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By McGhie R. R

The general structural features and the principal mineral relationships of the Black Star ore body, Mount Isa, Queensland, have been described in several previously published papers. But particular reference may be made to the work of Grondijs and Schouten, whose examination of over 200 polished sections revealed some remarkable features in the process of ore deposition. The observations by the present authors are based upon the study of a smaller ·set of specimens complementary to those examined by Grondijs and Schouten and are intended to elaborate certain aspects of the mineral relationships, more particularly those affecting the ore-dressing processes.The work described applies to the primary sulphide ore only, and to the present milling practice of fine-grinding and selective flotation.GEOLOGICAL FEATURESThe Black Star is one of several economic mineral concentrations in the Mount Isa series of thinly bedded carbonaceous shales, which are considered to be of preCambrian age. The nlineralization is apparently connected with pegmatite intrustions located within some miles of the ore bodies, and has been Gontrolled in the main by major folding of the shales and by a shear system which follows approximately the strike and dip of the beds. The detailed "The investigations described in this paper were made in the Metallurgy Department, University of Melbourne, where the senior author was formerly Senior Lecturer in Mining and Metallurgy. A report on a section of the work was submitted by the junior author as a thesis requIred by the University of Queensland.

Jan 1, 1939

By Hagan T. N

Quite apart from economic considerations, the following performance parameters must be considered when selecting an explosive for a particular blasting operation. 1. total energy yield/kg, and more particularly, strain energy/kg and bubble energy/kg of charge 2. charge weight/m of blasthole 3. sensitivity of the charge 4. water resistance of the charge The effective division of an explosive's total energy into strain energy (SE) and bubble energy (BE) is explained as is the influence of each energy component on blast results. Because some rocks require a high strain energy for effective breakage, while others are most satisfactorily fragmented by bubble energy, values of SE and BE are more meaningful than those of total energy. Unfortunately, our extensive knowledge of the effects of certain variables on total energy has not yet been completely supplanted by the influence of these variables on SE and BE values. Relative SE/kg and BE/kg values are presented for a range of explosives. The 'charge density of ammonium nitrate/ fuel oil (ANFO)-type explosives is essentially constant throughout the length of the charge; because of their compressibility, slurry

Jan 1, 1974

By Wooltorton B

Highwall failures in surface coal mines in Queensland occur as circular slips through weak and weathered material, or as bilinear slides on sub-horizontal surfaces and steeply dipping joints. Weak horizontal planes occur in the Permian-Tertiary unconformity or on bedding surfaces within the Permian Coal Measures. Sub-vertical movements occur along rock joints and tension cracks induced by stress relaxation after excavation. Blasting also introduces new fractures and causes movement along existing rock discontinuities. Critical factors for stability include the dip direction of potential failure surfaces, shear strength of the rocks, damage due to blasting prior to highwall excavation, groundwater conditions, the type and performance of clays on shear surfaces, and pit geometry.

Jan 1, 1981

LITHOPROBE is a national, collaborative research grogram with the general objective of understanding the teotectonic evolution of the North American continent through multidisciplinary lithospheric studies in carefully selected areas of Canada. Six transect areas are investigating Precambrian evolution, although only in two of these is the research well evolved. The Archean Kapuskasing Structural Zone in Ontario is confirmed as an upthrust slice of upper to mid crust exposed at the surface. The Late Proterozoic Keweenawan mid-continent rift is shown to be the deepest known rift on Earth and the Grenville collisional zone of Ontario and Quebec involves crustal scale imbrication and ramping of deeply buried rocks to the surface. Two transect areas are investigating Phanerozoic evolution. In the Newfoundland Appalachians the geologically defined tectonostratigraphic domains do not coincide with lower crustal blocks defined by seismic reflection data. The Southern Cordillera Transect in western Canada is examining the nature, timing and dynamics of the assembly of the Cordillera, and particularly the role of accreted terranes. Work in the eastern and central segments has extended the known western limit of the North American craton at least IOO km westward and crustal-scale ramps associated with metamorphic core complexes have been identified.

