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By L Clarke, R N. Campbell, F Bourke, J Anderson

Lithological units have been classified geotechnically with mechanical tests and discontinuity measurements from the GRD Macraes Limited, Macraes Gold Project and Rotowaro coal mine open pits, New Zealand. Using these measurements slope stability probability classifications (SSPC) have been quantified based on an adaption of Hack's (1998) SSPC system which places less influence on rock quality designation and unconfined compressive strength than previous slope/rock mass rating systems. The Hack weathering susceptibility rating has been modified by using the chemical index of alteration values from XRF major element analysis. Slaking and weathering is an important parameter in slope stability in the Waikato Coal Measures and Otago schist lithologies and hence a non-subjective method of assessing slaking/weathering in relation to the chemical index of alteration has been introduced. Other major components of this adapted SSPC system are the inclusion of rock moisture content and rock strength anisotropy effects on slope stability. This paper explains the systematic approach of using the adapted SSPC system to classify slope stability probability. The main modifications of Hack's SSPC system are the introduction of rock intact strength derived from Mohr-Coulomb failure criteria which has been adapted for varying moisture content, weathering state and confining pressure. It is suggested that the subjectivity in assessing intact rock strength within broad bands in the initial SSPC system is a major weakness of the initial system. Initial comparison of rock mass friction angles, cohesion and strengths derived from the adapted SSPC are compared with results derived from modified Hoek-Brown criteria, MRMR and SMR classification systems. The advantage of the modified SSPC system is that slope stability probability, maximum batter and overall slope height and overall slope angle for open pit walls can be predicted in addition to orientation dependent and orientation independent stability. Examples are provided, using the modified SSPC system to predict initial optimum pit slope designs in proposed greenfield mine sites.

Jan 1, 2000

By He BQ

Static attachment of bubbles to solids is contrasted with dynamic attachment in flotation cells. The times of contact during particle-bubble collisions in dynamic attachment are compared with the induction time determinations and the kinetics of thinning of the liquid films separating solids and bubbles. The thinning is examined mainly in terms of electrostatic and dispersion (van der Waals) contributions to the disjoining pressure existing in the films. The local heterogeneity (on a molecular scale) of charge distribution invariably present at all interfaces (even at conditions of zero zeta potential) calls for some means to minimize possible electrostatic repulsions which arise when the electrical double layer at the air-bubble interface begins to overlap that present at the solid surface, on encounter between particles and bubbles. It is postulated that dipoles of frother molecules, owing to their ability to "flip over" (polarise), replace localized electrostatic repulsion by attraction within fractions of a milli- second, as long as the structure of the frother molecules is sufficiently "bulky" to maintain diffuse films (of mixed collector-frother) at the air/liquid interface of bubbles. The relaxation times of dipoles (signifying their "flipping over" ability) have to be shorter than the collision times between particles and bubbles for particle-bubble attachment to be facilitated under dynamic Conditions.

Jan 1, 1984

By Guerney P. J

A suspension of finely powdered ferrosilicon in water is the dense medium used in the gravity upgrading of iron ore, diamonds and other minerals. Ferrosilicon can he lost in the plant through corrosion. The greatest corrosion losses occur when

Jan 1, 1997

By Klinefelter G

The United States Steel Mining Co., Inc. recently experienced a major mine fire at the Cumberland Mine. This mine is located in Greene County, Pennsylvania, U.S.A. and is mining a high volatile bituminous coal seam (Pittsburgh Seam). The mine fire was success- fully controlled and extinguished without loss of life or serious injury to any miner or mine rescue personnel and finally reopened within 40 days of its inception.

