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By M Bezzina

In 1995 Standards Australia International Limited æSAIÆ published a risk management standard titled AS/NZS 4360 Risk Management. It was the first such standard published by a recognised formal standards body anywhere in the world and it put Australia at the leading edge of the risk management discipline. Many Australian and international organisations have utilised the risk management standard and it is one of SAIÆs most important and popular standards. Since its publication in 1995, the risk management standard has gone through a major revision in 1999 and is currently undergoing another such review, which is due for completion in 2004. This paper will chart the application of the standard within certain key organisations since its inception in 1995. A brief overview of the methodology behind AS/NZS 4360 will be presented as well as an overview of supporting and related standards. It is prudent to base risk management and other management system issues on existing and tested standards rather than creating new proprietary approaches. Examples of areas in which the risk management standard might be applied in the mining industry are given, subject to the specific operations of each company: technical, commercial, environmental, informational, and safety and regulatory.

Jan 1, 2003

By Parer W. R

During the last fifteen years there has been a marked change in the demand and supply patterns of coking coal. The world demand, predominantly Japan, has increased from 23 million tonnes of world export/import coal in 1960 to an expected total of at least 100 million tonnes by 1975. In the last ten years Australia has been the main beneficiary in the growth of the export coal trade. This has been brought about by its proximity to Japan and its large econ- omically mineable reserves of coking coal. A feature of the recent coal development in Australia has been the requirement of companies in new areas to provide massive capital for infrastructure costs. The ability of the Australian coal industry to retain a large share of the world export market depends to a large extent on reasonable costs to transport coal from mine to the market place. In some areas of Australia this means that railway lines, loading and unloading facilities, and ports will have to be up-dated at substantial costs. On the long haul to Europe the recent increases in the prices of bunker fuel have made the price of coal less competitive when compared with sources

Jan 1, 1974

Segregation of granular material is a very common phenomenon. Realised in a forced manner it is a basis of all separation processes in mineral processing, mainly classification and beneficiation. Spontaneous segregation, occurring under dynamic conditions and making possible mutual translocations of grains, is however an undesired phenomenon as a rule. It decreases the degree of blending of the material which in many cases is an important technological feature of the material. It should be noted that the segregation can be treated as the reverse phenomenon to blending. The importance and frequency of spontaneous segregation has caused many rules and technical solutions to be developed aimed at decreasing the possibility of the spontaneous segregation. However, not enough attention has been focused on an quantitative description of the phenomenon of segregation, either to ways of quantitatively evaluating segregation effects or to explanation of the influence of conditions under which the grained material exists on the occurrence of segregation and its degree. The paper presents the following topics: 1. new numerical indicator for evaluation of the segregation degree (and blending) of material contained in an arbitrary determined region is proposed; it is determined relative to the maximum possible degree of segregation of the given material when taking into account its individual properties; values of the indicator can be calculated effectively for an arbitrary material, also for ulticomponent material. 2. there is proposed a way of evaluating the state of segregation (or blending) of material in an arbitrary part of the region mentioned above, based on investigation of the gradient of distribution of the material features; algorithms of analytical procedures and calculations are presented for typical cases met in mineral processing; 3. results of initial experimental studies, both laboratory and industrial, concerning the effect of the chosen factors occurring in transport and storage of the material on its degree of segregation are presented; and 4. conclusions referring to the fundamental and practical significance of the results are also presented.

Jan 1, 1993

By Holla L

There exist several legislative provisions in N.S.W. which work together to control surface subsidence due to extraction of coal by underground methods. The important ones are the Coal Mining Act, Coal Mines Regulation Act, Mine Subsidence Compensation Act and Dams Safety Act. In addition, there are guidelines laid down by the Chief Inspector of Coal Mines for mining under and in the vicinity of tidal waters and the ocean. There are also conditions of coal mining leases and conditions of approvals given to undertake various methods of mining which stipulate further controls. The legislative provisions and relative controls are designed to minimise surface damage, ensure safety , of major public utilities, control- surface land use and compensate damage caused by subsidence as a result of coal mining operations. They aim at balanced and responsible development of our valuable coal resources consistent with adequate safeguards to surface improvements and natural features. The paper discusses in detail these legislative provisions and the mechanics of their operation with a view to emphasising the fact that underground coal mining operations are undertaken responsibly and in a planned and rational manner for the overall benefit of the community. Further, the paper aims to demonstrate the need for legislative measures and conditioning of mining operations to keep abreast of developments in the knowledge and skills of mining and subsidence engineers and continuing improvements in mining technologies. Likewise there is a need on the part of engineers and those associated with introduction of new technologies to appreciate the requirements and existence of legislative and other measures having a direct or indirect association with surface subsidence as a result of coal mining operation.

