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By James CH

For drainage sediment to be used as a successful sampling medium in reconnaissance geochemical surveys, the length of any dispersion train from a typical target must be great enough for it to be detected by a widely spaced sampling pattern, and must also be homogeneous enough to avoid it being missed by the unfortunate selection of a random low value sample. Elements which occur in stream sediments in the form of discrete heavy minerals present two special problems in this regard. Since the element is concentrated into a few particles, the medium is extremely heterogeneous, which makes representative sampling impossible unless very large samples are taken, while the high specific gravity of such grains leads to their being concentrated in traps along the stream bed. Several ways of overcoming these difficulties have been suggested. Among these the "schlich" test, in which heavy material obtained by panning is taken for analysis is among the most popular. However, the results of the present study indicate that while this method improves the nature of the patterns obtained, they are still far from satisfactory. Alternative methods of sample preparation, including the taking of light material for analysis, appear to provide better answers to the problem. In the area studied this approach eliminated most of the "noise" associated with the data obtained by other methods, as well as giving an extended dispersion pattern.

Jan 1, 1986

By I M. Platten, Y Xie

Narrow vein gold mineralisation generally contains both fine (<100 ¦m) and coarse (>100 ¦m) gold particles. The in situ size and shape, deportment, distribution and abundance of the particles controls deposit sampling characteristics, grade distribution and metallurgical properties. Particles can range from individual disseminated grains, clusters of particles and masses above 1 cm in size. At each end of the coarse-gold to fine-gold spectrum, the samplability of a deposit ranges from relatively simple for fine-grained disseminated gold particles, through to extremely difficult for very coarse particles. Deposits generally show a background grade of mineralisation dominated by disseminated fine gold particles. Drilling will resolve the background grade well, though is likely to considerably understate the grade related to the coarser gold particles. Gold mineralogy has a significant impact on metallurgy, with key factors affecting recovery being particle size, deportment, liberation parameters and silver content of gold minerals. For coarse gold particles the focus should be on liberation and the early removal of the particles from the mill circuit by gravity concentrators and gold traps. Finer particles will require more grinding to liberate prior to flotation or cyanide extraction. The determination of gold particle sizing is thus required to minimise evaluation and geometallurgical uncertainty and lower project risk.

Jan 1, 2008

The Warraua and Mount Poole Inliers form part of a discontinuous series of basement complexes in the northwestern corner of New South Wales. The Inliers comprise mainly clastic sediments of low metamorphic grade (Wonominta Beds) and minor sills, dykes and intrusives, particularly within the Mount Poole lnJier. The Warratta rnlier has received attention due to the occurrence of auriferous quartz-veins where reef mining activities havetaken place.The deformational history of the Warratta and Mount Poole Inljers is characterised by a continuous subhorizontally WSW-ENE directed compression. Deformation was associated with the development of NNW-trending and steeply west-dipping major faults, which bound or biscct the inliers. Chevron folds and a penetrative axial planar cleavage characterise the deformational architecture and document crustal shorterung of at least 40 per cent. In zones adjacent to the major faults and within pelitic and semi-pelitic uruts, a multiple deformational evolution becomes apparent, comprising two events (D1 and D2). Deformational structures considered significant in this study were the result of D1. Tight, northeast-vergent fold patterns FI' and associated axjal plane cleavage SI' and reverse dip-slip movements at major faults indicate early northeast-directed thrusting during D1. This was followed by dextral strike-slip deformation displayed by tight, recumbent folds, en-echelon fold patterns (F2'), a northeast trending crenulation cleavage (52'), and two sets of second order faults, the latter showing high angular relationship to the major faults. A final stage of the deformational history (D2) is represented by WSW-ENE trending kink folds (F2).Auriferous quartz veins, predominantly occurring within pelitic and semi-pelitic units, were generated syntectorucally during the early deformational event (D1) in the course of commencing development of cleavage (S2'). Vein textures point towards vein formation by repeated hydrauJjc fracturing and fracture healing (crack-seal process), and by simple accretionary vein growth. Folded pelite-dominated horizons, considered as low permeability units, are suggested preferential sites where migrating metamorphic Ouids pooled and were trapped, causing high fluid pressure.Hydraulic fracturing and vein precipitation was controlled by lithology and structural constraints such as cleavage.K-Ar dates of approximately 440 Ma (Benambran Orogeny) marking the peak of metamorphism, and coinciding with the development of cleavage S1', also indicate the time of auriferous quartz-vein formation. A period of deformation of at least 30 Ma is proposed for the development of cleavage S1', as constrained by K-Ar dating and the intrusion of a syntectonic granitoid, the Tibooburra Granodiorite.

