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By Kobayashi M

Particulate chalcopyrite samples (78 ~ 98 mole per cent chalcopyrite, screen size fraction from 710 to 250 µm) were prepared by crushing and sieving lump ore samples from 12 locations in the Mt Isa Mine. Measurements of thennoelectric power (which does not involve the passage of a current) were made using a packed bed that was compressed by loading with a weight and placed in a temperature gradienL Details of the apparatus are described.The effect of particle size was investigated by preparing 12 fractions, with mean particle sizes ranging from 605 to 2.2 µm, from one of the ore samples. Values of thennoelectric power decreased with both increasing particle size and loading pressure; however it remained fairly constant for particle sizes above 80 µm, when loading pressure exceeded 3.3 MPa.Measurements of the chalcopyrite samples gave an average value of -260 JlV/K (-248 ~ -268 µV/K) for nine samples and about -290 µV/K for three samples, showing that these samples were all n-type semi-eonductors.

Jan 1, 1990

By Nguyen V. V

The development of structural defects in the overburden material immediately behind a production blast was studied using surface and subsurface techniques. A significant increase in vertical and horizontal fracture intensity was recorded. The extent of fracturing into the highwall appeared to be dependent on the structural and petrologic characteristics of the various lithological units and the relative position of the explosive charges. A shallow zone of disruption to a depth of 10 m and extending to around 30 m from the newly formed highwall crest was recorded. Horizontal fractures in lower units of the overburden sequence were recorded at distances up to 50 m from the new highwall Face.

Jan 1, 1981

The changing characteristics of raw materials has highlighted the limitations that conventional vibrating screens have in the handling of fine wet sticky materials. These' limitations have led to the development of a totally new concept of screening, the Rotating Probability Screen. In order to illustrate the practical benefits to be gained by the extraction of fine materials ahead of subse quent processes particularly in the coal industry, the experiences gained in Ro-Pro installations in America, Australia, Europe and Britain are drawn upon.

Jan 1, 1984

British Coal has made a practical progressive approach to improving the reliability of its mining equipment. Reliability must be addressed at the specification stage but does not end there and routine procedures are used to procure equipment of adequate reliability. The techniques used to monitor and improve reliability during the operational phase of the equipment, providing engineers and operators with detailed printouts, together with the types of maintenance employed, ensure high levels of availability. Finally, the methods of repair and overhaul of British Coal equipment and systems ensure that the initial reliability targets outlined on the specification, can still be achieved.

Jan 1, 1991

My forebears migrated to South Australia in the 1830s, 1840s and 1850s. All of them were literate but, because they moved about South Australia looking for work, family papers have become scat- tered and I am left with a few fragments. Some years ago I was intrigued to find among my fath- er's books a frontispiece in an old Anglican Book of Lessons. As can be seen Joseph, a mining smith, was also a Freemason. Thus my interest was aroused. I know some- thing of modern day mining communities in South Australia and wondered what they were like 100 or more years ago.

Jan 1, 1987

By Willis I. L, Stevens B. P J, Stroud W. J

The Early Proterozoic metamorphic rocks of the Broken Hill (BH) Block have been recently subdivided into sixteen formations and four groups (Willis et al., 1983b, Stevens et al., 1983). This stratigraphic subdivision has relied upon recognition of distinctive mapped rock units and "associations" of mapped rock units, which characterize particular lithostratigraphic units. The rock units and rock unit associations define local ordered sequences which can be compared and correlated, thereby establishing the stratigraphic succession. In the Clevedale homestead, Thackaringa, BH City, Bores Mine-Freyers mine, Silver King mine, and Brewery Well areas, coherent stratigraphic successions have been interpreted. These areas illustrate the regional variability of the stratigraphic succession and facies changes within individual stratigraphic units. Stratigraphic type sections are located in the Thackaringa, Bores Mine-Freyers mine, Silver King mine, and Brewery Well areas. The principles of stratigraphic interpretation applied in the BH Block can be used in other areas of Willyama Supergroup outcrop such as the Euriowie, Olary and Mount Painter Blocks. The general technique may also have applicability to other highly deformed and metamorphosed terrains.

