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By E J. Hofmann, J E. Hofmann, A J. Hofmann-Fritz

"With its Head Quarters in Perth, global heavy engineering company Hofmann Engineering is one of the largest family owned engineering companies in Australia. The company has pioneered a number of new manufacturing processes and design improvements for components of large comminution equipment.Some of these innovations are: Innovative design improvements of high pressure grinding roll (HPGR) forged steel tyres. Hofmann Engineering has developed unique patented tungsten carbide stud and edge protection designs which improve wear life and introduce quick and cost effective replacement options to further extend the life of the tyre. Development of forged fabricated mill heads using rolled and welded high tensile steel plate as an alternative to cast conical mill heads. Establishment of Australian capability to manufacture and export up to 42 ft. (12.8 m) diameter SAG mill shells. Techniques for fast track, product improved replacements of cracked or damaged mill gears, including in situ profile & wear measurements of girth gears using portable coordinate measuring machine (CMM) technology, forged rim steel and induction hardening technology. Gear and pinion mechanical drive designs to 24 MW or higher for SAG mills of 38 ft. to 42 ft. (11.6 m - 12.8 m) diameter as reliable alternatives to gearless drives.The paper presents case studies from the Australian heavy manufacturing facilities of Hofmann Engineering on large, high powered equipment for both the domestic and export markets.CITATION:Hofmann, E J, Hofmann, J E and Hofmann-Fritz, A J, 2013. Australian innovations in high pressure grinding rolls and large grinding mill manufacture, in Proceedings MetPlant 2013, pp 141-151 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 15, 2013

By C E. J de Ronde

Most of the world's economically significant volcanogenic massive sulphide (VSM) deposits are considered to have formed in submarine arc and backarc settings. While the Kermadec-Tonga arc is an excellent example of an intra-oceanic arc setting, it remains largely unexplored in terms of submarine mineral resources. More than half of this arc (~1400 km of the >2500-km-long feature) lies within the EEZ of New Zealand, where it is defined by at least one sub-aerial and 33 submarine volcanoes. The NZAPLUME (New Zealand American PLUme Mapping Expedition) cruise of March 1999 provided a systematic assessment ofhydrothermal activity on the southernmost 13 submarine volcanoes along the southern Kermadec arc. Using prospecting techniques based on the physical and chemical detection of hydrothermal plumes, we discovered that more than half (7 of 13) of the southern Kermadec volcanoes host one or more active hydrothermal systems at depths ranging between <200 to 1800 m. Chemical results show that the fluids discharged are compositionally diverse among volcanoes and between sites at a single volcano. Plumes over more than half of the volcanoes are gas-rich (He, CO2, H2S) relative to mid-ocean-ridge (MOR) plumes. In addition, most sites are highly enriched in Fe, yielding Fe/Mn values that far exceed those for MORs. One interpretation consistent with these observations is compositional overprinting by addition of magmatic fluids, which are typically highly enriched in gaseous and ionic components. Regardless of the source, it is clear that the ligands (HS-, Cl-) required to efficiently transport base (e.g. Cu, Zn, Pb) and precious (e.g. Au, Ag) metals to the seafloor are abundant in Kermadec arc fluids. We conclude that modem analogs of VMS deposits are likely forming at multiple sites along the Kermadec arc and within the EEZ of New Zealand.

