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By Dyne GD

From experience in the design and operation of power station combustion facilities in most mainland Australian States, involving a wide range of black coals and lignites, and in the specification and procurement of coal supplies for power station use, techniques for the optimisation of coal resource development and power generation utilisation have been developed to ensure compatibility between characteristics of the selected coals and power station design. These techniques include computer data bases for resource data handling and computer simulation of coal-fired boilers for determining coal property cost effects. Data Base Systems allow results of coal analyses to be efficiently handled, to assist in the review of the relevance of resource data to the coal sections proposed to be mined and the coal fractions proposed to be marketed. Data Base Systems also facilitate the marshalling of coal quality data into basic utilisation format to enable a proper utilisation review and analysis of the certainty and scatter of coal properties. Computer simulation of the effects of different coal properties on the capital and operating cost of power stations is achieved by establishing conceptual design parameters of the major items of plant to relate the variations in coal specification to equipment size and type. Variations in power station budget costs can then be determined using the computer model for variations in coal specification.

Jan 1, 1983

By Swain H. D, Kay R. L

Assessment of mineral reserves in any ore- body hinges on both mineralisation characteris- tics and the economics of extraction. The mineral reserves statement depends on interpre- tation of diamond drill information by geolo- gists, determination of the production plan and operating costs by mining and metallurgical engineers and prediction of future income by economists. The techniques used to generate the mineral reserves statement for Bougainville Copper Limited in 1969 are described and the accuracy of predictions discussed. Preliminary results from a geostatistical reassessment are comp- ared with the ore zone model, blast hole data and concentrator reconciled production results.

Jan 1, 1979

Address by the President (Mr B T Loton) in presenting the Institute medal for 1981 to Charles Wooller Marshall AO. Address by Charles Wooller Marshall AO after accepting the medal.

Jan 1, 1982

By Dunne R. C

Column flotation is receiving increased interest from both an industrial and research perspective in Australia. The traditional overseas application as a molybdenum cleaning cell is being expanded and a number of new applications as cleaners, scavengers and roughers are emerging in Australia. The success of column flotation has hinged on the new understanding developing from the work of Finch- and coworkers at McGill University, Canada, particularly in relation to scale-up parameters and model development. The aspiring column flotation user in Australia now a has wealth of experience to draw on when deciding on the correct procedure to follow during the process evaluation and plant installation stages of development. However, some aspects relating to column design, such as aeration mechanisms, require careful evaluation.

Jan 1, 1987

This paper reviews some of the factors thought to control the formation of supergene gold in the Pacific and its Rim. Discussion of these should lead to reassessment of the economic potential of many areas. In several parts of the world many gold-bearing veins display rich gold values only in the oxidized zone, whereas beneath the present (or ancient) watertable the unaltered vein commonly holds only sub-economic refractory low grade sulphides or arsenides. In the Eastern Highlands of Australia some of the most spectacular concentrations of - gold have been found at shallow depths. For example, Harper (1918) describes the Canton mine in New South Wales which was stoped over a length of 180 metres from the 45 metre level to the surface. The reef yielded gold at 300 g/t in the upper levels, but became gradually poorer at depth. Present geologists of N.S.W. Geol. Survey, G.R. Mcllveen and B.P.J. Stevens, believe that many similar Australian enrichments were formed between the surface and its ancient water table level during the extended period of weathering in the Eocene or pre-Eocene. They concede, however, that further supergene movement of gold may have occurred since the early Tertiary. Large quantities of Mesozoic supergene gold of extreme fineness (Au 99.7%, Cu +òFe 0.3%; Leibius 1885) was found at Mt. Morgan near the Tropic of Capricorn in Queensland. Lower Jurassic sediments cover part of the gossan in a small depression caused by oxidation and collapse of the Main Pipe, thus showing that the supergene gold is pre-Lower Jurassic (Cornelius, 1968). Because the Lower Jurassic landscape around Mt. Morgan was mature with a surface slope of less than 10 (Playford and Cornelius, 1967), erosion would have been very slow. Moreover, once all sulphides had been removed from the ore body the Lower Jurassic environment would have reverted from highly acid to alkaline as it is at present. Accordingly, gold, goethite and 1. Dept. of Geology & Mineralogy, University of Queensland, St. Lucia, Australia,

