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A homely simile will serve to epitomise an interpretation of the rock structures and associated phenomena of the block of country under review, as it appears to the writer.Disregarding the many thousands of feet of overburden that have been eroded away during the ages, the present denuded surface and rock systems below may be pictured as a slab of some titanie ribbon cake that has suffered much damage from rough handling and exposure, yet retaining much of the original symmetry of its superimposed layers of variegated colour and texture.Lateral pressure has crumpled the cake into a series of irregular corrugations and, in parts, has caused some of the layers to crush and slide over their neighbours.Following upon this squeeze, the cake has been severed into segments and rhomboidal slabs by vertical cuts, and these portions have been severely jostled one against its neighbour, crushing the faces of contact and dragging the contiguous layers in the direction of movement.The variegated icing of the cake is represented by intercalated sills of amphibolite, pegmatite, and aplite, and the body of the cake by highly altered sedimentary rocks.The icing has been assailed by the rats of erosion with such effect that only residuals of the original structures remain. The body of the cake has suffered successive waves of igneous invasion in the order of lode pegmatite, followed by zine, iron,copper, and finally by silver-lead. These successive invaders found difficult access, along certain of the vertical cuts, to the more succulent layers of the cake, where, gorging to repletion, many were imprisoned and entombed for the future service of mankind.

Jan 1, 1927

The 1981 Review: In the late 1970s there was an upsurge of interest in the prospecting and mining of this countryÆs mineral resources. That upsurge of interest was accompanied by a mounting public concern over the damage mining operations might do to the environment. Concern was also expressed about what some people perceived as inadequacies in the legislation which regulates mining and the grant of mining privileges, and inconsistencies in the relationship of that legislation to other legislation regulating land use and the use of resources.

Jan 1, 1984

As the chief field of the gold dredging industry in Otago is the district traversed by the Molyneux River (called above Cromwell the Clutha) and its tributaries, a brief reference to the geology of that region and the origin of its alluvial gold will not be out of place. The prevailing rocks are metamorphic schists, chiefly mica and quartz schists, pr.obably of Silurian age. Though these rocks do not contain many payable quartz reefs, gold appears to be distributed in small quantities all through them,chiefly associated with the quartz lamime and lenses. The river drift, however, contains numerous pebbles of quartzite, quartzoze conglomerate, and fme-grained slate. Seeing that these rocks are hardly known to occur in situ within the watershedof the Molyneux River, though Devonian and carboniferous rocks of similar character occur to the north-east and south-west, it seems probable that the schists were at one time overlaid by carboniferous and Devonian rocks, and that these have been removed by denuding agencies. Be this as it may, it is certain that the schists themselves have been greatly eroded by the action both of water and of ice, and that the resulting drifts have themselves, in many cases, been sorted and re-assorted by the same agents.Consequently the drifts are very varied in character and often developed on a grand scale. In geological age they vary from Early Tertiary (though some may be older) to Recent.

Jan 1, 1903

Application of Discrete Element Method for Simulating Feeding Conditions and Size Reduction in Cone Crushers

Sep 13, 2010

Evaluation of Grinding Medium Wear in Stirred Mills The standard fine grinding machines in the minerals industry are stirred mills whose performance largely depends on the competency of the grinding medium. Medium wear in stirred mills is one of the key parameters for medium selection. A wear evaluation methodology is developed and applied in this paper to measure the wear rate of river sand using a laboratory batch stirred mill. The procedure is demonstrated by testing the sand medium in a 0.55 kW batch stirred media detritor (SMD). The sand wear rate determined in the laboratory batch mill is successfully scaled up to that determined on a full-scale Metso 355 kW SMD mill.