Jan 1, 1990

The ore deposits of the Oobar mining field are confined to sediments of the Early Devonian Cobar Supergroup. The mineralisation is discordant to bedding and parallel to cleavage. The structural association is variable with the deposits near the eastern margin of the Cobar Basin formed in zones of deformation and faulting. The Elura deposit located further to the west is in less deformed sediments within the core of a small anticline. There are wide variations in ore type fran lad sulphide chalcopyrite - pyrrhotite - pyrite to high sulphide sphalerite - galena - pyrrhotite - pyrite assemblages. The deposits ccnmonly contain an inner zone of quartz - sulphide - chlorite veining grading outwards into a chlorite halo containing quartz - carbonate veining. The Elura deposit differs in having an inner massive sulphide zone surrounded by a zone of big-Fe carbonate formation. The mineralisation probably formed during regional metamorphism and deformation in the Early Carboniferous. A possible genetic model involves the injection of metal bearing hydrothermal fluids formed in the upper mantle or lower crust up basement structures into the overlying Cobar Supergroup sediments. An alternate model proposes the leaching of metals from the sediments by brines formed during metamorphism and subsequent emplacement in favourable structural zones.

Jan 1, 1983

By Yin J, Sun H

A new technology has been introduced - the use of the High-Water Solidifying Material for providing pumped roadside supports to maintain a roadway for re-use in longwall retreating. As a gob edge support, its initial use at Hebi No. 1 Colliery was successful, providing acceptable performances in support and control of convergences and lateral closures of the gob-edge roadways. This acceptability applied to both first use and re-use when the roadway became a gateroad for the adjoining longwall, remaining stable throughout the associated loadings and convergences. The technology promises economic and social benefits.

Jan 1, 1992

My roots span four generations. My great grandfather, Christian Frederick Fisher, along with twenty-one others was drowned in the New Australasian mine disaster at Creswick in Victoria in 1882. My grandfather, also named Christian Frederick Fisher, escaped and then followed a career of shaft sinking for large companies and operating small mines (very unprofitably according to my father) when funds allowed. My father, an excellent practical mining and mechanical engineer, was also a small miner and my early entry into the industry was, like many before me, very basic. My introductions to the business end of a No. 4 shovel, drilling with hand steel and later with jack hammers without the benefit of airlegs, feeding heavy cordwood to hungry boilers and felling trees for mine timber soon dispelled any illusions I had that mining was a bed of roses.Before it became well known I knew "Life was not meant to be easy".In a family-owned small gold mine in a remote part of Cape York Peninsula in far north Queensland I was fortunate in obtaining an excellent grounding in reef and deep alluvial mining. Operating in vertical and underlie shafts the variable ground conditions often required close timbering. Steam pumps were used underground and steam winders for hoisting.The complete absence of municipal or government infrastructure in this remote mining field threw responsibility on each mine operator to be self-sufficient, and responsible for mine development and installation of crushing and milling equipment, accommodation and water supply. Conditions, although harsh, were acceptable in the 1930s, and fostered great self-reliance.The first crushing from our Black Cat Mine in 1935 returned nearly 200 oz from 10 tons of ore. Gold was then worth $13 an ounce compared to about $400 an ounce today; but in those depression years of the 1930s our operation was profitable.This basic education not only returned dividends when confronted with difficult mining problems, but created a deep respect for the miners who develop the small mines and who continue to contribute to the industry today, often under difficult conditions.Australia and mining are synonymous. The industry has been immortalised by the famous historian, Professor Geoffrey Blainey, in his book "The Rush that Never Ended".Initial gold discoveries were concealed and exploration was frowned upon by authority as being disruptive to early rural development. But with the discovery of gold in the Bathurst area of New South Wales by Hargreaves in 1851, the rush to the gold fields began followed by an influx of migrants. The traumatic effect on industry and society that followed, created the pattern of the love-hate relationship that at times became temporarily submerged, but is so evident today.In the harsh economic climate of the 19th century with low wages and no welfare, the opportunity to wrest riches from the earth was literally "rushed" by the adventurous, the poor, the rich, people from all walks of life. Pressures developed on preFederation Governments to provide law, order and infrastructure to the rushes that have never ended.

