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For the past five years the University of Queenslandhas, through its various workshops, been preaching to Australia that there was a potentially hazardous situation from earthquakes for urban Australia. A few people outside The University accepted this, but largely the warnings fell on deaf ears.The 1989 Newcastle earthquake changed that per-ception. The most important lessons to emerge from Newcastle were (i)the realization that in continental areas small earthquakes cause widespread damage:(ii)the local geology of an area is of great importance in the damage done by an earthquake.These two factors clearly indicate that, in the future, we must take far greater account of the "Urban Geology" of an area. This paper discusses the need for urban geology and its impact on seismic risk and compares that with the traditional methods of assessing seismic risk.

Jan 1, 1990

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 Lawson F

A rotating disc geometry has been used to provide a uniformly accessible surface for a kinetic study of the cementation of the metals cadmium, lead and silver from dilute aqueous solutions. This work is an extension of studies carried out on the Cu/Zn and Cu/Fe systems for which the rection rate was found to be completely solution-phase mass-transfer controlled. When the amount of material deposited was greater than 0.2 to 0.4 mg/cm2 there was an apparent enhancement in e which is attributed to the formation of a roughened deposit. This same phenomeon was obseived in the Cu/Zn Cu/Fe systems. Again, the rate of reaction of each system investigated was found to be solution-phase mass ,..~sfer controlled.

Jan 1, 1970

By S Hapugoda, A Edenton, L Lu

The blast furnace cohesive zone has a profound impact on hot metal productivity and quality, fuel consumption, operational stability and the lining life of the blast furnace. The high temperature properties of ferrous burden materials determine the configuration and location of the cohesive zone and have therefore attracted particular attention. While numerous standard testing methods are in use to assess the quality of ferrous burden materials for the blast furnace, these simple tests are generally conducted under fixed conditions, which often represent the extreme situations encountered by the burden materials in the blast furnace. Furthermore, none of these simple tests provides information on the high temperature properties of the burden materials, such as their softening and melting properties. CSIRO is equipped with a fully computerised testing facility to characterise the high temperature properties of ferrous burden materials under realistic conditions similar to those encountered in the blast furnace. This paper will first review the CSIRO softening and melting test method and then discuss the softening and melting properties of a variety of blast furnace burden materials, including sinter, pellets and lump ore, and their implications for blast furnace operation.

Nov 8, 2021

The Canada Centre for Mineral and Energy Technology (CANMET) /Calgary Coal Research Laboratory and the National Research Council in Ottawa established a joint working research group with industry to develop and test various computer models for application in surface coal mining operations in western Canada.The first part of the paper deals with the problems the group experienced during the past two years especially having model specification and requirements defined and understand site management practices.The second part of the paper deals with site specific development of general mine model for TransAlta Utilities' Highvale Mine in Alberta. Described here are the development of an interactive truck/shovel model for their three pit operation, selection and application of dragline model for tandem operation with the extended bench method, criteria for operational model of the five seams operation with selec-tive mining approach.

Jan 1, 1985

By Paine GG

The in-situ retorting of shallow oil shale deposits is an attractive alternative to the material handling problems of conventional open pit mining techniques, which involve removing overburden, fragmenting and transporting the shale to a fixed retort, and finally disposing of the hot spent shale.For in-situ retorting to be successful, the oil shale has to be fractured and the fragmented rock expanded into a void, to allow controlled propagation of a flame front through the in-situ retort. The principles of cratering with explosives have been used to develop a process for the in-situ fracturing of a thin oil shale deposit overlain by a formation of porous rock. The overlying porous rock formation is first compressed by explosive charges to create voids in the porous rock. The oil shale is then fragmented and pushed in to the voids with separate explosive charges. This paper discusses methods of creating voids in porous rocks with minimal surface disturbance, and then methods of obtaining the most uniform fragmentation of the shale. The whole process can be completed, in practice, in one blast. The results of an experimental blast are presented, and possible modifications are then discussed.

