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By Riley S. J

Ranger Uranium Mine is located within the Alligator Rivers Region of the Northern Territory of Australia and surrounded by the World Heritage listed Kakadu National Park (Figure 1). The mining operation is currently producing about 1500 tonnes of uranium oxide annually, as well as considerable volumes of waste rock, low grade ore and tailings. The rehabilitation of the project should ensure that the radioactive mill tailings and other contaminants remain contained for at least 200 years, as required by the existing guidelines (Commonwealth of Australia, 1987). The present uranium mining operation is regulated by the Northern Territory Department of Mines and Energy who must refer to the Environmental Requirements when considering regulatory options. These Environmental Requirements were agreed by the

Jan 1, 1994

Over years of exploration the massive and tabular orebodies in the area to the South West of Western Areas Gold Mine had been assessed as containing about 50 million ounces of gold û a world class orebody. Planning initially was for a surface and subvertical shaft system to exploit this area but because of cost, a single lift shaft to an area which could be accessed ex Western Areas was planned to intersect the reef at 2760 metres. It was also planned to mine out the shaft pillar area long before the deep shafts would reach that position. This is not the normal practice in South African Gold Mines. The stoped out shaft pillar was backfilled to minimise movement in the shaft sites. The result of a competitive tender/adjudication process was that Cementation Mining û Skanska won and was awarded the R192 million contract to sink the Main and Ventilation Shafts on 15 June 1995. On 1 April 1999 Western Areas and Placer Dome SA formed a Joint Venture, which now owns and operates the mine on which the South Deep Shafts are situated. This situation prevails today.

Jan 1, 2002

By O Aydan, K Sugiura, A Sakamoto

It is well known that some sinkholes or subsidence take place from time to time in the areas where abandoned room and pillar type mines exist. The authors have been involved with the stability of abandoned mines beneath urbanized residential areas in Tokai region and there is a great concern about the stability of these abandoned mines during large earthquakes as well as in long term. The 2003 Miyagi Hokubu and 2011 Great East Japan earthquakes caused great damage to abandoned mines and resulted in many collapses. Particularly the effect of the quality of backfilling of abandoned mine below the urbanized areas is very important under static and dynamic conditions. The authors present the effect of the quality of backfilling on the ground subsidence associated with abandoned lignite mines under static and dynamic conditions and discuss its implications on the urbanized areas above abandoned lignite mines in this study. CITATION:Aydan, O, Sugiura, K and Sakamoto, A, 2018. The quality of backfilling of abandoned lignite mines on ground settlement under static and dynamic conditions, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 134–141 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By H Ramandi, H Masoumi, I Canbulat, B Hebblewhite, J Oh, S Saydam, W Timms, S Mo

This paper reviews the floor heave mechanisms in underground coal mine roadways. Previous studies have reported three main failure mechanisms: bearing capacity failure, buckling and swelling. The buckling failure has been observed where immediate floor strata are relatively strong and thinly bedded. On the contrary, the weak floor strata have been associated with both the bearing capacity failure and swelling mechanisms. The bearing capacity floor failures are likely to induce other types of instability such as pillar punching, tensile failure of pillar, roof fall and subsidence as well as floor heave. Despite a considerable amount of research, predicting the magnitude, location and timing of floor deformation is challenging with current state of knowledge. CITATION:Mo, S, Ramandi, H, Oh, J, Masoumi, H, Timms, W, Canbulat, I, Hebblewhite, B and Saydam, S, 2018. A review of floor heave mechanisms in underground coal mine roadways, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 196–206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By Tack K

During its 28-year life the MHD ISP smelter has gone through two phases, each of about a dozen years. The first phase was a learning one; in the second phase the lessons were applied and throughput and production rose strongly. Early experience revealed the robustness and the flexibility of the Imperial Smelting Process. The experience was demonstrated by strong increases in the throughput of mixed lead-zinc concentrates and of secondary (oxide) zinc materials. Purchased material quantities rose from 175 000 tonnes/year to 200 000. The required capacity increase of the IS furnace to smelt the higher throughput was achieved by relatively minor modifications; for instance a change to the internal furnace profile gained an extra two square metres in cross sectional area. The furnace hearth area has remained practically unchanged over its entire history. The paper concludes that there is still more potential to be drawn from the process and MHD intends to sustain raw material input at a new level of 240 000 tonnes/year. However, this rate will have to be achieved under the imposition of more stringent environmental and product quality standards than ever before.

