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HIGHWALL MINING - DECISION TO MINEUlan had completed operations in the first Open Cut area due to high stripping ratios and the presence of geological features which destroyed a significant portion of the coal in the upper part of the seam. The pit had been abandoned in 1994 and operations had moved to a new location to the north west.

Jan 1, 1998

By Blair JR

The tunnel alignments investigated for the Gosford Regional Sewerage Scheme are located in the Terrigal Formation and are covered for most of their length by a thick blanket of soil and weathered rock. The following techniques were found to be most effective in geotechnical investigations for tunnelling in this area: air-photo interpretation, seismic surveys to pinpoint drilling targets, in-situ measurements of strength,deformation modulus and permeability in cored holes, and the construction of rock- mass models. Cross-hole seismic modulus measurements, surface resistivity soundings and electric well-logging techniques were found to have limited applicability due to adverse local conditions.

Jan 1, 1976

By Ely K. W

On January 21, 1986, a methane ignition and subsequent mine fire occurred in the under- ground workings of the Jim Walter Resources, Incorporated No. 3 Mine located near Adger, Alabama. The fire, which began on a longwall face and eventually spread into the adjacent gob area, could not be extinguished directly and raged out of control for several hours. Sealing operations were begun underground by Mine Rescue Teams and the fire area was successfully sealed with the mine able to resume production in about one month. The No. 3 Mine liberated over sixteen million cubic feet of methane in twenty-four hours. The operation was unique, in that, the successful underground sealing of a fire in an ultra-gassy mine had not been attempted or com- pleted for several years. Maps and charts are included to give explanation of the typical data used to manage the recovery effort.

Jan 1, 1988

In order to fully understand why Amax Coal puts such extreme emphasis on the drilling and blasting programs at each of our mines, we must review the past. This paper will discuss the drilling and blasting techniques we used in the 1970s and their evolution to current practices. As time progressed, major changes influenced the surface mining of coal through new more restrictive governmental controls and local communities organising into groups with two goals in mind, one to shut down the mines and the second to try and get rich by making false and unjust damage suits against the mines. In virtually all of our midwest surface operations we have at one time or presently are facing litigation that has reached into the millions of dollars. Amax Coal has worked in co-operation with the United States Bureau of Mines in the areas of blast vibration, shot design, highwall safety, blast casting studies and many more. Today we are continuing to work with Dr David Siskind and his expert staff seeking answers to old and new problems addressing the blasting of overburden and parting seams.

Jan 1, 1995

By Moore A. J, Evans R

Blast vibration control and assessment techniques have been developed which supplement traditional charge mass scaling methods. The improved techniques, which can be used to predict air and ground vibration levels at the planning stage, and to assist in the control of blasting operations, have reduced the level of operating risk concerning blast vibration. In addition to such factors as charge mass, distance and blast vibration levels, these additional techniques take account of orientation of the blasting face, topographic shielding, wavefront reinforcement, and meteorological conditions. They have assisted in compliance with specified blast vibration levels for environmental licence and mining lease conditions, the reduction of blast vibration nuisance to residents in the area surrounding a mine, and control of building and rock structure response in adjacent areas on the mine lease area.

Jan 1, 1994

By Clarke RG

Renison Mine was developed as the first all diesel mine in Australia. The foresight of the early planners in committing the Mine to Decline access has paid dividends in the past two decades with Renison Mine establishing itself as one of the most productive underground mines in the world. The excellent productivity has also resulted from the development of mining equipment technology, both on the part of the equipment suppliers and through the coordination of the Mining, Automotive and Technical Design Sections at Renison Mine. Constant improvements in truck and loader design, the design of specific equipment to carry out specialized tasks such as installation of services, scaling and ground support and the conversion to electrically powered equipment have been ongoing at Renison. Currently, larger scale trucks are being investigated for ore and waste haulage due to increased haulage distances and production requirements. It appears as though an articulated low profile truck of around 50 tonnes capacity may provide the short term solution based on the performance data available.

Jan 1, 1982

By Grieveson P, Rajakumar V

The reduction of an ilmenite concentrate with coal at 1000, 1050 and 1100¦C was investigated using thermogravimetry and X-ray diffraction, optical microscopy and electron probe microanalysis of the product. The effects of temperature, coal particle size, addition of ferric chloride and preheating of the concentrate in argon on the reduction kinetics and mechanism were determined. The rate of reduction increased significantly with temperature and was enhanced by the addition of the catalyst. The morphology of the iron was primarily determined by the degree of weathering of the particle. Significant coarsening of iron was obtained in the dense particles by the addition of ferric chloride. The sequence of reduction and the enhancement in the rate of reduction by preheating the concentrate in an inert atmosphere are discussed.

