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By Wilson R. G

The Bulli and Wongawilli Seams, the two principal sources of coking coal for the Port KKembla steelworks of Australian Iron and Steel Pty. Ltd., vary in rank and in type over the Southern and -South Western Coalfields. The Bulli Seam, ranging widely in type, produces coke varying from weak to strong. The Wongawilli Seam, more consistent in type, produces coke of more consistent strength, but considerably less strong than that from the best Bulli Seam coal. Plans of seam variation show the regional trends in rank and type for each sear. The strongest coke is derived from coal containing between 45 and 55 per cent vitrinite, m.m.f. This is obtainable from the Bulli Sean in a zone embracing Bulli and Appin Colleries.

Jan 1, 1969

The Century zinc-lead-silver deposit has a geological resource of 118 million tonnes averaging 10.2% zinc, 1.5% lead and 36 g/t silver. It lies approximately 250 km NNW of Mt Isa in NW Queensland, Australia, and is hosted by middle Proterozoic age siltstones and shales of the Lawn Hill Formation. Within the orebody, most mineralisation occurs selectively within black shale units as fine grained sphalerite and galena lamellae with minor pyrite and siderite. The black shale units are separated by weakly mineralised sideritic siltstone horizons. The deposit is unmetamorphosed and only weakly deformed, displaying excellent lateral stratigraphic and grade continuity.

Jan 1, 1995

Drill and blast excavation in underground mining and. civil engineering projects has grad- ually given ground to mechanical boring of tun- nels, shafts and raises during the past twenty years. The use of.boring equipment must today be considered significant and wide spread al- though comprising only a very small percent of total underground excavation. The encroachment of mechanical boring into the domain of blast- ing has been by slow incremental advances. There have been few, if any major breakthroughs in this development, and none can be foreseen in the next decade. After 1990 it is possible that scientific. development will provide some form of breakthrough in rock breaking, but this is so uncertain that it should have little relevance to planners in the 1980's. A more near term view of the future, con- centrating on the next five to ten years, has lead to the conclusion that significant im- provements will be seen in tunnel borers for poor ground conditions. A universal machine will be developed that converts from a dry hard rock machine to a closed slurry type machine for passing through fault zones with unstable crushed rock and water. Two other machines have been described as alternate designs for tunnelling in squeez- ing ground conditions.

Jan 1, 1981

A co-operative research project, combining Commonwealth Scientific and Industrial Research Organisation (CSIRO) research scientists findings and company iron ore geologists' expertise, resulted in new concepts about the origins, distribution and complexitie of iron ores and their parent rocks (banded iron-formation or BIF) in the Hamersley Iron Province of Western Australia. Understanding these problems was important to the efficiency of exploration, development and ultimate mining of iron ores. This genetic model, based on a detailed mineralogic background, was modified by Mt Newman geologists to obtain a user oriented classification for practical application in the field.The proposed Pilbara Iron Ore Classification (PIOC) gives iron ore geologists a basis from which to understand, identify and record the various mineralogic and physical characteristics of the many genetically different ore types occurring within and between orebodies in the Pilbara. More definitive quality control over ore products can be achieved based on the detailed understanding of ore types which the PIOC allows, compared to current classifications which deal only with the physical nature of ores. Of equal importance, the classification remains sufficiently simple to enable owners, operators and buyers to achieve a basic appreciation of ore type variations.With little modification, it is believed the classification has applications beyond the Pilbara, to iron ore worldwide.

Jan 1, 1984

By Leung L, Downey M

This paper presents an overview of a technology package developed by BHP for locating discontinuities in coal seams using an in-seam seismic (ISS) exploration technique. The technology package includes instrumentation, data processing software, field procedures, numerical modelling and interpretation know-how. The technology developed has proved to be highly successful; features such as faults and dykes, not detected by other methods, have been delineated. Using equipment specifically designed for underground use, surveys are carried out quickly and at low cost. More than 30 ISS surveys have been conducted by BHP in Australia. Substantial savings in production revenue have been realised in situations where ISS has identified mining conditions which would have impeded longwall operations. Case studies of several ISS surveys are described in the Paper.