Jan 1, 2000

In 1801, Hatchett discovered the oxide of a new element while he was examining a heavy black mineral from Haddam, America, which had been presented to the British Museum. He named the mineral Columbite and the metal Columbium. A year later a Swedish investigator, Eckeberg, while working with a new mineral resembling columbite-yttrotantalite discovered a new element, to which he gave the name of tantalum.In 1844, Rose announced the existence of two new elements in a sample of columbite from Bodenmais. One was similar to Eckeberg's tantalum and the other was called Niobium. Wollaston, in 1909, attempted to show experimentally that columbium and the tantalum were identical, but it was soon proved that they were two separate elements. Subsequently a number of investigatiors found other "new elements" in tantalum and columbium bearing ores, but these were shown to be mixtures of the twin metals.Since Hatchett's Columbium and Rose's Niobium are identical, it is more fitting to use the name assigned to this element by the earlier investigator. However, the term niobium is still retained in Germany and England.The separation of tantalum and columbium has been one of the major problems for analytical chemists since the discovery of the two elements and it is only in recent years that tantalum of a high degree of purity has been produced. High purity columbium metal is probably still to be obtained.Until 1903 tantalum was merely a laboratory curiosity, but about this time its use in incandescent electric light bulb filaments was discovered. Eight years later it was replaced by tungsten, which was better and cheaper. For a time the electrolytic valve action of tantalum was used in the charging of storage batteries, but the chief uses of the metals' to-day are for corrosion resistant apparatus, in vacuum tubes and as carbides in the manufacture of hard cutting and shaping tools.Most of the recent work on the metals has been done by C. W. Balke, in America. Tantalum has been studied more than columbium. OCCURRENCE OF TANTALUM AND COLUMBIUMI. NATURE OF ORESTantalum and columbium occur, nearly always together, as the oxides in combination with other metallic oxides. The only known exception to this is the reported occurrence of metallic tantalum with gold in the Ural Mountains. Unlike most other metals, no compounds with sulphur are known to occur in nature. Tantalum and columbium minerals occur usually...

Jan 1, 1943

By A Jewbali, J Phillips, C Boyle

Normal practice in the mining industry is the creation of a single geological model. These models provide a single interpretation of the geological and mineralisation domains. These interpretations infer the exact behaviour of ore domain contacts at shorter scales when resource definition drilling is done on wider scales and are thus locally highly uncertain. The interpreted geological model provides a single number for the volume and tonnes of mineralised material enclosed by the mineralisation envelope. It is on this single number for volume and tonnage that capital intensive mine development decisions (mine design and scheduling, stockpile strategy, waste management, closure planning, dewatering strategy, product quality, etc) are based. Some of these decisions require knowledge of grade variability for small volumes of material such as quarterly production periods. It is generally recognised that this information cannot be derived from single kriged geological models, but can potentially be modelled by conditional simulation techniques. Uncertainty in the extent and continuity of the mineralised envelope and its effect on grade variability for shorter production periods is thus recognised as a major source of uncertainty in new mine development.CITATION:Jewbali, A, Boyle, C and Phillips, J, 2013. Quantifying domain uncertainty for an iron ore deposit, in Proceedings Iron Ore 2013 , pp 157-168 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

Ferruginous manganese deposits have been known at Ripon Hills since the late 1950s. The main group of deposits occur in an area 6 km by 5 km and these were extensively investigated by Longreach Metals N.L. during1971 and 1972 for possible commercial exploitation.Ripon Hills is a dissectcd fault plateau 350 m above sea level formed by the uplift of a block of gently dipping Proterozoic shales, cherts, and dolomite. The plateau consists of chert breccia which is underlain by massive dolomite. The shales which are ferruginous and manganiferous overlie the chert breccia but are now only preserved, in places, in the broad depression and valleys of the plateau.The ore deposits occur as supergene replacement of the shales and were investigated by geological mapping, grid percussion and diamond drilling, and bulk beneficiation testing. Iron and manganese oxides erraticallyreplace Shale accompanied by the leaching of other minerals. The ore is composed of fine grained pyrolusite intergrown with fine grained hematite and locally containing extensively altered bixbyite and braunite. Thegangue mineral is mainly kaolin.The average grade, using a 15 per cent Mn cutoff, was 19 4 per cent Mn and 25·9 per cent Fe for a combined drill-proven, indicated, and inferred tonnage of 56,000,000 tonnes. The average depth of this mineralization from the surface is 11 m. Using a cutoff grade of 20 per cent Mn the average grade was 24·6 per cent Mn and 23·0 per cent Fe for a combined tonnage of 12,000,000 tonnes to an average depth of 8 m.The substantial drop in reserves occurs because a high proportion of the mineralized material contains less than 20 per cent Mn.It was shown that whereas the lower grade ore, despite erratic fluctuations in grade, could be beneficiated to specification grade by crushing, screening, and conductivity ore sorting, the higher grade ore could be beneficiatedto specification grade by crushing and screening only. The utilization of the higher grade ore was considered to constitute a more viable operation.There is potential for high grade manganese ore to be discovered in the Ripon Hills area at the contact of chert breccia and underlying dolomite.

