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By Cheung L. C C, Maconochie A. P

SIROFRAG is a computer-based imaging system that quantifies the post-blast rock fragment size distribution in a muckpile in a mine environment. Improvements in blast performance and blast modelling are being hampered by a lack of a quick and objective method to evaluate the major result of the blast: the fragment size distribution. This is usually done by hand digitising muckpile photographs: a labour intensive and tedious process. SIROFRAG is being developed to quickly, cheaply and objectively provide this information. SIROFRAG is based on active stereo image analysis. It uses a light stripe to illuminate a muckpile and a pair of video cameras to determine the 3D nature of the scanned objects. The imaging system is based on a novel prototype scanning projector that allows images to he captured in full daylight. The Microsoft Windows based software controls the projector and interprets the captured images to provide a size distribution of exposed rock fragments.

Jan 1, 1995

By O. J. RICHARDS

The Wongawilli system of mining has been in use for over 30 years and has enabled high production rates and acceptable extraction ratios to be achieved in seams less than 4 m in thickness. A modification of the Wongawilli system has been developed to permit the use of a continuous miner and mobile equipment to extract a coal seam 6 m thick. Following physical and mathematical model studies the new mining method is now undergoing field trials at Collinsville, Queensland. Progress of the field trials to date has achieved 99% extraction of the upper slice by remote control operation of the continuous miner and established the feasibility of installing resin grouted wooden dowels in the coal floor to reinforce the coal septum. The method is explained in the text.

Jan 1, 1980

By Wright R, Stock E. C

The Windarra nickel deposits known to date comprise two sulphide orebodies located at Mount Windarra and South Windarra. These orebodies, which are 15 km apart, lie within an ultramafic complex at or near its footwall contact with a banded iron formation. The Windarra deposits are 270 km north-northeast of Kalgoorlie in West- ern Australia which was the centre of a major nickel exploration programme fol- lowing the discovery of nickel deposits at Kambalda in 1966. Surface indications of the Mount Windarra orebody were discovered in 1969 by Mr. Ken Shirley while prospect- ing the Laverton area for Poseidon Ltd. (then NL). The mineralisation was loc- ated by systematic prospecting for goss- anous material associated with aero-mag- netic anomalies and ultramafic rocks. The South Windarra deposit was dis- covered in 1971 by the Union-Hanna- Homestake Joint Venture, by exploring along the strike extension of the mount Windarra ultramafic-banded iron format- ion contact. A detailed ground magnet 1. Acting Operations Superintendent, Windarra Nickel Project, Windarra, W.A. 2. Senior Geologist, Windarra Nickel Project, Windarra, W.A. 3. Mine Geologist, Windarra Nickel Project, Windarra, W.A.

Jan 1, 1973

I am very pleased to be here at this seminar on carbon-in-pulp (CIP) technology for the extraction of gold as I am always interested to hear about any new development in any aspect of gold ore processing. We can expect to learn a great deal from the papers to be presented over the next few days. It is not my purpose to give a detailed description of the CIP process nor to give a complete historical review. However, in this opening address it was thought appropriate that I should mention some historical features and some technical factors to set the scene for subsequent papers. HISTORICAL NOTE Table 1 shows some interesting dates of the use of carbon in gold metallurgy in Australia. Mount Morgan used carbon after chlorination TABLE I Carbon precipitation in Australia 1891 Mount Morgan 1917 Yuanmi mine (Edmunds) 1934 Sons of Gwalia (Edquist) 1975-1980 Various pilot plants and small companies 1980- Various large and small plants

Jan 1, 1982

Attempt has been made to determine the nature of charge on activated carbon surface by studying the electro-kinetic properties of the carbon in the presence of cations, anions and aurocyanide solutions. The zeta-potential measurements were made in the presence of individual ions and also in combinations. The cations and anions chosen were those commonly associated with gold bearing ores in Kalgoorlie area. It was found that the iso-electric point of Norit Carbon was at pH 4.45; below this pH the charge was positive, while above, it was negative. In the absence of gold cyanide solutions and in the presence of individual cations the i.e.p. shifted to the alkaline range (pH 7.2-8.5) while in the presence of anions the i.e.p. was shifted to less than pH 3.5. In the presence of aurocyanide solutions, the iso-electric point was still in the acid region irrespective of whether anions or cations were present. The probable mechanism for such a behaviour has been attempted after measuring the specific conductivities of solutions before and after gold adsorption, by studies using the electron- probe-mirco-analyser, and S.E.M. on the carbon surface.

