proposed that any breaches of the shotcrete wall would be repaired using shotcrete before substantial inflow of backfill into the ænewÆ development. This paper describes the development and implementation of this mining method, as well as some of the associated financial aspects.

Jan 1, 2008

By A Croll

A panel cave using LHDs for ore extraction came into production at Premier in 1990 at a depth of 630 metres below surface on the western side of the mine in the BA5 mining block. A post-undercut mining sequence was used with all development on both the undercut and production levels completed prior to the undercut being advanced over the pre-developed drawbells. Support and rock mass damage on the production level was extensive as the undercut moved overhead. Undercutting and coarse fragmentation created problems. The mining sequence was changed to an advance undercut with the minimum of development and support undertaken on the production level prior to the undercut moving overhead. Only once the abutment stresses had stabilised were drawbells developed and final support installed. The height of the undercut drill design was decreased from 18 to 13 metres. The changes resulted in markedly less rock mass and support damage on the production level. Lessons learned in the BA5 mining block on the 630 level were incorporated into planning and scheduling the BB1E mining block which came into production on the 732 metre level on the eastern side of the mine in 1996. An advance undercut mining sequence was planned, undercut height was minimised and undercutting parameters were optimised in terms of the BA5 experience. Numerous problems still occurred. As the undercut area increased in size severe spalling from the cave back resulted in vertical propagation of the cave to a height of 30 metres instead of the planned 13 metres. The resultant coarse fragmentation created secondary blasting problems and an excess of undercut ore that had to be loaded and trammed, slowed the rate of undercut advance. The planned mining sequence was compromised and considerable support and rock mass damage resulted on the production level below. Once these problems had been overcome the undercut advanced at the planned rate and continuous caving initiated at the predicted hydraulic radius. At a later stage the unexpected ingress of water hampered undercut drilling and slowed the rate of undercut advance in a section of the cave. Leads and lags between adjacent tunnels and the overall face shape could not be developed as planned. The rate of natural horizontal cave propagation exceeded the rate of undercut advance and three undercut drilling tunnels were extensively damaged. More tunnel development on the production level prior to undercutting than was planned resulted. The slow advance of the undercut and high abutment stresses caused extensive damage to installed support and the rock mass on the production level, 15 metres below. Experience in the BB1E mining block on the 732 metre level has taught that an advance undercut mining sequence reduces damage on the production level markedly. Extremely tight control on the rate of undercut advance, leads and lags between adjacent tunnels and overall undercut face shape as well as extraction ratio, tunnel development and support sequence on the production level below is required. Premier Mine plans to implement a block cave at a depth in excess of 1000 metres within the next decade. All the experience gained on current mining levels together with data collection and numerical modeling is being used to plan the proposed mining operation. The geotechnical challenge of mining at this depth in weak rock has been identified as the greatest risk to the project. Challenges centre around adopting the correct mining sequence, limiting the extent of rock mass damage associated with undercutting and effective support. The hydraulic radius needed to initiate caving, fragmentation, drawpoint spacing, secondary blasting and the possibility of seismicity are geotechnical concerns that are being addressed. Results to-date suggest that a pre-undercut mining sequence with all development and support on the production level carried out only after the undercut abutment stresses have passed overhead will have to be implemented.

Jan 1, 2000

By T D. H McGrath, W P. Staunton

Benchmarking, comparing an operation or process with the industry standard, is known to be a useful method for identifying plant optimisation opportunities, and in many cases providing the pathway to realise the benefits. The difficulty is generating the database of plant data necessary for a benchmarking exercise. Larger companies can benchmark internally; this option is not available to smaller companies, and the full value can only be realised with a comprehensive “industry wide” approach.The Gold Technology Group at Curtin University through the AMIRA P420 series of projects has undertaken several comprehensive metallurgical industry surveys in the gold industry over the last two decades. Analysis of these surveys has demonstrated areas where many operations can benefit from re-assessment of their operating practices.This paper will review the work undertaken by the Group in this area, in particular the 1999 surveys of gold companies in the Australasian region, and the 2012 international survey of the industry. The challenges of, and opportunities arising from these surveys will be discussed. Some of the highlights from analysis of these databases will be presented as well as noting changes in processing practices observed by the Group over the last 20 years.CITATION:McGrath, T D H and Staunton, W P, 2018. Keeping up with the Joneses – the value of industry surveys and benchmarking, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 509–516 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

