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One major aim of the operation of Aberfoyle's matte fuming pilot plant was to assess refractories performance in the process working vessel, a SIROSMELT furnace. High wear rates were expected and whether these could be tolerated was an important question. During operations a range of refractory types was evaluated in both insulated and water cooled furnace designs. Furnace operations enabled lining wear measurements to be made. Results confirm that existing technology can solve any expected refractory problems. Design aspects that should be included in commercial furnaces are shown.

Jan 1, 1984

By McNicol M. D

Petroleum exploration in onshore Gippsland was directed in the 1950s and 1960s towards plays in the basal Latrobe and Strzelecki Groups, but these became forgotten in the 1970s with the Latrobe play discoveries offshore. The principal explorationists of the time were Woodside Oil and Arco Ltd, who then departed the scene after drilling some 18 wells without major success. In the late-1980s successful hydrocarbon finds in equivalent age Otway Group sediments in the Otway Basin were made and in early 1990 Tyers Petroleum began investigations into Strzelecki Group prospects as applied to the onshore Gippsland Basin. Some 18 anticlines have been mapped, based on shallower coal exploration drilling in the Latrobe Group, which from seismic and gravity evidence are believed to unconformably overlie similar anticlinal structures in the underlying Strzelecki Group. Strzelecki targets of interest within drilling depth are the basal Tyers Conglomerate/Rintouls Creek Sandstone Formations which outcrop in the north of the Latrobe Valley and are analogous to the Pretty Hill Sandstone in the Otway Basin. In addition, intra-Strzelecki Group targets similar to Heathfield and Windermere Sandstone Members are also considered to be present. Good source rocks are abundant including coal seams and carbonaceous sediments of Neocomian and Jurassic age, which lie within the oil window. Seal is provided by the overlying Aptian-Albian aged volcanogenic sediments. The Tyers/Rintouls sandstones - a target in the Woodside/Arco wells, with two exceptions, were not reached. Encouraging intra-Strzelecki shows were reported in many of the wells. Basal and intra-Strzelecki porous quartzose sandstones remain one of the few untested plays left in the Gippsland Basin and, in the onshore, merit extra attention as they he within the oil window at economically drillable depths.

Jan 1, 1992

The Paracale gold region had been known for hundreds of years, but the first professional attempts to work the lode and alluvial deposits were made only in the 1890s by the London-based Philippines Mineral Syndicate. Complex ores, transportation problems, and the Philippine Insurrection halted operations. Ultimate success went to American firms, though Frank Karuth's Philippines Mineral Syndicate had pioneered the field.

Jan 1, 1987

The Newmont Waihi Operations mill has undergone significant growth over its life. Initially designed as a single SAG mill operation, the circuit has been progressively upgraded since 1988 from a nameplate capacity of 600 000 tonnes per annum to the current rate of 1.3 million tonnes per annum. With future mining potential there is renewed interest to increase the processing rate even further. Over the next twelve months five sustaining capital projects will be undertaken and two major eco-efficiency projects will be completed. With the exception of the large grinding mills, most equipment on a gold treatment plant is replaced after 10-15 years. Waihi Gold mine has been operating for 14 years and has just recently received approval to replace equipment in five main areas; carbon elution, carbon regeneration, scats crushing, intertank screens and variable speed drives. Each project has been justified on improved process efficiencies and operating/maintenance cost savings. The two eco-efficiency projects involve a water balance model and a cyanide optimisation project, both of which are Corporate key performance indicators (KPI).

Jan 1, 2002

The reactions between molten aluminium and cryoIite have been determined from a material balance of all components involved in the process. The interpretation of results were supported by x-ray diffraction studies of the evolved vapours, quenched electrolyte samples, and side-reaction products.The most important reaction involves the formation of both Na2F (sodium subfluoride) and chiolite in the fused electrolyte. The Na2F accelerates vaporization of the melt. Some AIF (aluminium monofluoride) may also be formed but the proportion of this is much less than for the former subvalent compound.

Jan 1, 1968

By Gottlieb P, Sutherland D, Jackson R

The QEM'SEM system for automated image analysis of mineral samples is described. Details of the equipment are given together with information on the methods of measurement. Finally some practical applications are described where QEM*SEM has been used for the solution of metallurgical Problems.