Jan 1, 1992

By Shiels O. J

The major Permian coal deposits of N.S.W. are in the Sydney-Bowen Basin and associated small deposits occur in structurally isolated areas; a further deposit is present in the Oaklands Basin. - The Sydney-Bowen Basin in New South Wales comprises the sub basins, the Sydney Basin and the Gunnedah Basin. Coal measures in these basins are near the top of the Permian succession and within and below an underlying marine sequence. The coal deposits can be conveniently described in units in which the coal geology is homogeneous. The Clyde Coal Measures and Yarrunga Coal Measures contain no seams of economic significance and occur beneath the marine beds in the south of the Sydney Basin. The Greta Coal Measures are economically significant and represent a brief interlude in the marine sequence in the north of the Sydney Basin and equivalents are present in the east of the Gunnedah Basin. The Tomago Coal Measures crop out above the marine sequence east from the Lochinvar Anticline and dip southeast to uneconomic depths. The Newcastle Coal Measures are historically and economically very important and overlie the Tomago Coal Measures and these measures will continue to be important although future mining will be faced with greater depths. To the west of the Lochinvar Anticline the Singleton Coal Measures, equivalent to the Tomago and Newcastle Coal Measures, crop out. This unit represents the thickest development of coal measures in the State and has a very large potential for both open cut and underground mining. Equivalents of the Singleton Coal Measures, the Black Jack Coal Measures and the Booroomin Group crop out on the east side of the Gunnedah Basin and probably are widespread across the Basin. They have less economic potential than the Singleton Coal Measures. In the southwest of the Gunnedah Basin, Illawarra/Singleton Coal Measures crop out over extensive areas and possibly have a large potential for underground mining under low cover. The Illawarra Coal Measures are exposed along the western margin of the Sydney Basin and thicken as they dip into the Basin across a shelf. The outcrop area is currently mined and the shelf has considerable potential for future mining. The highest rank coals in the State are in the Illawarra Coal Measures in the south of the Sydney Basin. The deepest coal mining is in this area and its continuing success is of great importance to the future exploitation of the resources of the Basin. The Tomago, Newcastle, Singleton and Illawarra Coal Measures extend into and meet in the central area of the Sydney Basin but they are under thick cover and are not considered to be economic at present. Permian coal measures occur in isolated areas in the New England Fold Belt and have limited economic potential. The Oaklands Basin in the south of the State contains a large reserve of low rank coal.

Jan 1, 1975

By Hatherly P, Holt GE, McNally G

The current methodology for delineating and subsequently evaluating coal reserves is based on the use of vertical drill holes and surface based geophysics/geology. These techniques have three major problems, these being respectively:-a) Vertical drill holes can only provide a small sample of the coal seam and stratigraphy. Therefore the planar variation in coal reserve and environment parameters can only be approximated.b) Although surface based geophysics has had its fair share of success in recent years, there are still environments which have masked the finding of major structures.c) Access to drill sites is difficult at some locations due to mountaineous terrain, standing water and environmental impact.