Jan 1, 1986

Elimination of zinc by the reduction of iron works dusts is examined. The process consists of blending, filtration, drying, balling, preheating and reduction in the rotary kiln. Dust slurries and dry dusts are mixed and stored in slurry basins and the blended slurry is filtered. In the balling process it is important to make green pellets which will withstand Thermal shock in the preheater and rotary kiln. Preheating to about 2000C is preferred to ensure effective use of coke fines in the blast furnace dust. The coke retained in the pellets accelerates the reduction rate. However, at the initial stage of the reduction the pellets become weakened and have to be heated slowly to prevent ring formation. In order to ensure zinc vaporization, pellets should be heated to a temperature of 1100-11500C in the kiln with injection of l ignite fines from the discharge end. Pellets having a degree of metallization of more than 90% and containing less than 0. 1% zinc have been obtained using a test kiln. The final pellet product is intended for use as blast furnace feed. A new plant with a capacity of 20, 000 tonne of dust per month is now under construct- ion and will be in operation next year.

Jan 1, 1974

By Y Wei, H-B Mnhlhaus

Particles are by far the easiest objects to simulate, because their dynamics is simple. Determining the motion of particles and their interaction, a wide variety of deformable structures can be constructed by connecting particles that have mass, position, and velocity, and that respond to forces. Starting from this simple idea we have derived what we call the particle-lattice method for the solutions of boundary value problems of deformation and fracture of solid mass. The problem of rock breaking by blasting operations as well as fracture and flow of rocks fragments involve momentum transfer between solid and fluid; gas flow and reactive mass transfer. In this paper we outline the method and describe briefly the salient features of the algorithm. We derive relationships between the contact properties for the discrete model and the properties of the underlying continuum and fluid flow coupling procedure. Finally we illustrate the potential of the method by means of example solutions related to the dynamic fracture and flow in jointed rock by blasting.

Jan 1, 1999

By D Whitworth

The Golden Pig mine has embarked on a diamond drill program design philosophy that increases flexibility of the program by greatly increased drill pattern densities. The use of standard broad pattern diamond drilling at the Golden Pig mine has previously lead to operational inefficiencies and impacted significantly on the costs of the mine. The diamond drill program philosophy and its interaction with mine planning is explained. The case study of the E lode mining as used to internally justify the increased drill densities is detailed.

Jan 1, 2002

Western Deep Levels, a seismically active deep level gold mine, started placing backfill in their narrow tabular workings as part of the regional support strategy in 1986. Over the years the percentage of working places being backfilled has been gradually increasing. At the end of 1995 the support efficiency and the labour productiveness relating to support installation were scrutinised to determine if resources were being optimised. Owing to financial, safety and productivity constraints it was decided to redesign stope support to be less labour intensive, safer and provide an integrated stope support system. This new integrated system will thus combine the previously used temporary, permanent and back area support consisting of mechanical props, hydraulic props and backfill respectively. Backfill previously formed an integral part of the regional support in conjunction with strike stabilising pillars. To design the integrated support system the backfill placement quality has to be exceptionally good and placement must be done as close as possible to the working face. The backfill to face distance was reduced by 30 per cent and in some areas by more than 50 per cent with an increase of square metres filled to increase the effect of the backfill even more. This paper addresses the design and successful implementation of an integrated stope support system based on the optimisation of backfill to the extent where installation of mechanical and hydraulic jacks could be eliminated.

Jan 1, 1998

By L Reynolds, N Whetter, S C. Cox

The Reefton Goldfield has had the largest hard-rock gold production (64 t Au) on the West Coast of the South Island of New Zealand, and is currently under renewed development by Oceana Gold. The gold predominantly occurs in variably sheared quartz veins that are associated with zones of tighter, shorter wavelength folds in the host Greenland Group metasediments. The quartz veins typically occur as a series of plunging shoots that align with specific fold limbs or fold hinge zones. Shear zones containing disseminated mineralisation and quartz veins have thickness variations that relate to the angular relationship between the shear and host-rock bedding. Exploration strategies and targeting can be developed around both types of structural control.

