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Whilst the wider community is both a large consumer of mineral products and relies on mineral exports for much of the wealth which sustains it, the community generally has a poor perception of the minerals industry.   The role of professionals and The AusIMM in the "New Economy" minerals industry is reviewed. The new structure of The Institute is vital as we move forward in times of globalisation, rationalism, increasing litigation, criminalisation of risk and increased focus on corporate governance. This address looks forward to ways The AusIMM and professionals of the future are positioning themselves for these and other challenges.

Jan 1, 2001

The Ekati Diamond Mine is located on permafrost terrain in CanadaÆs Northwest Territories. The mine rock consists of: diamond-bearing and barren kimberlite; and surrounding waste rock such as granite. The kimberlite occurs in several vertical æpipesÆ that are, or will be, mined using open pits. Early predictions of drainage chemistry at Ekati identified the potential for ARD due to sulfide oxidation from both waste rock and kimberlite. This was surprising for the kimberlite, because neutralisation potentials (NP) are typically hundreds of kg CaCO3 equivalent/t. However, subsequent testwork showed that substantial portions of the NP ædisappearedÆ quickly, apparently due to the unusual non-carbonate mineralogy. In any case, additional predictive work concluded much of the rock was benign and there would be no ARD. Shortly after mining started, ARD appeared from both the waste rock and kimberlite, although a few years passed before the company and its consultants recognised that at least some of the acidic water was ARD. Numerous other processes have been put forward as possible explanations for the remaining acidic drainage, although none have been either confirmed or eliminated. Because: the causes of the ARD and acidity are not known; no causes have been eliminated and more have been added; drainage chemistry was not predicted accurately; and future mining will encounter similar rock. I believe the Ekati Diamond Mine needs high-level assistance to understand current chemistry and to avoid problems with future drainage. Organisations like INAP, MEND3, and universities could provide this assistance.

Jan 1, 2003

In redesigning the cyanide plant at Mount Torrens, in conjunction with Mr. L. W. Grayson, the manager, several minor alterations were introduced in order to have the operations under thorough control, and these having proved serviceable may be of sufficient interest to merit a description here. The lixiviation vats, though only 8 feet in diameter, were retained, but the pipes leading away from the bottom were reduced from two inches to half-an-inch in diameter, and had a fall to the zinc boxes of about 4 feet. As these small pipes were completely filled by the solutions fiowing away from the vats, they exerted a suction equal to their fall and thus hastened the rate of flow, so that tailings containing a larger proportion of slimes could be treated than was possible where the larger pipes were used, as, there not being sufficient fiow of solution to keep the latter filled, no suction could be obtained with them. It was found that with'most of the tailings treated a sufficient flow could be obtained from the half-inch pipes when the taps on, them were only one-third to half open. The lower end of each of these pipes was connected by means on indiarubber tubing with the sille hole of 11 in aspirator bottle, and to the mouth of this bottle a few feet of similar tubing was connected, so that the solutions coming through could be directed into either of the fixed tubes leading respectively to the waste water tank the strong solution zinc boxes or the weak solution zinc boxes.In working the vats, the following method was found to give good results. While filling the vats with tailings the taps were left open, so that the water might drain off into the waste water tank the surface of the tailings was carefully levelled. When the strong solution was run in at the top, the air contained in the interstices of the tailings was forced through the half-inch pipe at the bottom as a strong blast, instead of, as I believe js usual, escaping by means of channels formed by it through the tailings, and thus tending, it would appeal, to render the disposition of the tailings less even and to make.

By KEITH BARRONI

In the proposed criterion for coal a distinction is made between brittle and "psuedo-ductile" failure. This criterion is the basis for the development of new equations for coal pillar strength, including a transition from brittle fracture to pseudo-ductile yielding. In addition the equations obtained allow the critical minimum pillar dimensions to be calculated to avoid "catastrophic" and "ultimate failure".The validity of these formulae can be tested by comparing their results with pillar case histories derived from the literature.

Jan 1, 1988

The individual or company director who ignores his or her obligations under the Resource Management Act 1991 and under the proposed hazardous substances legislation, ignores them at their peril. Two recent cases in Canada and the United Kingdom concerning environmental offences under similar legislation illustrate the risks well.