Jan 1, 1977

Experimental investigations were made into the decoppering of lead, tin, and bismuth using a technique which approximates on the small scale to industrial practice.Decoppering lead with sulphur alone in the absence of tin and silver did not proceed to low copper values. With a minimum of 0·02 per cent Ag or 0·10 per cent Sn, lead was decoppered to less than 0·01 per cent Cuby stirring with 0·2 per cent S over 10 min. Decoppering of tin or bismuth proceeded rapidly to very low levels in the absence of any "catalytic" impurities, at any rate in excess of those concentrations normally encountered in commercially pure tin or bismuth.

Jan 1, 1971

Mount Isa Mines Limited first installed electronic data processing equipment in 1959. The decision to replace this equipment with a computer was motivated by the need for greater processing power and the availability of new and less expensive computers. Consideration of hardware software and delivery features of available equipment, resulted in the selectIon of an ICT 1900 series computer which was installed in March 1966. Special air-conditioning and power stabilization equipment was also required.Systems design and programming was carried out by personnel recruited from within the Company and trained by the computer manufacturer. Early work was hindered by the problems of remote location.Initial applications were basically accounting functions whIch were taken over from the EDP installation. Subsequently computer applIcatIOns of a more complex technical nature have been undertaken. Future work will include both "scientific" and data processing applications.

Jan 1, 1968

Factual data about the sedimentation in the Newcastle Coal Measures are presented. Data concerning the total coal measure sequence (isopachs, sand/shale ratio, and total coal thickness variation), data about three coal seams (Borehole, Dudley, and Victoria Tunnel) and data about interseam conglomerate units are discussed.From this data conclusions are drawn about the coal measure environment. The western edge of the coal basin, the Lochinvar Dome, although a high feature, was apparently stable during coal measure time. Despite its height it apparently supplied little sediment to the basin.The northern and north-eastern edge, which was unstable, supplied most of the coarse detritus (including the conglomerates) to the basin. The conglomerates show patterns of fluvial origin but after a period of "normal" variations in pattern they become restricted to two parallel zones evidently tectonically controlled. Deposition of conglomerates is episodic and separated by periods of coal formation when deformation was apparently slight. Formation of each of the three seams considered followed a rather similar pattern- each show development of thick coal around the basin edge and poor thin coal in the "axial" region of the present synclinal structure.Evidence of ill situ formation of some areas of the seams is discussed and periodic deformation of the basin during coal measure time is postulated.The unusual character of this coal basin, in particular the very coarse units, is stressed, despite the presence of many "normal "coal basin features.

Jan 1, 1970

By P González, E Córdova, E Faundez

An integrated mine system must be capable of displaying and reporting valuable information that can be used to easily understand, manage and take action on the key parameters being reported.One of the key aspects of integration is the standardisation of the mine information up to a level capable of adapting the main characteristics of past projects at the mine and enforcing the same or higher standards for newer projects being developed.At the El Teniente mine, photogrammetry is used to map the advance of horizontal developments, and the constructed 3D representation of each face is then used by the geologists to obtain structural information about the areas being photographed.The mine realised that valuable mining information could also be extracted from the photogrammetry being applied, with three possible areas of development envisioned.The first area was creating a link between the developments being planned on a yearly and monthly basis and matching them with plan sections of the 3D developments of the system to account for any deviations.The second area was to use vertical sections of the 3D developments to estimate the overbreak of the excavations in different areas of the mine.The third area was the provision of a more detailed analysis of the sections so that they could provide information on the thickness of the shotcrete being applied.This paper presents the different alternatives being used and examines how the project is currently being developed and managed at the mine. It also looks at the challenges associated with implementing the reporting platform and the results being obtained.CITATION:Córdova, E, Benado, D, González, P and Faundez, E, 2016. Mine planning information from photogrammetry sources at the El Teniente Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 653–658 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