Jan 1, 1984

Physical model testing at Bergbauforschung is done in two rigs, a roadway rig and a longwall rig. The loading of such models, in scale relation to the con- ditions in the collieries provides valuable guidance to the probability and nature of failures, and thus to support requirements, in structural, roofbolts and self- auvancing supports. The success of such modelling when related to subsequent underground designs put to use suggests that such methods of investigation could be extended to pillar extraction problems also.

Jan 1, 1974

By Nidagal V

This paper discusses the dewatering strategy adopted and the considerations and procedures required to incorporate a dewaterinq scheme into the Mt Whaleback mining operation. It concludes that in pit pre-dewaterinq has successfully allowed mining to progress below the standing water level with the minimum of disruption or radical change to the mining method. It is recognised however, that dewatering is not a static activity and there is a requirement for ongoing investigations and development. Pre-dewatering commenced in October, 1984. Purpose designed pumping trailers have been employed to minimise the loss of pump availability resulting from the frequent. need to remove and reinstall pumps when close vicinity blasts occur. To July, 1986, some 0.5 Mm' of groundwater had been pumped from the unconfined orebody aquifer. Mining has progressed to some 20 m below the standing water level without. any undue water associated problems. Ultimately, it is ,cheduled to extend some 300 in below the original water level in the West Pit. With the development of an increasing area of the mine below the standing water level, the influence of seasonal high intensity rainfall events, which had previously caused little concern, now need to be addressed. Pumping equipment has been designed to evacuate storm water at a rate consistent with mine production Considerations.

Jan 1, 1986

By Bunting HR

Developments since 1959 in major excavators to meet the high outputs of overburden and coal under the changing nature of the Morwell Coal Deposits of the Latrobe Valley are described. Particular reference is made to investigations of designs of the bucket wheel head configurations for the digging of flat batters on high faces, and examples are given of the wide use ofmodelsin these studies.An explanation is given of considerations leading to selection of the Long Boom or the Compact type of bucket wheel excavator for various applications. The past decade has seen increasing manufacture in Australia of components for excavators and similar machines. The measures undertaken to integrate these components with those from overseas (Germany) are described. A section of the paper deals with advances in Electrical Engineering for large excavators in Australia and its interdependenee with mechanical design and construction. Finally, as an example of the versatility of the bucket wheel excavator a description is given of a recent application for the mining of mineral sands in Northern N.S.W.

Jan 1, 1970

The treatment of the Broken Hill ores has,undergone many changes during the last ten years, and it may be of interest to some of the members to know what are the main lines on which the Proprietary Mine works at present. It must be understood that the want of absolute uniformity in the treatment amongst the various mines at the Barrier does not prove that some of the mines are working on wrong lines, for the ore is not exactly the same along the whole line of lode; this necessitates a variation in treatment, although generally only in detail.At the Proprietary Mine the ore is all mined by contract the miners are paid so much per ton for clean ore. The ore in the mine in most stopes is mixed with gangue, and the inclination of the uliners is, of course, to mix gangue with the ore, so as to be paid for as large 3 tonnage as possible. This is quite natural clean ore is easily distinguishable from clean gangue, but most lumps are a mixture of clean ore and gangue in varying proportions. The miner will naturally throw into his heap pieces which he considers still good enough, whilst the management may consider these pieces just a trifle too poor; consequently a check must be kept on this.This necessitates the first operation to which the ore is submitted. 'The trucks tare 51 cwt.; average load 21 cwt.), as they are loaded underground, have a ticket attached::showing to whiyh contract they belong on arrival at the top of the shaft they are passed over a weigh bridge...