Jan 1, 1989

The treatment meIhods selected for the concentrator at Cobar Mines Pty. Ltd. called for a high degree of automatic control of both the grinding and flotation sections.The resulting concentrator layout includes a central control room overlooking both grinding and flotation sections. The control room houses process recorders, controllers, and indicators. together with motor stopstart stations and alarms.Plant instrumentation includes load cells and variable speed hydraulic drive feeders for feed-rate control of autogenous mills, together with nuclear density gauges, differential flow transmitters, and pneumatic control valves for water and pulp density control.Flotation cell pulp levels are controlled by floats and pneumatic actuators; flotation reagent controls include magnetic flowmeters and time-operated solenoid valves.

Jan 1, 1969

A saturated, metal-free solution of alum can be used as a fiocculant to speed up the sampling procedure during a geochemical survey of stream silts.

Jan 1, 1969

The placer mining industry of the West Coast region of the South Island is based largely around the production of alluvial gold, although other valuable minerals are also present. Since the first major discoveries in 1864-65, reported gold production has totalled around 264 t (8.5 Moz). During the past 10 years, annual production has totalled around 1460 kg (47,000 oz). It is anticipated that gold production over the next three years will continue at a level of 1400-1800 kg.   Annual gold production peaked during 1866 at approximately 17,170 kg (550,000 oz) and has not exceeded 100,000 oz since 1885. This reflects the ease with which gold was won from shallow, rich deposits that were present at many localities. Subsequently, there has been a general decline in the availability of this type of deposit, a trend that will continue in the future. This paper outlines the present state of placer mining in the West Coast region, gives some historical background to the industry and briefly predicts future trends.

Jan 1, 1997

Solar Salt, Lunar Ambitions I Bauerti The title of this paper is `Solar Salt, Lunar Ambitions'. It is largely the result of a lack of imagination and a tight deadline. I was seeking a catchy title to convey the image of being 'here' and wanting to get `there', with `there' being a long way away and our being held 'here' by powerful gravitational forces. I tried `Solar Salt, Lunar Landings', but that implied we had already reached `there' when, on reflection, we had not. A colleague suggested 'Solar Salt, Luna Park' which is a fun park in Sydney and, I must admit, there was appeal in the image of having embarked on a wild roller coaster ride with stomach-wrenching twists and turns and the only reward being a pair of sweaty palms, and a feeling of nausea. That's sometimes how it feels when you launch into change. In the end I settled for the more sedate `Lunar Ambitions'. It contained that suggestion of hope and continual striving which are central to the idea of best practice. I will discuss our experiences in this area shortly, but I would firstly like to provide some background to our business. The salt industry is steeped in history and tradition. As one learned commentator observed, common salt is 'a substance seemingly too ordinary to think about, yet it is the oldest of man's raw materials and the basis of some of his newest inventions' (Multhauf, 1978). From ancient times, salt was recognised as a key necessity of life and it has played a role in the rise and fall of governments throughout history. The Romans recognised its importance when they gave their soldiers money regularly to purchase salt, hence our modern word 'salary'. Today, while culinary use remains important, the main consumer of salt is the chemical industry (Figure 1).

Jan 1, 1995

By Hughson B

The need to prevent the sterilisation of coal stems directly from the fact that it is a non-renewable resource. In N.S.W. a vast amount of coal resource is located under major public utilities such as freeways, railways, stored waters, pipelines carrying gas, water and sewage, and transmission lines. Total extraction has occurred under freeways, transmission lines and pipelines with little or no damage. Where damage has resulted, the cost of restoration was only a small fraction of the value of the coal recovered. However, coal at present is being sterilised and perhaps lost for ever under stored waters and railways. If engineering solutions are available for mining under these improvements economically and with maximum safety, then coal should be extracted and utilised to the benefit of the State.