Jan 1, 1991

By R F. Johnston, I D. Sommerville

This paper presents an overview of the researches carried out in our laboratory on the application of plasma in recovery of alloy elements from waste slags and the treatment of lean ores, which are examples of advanced materials processing. After briefly reviewing the early work on the reduction of nickel, chromium, manganese, vanadium and titanium oxides, and a short investigation of the reduction of titanium oxide from the slag resulting from the blast furnace smelting of a titanomagnetite ore, the paper concentrates on the more recent studies on the reduction of an Australian scheelite. In some of these experiments, aluminium was used in addition to carbon as a reductant, in virtually all cases complete reduction was achieved within a relatively few minutes even with carbon alone during plasma processing. It therefore appears that this technique provides a possible processing route to facilitate the recovery of valuable alloying elements from non-traditional sources, or to permit process step elimination.

Jan 1, 2000

By OÆBrien D, Priddle D

In order to avoid costly moisture penalties on coal shipments and to minimise rail freight costs, screen bowl centrifuges were selected and installed in the Mount Thorley Coal Preparation Plant for dewatering fine coal product. The Mount Thorley fine coal circuit consists of desliming the -0.5 mm (ww) fine coal in two stages of classifying cyclones prior to recovery by froth flotation. Provision has been made to bypass the flotation circuit with the classified flotation feed reporting directly to product and the centrifuge dewatering circuit has been designed to handle either flotation feed or flotation product. Major mechanical failures of the gearboxes and the ceramic tiling occurred early in the operation life of the machines which led to design changes being made to achieve satisfactory operation. This paper discusses the operating experience at Mount Thorley with respect to both mechanical and metallurgical performance of the screen bowl centrifuges since their installation in 1985.

Jan 1, 1989

In June 1992, the High Court of Australia recognised native title of the Meriam people over parts of the Mer Island in the Torres Strait as a form of common law. The Court also indicated that native title may have survived European settlement of the mainland Australia where it had not been extinguished by Governments and Aboriginal people have maintained their traditional connection with the land. The decision meant that two systems of land law were seen as existing side by side in Australia: ò one which derived from grants from the Crown under laws passed by Parliament; ò another which derived from the diverse laws and customs of the many Aboriginal groups in Australia.

Jan 1, 1996

Over the last thirty years production of heavy minerals from Australian deposits has dominated the world market. The main incentive has been to suoply the raw material for titanium dioxide based pigments. These ~ninerals include ilmenite, rutile, leticoxene and more recently, synthetic rutile. Inevitably the viabilit/ of developing placer type deposits has seen influenced by other heavy minerals present, such as zircon and monazite, but these have been of secondary importance. For most of the sixties and seventies, Australia supplied the 'najority of free world rutile and zircon, and a large proportion of the ilmenite. With the run-down of rutile- rich reserves in eastern Australia, the emphasis has s:iifted in several countries, including Australia, to fill }the gap with i l Wen i to and its derivatives, leucoxene, synthetic rutile and titanium rich slag. over the next 15 - 20 years, as high grade beach placers in Western Australia are mined out, less traditional sources for mineral sands products will be opened up. Low grade placers (particularly those dominated by ilmenite) will be reassessed in Australia, U.S.A., Africa and Asia, and exploration will shift from beach and dune environment, to heavy mineral concentrations in alluvials, lake deposits and continental shelf deposits. At the same time, production of anatase and bastnaesite will be expanded, as required, from the huge resources contained in carbonatites in 3razil, U.S.A. and China.

Jan 1, 1986

Green policies have gained momentum since the 1972 Stockholm Environment Conference. The environmental movement has influenced political initiatives both in New Zealand and abroad. Governments and international institutions have addressed local, regional and global environmental issues with varying degrees of success. New Zealand so far has not supported the United Nations' call for sustainable development in a,consistent manner.New institutions and new rules for resource management mean there are opportunities to look after the land in different and more ecologically sensitive ways than has happened in the past.The increasing influence of regional councils in resource management planning will have important implications for mining and mineral exploration. These trends are discussed and possible future events outlined.

Jan 1, 1990

By Russell J

A sustained drop in the grade of Mount Isa lead-zinc-silver ore occurred in mid 1980. It was decided to increase concentrator throughput from 200 000 to 240 000 tonnes/four week period to maintain budget metal production. To achieve this increase whilst maintaining acceptable grinding and flotation performance, crushing plant final product size had to be reduced from 100%-13mm to 1000-11.2mm. The goal in the crushing plant was to achieve a 20% increase in throughput with a 20% decrease in the top size of the product. This was achieved by operational changes to improve plant availability and optimisation of the existing crushing and screening equipment Performance.

