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By P Fullagar

Automated multi-sensor core loggers (MSCL) measure petrophysical properties of diamond drill cores, including gamma density, P-wave velocity, electrical conductivity and magnetic susceptibility. A Geotek MSCL system has been used to record petrophysical data on archival drill core from Cadia East Au-Cu porphyry deposit, New South Wales, Australia, for correlation with metallurgical parameters. P-wave modulus, calculated from density and P-wave velocity, exhibits a correlation with small-scale crushability (A*b) test results, and hence offers a means for æcontinuousÆ characterisation of ore crushability at Cadia East. Magnetic susceptibility has proved to be a good indicator of alteration styles, and is a possible indicator of crushability.

Jan 1, 2009

By Fookes R. A, Gardner K. J, Gravitis V. L, Watt J. S, Steffner E. J

Two radioisotope techniques suitable for the rapid laboratory determination of the ash content of coal have been tested ou unwashed coal samples from four Australian coal seams. In one techniqne, measurements of backscattered 238Pu L X-rays and iron K X-rays from finely ground coal samples have been combined to determine ash content in uuwashed coals to ±0.5 weight per ce111 ash (ls) for three seams and 0.9 weight per cent ash for the fourth.The second technique, which involves measurements of the transmission by the coal of narrow beams of 241Am 60 keV and 123Ba 356 keV ? rays, requires less sample preparat ion. The ash was determined to within the range of 0.8 to 2.6 weight per cent for the four seams (unwashed coal). For washed coals, errors are expected to be < ±0.5 weight per cent ash.

Jan 1, 1982

Drilling and blasting are an essential part of most mining operations, and are commonly major operating cost centres. The effectiveness of blasting can have a significant influence on all subsequent activities, and hence overall operating costs. Drilling and blasting systems must be compatible with the overall mining method, to minimise total costs and ensure operational efficiency. Selection of suitable equipment and techniques requires an understanding of the total operation, plus current skills in specialised technologies. This paper examines the contribution of drilling and blasting to total costs, including the balance between capital and operating costs. The use of computer modelling is discussed, to demonstrate how blast performance and costs can be predicted and alternatives analysed. Case studies illustrate how cost savings can be made in operating mines, and alternative systems evaluated to optimise new projects.

Jan 1, 1990

By S Hapugoda, J R. Manuel, M J. Peterson

Microindentation testing using the square–pyramid–shaped Vickers indenter is a well-established technique to determine the microhardness of minerals and materials. However there is a paucity of published microhardness data from Fe ore samples. It is acknowledged that an iron ore’s particle mineralogy and texture is critical to its processing properties, and it is therefore considered that the microhardness of different mineralogical/textural types may also relate to these properties. Mineral microhardness potentially provides inputs to the modelling of breakage characteristics during comminution, as well as the relationship between mineral chemistry and microhardness, and mineral microporosity and microhardness. Microhardness can be determined as single crystal microhardness, for more coarsely microcrystalline samples, or as ‘aggregate microhardness’ for cryptocrystalline or finely microcrystalline samples.Variations in the texture and mineral chemistry of common Fe ore minerals (eg martite and microplaty hematite, ochreous and vitreous goethite etc) are well established and this study provides microhardness data on different textural forms of Fe (oxyhydr)oxides from a variety of different Fe ore deposits. The data indicated that in general, the mineral grain size, microporosity and texture were the main influences on Fe (oxyhydr)oxide microhardness. There were no apparent systematic variations between microhardness and minor element mineral chemistry, with the possible exception of Al content in goethite (for goethites with Al content >0.5 wt per cent), and for goethite total element contents >90 wt per cent (determined by electron probe microanalysis, EPMA). Higher Al concentrations and lower total element concentrations in goethite EPMA analyses correlated with lower goethite microhardness. Microporosity and grain size were more important than texture to hematite microhardness. Different textural forms of dense hematite (eg martite, recrystallised interlocking hematite and specular hematite) with similar grain size exhibited comparable microhardness. Microhardness values for hematite and hydrohematite with little or no evident microporosity were also similar, whereas more porous forms of martite, microplaty hematite or hydrohematite exhibited lower microhardness.CITATION:Peterson, M J, Manuel, J R and Hapugoda, S, 2017. Microhardness testing of hematite-goethite Fe ores – implications for their textural characterisation and geometallurgy, in Proceedings Iron Ore 2017, pp 319–330 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

The need for the hydraulic transportation of coal in the New South Wales coal industry, both from the coal face to the surface and from the coal mine to the consumer or the port for export, is explained. Details of research projects currently in'progress and involving the hydraulic transportation of New South Wales coals are given together with information on the hydraulic transportation of coal in the United States of America.The potential of hydraulic transportation as a viable alternative to the proposed expansion and upgrading of the New South Wales railway system to meet the projected New South Wales coal production to the year 2000 is described.