Jan 1, 1986

Lower Miocene Maryville Coal Measures at Waitewhena Coalfield, in the Taranaki coal region, include seams of sub-bituminous coal up to 4 m thick. During coalfield exploration Fletcher Challenge Ltd drilled ten cored holes, all of which encountered at least one seam. Coal quality is variable. Ash ranges from six to 12 per cent and sulphur from 0.5 to three per cent. A basal seam, overlying the Lower Mokau Sandstone, appears to extend throughout the area under investigation. A rider seam, of variable thickness, closely overlies the main seam in most drillholes. The rider converges with the main seam to the north and vertical trends in coal properties suggest that the seams are united in some locations. A less extensive seam sometimes occurs at the top of the coal measures beneath the Upper Mokau Sandstone. The lithostratigraphy of the intervening coal measures is complex, and coexistence of fluviodeltaic, lagoonal/lacustrine, and marine depositional environments is provisionally inferred. Lateral variations in coal properties (clastic derived ash, volatile matter, inertinite, hydrogen), thickness of the sedimentary parting between the basal seam and rider, texture of the coal measure sediments, and distribution of the upper seam all indicate persistence of a relatively low lying northeast-trending zone which may have been structurally controlled. Available data indicate that coal measure accumulation was terminated by marine transgression from north to south.

Jan 1, 1987

Where vertical or near vertical faces are required in open excavations in soils and rocks, some form of stabilization of the 'cut is often necessary. Stressed anchors either alone or in combination with steel, timber or concrete-lagging are often an economical and versatile means of providing support. Stressed anchors are also-a very economical means of anchoring a wide range of structures such as dams, cranes, transmission towers, retaining walls, spillway aprons, bridge piers; and - stacks. The anchors need not be stressed always on installation.other than to proof load them. A number of examples illustrate some of-the more practical aspects of.the design and construction techniques used. No new methods of design or construction are involved, but merely some consolidation of the engineering design, soil and rock mechanics,thinking applied to the stressed anchor tech- nique.

Jan 1, 1971

A clear understanding of the meanings of terms is important when discussing a project. Whether it is a submission, an investment study, a feasibility study, an environmental impact statement, an estimate, a tender, a contract, or a close-out.report, the need for all parties involved to understand what is under discussion or what has been written is paramount. The clarity of definition and the level of understanding can affect the outcome of the project. It is vital that all parties know what is wanted, what is expected, and what it will cost. This paper draws attention to some of the problems that beset many projects, clients, project managers and contractors, and it is hoped that its presentation will encourage us to pay more attention to defining what it is that is required. Ultimately we should all be the richer for having defined and understood the requirements at the beginning rather than at the end.

Jan 1, 1990

Australia has been an important producer of zinc minerals and metal for many years.Late in the last century Edgar A. Ashcroft, a versatile and enterprising electrical engineer proposed the treatment of zinc rich ores by roasting, followed by leaching to extract zinc, purification of the solution and electrolysis of the purified solution to produce zinc. Residues from the leaching operation were to be smelted in a lead blast furnace to recover lead, silver and gold.Ashcroft (1897-98) and (1898) has.given us a most interesting record of the attempts made at the Sulphide Corporation's plant at Cockle Creek near Newcastle, NSW, to put his ideas into practice. In spite of the best efforts of all concerned, including the use of electrolysis of aqueous chlorides and sulphates, zinc could not be deposited consistently and the project failed although lead smelting continued until 1922 (Woodward, 1965, p. 158). Based on later experience with Broken Hill materials the presence of undetected cobalt in the solutions was the likely cause of the inability to deposit zinc (Kirk and Othmer, 1956).

Jan 1, 1985

By McGaffin I, Loah J

PT Newmont Minahasa Raya (PT NMR) is an Indonesian joint venture subsidiary of the Newmont Gold Company of Denver, Colorado, USA. PT Newmont Minahasa Raya operates a 700 000 tonne per annum gold plant in the Minahasa region of North Sulawesi, Indonesia. At full capacity the plant is expected to produce an average of 150 000 to 180 000 ounces of gold per year until the year 2007 based on current existing reserves.Exploration began in 1986 and high grade mineralisation was discovered in 1988. Subsequent drilling defined a resource of approximately 2000 000' ounces. Reserves as of 1 January 1997 were 7 035 000 tonnes grading 8.46 grams per tonne, for 1 913 000 contained ounces. Metallurgical testwork commenced in 1991. Construction of the plant started in late-1994 and the first gold was poured in March 1996.

