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Indiscriminate surface disposal of coal waste in New South Wales has created a serious fire hazard and increased air pollution.A survey of numerous dumps, as well as particular investigations of one badly-constructed dump, showed that factors conducive to ignition and propagation of fires in waste dumps were high contents of combustible material (coal, pyrite, wood. paper. grease), size segregation leading to ready movement of air and moisture shape of the dump (e.g. protruding sections or porous junctions), high ambient air temperatures, bush fires, and even deliberate lighting.Control methods applied in the past tended to be haphazard and unsuccessful. Under Australian conditions the technique recommended for control of existing dump fires, based on experimental work, is to spray the dump with a chemical fire retardant (e.g. a 2 per cent solution of sodium tetra borate and ammonium phosphate), to cover the dump with a suitable soil, and to seal the surface with a I per cent solution of aluminium sulphate or sodium metasilicate. The recommended method of dump construction to prevent fires is to level and seal the site, to construct a firebreak around the dump area, and to build a rectangular dump with minimum size segregation and compacted surfaces.

Jan 1, 1971

By Wilson R. G

The Bulli and Wongawilli Seams, the two principal sources of coking coal for the Port KKembla steelworks of Australian Iron and Steel Pty. Ltd., vary in rank and in type over the Southern and -South Western Coalfields. The Bulli Seam, ranging widely in type, produces coke varying from weak to strong. The Wongawilli Seam, more consistent in type, produces coke of more consistent strength, but considerably less strong than that from the best Bulli Seam coal. Plans of seam variation show the regional trends in rank and type for each sear. The strongest coke is derived from coal containing between 45 and 55 per cent vitrinite, m.m.f. This is obtainable from the Bulli Sean in a zone embracing Bulli and Appin Colleries.

Jan 1, 1969

By Hannington MD

On the southern flank of Lihir Island, a group of three volcanic cones were discovered at water depths from 1000-1500 m. The volcanoes are located in a narrow zone of recent seismic activity and elevated heat flow (up to 100 mW/m2). The recovered rocks consist of fresh alkali-olivine basalts, clinopyroxene-rich basalts, and porphyritic phlogopite basalts. One of the volcanoes has a recently erupted ejecta blanket (recovery of warm ash!), containing a suite of abundant mafic to ultramafic xenoliths. These xenoliths appear to represent a unique cross-section of subduction- modified mantle material sampled by volatile-rich primary fore-arc magma during its ascent to the seafloor. The most spectacular finding was the discovery of an active hydrothermal system with associated vent fauna and mineralization at Edison Seamount, and the recovery of unusually gold-rich (up to 43 ppm Au) hydrothermal precipitates in 1050 m water depth at the top of Conical Seamount, only 25 km south of the world-class epithermal Ladolam gold deposit on Lihir. The discovery of submarine hydrothermal vents associated with highly alkaline, quartz-undersaturated fore-arc volcanics represents a significant departure from similar hydrothermal systems on the mid-ocean ridges and in back-arc basins. The high gold grades in hydrothermal precipitates at Conical Seamount may indicate the first documented example of a shallow-marine epithermal system analogous to those known on land, and has important implications for the gold potential of submarine arc environments.

Jan 1, 1995

By Case JE

Complete Bouguer and isostatic anomaly maps compiled for Costa Rica provide new insights into the crustal structure and mineralization. Terrain corrections were approximated from the station to a radial distance of 167 km by computer using a 3- minute digital elevation model of Costa Rica and surrounding areas. Isostatic corrections, based on Airy-Heiskanen compensation, were also calculated from 0 to 167 km using the 3- minute elevation model and from 167 km to 180 degrees using combined topographic and isostatic reduction maps. Costa Rica can be divided into four main terranes based on gravity data: a Pacific coastal region, a Pacific inland area, a central region, and a Caribbean coastal region. Negative gravity anomalies along the Pacific coastal margin correlate with an offshore sedimentary basin, and large positive anomalies correlate with mafic and ultramafic igneous rocks on the Santa Elena, Nicoya, and Osa Peninsulas, and at Puerto Quepos. Pacific inland anomalies are separated from the Pacific coastal region by a steep gravity gradient, and over the Coast Ranges a major gravity low overlies a thick section of low- density sedimentary rocks. In the central region, a major gravity low occurs over a thick low-density Quaternary volcanic complex in the Cordillera Central, north of San Jose. A prominent feature of the Caribbean coastal region is an interrupted gravity low over the Limon Basin that reflects a thickening of low-density sedimentary rocks. A conspicuous gravity lineament, trending northeast separates northern and southern Costa Rica. The lineament is defined by the termination of several major gravity anomalies including those over the Coast Ranges, Cordillera Central, Puerto Quepos, and Limon Basin. In addition, the lineament correlates with other geological and geophysical data including: northeast-trending faults, the southern limit of large Quaternary volcanoes, the segmentation of the middle America volcanic belt, and a seismicity gap. This lineament may be the expression of a previously unrecognized major northeast- trending fracture zone in central Costa Rica. An important economic implication of the gravity lineament is a correlation with the termination of gold and porphyry copper deposits in Costa Rica.