Jan 1, 1980

By Edmonds W, Jeffcoat R

The completion of the first two open hearth furnaces in the new No. 2 open hearth plant at Port Kembla will increase Australian production of steel by 350,000 tons of ingots per annum.The paper gives an outline of the essential features of open hearth design and auxiliary equipment required to operate the two modern open hearth furnaces at present being installed.INTRODUCTIONThe increasing demand for steel required by Australian secondary industries led to the decision to construct and operate No. 2 open hearth plant at Port Kembla. Two basic open hearth furnaces of the most modern design are under construction and it is anticipated that these units will be commissi.oned in September 1956. Australian steel capacity will thereby be increased by approximately 350,000 tons of ingots per annum.PLANT LAY-OUT AND CONSTRUCTIONIn the design and lay-out of this plant the emphasis has been on efficient material handling with simplicity of design and operation. Overseas methods were studied and these studies, together with experience gained at Newcastle and Port Kembla open hearth shops, enabled this plant to be built to a standard which compares favourably with any other in the industry.Initially two furnaces, each of 2,75 tons capacity, have been built, but provision has been made in. the design and lay-out to enable expansion to six furnaces.The location of the new plant in relation to the existing units will be noted in Fig. 5. It is one of the first units to be built in an area which will dovetail into a pattern for...

Jan 1, 1957

Theories of ore genesis. have both practical and philosophical application-practical in that they influence our search for new ore bodies; philosophical in that they provide a test for our theories of petrogenesis-and our ingenuity.For example, the theory of granitization requires an explanation of ore genesis compatible with the general concepts of granitization.Our understanding of some processes of ore formation, such as supergene enrichment, or the formation of residual lateritic iron ores, is so complete as to permit of nq controversy.For other ores, like the oolitic iron ores of England and France, and elsewhere, or the segregations of chromite or ilmenite in basic igneous rocks, the broad principles are generally agreed on; dispute is limited to details of process.But for a wide range of ore deposits there is no such agreement. Completely incompatible hypotheses are advanced to explain' identical facts, and we have difficulty in finding new facts or criteria that will distinguish unambiguously between them.In thinking about such ores, a co:n;venient starting point is provided by Schneiderhohn's (1953) fourfold division of ore deposits:1. The secondary hydrothermal ore deposits occurring in Mesozoic-Neozoic cover strata of Europe.2. The "regenerated" younger ore deposits in Alpine type mountain chains.3. Post-Cambrian primary hydrothermal ore deposits.4. Ore deposits of the PreCambrian shields.To these we may add a fifth group:5. Stratigraphically controlled sulphide deposits.

Jan 1, 1956

By N A. Sikwa, L M. van Niekerk, G N. Ndlovu

In June 2012, Lucara Diamond Corporation officially commissioned its Karowe Diamond Mine in Letlhakane, Botswana. The processing plant circuit incorporates variable speed autogeneous milling, a first for African diamond processing - only previously practiced in Russia. The paper discusses the basis for the selection of milling against the more traditional circuits incorporating crushing and scrubbing. It covers early commissioning challenges of operating a mill in an æalien environmentÆ with no immediate reference plant to look up to for bench-marking.The paper describes how these challenges were overcome and learnings quickly incorporated into the mill operating philosophy for maximum diamond liberation and minimum product damage. The plant was commissioned in three months and by August 2012 the production ramp up had reached name-plate capacity. The feed to the mill has varied from highly weathered material to extremely hard kimberlite and the operating philosophy had to be optimised for the full range of ore types. While more work is required to stretch the mill operating envelope coupled with other circuit additions to improve liberation of fine diamonds at minimum capital expenditure, the mill has, to date, performed to its billing.CITATION:van Niekerk, L M, Ndlovu, G N and Sikwa, N A, 2013. Commissioning and operating an autogeneous mill at Karowe Diamond Mine, in Proceedings MetPlant 2013 , pp 215-228 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