Jan 1, 1982

By Roe P, Lowell A

This paper outlines software development and design work carried out by Mincom Pty Ltd in collaboration with Capricorn Coal Management (CAPCOAL) for computer based design of rehabilitated strip mine landforms at German Creek Mine. Current developments and future application areas for this software are also discussed in relation to other mines in Central Queensland. The development program was initiated in response to statutory requirements placed on mining companies in 1990 to produce a five year Plan of Operations which was to include a contour plan of the final rehabilitated mine landform at the end of the five year planning period. This plan was to be submitted to the Department of Resource Industries (DRI) by 1 December 1990. Due to the limited time given to prepare the plan, a work program was formulated in collaboration with Mincom Pty Ltd to develop suitable software to carry out the design work and provide the required plans and quantities. The software had to include computer based methods to allow design of the proposed landform in line with the rehabilitation strategy adopted by CAPCOAL at the time.

Jan 1, 1991

Indigenous brown coals, which provide a readily available primary energy source, have played a significant part in the industrial development of Victoria. The deposits located in the Latrobe Valley compare in extent with other major deposits of brown coal in the world. Smaller but valuable deposits occur at Stradbroke, Gelliondale, Anglesea and Bacchus Marsh. Extensive drilling, aided by geophysical surveys, and detailed analyses of coal samples, have enabled the extent and quality of these Tertiary deposits to be Defined.

Jan 1, 1979

By Snowden C. T

B Lens Main is a scheelite orebody with an average dip of approximately 15¦ and thickness ranging from 1.5 to 6.0 m. The orebody is overlain by a banded section of ore and waste which tends to slab off if left unsupported. It was originally planned to mine a large portion of this orebody by room and pillar methods, with existing diesel trackless equipment. This, however, proved unsuitable for a number of reasons and the smaller scale method of slot stoping with hand machines and scrapers was employed. The following major problems were encountered. 1. The method was new to the mine and the work force, and had to be commenced quickly using existing or easily obtainable equipment. This is gradually being overcome by training, modification of procedures and introduction of more suitable equipment. 2. The slabbing from the hanging wall had to be controlled, either by support or by mining this low grade section and accepting the resultant dilution. This has been approached in a number of ways, depending on conditions and the method will have to be further modified as different conditions are encountered in new areas.

Jan 1, 1977

LESLIE BRADFORD GOLDEN JUBILEE ORATION "Not only a metallurgist but a scientist of the highest order" Leslie Bradford and the Australian Metallurgical Industry

Jan 1, 1987

By D Macfarlane, T McMorran

  This paper describes the design and construction of the upper section of the Pike River Mine Access Road. The road extends 11 km from Logburn Road alongside Big River on the West Coast of the South Island of New Zealand up Pike Stream to the new mine portal on White Knight Stream (Figure 1). This new road starts on alluvial terraces, then partially follows an old logging road before entering virgin bush and traversing the true left bank of a steep sided gorge on Pike Stream some 50 - 100 m above the stream before dropping down to the mine entrance. Its development has been an extended process from route selection, consenting through to design and construction.   The paper focuses on the 1 km section of road between the Amenities Area (Figure 1) and the portal. This section of road is a steep section through the gorge, principally on Conservation estate, and has presented the most challenges and required the greatest effort to obtain the regulatory approvals, prepare the design and to construct. This paper outlines the history of the challenges faced and how the road was successfully developed.