Jan 1, 2005

Stawell Gold Mines Pty Ltd operates two underground decline mines within the township of Stawell. An active exploration program and commitment by owners to improving the ore reserves has led to an improved mine life and reduced operating costs since the purchase of the operation by Mining Project Investors and Pittston Mineral Ventures in late-1992. Over the past six years of operation a cumulative 1 150 000 ounces of gold have been added to the mineral inventory. An improved geological understanding of the orebody has evolved over time increasing the ore reserves and allowing the development of long-term plans for the mines future. This has enabled important capital decisions to be made providing the impetus for improved productivity and thereby reduced operating costs. Co-operative mine planning and mine geology utilising best practice geological systems have enabled the effective extraction of a structurally complex and mineralogically varied deposit within a rural Victorian township. Detailed metallurgical research has improved the function of an aged and poorly designed circuit to boost the mill capacity whilst also improving the metallurgical recovery. The combination of metallurgical expertise and an understanding of the geological setting enable an effective control of metallurgical recovery.

Jan 1, 2000

Many parameters are important when considering the performance of a concentrator. These include metallurgical performance, such as throughput, metal recovery and final concentrate grade and operating costs, such as power consumption, water usage, reagents and spare parts. In most operations the objective is to maximise metallurgical performance and minimise operating costs, ideally without a large investment in new capital items. A number of projects have been carried out at Newcrest MiningÆs Cadia Valley Operations (CVO) with the aim of improving metallurgical performance and minimising operating costs. This paper focuses on the installation of newly designed flotation mechanisms in various cells in the Cadia flotation circuit and describes the effect these changes had on performance and operating costs.

Jan 1, 2009

The design and construction of a 2.5 million tonne per annum ship unloading system at the PWCS export coal terminal in Newcastle, NSW, has further increased the flexibility and sophistication of Australia's largest coal export facility. The system comprises a new unloading wharf serviced by a self unloading vessel, conveyor stream and multi compartment ground level storage shed. Coal is reclaimed from this shed by the largest portal scraper ever installed under cover. The system also provides additional flexibility by receiving coal from the existing PWCS road receival to improve scheduling. The PWCS can now simultaneously handle 11 coal types and receive from rail, road and sea at almost 15000 tonnes per hour.

Jan 1, 1987

Erosion of unprotected batters, spoil banks, slopes, and stockpiled material creates a multitude of environmental problems. Winds blowing across these denuded surfaces can generate dust clouds capable of depositing un- desirable particulate material a considerable distance from the source. Water eroding these areas continually exposes new surfaces which may be oxidized. Iron pyrites can be dissolved in the flowing water, resulting in the addition of pollutants to streams and water sources. Silting of water sources can also occur as a result of this erosion. Valuable topsoil can be blown or washed away. In addition, the after-effects of erosion leave a visual pollution which is more difficult and expensive to correct than to prevent.

Jan 1, 1976

Topography, location of coal bearing land and existing built-up areas severely restrict locations for overburden disposal and dumping sites north of the Latrobe River clear of the coalfields are assumed until internal dumping areas can be established.

Jan 1, 1982

By Mudge S. T

Tin mineralisation occurs at Renison Bell, near Zeehan in Tasmania, as a group of cassiterite-bearing massive pyrrhotite bodies in Cambrian sedimentary rocks. Mineralising fluids from the underlying Pine Hill Granite have replaced carbonate rocks with massive sulphides and cassiterite. The discrete blocks of massive pyrrhotite have high density and high magnetic susceptibility contrasts with the comparatively barren country rock. They are strongly remanently magnetised and are excellent geophysical targets. A detailed geophysical model of the mine was created from a database comprising 1:2500 scale geological mapping and geological logs of approximately 4000 drill-cores. The model comprises 93 parallel cross-sections, each 1.5 km long, spaced 20 m apart. Each cross-section is comprised of up to 150 polygons which represent all known individual rock types and orebodies. The magnetic response of the model was computed and the residual between the model and the observed response, measured by a low-level helicopter magnetic survey, revealed several anomalies unaccounted for by the model. Drill testing of these anomalies led to the discovery of several hitherto unknown massive sulphide occurrences. Surface gravity data of the mine and surrounding district were enhanced by applying digital terrain corrections. The corrected Bouguer anomaly revealed a hitherto unknown positive anomaly associated with the ore zones of the Renison mine. The gravity anomaly of the model was also computed. Unfortunately, the limited resolution of the observed data prevented the delineation of ore targets. The terrain-corrected Bouguer gravity data were also used to model the shape of the underlying non-magnetic Pine Hill Granite. A computer inversion method was implemented to build a 3D block model of the granite. Results agreed with previous conventional 3D modelling techniques but yielded improved resolution of the granite form. The project involved development of new computer software to build and edit the large and complex 3D geophysical model of the mine and to compute the model's magnetic and gravity responses. Software was also developed to build and compute the gravity response of a 3D block model of the underlying granite.

