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Difficult ground conditions in the area planned for placement of vent rises to the surface at the Porgera Goldmine led engineers directing the project to chose blind shaft boring methods of shaft construction from the available alternatives. Zeni Drilling Pty Ltd was first contracted in 1988 to install a group of three closely-spaced, steel lined shafts. The success of these led to an order for a fourth hole in the same group followed by two more, less than a kilometre. away, under a separate contract in 1992. All of the shafts were completed on.schedule to within one day. The only significant difficulty arose during commencement of the last shaft when the strata collapsed trapping the drilling tools and jeopardising the stability of the surface collar pad. The situation was corrected by innovative lining techniques and the project went on to finish on schedule. This paper discusses the application of various technologies associated with the project including aspects of geotechnical input, drilling fluid chemistry, mining engineering and logistics.

Jan 1, 1993

It is difficult with inadvertent explosions to establish fundamental data, especially of original dust, of pressure, temperature etc. and of ventilation oscillations, as exposed personnel rarely survive. Retrospective data from explosions must be derived from damage, from fatalities, from ventilation analyses, from analyses of dusts and other indications of temp- erature and duration of temperature. The five disastrous explosions selected for analysis provide examples of what data can be established as to the cause and extent of explosions. Such information is required for legal etc., inquiries subsequent to explosions, but most importantly to give the best guidance for avoidance of possibility of further Disasters.

Jan 1, 1981

By D C. Verdon-Kidd, G R. Hancock, M J. Saynor, J B. C Lowry, T J. Coulthard

Designing post-mining landscapes requires quantifying the short and long-term risks. In recent years, computer based landscape evolution models (LEMs) have been used to provide insight into both erosion rates and processes (i.e. sheetwash, rill, gully erosion). An important requirement of these models is high quality model input parameter data, which includes both the surface material (i.e. soil and waste rock) and climate information. However, in many cases such data is limited and in the case of climate information, the data is often short and incomplete. Here we develop climate scenarios and examine different surface material properties using a case study at the ERA Ranger mine located in the Northern Territory, Australia Firstly we develop scenarios that represent the range of future climates that may be experienced at the site. Secondly we develop a series of plausible particle size distributions based on a large sampling exercise of the waste rock material. We then test the sensitivity of different rainfall sequences and surface materials on sediment output using a well-tested landscape evolution and sediment transport model (Hancock et al., 2017). CITATION:Hancock, G R, Verdon-Kidd, D C, Coulthard, T J, Lowry, J B C and Saynor, M J, 2018. Quantifying the effect of climate and surface materials on post-mining landscape erosion – a risk approach using landscape evolution models, in Proceedings Life-of-Mine 2018, pp 122–124 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

Pipe Jacking has been a recognised method of tunnelling in the U.K. since the early 1950's, although I understand that pipes were pushed blind by the soldiers in the first World War from trenches on the Allied side to, or adjacent to, trenches on the German side, thus allowing explosives to be used with a certain element of surprise! 'However, on its more conventional to the U.K. in the 1950's, Pipe Jacking made considerable inroads into the tunnelling market place as an alternative to timber supported headings. This success was, unfortunately, fairly short lived because, owing to its simple method of operation, contractors paid insufficient detail to the engineering (or surveying) aspects and as such the system soon had a bad reputation for unreliability and lack of accuracy. Due to these failings, the market was not exploited and, therefore, there was a lack of investment by contractors, pipe manufacturers and also by any client, or research organisation, which is client associated. The effect of this meant that the system stagnated for a number of years and was used generally only for short crossing work (i.e. railways, canals and motorways), and then only in good homogeneous ground. Albeit, a limited number of full scale sewage disposal contracts were carried out, but with the lack of knowledge and experience of the clients, contractors and suppliers, (particularly the pipe suppliers), no reasonable success, either physical or financial, was achieved on any such contract.

