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The Illawarra District, from 50 to 100 miles south of Sydney, is one of the State's important coalfields. It extends from Clifton on the north, to the Shoalhaven river on the south, and from the coast westward beyond the coastal scarp.For descriptive purposes, this area falls naturally into two zones:(a) the coastal belt backed-by the eastern edge of the plateau;(b) the plateau, westerly from the coastal scarp.(a) The Coastal Belt.A triangular shaped area extending from Clifton to the Shoalhaven river, composed for the most part of soft coal measures strata of Permian age, which, on weathering, undermines the massive overlying Mesozoic sandstones and causes the gradual recession of thecliffs.South of Wollongong, upper marine sediments and contemporaneous igneous rocks make their appearance beneath the coal measure beds and occupy the greater portion of the coastal belt.(b) Plateau Area.Extending westerly from the coastal escarpment is a plateau known as the Robertson Tableland, composed of Triassic sandstone and shales dipping gently in a northerly direction, and capped in places by Wianamatta. shales and r.rertiary basalts. This tableland is approximately 2400 feet above sea level in the vicinity of Robertson, and gradually falls to about 750 feet at Waterfall.The plateau area for the most part is highly dissected, rough, steep gorges alternate with sharp ridges.A large part of the northern watershed of the Robertson tableland is a reserve for Sydney water supply, and large dams have been constructed at Cataract, Avon, Burke, and Cordeaux.

Jan 1, 1938

Early in 1940 the development and sampling programmes in hand on the North and British Sections of North Broken Hill Limited were such as to necessitate the drilling of a large number of drill holes ranging up to about thirty feet in length. On the British Section, one purpose was to test the existence, width, and value of narrow lodes believed, for geological reasons, to occur in the walls of the existing workings. Another object was to definitely disprove the existence of payable shoots of ore in certain largerhodonite and quartz-garnet ("garnet sandstone") pillars which had been formerly left as unpayable.On the North Section, the main purpose of the short holes was to delineate the ore-body boundaries by drilling laterally from drives in ore, and thus enable level layout to be planned in advance of sill stoping. It was also desired to test the walls of stopes in those portions of the mine where the economic limit of mining is not rendered obvious by a clear-cut wall, but should be determined by assay. In these latter cases it was hoped to eliminate "prospecting by stoping," a procedure by which any doubts as to the existence of further good ore behind the low-grade walls were settled by continuing to stope laterally until all chance of such an occurrence was removed.LONG HOLE ROCK DRILLINGFollowing an investigation of recorded instances of similar practice elsewhere it was decided to use the rock drill for a series of trial sample holes. A 3-in. drifter was used. This was selected from those in use underground, and was given a special overhaul; had a new machine been purchased, a 4-in. type would probably have been obtained as being more suited to the work. The rods were H in. hollow round steel with a type "1" Jackrod thread. Couplings were of chrome steel, and were H in. in diameter, and 2 in. long. Jackbits (type "1" thread) in sizes from 2 in. to 4 in., with 1-in. gauge changes, gave a range of nine bit sizes. They were resharpened by hot milling, and were not milled to a definite gauge size.After sharpening, bits were sent underground without sorting into sizes, the drillers selecting the next bit with callipers. In view of the small scale of operations, it was not considered worth while to adopt special measures, such as the cold grinding of bits, which might have given a better product. Later, however, new bits were used exclusively, the idea being to accumulate enough blunt Jackbits to warrant a thorough treatment of the sharpening...

Jan 1, 1941

Every automatic citizen is an automatic recipient of a miner's right under the present Mining Act (Chapter 195), but this alone does not entitle any automatic citizen to mine for minerals on any land, even his customary group's land. Without complying with requirements of the Mining Act, any automatic citizen who engages in mining solely on the basis of a miner's right would be mining illegally. He would also be engaged in illegal mining if he mines on customary or other non-government land. Even if mining is legally pursued by an automatic citizen, he does not acquire ownership of minerals without first making the required royalty payments to the State.

Jan 1, 1991

By M Fallon

The full history of exploration successes, failures and related costs from initial greenfield exploration in 1987 to the current brownfield stages was analysed for the Plutonic Marymia Gold Belt of Western Australia. This belt, which had escaped the attention of turn-of-the-century prospectors and had not produced any gold until 1990, is an ideal area for a collectively exhaustive, progressive value and risk case study of expected return on gold exploration. The study analyses the progressive screening of over 200 greenfield and near mine prospects, through various stages of exploration to the establishment of 38 mining sites, ranging from a few large mines to small satellite operations. It provides empirical estimates of the historical Bayesian probability of projects advancing to successive stages of exploration, eg from reconnaissance, to systematic drill testing, resource delineation, feasibility and mine development, given a successful outcome in any exploration phase. The ratio between the estimated value of the gold discovered and the corresponding historical exploration expenditure in each year and cumulatively, ie the average cost of discovery per ounce of gold, are then computed as measures of historical return on the exploration investment in this belt. These, together with an estimate of the æresidualÆ gold endowment, ie of the number and size of possible as yet undiscovered deposits, generated through the use of rank statistics (ie ZipfÆs law), provide a basis for future strategic consideration in exploration targeting in this and similar geological terranes.