Jan 1, 1985

By Sowerby BD

The CSIRU Division of Mineral Engineering is developing various techniques for the on-line determination of moisture in coal and coke, and some instruments are now commercially available. These techniques permit accurate and rapid determination of moisture in materials directly on conveyor belts or in bins. The most promising techniques for direct on-belt measurement of moisture in coal are capacitance and microwave transmission. A non-contacting under-belt capacitance and gamma-ray backscatter technique has determined moisture in coal to better than 0.5 wt'/. in field tests at BHP Stockton Borehole Colliery, NSW. Mineral Control Instrumentation Pty Ltd have been licensed to manufacture the capacitance gauges and have installed five commercial units in the coal industry and other industries. Microwave transmission techniques have an advantage over the under-belt capacitance technique in that they are not sensitive to vertical segregation of moisture in coal on the conveyor belt. A laboratory prototype of a microwave transmission gauge has been constructed and tested. Microwave techniques, based on a measurement of attenuation and phase shift, are under development and are expected to be field tested in 1987. These new techniques will enable a wide range of thickness changes to be accommodated. Capacitance and microwave transmission methods are unsuitable for materials of high electrical conductivity, such as coke. CSIRO is therefore developing a fast neutron and gamma-ray transmission technique, which is proving very accurate in laboratory tests. This technique overcomes many of the limitations of thermal neutron moisture gauges and it is expected to be field tested in 1987.

Jan 1, 1987

Mining software systems have provided a basis for integration of resource, survey, and design functions. They can similarly provide a basis for incorporating ground conditions into the process.Exploration and mine geologists have a prime role to play in this process, extending their responsibilities further across the geological spectrum, into exploration of ground conditions, analyses of results, and assessments of their implications for mining. Ground conditions are as much a part of the geology of a prospect or mine as its mineralisation, and can have critical imnlicationa for mining.

Jan 1, 1993

By Warner RE

SINCE 1952, when Elliott et a/ first applied the Sherwood correlation for flooding in chemical absorption towers to blast furnaces numerous investigators throughout the world have followed their example and much research effort has been spent to tighten the correlation and recently to extend investigation of flooding to side gas entry conditions. The widespread use of the Sherwood concept of flooding has been such that even the word itself has become an integral part of blast furnace nomenclature. The evidence for the applicability of Sherwood's relationship has been that the flooding limits calculated from blast furnace parameters lie approximately on the Sherwood line. However, the values of many of the variables for the blast furnace calculation are only estimates and at first sight one may wonder at such 'close' coincidence when some of the estimated parameters entering the Sherwood correlation are raised to the power of three or more, as for the bed porosity and the liquid surface tension. It is felt that the explanation of this result lies in the logarithmic: nature of the plot and/or the fortuitous can- cellation of the errors of the estimates in the calculations coupled with the fact that blast furnace fluid ratios lie within a very narrow range of values. The foregoing considerations should in their own right place doubt on the correctness of the Sherwood type flooding correlation applied to the blast furnace. Additional doubt regarding the existence of the Sherwood type flooding in the furnace has been cast by the results obtained in the Tokyo University experimental blast furnace. From the reasoning of both Standish and Colquhoun (p. 20) and Warner (p. 23) it is deduced that flooding in the traditional sense will only normally occur in the upper bosh (somewhere near the mantle), following softening as discussed by Palella et a/ on p. 75, and flooding in that zone is likely to result in furnace irregularity. On the other hand, the concept developed by Warner of slag hold-up above the raceways as a stable phenomenon not affecting furnace regularity is a process unique to the blast furnace and is not described by the Sherwood flooding theory. Recognising the considerable practical implications of slag hold-up above the raceways, this note further explores the physical process of slag hold-up. We envisage that bed of coke above the raceways in almost all blast furnaces would contain some slag held up by the gas pressure gradient. In general the slag would be contained in a ring and gas would bubble through in its ascent through the furnace. The force supporting this slag is the pressure gradient and obviously -much of the blast pressure is dissipated in supporting this structure.

