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Review of the mining legislation in New Zealand has coincided with a number of radical changes. These include a redirection of economic management towards a more open and competitive economy; major reform of the state sector aimed at greater efficiency, transparency and accountability; a new environmental administration; and a fundamental review of policy for management of natural and physical resources. These changes provide an opportunity to develop a consistent and coherent approach in the minerals and related statutes that will achieve objectives of economic efficiency, equity, practicability and good environmental management.

Jan 1, 1987

By McIntosh A. H, Torlach J. A

Since the last paper on mining methods was presented to the Annual Conference of the Australasian Institute of Mining and Metallurgy in 1:960, numerous advances have been made in drilling and blasting techniques at Mount Morgan. This paper describes the drilling and blasting methods being employed in the open cut. The change over to track mounted percussion drills for all types of primary drilling is almost complete and new techniques such as detergent drilling and pressure loading of ANFO are being applied successfully.

Jan 1, 1965

Study on Flotation of the Low-Grade Magnesite Ore

Sep 13, 2010

The suitability of char from Yallourn brown coal as a filler for carbon electrodes used in the aluminium smelting industry has been assessed on the basis of the specifications usually laid down by electrode manufacturers for petroleum coke fillers. The purity specifications can be met by a simple acid leaching of the coal before carbonization. The true density of char produced at 1200°C is within 5 per cent of the specification figure, but the bulk density of char obtained from as-mined coal is only half that specified for petroleum coke.Although this can be increased to three-quarters of the specified figure by briquetting the coal before carbonization, further increases would be very difficult to achieve, as the remaining shortfall in density is due to an extensive microporosity developed in the particles of char during carbonization.

Jan 1, 1970

By S Henderson

The Thames gold-silver deposits are part of the Hauraki goldfield, situated within the Miocene to Pliocene calc-alkaline Coromandel Volcanic Zone (CVZ). The Waitangi vein system is one of the mineralised ore shoots in the Thames district. The Thames gold deposits are characterised by shallow level epithermal vein mineralisation with phyllic to advanced argillic alteration assemblages and abundant sulphide minerals including pyrite, arsenopyrite, chalcopyrite, galena and sphalerite. Gold occurs as electrum in association with sulphide minerals. Microprobe analyses.of sphalerite grains from the Waitangi deposit mostly range from 0.8 to 1.5 mole % FeS, although one sample contains 9.5 mole % FeS. Arsenopyrite from Waitangi yields a range from 33.1 to 34.6 atomic As (%). There is no discernible correlation between the FeS content of sphalerite and gold grade in the Waitangi deposit suggesting that gold deposition is probably not controlled by changes in temperature and activity of sulphur aS2 that control the FeS content of sphalerite. The possible causes for gold deposition are thought to be boiling, mixing and changes in pH. Sulphur isotope analyses of mixed sphalerite-galena and sphalerite-galena-ehalcopyrite samples yield a narrow range of d34SCDT values (-1.0 to 0.9 ë;n=5), whereas late spongy pyrite gives unusually light sulphur isotope values (-16.7 to -27.9 ë; n=4). The sulphur isotopic values of base metal sulphides from Waitangi suggest that the sulphur was derived from a magmatic source. However, the source of light sulphur in the late pyrite grains is not known. Preliminary fluid inclusion+studies indicate homogenisation temperatures between 173¦ and 284¦C and salinities of 0.23.0 NaCI equiv. wt % (uncorrected for C02). Vein quartz at Waitangi yields d18OSMOW values from 6.8 to 12.7 ë (n=23). The calculated oxygen isotopic composition of ore fluids is between -2.1 to 3.8 ë at 250¦C and -0.1-5.8 ë at 300¦C. Oxygen isotope analyses have revealed significant variations in d18O values with elevation and gold grades. Zones of gold enrichment coincide with a zone of variable oxygen isotope values at the top of the vein system, where boiling and/or fluid mixing most likely occurred. Oxygen isotope values varying with gold grades within the Waitangi conduits suggest that d18O values may be useful in targeting bonanza grade gold mineralisation in epithermal vein systems.