Jan 1, 1983

Incidental to the progress of a geological survey of the Kalgoorlie goldfield during 1927-28 a number of specimens of telluride minerals were obtained, chiefly with the help of Mr. F. G. Brinsden, general manager of the South Kalgurli mine, and Mr. Ernest Williams, general manager of the Boulder Perseverance mine. This collection was supplemented by a number of small specimens, including the rare copper telluride, which were collected and preseryed from the Kalgurli mine by Mr. A. E. Paton, and also by a few miscellaneous specimens from the collection o{ Mr. S. F. C. Cook, of the Palace Hotel, Kalgoorlie.An extensive knowledge of the rare tellurium-bearing minerals was compiled during the last century from occurrences in Transylvania and Colorado. The recognition of different species has been based on chemical analyses and crystallographic measurements. In a few species there has been an absence of crystalline form, and these, together with the discoveries in this century of rickardite and "weissite" muthmannite and empressite, have depended chiefly on the chemical analysis for identification. On the other hand, the crystalline form of nagyagite and stiitzite has been described in detail, while their precise chemical formulae were doubtfully defined.

Jan 1, 1931

The Loy Yang Overburden System initially consists of a 60 000 tonne/day Bucket Wheel Excavator (BWE) (No. 14), a 2 m wide Conveyor System and a Travelling Stacker (No. TS4). The paper discusses details of the plant and the influence the soft clay overburden has on the design of the plant, to handle the dif- ficult Latrobe Valley overburden.

Jan 1, 1982

This paper introduces a classification of gold orebodies, and comments on the importance of cutting high grade values, the choice of an appropriate ore reserve method and the necessity for producing recoverable ore reserves by considering the mining policy. The author stresses the importance of obtaining the appropriate information from the data relevant to a particular deposit as opposed to transfering parameters from one deposit to another.

Jan 1, 1987

The first continuous pressure disk filter took up industrial-scale operation in Germany in 1976. This paper comments on major components of pressure filter facilities from the point of view of industrial-plant suppliers. For lack of time aspects of economy have not been commented upon. The paper elucidates a number of process-engineering inter-relations. It outlines important development trends from the angle of a machine-building company.

Jan 1, 1989

By Scott SD

The 1986 PACLARK Expedition established that propagation of a seafloor spreading zone into continental crust has created a complex series of volcanic basins on the floor of the Western Woodlark Basin. In addition to abyssal basalts, felsic volcanic rocks were recovered - especially at the leading edge in the extreme west. A recent deposit of hydrothermal Fe-Mn oxides was discovered on an axial seamount of basaltic andesite, and seawater plume anomalies suggest current hydrothermal venting elsewhere. As a modern analogue for the settings in which ancient volcanogenic massive sulfide orebodies probably formed, the Western Woodlark Basin warrants further investigation.

Jan 1, 1987

By Bruce See J

Oxidation of artificial Imperial Smelting Furnace lead bullion was performed during cooling between 1180 and 820°C in order to attempt to produce a tin-rich dross.The addition of sodium carbonate together with stirring increased the tin content of the dross when oxidation was carried out with air or PbO on zinc-free bullion.Zinc in the bullion during oxidation resulted in a decrease in tin concentration of the dross due to zinc oxidation and copper entering the dross.

Jan 1, 1987

The original design of the Bougainville Copper Limited (BCL) concentrator took cognisance of the constraints imposed by the topography, the need to minimise capital cost, and the need to allow for plant expansion which, it was known, would be necessary to maintain copper and gold production as head grades declined.At the same time as spare slots have been taken up with additional equipment, technological innovations have been embraced whenever there appeared to be a chance of improving the productivity ofexisting equipment, or replacing it with a more efficient alternative.There are many examples of this in the BCL concentrator in the areas of process control, process design, instrumentation, materials handling, equipment design and wear part technology.Current process developments also pursue the latest technology. The development of the Omnicone crusher, flotation control, tailings water reclamation, and the variable speed gearless drive on the No. 13 mill are prime examples.