Jan 1, 1997

Equity finance provides the most suitable and frequently the only access to capital during the exploration and evaluation stages of resource projects when project risk is at its highest. Investors are prepared to provide equity funds in the knowledge that they are compensated for the higher risk they take on with higher potential returns or sufficient upside potential to justify the higher risk. The context of resource projects which determines the role of equity finance has changed considerably. Prior to the resurgence of the gold price and the development of new mining technology many resource projects were selectively mining orebodies by underground methods frequently with limited reserves proved up in advance of mining. The limited proved ore reserves base and the volatility of the gold price all contributed to a higher risk and higher return investment environment in which the use of equity finance was more appropriate and frequently the only option for capital raising. The financial risk of a resources project can be transferred to an underwriter who makes the commitment to distribute the financial risk between a number of investors. There is also the opportunity for financiers to use a mix of equity and debt finance to allow a company to proceed with the development stage where without such a mix the resource project would not proceed. By using a level of equity finance the project becomes robust enough in its ability to service the debt finance facility and the project proceeds with the equity participants receiving a suitable risk reward return. The liquidity from the establishment of a market for the company's securities enhances further capital raising and generally enables the company to satisfy its financial requirements on more favourable terms particularly during bull markets. The role of equity finance in the management of the financial risk during the exploration, evaluation, development and mining stages of resource projects is summarised in Table 1. In more detail the principal roles of equity finance and the ways in which equity finance impact on the risk management of resource projects will be considered in turn.

Jan 1, 1994

In the past five years, there has been an evolution in the assessment and control of mining risks in the New South Wales coal mining industry. This change has involved the development and use of structured, systematic, team-based risk assessment exercises to identify, assess and control unacceptable risks to people, equipment and production. The outcomes have improved the management systems in the mine. This paper discusses the evolution of the risk assessment approach in equipment design and mine operations, as well as the specific risk assessment methodology. The paper also presents the reactive side of risk management, the method of investigating failures in the management system, usually referred to as incidents or accidents.

Jan 1, 1994

By J J. Plumb, P D. Franzmann

A study was conducted to describe the microbiology of the MICCL Monywa chalcocite heap bioleaching operation. Microorganisms were detected in the heap using culture-based techniques and cultureindependent PCR-DGGE analysis of the 16S rRNA gene. The metabolic requirements, temperature and pH optima were determined for selected strains isolated from the heap material. Six strains (BH1-BH6) were enriched and isolated from heap solids and leachate samples. Phylogenetic analysis of the 16S rRNA genes showed that strains BH3 and BH4 were closely related to the acidophilic bacterium Acidithiobacillus caldus and strains BH5 and BH6 were closely related to Leptospirillum ferriphilum. The optimum growth temperature for L. ferriphilum was 41.3¦C and the optimum pH range was 1.1 to 1.5. A new species of Archaea was isolated from the heap samples. Cells of the proposed species, Ferroplasma cyprexacervatum (æcyprusÆ L.n. meaning copper; æexacervoÆ L.v. meaning æto heap upÆ), are non-motile pleomorphic cocci, capable of chemomixotrophic growth with ferrous sulfate and yeast extract. Cells grow anaerobically on ferric iron in the presence of potassium tetrathionate and yeast extract as electron donors. Growth occurs from 14¦C to 63¦C, with an optimum temperature of 55.2¦C. The optimal pH for growth was 1.0 - 1.2. The species was phylogenetically most closely related to Ferroplasma acidiphilum with a 16S rRNA gene sequence similarity of 95 per cent. Molecular analysis of mine samples (16S rRNA PCR-DGGE) detected the above-mentioned cultured strains of microorganisms as well as species of Sulfobacillus and other unknown Proteobacteria. The microbial community of the Myanmar bioleach heaps contained similar levels of diversity to a dump bioleach operation in Chile, but contained greater amounts of biomass than another heap bioleach operation in Australia. The operating parameters of the Myanmar heaps (low pH and moderate temperature) have selected for the growth of moderately thermophilic microorganisms that are more commonly found in extremely low pH acidic mine drainage sites than in heap systems. The novel species of Ferroplasma is thought to be involved in the aerobic and anaerobic cycling of iron within the heap bioleaching environment.

