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By Stewart A. M, Price D

This paper presents recent findings concerning longwall caving mechanisms relating to Australian mining conditions and their effect upon longwall support requirements and behaviour. The findings are based on a program of intensive hydraulic support monitoring in a variety of Australian mining conditions coupled with geotechnical observations.

Jan 1, 1992

By Wright R, Stock E. C

The Windarra nickel deposits known to date comprise two sulphide orebodies located at Mount Windarra and South Windarra. These orebodies, which are 15 km apart, lie within an ultramafic complex at or near its footwall contact with a banded iron formation. The Windarra deposits are 270 km north-northeast of Kalgoorlie in West- ern Australia which was the centre of a major nickel exploration programme fol- lowing the discovery of nickel deposits at Kambalda in 1966. Surface indications of the Mount Windarra orebody were discovered in 1969 by Mr. Ken Shirley while prospect- ing the Laverton area for Poseidon Ltd. (then NL). The mineralisation was loc- ated by systematic prospecting for goss- anous material associated with aero-mag- netic anomalies and ultramafic rocks. The South Windarra deposit was dis- covered in 1971 by the Union-Hanna- Homestake Joint Venture, by exploring along the strike extension of the mount Windarra ultramafic-banded iron format- ion contact. A detailed ground magnet 1. Acting Operations Superintendent, Windarra Nickel Project, Windarra, W.A. 2. Senior Geologist, Windarra Nickel Project, Windarra, W.A. 3. Mine Geologist, Windarra Nickel Project, Windarra, W.A.

Jan 1, 1973

The Ok Tedi Project has been planned as a selective mining operation since the Feasibility Study. The nature of the orebody, and the need to 'stage' the infrastructure buildup meant that initially the mill would process gol ore using a leach-CIP process, followed by parallel leaching of gold ore and flotation of copper ore, and finally all flotation of copper ore. Cutoff grades were applied to gold and copper ore of 1.0-1.3 g/t Au and 0.4-0.3% Tot. Cu. Since startup, unpredicted occurrences of sulphide copper and, to a Lesser extent, carbonaceous material, has necessitated significant additional short term drilling (other than at grade boundaries), and shift grade control in the pit to control contaminant levels. Remodelling of the orebody based on the most up to date variography and geological interpretation has had a significant impact on the reserves, and thus the whole project development strategy; necessitating the earlier processing of copper ores, and preflotation of the gold ore.This paper discusses some of these points in detail, and in particular highlights how unforseen geological occurrences coupled with processing restrictions can have significant impacts on ore reserves and the mine development schedule.

Jan 1, 1986

By Bailey S, Avraamides J

Laboratory-scale experiments were conducted in a mechanically stirred aeration vessel to determine the rusting abilities of aerated water in the presence of various catalysts compared to the industrially used ammonium chloride. The catalysts used were tartaric acid and citric acid, firstly by themselves, and then in later experiments mixed with ammonium chloride. From these experiments it was found that leaching of iron from reduced ilmenite in the presence of either tartaric acid or its sodium salt was much slower than in the presence of ammonium chloride. Citric acid or its sodium salt also give a slower rate of leaching than the ammonium chloride system, but citric acid and its sodium salt mixed in equal proportions produced a rate of leaching approximately twice as fast as the standard ammonium chloride system. When tartaric acid was mixed with ammonium chloride the leaching rate was found to be equivalent to the leaching rate of the same amount of ammonium chloride alone, thus indicating that tartaric acid made no contribution to the leaching in this svstem_

Jan 1, 1996

By Cripps-Clark CJ

Sulphur partition between metal and slag has been examined on a cast-by-cast basis for BTIP furnaces. Partition values. were calculated from thermodynamic equilibrium data together with oxygen activities computed from the manganese partition. The S-C interaction coefficient, esc , was treated as an adjust- able parameter and the agreement between calculated and measured S partition values optimized. In the case of furnaces operating with low viscosity slags this procedure led to estimates of esc in close agreement with previously measured values. The same analysis applied to daily average data for several Kawasaki Steel furnaces led to the same esti- mates of e c s , indicating a similar approach to equilibrium. Silicon partition between metal and slag has been examined on a time average basis and found to be far removed from thermodynamic equilibrium for most Australian furnaces. A study of Japanese furnaces of comparable size reveals a temperature dependence of Si parti- tion which appears to be close to equilibrium. Australian furnaces approach this behaviour only when operating with low viscosity slags. A preliminary examination of the effects of burdening with TiO 2 on the silicon partition is also reported.