Jan 1, 1907

By Myers PA, Noble MR, Lawrence JS, Cannings WR

The Perseverance orebody presents the Agnew Mine with a wide variety of geological settings, necessitating the application of several mining methods within the limited strike length being extracted.Mining methods have been introduced and modified during the six years' production history of the property and that evolutionary process remains very active.The methods used, in use or planned, are:Hand held scraper cut and fill Hand held mechanical cut and fill Post pillar cut and fillOpen Stoping (uphole benching) Modified vertical crater retreat Sub-level caving

Jan 1, 1985

By Russell F. M

Following the accident in the Peterson section of Mufulira mine in September, 1970, a method had to be found of extracting up to 300 000 tonnes of ore per month from this area without inducing caving. Sandfill mining methods were chosen, necessitating a plant capable of producing both cemented and uncemented fill on a large scale. The paper covers the design and construction of this sandplant which is thought to be unique for its size, as it incorporates three 3 000 tonne capacity settled storage silos, a 500 tonne capacity cement silo, mixing tanks and a control room situated underground. The plant is designed to handle an aver- age of 440 tonnes per hour with a maximum of 660 tonnes per hour for limited periods, delivering either uncemented fill or cemented fill in proportions varying from 1:6 to 1:30. The instrumentation and equipment necessary to give one man operation of the plant is described and the fill mining methods now in use at Mufulira are briefly outlined.

Jan 1, 1973

By Nag D. K

King Island Scheelite is a wholely owned subsidiary of Peko-Wallsend Ltd. The company works two underground mines near the southern end of King Island at the western approach to lass Strait, 240 km south of Melbourne. (See ^igure 1).

Jan 1, 1981

By Bonsall EM, Schwabe MR, Hamlyn DA

Historically, most of the gold produced from Kalgoorlie has been derived from the gold and gold telluride Golden Mile lode systems dominantly hosted within the Golden Mile Doler-ite and to a lesser extent, Paringa Basalt. In more recent times the gold-quartz stockwork ore bodies within Unit 8 of the Golden Mile Dolerite at Mt Charlotte have become increasingly imp-ortant.Extensive low grade gold mineralisation has now been defined to the north and east of Kalgoorlie within rock units of the Golden Mile sequence not generally considered to be highly prospective.Two main types of mineralisation have been defined. The first comprises variably mineralised and altered quartz-albite porphyr-ies emplaced within talc-carbonated Hannans Lake Serpentinite (Mystery deposit). There is intense fuchsitic, pyritic and carbonate alter-ation of the serpentinite adjacent to the porphyry bodies. Gold mineralisation is assoc-iated with fine-grained disseminations and veinlets of pyrite and narrow quartz and quartz-tourmaline veining within the porphyry and adjacent fuchsite-carbonate rock. Several sets of vein directions are present, some of which typically exhibit sulphide alteration haloesnnA H] rhina_

Jan 1, 1984

By Palmer C. G, Rowe P. G

Ore handling improvements at Mount Isa Mines Limited were necessary to keep abreast of technological advances in all phases of sublevel stoping practice.In the early 1930s an efficient ore handling system was in operation.However in 1936 excessive water encountered in deepening the hoisting shaft necessitated the sinking of a second hoisting shaft. Financial difficulties prevented abandoning the original shaft and surface ore handling and crushing facilities, so ore was transferred underground and underground crushing deferred. It was not until 1951 Jhat multilevel crushing permitted increased efficiency in the handling of ore from stopes. Ore was then hoisted in one shaft and transferred on the surface by conveyor belt to a new crushing plant.In 1956 a planned production increase from 5,000 to 11,000 tons per mining day made possible further improvements in ore handling. Larger equipment was installed and existing equipment modified to capacitate the handling of larger sized ore at increased daily tonnages.INTRODUCTIONThe intensive exploratory programme commenced in 1954 disclosed large reserves of both lead and copper ores and in 1956 an expansion programme was initiated to increase production from 5,000 to 11,000 tons per mining day. The increased tonnage would result in decreased costs per ton and further cost reductions would result from increased mechanisation underground. The combined effect would permit larger tonnages of lower grade ores to be included in ore reserves. To achieve both cost reduction and the scheduled production increase, improvement in ore handling was of vital importance.For efficient and low cost sublevel stoping it is necessary to maintain an economic balance between...

