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Discovered in 1896, the Sons of Gwalia orebody is located in a ductile mylonite zone within a sequence of Archaean pillow metabasalts and minor metasediments of greenschist facies which are variably sheared.The ore zone has good continuity, being 110 m wide and 500 m long, dipping 45 degrees east and plunging 70 degrees to the south to a depth of 1500 m downplunge. A strongly-developed foliation is present together with a prominent lineation paralleling the plunge. The mylonite zone consists of unmineralised chlorite schist and a 'U' shaped mineralised zone of chlorite-sericite schist with varying amounts of quartz-carbonate as veins parallel to foliation, boudins, and locally as massive quartz-carbonate. Pyrite is the dominant sulphide present.Grade control utilises RC holes on a 10 m x 10 m pattern, with infill blast rig holes 5 m deep where necessary.Some visual control of ore boundaries is present and, combined with good ore continuity and a knowledge of the structure of the orebody, enables cost-effective grade control to be achieved. To-date, over three million ounces of gold have been produced from the orebody.

Jan 1, 1993

An improved method of sample recovery for use with rotary percussion drilling has been developed. Cuttings can be recovered continuously from either dry or wet drilling, and the recovery under dry conditions is seldom below 99% of the cuttings brought to the surface by the rig. The system is designed for use with top drive drilling rigs using flush-jointed drill rods. The key feature of the system is a self-aligning mechanical seal around the drill rods. The sealing unit is removably fixed to a collar section of cas ing. the cuttings are recovered in a plastic bag attached to the bottom outlet of a cyclone. A valve at the bottom of the cyclone permits the cuttings representing various depths to I,e recovered separately for examination eind 0(iclysis. [u the Iron Monarch quarry, two percussion holes were drilled to depths if 30 metres and 28 metres using the unproved sample recovery system, and diamond drill holes bored 1 metre from each percussion hole. Samples from each hole were sectionalized over metre intervals and analysed for iron, silica, alumina and loss on

Jan 1, 1976

By R Lurf, C Weber

In the frame of this paper a holistic dynamic process model approach is presented in order to introduce operational and technical excellence in drilling and blasting. Both on a macro and micro level the single process parts of drilling and blasting are outlined and their interaction is explained. The use of this approach for closing the gap between process planning and process implementation is explained and an example of the value generated is given.

Jan 1, 2007

By E S. B Santiago, C P. N Moreto, L V. S Monteiro, G H. C Melo, R P. Xavier

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Iron oxide-copper-gold (IOCG) systems of the Carajás mineral province (Amazon craton, Brazil) are structurally controlled by regional-scale shear zones and have formed by multiple episodes of fluid circulation and hydrothermal alteration in the Neoarchean (2.71–2.68 Ga and 2.56 Ga) and Palaeoproterozoic (1.90–1.87 Ga).Collectively, fluid inclusion, boron, oxygen and hydrogen isotope data and Cl/Br–Na/Cl ratios in fluid inclusions reveal that regional circulation of non-magmatic brines (eg evaporative fluids/evolved sea water) and mixing with other fluid sources (eg meteoric or magmatic) is an important attribute in the genesis of the Carajás IOCG systems. The ?33S and d34S compositions of sulfides from the Neoarchean and Palaeoproterozoic IOCG systems suggest that the ore-bearing fluids have assimilated sulfur from crustal reservoirs. Nevertheless, most ?33S measurements have indicated mass independent fractionation (MIF) effect for both systems which points to the possible involvement of surface sulfur sources.CITATION:Xavier, R P, Monteiro, L V S, Moreto, C P N, Melo, G H C and Santiago, E S B, 2015. Non-magmatic versus magmatic fluids in the genesis of Archean and Palaeoproterozoic iron oxide-copper-gold systems of the Carajás Mineral Province (Brazil), in Proceedings PACRIM 2015 Congress, pp 281–288 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Uranium minerals were found in Australia as early as 1869, but it was not until the 1940's that a search specifically for uranium was begun. Instrument types and techniques used in early exploration are still used today, but have been developed into more sophisticated and portable types. Recent improvements in exploration have been the introduction of the gamma ray spectrometer, radon sampling and geochemical surveys. The environments of presently defined uranium deposits are predominantly sedimentary. Known deposits in igneous environments are usually small. The size of targets which are likely to provide economic deposits is of the order of 10,000 tons U308, producible at a cost of less than $10 per pound. Such targets are most likely to be in Precambrian sediments or in granitic masses. Recent exploration in Australia has included investigation of Precambrian sediments, Precambrian and Palaeozoic granites, Mesozoic and Tertiary sediments, Precambrian volcanic rocks and brecciated masses of unknown age. The origin and method of emplacement of uranium in these environments is not well known but there are indications that syngenetic sedimentary processes are important, and volcanic rocks may make a major contribution to the supply of uranium.