Jan 1, 1993

Commissioning is one of the many phases of a project, it has inter-dependencies with the other phases, as they have amongst themselves, and has its own terminology and distinctive features. Commissioning time and cost can severely affect project economics, especially through unrealistic estimating, and requires a separate management team to ensure full control is. maintained. Targets to be achieved in commissioning are identified, together with the necessary policies to achieve them. Factors which have to be taken into account in applying these policies are Discussed.

Jan 1, 1986

By R F. G Phelps

The former Gwynfynydd gold mine is located within the heart of the Snowdonia National Park, North Wales, United Kingdom. The black shale-hosted quartz reefs have intermittently produced more than 50 000 ounces of gold since 1863. Its most recent period of operation by Welsh Gold PLC was between 1992 and 1999 when it extracted 10 000 tonnes annually from a total resource base of 180 000 tonnes. A historical mining grade of 15 grammes/tonne was recovered from the Chidlaw Reef on which all production was based. Erratically distributed gold pockets hosted in the footwall zone of a 3 - 6 m wide quartz reef characterise the mineralisation. The gold exhibits a high-nugget effect and as a consequence the accurate determination of tonnage and grade was difficult. Production was undertaken by overhand shrinkage stoping. Due to its location within a National Park certain environmental constraints were placed on the operators. The principal requirement of planning permission was that processing should take place above ground and not involve chemicals. As a result, an underground mill based on physical separation methods was constructed in response to these environmental constraints. Much of the mine discharge is related to the flow of rainwater through the workings from surface openings on the reefs. Discharge from the underground milling facility was enhanced in various metals, particularly zinc, though was reduced to legally acceptable levels using liming tanks prior to discharge into the River Mawddach. The company was required to monitor and treat all water discharged from the mine before it reached the river. The mine closed in 1999, since which time a tip re-processing has continued as part of an environmental remediation and gold supply program.

Jan 1, 2002

By Grady B. V O, Cavell K. J, Ault A. R, Newman O. M G, Malcolm J. McPhersqn

Cyclic voltammetry (CV) has been evaluated as a technique for monitoring the quality of an industrial zinc sulphate electrolyte. The basis of the method involves measuring a change in the polarisation of the zinc nucleation reaction at an aluminium surface and relating this to the impurity content and/or the overall quality of the electrolyte. Specifically, the technique aims to be able to indicate and quantify detrimental synergism between impurity elements, something which traditional analytical techniques are incapable of providing. The technique has found some success with regard to monitoring glue additions in a range of metal electrolytes. It has been found that investigations by a number of workers over the past 15 years have produced variable and often misleading results due to the inadvertent use of commercial purity aluminium working electrodes. It has been shown that impurity elements in the working electrode can give rise to a range of responses that are not obtained when pure aluminium is used and that the response is variable due to the lack of surface homogeneity of commercial purity aluminium electrodes. Furthermore, it was demonstrated that previous detection limits reported in the literature were based on the presence of additional peaks in the cathodic scan and not polarisation effects. The results of this study have shown that when a pure aluminium working electrode was used, the method was incapable of detecting any change in polarisation for an electrolyte containing three common impurities (Co, Ni and Ge), at concentrations that would significantly reduce optimum electrolytic performance. A range of methods was tried to sensitise the technique, including raising the temperature and acidity, and adding antimony in order to induce some synergism. In all cases the polarisation response was unchanged. Consequently, apart from the commercialised application for monitoring additions of antimony and levelling agents such as glue, CV has very limited application as an electrolyte screening technique.

Jan 1, 1993

By J. K. A. McLEOD

Address by the President of the Institute (Mr J K A McLeod) in presenting the Institute Medal to Howard Knox Warner, C.B.E. Address by Howard Knox Warner after accepting the award.