This paper describes the behaviour, under creep conditions, of a cast lead creep specimen consisting of five crystals, the boundaries of these crystals being substantially at right angles to the direction' of tension, i.e., across the long axis of the specimen. This particular specimen was obtained in an attempt to produce a single crystal in the manner described in the appendix of a previous paper (1).Thus, the specimen was of the same shape and size, was composed of the same purity lead and received the same preliminary treatment as the single crystal test-pieces.The object of the experiment was mainly to observe the effect of the crystal boundaries on both the deformation of the test piece and the process of recrystallisation and to compare the creep rate of the test-piece with that of a specimen consisting of one crystal only.EXPERIMENTAL METHODThe specimen had an effective test length of 10 cms. and a cross $ection of 0·5 in. x 0·25 in. In Fig. 1 is given a sketch of the specimen to scale showing the positions of the crystal boundaries on all four surfaces. Except for those of crystal No. 4, which was confined to approximately one-half the cross section of the specimen, the boundaries of each crystal traversed the four faces.The specimen was mounted in exactly the same manner as the single crystal specimens. During the creep test, it...

Jan 1, 1941

The major copper orebody at Mount Isa is being extracted at a rate of four million tonnes per year. The method used requires an equivalent rate of back filling with (mainly) cemented fill. There were three major incentives for developing this mining system. The first was the prospect of high ultimate recovery of the orebody. The target is 100 per cent recovery. Also the proposed stoping layout appeared to offer significant advantages in development and production costs. Finally, extensive subsidence above the northern end of the orebody could have disturbed permanent surface installations and jeopardised a possible future open cut. The full implications of this ambitious strategy were not apparent in the early years. Now, after 12 years of production the benefits are being realised and they can be weighed against the costs. Probably the most interesting result which comes from this analysis is the significance of cutoff grades and dilution factors in balancing mining and filling rates.

Jan 1, 1980

Early strategic mine planning includes decisions over the organisation of work and workforce accommodation. These decisions involve significant commitments that affect not only employee quality of life but also the impacts and relationships with existing local communities. Strategies for workforce accommodation are characteristically community-based (either as purpose-built company towns or integrated within existing local communities) or commuter (fly-in, fly-out) mine camps. The quality of accommodation underpins the fulfilment, morale and motivation of employees. This is not only relevant to productivity and safety, but also to recruitment and retention, particularly with the current onset of a significant human resources crisis. In the event that communities exist in proximity to a proposed mine then the accommodation strategy selected can influence the value-adding potential for the sustainable development of such communities. This early planning is particularly challenging where mine locations are isolated and/or face significant economic, social and political adversity. This paper draws upon a case study review of five large mining projects implemented in three South American countries, selected to cover a range of scenarios and accommodation strategies. The review aims to advance our understanding of the complexity of the underlying planning issues. Each scenario considered the prevailing environmental, social, economic and political situation, together with the adopted accommodation strategy. The case study review aimed to identify lessons learned and to make recommendations for advancing mineworkersÆ accommodation planning practice.

Jan 1, 2006

By X-F Zhao, J-W Li, L-P Zeng

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The formation of Kiruna-type deposits has been ascribed to either immiscible iron phosphate melt separated from silicic magma or precipitation from magmatic-hydrothermal fluids. The early Cretaceous Ningwu volcanic basin in Eastern China contains tens of Kiruna-type iron deposits. The orebodies are mainly hosted within the top zones of subvolcanic dioritic intrusions and along the contacts between these intrusions and adjacent volcanic rocks/strata.The orebodies are commonly associated with widespread brecciation and wall rock replacement. Magnetite formation was closely associated with extensive hydrothermal alteration that may extend kilometres, with both vertical and horizontal zonation. Field and textural data indicate that magnetite formed slightly later than albitisation but coeval with apatite and actinolite. Elemental analysis of magnetite and apatite from ores shows distinct features to those as igneous accessary minerals in the host dioritic intrusions, suggesting a genetic relationship to magmatic-hydrothermal processes. Magnetites have elevated TiO2 (up to 5 wt per cent) and V2O3 (up to 0.7 wt per cent), which implies that they are derived from incipient high-temperature magmatic fluids. It is concluded that the Kiruna-type deposits in the Ningwu basin most likely formed from high-temperature magmatic-hydrothermal fluids. The emplacement of dioritic intrusions into a subvolcanic setting likely plays a critical role in the development of Kiruna-type deposits.CITATION:Zhao, X-F, Zeng, L-P and Li, J-W, 2015. Kiruna-type iron deposits in the Mesozoic Ningwu volcanic basin, Eastern China – origin and relationship to subvolcanic dioritic intrusions, in Proceedings PACRIM 2015 Congress, pp 657–662 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Belcher C. B

