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By Laing W. P, Neill D. M, O&apos

The Reward polymetallic massive sulphide deposit occurs 35 km south of Charters Towers, adjacent to the Highway gold deposit (Fig. 1). It is hosted within rhyolitic lavas and interlayered volcaniclastics of the Cambro-Ordovician Mt Windsor Volcanics. Reward is a "blind" deposit discovered in 1987 after a long history of exploration by various companies in the area. The main pyrite dominant massive sulphide body occurs under 100m combined thickness of Tertiary fluviatile sediments overlying deeply weathered gossanous volcanics. The exploration case-history provides a striking example of how geological and structural models can be built up almost exclusively from drill information. Four different styles and ages of mineralisation are present: 1) volcanogenic Cu+Pb+Zn+Ag+Au massive sulphides of probable syngenetic origin; 2) remobilised Cu+Au in massive pyrite of metamorphic/deformational origin; 3) supergene and 4) oxide Cu+Au mineralisation of weathering origin. The massive pyrite body, containing chalcopyrite lenses, transects the stratigraphy and is inferred to contain in excess of 5 million tonnes. Overlying the primary mineralisation a supergene chalcocite rich zone contains a measured/indicated resource of 634,231 tonnes of 6.77% Cu which includes 287,000 tonnes of 1.32 g/t Au and 18 g/t Ag. In addition a measured/inferred oxide resource of 309,000 tonnes of 5 g/t Au and 27 g/t Ag overlies the supergene zone.

Jan 1, 1989

Incompetent ore and country rock have caused stability problems in longhole open stopes. Fully grouted pre-placed cablebolts have reduced these by preventing ground relax- ation and joint dilation to maintain a self supporting rock structure. Larger atope spans can now be opened with the same or smaller pillar. Mining methods are expected to become less dependent on original ground conditions. Effect of spacing, orientation and stress distribution along the cablebolt is not fully understood at this stage and requires more Observation.

Jan 1, 1977

By Fraser CJ

Stability control plays a prominent part in the planning and execution of coal winning in the deep open cuts in the Latrobe Valley operated by the State Electricity Commission of Victoria (SECV). Different stability mechanisms affect the individual overburden and coal faces. These are the classical rotational slip in overburden and the three-dimensional tetra- hedral wedge or planar block slip in the coal faces. The stability of the overall batters is affected by the so-called "block sliding" mechanism, which is unique in Australian open cuts. The basal stability of the open cuts is affected by pressure from water in confined aquifers underlying the coal being excavated. This paper describes each of these mechanisms and the current monitoring and con- trol techniques practised by the SECV.

Jan 1, 1982

By C M. Sennitt, M J. Spadafora

Systematic field evaluation of known gold and clay occurrences in South Korea has led to the recognition and discovery of both high and low sulphidation gold-silver epithermal systems. These are associated with Cretaceous acid-intermediate volcanic centres in the southern parts of the peninsula. The high sulphidation deposits such as Seongsan and Kohung are characterised by pervasive silica-alunite-dickite-pyrophyllite alteration with anomalous arsenic geochemical signatures. Gold mineralisation is associated with fine grained marcasite and pyrite. A low sulphidation quartz vein system observed at the Tongyoung mine comprises multistage colloform banded quartz-carbonate assemblages, with minor manganese and base metals. Gold and silver occur as electrum and tellurium minerals. Some deposits such as Gasado and Dogcheon display both high and low sulphidation alteration assemblages. Early pervasive silica-alunite-pyrophyllite alteration caps formed by acid fluids with a significant magmatic component, occur above cryptocrystalline colloform banded vein systems. The quartz vein stage hosts the precious metal mineralisation and appears to have been deposited by later neutral fluids generated in part through mixing with meteroric water.