Jan 1, 1980

By E Forbes, G V. Franks

"This study investigates the dual function of a temperature responsive anionic co-polymer of poly (N-isopropyl acrylamide) (PNIPAM) as a selective flocculant/flotation collector. PNIPAM is used for separating hematite from 50:50 mixtures of hematite and quartz, at a variety of particle sizes. The performance of PNIPAM in this system is compared to that of conventional flotation collectors: sodium oleate and sodium dodecyl sulfate. The results of the study demonstrate that anionic PNIPAM used at 50¦C (above the lower critical solution temperature (LCST)) is the most effective flotation collector for hematite particles in the size range between 10 and 20 ¦m. This is attributed to the increased probability of both particle/bubble collision and particle/bubble attachment through the formation of hydrophobic hematite aggregates. Anionic PNIPAM used at 50¦C also produced the highest hematite recoveries for very fine hematite particles (circa 1 ¦m). However this recovery was completely unselective. This lack of selectivity is partially attributed to the activation of quartz particles by PNIPAM, but is thought to mainly occur as a result of entrapment of quartz particles within the matrix of hematite aggregates.CITATION:Forbes, E and Franks, G V, 2013. Selective separation of hematite from quartz by flotation using a temperature responsive polymer, in Proceedings Iron Ore 2013, pp 381-390 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 12, 2013

By Renwick MT

Two innovative ground reinforcement products have been developed for use in the mining industry. One of these products is a high strength polyethylene (HOPE) bar for use as a rib bolt in underground coal mining and as a corrosion proof tendon in open pit mines. The other product is a cable bolt (Ultrastrand) which demonstrates enhanced load transfer and is available in continuous lengths. Ultrastrand's exceptional in- situ performance and versatility makes it ideal for mechanised installation in both underground and surface mining operations. Details of these products are presented and results from labortaory and field trials are discussed.

Jan 1, 1992

By Kyle J. H, Browner R. E

The selective adsorption of gold cyanide by the weak base ion exchange resins, PAZ-4* and Duolite A-7*, the neutral polymeric adsorbent, Amberlite XAD7*, and the strong base resins, PAZ-8 and IRA-400+ have been studied in both low and high salinity waters, and performance compared with activated carbon. The selectivity of the neutral polymeric adsorbent and activated carbon for gold decreased in highly saline water, while the selectivity of weak and strong base resins for gold increased in highly saline water. This supports the contention that the adsorption mechanism for neutral polymeric adsorbents and activated carbon is the same. Copyright

Jan 1, 1992

By Perring CS, Hill RE, Barnes SJ, Vallance SA

The Maggie Hays nickel sulphide deposit is located at latitude 32¦ 15 'S, longitude 120¦ 30' E on the Lake Johnston (SI 51-1) 1:250 000 map sheet. The deposit occurs in the Lake Johnston greenstone belt, in the Southern Cross Province of the Archaean Yilgarn Block, 500 kilometres east of Perth, Western Australia (Figure 1). The remoteness of the Lake Johnston greenstone belt and its poor access, restricted previous exploration activities and the full appreciation of the geology and its Ni-sulphide potential. It was not until 1991, when Forrestania Gold NL commenced exploration activities, that the geology of the ultramafic units and their potential to host significant concentrations of Ni sulphides were clearly established. This paper, which describes the geology and the characteristics of the Maggie Hays deposit, is based on the results of exploration by Forrestania Gold NL and a collaborative research agreement between CSIRO Division of Exploration and Mining and Forrestania Gold as reported by Perring, Barnes and Hill (1994), Perring and Hill (1995), Perring (1995 a and b) and Barnes, Perring and Reilly (1995). A comprehensive description of the geology, petrology and geochemistry of the deposit is being prepared for publication by CSIRO (Pemng, Hill and Barnes, in press).