IN dealing with this subject the intention is not to write a detailed description of the various methods in vogue on the Kalgoorlie field, but rather to give a brief outline of three of the methods which are most universally in force, and from which, ultimately, a few comparisons may be drawn. The three methods which the writer proposes embodying in this article are known as "The Rill," "The Flatback," and "The Shrinkage." For comparative purposes each method will be applied to a block of ore 500 feet in length, and opened up by levels 200 feet apart."The Rin" System. It is necessary in this system, for facilitating mullocking, to make connections between levels by rising and winzing at about every 100 feet or 150 feet along the orebody. After the leading stope is beaten off for the full length ofthe drive, the level is timbered. Single stulls are put in up to a width of fourteen feet. If the span is too great for stulls, set timbers or saddleback stuUs are used. Stulls are lagged over with 4-in gimlet poles, and wooden chutes are built at intervals of 50-feet. Ore passes are cribbed up through the filling directly above each chute, and are constructed of 7-in. round timber or 9 in x 3 in square timber, the passes measuring 4 ft x 4 ft in the clear.Occasionally a double pass may be carried up, one side serving as a travelling way. Stoping is commenced off the winzes, and rills are gradually formed, one on either end of each winze. The rills are generally at an angle of 37° off the horizontal, this allowing for the boring...

Jan 1, 1909

During the last 125 years, the steel industry has witnessed revolutionary changes in the process of steelmaking. The Bessemer process was the predominant steel production technology during the last two decades of the 19th century. The open hearth process accounted for the lion's share of world steel production for six decades from 1910 to 1970. With the appearance of the LD process on the industrial stage in 1952, the importance of open hearth process declined and currently the basic oxygen processes are contributing more than 60 per cent of the world steel production. The LD process also led to the development of several other oxygen blown processes such as LDAC, OLP, OBM, QBOP, EOF, Clc.

Jan 1, 1999

By Firth B. A

The classification performance of a Dutch State Mines (DSM) Rapped Sieve Bend has been investigated in a series of experiments. Coal slurries of a nominal 0.5 mm size were classified in the separation range of 0.10 to 0.14 mm at pulp densities from 6 to 21 per cent by mass of solids, and flow rates of 110 to 1375 litre min-1.The results obtained showed that the partition curve and water split io oversize was dependent on the solids flow rather than slurry flow rate or pulp density. For most of the operating conditions considered an accurate classification of the fine coal was obtained. The undersize efficiency was susceptible to solids flow rate, and was less than 70 per cent for solids flow rates greater than 16.7 tonne hour-1 metre-1 width of screen.

Jan 1, 1983

Probably no other country or coutinent has so many rich deposits of various different minerals as Australia. Long ago in the days of my boyhood in the old land the marvellous discoveries of high percentage copper at Burra Burra, Peak Downs, Yudanamutana, and other mines, was one of the principal themes of conversation in mining circles whilst the specimens of malachite, azurite, etc, brought home by returning miners were the admiration of my boyish eyes.Later on the WalIaroo and Moonta mines still further helped to heighten the reputation of Australia as a copper-producing country. During the 21 years that the writer has been resident in the Australian colonies, other mineral deposits have sprung into prominence, and with a Mount Bischoff for tin, a Broken Hill for silver and lead, and a Mount Morgan for gold, Australia can now boast that it has had within its borders the leading mines of the world, in four different minerals, and still at least maintains that pre-eminence in gold, silver and tin. To the miner from the old land, Australian mining is at first a revelation and a wonder. In very many instances he looks in vain for the regular strike and dip of the veins he has been accustomed to'Smooth hanging and foot alls are often wanting. 'Huge irregular deposits, like those mentioned above, viz., Burra Burra, Mount Bischoff, Broken Hill, and Mount Morgan, are mysteries that will take time to fathom-if, indeed, they are ever thoroughly understood and in many a smaller deposit there is much to interest alike the professor in the college and the miner in the mine.