Jan 1, 1987

By Mallett CW, Hammond RL

Geological maps of the Pacific Rim recently published by the Circum-Pacific Council for Energy and Mineral Resources have provided a useful perspective from which to view modern plate interaction and the evolution of modern fold belts. An important lesson from any study of modern plate interaction is that of the normality of change. The chaotic is more usual than the simple. Present day convergent margins with mixed characteristics are measures of this chaos. Indeed, the character of less than one third of the present length of the Pacific Rim can be ascribed to conventional models of plate interaction. Another lesson is that of the great mobility of oceanic crust. Enormous areas of the Pacific may not be represented in future fold belts developed at convergent boundaries unless normal consumption processes are disrupted, and even then only by linear zones a few kilometres wide. The axes of divergent boundaries creating Pacific Ocean crust have been equally mobile, with new spreading sites taking over from older sites through time. Divergent boundaries, whether active or inactive, consist of oceanic crust, and may be wholly consumed at collision sites with convergent boundaries. Their only potential contributions to fold belt evolution are transforms and magmatic activity. It is this transform component that can provide us with a mechanism to explain the apparent contradiction of both compressional and extensional features occurring together in a developing fold belt. Reconstructions for the SW Pacific are used to demonstrate that the fold belts under construction during the last 4% (Jurassic- Recent) of geologic time have involved interaction between convergent, divergent, and transform boundaries. In the last 15% of earth history (Late Proterozoic-Recent), many enigmatic features of the geologic landscape in Eastern

Jan 1, 1987

By Baafi EY

Geostatistics is now widely used in the mining industry in the estimation of ore reserves and terms like kriging, variogram and estimation variance are becoming well known. Ordinary Kriging (OK) has been found by some practioners to be a superior tool compared with other ore reserve estimators. However, kriging hasn't been the ultimate solution to difficulties which may arise in ore reserve estimation. Several additional geostatistical techniques have been recently developed for more efficient ore reserve estimation in some deposits, especially gold and other precious metals. These include indicator kriging and probability kriging which are useful tools to work with in a selective mining operation.

Jan 1, 1987

By Murray C. G

A database of over 1300 earthquakes has been used to investigate the relationship between seismicity and tectonics in two areas of eastern Queensland and NE New South Wales. These areas have been monitored by several networks that were installed primarily to monitor seismicity associated with the impounding of large reservoirs. Events that occurred prior to the installation of these networks have been excluded from the analysis because they have large uncertainties in location.Seismicity in SE Queensland and NE New South Wales is concentrated in the coastal regions. Activity also extends off the coast of Queensland and beyond the continental shelf. The coastal activity is mainly within the New England Fold Belt. An area of the fold belt overlain by the Clarence-Moreton Basin is also active. There is an area of activity near St. George that correlates to the Wunger Ridge. Fraser Island and the adjacent onshore area, near Maryborough, are notably aseismic.Within the New England Fold Belt there is a NNW trending zone of concentrated activity that includes the South D'Aguilar Block and the Esk Trough as far as Gayndah. The Nambour Basin, the Gympie Province, and the southern portion of the Yarrol Block are significantly less active.Composite focal mechanisms of several groups of accurately located earthquakes in SE Queensland indicate predominantly reverse faulting. This faulting is the result of the crust being compressed horizontally in a NE-SW direction.Activity in the Burdekin Falls Dam area of central eastern Queensland is confined to the Drummond and Bowen Basins. There is also significant activity offshore from Townsville and Bowen.

Jan 1, 1990

This paper introduces a new, safer bulk emulsion loading system for underground mining operations. The features and benefits of the equipment, along with the use of Dyno Nobel Inc patented gassed emulsion technology, is summarised in the application of a stope blast with very difficult and complex ground conditions. The paper describes methods used to optimise the amount of energy required to break the ore while protecting the integrity of the surrounding backfilled pillar.