Jan 1, 2004

In todayÆs demanding business landscape continual change and technological advancement is a given. With these changes there is now, more than ever, a need to ensure sustainable growth in respect of value protection and value adding whilst meeting the pressures and expectations of the societies in which we operate. Traditionally the management of safety has been a very reactive activity in the business, in some cases seen as an irritation and a disruptive process that demands a focus on preventing reoccurrences. This in turn has focused the measurement of safety performance on a range of lagging indicators û æafter the effect managementÆ. Gaining and maintaining a licence to operate is crucial to a sustainable business but as a prerequisite, organisations need to have a demonstrable ability to manage the safety of their people, as well as mitigating the people risk associated with the business activity. A major focus in the last decade has been on the implementation of enterprise risk management programs, where risk becomes embedded in all business systems and processes and the organisationsÆ genetic make up is programmed to analyse and integrate risk management into all facets of the business activity. The management of safety should be no different. One school of thought argues that there are no new accidents, but rather our inability to learn from the past. Others believe that as long as we have an appetite to achieve the unachievable, we will have to continue to push the boundaries, our safety comfort zones and inevitably take risks. Single reliance on highly evolved technical systems, elaborate processes, highly skilled people, safe equipment and safe work environments have shown one thing û they are not sustainable in providing adequate coverage in the business. In analysing a range of factors associated with some of the worst catastrophes of the 20th century, it can be suggested that they were in fact predictable and inevitable and that an integrated approach underpinned by sound risk management systems could have determined a different result. The key to a sustainable approach in the management of safety requires us to look at a multitude of aspects that collectively allow the performance of an organisation to be predictable. To have certainty in the business activities it is necessary to have controls in place that will mitigate the risks normally associated with unwanted events. It is ensuring that human factors effectively contribute to monitoring the planned approach and being able to safely adjust to any variability. In essence this is having the ability to proactively plan for the longer term. The sentiments articulated by organisational leaders echo that safety management is good business. Surely then a good business is a sustainable business, and a sustainable business is one that provides lasting benefits to its stakeholders.

Jan 1, 2006

By Lewis PC, Carr GR, Dean JA, Glen RA

The Lachlan Fold Belt (LFB) is a complex orogenic belt which developed in Early to Mid Palaeozoic time. A number of orogenies and more localised deformational events affected the region. A simplified classification scheme for the diverse gold deposit types is proposed, subdividing primary mineralizing processes into four categories: volcanism (epithermal and volcanogenic deposits), igneous intrusion (subvolcanic/porphyry style, skarn and magmatic deposits), metahydrothermal processes (deposits generated during metamorphism and regional deformation) and hydrothermal-distal processes (deposits generated by poorly understood, generally remote large scale hydrothermal processes). Major gold deposit associations include epithermal and porphyry style deposits in Ordovician-Early Silurian shoshonitic andesite sequences; volcanogenic base metal-gold deposits in Silurian rift or basin felsic sequences; vein deposits in Late Silurian and Early Devonian S and I-type granitoids; deposits in Early Devonian sedimentary rocks of the Cobar Basin probably generated by metahydrothermal processes during basin closure and cleavage formation; deposits associated with serpentinite; and metahydrothermal quartz vein deposits in folded sedimentary rocks.Studies of host rock geochemistry suggest a relationship between magma types, gold enrichment and mineralization particularly in shoshonitic sequences and Early Devonian granitoids of the Boggy Plain Supersuite. Structural studies indicate the importance of thrust type structures and detachment faults in generation and location of gold mineralization. Lead isotope initial ratios help define metallogenic associations and a number of distinctive isotope "signatures" have been established.

Jan 1, 1990