Jan 1, 1975

The moisture content of clean coal contributes significantly to the product's transportation costs, handleability characteristics and/or energy value. A major contributor to the total moisture is the ever increasing proportion of fine coal in

Jan 1, 1994

By Swain H. D, Kay R. L

Assessment of mineral reserves in any ore- body hinges on both mineralisation characteris- tics and the economics of extraction. The mineral reserves statement depends on interpre- tation of diamond drill information by geolo- gists, determination of the production plan and operating costs by mining and metallurgical engineers and prediction of future income by economists. The techniques used to generate the mineral reserves statement for Bougainville Copper Limited in 1969 are described and the accuracy of predictions discussed. Preliminary results from a geostatistical reassessment are comp- ared with the ore zone model, blast hole data and concentrator reconciled production results.

Jan 1, 1979

By Russell P

Polyurethane resin (PUR) is extensively used in almost all coal producing countries. On the local scene, PUR components suitable for underground application were selected and subsequently, trials were carried out at several coal mines. This paper describes the work at Pikes Gully Colliery (B.P.3Coal), where water flow rates of up to 4.5 m (1000 gallons) per minute, were reduced to 1-1.5 m /minute at the tirst stage of application. Subsequent trials were carried out at West Cliff Colliery (Kembla Coal and Coke). A variety of PUR chemical mixtures were tested in coal ribs and in the roof of intersections and roadways. The trial results are presented with all particular details. Using the PUR injection method, the roof, at the most difficult intersection, was stabilised and 'de-bonded' roof bolts were re-sealed. At Pikes Gully and West Cliff Collieries, 2 tonnes and 3 tonnes of PUR chemicals were injected, respectively. The technique, primarily based on German experience (Bergwerksverband), was used by Delta Control Systems Pty. Ltd. ACIRL was closely associated with the trials, which were monitored by installation of the measuring Stations.

Jan 1, 1986

By Grano S. R, Lauder D. W

Investigations on the oxidation behaviour of chalcocite and its rejuvenation by hydrogen sulphide ion have been undertaken. Chalcocite oxidation was measured using X-ray photoelectron spectroscopy (XPS), zeta-potential and by dissolution in et

Jan 1, 1997

By Aspinall T. O, Bell L. C

Increased awareness and stricter enforcement of regulatory requirements for adequate rehabilitation of surface mining sites has made environmental planning an essential part of strip mine planning. Rehabilitation is site specific and should be based on data which relate to that site. Cost-effective spoil pile design to minimise erosion is an important part of rehabilitation. Spoil pile design is an integral part of strip mine design. QCT Resources Limited has provided a postgraduate scholarship toward research in this area. The controlling factors of spoil pile design are post-mining land use, drainage requirements and degree and rate of erosion. The extent to which mine design is controlled by these factors is determined by regulatory requirements. To plan acceptable rehabilitation programs, erosion processes must be accurately modelled, and a range of erosion prediction models are available. Useful prediction models can be placed in two categories with the first category containing soil loss prediction models which can be used to predict the amount of soil lost from an area over a short or long term basis. Models in this category include the Universal Soil Loss Equation (USLE), Water Erosion Prediction Project (WEPP), Griffith University Erosion and Sedimentation System (GUESS) and Chemical, Runoff and Erosion from Agricultural Management Systems (CREAMS). The second category contains topographic evolution models which give an indication of the long term morphological development of a formed surface subjected to erosion processes. Models in this category include "Topog", Willgoose's Physically Based Catchment Evolution Model and Areal Nonpoint Source Watershed Environment Response Simulation (ANSWERS). The USLE has been used in the agricultural field for soil loss prediction. To apply the equation to mine sites in Central Queensland, it is necessary to understand the factors affecting erosion at the sites. This understanding should allow the variables of the equation to be quantified. The rainfall factor applied in the USLE is independent of engineering design or soil management techniques. The factor of spoil erodibility is dependent on the material's physical and chemical properties and can vary from site to site. In the equation, the topographic factor, cover and management factor and conservation practices factor can be varied by design to reduce erosion on rehabilitated areas.