Jan 1, 1997

By Phillips D. N, Herbert H. K, Fletcher A. C, Lewis R. K

Quartzite is a common feedstock used for the production of silicon by reduction at high temperatures in a submerged electric arc furnace. Silica fume, formed as a by-product in this process, contains crystalline silica in the respirable fraction. The crystalline silica in the fume represents entrained quartz derived from unreacted quartzite raw material within the furnace. A knowledge of the fragmentation of quartzite feedstock, in response to thermal disaggregation in the furnace, is important in feedstock selection to help minimise (a) the amount of crystalline silica in fume, critical from an occupational health and safety perspective, and (b) impurity levels necessary to achieve the highest possible purity of product silicon. In this study, a series of quartzites has been assessed in terms of the above requirements and correlations drawn between mineralogical and chemical characteristics. Alkaline solubility correlates with grain-size and level of stored strain in the quartz matrix. Grain-size affects the surface area available for attack while stored strain enhances the chemical reactivity of the strained matrix as well as profoundly influencing the disaggregation and microfracturing characteristics of strained grains and, hence, available surface area for chemical reaction.

Jan 1, 1995

In a previous paper of this series (1) ,t it was shown that during the creep of single crystals of lead, deformation proceeded to some extent by means of slip on the octahedral plane. This was demonstrated by the formation of slip lines on the surface of the specimens. At first, a few broad bands appeared after a small amount of extension had taken place; then, as extension proceeded, more and finer lines made their appearance until the whole of the specimen surface was covered.The present paper deals with the process of deformation of the creep specimens as revealed by X-ray examination..By the use of this method, the changes taking place in the crystal structure can be observed.EXPERIMENTAL METHODThe method of preparation of the specimens, their size and the purity of the lead employed have been reported elsewhere (1). At frequent intervals, the specimens were dismantled from the test rack and X-ray back reflection photographs were taken. The specimens were so marked and set up on the X-ray machine that the same spot on the specimen surface was always examined.Copper radiation was employed, the tube voltage and current being 45 kV. and 25 m.a. respectively and the exposure time 2 hrs. The slit diameter was 1 mm.

Jan 1, 1941

By D Craw

Previous studies of alluvial gold in Otago and Southland placer deposits have suggested a gold-mercury association for some deposits derived from Caples Terrane schist, whereas alluvial deposits on Torlesse Terrane basement typically have no mercury. A regional study of gold from Otago Schist vein deposits from both Caples and Torlesse Terranes has revealed the presence of both Au-Ag and Au-Ag-Hg alloys in both terranes. Au-Ag alloy (3 - 4 wt per cent Ag) is typical for gold found in most Torlesse vein deposits, and Au-Ag-Hg alloy (3 - 8 wt per cent Ag, 2 - 8 wt per cent Hg) is found in many Caples vein deposits. Au-Ag-Hg alloys are not exclusive to the Caples Terrane, however, as Au-Ag-Hg alloys with up to 4 wt per cent Hg are found in vein material from the Torlesse-hosted, HydeMacraes Shear Zone. In addition, not all Caples-hosted deposits have a gold-mercury association; gold grains from the Carrick and Invincible gold fields have no detectable mercury. The present study characterises gold compositions from various hard-rock vein deposits and has potential for determining placer-source relationships.

Jan 1, 2003

The Melanesian Outer Arc, extending from. Papua New Guinea to Fiji, developed as a result of interaction between the Australian and Pacific plates throughout the Tertiary, and the following stages are recognized. ,a, Formation of island arc tholeites above a west facing subduction zone in the Lower Tertiary. fit Emplacement of mainly calcalkaline volcanics above an east facing subduction zone in the Upper Miocene and Pliocene. ontinued east facing subduction coupled with fragmentation of the arc from the Pliocene onward. Alkaline and Mg-rich volcanism occurred in addition to continued calcalkaline activity. Tre Upper Miocene and younger volcanism is into five arc segments on the basis of geographic position and nature of the magmatism. The calcalkaline Bismarck arc extending along northern New Britain and including small islands to the west. The alkaline Tabar to Feni arc, north of New Ireland. The Solomons arc, including Bougainville and the western part of the Solomon slands. Volcanism is largely _.alcalkaline, but Mg-rich varieties occur the Solomon Islands. roe New Hebrides arc, extending from the -astern Outer Islands of the Solomons through Vanuatu. Both calcalkaline and :alkaline volcanics are representeo. alkaline and calcalkaline Fiji arc.

Jan 1, 1987