One of the most significant problems experienced in land reclamation work has been the tendency of earthmovers to over-compact the subsoils and topsoils. The need for extensive subsoil drainage, because of over-compaction, becomes a very expensive exercise and can be attributed to poor planning. The problem has been addressed both at the Waihi and Huntly open-cast mines through the use of low ground pressure machines in the placement of subsoils and contouring. The use of subsoilers working to contour to aerate the soils is essential to integrate both the sub and topsoils so that significant root growth and drainage is established. Waihi's rainfall (approximately 200 mm annually) and light soils create difficulties in preparing for the final seed bed. A noticeable factor in preparation of the growing medium was the reaction of the lime particularly in the subsoils (damp), from a lumpy, quite heavy texture to almost a seed-bed texture within a period of approximately 72 hours. Also the high incidence of stone and debris which was not apparent in the placement of subsoils meant the job became very labour intensive. This will be overcome with the importation of a machine from the USA. All of the rubber tyred tractors used on these projects are four wheel drive in the 6S-aOhp range which for weight distribution and the safety factors allows for good landscaping techniques. Good engineering practices should ensure that slopes of no more than 3:1 be designed, keeping in mind that the long term planning must allow for maintenance and stock management of restored land.  In the preparation of the final growing medium the equipment used included: Caterpillar 05 LPG and blade; three-four wheel drive rubber tyre tractors; Super flow subsoiler; hydraulic twin spinner manure spreader; discs û two types; harrows; MF Seeder; Cambridge Roller and Duncan Rotatiller.

Jan 1, 1991

By DV Boger

Rheology is the science which deals with the deformation and flow of matter. Thus nccology is concerned with the flow of any material. The mining industry is concerned with digging things out of the ground, extracting the good stuff and throwing away the had stuff. In the upgrading processes associated with mining, is mineral processing, wet techniques are used where the primary material being handled is a particulate fluid, ie a suspension. After the processing operation, with the concentrates extracted, what is left behind generally is a wet material in suspension form, which may or may not contain reagents harmful to the environment. The amount of waste generated in any of the mining processes is large, in fact, the mining industry is the largest generator of solid waste in Australia. In order to minimise the waste generated within the industry it has become of interest to handle the particulate fluid wastes, or suspensions, at high concentrations, thus removing water and some of the reagents which may be harmful to the environment. The resultant highly concentrated suspension is a non-Newtonian hold Rheology deals with the flow of non-Newtonian fluids; therefore i combination of rheological understanding of high density suspensions. ill conjunction with an understanding of the environmental problems hero' faced by the mining industry, can and has led to improved methods of waste disposal in the industry, ie waste minimisation. This paper describes the progress that has been made in the development of dry disposal technology in the mining and minerals industry in Australia.

Jan 1, 1998

By K Ringwood, J Cummings, C J. Moran

The development of a water accounting framework that enables consistent and contextual reporting of minerals operationsÆ water use, represents a key sustainable development objective that many Australian minerals companies have committed to. A future water accounting framework will require: key terms and definitions for water metrics for use in the Australian minerals industry that are consistent with the wider water sector, a suite of metrics representing key components of an operationÆs water balance, a calculation method for some of the metrics, and a reporting protocol. This paper presents the methodology that was used to derive these four components. Existing accounting frameworks were reviewed and key terms and definitions that were consistent with current regulatory requirements and voluntary approaches were proposed. A calculation methodology was developed to obtain some of the key indicators and variables that cannot be easily measured directly (eg water loss through evaporation). The adopted terms and definitions typically require a combination of empirical and estimated data. To test the proposed definitions and calculation methodology, values for water metrics were derived for eight sites, selected to test a variety of commodity and biophysical situations. The proposed framework and definitions could deal with the specific situations selected as case studies. The associated calculation methodology produced complete accounts at various levels. Some elements of the accounts could be directly checked against available data and simulations. The framework captured well variations in the reuse efficiencies; reuse efficiency could even vary for similar processes. It is concluded that this preliminary accounting framework provides a consistent language and metrics for quantifying and communicating water management, both at the intersection of the site with the surrounding landscape (through detailed reporting of site inputs and outputs) and within operational activities. Using this consistent framework for quantifying and documenting water use within an operation will provide a platform for compiling and comparing minerals industry water use with other sectors. This may support benchmarking activities within regions or companies and help demonstrate leadership amongst water users in water resource stewardship. The approach presented here is applicable to a wide variety of mining and processing activities, and biophysical environments, and following a period of stakeholder engagement and third party review, is being refined as a first step towards developing nationally consistent water use reporting for the Australian minerals industry.

Jan 1, 2009

The presence of undetonated explosives in a rock face after firing constitutes a hazard which can result in a fatal or serious accident if undetected before drilling commences.Most accidents caused by drilling into explosives are the result of failure to examine the working face properly and lack of care in subsequent drilling operations; it is not always realized that explosive may be left in the butts of holes or may be driven into cracks or crevices in the rock.Obviously the best means of preventing accidents of this nature is to adopt methods of drilling, charging and firing which will reduce the hazard to a minimum.There are three ways in which undetonated explosives may be left in the rock face, namely:1. Misfires.2. Cut-off shots.3. Incomplete detonation or failure of the charge to propagate throughout.MisfiresNo attempt will be made in this paper to deal fully with the question of the prevention of misfires, as apart from the fact that most of the preventive methods are well known, it is believed that if the miner receives his explosives and means of initiation in good order, and proper care is taken in their use, the failure of a charge to fire will be a rare occurrence. The provision of central fuse capping stations on mines has gone a long way towards the elimination of misfires caused by the mishandling of safety fuse anddetonators.

Jan 1, 1956

Study on the Effects and Mechanics of Na2SO3 to Chalcopyrite and Galena

Sep 13, 2010