Jan 1, 1991

By B Walker, A Robertson, C Wels, S Fortin

A background characterisation study was carried out in the Sangre de Cristo mountains, New Mexico, to: quantify naturally occurring contaminant loads from mineralised areas; define site-specific background concentrations; and to determine key factors controlling spatial and temporal variations in contaminant concentrations. The study included a comprehensive sampling and testing program (paste pH/EC, ABA, leach extraction tests) of soil/bedrock from mineralised areas (including erosional scars), and a ground water and surface water quality monitoring program in selected mineralised watersheds. Results demonstrate that high concentrations of contaminants occur naturally in ground and surface water draining the mineralised area of the Red River basin. The erosional scars were found to represent the major source of acid rock drainage (ARD) (~66 per cent) in this area due to: high rates of weathering and erosion, which continually exposes sulfide-bearing outcrops; and high rates of run-off as a result of high elevation and lack of vegetation. The scar material is generally very acidic (paste pH ranges from 8.5 to 1.5; average = 3.6) with highly elevated concentrations of sulfate and leachable metals. The composition and concentration of leachable metals vary significantly, not only between scars but also within a given scar. While all streams draining the various scar watersheds are highly acidic, each has a characteristic æfingerprintÆ of sulfate and metal concentrations. Most of the run-off from the scars infiltrates into alluvial debris flow aprons and reaches the Red River via groundwater flow.

Jan 1, 2003

By Pratt V, Davis K

Challenges facing middle management in the 1980's and beyond are not confined to business matters such as industrial relations, government and legal constraints, corporate takeovers, and commodity marketing. More particularly they deal with people issues and the interrelationship of corporate/ family relationships. There is a need for corporations to acknowledge the growing conflict between corporate/family roles being brought about by such matters as equal opportunity, double professional marriage partnerships, personal mobility and the increasing stress faced by managers as a result of current demands and expectations being placed on them. While the main responsibility for managing professional life as well as the relationship between professional and private life rests with the individual executive, corporations nevertheless have a major responsibility to assist these executives in this management process. Corporations in Australia are taking steps to address this situation but much more needs to be done. This was highlighted in the March 1985 "Middle Management" course with its associated Spouses Programme presented jointly by Australian Mineral Foundation and The Australian Administrative Staff College. Effective communication is at the heart of the matter but no amount of training on this subject will bear fruit unless there is an associated commitment by executives to improve the effectiveness of their communi- cation process both in their corporate and family roles.

Jan 1, 1986

By Leahy G. J, Moxon N. T, Nicol S. K

Experimental work is described in which extremely dilute aurocyanide liquors are treated with novel surface-active complexing agents to produce a hydrophobic aurocyanide species. Subsequent aeration of these liquors causes accumulation of such species at the air-water interface and the aurocyanide complex is transferred to a froth concentrate. A detailed performance assessment of this process is made and this knowledge used in the design of a pilot plant facility. Early results indicate the feasibility of the selective recovery of aurocyanide ions from reclaimed residue dam water (approximately 0.2ppm Au) with upgrade ratios of the order 180:1. A further study was made applying ion flotation to the recovery of gold from a carbon-in-pulp (CIL) feed liquor (approximately 1.0ppm Au). The probable economics of this process compared to conventional CIL processing is also described. Successful development of countercurrent ion flotation for concentrating solids-free gold solutions may offer a lower cost alternative to existing gold ore processing technologies, or in more secondary applications such as concentrating dilute gold solutions or heap leach runoff. The technology may also have more generalised applications to other heavy metal process- Ing.