Jan 1, 1987

By A Xenidis, N Papassiopi, I Paspaliari

Acid generating sulfidic tailings covering a surface area of approximately ten hectares have been deposited in the historic mining area of Lavrion in Greece. For the development of a remediation strategy, the performance of three alternative acid generation control techniques was assessed under actual field conditions. The techniques involved the application of dry covers, including a synthetic HDPE liner and a compacted clay layer with capillary barriers. Furthermore, the potential formation of a low permeability hardpan layer at the sulfidic tailings surface by limestone addition was investigated. The field tests covered an area of 2500 m2, which was divided in equal quadrants, corresponding to the control plot and the three alternative remedial options. To monitor the amount and quality of percolated water, lysimeters were installed beneath the four plot areas. Based on the monitoring results over a period of six years, due to the dry climate encountered in the Lavrion area, a low amount of water percolates through the pyrites if no action is taken (control area), corresponding to 20 - 25 mm per year. This water is highly acidic, pH = 1.2, and contains a heavy load of contaminants, eg Fe 40 g/L, Zn 15 g/L, and As 1.5 g/L. The HDPE cover eliminated the percolation of water into the material for a period of five years, whereas thereafter the volume of leachates increased to values similar to those recorded in the control plot. The water collected in the lysimeter of the clay cover has been minimal corresponding to approximately five per cent of the drainage volume produced in the control area. In the fourth plot, which involved limestone addition to sulfidic tailings, the volume of drainage initially collected was almost double compared to the control area. After three years of monitoring, significant reduction in the amount of percolated water was observed, attributed to the formation of a cemented layer (hardpan), at a depth of 40-80 cm from the testpad surface.

Jan 1, 2003

The Kangiara mine is located within the Middle to Upper Silurian Hawkins Volcanics of the Douro Group near Yass, New South Wales. The deposit is a po1ymetallic type within a rhyolitic tuff.The ore minerals comprise pyrite, sphalerite, botryoidal sphalerite, galena, chalcopyrite, marcasite, tetrahedrite, bismuthinite, bismuth, silver, electrum, chalcocite, covellite, and digenite. The gangue minerals are quartz, barite, calcite, and the host rock. Locally sericite occurs.Several distinct ore types can be recognized, mainly on the basis of their macroscopic textural appearance, and it is inferred from these general features that the mineralization had a submarine volcanic-sedimentary origin similar to that of the Kuroko deposits in Japan.

Jan 1, 1976

By B Ilich, M Brad, R Brandli, E MarT

The Wirtgen surface miner was investigated for application to the Cloud Break iron ore deposit since it can selectively mine thin seams and there is no requirement for drilling and blasting or primary crushing as the surface miner cuts and breaks the rock to secondary cone crusher feed size. A physical metallurgical study of the surface miner run-of-mine (ROM) from Cloud Break was conducted to better understand the product size distribution, amount of -31.5 +6.3 mm lump produced, lump stability and physical metallurgical quality compared to conventional drill and blast techniques. Since the Cloud Break mine was not in production, the lump product from crushing and screening of surface miner ROM was compared with product simulations using traditional premining physical metallurgical processing techniques including drop testing of PQ diamond core. Drop test conditioning is widely used in the iron ore industry to simulate blasting, crushing and screening at the mine and subsequent product degradation during handling from mine to port to predict both the amount of lump product on ship and the size distribution of the fines and lump. The size distributions of surface miner ROM for hard, medium and friable ore types show very tight size distributions with very little above 100 - 150 mm, about 60 per cent of the distribution between 75 and 6.3 mm, with less below 1 mm compared to conventional drill and blast ROM. Crushing, screening and drop test conditioning of the surface miner ROM produced more lump in equivalent ore types compared to drill and blast techniques or their breakage simulation using PQ diamond core. The higher lump yield from the surface miner was also confirmed by pilot scale crushing of some 7400 t of surface miner ROM from the Cloud Break trial pit. The lump produced from surface miner ROM was quite stable and showed similar low degradation characteristics to lump simulated from drill and blasting techniques. Product size distribution simulations using conditioned crushed lump from 1 m diameter Bauer hole samples were found to compare well with processed PQ core samples and surface miner product from trial mining at Cloud Break. The Bauer sample method is therefore considered to be a very useful close simulation to actual lump production, although the lump yield is lower.