Jan 1, 1993

By J Fut=

The rotary drilling of rocks is widespread technology in mining and in tunnelling. The paper describes the results of research by aim to find relationships between optimal drilling and sound signal of drilling machine. The optimisation criterion has been formulated as the minimisation of specific energy with maximal effective speed of drilling in process of the rock disintegration. The research in this field has been made on experimental drilling stand. Our monitoring system has measured following variables: the pressing force of core drill, the revolutions of drilling head, the length of drilling, the time, the power, and the acoustic signals. For measurement of acoustic signals have been used very sensitively sound meter MEDIATOR 2238. From this measurements have been processed acoustic spectrums. Then we are found relationships between optimal control of drilling and composition of acoustic spectrum. On base of experimental results, we can formulate the optimal control following: æTo achieve the minimum difference between the equivalent sound level at the load and idle modes only at the representative frequency (f = 1000 Hz)Æ. The representative frequency dependences on type of the rock New method based on these relationships enables the optimal control of drilling machine by using measured acoustic signals only.

Jan 1, 2003

By G Tripp, G Lorusso

The Velvet gold orebody (153 Koz Au) is located near the Kanowna Belle gold deposit in the Boorara Domain of the Kalgoorlie Terrane, a subdivision of the Archaean Eastern Goldfields Superterrane (Swager et al, 1990). Gold mineralisation at Velvet is hosted within an intrusion of intermediate composition that broadly follows a sub vertical hanging wall splay of the Fitzroy Shear Zone.Velvet was discovered in 2003 during an underground exploration drilling program targeting potential strike extensions to the Kanowna Belle deposit. Diamond drill hole KDU1595 returned a downhole intercept of 36 m grading 4.6 ppm Au approximately 500 m west of the deposit and at a vertical depth of 700 m below surface in the immediate hanging wall of the primary Kanowna Belle host structure, the Fitzroy Shear Zone. Subsequent drilling completed following the initial discovery, from both surface and underground collar positions, failed to replicate this result.In 2014, KDU1595 was resurveyed gyroscopically and the mineralised intercept correctly located. Additional drilling was undertaken to follow-up the repositioned discovery hole. Challenges included poor drilling angles through the Fitzroy Shear Zone, excessive deviation during drilling and the unknown geometry of the target. Navigational drilling helped to successfully penetrate the Fitzroy Shear Zone and in April 2015, drill hole KDU3234 returned a significant downhole intercept of 45 m grading 5.6 ppm Au.Additional drilling success resulted in a decision to develop a 600 m drive to serve as a dual-purpose access for further exploration and mining. This was a potential risk considering that the orebody geometry was unknown and all significant drilling results were clustered within a 50 m × 50 m panel. Development commenced in June 2015 and the first ore cut taken in April 2016. Geological mapping and structural interpretation, together with multi-element and spectral analysis of drill samples has enabled several other target areas to be identified for exploration. The Velvet mining area is critical to continued production at Kanowna Belle. Geological understanding must advance as mining progresses to ensure continued resource growth and optimal extraction of reserves.CITATION:Lorusso, G, Rogers, J and Tripp, G, 2017. Velvet underground exhumed – discovery and development of a new mining front at the Kanowna Belle gold mine, in Proceedings Tenth International Mining Geology Conference 2017, pp 169–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By A G. Thompson, E Villaescusa, A De Zoysa, J R Player