Jan 1, 1970

By I KylmSkorpi, H Mansikkaviita

The traditional direct-heated drying process has been replaced by the steam drying process in non-ferrous metal smelters, where steam is available from waste heat boilers. Many recent projects have selected Kumera Steam Dryers in equipping a new production line or modifying an old production line. The industrial performance of the steam dryers has shown significant energy saving and emission reduction. The steam dryers have been operated at high availability and long maintenance interval. As the process principle of Kumera Steam Dryer is different from other equipment, the set-up for steam dryer plants is configured to fit the smelter site and operation conditions to achieve optimal performance. This article discusses the equipment involved in the steam drying process and their combination options.

Jan 1, 2008

Acclaimed as one of the most remarkable orebodies anywhere on account of its length and richness, the Oroya Shoot occurs on the eastern side of the Kalgoorlie gold mining district close to the contact of a fine-grained with a coarse-grained greenstone, and in association with sediments. In the same stratigraphic position on the synclinal flanks of a large drag fold there are a number of other flat ore pipes, smaller, but almost as rich in tenor. Although differing in control structure they are believed to be related genetically as all show a characteristic development of a bright-green ore known locally as "green leader". Folding and bedding structures have played an important part in formation of the ore shoots.INTRODUCTIONThe Oroya Shoot is the biggest individual bonanza of Kalgoorlie's Golden Mile. It has been stoped almost continuously over a length of 4,300 ft., and about 2,000,000 oz. of gold have been won from it. Naturally pillars are not left in the best sections of such an orebody and the detailed geology of stoped out portions can only be inferred from examination of adjacent workings.No mention is made in the literature of the actual makeup of the orebody although a few structures are shown on some of the old cross sections. A diagrammatic cross section, Fig. 1, adapted from Stillwell (1929) illustrates the form of the Oroya Shoot.Gustafson (1937) drew attention to the role of folding, previously unrecognized, in Kalgoorlie geology, and indicated that the Oroya Shoot is associated with a minor drag fold on the east limb of the Brownhill Syncline, itself part of a larger left hand drag on the Central Anticline. The latter in turn appears to be part of a regional right hand fold system as shown by Campbell (1953).

Jan 1, 1959

By Dickson B. L

Groundwater geochemistry is controlled by chemical interactions with aquifer rocks, and offers a powerful geochemical exploration technique for locating concealed mineral- isation. Techniques are applied for identifying constituents of aquifers using the compositions of their groundwaters, collected from the surface through drill holes, water bores or springs. Even slowly moving groundwaters have passed through large volumes of rocks which surround any sample site. Products from these rock-water contacts modify the groundwater. By relating water composition to the minerals from which the dissolved species may have been derived, geochemical exploration information is obtained for a significantly larger zone than is represented by drill hole rock samples. In this paper we describe some solution chemical tech- niques we are applying in mineral exploration, particularly in areas of Australia where ground- waters are highly saline and contain enhanced concentrations of trace metals. EQUILIBRIUM MODELS FOR SALINE GROUNDWATERS Central to our technique is the assumption that in low rainfall regions, aquifer rocks and contained groundwaters are in chemical equili- brium. Solubility calculations then allow us to predict upper limits to the soluble products of groundwater interaction with aquifer rocks and to identify minerals with which the groundwater is saturated. Whilst equilibrium calculations require input of concentrations of all dissolved species, they are actually based on "activity" of dissolved species rather than the analysed concentrations. Unless waters have very low ionic strengths (a measure of total dissolved solids), activity of a solute is not equal to its analytical concentration but equals concentration multiplied by an "activity coefficent". Several methods exist for calculating mineral solubilities. The ion-association model, commonly used in programs such as WATEQ (Truesdell and Jones, 1974) and later deriv- atives such as MINTEQ, assume the formation of complex ions such as MgSO4(0), CaCl+, which are described by formation constants. Activity coefficients are obtained by the extended Debye