Jan 1, 1996

The results of about 30 years of exploration and mining activities and research studies in the Kambalda mining district, Western Australia, have led to general agreement that the komatiite-associated Ni sulphide ores formed as a result of igneous processes (Ross, 1974; Ross and Hopkins, 1975; Gresham and Loftus-Hills, 1981; Cowden, 1988; Lesher, 1989 and many others). Despite this agreement, the controls on sulphide supersaturation and concentration of the resulting sulphide in a limited zone, remain uncertain and controversial. A major uncertainty is the source of sulphur in the ore deposits. Two principal sulphur sources have been proposed: 1. komatiite lava/magma (Hudson, 1972; Naldrett, 1973; Lesher et al, 1981; Cowden, 1988; Foster et at, 1995), and 2. sedimentary material (Groves, Barrett and McQueen, 1979; Lesher, Arndt and Groves, 1984; Lesher, 1989; Lesher and Campbell, 1993). Resolution of the uncertainty regarding the sulphur source is required for a complete understanding of the controls on ore formation, which in turn would significantly impact exploration strategies in the Kambalda mining district and elsewhere. This paper reviews the constraints on sulphur sources for the komatiite-associated Ni sulphide ores in the Kambalda mining district. The focus is on the general characteristics of the ores and surrounding rocks: individual ore deposits are not described, though specific examples are noted where appropriate. The stratigraphic and volcanic settings and geochemical (major and trace element and isotopic compositions) characteristics of the ore deposits and surrounding rocks are considered within the context of the competing sulphur source models, and future directions of research in the district are noted.

Jan 1, 1996

Recent mineral exploration successes in the Proterozoic rocks of the Mount Isa Inlier are unprecedented in the regionÆs history. This new era of discovery, particularly for æblindÆ deposits, owes its origin to perseverance and advances in geoscience and exploration techniques, notably geophysics. Prospective host rocks outcrop over more than 50 000 km2 of the Mount Isa Inlier and extend a further 100 000 km2 below cover. They contain major deposits of copper, lead, zinc, silver and phosphate (Georgina Basin) and significant deposits of gold, uranium and cobalt. The discovery in 1923 of silver, lead and zinc at Mount Isa established the regionÆs world-class mineral potential. Since 1990, major orebodies have been discovered at Cannington (silver-lead-zinc), Century (zinclead-silver), Ernest Henry and Osborne (copper-gold) and extensions to known deposits at Dugald River and George Fisher (zinc-lead-silver), and Esperanza (copper). This success is of global significance and reflects a prospectivity upgrade since widespread copper mineralisation was discovered and mined in the Cloncurry district a century ago.

Jan 1, 1998

By Gostylla W

The economic feasibility of controlled district cross-cut recirculation is examined in this paper with particular reference to the most important mine ventilation network parameters. An algorithm is developed to express the annual cost of recirculation which is then compared to the annual cost of conventional ventilation using the University of Queensland Experimental Mine as a case study. The concepts of resistance ratio and volumetric efficiency ratio are introduced and used to analyse the economic feasibility of controlled recirculation within a mine ventilation network.