Jan 1, 2004

By M Xu and, P F. Wells, A N. Kerr, Y Shields

Triethylene tetramine (TETA) has been used in combination with sodium sulfite (sulfite) for pyrrhotite depression at Clarabelle Mill since 1998. This combination has been highly successful at reducing pyrrhotite levels in the bulk (Ni/Cu) concentrate. Although highly effective, the roles of TETA and sulfite are not well understood. Treating bulk samples of the circuit feeds through the miniplant enabled the effects of circuit configuration on the performance of the pyrrhotite rejection circuits at Clarabelle to be determined. Reasons for the different performance of the non-magnetic pyrrhotite rejection circuit in the miniplant were investigated and tested in the laboratory. The effect of different grinding environments in the laboratory was examined to better understand the depressing mechanisms of TETA/sulfite. Modification of the grinding chemistry improved the selectivity of pentlandite over pyrrhotite in the presence of TETA/sulfite at current plant dosages.

Jan 1, 2005

By Corbett GJ, Leach TM

A continued exploration programme has further defined the geology of the Tolukuma vein system, verified the resource indicated by Newmont, and identified potential for additional mineralisation. The resource at Tolukuma Hill, designated as zone C, is a mine recoverable 432,000 t at 18.1 g/t Au & 46 g/t Ag. Mining will be by a combination of open pit and underground at a rate of 100,000 t per annum. Processing will be by SAG mill, gravity circuit and CIL plant. A diatreme breccia, localised at an intersection of structures and a relationship of gold to base metal sulphides, are indicative of a strong porphyry association. Typical epithermal features such as crustiform banded quartz and quartz pseudomorphing platy calcite are also present and locally contain lesser gold mineralisation. Pre-existing dilatant structures have acted as a host to the ore fluids, resulting in the formation of the semi-continuous Tolukuma-Gulbadi veins over a 1100 in strike. A fluid flow model suggests that mineralizing fluids were sourced from a diatreme margin and migrated laterally along dilatant structures. Bonanza gold grades are interpreted to be derived through fluid quenching in the flexure between a hanging wall split, which hosts much of the Tolukuma Hill resource, and the feeder graben structure. Thus, the relationship between the pre-mineral structural geometry and fluid upflow at the margins of a diatreme breccia, controls the ore setting.

Jan 1, 1995

The total cost of horizontal development can be minimised by optimising the cost of each of the component operations (eg drilling, blasting, etc). Component costs should not be minimised. To optimise blasting results (ie the mean advance per round, muckpile characteristics and overbreak), operators need to optimise the blast design and drilling and blasting procedures. The costs of pulling extremely long (say >6 m) rounds, producing unnecessarily fine fragmentation, and minimising overbreak are excessively high. Operators should continually consider how they can shorten the cycle period by saving time at the face. To enable it to be matched to the pertinent rock properties, the blast design needs to be based on as much relevant experience as possible. To develop the most valid correlation between blasting results and blast design, the latter must be implemented carefully and accurately, but without sacrificing speed excessively. The total cost can often be reduced by using: 1. computer-controlled jumbos (to reduce the period and cost of drilling and to increase drilling accuracy); 2. larger diameter (51 mm to 64 mm) and longer (4.5 m to 6 m) blastholes; 3. at least three large diameter ( ¦89 mm) relief holes that are 0.2 m to 0.3 m longer than the blastholes; 4. explosive products that are selected on the basis of proven reliability and overall cost efficiency rather than price; and5. stemming (to increase the amount of effective work done by each kilogram of explosive and, hence, to reduce the powder factor and possibly the number of blastholes and the costs of drilling and initiation). Non-perimeter blastholes should be charged with ANFO or a bulk emulsion of established performance. Upper perimeter blastholes should be charged with a bulk explosive with a much lower effective density. But where geology varies considerably, greatest control over overbreak could possibly be achieved with the versatile pre-assembled charge shown in Figure 1. This paper presents numerous potential ways in which the total cost of development can be minimised. It concentrates on recommending blast design features and the safe, rapid, cost-effective implementation of designs.