Jan 1, 1987

By N Elith

The explosives demolition of a post-stressed, steel reinforced, concrete road bridge in Australia’s capital city, Canberra. The bridge was 50 m from the new replacement bridge, 320 m from community structures and within five kilometres of the national parliament buildings. The job required multiple overlays of risk assessment, public relations, safe work procedures, specialised blast design, environmental predictions and flyrock controls. Project stakeholders included Worksafe, Roads ACT, bridge owners, consulting structural engineers, community groups and road users. The bridge precincts, including a major road underneath, had to remain operational to peak traffic in the days leading up to the demolition. The break-up and removal of debris had to be executed in just two days from Friday to have the road beneath re-opened for Monday morning city-bound traffic.In Canberra, all explosives demolitions are now viewed with particular caution after a demolition in 1997, during which a young girl was killed. Any approval requires that Explosives Regulations, AS2187 2006 and Worksafe processes are satisfied, and a convincing case presented for blasting as a safe and viable option.Our design used specialised shaped cutting and blasting charges to sever in situ concrete beams and tendons and to shatter components of the stressed concrete bridge assembly. We include comments on structural engineering reports dealing with pre-weakening mechanisms. The benefit of pre-weakening is that it reduces the amount of explosives needed to safely complete the job and facilitates quick removal of debris after the shot. The complementary skills of the team, each one an expert in his field, resulted in a highly successful demolition, praised by authorities as an outstanding example of controlled use of explosives.

Nov 8, 2011

By S Azam

Coal is a vital energy source and source of carbon for metallurgical applications, contributing significantly to the world economy. Coal mining and processing involve multiple processes that generate Respirable Coal Mine Dust (RCMD), one of the primary sources of health hazards for coal workers. Since 2000, the rate of Coal Workers’ Pneumoconiosis (CWP) has continually increased in the U.S, with severity of the cases also worsening. Increasing evidence shows that exposure to RCMD in coal workers is a high-risk factor for lung cancer, which causes more deaths than the following three major cancers combined in the US Recent observations show an increased incidenceof CWP or other lung diseases, particularly among young miners in the Appalachian basin. The CWP prevalence in Appalachia is four times higher than the national average. Although various regulations are in place, the resurgence of such disease among coalminers demands additional efforts to better understand all the possible facets of coal dust toxicity, taking insights from current interdisciplinaryresearch efforts. One such important field is the interaction of coal dust with moisture in underground mines. Although moisture is prevalent and dynamic in an underground mining environment, it has never been evaluated for its impact on modifying the toxicity of coal dust and transport or flow behaviour. However, research conducted in atmospheric sciences in the past decade makes it clear that moisture in the atmosphere can significantly alter the behaviour of mineral dust. This paper is a part of research aimed at understanding how moisture interacts and alters the characteristics of coal dust. Such insight is crucial in understanding the potential toxicity of coal dust and developing mitigation technologies.

Oct 12, 2022

By Zamel G. I, Zenari L. P

Technological developments in modem Tunnel Boring Machines (TBMs) and associated back-up equipment are offering significant alternatives for mining operators to consider, in the selection of equipment for coal mine development drifts, roadways, longwall gate roads as well as metalliferous mining declines and development drives.Greater flexibility in handling variable ground conditions, muck disposal and radius of turn as well as advance rates, are just some of the areas where modem TBMs can accomplish the flexibility that mine operators require to achieve cost-effective developments.Compact TBMs are achieving this acceptance because of the fundamental design of a shielded machine containing electrics and hydraulics within the forward shell, ability to achieve tight radius of curvature and grades, and ability to provide highly flexible support systems to meet all possible ground conditions.However, a single TBM design will not suit all mine developments, as each development method - while having common goals with all mine developments - will also require certain unique criteria to be fulfilled.

Jan 1, 1993

By Mostyn G

In the last three decades various theories have been presented to allow the estimation of the force required to cut rock. These have generally relied on an hypothesised mechanism of chip formation.The paper presents results of an experimental program completed on an unjointed artificial rock in which the force and chip geometry were measured during deep cutting with a quarter scale bulldozer tyne. The program included various depths of cut and artificial rock of varying strength. The experimental results are compared with predictions based on three expressions for cutting force. Generally the measured forces are within the range of those predicted but none of the methods predicts the cutting force with any accuracy. It is considered that the discrepancies are due, in part, to the fact the that actual shape of the chip formed in deep cutting is quite different to that assumed in developing the theories and thus the theories cannot be expected to predict the cutting forces. It is concluded that Evans and Nishimatsu's theories predict lower bound estimates of the horizontal cutting forces. Deliac and Fairhurst's approach appears to over estimate the forces required to cut rock. New methods of prediction are required based on the observed mechanisms of failure.