Jan 1, 1988

By U Rehm

The biggest hard rock double-shield tunnel boring machine (TBM) in the world, with a diameter of 12.4 m, is currently excavating the North-South Bypass, which includes a crossing under the Brisbane River, Brisbane, Australia, to relieve the often congested road traffic in the city centre. Ten years ago a 10.7 m Mixshield giant helped to handle the Olympic Games in Sydney linking the airport with the city centre for an improved transportation of fascinated visitors. In Shanghai, currently the biggest TBM in the world with 15.43 m diameter presents excellent performance rates; and in Paris a convertible Mixshield could be quickly changed from earth pressure balanced (EPB) to slurry type in order to handle the very heterogeneous ground conditions. In Madrid a 15.2 m EPB giant finished its tunnel job four months ahead of schedule. Large-scale TBMs have proved their economic and innovative potential to create the current and future underground architecture of mega-cities. TBM technology has made further large innovative steps in the last decade. State-of-the-art is a TBM for very heterogeneous ground conditions comprising hard and soft rock with additional high groundwater pressure. The machine concept is adapted to the various ground conditions and allows for a quick and flexible application. Ground treatment by means of additives developed to a helpful tool in this connection. To meet the special challenges of urban tunnel projects of nowadays it is of very high importance, beside applying highest developed technology of TBM, to have a comprehensive technical support during the project phase and to develop positive relationships between all participants of the project which last longer than only for one project.

Jan 1, 2008

Ranger Uranium Mines Pty. Ltd. operates an open pit mine and ore treatment plant in the Northern Territory designed to produce 3 000 tonne/yr of U308 in yellowcake from 3 500 tonne/day of mill feed. The construction of this project was completed in 1981, 12 years after the discovery of the orebody. Wright-Davy, a Joint Venture of Wright Engineers and Davy McKee Pacific, were the Project Managers and Designers of the $270 million ore treatment plant and associated infrastructure. The project was designed in Sydney in -an office integrated with the Client, staffed by 35 key personnel drawn from Wright Engineers and Davy McKee, supplemented by personnel hired for the project. The peak Wright-Davy workforce in Sydney of 200 contained 113 design staff. The design principle of using the best practicable proven technology resulted in a plant which easily produces its design output using ore types outside the design criteria. The structuring of the project systems and industrial relations policies contributed to construction being completed within time and under budget. The plant was built without any major industrial dispute occurring and no dispute arose due to the uranium issue.

Jan 1, 1983

THE slag from the blast furnaces having been granulated, a representative sample is taken to the sample mill. It is then dried, crushed through a 100-mesh screen, intimately mixed, and packeted for assay purposes.METHOD OF ANALYSISINSOLUBLEWeigh 1 grm. of the finely-pulverized slag into a 3t-in. casserole, moisten with a little water to prevent sticking, cover with a clock glass, and add 20 cc. of hot acid (1 HNOs, 3 HCI, 4 H2 0). Evaporate slowly to dryness on a hot plate and bake (without overheating) until all the gelatinous silica is dehydrated. Cool, add 20 cc. HCI (1-1), and boil gently for several minutes; filter into a 300-cc. beaker, cleaning out the casserole thoroughly with a rubber-tipped glass rod. Wash residue with hot distilled water and transfer it to a No. 1 porcelain crucible. Dry, ignite, cool in a desiccator and weigh as total insoluble matter. Dilute filtrate to 200 cc. and neutralize some of the excess HCI with NHa.OH. Warm, and pass H2S for 15 min. Filter and wash withhot water. Boil off H2 S, oxidize with 5 cc. HNOll , reduce bulk of the solution by evaporation. to about 100 cc., and transfer to a 250 cc. flask.SILICAFuse insoluble residue over a blast lamp in a platinum crucible with three or four times its weight of anhydrous carbonate of soda, for 10 to 15 minutes, or until decomposition is complete. Cool, and extract fusion in an 8-in. evaporating dish with HCI (1-1); rinse crucible and cover with distilled water, and evaporate to dryness over a water bath. Take up dry mass with 10 cc. strong HCI, and then.

Jan 1, 1922

The T33-34 blast, the first major blast at Mount Isa Mines, broke 1,360,000 tonnes of copper ore using 349 tonnes of explosives. The original concept of firing T33, T34, T35 and U37 separately was changed during the life of the project due to adverse ground conditions. These conditions also caused the stoping method to be modified after the firing of the stopes had started. To stabilise the two stopes T33 and T34 where large fall off was occurring, rib pillars were left in the original slot. This caused the blast design to be more complex as these rib pillars had to "lead" the blast. The implication of such a large blast on the underground and surface environment was thoroughly investigated and precautions taken. The charging time of the blast was six weeks. Hook-up was started four days before the blast and continued until two hours prior to the blast. Detailed scheduling was carried out of other work that had to be done in the 24 hours before the blast to ensure that there were no delays in the firing.