Ground support performance is critical to the safe and economical extraction of ore. This is particularly important for mass mining extractions at great depth, which are currently being considered by a large number of mining companies worldwide. As the in situ stresses concentrate around critical excavations, failure occurs at the excavation boundaries and ground support is required for the excavations to remain safe and accessible for their intended lifespan. Ground support consists of reinforcing elements that are installed within the rock mass to modify its internal behaviour (generally to within one excavation radius) and surface support elements that are installed at the exposed boundaries to retain the failed pieces of rock. For surface support to be effective, the loadings need to be transferred to the reinforcing elements; however, the combined performance of rock bolts and mesh is poorly understood in terms of the energy dissipation capacity available for a typical ground support scheme implemented at most mass mining operations.Over the last 15 years or so, a large number of large-scale laboratory experiments have been completed at the Western Australian School of Mines (WASM) Dynamic Test Facility for reinforcement systems and surface support systems loaded separately. The objective of more recent testing has been to establish the combined energy dissipation capacity of typical and enhanced reinforcement systems combined with mesh surface support. Total energy dissipation has been separated into energy dissipation attributable to the reinforcement and to the mesh. The results of the tests are presented and compared with the existing WASM design demand and capacity guidelines.CITATION:Villaescusa, E, De Zoysa, A, Player, J R and Thompson, A G, 2016. Dynamic testing of combined rock bolt and mesh schemes, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 789–798 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

Vitrinite reflectance forms the basis of a study of coal rank variation in two areas of the Upper Hunter Valley, New South Wales, on the northern margin of the Sydney Basin. A selective analysis procedure, based on samples rom twenty-two boreholes, has resulted in a small range of reflectance values for each sample and consequently a high degree of significance for calculated mean values. The patterns of rank distribution derived from these data have facilitated an interpretation of the rclative timing of coalilication and deformation in each area.This study provides support for the suggestion by several authors that there were at least two periods of folding in the tJpper Hunter Valley. In the Hebden-Ravensworth area, minor folding took place after most of the coalilication was completed.To the west, in the region of the Muswellbrook Anticline, coalification occurred during or after the formation of this major structure. Tectonic instability during deposition of the Singleton Super-Group, in the region of the Hunter-Thrust on the basin margin, is evidenced by rank variation suggesting differential subsidence across this zone.

Jan 1, 1980

By the use of flotation tests it was confirmed that there are two functions of oxygen in sulphide mineral flotation. Sized samples of galena and chalcopyrite were sulphidized, washed free of excess sulphide ion, and then contacted with air-saturated water for certain lengths of time. The mineral was then transferred to a sealed laboratory flotation cell containing water with a known concentration of dissolved oxygen. Xanthate and frother were added and flotation continued for 1 min.Both the extent of mineral oxidation and the concentration of dissolved oxygen markedly affected the flotation of galena and chalcopyrite. The response to a change in either variable is dependent on the level of the other, but generally best flotation occurs with the maximum degree of air saturation of the pulp. Galena flotation is hindered by oxidation of the mineral beyond a small threshold amount but a similar effect for chalcopyrite was not observed...

Jan 1, 1967

By S Vianna, K Caldwell, R Silva, T Olson, D Bell

Studies to enhance the FLSmidth forced air machine through changes in the design, showed important improvements through changes in the number of Rotor blades, stator designs, rotor air distribution and other designs features. The main outcomes from this study highlighted that increasing the number of rotor blades increased the selectivity while decreasing power requirements while stators with slots have better results in terms of recovery, flotation efficiency and selectivity than without slots.Also the rotor air distribution makes a difference in the design when comparing different distribution criteria whilst keeping all features of shape and number of blades etc constant. At the most efficient rotor air distribution design, copper recovery reached one of the highest values while keeping good selectivity. The possible explanation for that is the increase in the pump capacity indicated by the increase in the specific power.It was seen as significant that reduction in specific power for some designs tested compared with the then current standard design had an average of 30% less power consumption.As a result, FLSmidth was able to identify new designs that decreased power and improved recovery, as well as, identifying some designs that specifically improved fine and/or coarse particle recovery.CITATION:Silva, R, Caldwell, K, Bell, D, Olson, T and Vianna, S, 2013. FLSmidth flotation developments - Dorr Oliver machines, in Proceedings MetPlant 2013 , pp 413-430 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