A procedure was required for the rapid determination of silicon in low-alloy irons and a suitable method used the formation and reduction of silicomolybdic acid at 50°C. The procedure gives results for elemental silicon and this enables the correct computation of oxidation requirements in basic oxygen steelmaking. The method could be useful in iron foundries which have not installed direct reading spectrometers.INTRODUCTIONOxygen steelmaking experiments required rapid determinations of 0,5-1,6 per cent silicon in iron (3-4 per cent C) within 10 min of sampling; a reproducibility better than ±0.03 per cent Si was desired. Only elemental silicon (Si°) is of interest as a fuel in basic oxygen steelmaking technology, and the proposed procedure determines exclusively this form of silicon. The method is described as it may prove useful to other workers although the interference study would be incomplete for some applications.The analysis of silicon in iron is frequently obtained using direct reading spectrometers, but for the proposed experiments the spectrometers could not be used because of the prohibitive distance from the furnace. It should be noted that spectrometers determine both the elemental silicon and that present as silicon dioxide in occluded slag and inclusions.The silicon content of iron and steel is determined in this laboratory by spectrophotometric measurement of a "molybdenum blue" colour. The reactions involved have been extensively investigated; Strickland (1952) showed that a...

Jan 1, 1965

By W Taylor, S Chen, R Haywood, M White, R West, J Ranasinghe

In March 2012 a combined BHP Billiton and Hatch team embarked on a program to improve the concentrate burner efficiency of BHP Billiton’s Olympic Dam copper flash smelting furnace. A multi-faceted approach including an analysis of the furnace using operational knowledge and first principles engineering led to the design and supply of a new central-lance (disperser). A new, patented, swirl method of introducing the copper concentrate into the furnace was developed to integrate with the existing concentrate burner. Plant trials in 2014 demonstrated an increase of nearly 10 percent in the oxygen efficiency of the furnace. The improved efficiency is expected to provide savings in operating costs and asset life extension of downstream gas and dust handling equipment.CITATION:White, M, Haywood, R, Taylor, W, Chen, S, Ranasinghe, J and West, R, 2015. Improved copper flash smelting at Olympic Dam, in Proceedings MetPlant 2015, pp 382–395 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

A BRIEF DESCRIPTION OF TELPHER HANDLING AND BLAST FURNACE EQUIPMENT.The various sections will be described in the following order:(a) Telpher Handling and Storage Bins.(b) Blast Furnaces.(c) Slag Disposal.(d) Bullion Handling to Drossing Kettles.(e) Copper Drossing.(f) Copper Matte Furnace.(g) Bullion Delivery to Refinery.(h) Fume Handling.(a) TELPHER HANDLING.The telpher installation is an all-steel structure designed to carry out the work of assembly and delivery of charge materials to the blast furnaces.To simplify description, the primary telpher installation will be divided into three (3) sections:-No. 1 Section. 395 ft. long, running north and south, parallel to the water front, and so located that coke, which...

Jan 1, 1937

The results of self potential geophysical surveys conducted over base metal prospects near Orange, Goulburn, and Wellington, N.S.W., indicate that this rapid and inexpensive exploration procedure merits wider application within eastern New South Wales, and in similar environments elsewhere.