Jan 1, 1985

In the past ten years or so there has been a renewed interest worldwide in the processing of refractory gold ores. The Archean province of Western Australia contains both numerous and major gold deposits, and has a long history in the development and practise of treating refractory ores (eg Blaskett and Woodcock, 1953). Depletion of shallow oxidised ores in recent years has re-focused attention on deeper sulphidic ores, and as a consequence has renewed interest in treatment methods for those ores which are refractory. Mineralogical factors he at the heart of reasons as to why these ores are refractory, and are the key to designing and improving treatment options in the longer term. This paper presents an overview of mineralogical factors that are relevant to the processing of refractory gold ores in the Archean of Western Australia. It is based on a number of research projects and other work on a variety of gold deposits, mainly in the Eastern Goldfields region, carried out over the past five years or so.

Jan 1, 1991

By K Dudley, D Readett

The design of entrainment control processes in copper SX plants has been studied by use of models based on achievable plant performance. A number of alternatives have been assessed for their suitability in minimising the transfer of deleterious species from PLS into the electrolyte. The position of the wash (scrub) stage in the circuit, either before or after the loaded organic tank, has been the subject of considerable debate. The modelling shows that at ænormalÆ entrainment levels, the performance of the circuits are very similar. However at high entrainment levels the selection of the wash after the loaded organic storage has significantly lower transfer of contaminants. When considering the inclusion of a loaded organic coalescer the results of the modelling again show that the best circuit has the loaded organic storage/coalescer before the wash stage. The overall control of EW contaminants includes both a wash stage and an EW bleed flow. The total water use for these two flows is shown to go through an absolute minimum. The minimum flow rate is not greatly dependant on the total entrainment from the SX settlers. This can be a useful operating strategy if the quantity of high quality water for make up is limited by the capacity of the water treatment plant (eg RO). However the minimum cost option is to maximise the flow of water to the wash stage and minimise the EW bleed stream. The main driver for this is the cost of the cobalt sulphate contained in the electrolyte. Some results from the latest circuit modifications at the Nifty and Girilambone Copper Projects are presented to confirm the benefits of using both coalescing systems and a wash stage. The EW bleed has been reduced to a level that is less than the loss internally in the SX stage to stage entrainment. There has been an occasional need to add chloride to the EW to maintain sufficient concentration to act as a growth modifier.

Jan 1, 2002

By Demin SS

Slow seismotectonic movements along the in-clined deep fault zone under the compressional horizontal stresses are supposed to be the prin-cipal mechanism controlling the structure and processes in the active ocean margins. Within the scope of the plane strain problem a simple 2-D geomechanical model for the evolution of an island arc system is investigated. We consider a homogeneous elastic half-plane with a shea-ring surface crack. The key element of the model is viscous interaction between the crack sides, the viscisity varying with depth. The model dif-fers from the classical steady-state mode of subduction by nonstationary creep processes on deep faults and by possibly cyclical development of the transition zone.A numerical modeling of the stress-strain state within the island arc system through time was carried out using a semianalytical approach. The results of simulation are in good agreement with geological, geophysical, and seismological data.

Jan 1, 1990

Investigation of standard tests used to establish the decrepitation rating of Western Australian iron ore showed scatter in results which could be reduced by textural type sampling. Testing of individual textural types resulted in separation.of a range of decrepitation behaviour patterns. No unique correlation was established between water content in goethite, or between any single mechanism and breakage in shock heating. The latter depends rather on several mechan- isms whose operation is controlled by the texture of the ore. Texture studies were used successfully to predict decrepitation behaviour which could be related to orebody structure for mine planning, and blending for sales or processing requirements.