The Acid Drainage Technology Initiative (ADTI) was initiated in 1995 by federal agencies, the National Mining Association (NMA) and the Interstate Mining Compact Commission (IMCC) to identify, evaluate and develop cost-effective and practical acid drainage technologies. In 1999, ADTI was expanded through the addition of the metal mining sector, which is focused on drainage quality issues related to metal mines. ADTI addresses drainage quality issues from abandoned, active, and future coal and metal mines. The guiding principle of ADTI is to build consensus among industry, federal and state regulatory agencies on acid drainage technology development and technology transfer issues. ADTI is focusing its efforts on mine drainage prediction, sampling/monitoring, modelling and avoidance/remediation. ADTI is not a regulatory or policy development program. ADTI includes the Coal Mining Sector (CMS) and the Metal Mining Sector (MMS) under the overall guidance of the ADTI Operations Committee. The Operations Committee consists of representatives from industry, state and federal government and academia. The Coal Mining Sector includes two committees; a prediction committee and an avoidance and remediation committee. The Metal Mining Sector includes steering committee and work groups on prediction, sampling and monitoring, modelling, mitigation, and pit lakes. The Coal Mining Sector has produced two publications on the prediction and prevention of acid drainage. The Metal Mining Sector has workbooks under preparation covering the work group topics. This past winter, the Metal Mining Sector, working with the US Bureau of Land Management, presented a satellite training session on acid drainage. ADTI has evolved in response to changing needs and technologies as evidenced by the addition of the Metal Mining Sector in 1999. The Operations Committee and the members of the Coal and Metal Mining Sectors will guide future direction in response to identified issues.

Jan 1, 2003

Computer applications are ideally suited to the day to day operations of grade control and short term planning on a mine site. By refining this part of the operation there is scope to increase profits by more accurately predicting ore grade and tonnage, and allowing the mining engineer more flexibility in his approach to scheduling. Large numbers of blasthole or ditchwitch samples need to be processed in a fast and efficient manner, and stored in a database for future reference. The mining engineer has to calculate tonnages and subdivide the blast or digging area into mineable areas of waste, low and high grade ore. New grade and tonnage information must be used by the mining engineer to update his short term plan. Answers must be obtained quickly and efficiently, but a high level of individual input is necessary in order that maximum use is made of the information. Geostatistical analysis of samples can be used to refine the interpolation techniques. Reconciliation between the original grade model, the newly sampled area, and the final product should be monitored continually.

Jan 1, 1989

By D Thorburn

This paper reviews the history of environmental assessment in New Zealand with reference to mineral developments. Emphasis is given to larger more controversial projects particularly metal mines. The changing role and application of the Environmental Protection and Enhancement Procedures is examined in the context of changes in the government's environmental administration and the response of the Ministry of Energy's resource allocation group. Conclusions are drawn on the effectiveness of the present environmental assessment activities and on the allocation of administration of priorities in the Ministry. The Ministry of Energy has effectively ceased to exist.

Jan 1, 1990

By C Dick

Over the past three decades, mining operations have seen a significant increase in the use of contractors for mining, camp management and catering, recruitment, maintenance, power management, and commissioning. More recently contractors have been engaged for stores and logistics, OH&S, environmental, exploration, training etc. In some countries, such as South Africa, the trend is towards total outsourcing of all aspects of a mining operation which is coordinated by the owners’ management team.During the Global Financial Crisis (GFC) more Australian companies considered and/or took on this approach to recruiting for both projects and operations as mining companies were forced to rethink their corporate strategies as commodity prices plummeted to low levels, pushing operations and projects into potentially financially unviable territory.This paper discusses the labour recruitment, commissioning and operating strategy of Western Areas NL (WSA), with the assistance of Independent Metallurgical Operations Pty Ltd (IMO), as it progressed construction, commissioning and operation of the Cosmic Boy nickel concentrator at the Forrestania Nickel Project during and post GFC. The use of IMO contractors allowed Western Areas to mitigate labour cost risk during the uncertainty caused by the GFC and let their management team focus on the task of bringing a new operation into viable and profitable production.

Aug 8, 2011

By Tumilty JA, Schmidt CG

Sulphide ion is a powerful poison in gold cyanidation, however, the detrimental effect is less severe in plant practice. This is thought to be due to the presence of depassivating elements in the ore, mainly lead. Trace amounts of lead can counteract the poisonous effect of considerable amounts of sulphide. The reaction is instantaneous and is likely to be a direct involvement in the electrochemical surface reaction. Lead addition cannot be regarded as an all-round cure when experiencing poor leach efficiencies. A possible beneficial effect depends on the mineralogy of the ore and has to be determined individually for every material.