Removal of Thiocyanate from Solutions by Precipitation

Sep 13, 2010

By J Elsen, R Snellings, K Van Balen

This research concerns the mineralogical study of the physico-chemical reactions taking place at the pozzolan-binder interface. Lime binder/ pozzolan mixtures have been prepared for different natural zeolites. Analcime, phillipsite, chabazite, erionite, mordenite and clinoptilolite were mixed with portlandite and water, after which the progress in the reaction was quantitatively determined by thermogravimetrical analyses from three to 180 days. A first and important step was the thorough characterisation of the raw materials by quantitative X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscope energy- dispersive X-ray (SEM-EDX) measurements of the zeolite minerals, Brunauer-Emmet-Teller (BET) specific surface area measurements, grain-size analyses and cation exchange capacity measurements. Beside these zeolite samples with varying Si/Al ratios, two clinoptilolite samples exchanged to the calcium, potassium and sodium form were studied and the difference in their short- and long-term reactivity was assessed. Also the difference in reactivity between identical clinoptilolite samples ground to different grain sizes, obviously having different specific surface areas, was determined experimentally. The results indicate that the external surface area only influences the short-term reactivity, whereas the cation content has effect on both long- and short-term. Na-exchanged samples combine clearly more portlandite in the first few days, whereas the reaction slows down afterwards compared to K- and Ca-exchanged samples. The early reactivity of the unexchanged zeolite samples could be explained by these two parameters, but their long-term reactivity seemed to be related to their Si/Al ratio. Samples with zeolites rich in Si reacted faster then their Al-rich counterparts.

Jan 1, 2008

The following notes apply more especially to the purchase of silverlead ores produced in the neighbourhood of Zeehan and Dundas; for it is this class of ore that is principally mined in those parts, and which creates competition among the ore buyers.In the early days of this field, most of the ore passed through the hands of the first buyer who had sufficient enterprise to establish himself at Zeehan but in more recent times, competition has been so keen that there are generally three or four buyers tendering. lf the output was large this would not matter so much from the buyers' point of view but when we consider that the output of the field is only some 1,650 tons per month, and that of this 70 odd tons are produced by the Western and Montana mines, aud being sent home for realization, is withdrawn from local purchasers, there is really not enough for four buyers, especially at the present exorbitant prices they pay the miners.Some of the mines have a fixed sampling day, on which it is tacitly understood that the ore buyers will attend. Others, such as Grubb's Silver Mining Oompany, No-Liability, send round a printed reminder, stating the quantity of ore, and the date of sampling.

This paper is intended partly as a summary of the conclusions that have been arrived at by various authorities on this matter, and also with a view to initiate some discussion on the subject, especially as most of the quartz gold mines in Victoria are operated without having any proper assay plans or any idea of the real values other than those given by the mining managers, who, from experience in the particular cases, are supposed to be able to arrive at a correct idea of the true values of- the ore, and, in many cases, oppose any other methods than their own, holding the view that no sampling is equal in correctness to the bulk sample of the battery. The necessity of properly sampling and estimating the ore in a mine in every case, perhaps hardly needs to be urged on the members of the Institute, but is not, apparently, so obvious to others.It is proposed to confine this paper to the sampling of ore reserves in a mine, and the various points which have to be taken into consideration in arriving at values, from the assayer's point of view, leaving the methods of sampling metallurgical products out of consideration for the present. "It is advisable to define" ore reserves" as ore exposed on three sides at least, and accessible to the sampler on all three. "Prospective ore" would include all ore not so fully exposed; but which may, from the nature of the case, and the geological conditions prevailing, be reasonably supposed to exist.

Jan 1, 1904

By P Atkinson, M P. Simpson, J R. Kyle

BM37 is a bonanza-grade (>30 ppm Au) ore shoot of the Maria Lode of the Karangahake adularia-sericite epithermal deposit in the southern Hauraki Goldfield. Samples from BM37 contain up to weight percent gold. The ore shoot is a vein that pinches and swells, but is typically tens of cm thick, and locally exceeds 0.5 m in true width. Gold occurs as irregular anhedral electrum grains that range up to 300 microns across and contain 38 to 59 wt per cent Au (ave. 52 wt per cent Au). Electrum occurs in sulphide-rich bands in association with pyrite, chalcopyrite, acanthite, galena, sphalerite, and local covellite. Lower grade samples contain local to rare mckinstryite [(Ag, Cu) 2S] and polybasite [(Ag, Cu) 16 (As, Sb) 2S11]. Pyrite from BM37 is nearly stoichiometric; it lacks the As that commonly occurs at up to percent levels in pyrite from other veins in the goldfield. Acanthite also contains low quantities of trace metals, and typically has less than 2.5 per cent Se. The vein shows complex textures. Bonanza grade sulphide-rich ginguro bands form discrete layers adjacent to the vein margins, and occur as breccia fragments encased by later massive to comb quartz with local quartz after platy calcite. Both the breccia fragments and ginguro bands are cross-cut by later quartz veins. Textures thus indicate that formation of the high-grade portions of BM37 resulted from one or more discrete events that differed markedly from the events that formed the bulk of the vein.