Jan 1, 1978

By J Harris, P Kirsch, R LaBouchardiere

æMining + Health in DevelopmentÆ is a project funded by the International Mining for Development Centre (IM4DC, 2012) to develop a centralised database of corporate sustainability initiatives for managing and improving occupational and public health, based on information extracted from social and environmental reports of major mining, oil and gas (MOG) companies. This register of materials has the potential to increase stakeholder awareness of the unique health risks impacting the minerals industry, employees, their families and surrounding communities, as well as to inform stakeholders on global industry approaches to health management.Data and preliminary outcomes from analysis of different MOG corporate sustainability reports on public health and disease management are presented for six African countries (Democratic Republic of Congo, Ghana, Mozambique, Sudan, Tanzania and Zimbabwe) and six Asia-Pacific countries (Indonesia, Mongolia, Pakistan, Papua New Guinea, Philippines and Vietnam).With the minerals industry facing ongoing rapid growth worldwide, including continuous expansion into developing regions, the æMining+Health in DevelopmentÆ project will inform industry, civil society and regulators of current health management practices and programming among the different sectors of the minerals, oil and gas industries and across various regional operations. This baseline information will serve as a resource for minerals industry managers, providing a forum for sharing best practice health management approaches amongst MOG companies.CITATION:LaBouchardiere, R, Harris, J and Kirsch, P, 2012. Mining and health in development - An inventory of global resource industry health initiatives in developing countries, in Proceedings International Mine Management 2012, pp 75-90 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

Getting it right is a very profitable outcome. Shareholders would ideally like to see their directors get it right all the time on the major economic decisions. But it is very difficult for mining directors to get it right all the time in such an uncertain environment. Primary decision-makers of companies with significant stakes in the mining industry should get it right much more frequently. The legal measures of evidence (beyond reasonable doubt and on the balance of probabilities) can be used to determine whether grade estimates (a key revenue variable) are realistic. The application of this approach can be far reaching. More frequently correct decision-making would result in more effective allocation of limited resources (capital and labour). In turn, this would result in higher financial returns and a more extensive mining industry.

Jan 1, 1994

Government established and financed the NZ Steel Investigating Co in 1960. Its investigations showed that a steel industry was feasible and desirable based uponNorth Island titanomagnetite ironsands, and charted a route for its establishment. The initial processing used post-1945 preheating and prereduction developments, but later innovative improvements created what was essentially a new New Zealand technology. Of the North Island titanomagnetite deposits: the small ones at Waipipi were best made available for export; those at Kawhia and Taharoa were too remote for the economic siting of a mill; that at Raglan proved too small; while at Waikato North Head three times the requirement of 50 million tons of concentrate were located in two sand areas averaging 18 per cent titanomagnetite. Economic studies showed that a South Auckland site would be ideal, close to New Zealand's biggest market. The mill site, on a basalt flow at Glenbrook, was located by a half-day's fieldwork - near both the Waikato North Head deposit, and a railhead for bringing in Waikato coal, etc, and taking out steel products.   This development was one of several since World War II which altered significantly the lives and homes of New Zealanders (others were natural gas, oil, geothermal power, epithermal gold, aluminium, opencastable lignite, etc). All had the essential ingredients of the highest government backing, direct or indirect government finance, and first-class New Zealand scientific and engineering skills (eg to create new technologies). Not one such project failed.

Jan 1, 1993

By Z Lubosik, S Prusek, M Plonka, B Syrek

"The most commonly used method of thick coal seam extraction in Polish deep mines is multislice longwall (MSL). In MSL stability of goaf in the roof as a result of previous extraction in upper slice is a major geotechnical consideration that must be managed.This paper outlines the results of a wide range of investigations carried out in three longwalls that were in operation in a multislice system using caving with additional fly ash goaf stowing. The longwalls were operated by Katowicki Holding Weglowy SA (KHWSA) in the Upper Silesian Coal Basin of Poland.Examinations were completed on the properties of goaf at the roof of longwalls ie measurements of strength parameters of the goaf material by means of a borehole hydraulic penetrometer, determination of the goaf condition by means of a borehole endoscope and laboratory testing of the caved rock. The results of underground examinations of the loading on yielding arches in the gate roads associated with these longwalls and measurements of vertical and horizontal convergence are also presented.CITATION:Prusek, S, Lubosik, Z, Plonka, M and Syrek, B, 2014. Multislice longwalling for thick seam extraction – properties of goaf in the roof and gate roads behaviour, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference, pp 359–366 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 5, 2014

The perception of New Zealand as an exploration destination has improved compared with other countries. There has been a realisation that New Zealand's potential is greater than previously thought. Other countries are not as attractive as before, and explorers are looking at alternatives that are geologically prospective and politically stable.   New Zealand is regarded as geologically prospective, especially for gold, with potential for world class deposits. It is also prospective for other metals, coal and industrial minerals. New Zealand is politically stable, and has an economy that is attractive to overseas investors. It is one of the least corrupt countries in the world, which overseas companies see as providing a high degree of certainty for investment.   New Zealand has good opportunities for investment in gold exploration at present. Otago has been the focus for new companies and is the favoured exploration location. Otago is regarded as very prospective, and hosts New Zealand's largest gold deposit at Macraes. There is potential for other similar deposits elsewhere in Otago.   The mineral industry previously had an excessively pessimistic view of New Zealand, which has resulted in little new investment in New Zealand for some years. Previous pessimism is turning to optimism, and there is increasing interest in New Zealand as an exploration destination by overseas explorers.