Jan 1, 1988

By P Ritchie, E H. Briese, N A. Currey

Kidston Gold Mines, located in semi-arid North Queensland, Australia is currently in its closure phase. Highly innovative and comprehensive rehabilitation strategies were employed at the site, including the direct revegetation of the surface of the tailings storage; the construction of a tailings sediment entrapment pond; the construction of a spillway to drain large rainfall events from the surface of the tailings; the construction of store/release covers over the tops of the waste rock dumps; the sheeting with oxide waste rock of the waste rock dump slopes; the partial back-filling of the initial Wises Hill Pit with waste rock and thickened tailings produced from the subsequent Eldridge Pit; the partial flooding of Eldridge Pit following the end of mining; and the construction of wetland systems to treat contaminated tailings and waste rock dump seepage. These closure strategies involved the careful consideration of water management. Specific water management issues included understanding the water balance of the tailings dam; the operation of the tailings dam sediment entrapment pond and spillway; understanding the water balance of the store/release waste rock dump covers; the importance and sustainability of vegetation on the tailings, store/release waste rock dump covers, and on the sheeted waste rock dump slopes; the level and quality of water in the partially flooded Eldridge Pit; and the treatment of contaminated seepage in the constructed wetlands. The seasonal and highly variable rainfall experienced in this semi-arid climate posed a number of challenges for the management of water on the site post-closure. The paper details these challenges and highlights how they were resolved over the period leading up to and following the end of mining.

Jan 1, 2003

It is my role at this juncture to report to you on behalf of the Council of Mining and Metallurgical Institutions itself. In essence, the Council is an orbital body - a little like Halley's Comet - it returns to earth, in spectacular style, once in every four years. We must acknowledge, however, that the spectacle is provided by the constituent member body organising the particular event and, on this occasion, it is The Australasian Institute of Mining and Metallurgy. On behalf of the Council and its other constituent bodies may I thank the Australasian Institute most sincerely. Our thanks go to Sir James Foots, the President of the 13th Congress, and to all the members of the organising committee and to the five sub- committees. Over 40 people are involved as full members and I am certain there will have been many more involved in very meaningful ways. None of this great- team would ask me to mention them individually, I'm sure, but to fail to acknowledge the role of John Funnell, the Honorary Secretary, would be an unforgivable omission. We must also thank the kindred institutions in Japan, Korea, Thailand, Malaysia, and Indonesia who all helped with the tours themselves or with the initial preparations. Qantas, Jetabout Australia, and Jetabout Singapore have all also made very important contributions and, in our different ways, we each owe our thanks to them. At the two most recent meetings of the Congress - in Hong Kong and Johannesburg - Professor Marston Fleming made this report on behalf of the Council and was supported on both occasions by Robert MacWilliam as vice- chairman. Marston died in 1983 and Robert died in 1984; both men contributed a great deal to CMMI and we will miss their counsel for a long time. As you know, Sir Alistair Frame succeeded Marston Fleming as chairman in 1984 and I succeeded Robert MacWilliam as Vice-chairman.

Jan 1, 1986

By A Prill

Safety First and zero accidents are the targets most mines in Australia are aiming for, but manual processes and procedures limit the capabilities and response time in emergency situations. Even with a high safety focus, accidents and incidents still happen, too often with tragic outcomes. Dangerous areas, narrow roads and winding curves are all daily obstacles that threaten workforce safety. Every unforeseen event, such as traffic collisions and other accidents, puts lives in danger and weakens production. Safety must be guaranteed.

May 5, 2022

International tenders for contract mining opportunities require the Contractor to make an assessment of risk for an operation with a life span of up to twenty-five years usually based on data made available by the Client. This paper seeks to address how the Contractor assesses the data and quantifies the risks associated with the project. The areas of risk are common to most projects, but in the--Lontractor's case, risk assessment is carried out on the Client's data base and within a compressed time frame of usually less than six months. Incorporation of that risk assessment into the contract documentation is also discussed. Practical examples are given in a number of areas.

Jan 1, 1986

By O N. Antzutkin, A V. Ivanov, W Forsl

Polycrystalline and surface complexes (at synthetic sphalerite, ZnS, and galena, PbS) of zinc(II) and lead(II) ions with eight different O,OÆ-dialkyldithiophosphate (Dtph) substances have been prepared and comparatively studied by means of 31P CP/MAS NMR spectroscopy. The 31P resonances have been assigned to dithiophosphate groups with terminal S,SÆ-chelating or bridging coordinations in the mono-, bi-, tetra- and polynuclear complexes respectively. The bridging coordination of two neighbouring zinc(II) ions by O,OÆ-dialkyldithio-phosphate ligands was established at the surface of synthetic sphalerite.The adsorption mechanism of dialkyldithiophosphate on synthetic galena includes formation of a surface complex as well as surface precipitation. Principally different coordination modes of the reagent were discovered at the surfaces of galena and sphalerite (ie terminal S,SÆ-chelating coordination to the lead atom).Derivatives of monothiophosphoric and phosphoric acids were displayed as hydrolysis products of dialkyldithiophosphates at synthetic PbS.