Jan 1, 1977

By Koch DFA

An electrochemical study of the dissolution of gold in aerated cyanide solution has shown that the dissolution rate is determined b the nature of the surface. A passive film (probably a basic cyanide formed at .o.6 V vs a saturated calomel electrode inhibits both the ca.thodi reduction of oxygen. Some aspects of these retction mechcnisms are discussed together with the-"activating" effect of Thpllium.

Jan 1, 1964

By Adshead ND, Blake KL, Rotherham JF, Rotherham M, De Jong G

Magnetite deposits with distinctive ¦ actinolite ¦ apatite -bearing gangue and spatially-extensive sodic-calcic wall rock alteration occur in both Proterozoic metamorphic terrains and Mesozoic-Tertiary magmatic arcs. Examples from both settings constitute significant sources of iron ore (e.g. Kiruna, Sweden; El Romeral, Chile) and some host major Cu-Au deposits that have a local association with K-silicate alteration (e.g. Cloncurry district, NW Queensland; Copiapo district, Chile). A growing body of evidence points to a hydrothermal origin for these systems involving high temperature, low S oxidized fluids. The Cloncurry magnetite-Cu-Au deposits are products of the local structurally channelized influx of a specialized high salinity ore fluid into larger-scale alteration systems developed during pluton emplacement at greater depths than those associated with subvolcanic (porphyry) Cu-Au deposits. The geological characteristics of deposits in magmatic arcs are consistent with a similar mode of origin albeit in rather different tectonic settings.

Jan 1, 1995

The Coke Ovens Laboratory at Australian Iron & Steel, Port Kembla has been involved in the analysis of seam gases and mine airs for approximately twenty (20) years. This period has seen many developments and changes in the techniques used to the point when the current techniques are equal to other labora- tories involved in similar analyses. The laboratory has NATA registration for the analysis of mine airs and gases. Apart from routine testing of seam gases, ventilation airs and gases emmitted from coal bore cores a number of projects have been undertaken. These have served a twofold purpose, one to provide information to the customer, generally Collieries Research and Technology and secondly in developing the skills and capabilities of the Coke Ovens Laboratory. This paper discusses the development and services available at the Coke Ovens Laboratory for the analysis of gases and airs from collieries.

Jan 1, 1983

By Wu H. W, Jones S. J

Australia wide, over 40 fly-in/fly-out mining operations and other forms of long distance commuting now exist, with coverage of about 5000 employees. The substantial majority of these operations are in Western Australia, with some mines also located in Queensland and the Northern Territory. In recent years new large-scale mining operations have adopted the fly-in/fly-out approach and it is important to note that no new mining towns have been constructed in Australia since the township of Roxby Downs was built in the late-1980s to service the Olympic Dam mine. An examination of fly-in/fly-out mining operations in Australia has been undertaken. A detailed survey undertaken in 1990 has been reviewed and another intensive survey undertaken to establish emerging trends. Results from both company and individual employees point of view have been analysed. A section examines the views of professional employees and the influence of fly-in/fly-out on career development. Bus-in/bus-out coal mining operations are emerging in Queensland's Bowen Basin. These operations commute their employees into the mine site for compressed working schedules while the mine employees' families are domiciled in regional cities such as Mackay. A review of the issues associated with the development of long distance commute coal mining operations in Queensland's Bowen Basin is performed and two case studies examined.

Jan 1, 1997

By A E. Levett, J Durbin

The environmental, social and governance (ESG) obligations of mining companies promote the consideration of water and land resources as well as the post-mining employment opportunities following the cessation of mining operations. This work aims to outline the potential for a mining operation to use their brackish mine water resources to support microalgae production, generating high-quality organic carbon sources to support their mine rehabilitation and closure outcomes. Microalgae production is an established commercial process for high-value products including vitamins, cosmetics and food supplements. On mine sites, microalgae production offers several major environmental and social opportunities: (i) carbon capture, (ii) metalliferous water treatment, (iii) acid mine drainage prevention, (iv) beneficial reuse of brackish mine water, (v) accelerated soil formation and (vi) post-mining employment (Levett et al, 2023).