Jan 1, 1993

Excessive use of computers in teaching, especially in self-learning programs, may destroy creativity and initiative. It is essential that engineers remain innovative to develop new technology. Safety legislation may have hindered the Development of mine managers. It may be necessary to develop two distinct streams of mining engineers. One should be biased towards human relations and safety, to 'be a certificated mine manager, and the other should be mathematically based as a high-technology mining engineer who would not necessarily qualify for a certificate of competency without a postgraduate course.

Jan 1, 1986

The Illawarra Branch of the Australasian Institute of Mining and Metallurgy over recent years has established an enviable reputation for organising and conducting conferences, colloquia and symposia. And this Symposium must surely enhance that reputation. The subject of the Symposium, Seam Gas Drainage has become a matter of great import- ance to the Australian Coal Industry in a comparatively short time. Our short experience being due to our operations, until recent times anyway, not being unduly affected by gas. The Australian Industry, by virtue of its mines getting deeper and higher rates of extraction being required is now encountering the difficulties with gas which have for so long been part of the coal mining scene in many other countries. Because these gas emissions affect our working conditions by way of creating hazards and affect our production by way of bringing about cessation of operations from time to time this Symposium must be regarded as being very timely out here. I must congratulate the Branch Committee on the general set,yp :o.f the programme of papers. The classification of papers into four groups and the sequence in which the papers were presented provided an excellent flow through from introduction to finality. It is not my intention to further discuss individual papers - already they have been well discussed in this forum and as I understand it outside in the early hours of the morning,

Jan 1, 1982

By W Y. Kim, Y B. Kang, Y J. Park

The phase equilibria in the Al2O3–TiOx system were investigated in wide ranges of temperature and oxygen partial pressure: 1300~1600°C and 10-16.6~10-8 atm, respectively. The equilibrium phases and their compositions were identified using X-ray diffraction (XRD) and electron probe microanalysis (EPMA), respectively. Most noticeably, a wide range of pseudobrookite solid solution was found in equilibrium with almost pure alumina. At each temperature, the cationic ratio expressed as RTi = nTi/(nAl + nTi)) of the pseudobrookite solid solution showed a noteworthy dependency on the oxygen partial pressure. This resulted in the formation of a broad range of pseudobrookite solid solutions, ranging from Al2TiO5 (RTi = 1/3) to Ti3O5 (RTi = 1.0). Complete miscibility within the pseudobrookite solid solution was observed at 1600°C, with only a minor miscibility gap becoming evident below 1500°C. Based on the results obtained in the present study, the behaviours of Al2TiO5 pseudobrookite have implications in two key domains: (1) understanding changes in the physical properties of the materials, and (2) elucidating the evolution of Al–Ti complex oxide inclusions in liquid steel which can deteriorate the steel cleanliness.

Aug 21, 2024

An empirical kinetic model is discussed that enables the number of stages in a carbon-in-pulp plant and the amount of carbon in each stage to be calculated for any desired metallurgical performance. It is shown that a knowledge of the kinetics of gold extraction by activated carbon in each stage assists plant operators in the important' areas of process control and optimization. Factors such as mixing efficiency, concentration and distribution of carbon through the plant, bypassing of pulp through a stage, and carbon poisoning are examined. The resin-in-pulp process for the extraction of gold cyanide is also discussed, and the chemistry of absorption and elution on strong- and weak-base resins is examined. In addition, operating results from a small-scale resin-in-pulp pilot plant are presented, and various applications in which resin-in-pulp may be preferable to carbon-in-pulp are discussed.