Jan 1, 2007

The rapid industrialisation of the world was driven by an improved ability to utilise chemical energy. Unfortunately harnessing explosive energy did not come cheaply given the hundreds of lost lives. However, the modem explosives industry has made significant technological achievements, for explosives are now considered to be both safe and extremely effective. Upon closer inspection, it would appear the key to this achievement has been the development of initiation systems. While the focus may have been originally on safety, modem developments have concentrated upon harnessing the benefits of initiation control. Before attempting to gaze into the future, it is worth reviewing some of the significant advances that have occurred.

Jan 1, 1990

This study begins with the semivario- gram modelling of variables rutile grade and clay content from a beach sand rutile deposit. This is followed by two dimensional block kriging. The deposit was divided into blocks of 30 x 30 x 1.5 m dimensions and the kriged estimate together with the associated kriging variances for each variable within each block were determined. Finally, using the results of the krig- ing program and considering the acceptable limit of clay content together with the cutoff grade for rutile, a method for optimization of mineable thickness and hence the tonnage of ore was applied and the results were dis- Cussed.

Jan 1, 1986

The Split Rock low grade copper prospect was discovered in 1969 by Cyprus Mines Corporation using stream geochemistry. Cyprus "Imes carried out geochemical and geophysical investigations, geological mapping, and percussion and diamond drilling, and concluded that the grade of mineralisation was too low (0.1% copper) to be of interest. In the present study, the geology was remapped and very substantial differences from the previous observations are recorded. (lineraliced acid dykes in a 1 000 foot hole drilled by Cyprus Mines had a total inter- section of almost 300 feet with an average crade of 0.4% copper. Surrounding drill holes at distances of 500 feet did not intersect +hese dykes. This group of drill holes occupies a small part of an area about 2 km by 1 km which was affected by intense quartz sericite pyrite alteration along many fractures with an associated soil copper anomaly. It may be that the quartz sericite alteraiion with feeble copper mineralisation represents hydrothermal alteration emanating `rom a mineralised intrusion of which the dykes mentioned above are off shoots.

Jan 1, 1978

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

By Ooms M, Scott OJ

This paper is concerned with the design and operation of storage and discharge facilit- ies for bulk solids handling. It presents an overview of the basic design philisophy emphas- ising the influence of bulk solid flow propert- ies and bin geometry on the flow patterns developed and how these, in turn, affect the reclaim efficiency and the bin structural in- tegrity and wear characteristics of both bins and chutes. The salient aspects of feeder design and operation will be discussed and the need to consider feeders as integral parts of the bin discharge system will be stressed.

Jan 1, 1978

By Grano S. R, Lauder D. W

Investigations on the oxidation behaviour of chalcocite and its rejuvenation by hydrogen sulphide ion have been undertaken. Chalcocite oxidation was measured using X-ray photoelectron spectroscopy (XPS), zeta-potential and by dissolution in et

Jan 1, 1997

By Gillies A. D S, Just G. D

Coal washability data can be used for assessing coal quality. However, the techniques of using these data to solve quality problems differ from one mine to another and certain problems may never really be investigated due to limitations of the available techniques. One promising way to overcome these limitations is by correct application of geostatistics.A geostatistical study on coal washability data was undertaken based on a data set of closely spaced in-pit bore cores. These bore cores were analysed consistently over a relatively simple geological area. The average distance between the drill holes was about lOOm. There were 78 drill holes available for the area after deleting the erroneous bore cores. During the study, nine extra closely spaced drill holes were drilled within a single mining block.A procedure to construct two coal quality models, a kriging or cokriging model and a simulation model, was proposed. The modelling results for the data above are discussed and results of a mine scheduling exercise based on the models developed are included.

Jan 1, 1992

By Neill A. O, Worth I, O&apos

The formation of Kalgoorlie Consolidated Gold \lincs 1't% Ltd hati pla,xd all the major the gold producing areas adjacent to the city of Kalgoorlie/Boulder under one management, enabling the development of the 'Super Pit'. This has facilitated the economic optimisation of the resource. Optimisation has been achieved by the timely collection and presentation of data and the use of these data to reduce costs and improve planning procedures.In particular the following issues have been addressed:ò the reduction of the impact of the mining activity on the adjacent urban population centre,ò implementation of safety procedures for mining through underground voids,ò the determination of the optimum bench height and mining method for ore production benches and blast design. This system is fundamentally based on maintaining a high degree of selectivity while achieving a balance of relatively low unit operating costs,ò assessment of the comparable benefits of contractor versus owner operated earth moving equipment, andò the development of effective ore body models, production reconciliation and the long term mine planning procedures to facilitate effective strategic planning.