Jan 1, 2009

By L Lachance, F Flament, D Leroux, S GariTpy

"Considerable metal values are often locked in stockpiles (ore, concentrates, heap leach pads, slags, reverts, etc.) and process equipment (bins, holding tanks, thickeners, etc.). This is more than enough to justify accurate accounting of such in-process metal inventories from both financial accounting and operational perspective. However, accurately determining the metal inventory of an in-process unit is often a challenge in industrial practice. Audits have shown that available indirect or direct measurements often carry large inaccuracies. Sooner or later, ignoring these measurement errors lead to unexpected incoherencies in reported metal balances. In such situations, coherent metal balances are then achieved through subjective and sometimes significant adjustments of in-process inventory levels. While such metal accounting methods applied by mineral processing engineers used to be rarely challenged, they are now being increasingly scrutinised by various stakeholders. Hence, metal accounting procedures that mitigate subjectivity in adjustments while still coping with the unavoidable uncertainty are more relevant than ever.This paper reviews three different metal accounting methods for reporting in-process metal inventory values. Their individual application strongly depends on the available measurements i.e. The indirect method where the metal inventory of a given process unit is determined by subtracting the cumulative reclaim from the cumulative feed carries important flaws. The direct method also comes with challenging accuracy issues so that emptying a process unit is often the best available inventory measurement. This reality is recognised for by further analysing a previously proposed operating mode where two interchangeable process units are alternately used. The third investigated method is the redundant method which combines indirect and direct methods for a given process unit. This paper reveals that the dual process unit operating mode and the redundant method can both significantly improve the estimation quality of in-process metal inventories.CITATION:Lachance, L, GariTpy, S, Leroux, D and Flament, F, 2013. Review of metal accounting methods for in-process metal inventories, in Proceedings MetPlant 2013, pp 102-117 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 15, 2013

Despite a long history of production of industrial minerals and rocks, New South Wales still offers significant opportunities for exploration for and development of these minerals. Exploration for opal, sapphires, and zeolites in the State has been particularly encouraged by pioneering geological studies by the Department of Minerals and Energy, which have resulted in the development of important new geological concepts and exploration techniques. Large areas with potential for these minerals have not yet been tested. In the case of sapphires, the studies have identified a new type of deposit which is'the source of most of the sapphires mined from alluvial deposits. Recent price increases for heavy minerals, a re-evaluation of previous exploration in coastal regions, and a recognition of suitable environments in inland New South Wales have stimulated renewed exploration both onshore and offshore and have led to increased production. Significant potential also exists for development of a number of other minerals, including: topaz, which occurs in large, unusual and perhaps unique deposits in northern New South Wales; dimension stone (particularly granite); bentonite; diatomite; and silica for metallurgical use. Potential also exists for development of construction material resources, particularly construction sand, which is in short supply in the Sydney region.

Jan 1, 1989

By S R. La Brooy, T Giraudo, I C. Ritchie

The treatment plant at the Macraes Gold Project in New Zealand processes a carbonaceous, refractory sulphide gold ore. Since its commissioning in 1990, there has been a programme of continuous improvement of the plant, leading to higher recovery, increased throughput and low operating costs. During this time, a number of processes for treating both, or either, the preg-robbing carbonaceous fraction of the ore and the refractory sulfide fraction have been evaluated, trialed and utilised. The latest phase involves the installation by Minproc of plant utilising Newmont Gold's Pressure Oxidation Technology, a process which is anticipated to mitigate both problem factors when commissioned in 1999.