Sep 13, 2010

The Development of a Non-Roasting Technology for Polymetallic Gold and Silver-Bearing Sulfide Concentrates Treatment

Sep 13, 2010

THE area dealt with in this paper is included within a radius of about 3 miles of the Poimena township. Several thousand tons of tin have been won from this field, and probably £200,000 spent in exploiting it.PREVIOUS LITERATUREThe field has been reported on by Government geologists on four occasions and several ,articles on it have appeared in the mining journals. The work done by Government geologists is summarized below:-"Report on the Blue Tier Tin Mining District and its Tin Deposits", 1886.Speaking of the tin-ore occurrences, this paper states:-"In the primary granite the lodes of tin ore occur, also dykes and belts of more recently obtruded porphyries. The really valuable metalliferous deposits may be classified as follows :-1. Lodes (of which the Lottah mine is typical).2. Dykes- (a) Indurated or hard (as shown by the formations at the Anchor and Cream Creek mines). (b) Soft (eg Hayley's Lease).

Jan 1, 1912

Alkaline leaching with sodium carbonate solution adjusted to pH 9·5 to 10·0 preferentially dissolves thorium from a mixture of rare earth and thorium hydroxides. Rare earth sodium carbonates form in the alkaline leaching stage.These are converted to rare earth oxides for use as optical and ophthalmic polishing agents. Quadrivalent cerium is extracted under similar alkaline leaching conditions.INTRODUCTIONAustralia has made significant contributions to mineral chemistry and mineral dressing. As often happens with an industrially immature country, research investigations often outstrip the ability or desire of commerce to exploit them. It is wrong to think exclusively in terms of export of raw materials. Imagination assists in developing world trends. The chemical utilization of mineral sands has interested a group of investigators, chiefly at the Commonwealth Scientific and Industrial Research Organization (C.S.I.R.O.) and, more recently, in the mining industry itself. From an international point of view the highlight of this work was Newnham's (1960) process for the separation of hafnium from zirconium. Earlier work at C.S.I.R.O. investigated the chlorination of rutile, zircon, and monazite. Assuming that titanium tetrachloride would be available in large quantities in the post war years, extensive work was done by Kraitzer, McTaggart, and Winter (1948) on organic compounds of titanium. This work led to the development of heat resistant paints, plastic compositions, and improved organic protective coatings that predated overseas work by up to seven years. (Post, Shiihara and Schwartz, 1961; Anon, 1955). Contributions were made to the production of refractory hard metals (Kraitzer, 1949; Kraitzer and Newnham, 1956). Pilkington and Wylie (1947) and Urie (1947) investigated the production of rare earths from monazite by an acid process.

Jan 1, 1963

By S H. Begg

There is strong evidence that many major oil and gas (O&G) projects are plagued by large cost and schedule overruns, or significant underperformance in productivity. Similar evidence exists for large mining projects. This paper claims that uncertainty is the underlying reason why projects fail to deliver the metrics used to justify their investment, or to deliver the economic value possible if alternative decisions had been made.Most technical and economic analyses are performed to reduce uncertainty to help make decisions. Decision-making is about ranking alternatives and choosing the best; rarely are precise predictions required, if this is even possible. Better uncertainty assessment is one of the keys to better decisions, thus better business outcomes. To get better decisions it is suggested that the focus or reward/penalty incentives be shifted away from the quality of outcomes to the quality of decisions. High-quality decisions are those that are generated from the skilled use of the tools, methodologies and processes from the discipline of decision analysis.Uncertainty is quantified by probability, which is a degree of belief in the truth/falsity of some proposition about a quantity relevant to a decision, such as volume of in-place resource, future price or action of a competitor. The probability a person ascribes to a proposition depends upon their information set; hence probability is subjective – it is not an inherent attribute of the quantity of interest or the physical system.The above simple observations have profound implications for modelling approaches, how they deal with uncertainty, the use of data to help assess uncertainty and the reliability of information provided by subject-matter experts. The limited circumstances under which frequency data (from spatial or temporal variables) can be used to assign probabilities is also reviewed.People, in general, are subject to a range of biases and cognitive errors. Research with O&G subject-matter experts shows that their expertise offers little or no protection from making errors in probability assessments and other judgements.CITATION:Begg, S H, 2016. Decisions, decisions – uncertainty, variability, modelling and psychology, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 9–18 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

The Application of Roasting Pretreatment for Antimonial Refractory Gold and Silver Ores