Aug 2, 2023

Callide Coalfields produces a sub-bituminous, very subhydrous, low rank, steaming coal with good combustion properties, primarily for domestic power generation. Geological input into planning of coal extraction requires expedient production of detailed structural, lithological, analytical, geophysical and geotechnical data. The CSIRO-developed SIROLOG borehole logging software and hardware system allows for detailed spectrometric analysis of coal/interburden. The gamma-gamma and neutron-gamma SIROLOG techniques both provide improved prediction of ash content over other borehole techniques. The neutron-gamma technique also predicts density and some important ash constituents (especially iron, alumina and silica). The software/hardware configuration allows for quick, easy interpretation of coal seam depth and lithology, parting thickness and ash/ash constituent contents immediately after a borehole has been logged. Within certain mine areas in the Callide Basin, the iron content of mined coal is widely variable in both vertical and lateral extent within and between seams. This variability creates problems in predicting the slagging behaviour of æas-receivedÆ coal during combustion, especially where the iron content of the ash exceeds 19 per cent. Using the SIROLOG tool in co-operation with traditional borehole sample laboratory analysis results, patterns in this variability can be determined and related to geological properties and process of formation of the coal seams. Subsequently, areas of high iron can be predicted in advance of mining. Since 1992, on-going collection and interpretation of SIROLOG downhole geophysical log data has significantly contributed to a number of research projects related to gaining a preliminary understanding of the iron distribution and formation during the Coal MeasuresÆ deposition. Because the probe was able to record variations in coal mineral matter content, it was found to complement more conventional techniques such as reflected light petrography, X-Ray Diffraction and SEM techniques that examine the mineralogy of iron species. Additionally, software has been developed to allow integration of SIROLOG data into existing geology databases, enhancing coal quality modelling and daily prediction of parameters such as raw ash, silica and iron contents that are indicators of ash fusion propensity. The correlation of SIROLOG-derived iron geophysical traces between drillholes and other sample points highlighted lithological and structural controls in the iron distribution in the sequence previously not detected. This work has allowed the development of a methodology for predicting iron in advance of mining and reconciling as-sold coal quality to that predicted. Predictions are currently being assessed at the coal face as mining progresses through high-iron zones.

Jan 1, 2000

By E de N, B H. Usher, F D. I Hodgson

Due to the haphazard application of static tests in South Africa, several methods and interpretations have been followed. This has resulted in confusion amongst practitioners and regulators in the use and validity of these methods. Research was done over a two-year period to define standardised methods and interpretation of results. This included laboratory testing and continuous consultation with all interested parties throughout the country. The research yielded a modified ABA, based on several existing methods. The methodology includes AP determination using hydrogen peroxide, and an analysis of the supernatant by ICP. This has the advantage of not only registering reactive sulfur, but also provides the NAG pH, that enhances the interpretation and QC of the tests. Analysis of the supernatant provides an indication of heavy metal solubilisation, should acid conditions arise. One hundred and seventeen samples were compared to Leco S analyses and provided a good correlation. The Leco values were slightly elevated due to the reporting of total S as opposed to æreactive SÆ. The NP method deviates from the usual methodology, in that H2SO4 is used (to provide a field analogy) and the fact that a 24-hour stabilisation period is allowed before back-titration. The latter modification appears to prevent psuedo-buffering by transient phases. These methods have also been tested for repeatability and prove to be robust. A very simple macro-driven spreadsheet, æABACUSÆ, was also developed. This spreadsheet allows the entry of basic data and provides a detailed interpretation and graphical display of typical ABA data. In cases where drill holes are used, the Pennsylvanian approach of volume calculation can also be done with ABACUS. The results of the research have been distributed to interested parties in South Africa and it is hoped that these methods and their application will find widespread acceptance.

Jan 1, 2003

This paper records the observations of faulting in the Black Star mine workings. By classifying the faults into two groups, i.e., strike faults and transverse faults, and by pointing out the differences between the groups and their effects on the silver-lead-zinc orebodies, a time relationship between the two groups of faults and the sulphide mineralisation is suggested.GENERAL GEOLOGY AND MINERALISATIONFolding and faulting are closely related to the mineralisation in the shales by silver-lead-zinc and iron sulphides.Commonly the various sulphides are fine-grained and closely associated with one another. However, exceptions do occur locally, where massive coarse galena, sphalerite, pyrite, and to a lesser extent chalcopyrite, have been observed singly or closely associated one with the other.In the main, the sulphide mineralisation forming the orebodies occurs as replacement of, and infilling along, the sheared bedding planes of the finely bedded shale host rock.The shales in general strike north-south with an average dip to 60° to the west; strong shearing along the bedding planes is evidenced by much slickensiding and slaty cleavage.Sequences of finely bedded shales of varying stratigraphic thicknesses alternate with very. massive beds, and it is in the more highly sheared thinner beds that the greatest concentration of sulphides occurs. The unmineraIised massive beds of shale, 11 in. up to 12 in. in thickness, occur singly or in groups between, and to a lesser extent. within, the orebodies. The massive beds resisted sulphide replacement and impart to the orebodies a most prominent banded structure.

Jan 1, 1953