Jan 1, 1989

During recent years there has been a marked increase in the use of explosives in Queensland coal mines. Delay detonators have been introduced and their use has extended with the wider application of mechanised methods of mining.The need for careful study of the characteristics of delay detonators is stressed so that the advantages of simultaneous firing, from the points of view of safety and efficiency, may be obtained. With their use new potential hazards are introduced. These hazardsare considered and means whereby the overall safety may be improved are discussed.The increase in the number of misfires since the introduction of delay detonators is shown and the examination of misfired detonators is described. Lessons to be learned! from these misfires are noted and details are given of the essential requirements for safe and efficient blasting using delay detonators.INTRonUCTIONOne of the aims of mechanization in coal mines is to reduce the physical effort applied to the winning of coal. Explosives play an important part in achieving this and, following the introduction of power borers for the drilling of shot-holes in Queensland coal mines, much of the arduous work associated with coal getting has been eased. During recent years there has been a marked increase in the consumption of explosives, as shown in Table 1, and it must be the aim of all to use these explosives safely and efficiently. That there are dangers associated with the use Of explosives cannot be denied. The shotfiring operation is fully covered by legislation and, being under the control of one man, shQuld be capable of being carried out with a high degree of safety. The main source of accident appears to be the failure to take proper cover and this has resulted in...

Jan 1, 1958

New Zealand has been a significant producer of gold for over a century. Total recorded production is over 850 tonnes. There were three major periods of production: the first and biggest was between 1860 and 1880, the second was between 1895 and 1920 and the third was between 1930 and 1945. After 1945 gold production fell continually until 1980 when the major upward adjustment in gold price led to renewed interest. There have been important new developments in each of the known gold-rich areas: Westland, Otago and Coromandel and exploration for gold in these areas and in previously unprospected regions has reached unprecedented levels.

Jan 1, 1988

THE method depends upon:--1. The position of the mill.2. The space available for stacking the residue.3. The nature of the residue as discharged from the mill.4. The value of the residue for re-treatment.5. The requirement of the residue for underground filling.Originally the conditions in this district varied mainly in the position of the mill, some mills having an elevated site with plenty of dumping space for the time being, whilst others had a flat site, and very little dumping space near at hand; but in most cases the residue discharged was in the form of filter-press cakes, suitable for conveying on belts, or in trucks, and stacking in a high clump; and, while a portion of the residue was used for underground filling, the dump was regarded as a valuable asset, to be re-treated later. Under these conditions, conveyor belts, electric trams, aerial trams, and hose trucks, all gave satisfactory results, and the following figures, taken from "'West Australian Metallurgical Practice," will show how these methods compared as regards costs...

Jan 1, 1909

In his account of the Thackaringa sulphide ore, Lawrence (p. 92) reports the presence of valleriite as a minor accessory in chalcopyrite. He says that it is readily identified by its intensive anisotrophy and reflection pleochroism. He also gives (p. 87) the chemical formula as Cu8Fe4S7 Recent work by Evans et al. (1964), Chamberlain and Delabio (1965), and Schidlowski and Otteman (1966) suggests that most material identified as valleriite is, in fact, mackinawite. Mackinawite and valleriite are both extremely anisotropic and strongly reflection pleochroic, and so with fine-grained material it would be hard to distinguish them optically.Mackinawite, according to Evans et al. (p. D66) is a copper-free iron sulphide (PeS) with small quantities of nickel, whereas valleriite is considered to be a dimorph of chalcopyrite (CuPeS2 ). They found that mackinawite is much more widespread than valleriite, and, unlike the latter mineral, is commonly included in other sulphides, particularly chalcopyrite.Lawrence (p. 92) states that the valleriite inclusions are up to 0·01 mm long, so that an electron probe microanalysis should be quite feasible and provide a ready answer to this query.L. J. Lawrence: I thank Dr Townend for his comments on the occurrence of a valleriite-like mineral embedded in chalcopyrite from Thackaringa. The problem of distinguishing valleriite from mackina...

Jan 1, 1967