Jan 1, 1998

By C McIntosh, M van Dam, N Whetter, R Lane, M McCulloch

Mine geology is understood through synthesising large amounts of structural, lithological, geochemical and geophysical data derived from the original topographic surface, drilling and surfaces exposed and removed during open cut and underground excavations. Computer- generated 3D geological models of any mine environment need to incorporate large amounts of information but also should be regularly updated with typically frequent influxes of new data. Geologists with the local knowledge should also be involved in the model construction, enhancement and interpretation, placing ease-of-use functionality high on modelling software requirements. Implicit-style modelling is a fast-growing area of 3D geological software development where interpolated surfaces such as lithology boundaries and bedding orientations are defined mathematically as functions rather than explicitly through coordinate meshes. The functions are constrained only by the data and not by an artificially imposed grid; therefore, implicit 3D modelling can process a lot of information quickly and routinely operate on original data (such as observed contacts and structural data) rather than on evolved iterations and interpretations. 3D mine geology models can be readily updated with new data, which can be automatically reprocessed to test ideas in near-real time. Implicit, function-based 3D modelling software has been applied to the Globe-Progress mine in West Coast, New Zealand. This structurally- hosted gold mine has some geometrical conundrums that are in part being resolved as excavation of the open pit proceeds. The relationship of the Globe-Progress ore shoots to hanging wall and footwall structure is still not fully understood, however, and 3D geological modelling is assisting with visualisation and testing of structural hypotheses. The modelling is also capable of predicting areas of bedding defect slope failure in yet-to-be excavated parts of the mine.

Jan 1, 2009

By Knight J. L, Baker G

The Wonthaggi coalfield is in South Gippsland, about 90 miles southeast of Melbourne. It is situated on the down-faulted block of the South Gippsland highlands that lies south of the Kongwak fault, between the Powlett River and the sea (Fig. 1). The coal, which is of Jurassic age, occurs in two small, and intensely faulted, limnic basins, that lie on either side of a concealed ridge of Silurian sediments. The coal was first found as thin seams outc1'opping in the cliffs at Cape Paterson, but the seams that are worked at Wonthaggi are concealed beneath a veneer of Cainozoic sands that covers the Jurassic strata, and were found by boring.The c9al seams are worked by the State Coal Mine, which was opened in 1909 to ensure a supply of coal for the Victorian railways, following a prolonged strike in the Newcastle field of New South Wales. The total production from 1910 to June, 1943, amounts to 13,918,800 long tons of coal. The coal seams are faulted to a degree unknown in most coal...

Jan 1, 1944

The extinction of zinc from steelmaking dusts has been studied with a laboratory scale reduction-vapour deposition (RVD) process in the absolute pressure and temperature ranges of 13 - 1300 Pa and 1333 - 1513 K respectively. This process consists of pre-reduction of iron oxide by carbonaceous agent, carbothermic reduction of zinc oxide under reduced pressure to produce zinc deposits and subsequent re-evaporation of the deposits to liquedify the zinc. In the RVD, the gas mixture of Zn and CO quenched from the hot zone is separated into Zn deposit and CO which is transferred to the pumping system. The Zn are a layer of fine metallic zinc powders accumulated on the cold wall and removed to the vacuum distillation chamber. The experimental works have been carried out according to the following items: carbothennic reduction of zinc oxide under vacuum, carbothermic reduction o zinc ferrite under vacuum, and 3. distillation of the Zn deposits. It has been concluded from these experimental results that the recovery of metallic zinc from the EAF dusts is successful by this process, and a new concept for a practical zinc winning process has been proposed.

Jan 1, 1993

By Schiller J. C, Both R. A

Base metal mineralisation occurs at several locations within the regionally metamorphosed Kanmantoo Group on the southeastern flank of the Mount Lofty Ranges between Kanmantoo and Strathalbyn, 50 km southeast of Adelaide. Sulphide mineralisation is of three main types (Seccombe et al, 1985):1. copper deposits, at the Kanmantoo and Bremer mines, South Hill prospect and several minor occurrences,2. lead-zinc deposits at Aclare, Wheal Ellen, Strathalbyn, St. Ives, Scott's Creek, and Glenalbyn mines,3. pyrite-pyrrhotite mineralisation of the Nairne pyrite deposit and many other pyritic schist units within the Kanmantoo Group.Syntheses of folding, metamorphism and stratigraphy of the Kanmantoo Group were given by Kleeman and Skinner (1958), Offler (1960, 1963), Offler and Fleming (1968), Marlow (1975), Mancktelow (1979) and Parker (1986). Studies of the general relationships of mineralisation to structure in the Kanmantoo area were given by Grasso and McManus (1954), Mirams (1962), Poole (1969), and Lindqvist (1969).Several conflicting views on the origin of mineralisation in the Kanmantoo Group have been proposed. Thomson (1975) considered much of the mineralisation as a late-stage product of regional metamorphism and he, like Parker (1986) and Lambert et al (1987), stressed the importance of major lineaments as an ore control. However, Lindqvist (1969) and Verwoerd and Cleghorn (1975) tentatively suggested a syn-sedimentary origin to the Kanmantoo copper deposit and Jensen and Whittle (1969) and Seccombe et al. (1985) on the basis of sulphur isotope data proposed a bacteriogenic sulphur source and a sedimentary origin for sulphides in the Nairne pyrite deposit. The latter suggested that most copper deposits represent stockwork, vein or disseminated zones within subsurface vents whereas massive mineralisation at Wheal Ellen and Aclare mines probably accumulated on the ocean floor.This paper presents new geological information on the structural and metamorphic setting of the base metal deposits and attemptsto relate this information to previous regional studies of the Kanmantoo Group. Estimates of pressure and temperatureof peak metamorphic conditions based on silicate mineral stabilities are considered in relation to various silicate and sulphidegeothermometers which have not previously been applied to rocks in the Kanmantoo Group.