Jan 1, 1997

Sophisticated pit optimisation software has allowed mine planning engineers to generate mining outlines that consider the numerous factors that have a major effect on the success or otherwise of a mine plan. The outlines are generally generated using a range of values for which one can assume a fixed mining cost and a variable revenue. During analysis, the expected costs and revenues are used to investigate the cashflow and sensitivities. Ultimately, the final pit and incremental outlines, or shells, are selected for a given expected price. This paper proposes an alternative method for incremental pit shell selection that considers the risk the mine be prepared to accept. The life of mine is divided into a number of Business Risk Periods (BRPs). The BRP represents the period of time over which the owner is prepared to invest capital. During each BRP, the mine will then operate at a selected investment cost which is generally equal to or greater than the minimum required to meet production targets. In this way, a robust mine plan can be produced which allows the mine to react to change without having to alter the incremental shell limits while maintaining a strategic risk profile. This paper will summarise factors to be considered in selection of the BRP and the incremental pit shells within the BRP.

Jan 1, 1998

This is the seventh major symposium organised by Illawarra Branch over the past five years and the fifth dealing with various aspects of coal. It is clear that all of you here need no convincing that black is beautiful! This symposium is on a broader canvas, covering the overall field of occurrence, preparation and utilization of black coal throughout Australia. It is thus the most comprehensive treatment of the subject by the Institute since the symposium organized in 1950 by the Sydney Branch with the co-operation of the then newly formed branches in Newcastle, Illawarra, Central Western N.S.W. and Southern Queensland, all of which shared coal as a major interest. The 1950 symposium was adopted as a volume in the series of seven published by the Fifth Empire Mining and Metallurgical Congress in 1953. This historical reminiscence brings to our minds the circumstances in which these new Institute branches were formed. This happened in the year of the presidency of the late Frank Hockey, and at the time the Australian black coal industry was in many ways at a very low ebb. It was the time of extreme shortage of coal following World War II, and the industry was beset by industrial unrest on such a scale that daily bulletins were posted listing the number of idle pits, of idle miners and of tons of lost production. There could not, of course, be any thought of export marketing. Some of the more picturesque bulletins recorded the number of pits at which the ceremonial emptying of billies took place, and the number of pits at which the aroma of the horses' breath was insupportable. At an Institute conference at the time it is on record that the late lamented Austin Edwards, that tireless mineral researcher, author and editor, in his gentle way chided the personnel of the industry and the members of the Institute for having allowed a situation to develop in which a whole generation of Australian children could grow up without ever having seen coal or knowing what it was. It is sad that most children and most Australians have still never seen coal, and think of it as something dirty and uninteresting. The desperate situation of the black coal industry inspired moves by people in industry and in governments, whose plans and efforts have been recorded elsewhere, to modernize coal mining methods, to introduce coal preparation, and generally to restore the mines and the mining communities and to re-cast the steel industry and electricity generation. Amelioration of the traditionally troubled industrial relations was an integral part of this overall programme, and whilst one would wish this aspect had progressed further the situation has, in fact, improved immensely. New investment in exploration, mining, preparation, transport and utilization both by the existing coal mining groups and by new entrants, Australian and overseas, have played a large part in bringing about the transformation of the industry to such a point that Australian needs are being fully met and a large export market is being supplied - a situation that few would have dared to hope for in those dark post-war days. Forecasts of exports from New South Wales and Queensland show coal becoming a dominant foreign exchange earner for an indefinite term. Old King Cole may have vanished from our children's nursery rhymes but King Coal is here to stay, providingthat costs in the industry can be kept within competitive limits. It is all too easy for an industry to price itself out of the export market by inflation, by increased costs for a variety of reasons, and through currency readjustments. A second proviso is that we must continue to encourage a balanced attitude to environmental matters.