Jan 1, 2005

The Grootegeluk coal beneficiation plant is situated near Ellisras in the Waterberg coal= field in the Transvaal, RSA. At this plant 15 million tons of coal bearing material per annum are beneficiated by means of two-stage heavy medium bath and cyclone plants. Because of the very low yield of 12 % coking coal product, run= ping costs are of the - utmost importance. For this reason extensive tests were carried out to establish the most effective crushing and bene= ficiation methods and suitable aquipment. At the second heavy medium separation stage, the near-gravity material (+ 0,1. g/cc) amounts to 45 % and daily plant performance ana=lysis is required to ensure acceptable plant efficiency. Beneficiation processes for the -0,5 mm coal originally considered were froth flotation, shaking tables, heavy medium cyclones and water- only cyclones. When the froth flotation route was decided upon, further test work was done to enable selection of the equipment most suitable for the particular requirements.

Jan 1, 1987

By E Giles

Pike River Coal Limited (PRCL) is opening a new underground coal mine in the Paparoa Ranges north-east of Greymouth. To access the coal reserves, PRCL have had to build a 13 km access road through regrowth and virgin forest, and appointed McConnell Dowell Constructors Limited, with URS New Zealand Limited as their consulting engineers, to construct the final access link: a 2.3 km long, 5.5 m wide and 4.5 m high incline tunnel. This paper discusses the logistical issues of construction in an isolated pristine forest in mountain land and how they were addressed. It provides an overview of the 90 per cent complete tunnel and how challenging rock conditions have been mastered. It outlines briefly the remaining work which is construction of pit bottom workings where the mine infrastructure will be housed and construction of a 110 m deep, 4.0 m diameter, vertical ventilation shaft.

Jan 1, 2008

By H Bleuler

A new portal and access drift was constructed by Concrete Constructions for BHPÆs Elouera Colliery, south of Wollongong.The portal area at the base of the Illawarra Escarpment is in soft colluvium material, underlain by highly to moderately weathered sandstone. The area has a well documented history of slope movement or slope creep and one of the main criteria for the design was to minimise disturbance to the unstable slope by limiting the excavation for the portal establishment. This was achieved by incorporating a sloped headwall and gabion wingwalls to accommodate the anticipated creep and groundwater seepage.Main features of the design process also included the provision of both primary and secondary support in a single shell application and the use of canopy tubes to provide support ahead of the tunnel face.The active involvement of the designer during the construction phase and the flexibility of the design concept allowed changes to the support methodology to be carried out as excavation proceeded.This paper describes the design process undertaken for portal establishment and access drift to cater for the variability of the exposed ground conditions along the drift alignment.

Jan 1, 1999

Universal Resources Ltd has acquired a large portfolio of high quality exploration projects in two of Australia's most prospective regions for base and precious metal exploration: the Mt Isa Inlier (the Mt Isa-Cloncurry area) of North West Queensland, and the southern Lachlan Fold Belt in New South Wales. Drilling techniques commonly employed by the company for mineral exploration include diamond core drilling, air core drilling, reverse circulation (RC) drilling, and rotary air blast (RAB) drilling. Using examples from these two regions, each drilling technique is briefly described and compared, with particular reference to the specific advantages and disadvantages of each method for: sampling size, sample representivity, recovery, integrity and potential contamination. The applicability and implications of the different drilling techniques described for subsequent mineralogical and metallurgical evaluation work are discussed.

Mar 1, 2010

Diamond bearing deposits are extremely low grade and require large bulk samples to be tested to determine the grade and quality of the stones. The semi portable plants, for treatment of these bulk samples, have followed the development of commercial processes for diamond concentration. These processes included jigs and diamond pans, which have been largely supplanted by heavy media processes for primary concentration, due to the higher efficiencies in all size ranges. A number'of flowsheets including these processes are presented. The final recovery of diamonds from the bulk sample concentrates can be accomplished by rejigging, adherance to grease or by X-ray sorting. Flowsheets incorporating all the processes are presented. Two plants are described; one incorporating jigging, rejigging and hand sorting; the other using heavy media separation, and wet X-ray sorting.