Jan 1, 2007

By Amanatidis A

In this paper, the kinetics of iron precipitation as sodium jarosite from aqueous solution is investigated. The determination of the reaction mechanism is attempted based on the experimental data of iron removal as a function of time, without using the characteristics of the precipitate.Experiments at the temperature range from 50° to 95°C were carried out with initial conditions of iron concentration IQ g/L, sodium sulphate concentration 25.44 g/L, sulphuric acid concentration 3.68 g/L, pH = 1.5 and agitation rate 600 rpm. Temperature greatly and positively influences iron precipitation from the solution and this is accompanied by pH decrease. The activation energy was determined using the maximum values of the precipitation rate, which were evaluated by polynomial fitting of the sigmoidal shape experimental curves, and it was found to be 44.37 kcallmole. The determination of the rate-controll ing mechanism was based on some criteria used for the discrimination among the three probable mechanisms of precipitation (diffusion, mononuclear nucleation, polynuclear nucleation). These criteria utilise various funetions of the recovery 'a' of iron precipitated versus time, the most important of which are the chronomals. The results of the kinetic analysis procedure showed that the polynuclear nucleation growth mechanism controls the precipitation of iron as sodium jarosite. This was confirmed by the high value of activation energy, excluding diffusion as the controlling mechanism.

Jan 1, 1993

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

The results of laboratory grindability tests on coal are of primary importance to the designers and operators of coal grinding mills, and coal handling plants in general. However, the potential industrial application of these test results have not been fully realised due to a lack of laboratory-test/field data correlations. This paper focuses on the grindability characteristics of Queensland coals, and provides a new look at an old problem in terms of (i) a more rigorous characterisation of the grindability properties of coal and its associated mineral impurities, and (ii) the correlation of laboratory grindability test results with the size characteristics of run-of-plant thermal coals, and their pulverising characteristics in full-scale mills. A new grindability test is also proposed based on the Yancey, Geer and Price laboratory abrasion-test mill.

Jan 1, 1991

The Indonesian province of Papua is a remote jungle-clad region covering the western half of the mountainous island of New Guinea. Despite being relatively under-explored to this day,Papua is home to the greatest mineral success story of the 20th century. The Grasberg/Ertsberg minerals district atop the central dividing range contains the worldÆs largest reserve of both copper and gold (Freeport-McMoRan Copper and Gold, 2002). With large mines at Ok Tedi,Por gera and Lihir,and many well-delineated resources such as Frieda River,Wafi and Hidden Valley, neighbouring Papua New Guinea,the eastern half of New Guinea has enjoyed sustained exploration campaigns for gold and copper since the mid 1960s. The combined Grasberg and PNG exploration successes can be measured in terms of ounces of gold produced over the last decade versus available landmass,conf irming the island of New Guinea and surrounding islands as a world-class destination for gold explorers. Yet despite this obvious regional prospectivity and the profitability of the Grasberg operation, a sustained exploration effort in the Papua province in Indonesia has not been achieved. Periodic political constraints, poor infrastructure, high costs, operational challenges, social and environmental concerns and lack of immediate exploration success often impact exploration investment decisions. Accordingly a lesser number of mineral occurrences have been documented in Papua compared to those seen along tectonic strike in geologically similar Papua New Guinea.

Jan 1, 2004

By Bloom M. S

Epithermal vein and breccia hosted Au mineralisation at the Kerimenge prospect, in the Wau district, Papua New Guinea, occurs within a block of multiply fractured dacite porphyry of Pliocene age, and is localised on intersecting regional fault structures, marginal to the eroded vent of a Late Pliocene-Pleistocene maar volcano (diatreme).Au mineralisation is primarily controlled by the steeply dipping Kerimenge Fault zone, which hosts a basal zone of silicified breccias,transitional laterally and vertically to networks of fracture controlled veins.Early quartz+pyrite veins, deposited from CO2 rich, NaCl saturated, boiling fluids pre-date the main phase of Au mineralisation. Four stages of Au bearing vein mineralisation have beenrecognised. Quartz+sulphide veins (stage 1) and partially coeval quartz+sulphide+carbonate+ adularia veins (stage 2) occur marginal to silicified breccias, and are associated with quartz+sericite+pyrite wallrock alteration. Similar depositional conditions prevailed for stage 1 and stage 2 mineralisation. Mineralising fluids underwent two stage boiling at temperatures of 145 to 2300 C. Boiling resulted in the loss of approximately 3 wt.% CO to the vapour phase. 2 Fluid salinity was probably I wt.% NaCl or less.