Sep 13, 2010

This study of the tin-tungsten ore of the Shepherd and Murphy Mine, in central northern Tasmania, was originally undertaken at the request of the Moina Tungsten-Tin Mining Co., N.L., as part of the research programme of the Mineragraphic Investigations Section of the C.S.I.R.O. It is based on the examination of a suite of specimens supplied by the management, supplemented by a more extensive collection and observations made by the author during a short visit to the mine in October, 1956.The Shepherd and Murphy Mine is at Moina, 36 miles S.W. of Devonport and 22 miles from Sheffield, the nearest railway station. It was worked almost· continuously from 1893 to 1919, when a fire destroyed the mill; to that date it had produced concentrates to the value of £141,000. After a long period of idleness, the mine was re-opened by the present company, but it has been announced recently that unfavourable market conditions have again forced closure.GENERAL GEOLOGYThe mine is on a deeply dissected plateau, about 2,500 ft. above sea level; it lies between the Iris and the Forth Rivers, whose valleys are deep gorges cut to about 400 to 600 ft. above sea level. From Moina westwards to the Iris River, a limestone regarded as part of the Gordon River Group, of Ordovician age, conformably overlies a sandstone containing tubicolar casts which are circular in cross section, half an inch in diameter and up to two feet long, and which resemble marine worm burrows (Elliston, 1953).

Jan 1, 1958

By Taylor G. H

The Triassic Ipswich (SE. Queensland) coals are of bituminous rank. The more exact rank of individual samples was determined by measuring the reflectance of the vitrinite. While in general the rank of the coals increases with stratigraphic depth, minor reversals, probably related to igneous intrusions, occur.The Ipswich coals form a coherent group so far as petrographic type is concerned. All are comparatively rich in vitrite and clarite, cutinite being the common maceral of the exinite group. The mineral contents of all the coals are comparatively high, clay and quartz being most abundant. The coals appear to be of essentially autochthonous origin, and to have been formed under conditions of fairly rapid subsidence.While the use of the coals is at present restricted to combustion, most have pronounced coking properties, as would be predicted from their petrographic composition and reflectance. However, the high mineral content of the coals would be a limiting factor in their use for coke-making.INTRODUCTIONDuring the last ten years, the Division of Coal Research, Commonwealth Scientific and Industrial Research Organization has carried out an extensive investigation of Australian coals, providing a wide range of analyses of most of the important of them. Special attention has been given in recent years to Queensland coals.Most seams were sampled as a number of subsections, enabling the internal variations, as well as the overall properties, to be assessed. The lenticularity of many of the mineralrich layers may tend to limit the significance of the samples, particularly in respect of ash yield, but although the vertical distribution of mineral matter may vary considerably from one sampling position to another, the lateral variation of the total mineral matter in the whole seam may not be great.Apart from extensive chemical analyses and utilization...

Jan 1, 1963

This paper discusses the social and economic impact of mining, and in particular goldmining, on New Zealand. The range of topics covered and their complexity has confined us in this paper to highlighting the main points of concern û a detailed report is under preparation. A major problem in undertaking this study was the lack of hard data on important environmental, economic and social issues and if there is to be effective planning in the area of natural resource use this situation must be rectified. The following conclusions were drawn: Goldmining was very important in shaping New Zealand's early social and economic development, providing wealth, employment and impetus for social change.Foreign investment and technology has been an essential element in New ZealandÆs economic development.Mining is a small industry at present by this must not be allowed to obscure its potential to broaden New Zealand's economic base and provide foreign exchange.With modern methods, development of mineral resources and environmental protection are not incompatible but certain unique and irreplaceable areas must be preserved.There are problems in evaluating mining and other projects because different groups hold different values, and arguments often hinge on the valuation of costs and benefits rather than the technical aspects of the analysis.Mineral exploration is a high risk business and the potential returns must be sufficient to attract capital if New Zealand's mineral resources are to be developed.A resurgence of goldmining will clearly have obvious benefits for Waihi but the local community must plan carefully for their future. New Zealand will also gain valuable foreign exchange required for higher levels of economic activity.