Jan 1, 1973

Coal seam methane (CSM) is an æunconventionalÆ gas resource that is becoming an important energy resource for Australia, especially along the eastern seaboard. It has been conventionally believed that methane in high rank coals was exclusively derived from thermocatalytic processes during decomposition of coal at elevated temperatures. However, recent re-interpretations of gas composition and isotope data have indicated that microbial methane generation may be one of the main processes responsible for the accumulation of commercially producible methane in some coals. In low rank (æbrownÆ and sub-bituminous) coals, methane (CH4) is mainly generated by microbial activity at low temperatures. The amount of this biogenic gas generated and accumulated in low rank coals depends largely on the rate of burial and depth. Most low rank coals are æunder-saturatedÆ with respect to their maximum gas sorption capacity. In contrast, high rank coals may be highly saturated due to extensive gas generation from both thermogenic and secondary biogenic processes. However, in basins where secondary biogenic gases have not replenished the thermogenic gas lost during basin uplift, the coals will be æunder-saturatedÆ. In many basins around the world, high CSM producing zones appear to contain secondary biogenic CH4 generated by microbes transported in meteoric water recharge through permeable coal seams. Biogenic CH4 generation requires the activity of a consortium of anaerobic respiring microorganisms, fermentative bacteria and acetogenic bacteria to break down complex organic molecules to simpler molecules having one or two carbon atoms, which enables methanogenic archaea to generate CH4. The two main methanogenic pathways in the generation of secondary biogenic gas from coal are aceticlastic reaction and carbon dioxide (CO2) reduction. In eastern Australian coals CO2 reduction appears to be the main process. The types of microbes that are directly involved in these processes are unknown because they have not yet been isolated from the coal seams. The CSIRO is currently investigating the processes of biogenic gas generation in Australian coals. Potential may exist to introduce appropriate microbes into deep coal seams to enhance methane saturation levels, gas sorption capacities and permeabilities.

Jan 1, 2004

By Mack JF

A metallurgical evaluation of the Argyle Kimberlite No. 1 (AKl) orebody has been carried out using a 40 tonnes per hour pilot plant. Pilot plant results, together with laboratory investigations provided a basis for the determination of process design criteria for a major treatment plant. Various sampling programmes were carried out to determine specific aspects in the evaluation of diamond liberation. Treatment parameters such as the top crush size, recrush size and the bottom cut-off size were investigated. A description of the pilot plant is given together with the design criteria for a 3 million tonne per annum treatment plant

Jan 1, 1984

By Sakurai F

Akita Zinc Refinery of Mitsubishi Metal Corporation (MMC) started operation in 1953 with a capacity of 560 tons of electrolytic zinc per month. Its capacity has been expanded gradually and reached 8,100 tons per month in 1973. However, present production level is about 6,500 tons per month due to the depressed zinc market. In 1963, newly developed sulphate roasting was incorporated for residue treatment. Since 1973, electric power from Ohnuma geothermal power station of MMC has been supplied in addition to hydroelectric power from Komata power station of MMC. At present, about 40% of power is supplied from our company's power station and the rest is from the power company. Recent customers' demands for zinc prod- ucts include various kinds of shape, weight and chemical composition of galvanizing zinc alloy. It is necessary for zinc producer not only to meet the requirements of customers but also to enhance the value of zinc product in order to expand the market of zinc.

Jan 1, 1987

Despite the research interest on non-cyanide gold lixiviants over the past three decades all the non-cyanide gold processes are still at the developmental stages with limited understanding on solution and pulp chemistry in some cases. This is partly associated with:the difficulties in measuring reliable equilibrium data for various gold(I/III) complexes with non-cyanide ligands; the lack of knowledge on mixed-ligand complexes; and different kinetic stabilities of gold(I) complexes with respect to disproportionation. This paper presents reliable equilibrium data for complex formation, dissolution, precipitation, hydrolysis and disproportionation reactions of gold(I/III) compounds with a range of non-cyanide ligands: S2-, HS-, S2O32-, SO32-, SCN-, SC(NH2)2, OH-, NH3, Cl-. Solubility of gold(III) compounds with non-cyanide ligands follows the order: Cl- > NH3 > OH-. In the case of gold metal the solubility order at a given temperature is MgS > Fe(III) or Cu(II) / Cl- > Cu(II)/NH3 > NaOH, but the solubility increases with increasing temperature. Rate of gold oxidation with different non-cyanide lixiviants depends on the oxidant, ligand and temperature and follows the general order of oxidants: Fe(III) or Cu(II) > X2 or OX- > O2 (X = halogen). In the case of metal ion oxidants oxygen is required to reoxidise Cu(I) or Fe(II). Some of the reported data on chloride and thiosulfate leaching of gold are presented to highlight the effect of additives and the copper, silver and sulfur contents of the starting material on the success of non-cyanide leaching processes.