Jan 1, 1999

By Turner T. M, Jorgensen F. R A

The tendency of the concentrate to ignite was studied using four techniques, namely, laminar flow furnace, fluid bed, thermal analysis and boat-in-furnace. Exothermic activity occurred at two temperatures: minor activity in the vicinity of 200¦C, major activity at 330-350¦C. The low temperature reaction was due to the ignition of a small amount of free sulphur while the major activity was associated with the ignition of the sulphide minerals, notably pyrite. To avoid ignition of the sulphide minerals, the gas temperature should not exceed 300¦C and the oxygen content of the gas phase should be as low as possible. It was shown that little of the arsenic in the concentrate entered the gas phase during drying.

Jan 1, 1987

By Murphy MW, Klaric SD

The history, operation and design of the Secor continuous rod production process is described. The effective operation of the plant is influenced by accurate monitoring and control of molten metal properties, mould release application, coolant application and composition and correct setting of all operating parameters. The continuity of operations, which is an essential feature of this type of plant, is also greatly influenced by the service life of wear parts in the operation. This paper deals with three principal wear parts which come into direct contact with copper during operation, these are:

Jan 1, 1985

By Laage L. W

line fires pose a serious threat to the safety of all underground personnel. Early knowledge of the location of a fire in a complex underground mine would greatly reduce the associated risks by enabling miners to choose the safest escape routes, rescue teams to concentrate searches where survivors would most likely be found, and fire fighters to select the most efficient route to the fire and the most effective fire fighting strategy. Once'the fire's location is known, other related aspects of the fire can also be inferred, such as intensity, fuel, and growth Rate.

Jan 1, 1988

By Coin CDA

From a study of coke samples obtained from the tuyere level of four Australian Blast Furnaces, the nature of in-furnace coke degradation has been investigated. At the periphery of the raceway is a concentration of fines and the lump coke appears dull and rounded. However coke from the deadman is angular and relatively undegraded. Cokes made from higher rank coal appear to suffer preferential attack of the reactive maceral derived component (binder). The coke from lower rank coal appears to be attacked non-preferentially by the solution-loss reaction. Initial attempts to simulate these phenomena have given results consistent with these findings. From chemical analysis of the tuyere probe samples there appears to be a relative increase in carbon and decrease in-.sulphur and phosphorous between stockline and tuyere level. An overall decrease in coke mineral matter derived material was noted and associated with this was a significant gasification of silicon. Consequent formation of silicon carbide was noted.

Jan 1, 1981

By Mouritz M

Ventilation characteristics and the occurrence of nocturnal surface inversions have been investigated within the Mount Whaleback open cut iron ore mine at Newman in Western Australia. When winds are light and/or nocturnal surface inversions form within the pit, episodes of atmospheric stagnation can occur with resultant accumulation of dust, diesel exhaust fumes, and sulphur dioxide evolved from spontaneous combustion of pyritic shale. Nocturnal surface inversions were recorded outside the mine on more than two-thirds of nights. Inside the pit, inversions were much less frequent - occurring on roughly 20% of nights when they were observed outside - and much weaker - the maximum temperature difference being 5 C¦ over 210 m inside the pit compared with 15 C¦ over 150 m outside.

Jan 1, 1988

Detailed studies of mineral paragenesis, isotope and trace-element geochemistry, and physical mineralogy at Mount Morgan are compatible with deductions by Geopeko Ltd geologists concerning field relationships in the mine area. Considered together, field and laboratory data suggest that the Mount Morgan deposit originated from a shallow, intrusive, acid volcanic dome similar to those which produced the Kuroko-type deposits in Japan. At Mount Morgan, however, interaction with sea water was much less, the sulphides were concentrated rather than forming a group of deposits, and only the throat of a breccia vent is pre- served, so that only the lowermost parts of Kuroko-type deposits can be compared with the Mount Morgan mine. A final difference lies in the presence at Mount Morgan of a quartz diorite adjacent to the ore. Mineralogical data are compatible with post-ore intrusion, possibly up an earlier volcanic fissure.

Jan 1, 1974

By Rennie J. W

In the first five years of longwall mining at Pacific Colliery, special techniques of goaf sealing, gas drainage, goaf edge ventilation and goaf sampling were developed and used to o crcome the concurrent problems of spontaneous combustion and high methane emissions. The English-inspired back-return face ventilation system was modified to suit Australian mining methods and was first used as part of a 'Y' ventilation system and more recently was used with a 'U' system of ventilation. In conjunction with this ventilation system, the maintenance of a sealed goaf area was an essential element in the control of the spontaneous combustion in the goaf.