Jan 1, 1982

By Han Kook-Nam, Lawson F

The recoveries of the three cobalt minerals in the Mount Cobalt deposit, cobaltite CoAsS, erythrite CO3(AS04)8H20, and new cobalt mineral with a composition approximating 2CoO.CaO.Fe203.2As205.11H2O were investigated using physical and surface-chemical processes.Over 80 per cent cobalt recovery was achieved by tabling a cobaltite-mineralized sample, while about 76 per cent cobalt recovery was obtained by dry feed magnetic separation of a sample containing erythrite and the new cobalt mineral. The resultant primary magnetic concentrate with a cobalt grade of 5.5 per cent, was able to be upgraded to 14.4 per cent cobalt by regrinding .and a further magnetic separation.Electrophoretic mobility - pH responses for each of the three cobalt minerals were found to be similar. Each mineral remained negative over the pH range 3 to 11 and was most negative at mildly alkaline pH values.Cobaltite was floated effectively with amyl and ethyl xanthate collectors under acidic conditions at collector concentrations of 10-2M to 10-5M. Erythrite showed a similar flotation response using 10-sM amyl xanthate. The practical application of these laboratory separations to an industrial process is suggested.

Jan 1, 1976

By Tomlinson E, Lama RD

Drainage of gas has been practiced overseas for almost half a century. Peal advances in drainage of gas to combat high emissions became practicable in the late fifties and early sixties when the technology was standardised to use it under a variety of mining and geological conditions. Today methane drainage is practiced in the United Kingdom, Germany, France, Belgium, Poland, Czechoslovakia, Hungary, Ibmania, U.S.S.R., China, Japan, Canada, U.S.A. and Mexico. Australia entered the list of countries using gas drainage on 3rd March, 1980 when the first full scale gas drainage system was set up and commissioned at West Cliff Colliery to drain gas from the Bulli Seam. Methods used in Europe are different from those used in North America, Japan and Australia mainly because of the different mining methods and also because of the limited number of seams under extraction, relatively new coal fields, and comparatively larger distance between the seams. In spite of the difference in the technique, the basic aim is the same and that is to improve ventilation and reduce ventilation costs, alleviate dangerous gas accummulation, overcome outburst hazards and ultimately make mining safer and more efficient. Over the last decade, there has

Jan 1, 1982

By E R. Ramanaidou, C Tessarolo, M Verrall

Garnierite mineralogy in saprolitic ore of the Goro lateritic nickel deposit, New Caledonia , was investigated using X-ray diffraction (XRD), optical and scanning electron microscopy (SEM) and electron microprobe (EMP) analyses. These conspicuously, green-coloured phases occur either as submillimetre to centimetresized veins or as æbookletsÆ arranged in, macroscopic (subcentimetre sized), accordionlike structures supported in an undifferentiated matrix of mixed ÿ7+ and ÿ10+ phases. Within the veins, nickel for Mg solid solution increased from ten wt per cent NiO at the edge to 34 wt per cent NiO at the core, with vein edges comprising Ni-kerolite with <1.5 Ni per formula unit (pfu) grading to pimelite containing >1.5 Ni pfu at vein cores. The æbookletsÆ comprised nTpouite of formula, (Mg0.67Ni1.59Fe3+0.05)(Si2.17Al0.22)O5(OH)4 and averaged 30 per cent NiO. SEM element mapping highlighted the distribution and mineralogical association of Ni and Mg and emphasised the inverse relationship between Ni and Mg at the macroscopic (thin-section) scale. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By L Bertoss, D Carvalho