Jan 1, 1998

By W Herrmann, R R. Large

Volcanic-hosted massive sulfide (VHMS) deposits in ancient, submarine volcanic belts of Australia include mound, lens and sheet-style Zn-rich polymetallic deposits, massive and disseminated pyritic Cu-Au deposits and disseminated, stratabound Au-only deposits. Variation in morphologies, metal ratios, volcanic environments and alteration features indicates there exists a spectrum of deposits from the classic VHMS model, to hybrids between VHMS-porphyry Cu and VHMS-epithermal end members. Zn-rich, polymetallic deposits form eitheron, or just below, the seafloor, whereas the Cu-Au and Au-only deposits form sub-seafloor by replacement of specific volcanic lithologies. Alteration zoned outwards from quartz -> chlorite -> sericite ¦ carbonate is typical of VHMS deposits across the spectrum. Quartz and carbonate alteration is dominant in the Au-only systems,chlorite alteration is commonly developed close to Cu-rich ores, and sericite and carbonate alteration zones are well developed in the stratiform Zn-rich ores. The most useful geochemical vectors for Zn-rich ores are the alteration index [AI=100(MgO + K2O)/(MgO + K2O + CaO + Na2O)], the chlorite-carbonate-pyrite index [CCPI=100(MgO + FeO)/(MgO + FeO + K2O + Na2O)], Mn content of carbonate, Mg/(Mg+Fe) ratio of chlorite,whole-rock Tl, Sb and Ba/Sr ratio, S34S of pyrite, and whole-rock S18O. The most useful vectors for pyritic Cu-Au ores are AI, CCPI, S/Na2O ratio, Na content of white mica, and Fe content of carbonate.

Jan 1, 2002

By R Bezuidenhout, J K. Claflin, S R. La Brooy, G M. Wardell-Johnson, A M. Claflin

Best practice gold (Au) recovery is not an accident. It is the result of proper operation of the adsorption circuit using good quality activated carbon. A conventional carbon ‘regeneration’ kiln cannot process carbon fouled with floatation chemicals and achieve best practice gold recovery. A high temperature, controlled atmosphere carbon ‘reactivation’ kiln is required. Carbon circuit design allows for low quality carbon by increasing the carbon advance rate, carbon inventory and setting an easily achieved and commercially prudent solution tails target of typically 0.02 ppm Au. These design criteria are important to ensure the commercial success of the gold operation in the first instance. Most carbon ‘regeneration’ kilns will produce carbon of sufficient quality to achieve a 0.02 ppm Au solution tail in the absence of flotation reagents.Best practice recovery is considered less than 0.005 ppm Au in solution reporting to tails. If the carbon is heavily fouled, as it will be if used for flotation leach circuits, then a conventional carbon ‘regeneration’ kiln cannot achieve world’s best practice recovery no matter how much carbon is advanced. World’s best practice gold recovery requires a carbon ‘reactivation’ kiln and the whole of the carbon circuit operated optimally.The competing reactions occurring in a carbon ‘reactivation’ kiln are presented and discussed in terms of kiln design and operation. New industrial and laboratory findings are presented to fill gaps in the body of knowledge and identify that a large reduction in residence time at temperature will not significantly impair reactivation, but can significantly reduce the size and cost of the kiln or permit significantly increased carbon throughput.The carbon circuit performance is modelled in terms of gold adsorption, as a function of carbon reactivation using ‘simulation of carbon-in-leach/carbon-in-pulp circuits’ (SIMCIL). An optimum carbon advance rate is identified as a function of optimum carbon ‘reactivation’ kiln operation to achieve 0.005 ppm Au in the tails solution. A conventional carbon ‘regeneration’ kiln is compared to a state-of-the-art carbon ‘reactivation’ kiln in terms of reactivation performance and gold recovery.CITATION:Claflin, J K, La Brooy, S R, Wardell-Johnson, G M, Bezuidenhout, R and Claflin, A M, 2017. Optimising carbon reactivation kiln operation, in Proceedings MetPlant 2017, pp 346–364 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

Mr Kapp's paper helps considerably to clarify the subsidence/mine geometry relationships in New South Wales. It is in the best tradition of the presentation of field investigations such as has built up internationalknowledge over the years.The Author has plotted in Fig. 10, the maximum subsidence developed over each of a number of panels of different width/depth ratios and concludes that the maximum possible subsidence over a super critical extractionarea is around 0.65 of the mining height and that this is reached with the critical width/depth ratio of extraction of around 1.5.Although, as Mr. Kapp says, the maximum possible subsidence in the UK can reach 90% of the seam thickness extracted the more usual figure for the first seam is up to 80%. It has also been found in the UK that with shallow workings such as those at Kemiro Coliery the critical width of extraction is 2.0 or more times the depth.