Jan 1, 1981

Study on the New Flow Sheet and Wastewater Recycling for Xiaoliuguo Copper-Bearing Low-Grade Scheelite Ore

Sep 13, 2010

By Beavis FC, Box JC

The important chemical and fluid flow phenomena in heap, dump and in situ leaching are summarised. Published, quantitative models of these processes are critically reviewed, and their potential applications outlined. Comparison between the independent predictions of one of the models and column leach test data reported by others confirms the potential. Some recent developments by the authors in the fields of fluid flow through unbroken ore and modelling of the more complex chemical systems are briefly Described.

Jan 1, 1981

By Kobayashi M, Kametani H

Particles of nickel flash furnace malle (45 per cent i) were oxidized in a dropping-particle furnace. The particles melted and the molten drops simulated those produced by the atomization of molten matte. The partly oxidized droplets were quenched and then reacted with silica flux to form high-grade matte (70 per cent i) and a fayalite slag. This paper describes the experimental equipment and deals with chemical aspects of the investigation such as volatile impurity distribution and thermodynamic considerations. The overall behaviour of minor elements such as Cu, Co, As and Pb was similar to that observed in conventional converting.

Jan 1, 1986

THIS paper is the outcome of experiments carried on and experience gained. at the Waihi-Paeroa Gold Extraction Company's tailings plant at Waihi, New Zealand. The plant was erected to treat accumulated tailings which had been discharged into the Chinemuri River by the Waihi batteries.The Chinemuri River is a common sludge channel for all mining debris, tailings, and ashes from the power plants, the last being the cause of occasional high residues, which gave so much trouble to the management. The tailings were dredged from the bed of the river into barges by means of a Pohle air lift, the power being supplied: by a 13 b.h.p. Tangye oil engine driving an air compressor and a centrifugal pump. The sands were elevated from the barges by bucket-belt elevators over screens, to eliminate large particles and rubbish, into storage hoppers, and from there fed direct into four C. Judd Ltd. tube mills.The method of treatment was fine grinding in a weak cyanide solution, agitation in B. and M. tanks, filtration with turn-over vacuum filters, and precipitation with zinc shavings. The comparatively high values of the residues in gold gave a great deal of trouble, 'and it was not until repeated experiments were carried out that the cause of the trouble was located. While the value of silver residues remained stationary, the gold values...

Jan 1, 1912

A study of the electrolysis of PbS in molten PbCl2 showed cathode efficiencies which increased with current density at fixed sulphide concentrations, and decreased with increasing sulphide concentration at fixed current densities. The anodically produced sulphur dissolved rapidly in the melt, the rate increasing with temperature and sulphide concentration. Experiments with diaphragm cells, made to determine the relative effects that dissolution of lead and sulphur have on the cathodic current efficiency, demonstrated that dissolution of sulphur was the major contributor to the lowering in efficiency.

Jan 1, 1973

Study on Influence that Styrene-Phosphoric has on the Surface Property of Rutile Minerals

Sep 13, 2010

By Kelly E. G

NZ Steel's flushing slag typically contains 1.2 per cent V203. Extraction of vanadium from powdered slag using a salt (NaCI or Na2CO3) roast/leach process was investigated. With NaCl, optimum extraction conditions were a charge containing 10 per cent NaCI, roasting in air at 875°C for 4 hours, followed by leaching in dilute H2SO4. Extractions were typically 30-50 per cent. NaCI roasting did not chemically attack the slag; the phase transformations that occurred were due to high temperature oxidation. Slag particle size had a significant effect on extraction.Optimum conditions for extracting vanadium by Na2C03 roasting were 20 per cent Na2CO3 in the charge and roasting in air for 3-4 hours at 850-875°C followed by water leaching.Na2CO3 roasting involved chemical attack that resulted in the formation of perovskite (CaTiO3) and carnegieite (NaAISiO4).The extent of vanadium extraction depended on the amount of Na2CO3 added and the original slag SiO2 content.Compared to the separate roasting treatments, simultaneous treatment with NaCI and Na2CO3 gave lower vanadium extraction, while requiring considerably higher roasting times and temperatures.

Jan 1, 1982