Jan 1, 1987

By Braaksma M, Dudley K

The Girilambone Copper Mine is located in central New South Wales and has been operational since May 1993. Girilambone is operated by the Girilambone Copper Company (GCC) which is a joint venture between Straits Resources (60 per cent) and Nord Resources (40 per cent). The mine complex consists of an open cut pit, ore crushing and stacking, heap leaching, solvent extraction (SX) and electrowinning (EW) allowing for the recovery of 14 600 tpa of LME grade A cathode copper. The leaching and SX-EW plant have been described previously by Rear, Taylor and Busby (1994) and Miller (1994).

Jan 1, 1996

By Denby B, Hollands R. Schofield D

Surface mines are in operation worldwide, the vast majority employ large haul trucks for the transfer of material both to the outside world and around the site. The sheer size of these trucks and the operating conditions means there is a high

Jan 1, 1998

By Bedford D. J

The post pillar cut and fill stoping method has been adopted by King Island Scheelite for the extraction of the main Dolphin orebody. The orebody is a massive, tabular deposit varying from 10 to 50 metres in thickness, and dipping at approximately 30¦ towards and under the sea bed. The mining method was selected for 1. maintenance of hangingwall support under the sea bed; 2. maximisation of first stage ore extraction; 3. flexibility of mining, allowing maintenance of grade and selective mining around waste bands within the orebody, and 4. compatibility of existing equipment both with stoping and the on-going underground mine development programme. Stope parameters were established on the basis of initial rock stress analyses, and since the undercut phase of mining the stoping programme has been monitored with various types of deformation measuring devices installed in a series of large diameter boreholes.

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

In a country richly endowed in mineral wealth, Climax Arintco Mining Corporation's ICAMC) Dinkidi porphyry Au-Cu deposit in Nueva Vizcaya, Philippines, represents the most significant mineral discovery in this country in recent times. The deposit is located within a belt of young intrusive and volcanic rocks in the Sierra Madre mountain chain of north Luzon, a region previously unassociated with porphyry -style mineralisation.Since 1989, drilling of the Dinkidi deposit has outlined a resource of 124 million tonnes of 1.0 g/t gold and 0.4 per cent copper. Regional exploration throughout CAMC's 37 000 hectare FTAA has identified a further 16 potential porphyry-related deposits.

Jan 1, 1997

By Will D

This presentation is to outline the current practice of mechanised stoping a one-metre wide, gold bearing ore body to optimise fragmentation, minimise dilution and reduce stoping costs.Coolgardie underground operations have historically been mined using traditional shrink stope methods, but in this recent economic environment (with falling gold prices and high costs of traditional methods) it was necessary to look for alternative methods in order to reduce costs and increase productivity.Although still in a learning and refinement phase, CGNL is satisfied that it is feasible, practical and more economic to use mechanised long up-hole stope and long-hole rising methods to significantly reduce the mining cost, reduce dilution, increase safety and increase productivity three-fold compared to traditional airleg methods used throughout the Fasten Goldfields.

Jan 1, 1993

By Sowerby BD

The CSIRU Division of Mineral Engineering is developing various techniques for the on-line determination of moisture in coal and coke, and some instruments are now commercially available. These techniques permit accurate and rapid determination of moisture in materials directly on conveyor belts or in bins. The most promising techniques for direct on-belt measurement of moisture in coal are capacitance and microwave transmission. A non-contacting under-belt capacitance and gamma-ray backscatter technique has determined moisture in coal to better than 0.5 wt'/. in field tests at BHP Stockton Borehole Colliery, NSW. Mineral Control Instrumentation Pty Ltd have been licensed to manufacture the capacitance gauges and have installed five commercial units in the coal industry and other industries. Microwave transmission techniques have an advantage over the under-belt capacitance technique in that they are not sensitive to vertical segregation of moisture in coal on the conveyor belt. A laboratory prototype of a microwave transmission gauge has been constructed and tested. Microwave techniques, based on a measurement of attenuation and phase shift, are under development and are expected to be field tested in 1987. These new techniques will enable a wide range of thickness changes to be accommodated. Capacitance and microwave transmission methods are unsuitable for materials of high electrical conductivity, such as coke. CSIRO is therefore developing a fast neutron and gamma-ray transmission technique, which is proving very accurate in laboratory tests. This technique overcomes many of the limitations of thermal neutron moisture gauges and it is expected to be field tested in 1987.