Jan 1, 1984

The present stage of economic development of the Broken Hill lode, attained after 40 years of active exploitation, leaves little opportunity for the study of the zone of secondary sulphides.Little remains of the oxidised zone, and the observations of the secondary sulphides of copper and silver can rarely be made on specimens collected in situ. A few specimens containing secondary...

Jan 1, 1927

We all live in professional silos û comfort zones, where we talk to like-minded people with the same training, experience and view of the world. We note in passing the existence of other disciplines, but they are tolerated rather than embraced. To the geologist, the metallurgist is a mad scientist conjuring gold out of some foul solution about which the less said the better. To the metallurgist, the geologist is a bearded, self-appointed sage who guesses what is under our feet by sniffing the air, and drives a Land Rover badly. As to the view of mining engineers held by both geologists and metallurgists, this is best left to the imagination. And of course we are all confused by the term æmetallurgistÆ. I am called a metallurgist though my skills are in mineral processing not metal processing, but I canÆt be called a mineralogist because that definition is already taken. *Please note that this is available as an extended abstract only*

Jan 1, 2005

Excavation through fill material in underground metalliferous mines is usually avoided where possible, unlike in Civil Engineering application where excavation through soft ground is normally a matter of course. In the mining situation, where excavation is normally for access only, then excavation designs are engineered for mining in hard rock, except where previous lack of forward planning has made such excavation inevitable or a mining strategy sequence necessitates some mining through fill in order to achieve optimum recovery of ore. Historically, this has been the case, because of the lack of knowledge of the support characteristics of the fill material placed underground and the lack of knowledge of the composition of the fill material as placed. The expertise and experience available from mechanised excavation techniques in Civil Engineering application (shield jacking, forepoling, spiling, and soft tunnel boring, to name a few) are available for application to the underground mining situation if the need ever arises. This paper describes the situations in underground mining development where mining through fill material is required, the different types of fill material encountered and the types of support available

Jan 1, 1981

By O J. Restrepo Baena, S Nowosad, R Webber-Youngman, N Mojtabai, P Foster, A Binder, S Hazuria, erson, S Raval, L Liu

As the mining industry faces times of change, new challenges arise to ensure raw material supply for the younger and future generations. Different scenarios are currently shaping the way we mine and teach mining engineering. Led by an increasing demand for raw materials, net zero requirements for improving long-term operation performance, technological advancements such as automation and digitalisation, safety improvements, environmental considerations and a need for social acceptance, mining is pursuing to change and adapt to these requirements at a faster pace. Such changing times raise new concerns, one of the most relevant is the lower number of students interested or enrolling in mining engineering and related fields leaving mining engineering as one of the less preferred career options between the younger generations. Nonetheless, it is essential to continue addressing and supplying the skill sets that is suited to contemporary and future of the mining industry. To this end, globally, academia is currently undergoing several initiatives such as curricula updates and adaptation, up skilling, improving teaching practices and techniques, including e-learning techniques, enhancing industry-academia and inter-university collaboration, and much more

Sep 1, 2024

By Ellson I. G

Shay Gap was created for the sincrular purpose of housing, in comfort, the workforce that would be required to mine iron ore, from leases held by Goldsworthy Mining Limited, in hill country, approximately 170 kilometres east of Port Hedland in the Pilbara region of Western Australia. To combat the and environment, the Company ultimately decided to adopt a novel planning concept for the town, which had not been attempted before in Western Australia. The special problems encountered during planning, and the reservations that were expressed during construction and early settle ment, are now part of the dim past. During the three years of occupation now achieved, there has been accumulated a story of success in the provision of an acceptable alternative to modern suburbia. Not only may this be claimed, but it can also be argued that the Shay Gap concept has been a more successful solution to a real environmental problem in our arid Pilbara region than has been seen in other similar settlements.

Jan 1, 1976

Coal geology plays an essential role in the investigation of in situ coal seam quality. Coal geology can also play an important part in laboratory studies such as coal washing and coking, and in operating plant problems.

Jan 1, 1976