Jan 1, 1981

CONTENTS: Broken Hill The mixing stations.Operating and mixing apparatus.Pulp distribution.Stope preparation.Filling procedure.Consolidation of old fill.Drainage:Pulp density tests. Life of sand pipe lines.Results.Advantages and disadvantages.Conclusion and acknowledgments.General remarks on South Limited.Mining methods.History of stope filling in Broken Hill.Need for a new and better filling method and transport system.Initial experiments with hydraulic stowing.Source of the sand.Water Supply.Signalling system.GENERAL REMARKS ON BROKEN HILL SOUTH LIMITEDThe South Mine, property of Broken Hill South Limited, is situated at Broken Hill, N.S.W., Australia, towards the southern end of the main lode.The leases (M.L's 7 and 8)' cover a length of 2,400 feet along the lode outcrop and the workings extend, at this date, to a depth of 1,940 feet below the collar of the original main shaft and to 825 feet below sea level.Mining operations have been continuous for about 58 years and during this period nearly 12.5 million tons of ore have been mined. The monthly tonnage extracted approximates 30,000 tons in normal times.The ore is a mixed sulphide containing galena and marmatite; the gangue minerals are principally calcite, rhodonite, quartz and garnet.A typical assay for a monthly period is 14·40/0 Pb., 5·6 ozs. Ag., and 11· 60/0 Zn. The whole of the ore is concentrated on the property by combined gravity and flotation methods. The lead and 'zinc concentrates produced are railed to other centres for the extraction of the contained metals.MINING METHODSMining practice throughout the field varies only in minor details. The ore-bodies forming the Broken Hill Lode lie within complex folds arranged along a shear and vary in size and mineralogical associations, but all the mines have similar types. Some of the ore-bodies have weak walls, but the chief difficulty in mining is caused by "heads" and "flaws" in the ore.Besides these local weak areas there are ground movements-referred to later-of varying magnitude extending throughout the central portion of the lode where the large ore-bodies, several hundred feet wide, approached the surface.

Jan 1, 1944

Plant-Based Trials of Monitoring of Coal Flotation Systems Using Electrical Impedance Spectrum Technique

Sep 13, 2010

I HAVE to thank the members of the Institute most cordially for the honour conferred upon me in selecting me President, which position my poor services have prevented my filling adequately. I have, therefore only been able to stumble through my year of office under the guiding direction of our esteemed Secretary. I fully appreciate the honour done to me; and, now that it is over, I can look back with pride and pleasure at having occupied the chair; but I am told that it remains for me to fill one of the requirements of our Institute and present you with what has been dignified by the name of a presidential address. My relief in complying with this is in the knowledge of its freedom from the usual discussion which appertains to papers presented by our worthy members. It has been usual in the past for the subject chosen to be specially connected with the work immediately engaging the attention of your president, and on this occasion I would like to break away from this time-honoured custom and engage your attention for a brief space on what is equally dear to us all namely, Ideals of the Profession. In doing so, the retort of Whistler to an art student gives me, I must admit, much misgiving, for, on being asked how he developed his artistic talents, replied that he painted what he saw, which produced the immediate reply, "Ah, but the tragedy will come when you see what...

Jan 1, 1909

By D Preedy, J K. Claflin, S R. La Brooy

A gold mine in north-eastern Africa has expanded throughput from 5 to 10 Mt/y in recent years. The original carbon regeneration kiln was incapable of achieving required throughput or meeting process conditions to reactivate the carbon due to heavy fouling by high molecular weight frothers and collectors. A new high temperature kiln was required.The design criteria for the carbon reactivation kiln and associated equipment were revised, then implemented in close cooperation with a kiln vender who had previously supplied kilns operating successfully on highly fouled carbon. The result is a whole facility, holistically designed to achieve the technical criteria.The new carbon reactivation facility has been operating since 1 July 2014. What have we learned? What has performed to expectations? What could be done better?This paper presents lessons learnt regarding the design, implementation, operation and maintenance of the Ausenco Carbon Reactivation Kiln. ‘Lessons’ are associated with threats and opportunities (risks) that have that have been realised. The importance of identifying and managing risks for even small straightforward projects is demonstrated.CITATION:Claflin, J K, La Brooy, S R and Preedy, D, 2015. Lessons learnt and performance – installing and commissioning an Ausenco carbon reactivation kiln in Africa, in Proceedings MetPlant 2015, pp 163–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

The El Pe±on gold-silver deposit comprises four epithermal, low-sulfidation veins, which contain 2.9 million oz Au and 48 million oz Ag. Provisional data on alteration mineralogy, fluid inclusions, and vein textures constrain the chemistry and hydrology of the hydrothermal system responsible for ore mineralisation at El Pe±on. Alteration minerals include quartz, adularia, albite, illite, smectite, calcite, chlorite, and pyrite. Alteration minerals suggest the existence of near neutral pH, low salinity hydrothermal fluids, which circulated over an area greater than 18 km2. Complex mineral zonation patterns result from variations in host rock permeability and composition, overprinting alteration possibly produced by thermal waters from surficial and peripheral parts of the hydrothermal system, and supergene weathering in the hyperarid environment. Upflow zones were focused along N-S and NE trending structures, producing crustiform quartz-adularia+carbonate veins. Fluid inclusion data indicate vein deposition from low salinity (