Jan 1, 1961

By Cunningham J. C

JUST prior to the war the Broken Hill South Ltd: raised, on the average, 6628 tons of ore per week, all of which was crushed and treated in the 4-section gravity mill and the slime flotation plant, for the recovery of lead concentrate carrying silver. The sandy residues from that treatment were railed to the treatment plant of the Amalgamated Zinc (De Bavay's) Ltd. for the recovery of zinc concentrate by flotation, on the joint account of both companies. Subsequent to that-since 1916-approximately 1000 tons of old dump slime were also treated weekly for the recovery of lead and silver as slime-lead concentrate.PLANT CAPACITYUnder this programme the Babcock and Wilcox boiler plant of 8 boilers was taxed to such an extent as to call for the installation of two additional boilers, each of 2690 sq. ft. of heating surface and 55 sq. ft. chain-grade area.The electric generators and the air compressors of the old powerplant were also loaded to their maximum capacity. In view of the fact that the old power-plant had been added to from time to time since 1901, and that further extension was notpossible, and as it was not, moreover, an economical arrangement, the whole question of power generation was reconsidered. The considerations that determined the installation of entirely new plant were as follows:(1) The need for more compressed air for underground work and more electric current for the extension of the slime-flotation plant for the recovery of zinc, as well as lead, as slime concentrates. Provision of additional power was also deemed advisable for the...

Jan 1, 1921

The approach to this subject is a very general one, but an attempt has been made to cover briefly a very wide field in the nationally important job of manufacturing iron for the iron and steel industry.Some historical data concerning the development of the furnace itself from early days have been followed by the modern ideas on raw materials and their beneficiation. Recent furnace design and modern auxiliaries have been given attention with, finally, some developments in practical operation.HISTORICALWhen dealing with such large 'and costly operating units as blast furnaces, there is not the same opportunity for research in design as in most other metallurgical processes. Over past generations the development of furnace design, or "lines" as it is usually termed, as well as most radical operating changes, has been very gradual.However, there have been some periods of rapid progress due to revolutionary changes. One such was the adoption of the steam engine for blowing and charging operations, and also, during this same era, about 1750, coke was first used as fuel in place of charcoal. Another revolutionary change came some 100 years later, when heating the blast became usual practice.Since then there have been great improvements in mechanical equipment and in the preparation of raw .materials. These factors, together with a better understanding of what happens inside the furnace, have led to the development of those large mechanically operated structures which are the most modern in blast furnace design.For many, years America has led the world in pig iron production and in furnace development, so that American design and practice is now recognised almost as standard. This type of furnace replaced the older stacks in England, Russia, Germany, South Africa and India, as well as here in Australia.

Jan 1, 1947

By Donald D

A number of standard tests are conventionally carried out to characterise strength properties of rock. The values of the parameters obtained are often affected by planes of weakness or defects in rock structure. For the purpose of mine design, the range in values or the class of the strength (obtained from a number of tests) is generally more important than a precise value (obtained from a single or limited number of tests). Research has been conducted to establish a relationship between an indentation index and the strength of the intact rock material from the Eastern Goldfields of Western Australia. The Tamrock Raise Boring Index (RB-i) test, which is quick and easy to perform, was selected as the indentation test. The results show that, for heterogeneous, strong to very strong rock, there is a good correlation between the indentation index and the uniaxial compressive strength and tensile strength.

Jan 1, 1996

An underground storage and filling distribution system is presently being established at North Broken Hill Limited in the No.3 Shaft area. This has been necessitat- ed by the dependence of the present filling system on the No.2 Shaft and its imminent closure due to cessation of production. The storage will consist of three tanks excavated in low grade ore, between the No.20 and No.21 levels, at approximately 2700 feet below the surface. The tanks will each have a capacity of 1500 cu yds. Consideration was given for surface storage, although under- ground storage was thought to have greater merits. Two tanks have been excavated, and are in operation. Three or more outlets are installed beneath each tank, with horizontal connections into the No.21 level 'mixing box'. Water decants from the top of the fill in the tanks, and passes into a decant water sump, at the bottom of which is a borehole to the No.21 level. This is then connected to the mixing box and water used as make-up water with the semiwet solids for transport into the existing pipe distribution system. Preliminary results of the system have been satisfactory and it is envisaged that this system will readily cope with the filling demands of the future.

Jan 1, 1973