Jan 1, 1987

By Potter DJ, Firkin GR

The Imperial Smelting Furnace operated by Sulphide Corporation Pty. Limited at its Cockle Creek zinc-lead smelter was recently equipped with tuyeres angled at 25 degrees instead of the usual 10 degrees. This change was prompted by the results of model studies undertaken by tha Research Department of Imperial Smelting Processes Limited, at Avonmouth in the United Kingdom, and by the favourable results of operating trials on the Cockle Creek furnace using bent-tip tuyeres to simulate 25 degree inclination. The use of 25 degree angle tuyeres has made it possible to operate with lower zinc values in discard slag and has improved hearth stability over a wider range of sinter quality and composition.

Jan 1, 1981

By Edwards A. B

Re-opening of the old Proprietary mine has provided new exposures of the system of uralite dolerite dykes observed in 19110 by the Geological Sub-Committee of the Scientific Society of Broken Hill. The newly exposed dykes have been invaded and replaced by the massive ore, with development of manganese garnet and biotite adjacent to the sulphides. A similarly altered dyke in massive ore has been encountered in the North Broken Hill mine.The textures of the unaltered portions of these dykes indicate that they have not been affected by the intense regional metamorphism that has recrystallized the other rocks of the area. Moreover, in mineral composition and textures, in chemical composition, and in cross-cutting relations, they are so similar to the uralite dolerites of the district which post-date the folding and metamorphism of the Broken Hill area, that they must be regarded as typical members of this suite of post-metamorphic dykes.The invasion and replacement of the dykes by the massive sulphide ore, and their metasomatic alteration adjacent to the invading sulphides, establishes that the lode was formed after the dykes were intruded, so that the high temperature features of the ore cannot be attributed to metamorphism and recrystallization, but are primary features of high temperature hydrothermal deposition.INTRODUCTIONTwo cross dykes are recorded on the plan of the 300-ft. level of the Broken Hill lode accompanying the report on the geology of the Broken Hill lode published by the Geological Sub-Committee of the former Scientific Society of Broken Hill (1910). One dyke occurs in Block 12, and the other in Block 13, and both were stated to consist of a dark basic amphibole rock, called diorite for convenience. The more southerly dyke was traced from some distance out in the footwall, and even through the lode, by means of occasionalpatches of it still existing in the ore, in a direction...

Jan 1, 1956

In the process of mining the lower seam in a multi-seam operation, a lot of oblique fract- ures appeared in the upper seam which was in the equilibrium zone. These fractures closed soon after the lower face line passed. Despite the occurrance of some degree of undulations, and and step-like unevenness, the upper seam was subsequently extracted without difficulty. When attempting multi-seam extraction, from the height of the equilibrium zone, the minimum distance between seams in ascending mining should be predicted. By analysing roof con- vergences data and the geometrical configuration of subsidence profile, it was found that the minimum safe distance for ascending multi-seam mining depends on the mining height of the lower seam and the properties and structure of the inter-stratified rocks.

Jan 1, 1986

By Spottiswood DJ, Kelly EG, Bull WR

An empirical model of a 254mm water-only cyclone treating minus 17001im coal has been developed. The model includes the prediction of by-passing, SG50 corrected, water split and the use of a single equation forthe reduced performance curve of particles in the range 1700-106pm. Particles finer than 106pm did not separate according to specific gravity. Simulations using the model showed the water-only cyclone performance to be dependent more upon feed size distribution than washability when the feed contains high-ash fines, but that, with a deslimed feed, the yield and ash content of the over-flow should be controllable by altering feed rate or feed pulp density.