Jan 1, 1988

By Shoobridge PH, Firkin GR

The Imperial Smelting Process blast furnace (ISF) of the Sulphide Corporation Pty Limited zinc/lead smelter at Cockle Creek, New South wales, has in recent years greatly increased its consumption of low grade feed materials, and as a consequence has experienced periods of unstable furnace operation. Routine examination of production sinter, including softening characteristics and micro- examination, showed that the problems had been caused by an increasing silica content in sinter. The silica entered a low melting point glass phase containing calcium and lead oxides. The relative volume of this phase increased until it formed a continuous matrix in the sinter structure and this made the sinter more likely to soften at lower temperatures. Premature softening caused loss of operating stability in both the shaft and hearth of the ISr. The required sinter structure for ISF smelting was found to consist of a network of intermeshing, refractory crystals which provided skeletal strength for sinter lumps even after the glass phases had begun to soften and melt. With an understanding of the importance of microstructure and softening temperature of zinc/lead sinter and the progressive identification of those factors in sinter production which affect the microstructure, a significant improvement in stability of operations has been possible.

Jan 1, 1980

In 1972, metallurgical testwork on Renison ore indicated a significant proportion of low specific gravity, tin-barren material ideally suited to heavy medium separation (HMS). Further technical and financial studies provided adequate economic justification and in December 1974 the Renison HMS plant was cannissioned. Initial operations were interrupted by the imposition of tin production quotas for three months in 1976; they were also beset with difficulties particularly with regard to mechanical wear. During the first two operating years much develognent work was carried out including installation of a pyrrhotite flotation bank in the medium recovery circuit, investigations into various wear-resistant materials and the use of atanised rather than milled ferro-silicon. By 1977/78 financial year satisfactory performance had been achieved and since then the average floats rejection has been 18.8% of the total ore treated with an associated tin loss of 2.96%. Developnent has nevertheless continued during the last three years, principal modifications being the installation of larger aperture desliming screens and improvements to the overdense cyclone circuit.

Jan 1, 1978

By Coombes J, Richards W. L

The objective of this paper is to illustrate, in a practical way, how both geologists and mining engineers can use conditional simulation to add value to their decisions. Inherent assumptions, requirements and essential components of condition

Jan 1, 1998

By H Chalcraft, T D. Mullen

Conditions encountered at a recently completed brownfields mining project provided valuable insight into, and development of, techniques for working in and around known underground mining voids in an open cut environment. The careful application of underground blasting principles to a pit environment and successful excavation whilst maintaining appropriate stand-off distances were two primary areas of innovation enabling the success of the project.Mary Mac Hill is a gold deposit situated less than 2 km south-west of the town of Laverton, Western Australia. It is owned and mined by Crescent Gold Limited. Previous underground mining by various other mining companies has left an extensive network of underground horizontal development, subvertical stopes and shafts, some of which daylighted at surface. This was identified as potentially posing substantial risks, which would prevent the application of conventional mining methods. Two major stopes were located under a hard banded iron ridge topped by a peak of cap, connected variously by narrow drives and vertical development. Due to the proximity of the first of these stopes to the surface, its dimensions and governed by procedures and advice provided by externally engaged engineers, Crescent Gold could not access the area of the ridge immediately overlying the stope using conventional open cut mining methods. This was the first of many hurdles surmounted in mining this deposit.The following report outlines how the challenges this geometrically complex deposit presented. Solving these problems enabled the team to mine the contained gold ore to a completed design, without subjecting personnel or mining equipment to harm due to a void breach incident. This paper outlines the numerous complications and difficulties Mary Mac Hill posed and explains the strategies developed to overcome them. The report also presents technical mass blasting details explaining two of the critical crown pillar blasts.CITATION:Mullen, T D and Chalcraft, H, 2012. Mary Mac Hill - The challenges and strategies of successful open cut mining: A complex underground gold deposit riddled with a network of complicated voids, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 89-96 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

During late 1953 and early 1954, tests were carried out in Sydney metropolitan brickpits in order to determine if some improvement might not be effected in the personal shock, fly rock and possible ground displacement accompanying daily blasting occurrences in the numerous quarrying activities of the metropolitan area. As a result of this preliminary work (Reid, 1954), the Department of Mines decided to further investigate the problem with a view to placing this type of blasting on a sound economical and safe basis for both operator and nearby residents alike. To assist in the work, a Cambridge Universal vibrograph was acquired.Human safety was the first consideration followed by property damage to homes and factories in the extractive areas. Although most of the actual field work has been confined to the Sydney metropolitan area and in particular to the large clay-shale quarries, many cities and country towns have blasting problems associated with the extractive industries, engineering projects both above and below ground level, and in building excavations to which the results may apply.The following figures illustrate how much activity of this type is located around cities and towns:Sydney Metropolitan Area:

Jan 1, 1958

By Cripps-Clark CJ, Deague TK

In order to study conditions under which SiO(g) may be formed in a blast furnace, equilibrium phase diagrams were constructed for the combustion of high and low ash cokes with oxygen-enriched blast and oil injection under conditions of high and low raceway pressures. Free energy minimisation techniques were used to calculate the composition of gaseous and condensed phases. Where coke ash is assumed, for simplicity, to comprise Si02 only, the coke can be comple- tely gasified, mainly to SiO and CO, under restricted conditions of coke to blast ratio and at temperatures greater than 1600 - 1650¦C, depending on system pressure. The formation of SiO(g) is partially suppressed by the introduction of alumina into the ash, because of the formation of solid and liquid alumino- silicate compounds. The minimum temperature for complete silicon gasification is raised to about 1700¦C. The results of the equilibrium calcula- tions are related-to actual raceway conditions. It is proposed that virtually all silicon in the coke ash is gasified such that, on condensation, it affects hot metal chemistry and slag properties and secondly, that the effects will be greater with higher ash cokes.

Jan 1, 1980

By D Feng, G C. Lukey, J S. J, R R. Dagastine

An ongoing challenge in the coal industry is pyrite removal using the flotation method for fine particles. The use of a æseparation in frothÆ (SIF) technique to recover coarse particles of up to a few millimetres in size has presented a potential solution. However the commercial success of SIF is still limited due to the poor understanding of the separation mechanism. The particle floatability in SIF is determined by the constructive or destructive stresses resulting from the forces exerted by the particle on the bubble films. Hence, the surfactant properties and the mineral characteristics (eg hydrophobicity, shape, etc) are the key factors that control the interaction between the particle and froth. In the present work, the interaction forces between different particles (ie crushed glass, pyrite and coal) and a single air bubble are measured in a non-ionic surfactant solution (pentaethylene glycol mono n-dodecyl ether, C12E5) using an atomic force microscope (AFM). Experimental results show that the interaction is primarily dependent on the contact angle (ie the degree of hydrophobicity of the minerals). For crushed glass, the transition from repulsion to attraction was observed as the contact angle increased. As the concentration of C12E5 increased, the adhesion force was suppressed due to wrapping effect. For coal and pyrite with much higher hydrophobicity, long-range attraction was observed. The effect of shape factor was only visible at high surfactant coverage where sign of destabilisation became noticeable on the retracting force curve. These results provide a fundamental understanding of the direct interaction forces of a complex real system between an irregular particle of either crushed glass, pyrite or coal and a single air bubble. Theories developed for interpretation and modelling are thus far based upon the study of ideal systems of glass or polystyrene spheres and an air bubble and were incapable of explaining the interactions in complex real systems. The presented measurements were a first approach to the problem of real mineral-bubble interaction in flotation systems. Thus, the results can only best be interpreted semi-quantitatively.

Jan 1, 2005

Alluvial gold exploration is aimed at recognizing areas of anomalous gold content as evidenced by the nature of the drainage system, its age, geomorphic history and other features of the geological environment including the provenances. Subsequent studies to quantify the findings are governed by the need for accurate data based upon precise measurements. Computerization allows the use of more complicated mathematical procedures than are feasible manually, thus promoting the development of more advanced technological aids. Data banks provide the means of storing vast quantities of information for instant recall.Sample representivity is a major problem and a clear understanding of both sampling and analytical requirements is essential for dealing with problems arising from variations in sample size and particle size distribution. Field samples must always be large enough to ensure adequate representivity or the sampling has failed in its purpose.

Jan 1, 1984