In the last decade, the use of advanced implicit modelling software/algorithms in mineral resource workflows has become a best practice in the mining industry. In most cases, these workflows can easily replicate the level of detail of explicitly modelled geometries, even for very complex deposits. These techniques are flexible and can produce fast results since software is responsible for generating 3D surfaces and solids based on geological and interpretation data. Nevertheless, depending on how unique and complex some deposits are, intense manual editing and input are required to honour the geological context and produce the desired outcome. The current geological modelling workflow at George Fisher Mine (GFM) is based on the semi-automatic built-in tool that generates stratigraphic sequences (stacked lithology layers) based on logging and mapping data. This tool (stratigraphic sequence from Leapfrog Geo™) works for the majority of areas in the mine but fails to capture observed mineralisation pinch-outs in operational areas and at extrapolated boundaries of the deposit. These pinch-outs have the potential to negatively impact grade forecasts if not resolved manually. Using built-in software tools only, the alternative for a more accurate model is to generate each individual layer and adding tens of thousands of manual interpretation points to honour pinch-outs (based on the amount of existing drilling in the mine and number of layers). This approach would require an estimated minimum of two to four years of a full-time employee (FTE) to be exhaustively completed. This study presents an automated approach to generate pinch-out points using a set of Python scripts that only take a few minutes to run. The newly generated points are then combined into the commercial software workflow as interpretation points, honouring observed pinch-outs. The remarkable time difference between approaches removes chance of manual errors and allows mine geologists to spend valuable time in validation and testing of scenarios, ensuring they are more representative of the deposit’s geology.

May 24, 2023

By A D. Campbell

The Homer Tunnel is located in a remote area of the South Island of New Zealand and carries large numbers of tourists to Milford Sound through an avalanche prone area. The tunnel is 1280 m long with a steep ten per cent unidirectional grade descending to the west. Construction of the tunnel began in the 1930s and was completed to a nominal 6 m width in 1954. In 1996, two passing bays were stripped-out to accommodate bi-directional flow of tourist coaches. During all phases of construction and widening there have been episodes of strain bursting.The condition of the tunnel and standard of internal services is below current international practice, principally in terms of; in-tunnel air quality, fire life safety, ground support, and road safety. A number of near-miss events have occurred involving coach fires on the approaches and inside the tunnel. The national road authority, NZTA, is considering a substantial investment to improve amenity and safety of the tunnel.This paper describes the rationale for the proposed upgrade works and the investigations undertaken to enable that design. A holistic approach to road tunnel safety has been adopted that balances the key interrelated safety drivers, namely; tunnel lining, traffic operations, ventilation, power supply and egress while ensuring continuity of safe access to Milford Sound.

Mar 8, 2011

The Mobile Miner MM130 was delivered to Broken Hill in February 1992. During March the machine was extensively trialled on the surface to test manoeuvrability, climbing ability and muck handling prior to being trammed underground in April. The first cutting test on 30 April 1992 provided promising results. The machine has undergone continual development since it arrived in Broken Hill with aims of ensuring reliability and achieving performance goals. The paper gives a detailed account of recent performance comparing this with the predicted Performance.

Jan 1, 1993

Between, 1980 and 1984, the demand for non- ferrous metals in the free world grew annually by 1.5 per cent for copper, 0.4 per cent for lead, 1.4 per cent for zinc, and 2.5 per cent for nickel. The growth rate decreased substantially compared to the rate experienced before 1980, and was far lower than the GNP growth during the corresponding period. The main reasons for this are considered to be 1. resource-saving efforts by industrialized countries resulting from the first and the second oil crises, 2. saturated demand for durable consumer goods, and 3. substitution of non-ferrous metals by new materials such as optical fibers.

Jan 1, 1986

Intensive exploration for iron ore in the banded iron-formations (BIF) of the Pilbara region of Western Australia began in the early sixties and almost immediately established the Hamersley area as a major iron province. The early genetic models for the BIF-hosted ores were based mainly on macroscopic examinations of ores from the "hardcap" zone, and generally accepted a direct relationship with weathering effects on a Mesozoic to Tertiary land surface. Brandt (1964) was the first to suggest a difference in age between the high-grade hematite ores and the more common hematite-goethite types. He initially accepted a supergene origin for both, but later opted for a hydrothermal origin for the hematite ores. Apart from MacLeod (1966), the published views of the next decade reflect a largely parochial interpretation of individual ore bodies, centred mainly on supergene models but with some support for hydrothermal concepts. Except for Ayres (1971), none of the models were backed by detailed mineragraphic data. In 1976, an AMIRA-sponsored CSIRO group began a Province-wide investigation of the wide variety of ore types and BIF, with emphasis on geochemical and textural studies. The resulting conceptual model for a world-wide unified supergene and supergene-metamorphic hypothesis is generally accepted in the Hamersleys.

Jan 1, 1986