Jan 1, 1993

By Muller M, Ashley PM

Massive sulphide ZnPbCuAg deposits in the Halls Peak district of northeastern NSW are of the submarine volcanogenic type. They occur as a number of small lenses enclosed in shale and epiclastic rocks, in association with felsic volcanics of early Permian age. The deposits crop out in steep terrain near the eastern edge of the New England plateau. Local relief of 700 m and slopes up to 50¦, coupled with an average annual rainfall of about 1000 mm has led to local severe landsliding in previously mined areas. Mining from the 1890's to the 1960's has also resulted in unconstrained drainage of heavy metal-bearing acid waters and physical dispersion of finer grained metalliferous sediments into the Chandler River. Waters emanating from the main landslide area, from underground workings and draining scattered unconfined stockpiles of massive sulphide ore have pH values of 3 to 4 and contain elevated contents of Zn, Cu, Pb, Cd and Fe. Chemical mobility of heavy metals into streams occurs under low pH conditions with Zn exhibiting the greatest dispersion. Increasing pH conditions downstream cause precipitation of Fe phases and coprecipitation of heavy metals. Physical dispersion of secondary metal-bearing minerals into the surrounding creeks results in wt% levels of Cu, Pb and Zn in the stream sediments thereby exceeding the regional background values by one to three orders of magnitude. Areas disturbed by mining are characterised by lack of vegetation, biomagnification of heavy metals into algae and lower plants, and partial recolonisation by metal-tolerant grass species (Snow Grass, Poa sieberana; Blady Grass, Lomandra longifolia). Rehabilitation measures will have to include landslide stabilisation, impervious sealing or removal of sulphidic materials, import of topsoil and revegetation by metal-tolerant, slow-growing native grass and shrub species.

Jan 1, 1995

By Hunter GW

This paper gives an account of the filling system at Mount Isa from surface fill production to stope discharge underground. A brief explanation of the surface facility and reticulation is given prior to the discussion on aspects of underground reticulation. These include fill hole types, pipe and breastplate installation, wear characteristics, etc. The different types of fill and their respective applications is mentioned as a prelude to a general overview of the mining considerations associated with fill placement and its role in the long term planning strategy at Isa Mine. Some practical aspects of stope preparation and filling procedures are outlined for the various stoping methods. Finally a brief outline of future fill developments is given.

Jan 1, 1982

By S Planeta

The use of explosives in underground mining has its drawbacks, particularly in the case of thin or narrow vein type deposits. Due to that, there is a need to develop more discriminative and safe rock-breaking technologies. Mechanical rock splitting seems to be one of the most promising avenues in this respect. This paper describes briefly principles and features of radial-axial splitters. It reviews a feasibility study done to evaluate a potential of this technology in selective mining. It was intended to compare productivity and cost of ædrill-splitÆ mining with conventional cut-and-fill method. Hypotheses and assumptions adopted, methodology used and the obtained results are presented and discussed. The study has confirmed an interesting potential of radial-axial splitters in mining thin and narrow vein deposits. In conclusion, it is stressed however, that it will take more R&D work to corroborate the results obtained. Some suggestions concerning future research in this field are also given.

Jan 1, 2003

While, in the past, a great deal of attention has been focussed on technical issues and the performance of explosives in rock, the explosive user, an essential link in the chain, has often been neglected. In the mining industry, too often, the benefits of excellent technical work have been degraded over time due to the lack of definitive and documented control. Using the principles of quality management a quality training system was developed and implemented for management of explosives use at Gunpowder Copper Ltd (GCL). This paper describes the structure of the system, its development and implementation, and contains practical advice and information for managers responsible for blasting and charge crews. The paper is in four parts: I Quality systems. A brief overview of the relevant aspects of total quality management that apply to explosives use. The requirements for documentation, management and auditing are explored. 2. Training for competency. The five essential elements of Competency Board Training (CBT) are examined, including auditing. 3. The Gunpowder Copper system. Implementation of the complete training system. Documentation and its control, auditing, instructions for operators, management responsibility and means of obtaining operator ownership are amongst the issues raised. Reporting requirements are the means to effectively manage change are described. 4. Summary. The paper concludes with the tangible benefits seen by Gunpowder Copper through the adoption of a quality training System.

Jan 1, 1995