Jan 1, 1993

By Finlayson EJ

New detailed mapping, micropalaeont- ology and isotopic dating have been successful in revising the stratigraphy of Woodlark Island. All Middle to Late Miocene intrusives and volcanic rocks have been assigned to the Okiduse Volcanics. In addition, the results demonstrate that the Tabukui beds and Wonai Hill beds (N9, late Early Miocene to earliest Middle Miocene) are a single unit. Similarly, the Nasai and Suloga Limestones are confirmed as a single stratigraphic unit as they yield similar foraminiferal ages (upper Te, Early Miocene), and both occur in the same stratigraphic position unconformably overlying basement Loluai Volcanics. Radiocarbon dating suggests a latest Pleistocene age for the upper Kiriwina Formation. Extensive Quaternary cover and low relief prevents detailed structural airphoto interpretation. In general, the structure is simple with all units on Woodlark dipping to the northwest a_4 exhibiting prominent local block faulting.

Jan 1, 1991

Wetting Characteristics of Mineral Surfaces - Contact Angle Measurements through Molecular Dynamics Simulations

Sep 13, 2010

All previous attempts to cut rock in boring by means of revolving steel cutters have failed, chiefly in consequence of the mis-shapen teeth grinding the rock and themselves simultaneously, until, after a very few revolutions, the points of the cutters were so worn that it was impossible to force them into the strata. The diamond drilling plant being cumbrous, complicated, and costly, and seeing that fully 70 per cent of the boring generally needed is in what is known as the" milder strata," it will be readily understood that much of the work done will not pay a dividend on the outlay, so great is the cost of removal, the wear and tear of the machinery, and the loss of diamonds. The Calyx Drill, however, invented by Mr. F. Harley Davis, has been constructed so as to overcome these difficulties, and will penetrate quickly and .at a low cost this 70 per cent. of the milder strata. The Drill has taken ten years' hard work and thought to bring it to its present state of perfection, and it will now drill with steel cutters the 70 per cent of the work performed by the diamond drills at a greater speed and at about one third the cost of the latter.The utility of the diamond drill for certain work is undeniable, but it cannot by any means be described as a machine of general popular usefulness that is to say, it is quite beyond the reach of the great masses of mankind.

Although auriferous beach and fore-dune sands at Five Mile Beach south of Okarito township had been intensively mined by hand and primative mechanical methods drilling of the sandspit by the Gold Development Corporation in 1929 indicated that the grade and quantity of undisturbed black and grey sand below the water table was sufficient to support a mining operation. Worked sand above the water table also contained fair prospects. The Okarito Five Mile Beach Gold Dredging Co Ltd, was formed and an hydraulically powered, bucket ladder, sluice box dredge built. In 13 years of operation (1931 - 1943) the dredge returned 556.39 kg (17 890 oz) of gold at a recovered grade of 225.4 mg/m3. A total of ú42 000 was distributed as dividends on the ú30 000 capital investment. Recent drill and bulk sampling at the northern end of the beach has confirmed that reworking of the historic tailings by a modern gravity recovery plant would not be economic.

Jan 1, 1993

THE successful establishment of iron blast-furnace plants at Newcastle and Lithgow naturally invites attention to the economic utilization of the various products and by-products arising out of the industry.The general similarity in composition between Portland cement and iron blast-furnace slag very early attracted attention both in, the cement and iron-smelting industries. Probably the first use made of blast-furnace slag in the cementindustry was not of an honourable nature-viz, to use an almost worthless and cumbersome by-product as a not readily detectable adulterant in Portland cement, which was at that time very costly to manufacture.The astonishing discovery was made that in many cases the adulterated cement was stronger than the original unadulterated article. It was found that chilled blast-furnace slag introduced in moderate quantity and finely ground with the cement clinkerdid not injure, but usually improved, the quality of the resulting cement. This mode of, manufacture is recognized, especially in Germany, as a legitimate branch of the cement making industry.The use of slag for the manufacture of both slag cement and Portland cement has assumed very large proportions heth in USA and Europe so much so that in the former country plants not well situated and equipped for cheaply making cement from clay and limestone are being forced to close down. Slags from other than iron blast-furnaces, together with some of the latter, are not suitable for cement-making. All slags which disintegrate and fall into powder are wholly unfitted for cementmaking.Those highly charged with mineral oxide compounds...

Jan 1, 1918

IN previous discussions on the occurrence of gold in the Bendigo quartz reefs the opinion has been put forward that the gold shoots are primary concentrations in the quartz reefs during the period of vein-formation. The view has been based upon the constant features of the gold shoots in a large number of individual reefs, independent of their depth below the surface. These features include the mineral associations accompanying the gold, the appearance and association of the gold in the quartz, the similarity in all respects (excepting mineral content) between richly gold-bearing quartz and poor quartz, and the variations in mineral content in the reef apart from gold. The view has been supported by a relation of the gold shoots to faults, together with the dependence of the reefs on the existence of pre-mineral faulting. The secondary deposition of gold has only been observed in a few instances .associated with the younger monchiquite dykes, and is of no economic importance.