Jan 1, 1978

By Scherbatsky VB, zon BM, Babushkin NM, Kitaev BI, Shabel&apos

The structure and hydrodynamics of the raceway zone of a blast furnace was studied on a cold model representing a sector containing two tuyeres. The model differed from the usual in that it was prov- ided with continuous flow of the coke layer at pre- determined rates, had provision for changing the tuyere parameters (diameter, protrusion, inclinat- ion) and irrigation of the layer with liquid. A combination probe was developed which per- mitted simultaneous measurement of the pressure field both across the area and through the height of the layer as well as determining the topography of the raceway. The velocity fields in the layer were measured with a specially made impulse thermo- anemometer. The determining criteria of the model were taken as the relationships between the energy of the blast and the particles, the dimensions of the raceway and the cross-section of the tuyere. The model established the effects of the tuy- ere structural parameters, blast parameters and amount of liquid products of smelting on the con- figuration of the raceway, the structure of the layer, pressure and velocity fields in the vicinity of the tuyeres and in the vertical direction through the layer. The properties of the raceway formation and the structure of the layer in motion have been clarified.

Jan 1, 1981

Until the early 1960s the world aluminium industry was dominated by six principle pro- ducers with integrated activities from bauxite mining to aluminium production. The growth in consumption of aluminium since that time and the emergence of additional producers has broadened the market for bauxite. In addition the increase in the optimum size of alumina refin- eries has influenced competing metal producers to unite in large joint ventures to minimize alumina costs. From these bases the paper examines present and likely future markets for Australian bauxite; differing marketing phil- osophies for serving those markets; factors influencing successful marketing; and the sources and relative strength of competition which Australia faces.

Jan 1, 1974

Western Mining Corporation (W.M.C.) operates a nickel refinery at Kwinana, 30 km south of Perth. The refinery commenced pro- duction in May 1970, with a rated capacity of 15 000 tpa of nickel metal. A hydrometallurgical route was chosen as the most expedient way to produce nickel metal at a time when world demand for nickel was outstripping the supply. Later events dictated that an increase in production from the refinery be achieved. To this end, matte produced from Kalgoorlie Nickel Smelter, which was commissioned in 1972, was used in varying proportions as a complement to the concentrate initially utilised as input to the refinery. The effect of matte addition was to increase the capacity to 30 000 tonnes of nickel per annum. This was accompanied by other benefits which were 1. reduction in energy consumption per unit of nickel produced, 2. improved metal extraction, 3. improved precious metal recovery, 4. reduced production of ammonium sulphate by-product. Refinery operating results for the years 1970 to 1983 show how matte feed has improved refinery performance in these areas.

Jan 1, 1984

By Ono K, Oishi T

Electrochemical determination of the oxy- gen partial pressure in the Fe-0-SiO 2 ternary systems saturated with solid silica was done by measuring the activity of oxygen in a silver bath in equilibrium with the molten slags using zirconia solid electrolyte galvanic cells. From the data obtained, the activity ~Faii.st composition relations were calculated

Jan 1, 1980

By Van Heuzen JA

The extensive deposits of brown coal in the Latrobe Valley form the major solid fuel resource in Victoria and are the energy source for most of the State's power generation. This paper describes the coalfield resources allocated for electricity generation and a potential sequential develop- ment of these areas in future years to supply future power stations.

Jan 1, 1982

By Fisher AEJ

On Sunday morning 7th November, 1976, at approximately 2-25 a.m., smoke was discovered issuing from the 1912 m long belt drift at Appin Colliery. A Clouth steel cord rubber belt approximately 940 mm in width had been installed in the drift in 1963 on the basis that no fire resistant steel cord belt was then available to operate on a single lift at the load and on the 160 gradient of the drift. Investigation showed that the belt drift was on fire and the usually downcasting drift was upcasting. Immediate fire fighting and rescue operations were instituted and the drift was sealed off. High expansion foam was pushed into the drift from the surface and the fire was brought under control. Recovery work resulted in the fire being put out and the drift open for walking traffic by, S-P0 am., on Wednesday 10th November, 1976. lie experience gained during the fire fighting and recovery operations led to recommendations in regard to future use of high expansion foam.

Jan 1, 1981

In the general planning of this area, provision was made for the distribution over the whole area as required of the following services:(a) Power and lighting from the substation distribution boards 'located in the winder house.(b) Miscellaneous electrical indicating, control and signalling systems.(c) Telephone lines from the main internal automatic exchange located in the changehouse, the town exchange to the automatic exchange and also direct lines from the town exchange to selected offices.(d) Compressed air from the incoming 16-in. air main. (e) Water, both unfiltered and filtered; and the disposal of the following effluents:(f) Sewage from the area to the town sewage system.(g) Changehouse shower water to the regeneration area.(h) Storm water to the general mine surface drainage system leading out to the naturally drained area north of the No. 8 Shaft.

Jan 1, 1957