Jan 1, 2004

By Bockhorst R. W, Christopher D. A

Over the past fifteen years, horizontal drilling in coal seams for advance degasification has become an established practice in the United States of America. Consolidation Coal Company pioneered the development of the horizontal drilling system and licensed the technology in the U.S. A. and to Du Pont (Australia) for commercial production. This paper discusses the most recent developments in the equipment design, especially the borehole telemetry system, known as the Downhole Drill Monitor (DDM).

Jan 1, 1988

Background BHP Iron Ore Pty Ltd is one of the major iron ore producers in the Pilbara Region of North Western Australia. The company manages three separate joint ventures; the Newman, Goldsworthy and Yandi joint ventures and two 100 per cent owned operations, Yampi and Jimblebar. The Newman operations constitute a mine site at Newman and a 426 km railroad to Port Hedland where there is an ore processing/port site. The Goldsworthy operations currently constitute a mine site at Shay Gap/Nimingarra, a developing mine site at Yarrie, a decommissioned mine site at Goldsworthy and an ore processing/port site at Finucane Island (Port Hedland). The Yandi operations include mining and processing facilities at site and a spur line to join the Newman Hedland railroad. Jimblebar operations are scree and bedrock mining near Newman and include mining, processing and a spur line to Newman where it joins the Newman-Hedland railroad. The Yampi operations constitute a mine/port site at Koolan Island (which is presently being decommissioned). The combined BHP Iron Ore operations produce approximately 46 Mtpa of iron ore. This paper will concentrate on the processes developed and applied for the decommissioning of the Goldsworthy site. The Goldsworthy site is on the northern boundary of the Pilbara Region and adjacent to the western extremity of the Great Sandy Desert. It is located approximately 110 km east of Port Hedland (see Figure 1). The area is generally of low relief with isolated low ranges. The mine site being within the Mount Goldsworthy range area. The geology of the area is essentially Archaean granite with Archaean banded iron formation becoming dominant within the ranges. The chief soils are hard alkaline red soils. The vegetation is essentially shrub steppe with the main hummock grass species being spinifex (Triodia sp). The climate for the region is semi arid tropical. The temperature ranges from a mean low of 15¦C in winter to a mean high of 40¦ in summer. Rainfall is episodic, occurring mainly throughout the summer as a result of tropical depressions or cyclonic activity. The average annual rainfall is approximately 300 mm and annual evaporation may exceed rainfall by up to 2500 mm. Goldsworthy Mining Ltd commissioned the Goldsworthy site in 1965/66. Goldsworthy was the first iron ore operation and associated town site in the Pilbara region. The mine development peaked in 1977 with the town population reaching 1400 people. In 1982 mining ceased and the mining operations were relocated to Shay Gap, 80 km east of Goldsworthy. The Goldsworthy town continued as the base for the railing operations between Finucane Island and Shay Gap. BHP Minerals acquired Goldsworthy Mining Limited in 1990. The population for the town of Goldsworthy at this stage was around 450 people. An assessment of the Goldsworthy site operations concluded that it was uneconomic to continue the operation of the site. The decision was made to transfer the base for railing operations to Port