Jan 1, 1922

The interaction between ore-bearing fluids and the siliciclastic rocks typically hosting orogenic gold deposits in Phanerozoic metamorphic terrains result in the development of a distinctive alteration halo. Along with petrological changes such as the replacement of chlorite by carbonate and the growth of sericite, characteristic geochemical modifications take place within this alteration envelope. These include variations in elemental abundances and more or less pronounced shifts in the H, C, N, O, and S isotopic signature of the ore system. æFingerprintingÆ these isotopic trends can provide exploration with additional vectors towards the ore zone, and yields valuable information regarding the source of the hydrothermal fluids and the solutes contained therein. Data from radiogenic isotope systems such as Sr-Rb, Ar-Ar, Xe-Ra, Pb-Pb, Re-Os, Sm-Nd, and U-Pb can constrain the kinematic history of ore-hosting structures, provide important clues concerning the absolute timing of gold emplacement, and enable the detailed characterisation of associated intrusives with respect to their magma source(s) and crystallisation age. Although high analytical costs, long turn-around times and the potential for misinterpretation prevent isotope systems from offering a æquick & dirtyÆ analytical method that would provide a significant advantage in exploration for orogenic gold mineralisation, the development of integrated four-dimensional ore genesis models depends heavily on constraints obtained from isotope mass spectrometry.

Jan 1, 2002

When asked to lecture at Bendigo on the geological factors that determine the depths of ore deposits, I hesitated for a little before agreeing to lecture on the theory of deep ores in the city world famous as the pioneer of deep gold mining. If there be one place, wherein the conditions of deep-seated ore deposits should be sufficiently well understood, it is the city where the 180 mine made its bold plunge to previously neglected depths; and where the record of that famous mine has been broken by the skill of the managers, and the pluck of the proprietors, of the New Chum Railway and Lazarus mines.In the face of such practical triumphs, theoretical discussion may seem a waste of time, especially since it is often dedared that the existence of such deep-seated ores was denied by geological theory. This assertion is, however, startling since the oldest and best supported geoiogical theory of ore deposits, has taught for more than a century tliat ores must descend far below the regions of practical mining. This charge against Victorian geologists is generally based on opinions attributed to the late Sir Fredrick McCoy. It has been repeatedly affirmed that he declared that gold cannot occur pelow a depth of 300 feet. But so far I have not been able to discover that McCoy ever made any such assertion or ever held such a view.

Jan 1, 1902

By Moresby J. F

Segregation roasting was used to recover more than 85 per cent of copper from crushed, minus 14 mesh refractory furnace-lining bricks. A plus 14 mesh fraction: which was high in copper, could be recycled directly to the smelter, giving an overall recovery of approximately 90 per cent. An oxidation roast at about 700°C was necessary, before segregation roasting, to convert copper sulphides and copper metal to sulphates and oxides. Withsegregatron temperatures in the range 600°-650°C the quantities of solid carbon and NaCI required are 2-5 per cent and 1 per cent respectively. P.V.C. coating from scrap copper wire can be used instead of NaCl as asource of hydrogen chloride for the segregation reaction.

Jan 1, 1978

Samples weighing 0·5 g are decomposed with hydrofluoric and other acids. Most elements are extracted ftom the acid, aqueous solution by Alamine 336 (tricaprylyl tertiary amine) and thorium is determined in an aliquot taken from the aqueous phase by means of its reaction with arsenazo III. Concentrations down to 4 p.p,m. may be determined at a rate of 100 samples per man-day of 8 hr.