Jan 1, 1985

Au airway hteat and moisture exchange .,Jgorithm is described which is generalised to suit most mining situations and can be run separately on a microcomputer or used within a network simulation. The main difference between this technique and other simplified methods is that a non-uniform boundary condition is allowed for. This permits radiative heat transfer between surfaces of different wetness in addition to evaporative and convective heat and mass transfer.

Jan 1, 1988

By A Black, J H. Youngson

At least 85 000 tonnes of mine tailings were discharged into Deepdell Creek, east Otago between 1890s and 1940s. The tailings contained about 1 wt % arsenic, so about 850 tonnes of arsenic in the form of arsenopyrite was discharged. Annual floods have removed nearly all tailings within c. 60 years. Small amounts of arsenic-bearing sediments (<250 ppm) remain in Deepdell Creek. About 7 kg/year dissolved arsenic was discharged in groundwater from mineralised Hyde-Macraes Shear Zone rocks in the vicinity of the historic mine sites. Adsorption of this arsenic on to iron oxyhydroxides in the stream sediments may have contributed to the elevated As content of those sediments. Even less arsenic remains in the main Shag valley below the Deepdell Creek confluence (15 - 25 ppm As). Rare relict arsenopyrite grains are trapped in bedrock crevices 25 km from source. No tailings deposition is detectable in theShag River estuary, and the tailings have presumably been discharged into the sea. Natural rehabilitation of the Shag catchment has been rapid and effective.

Jan 1, 2004

By P Carrasco, E Me, M Campos, J Tapia

Correct sampling practices are of vital importance to the mining industry; key decisions for the business are made on the basis of samples in all the value chain. Geology plays a relevant role in pre- and post-investment stages. Actually the understanding of natural variability is essential for geological modelling, geometallurgical modelling, mine planning, grade and process control. Improper sampling practices obstruct this objective introducing irrelevant variability components, which can cause monumental economic losses. A good approach to accomplish this understanding is the application of heterogeneity and IngamellsÆs tests, which are useful tools to quantify the variability of a certain well-delimited geological unit at different comminution scales. The application of heterogeneity test can help minimise Pierre GyÆs fundamental sampling error and to study the impact of other sampling errors. IngamellÆs test allows us to define the correct mass of sample for chemical analysis. This paper presents the results of several heterogeneity and IngamellsÆs tests done in Chilean porphyry copper deposits that belong to CODELCO Chile (Chuquicamata, Mina Sur, Radomiro Tomic, El Salvador, Andina and Teniente), in different geological units (endogenous oxides, exotic oxides, supergene sulfides and hypogene sulfides) and for several elements (Cut, Cus, Mo and As). These tests, considering the natural variability, have helped us develop accurate sampling protocols to minimise the fundamental error to acceptable levels. A major contribution of these tests (more than 30) is the generation of secure sampling protocols using the highest sampling constant obtained in the tests, for new porphyry copper deposits that donÆt have information given by heterogeneity and IngamellsÆs tests.

Jan 1, 2005

By Mortimer RR

The Weipa bauxite mining operation on the west coast of Cape York currently mines lb million tonnes of crude ore per year from the Andoom and Weipa mines. Andoom ore is trucked up to 4 km to a rail load station and hauled 20 km by train to the Beneficiation Plant. Weipa ore is trucked up to 7 km to the Beneficiation Plant. Increasing haul lengths and production requirements have led to a progression of larger two axle rear dump trucks and currently he intrcducticn of 145-tonne, three axle L t Dm dump trucks. bith the introduction of the Andoom a operation in 1972, the decision was made to use a railway system to haul crude ore from Andoom to Weipa. This system has proved to be successful from both an economical and operational view point. Due to the successful combination of a truck and rail haulage operation in Andoom, future :evelopment of orebodies requiring increased haul distances and increased production tonnages will probably result in extension r>f the railway system to compliment the trucking operation from the mine face.

Jan 1, 1978