Jan 1, 1990

By L. R. MURPHY

This paper gives a general description of mining operations at the Rosebery Mine and a brief account of the older Hercules Mine. The more unusual aspects of the operations, such as the sinking of the inclined shaft, blast-hole experiments, diamond drilling practice, and proposed future developments are described in detail.The following main heads are used:Roseberry- General production Data.General Description of Ore-body, and Characteristics of Ore and Country Rock.Layout of MineMining Methods, Filling, etc.Blast Hole Stoping.Sinking Main Inclined Shaft.Mining Timber. Contract System.Diamond Drilling and Sampling.Surveying.Labour Force.New Developments, Sand Filling and Pumping.Hercules-Situation of Mine.Transport-Haulage and Aerial.Ore Bodies.Stoping Methods.Ore Handling.

Jan 1, 1949

By Tien J. C

Many factors (type of coal mined, water pump pressure, wetting agent concentration, etc) will affect the performance of a dust suppression system using a water spray in an underground coal mine. While a two-level factorial method is useful in

Jan 1, 1994

Mssissippi Valley-type (MVT) and sedimentary-exhalative (SEDEX) zinc-lead deposits represent about half to three-quarters of the world's production and reserves of lead and zinc. The two deposit-types have traditionally been regarded as separate entities in terms of genesis largely because they possess very different morphologies, resulting from the epigenetic nature of MVT deposits and the syngenetic origin of SEDEX deposits. Similarities in regional setting, metal ratios, size and grade, lead and sulphur isotopes, and source(s) of fluids and metals in the two deposit-types, however, suggest that they could be products of similar genetic processes. The physical properties of MVT ore fluids suggest that certain types of SEDEX deposits could have been formed from fluids possessing similar salinities and temperatures. The hypothesis is further strengthened by the facts that: 1. in several cases MVT and SEDEX mineralisation occurs in the same region, and 2. recent advances in establishing the timing of MVT mineralisation has revealed that some MVT deposits are contemporaneous with nearby SEDEX deposits. If MVT and SEDEX zinc-lead deposits do indeed share a common ultimate derivation from fluids that emanated from sedimentary basins, then the presence of one deposit-type in a region could be used to infer the possible presence of undetected deposits of the other type. Furthermore, knowledge of the mineralisation age of one type will constrain the exploration target host rocks of the other type. A genetic relationship between MVT and SEDEX mineralisation may also explain why certain individual deposits, such as several in Ireland and eastern Canada, appear to be 'hybrids' and possess geological attributes of both end-member types.

Jan 1, 1993

By Smith PE

The main components of face design are the power loader, face conveyor and powered support system and the interaction of these components determines the effectiveness of strata control. A major influence upon the interrelationship of this equipment is the geological environment, of which seam thickness appears to play an important role. Recent thick seam experience indicates a significantly different characteristic behaviour pattern from that observed in thin seams The structural integrity of the face wall is particularly influenced by seam discontinuities such as natural joint planes and mining-induced fractures in the yield zone ahead of the faceline. In addition, the presence of stone bands or dirt partings in the seam offers interfaces for uncontrolled release of blocky material. Some case study experience at British collieries provides a comparison with performance data at a specific location, that highlights the importance of coal face layout and design.

Jan 1, 1986

Geological information plays a significant, cost effective role, in the Mt Whaleback iron ore mining operations. The geology and structure are complex. Good communication between the Mine Planning Production Scheduling and Quality Control Sections is the key to utilisation of geological information to its full potential.Drilling and pit face mapping are the two basic sources of detailed data sets which are processed to prepare up to date geological cross sections and benchwise geological plans. This information is used directly for the blast pattern design and production scheduling. Physical ore type estimation is also undertaken. Orebody models are generated from the geological information.

Jan 1, 1990