Jan 1, 1988

Australia contains a variety of iron ores, differing in grade, chemistry, size distribution and genesis. While a proportion of this ore is used world-wide as blast furnace lump, much of the material mined is high grade fines, requiring agglomeration (usually sintering) before blast furnace reduction. Sintering studies initially concentrated on the production of ferrous material of high iron content, coarse size and sufficient cold strength. In recent years research involving pilot plant sintering, precise test procedures and mineralogical analyses has focussed on the additional sinter properties of hot strength and reducibility. Aspects of mineralogical studies applied to iron ore sintering are described.

Jan 1, 1989

By G J. Corbett

Magmatic-related low sulfidation hydrothermal ore systems at plate margins exhibit distinct spatial and temporal zonations which can be used to aid mineral exploration and development. Low sulphidation systems at all crustal levels exhibit the same paragenetic sequence of events: early breccia formation, followed by quartz - secondary feldspar sericite/illite veining, then mineralisation, and final argillic overprint. This sequence of events is interpreted to reflect the initial emplacement of melts at high crustal levels, and the progressive cooling of that melt and release of magmatic constituents into a circulating hydrothermal system.   Low sulphidation systems in the south-west Pacific region exhibit a vertical zonation in deposit types: from porphyry copper-gold at deep levels, quartz-sulfide-gold at mesothermal to deep epithermal levels, carbonate-base metal gold at mainly epithermal levels, and epithermal quartz silver-gold at shallow levels. It is interpreted that the characteristics of each of these styles of deposits is produced by mixing with circulating waters of different physio-chemical compositions.

Jan 1, 1995

By Reid T. W

This paper describes the results of investigations into the relationship between specific gravity and chemical composition in the Cockatoo Island orebody, In the early investigations the samples were classified into groups according to porosity. This resulted in high, medium and low porosity groups, the latter being further subdivided into ore and waste. Whole number tonnage factors were assigned to each group. In the later investigations the reciprocals of bulk specific gravity and true specific gravity were ex- pressed as linear combinations of iron, silica and alumina using stepwise regression. The efficiency of the models as predictors was tested by dividing the data into two sets; one of which was used to calculate the regression equation and the other to test the efficiency of the equation as

Jan 1, 1976

By Forster I, Thilo A, Dean AK

A prototype production tool capable of operation in the hole sizes (

Jan 1, 1988

The treatment plant of the Gold Mines of Kalgoorlie Ltd. is situated on the Oroya South Lease, on the Eastern edge of the Kalgoorlie Golden Mile.It was designed and erected by Messrs. Alex. Stewart and Company, in consultation with Mr. Harry Hey, and was completed in November, 1937.Its original capacity was 9,000 tons of all-sulphide ore per calendar month, l?ut the plant was extended in October, 1939, to treat 13,000 to 14,000 tons per month of mixed sulphide and oxidised ore.Recovery of the gold is accomplished by cyanide treatment, followed by flotation of the cyanided residue, roasting and cyanidation of flotation concentrate and precipitation of the gold from the cyanide solutions. In the cyanide section, the crushed ore is finely ground in cyanide ,solution and the pulp is agitated to dissolve further gold. It is then thickened and filtered. In the flotation section, this filter residue is conditioned with S02 gas and a pyrite-gold concentrate recovered by flotation.This concentrate is roasted and then cyanided.KALGOORLIE ORE DEPOSIT.The Kalgoorlie ore deposit occurs within a wide area of Pre-Cambrian rocks, ,and consists essentially of two series of basic igneous rocks known as the older greenstone series (calc schist) and the younger greenstone series (quartzdolerite- greenstone) . The older greenstone is a group of lava flows. The younger intrusive greenstone series can, in the main, be classified as a chloritised and carbonated...