Jan 1, 1988

By Ehlert G, Steinlechner E

The paper describes a new process for filtration which combines the continuous operation of conventional vacuum filters with the low final moisture contents hitherto only achievable with plate and frame presses. The increasingly high portion of fine particles causes several problems in the filtration of copper concentrates. One drawback is that remarkable quantities of liquid are attached to the very fine particles because of their specific surface area. Furthermore, fine particles also reduce the size of the capillaries in the filter cake, thus increasing the critical pressure which any filtration system has to exceed to achieve the desired final cake moisture. The maximum filtration pressure of conventional vacuum filters is limited by nature itself and by practical aspects to approximately 0.75 bar. The hyperbaric filter combines the continuous operating principle with an increase in filtration pressure of up to 6 bar simply by placing the entire disc or drum filter inside a pressure vessel. The major machine components and process features are explained in the details of the paper. After extensive research and field testing, 23 ANDRITZ hyperbaric filters, with a total filtration area of 1968 m2 have now been sold. Seventeen of these units (1440 m2) are in commercial use and more units are, on order. Performance data on copper concentrates from plants in Australia, South America, Poland, Africa and North America are outlined in detail. Compared to vacuum filters, generally hyperbaric filters will reduce the final cake moisture of concentrates with 75 per cent

Jan 1, 1993

The Matakan Unit of New Ireland, Papua New Guinea is a highly fossiliferous lagoonal deposit containing numerous coal pods and lenses. The unit is strati graphically part of the massive reefal Lelet Limestone of Miocence age. These organic-rich sediments have a high hydrocarbon potential as evident from microscopical observations as well as Rock- Eval pyrolysis data. The coal is varied in regard to dominant macerals, vitrinite being predominant in some parts and pollen and spores present in sufficient proportions to constitute a cannel coal elsewhere. The highly fossiliferous carbo as Rock-Eval pyrolysis data. The coal is varied in regard to dominant macerals, vitrinite being predominant in some parts and pollen and spores present in sufficient proportions to constitute a cannel coal elsewhere. The highly fossiliferous carbonaceous sedimentary rocks associated with the coal are rich in pyrite expressed in the sulphur content (19.7 - 22.8%). A high primary productivity and anoxic sediment pore waters or just above sediment - water interface have given rise to sufficient organic matter accumulations to yield a potential hydrocarbon source rock. Atomic H/C ratios of the coals are between kerogen type III and type II mainly, expressing the mixed nature of the coal and that of the associated sediments is type II. Early generated hydrocarbons (exsudatinite) have formed from pollen exines filling the pollen cavities and in places filling micro- fissures in the surrounding vitrinite.

Jan 1, 1987

A model has been developed for the per iodical maintenance of bins used for hydraulic hoisting in mining of steeply inclining coal seams. This model gives a control plan for hoisting, bin switching and bin maintenance on a regular schedule.

Jan 1, 1977

The Gympie Province is a unique tectono-stratigraphic unit which does not fit into the overall palaeogeographic pattern of the New England Fold Belt (NEFB), and part of it has been proposed as an exotic terrane more closely linked to New Zealand. From E to W the Gympie Province comprises 6 distinct units which can be evaluated as suspect or exotic terranes.

Jan 1, 1990

By D Macfarlane, T McMorran

  This paper describes the design and construction of the upper section of the Pike River Mine Access Road. The road extends 11 km from Logburn Road alongside Big River on the West Coast of the South Island of New Zealand up Pike Stream to the new mine portal on White Knight Stream (Figure 1). This new road starts on alluvial terraces, then partially follows an old logging road before entering virgin bush and traversing the true left bank of a steep sided gorge on Pike Stream some 50 - 100 m above the stream before dropping down to the mine entrance. Its development has been an extended process from route selection, consenting through to design and construction.   The paper focuses on the 1 km section of road between the Amenities Area (Figure 1) and the portal. This section of road is a steep section through the gorge, principally on Conservation estate, and has presented the most challenges and required the greatest effort to obtain the regulatory approvals, prepare the design and to construct. This paper outlines the history of the challenges faced and how the road was successfully developed.

Jan 1, 2007