Jan 1, 1973

In 1961, West Australian Petroleum's Eneabba No. 1 bore encountered 22 seams of coal totalling 40 ft in thickness between the depths of 6373 ft and 6441 ft. On analysis, this coal had a similar calorific value (8000-HOOO B.T.U./lb, assuming 20 per cent water) to the coal from the Collie Coalfield, Western Australia's only known area of commercially exploitable coal. Being buried to depths in excess of 6000 ft, the coal at Eneabba had developed weakly-coking properties, and thus, although much younger than the Permian coals of Collie, gave promise of being a major potential source of power for Western Australia.West Australian Petroleum undertook a programme of stratigraphic drilling and shallow test drilling to determine whether this coalhorizon persisted into the outcrop of the Lower Jurassic sediments in the Hill River district, 140 miles NNW. of Perth, and, if it was present, if the quality and quantity of the coal would warrant development of the deposits by open cutting. The coal horizon was identified in the near surface, but the poor quality of the coal and the complexity of the structure made development (in the area examined) uneconomic at the time.A strong seismic reflection in the Eneabba area occurs at the same depth as the Jurassic coals. This event originates within the upper beds of the Lower Jurassic and it is probable that the velocity contrast between the higher velocity siltstones and the very low velocity coals enhances this very strong, distinctive seismic reflection.This event can be followed on continuous seismic data over a large area of the northern Perth Basin, from 13 miles SE. of Dongara to 20 miles SW. of Coorow. It can be followed from a depth of 4000 ftnear Dongara to over 17,000 ft to the SE., so development of thisvast potential source of power will depend on the economics ofprocesses being developed for the production of power from theburning of coal seams in situ.INTRODUCTIONThe discovery of 22 seams of economically useable coaltotalling 40 ft in thickness in the Lower J urassic sedimentsof the Eneabba No. 1 bore (Fig. 1) led to the search forthese seams at economically workable depths. The Ministerfor Mines in Western Australia granted to West Australian1. Supervising Geologist, West Australian Petroleum Pty. Ltd.Manuscript received at The Institute, 25th May, 1964. and presented to the 1964Annual Conference.

Jan 1, 1964

By S L. Garwin

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Since the Eocene, New Guinea tectonics have been driven largely by the south-westerly-directed collision of accreted arc terranes with the northern margin of the Australian Craton, and subsequent westerly-directed transport of these exotic terranes by left-lateral strike-slip fault systems. The subduction of the Solomon Sea plate beneath north-eastern New Guinea in the mid- to late-Miocene led to magmatism and related gold-copper porphyry and epithermal mineralisation in the Maramuni arc and the formation of the Frieda River, Nena, Wafi-Golpu and other deposits.The development of the world-class porphyry and epithermal deposits in the Medial New Guinea magmatic belt, including Grasberg, Ok Tedi and Porgera, is localised by dilational zones formed about the intersections of north-easterly-trending, reactivated basement faults and north-dipping reverse faults related to the southward progression of the Papuan fold belt during the Late Miocene to Pleistocene. These deposits probably formed during short mantle-derived magmatic episodes in zones of regional isostatic uplift, which are attributed to the delamination of the lithospheric mantle beneath New Guinea.CITATION:Garwin, S L, 2015. The tectonics, geology and gold-copper metallogeny of New Guinea, in Proceedings PACRIM 2015 Congress, pp 151–164 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

THE present article makes no claim to be exhaustive, since it cannot contain all the knowledge which scientists and manufacturers of the compounds of the rare earths have gained. The following notes are, therefore, simply an attempt to ascertain andclearly record the occurrence, properties, and uses of the more important of the rare earths, with a special reference to their commercial values and the industries based upon them.HISTORYIt was the mine manager, Gcyer, of Stockholm, who, in 1788, first drew attention to a black mineral which had been found in a quarry near Roslagen, in Sweden. In 1805 Klapproth received some specimens of this mineral, which he declared to be a newmineral. Subsequently Gadolin, professor of chemistry at Abo, analyzed the same mineral, and determined the presence of an unknown earth resembling alumina and lime. He named the mineral ytterbite, and afterwards gadolinite. Klapproth has alsothe merit of having detected (1804) another rare earth, which he named ochroit-earth, found in the Bastnas mine, near Riddarhyttan, in Wcstmannland, Sweden. Curiously enough, Hisinger and Berzelius simultaneously ascertained the existence of the same...

Jan 1, 1909