Jan 1, 1948

By Lownds C. M

Several classes of commercial explosives and blasting agents behave non-ideally, especially in diameters near their critical diameter. A direct and convenient measure of non-ideal behavior is the detonation velocity (VOD); if the VOD is less than the ideal value, usually obtained by calculation, then the explosive is detonating in the non-ideal mode. Such lowering of the VOD is usually due to both lateral loss of energy and post-CJ release of energy. The second of these factors, namely slow release of chemical energy, is of most interest in blasting. While the observation of a low VOD clearly suggests slow reaction of part of the explosive composition, it does not necessarily mean that the energy is lost to the overall rock-breaking process. The partition of the energy of the explosive into various useful and wasteful categories is considered. Simple models of energy partition in blasting, and of explosive reaction kinetics, are presented. The models consider the effect of explosive type and rock type, the explosive being described in terms of the most common phases namely liquid, air bubbles, porous ammonium nitrate, dense or crystalline ammonium nitrate, and aluminum. Over a range of combinations of the above phases, the model predicts reasonable critical diameters and VOD's. Results are presented which show the effects of non-ideal detonation on fragmentation and heave in different rock types. Conclusions are drawn about those blasting conditions in which ideal behavior is beneficial, or Disadvantageous.

Jan 1, 1990

By Lynch P

Oaky Creek Coal Pty Ltd. currently mines high quality coking coal from both underground and open cut operations at its Oaky Creek Mine. Coal is transported by rail to the Dalrymple Bay Coal Terminal south of Mackay and to the Gladstone Coal Terminal. Oaky No.1 Underground Mine, Open Cut and Highwall Mine have concentrated on seams from the German Creek Formation, one of the major productive coal measure formations in the Bowen Basin Coalfields. (Fig. 1) location map.

Jan 1, 1998

By A C. Robertson

Over the past decade there has been continual change in the way that mines have been managed and the component roles of those people who make up the total mine management system. Major issues have included the change in the business structure of mining companies, the change in on-site infrastructure, increased personal liability of managers for the safety and health of employees and increasing social and environmental pressures on managers and their staff. This paper looks at the changing roles of two of the many groups of professionals associated with the mining industry - the equipment supplier and the mining consultant. The profiles of the ACME Group Pty Ltd, suppliers of ventilation equipment and ancillary canvas and plastic products to the mining and construction industry, and Tennent, Isokangas Pty Ltd, Consulting Mining Engineers, are presented.

Jan 1, 1998

By S N. Nyoni, K C. Corin, C T. O’Connor

Considering future water scenarios, as influenced by the increasing scarcity of water and the move towards sustainable process engineering etc, the closed water circuit becomes an important point of study in metallurgical operations, such as in milling and flotation. However, a deterrent in the use of recycled process water is often a lack of understanding of the effects of the accumulation of dissolved ions and other process chemicals. Recovery of the valuable minerals may be impacted by the concomitant complex mineral-pulp chemistry interactions. Literature indicates that these interactions are not necessarily antagonistic to process outcomes. Wet milling using steel media results in the dissolution of Fe from the media, the rate of which is dependent, inter alia, on the type of media and the chemical conditions of the aqueous environment in the mill. The pulp-phase interactions of dissolved ions with sulfide minerals may result in significant changes to the chemical conditions in the mill, which may subsequently impact negatively on the flotation recoveries. To understand the effect of these interactions in the context of the processing of sulfide minerals, this study seeks to consider the effect of three factors, viz mineral type – pyrite (Py) and galena (Gn) -, milling media of different compositions – forged steel (FS), 21 per cent high chrome and ceramic media -, and water chemistry, viz, deionised water (DI) and synthetic plant water (SPW). Ceramic media and galena are used for the respective control cases where the milling media and sulfide mineral contribute no Fe species. Using DI as a control case, a high ionic strength case is used to mimic the changes in water chemistry for a closed water circuit. Batch flotation tests are used as a diagnostic tool to determine the effects of these media-water-mineral interactions to investigate correlations between the chemical reactions occurring and chemical species present during the milling process and the ultimate flotation performance.

Aug 24, 2022