Jan 1, 1994

By E Widijanto, A Srikant

PT Freeport Indonesia operates a copper-gold mine located in the remote highlands of Papua, Indonesia, about 3500 km east of Jakarta. Currently, the district produces about 240 000 tonnes per day (tpd) of which about 45 000 tpd come from the DOZ Block Cave and the rest is mined from the Grasberg Open Pit. Over the next ten years, ore production from large block caves in the area is expected to reach about 200 000 tpd, replacing a large part of the production from the Grasberg Pit. Block cave mining alters the hydrological characteristics of the area being mined and when the cave expresses itself at the surface in the form of subsidence, it increases the entrapment area for surface water. Operating a large block cave mine in a region with an average annual rainfall of 5500 mm in steep mountainous terrain and complex geological and hydrological features presents a challenging scenario for dewatering or depressurisation of the area. The high rainfall infiltration and entrapment in stacked mines operating within an essentially single orebody, coupled with the presence of fine-grained and clayey material within the draw points of the block cave, creates mud rushes or wet muck spills, which can endanger the personnel and interrupt production. This paper outlines the problems caused by high water inflow into the DOZ Block Cave and the efforts undertaken to ensure the safety of the miners and continued achievement of desired production rates from underground mining in the district.

Jan 1, 2006

The refractory industry in New Zealand is small, consisting of two main manufacturers - one at Huntly and the other at Kamo. Together these would have an annual refractory production of about 30 000 tonnes. The industries which use refractories include two steelworks, NewZealand Steel Limited and Pacific Steel Limited, the former is involved in continuous casting from sponge, iron and scrap steel and the latter is involved in ingot teaming from scrap steel and steel billets; One aluminium smelter, cement works, dairy companies, small foundries producing engineering requirements and many other small users. The New Zealand manufacturers produce refractories in thefire brick range, that is up to 50 per cent alumina content (ignited basis), based on indigenous raw materials and in the high alumina range up to 85 per cent alumina content (ignited basis) based on imported bauxites. All of the basic refractories high purity silica and high alumina low alkali refractories and many of the higher grade acid resisting refractories are imported.

Jan 1, 1976

By Jena, Anand S, Das R. P

Leaching studies were carried out on Indian Ocean manganese nodules using sulphuric acid as the lixiviant. By leaching the nodules with 8 per cent sulphuric acid for 12h at 100°C, copper and nickel could be completely extracted along with 50 per cent cobalt and 6.2 per cent manganese.94.2 per cent of the iron was also dissolved. To increase manganese and cobalt extraction, charcoal was used as a reductant. The role of charcoal was to reduce the manganese dioxide and render it soluble as manganese sulphate as well as to facilitate solution of the cobalt minerals associated with the manganese dioxide. Various leaching parameters were studied including acid concentration, amount of reductant, leach time, pulp density and leach temperature. It was found that by leaching the nodules with 10 per cent sulphuric acid at 100°C for 4h using 5 wt/wt per cent charcoal (0.05g of charcoal per g of nodule) almost complete extraction of copper, nickel, cobalt and manganese could be achieved. However, under these conditions all the iron present in the nodules was also leached.

Jan 1, 1989

By Cudmore JF, Rowlands D

Incidents associated with spontaneous combustion of coal have resulted in the loss of many lives and considerable capital and equip- ment. Nevertheless, the factors controlling the propensity of coal to spontaneous combustion are not clearly understood and there is a need for research to study the effects of rank, petrog- raphy, moisture contents, etc. This has been attempted in a study of the propensities of selected Queensland coals to spontaneous combustion. An adiabatic calori- meter was constructed to study the self-heating of a large number of coals. Chemical and petro- graphic analyses of the coals were determined and an attempt was made to relate these propert- ies to the self-heating characteristics of the coal. The results show a strong relationship between rank and self-heating characteristics and that petrographic composition of coal may also be of importance. Some observations on the application of the laboratory results to the practical situation are made as are recommendations for future research.

Jan 1, 1981