Jan 1, 1971

By A B. Christie

Known epithermal deposits in the Coromandel region belong to the low-sulphidation type, represented by three subtypes: (1) andesite-hosted epithermal Au-Ag, (2) rhyolite-hosted epithermal Au-Ag, and (3) andesite-hosted polymetallic veins. Paleo-depths for a range ofdeposits are estimated using various features including: paleo-surface indicators (e.g. sinters), hydrostatic pressures estimated from homogenisation temperature measurements on fluid inclusions, and alteration mineralogy. Paleo-depth estimates to the base of the ore zone for the rhyolite-hosted Coromandel deposits are in the range 200 to 500 m. Andesite-hosted Au-Ag deposits have more variable paleo-depths, and are deeper (up to 950 m) in those deposits with base metals at depth. The majority of Coromandel Au-Ag deposits have limited depth extents (<200 m) of economic grade mineralisation, although Waihi and Karangahake are notable exceptions with depth extents of 575 m and 700 m respectively. Limited depth extents of economic ore are a feature of epithermal systems worldwide and are commonly attributed to gold deposition from boiling fluids. Under hydrostatic conditions in epithermal/geothermal systems, boiling in an up-flowing hydrothermal fluid is controlled by the boiling point for depth (BPD) curve. From fluid inclusion studies of many low-sulphidation epithermal systems, deposition of electrum in economic concentrations appears to be confined to a temperature window of 260 to 180¦C. This means that for dilute, gas-poor fluids that follow the BPD curve, gold deposition is limited to a vertical depth zone of about 400 m, with its upper boundary at about 100 m below the ground surface. The greater depth extent at Waihi and Karangahake, can be explained by mixing of/a deep, hot (300¦C) fluid with cooler (c. 200¦C) heated ground waters. This has the effect of lowering the 260¦C isotherm by up to 300 m, thereby increasing the depth range of economic grade gold deposition within the 260 to 180¦Cwindow of electrum deposition.

Jan 1, 2000

The following brief observations on the mineral composition of the Mt. Oxide copper ore are intended to supplement the geological description of that ore-body recently published by Blanchard (2).'" The Mt. Oxide copper mine is situated about 45 miles W.N.W. of Dobbyn, in the Cloncurry district of Queensland (Fig. 1). A representative suite of specimens from the mine was obtained through the kindness of Mr. P. B. Nye, Executive Officer of the Aerial, Geological and Geophysical Survey of Northern Australia, and Mr. Jack Hall, the tributor of the Mt. Oxide mine. The specimens, as shown in Fig. 2, were nearly all from the sulphide zone, between the l04-ft. level and the 300-ft. level. Several additional specimens, together with information which will be referred to later were kindly sent to me by Mr. Roland Blanchard.MINERAL COMPOSITION OF THE COPPER OREThe mineral composition of the ore is relatively simple. It consists essentially of chalcocite, with varying, but minor figures...

Jan 1, 1940

By J Kelly, C Kelsey

The Autogenous Kelsey Axial Displacement (KAD) mill is essentially a short retention time centrifugal mill, designed to effectively harness extraordinarily high concentrations of input energy for efficient particle size reduction. The mill which has an operating duty band extending from primary to ultra-fine also has the unique capacity to generate fine and ultra-fine products from single stage size reductions of either coarse or fine mineral feeds, in both wet or dry operating modes. This paper covers developments following a recent optimisation programme which confirmed that mill shell speed and the velocity differential between the shell and the rotating internal disc assembly tips could be optimised in relation to specific energy for a given feed rate and feed size providing the product size remains constant. Subsequent test-work further demonstrated the versatility of the mill with duties ranging from the removal of surface contamination associated with heavy mineral concentrate particles to the production of premium ultra-fine talc, from a single stage of size reduction. Open circuit grinding of a rougher gravity concentrate to liberate gold ahead of leaching also highlighted the scope for the application of low cost KAD milling for a range of hydrometallurgical feed preparation duties, which involve fine and ultra-fine grinding.CITATION:Kelly, J and Kelsey, C, 2013. Advanced media-free fine and ultra-fine grinding - The Kelsey axial displacement mill, in Proceedings MetPlant 2013 , pp 152-161 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By Mech B

This paper gives a general description of mining practice at The Zinc Corporation Ltd., Broken Hill, New South Wales.The basic mining methods are those which have been common in Broken Hill for many years and have been well described in previous Proceedings. The main object of this paper is to indicate developments which have occurred in recent years and to describe changes in layout, mining methods and equipment which are taking place at present.The following headings have been adopted: History Geology and general characteristics of the orebodies, Geology, The lead lode, The zinc lode, General characteristics, Ore reserves, General mining method, Exploration and diamond drilling, Shafts and shaft sinking, Main shaft, Old main shaft, Block 5 shaft, New upcast airway, Development, Level interval, Level layout, Driving and crosscutting, Winzing, Rising, and Stope preparation.

Jan 1, 1946

Technologies are receiving a lot of 'press' - and rightly so; as they are seen as the means for achieving quantum leaps in productivity and cost reductions. A point of concern for Caterpillar is that we do not believe there is enough understanding of the infrastructure needed to support some of the future technologies, as well there is not enough utilisation of the current systems.

Jan 1, 1997