Jan 1, 1991

By Schonert K

The throughput of a HP-roller mill is determined by the acceleration of the feed material within acceleration zone and introduction into the compression zone. Both processes depend on the internal friction and the friction of the material on the roller surface which is influenced by the surface structure and adhering of material. The particle motion in the acceleration zone has been investigated with high speed videos showing the effect of the centrifugal force and the slip on the roller surface. The throughput is discussed in the term of the specific throughput which can be approximated by a linear function characterised by the throughput number and the throughput elasticity. The throughput number is a helpful measure for investigating the influence of the feed material and the surface structure. The experimental results give some guidance for chosing an optimum corrugation profile.

Jan 1, 1993

By Postupack C

A major problem that has continued to plague the surface and underground coal industries is blast induced damage to the coal seam. Blasting Analysis International, in conjunction with a number of other organizations, has continued to address this concern through 14 years of field research in 68 full-scale production environments worldwide. Compiled results were obtained from varying field conditions. These included single and multiple seam coal mines, horizontal, rolling and steeply dipping coal seams and varied borehole diameters (ranging from 102 to 381 mm) and when using various explosive formulations. Results are discussed in detail along with the tools, test methods and analysis techniques to identify and quantify the problems. Over ten major causes of coal damage were identified. A number of practical and economic recommendations are presented that can benefit the entire coal and blasting industry especially in commercial operations whose economic growth relies heavily upon recovering an undamaged coal seam.

Jan 1, 1995

The Drummond Basin is a large intracratonic basin which developed in central Queensland during Late Devonian to Early Carboniferous times. It is postulated that the Drummond Basin developed as a foreland basin, to the west of a probable west dipping continental margin volcanic arc and subduction zone. The Drummond Basin sequence has been s,ibdivided into three tectono-sedirnentary cycles. Cycle I forms the base of the sequence and comprises thick sequences of intermediate to felsic volcanics and proximal volcanolithic sediments. The volcanics, particularly in the northeast of the basin, occur in separate sub-basins around what were probably isolated eruptive centres. In contrast, the rocks of Cycle 2 and Cycle 3 have been deposited during episodes of broad, basin wide subsidence. Five major igneous episodes, some of which may be co-magmatic, are recorded in the eastern Drummond Basin and environs between the Late Devonian and the Early Permian. The first and second episodes occurred during the Late Devonian to Early Carboniferous and are represented by the volcanics in Cycle 1 and Cycle 3. The third episode involves the intrusion of granitoids of Early Carboniferous age into the Drummond Basin sequence. These occur in the Ukalunda area and are related to gold mineralisation at Ukalunda and Valhalla. Episode four includes the felsic volcanics of the Bulgonunna Volcanics. This episode does not appear to he broadly auriferous but gold mineralisation does occur in possible basal Bulgonunna Volcanics at Mount Coolon. The final episode includes a suite of granitic intrusives which intrude the Bulgonunna Volcanics and which are considered to be co-magmatic with them. These intrusives do not appear to be generally associated with gold mineralisation. Gold mineralisation is widespread in the north- eastern Drummond Basin and environs. It is probable that the gold mineralisation is concentrated in epithermal cells during the Late Devonian to Early Carboniferous volcanic cycles. This style of mineralisation appears to be related to tectonic setting in modern analogues.

Jan 1, 1989

By Chapman G. J

Mining operations require detailed and precise methods and procedures for the optimum selection of ore from waste. A fundamental procedure applied to achieve this selection is accurate sampling. The key parameter to accurate sampling is an understanding of the degree of heterogeneity of the key element contained within a sampling mass. This paper will describe the methods applied for the calculation of the fundamental sampling error and the techniques used to achieve a representative sample in the Fimiston Open Pit, Kalgoorlie.The utilisation of Pierre Gy's sampling theory has optimised the blast hole sample quality and quantity for submission to the assay laboratory. This has resulted in reduced cost and optimised assay reliability in statistical terms. Similarly the analysis of exploration drill holes for resource definition has optimised drilling procedures in terms of the drilling method, sample length and sample quantity.

Jan 1, 1993