Jan 1, 1986

By Hirose K, Itakura K

A new global stiffness matrix evaluates the performance of powered supports by estimating and comparing the global stiffness matrices of ten different types of powered supports with lemniscate linkages, each support having its own deformation characteristics. Expanding the global stiffness matrix allows the implementation of a finite element scheme to analyse the interaction between the powered support and the strata around the coal face.The evaluation of performance by the stiffness matrix method shows that 4-leg chock shields possess both the desirable convergence and shear deformation stiffness properties. The finite element analysis also confirms that 4-leg chock shields present well balanced performance for controlling strata around the coal face.

Jan 1, 1991

Sublevel open stoping was introduced at Rosebery in 1972; most of the stoping prior to this was horizontal cut and fill. Sublevel open stoping presently accounts for 65% of the Rosebery underground production of 560 000 tonnes per year. This primary stoping technique leaves 50% of the ore in the crown and transverse pillars. The methods used in pillar recovery to date are reviewed and comments made on the success of these operations.

Jan 1, 1982

By Mitchell D. S

BackgroundIn March 1990 Pasminco resolved to replace and increase the capacity of the underground pumping system at the Southern Operations, Broken Hill. The existing pump station was built 23 years ago while the rising main had been in service for 38 years and was subject to frequent failure.The old system was a conventional slurry/clear water separation and multi-stage pumping system. It was inadequate in the following areas:ò insufficient capacity to handle current and expected future flows;ò unable to consistently dewater lower production areas; ò pumping capacity restricted sandfilling rates;ò dirty water dams had insufficient settling capacity and were difficult to de-sludge;ò the operating costs of dewatering were high; ò it was labour intensive; andò it did not offer enough protection to the 25 level loading station.

Jan 1, 1993

In 1874 a stockman, JE Wright of Foxlow Station, recognised copper mineralisation when he was about 12 kilometres south of the station. The find was on the banks of the Molonglo River. Several small mines were soon operating along the ridge above the river, and the village of Captain's Flat was established.One mining company established in the 1880s was Lake George Mines. It's name was to remain synonomous with the name of the town until mining and treatment ceased on 11 March 1962.

Jan 1, 1993

By Kennewell G. J

This paper aims to present the evolution of the mining method in the Prince Lyell orebody. Initial strategy and practical experience are detailed as are the reasons for and benefits of changes to the method since 1972 when underground mining began. This section of the paper starts with ten series and concludes with 40 series which was completed in 1989/90.In addition, to update the series of papers written by various authors over the past ten years on Mount Lyell, a review of the experience in the current 50 series lift of mining will be given. As well, the basic planning guidelines are discussed for 60 series - the final lift of the Prince Lyell orebody.

Jan 1, 1992

Optimum selection of explosives by means of monitoring explosive performance can lead to increased profitability through the control of fragmentation, a reduction in hangingwall and footwall damage and overall drill and blast costs. Studies conducted at the Mount Lyell Mining and Railway Company underground copper mine evaluated in situ the performance of four explosive types. Measurements included monitoring the levels of induced shock energy and the attenuation thereof with distance. The velocity of detonation (VOD) of these explosives was also measured using in-hole techniques. Assessment of these results, together with a knowledge of the rock mass strength, facilitated the selection of an explosive that was best suited to the given rock mass conditions.

Jan 1, 1995

Filter aids are currently used in many industries to increase filtrate clarity and filtration rates. In other industries filtration could be improved if accept- able filter aids could be obtained cheaply. The present paper describes a simple thermal process for making filter aids from coal, outlines the effects of coal properties and major operating variables, and discusses the properties of satisfactory products. Several possible variations in reactor design have been used experimentally, involving fluidized beds of carbon or inert material, reaction of the particles while entrained in air, and a combination of entrainment and fluidization. The limits imposed on product yields by the composition of the parent coal are considered in relation to a range of Australian coals and one New Zealand coal; and the effects of temperature, residence time, and reactant flow rates have been studied in relation to product yields and characteristics.

Jan 1, 1969