Jan 1, 1975

By B Muller

The disposal of tailings has become a greater issue due to the changing economics of mineral extraction. The processing of lower grade deposits and tougher environmental regulations has led to the selection process for tailings disposal options becoming more complicated. Current selection methods are too time consuming or too easily manipulated for inexperienced users to use successfully. This paper examines a different method for the initial selection of a tailings disposal system, using a numerical system that was introduced into the mining method selection field. The numerical method system was compiled by reviewing previous work done on the positive and negative aspects of the tailings disposal methods used by the coal and metallurgical mining industries. Assessing the common trends and design aspects of each of the methods was undertaken and a ranking was designed to explain how well suited the tailings disposal methods are to a situation. The tool successfully analysed sites using common data to indicate methods for disposal that would have provided minimal technical problems, low environmental risk and been practically possible. The tool also proved successful in identifying critical areas that would need further investigation. This new system was tested on some disaster case studies from around the world in order to show that it could have successfully selected a different method for tailings disposal that would have prevented the disaster.

Sep 26, 2011

By Glasson K. R

The history of Ore Reserve classification and reporting in Australia is largely a history of the Australian mining industry itself. In the late 1800s, when the industry was dominated by small scale, high grade underground mines, Reserves (if estimated) were based on hand sampling and geological inference, and reporting of Reserves was either non-existent or of extremely variable quality. By the mid-20th century, the industry was dominated by large underground base metal and gold mines. Reserve estimation was coming under the control of skilled geologists and mining engineers, however Reserve classification and reporting standards continued to vary in type and quality from mine to mine. Today, large scale, low grade mining operations predominate, and Reserve estimates are generally based on extensive drilling results processed (with geological control) by computer. Through the efforts of a Joint Committee established by The Australasian Institute of Mining and Metallurgy and Australian Mining Industry Council, Reserve and Resource classification and public reporting has been standardised and controlled by adoption of the ""Australasian Code for the Reporting of Identified Mineral Resources and Ore Reserves"" released in 1989. The Code, which will continue to be modified and improved by the Joint Committee, has also been used as a basis for guides to reporting in other countries, and there is now some hope that this difficult and vexing topic may finally become subject to international standards and controls.

Jan 1, 1992

By J R BISHOP

Geophysical techniques are being increasingly used down exploration drill holes as deeper and more elusive targets are sought. This paper lists the various methods available and discusses the applications using a number of examples.

Jan 1, 1992

By M Araos, I Onederra

A novel explosive formulation that substitutes the use of ammonium nitrate (AN) with hydrogen peroxide (HP) as the main oxidising agent has been developed and tested as part of an Australian Coal Industry Research Program (ACARP) project. The main objective was to provide a step-change solution that has the potential to completely eliminate NOx fumes in blasting. The development of this HP/fuel-based explosive started with a comprehensive detonation characterisation program, consisting of unconfined velocity of detonation (VOD) measurements of samples at different diameters, densities and void sensitisation techniques. VOD results showed that the HP/fuel-based explosive mixtures behaved similarly to non-ideal commercial explosives; in that way mixtures could be tailored to achieve specific detonation performance targets. The next stage of testing in this development involved preliminary confined tests to evaluate the rock breakage potential of the HP/fuel-based explosive mixtures. Fully instrumented single-hole tests were conducted in a limestone quarry. Results from these preliminary trials confirmed the rock breakage performance of HP/fuel-based explosive mixtures. The confined VOD measured in one of the tests was 5100 m/s in a 102 mm diameter blasthole at a density of 0.96 g/ml. The corresponding borehole pressure measurement of this HP charge was 2.61 GPa with a detonation temperature of 2921°C. Based on near-field accelerations, both HP and ANFO charges displayed similar attenuation characteristics in the test conditions. Post-blast observations indicated that the breakage performance of the HP mixtures clearly reflected the in-hole detonation performance measurements obtained, confirming the ability of these explosive mixtures to both fragment and effectively displace the rock mass under evaluation. Further research work continues with the future commissioning of a prototype mixing and delivery unit, the successful completion and analysis of data from multiple-hole trials, and further characterisation work associated with product stability, reliability and performance under different geotechnical conditions.CITATION:Onederra, I and Araos, M, 2015. Detonation and breakage performance of a hydrogen peroxide-based explosive formulation, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 565–574 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015