Jan 1, 2006

The Golden Ridges Mine, one of the properties of New Guinea Goldfields Limited, is situated on the right bank of Nami Creek, not far from the township of Wau, in the Territory of New Guinea.The property is somewhat unique, in that the goldbearing ore-body occurs in the form of a flat seam-like deposit lying on a volcanic breccia, and covered with a mantle of overburden of decomposed porphyry. The overburden varies in thickness up to a maximum of about 65 ft.The ratio of overburden to ore is about 3 to 1. The practice developed is to strip the overburden by hydraulicking, and to mine the exposed ore under open-cut conditions, blasting to a vertical face, and using electrically operated scraper hoists for conveying the broken ore to the mill bins.The stripping of the overburden involves the boring of well-drill holes, blasting the holes and then hydraulicking the shattered material.

Jan 1, 1934

ALTHOUGH the development of the various flotation processes during the last 8 years has been so revolutionary, this development has been, until recently, entirely confined to the separation of the gangue from the mixed metalliferous sulphides.The desirability of finding some method of separating the independent sulphides from such a miXture, by means of flotation, has long been recognized. ThIS need was emphasized when the slimes resulting from the grinding of Broken Hill sulphide ores were for the first time successfully dealt with by the Mineral Separation Company's process on the Central mine. This process proved the practicability of separating the sulphides of lead and zinc as a mixed concentrate from the gangue present in slime. Although this was a very notable achievement, the process has not been generally used, owing to the mixed lead and zinc concentrates resulting from the treatment being acceptable neither to the zinc nor the lead smelters.Although the introduction of eucalyptus oil in minute quantities as an emulsifying agent has simplified the work of the subsequent tabling of mixed sulphide concentrates, rendering unnecessary the burning off or removal of the oil, there will always be a considerable quantity of slimy product too fine to settle on the moving surface of the concentrating machines, and therefore requiring other means for its division into lead and zinc concentrates.

Jan 1, 1912

Suggestions have been made at various times that there may be a recurrence of lodes similar to those at Kalgoorlie in the country to the south of the Golden Mile, but, so far as is known, there has been no geological evidence to support these suggestions apart from the possible extension of the younger quartz-dolerite greenstone in this direction.Geological mapping carried out by the writer in the Coolgardie district in 1946, provided some additional geological evidence to support this claim, and the ideas then held have since been expanded and are now considered to be sufficiently advanced to present them as concrete suggestions. As will be seen from the following pages, the critical area for lode prospecting is Hannan's Lake, where the basement rocks may include younger quartz dolerite greenstone, which, although perhaps distributed over a smaller area than at Kalgoorlie, could, on structural grounds, have a similar fracture system and similar ore deposition.There is little need to stress the importance discoveries in this area would have in prolonging the life of the field, and stimulating the post-war gold mining revival.Previous Work: Only the publications having a direct bearing on the preparation of this paper are given in the list of selected references, but the writer is very conscious of the fact that much other geological work has been carried out in the Kalgoorlie district since its discovery, by the W.A. Department of Mines, by mining companies, and others, all of which has contributed to the present knowledge of the field, and acknowledgment of the value of this work is given herewith. In presenting the suggestions in this paper a broad structural control of ore deposition is assumed, but this has already been established in other parts of the goldfields of Western Australia, including adjacent areas. In the early nineteen thirties, the Western Mining Corporation commenced work on the basis that there was a close relationship between geological structure and auriferous ore deposition, and a similar approach was first made by the Geological Survey of Western Australia in the South Yilgarn in 1935. These ideas were further developed during later surveys, particularly in the North Yilgarn and the Mount Margaret Goldfield.During the Coolgardie Survey in 1946, broad structural mapping was done in greater detail than before, and the structural ideas were implemented and further developed, leading to some success.Other work to which particular acknowledgment is given is that of Stiltwell, Gustafson and Miller, Forman, Prider and Finucane, at Kalgoorlie, and that of Honman in the Kalgoorlie-Coolgardie district, references to which are given at the end of this paper.Valuable constructive criticism of this paper has been given by Professor E. de C. Clarke and Dr. R. T. Prider, of the University of Western Australia.

Jan 1, 1950