Jan 1, 2002

Ok Tedi Mining Limited has recently completed the first phase of a trial to compare the performance of D26B Krebs cyclones in different configurations to the new Warman 650 mm CAVEX cyclones. From 1992, rougher flotation feed size has increased from the target d80 grind size of 150 ¦m with increasing SAG mill throughput. At high SAG mill throughput, operators have difficulty maintaining the target cyclone feed pressure and must increase the cyclone feed density, thus resulting in a coarsening of the cyclone split. Warman International have developed the CAVEX high capacity cyclone. The new CAVEX cyclones, when compared to the Krebs units appear to:produce a measurable increase in volumetric flow for the same pressure drop; maintain or decrease the proportion of coarse particles reporting to overflow; and lower the overflow density. In all plant trials to-date, the CAVEX cyclones appear to be superior to the standard Ok Tedi Krebs cyclones. Further testwork is planned to evaluate modified Krebs cyclones (with recent design improvements) against the CAVEX cyclones.

Jan 1, 2000

Detailed investigation was carried out on the dephosphorization of a number of phosphorus-rich manganese or samples of India by leaching with dilute sulphuric acid. Various process parameters like concentration of acid, liquid-solid ratio, temperature of leaching, time of leaching, and particle size of the ore were studied in detail for the three samples of manganese ore from central India, and optimum values were worked out on a laboratory scale. Preliminary studies show that certain ores which are not easily amemlible to appreciable dephosphorization by leaching with dilute sulphuric acid can be made amenable by :roasting to 700-900°C before leaching.

Jan 1, 1974

Mineral deposits of the central New Guinea region (Gunung Bijih, Ok Tedi, Mount Kare, Porgera, Frieda River) and of southeastern New Guinea (Wau-Edie Creek, Wafi, Hamata, Hidden Valley, Tolukuma, Misima) are associated with hot, forceful intrusions of magma of mantle origin that penetrated thick Precambrian and Palaeozoic continental crust. The interaction of high- temperature melt with continental crust, and the differentiation of melt while in transit through thick crust, may be factors in generating ore. Mineralised intrusives in central New Guinea are a result of Neogene- Quaternary magmatism and were emplaced in a foreland thrust belt environment, a setting similar to the (mineralised) Laramide intrusions of southwestern USA. In both cases, central New Guinea and the Laramide, magmatism is not obviously subduction- related. Mineralised intrusives in south- eastern New Guinea (Wau-Edie Creek, etc.), also, are in a thrust belt setting, and are not obviously subduction-related. The association of. gold in southeastern New Guinea with a second (Pliocene) phase of igneous activity, rather than with earlier (Miocene) activity suggests that re-working by successive intrusions may be a factor in localising ore. This is seen, also, in the Bismarck-Solomon islands region where the richer deposits are associated with later (Pliocene) intrusives rather than with earlier (Eocene-Oligocene) intrusives. Unlike the mainland mineral deposits, those of the Bismarck-Solomon islands are clearly subduction-related.

Jan 1, 1991

Multiple regression analysis was used to predict elemental concentrations of copper and nickel in soils from consideration of the concentration of these elements in vegetation in an ultrabasic complex in New Zealand. Regression equations were computed from sixteen independent variables involving concentrations of ten elements in plant ash, and various physical factors such as slope and altitude of the site, and height of the tree. One elemental and one physical variable were significant for nickel at the 90 per cent level of probability and five elemental and two physical variables were significant for copper at the same level. Use of the regression equations explained 32·5 per cent and 26·5 per cent of the variance in the respective relative accumulations (amount in plant divided by amount in soil) of copper and nickel.Predicted concentrations of copper and nickel in soils agreed more closely with the observed values in the soils than did the levels of these elements in plant ash.Although the results may specifically apply only to the test area, the principles should have universal application.

Jan 1, 1972

Same-batch and non-blind as well as blind pulp duplicates are often submitted as quality assurance/quality control (QA/QC) control samples to a routine laboratory along with routine assays (and other control samples such as reference material samples). The current ways of interpreting the results of duplicate assays to derive QA/QC conclusions and decisions, however, has not yet been formalised in a scientific manner. The current, prevailing approach and its limitations are reviewed and a new method is proposed as a substitute tool. This new tool should allow for operational error detection on a batch per batch basis (ie batch rejection) as well as laboratory performance assessment with time on reproducibility.

Jan 1, 2008