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The Rate Variable Batch Test (RVBT) - A Research Method of Characterising Ore Floatability

Sep 13, 2010

By A J. Eggers

With gold first discovered at Carrick in 1864, exploration and mining on the Carrick Goldfield in Central Otago, New Zealand, has now been ongoing for more than 130 years. Recorded historical hard rock production from up to 52 different mining claims from 1864 to about 1921 is 24,047 ounces (oz) of gold.   Since 1980 Amoco Minerals New Zealand Limited, CRA Exploration Pty. Limited, Amax Gold Mines New Zealand Limited and Summit Gold (New Zealand) Limited have conducted modem systematic exploration campaigns targeted at locating shear controlled gold bearing quartz lodes and stockwork deposits. More than NZ $1million has been spent by these companies on aerial photography, geological mapping, stream sediment surveys, soil and rock chip geochemistry as well as reverse circulation (RC) percussion and diamond drilling.   RC drilling by Summit Resources in 1997 has identified a 1,500 m long zone of low-grade gold mineralisation at Lower Carrick, with an average grade of 1.00 g/t Au over a 14 m average thickness. This gold mineralisation, hosted within a low angle shear zone, has analogies with the Hyde-Macraes Shear Zone in eastern Otago. Recent exploration and drilling at Carrick has revealed the potential to discover large (>0.5 million ounce (Moz)) low-grade bulk shear controlled quartz vein and stockwork gold deposits similar to those now being mined at Macraes.

Jan 1, 1997

By D Porta, E Grigolato, K Behrens

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Aug 12, 2013

Sphalerites from Devonian cassiterite-sulphide deposits and Pb-Zn-Ag fissure veins have similar ranges of Cd contents, but the average Cd and Fe contents could indicate a small initial difference in availability of Cd between the Zeehan-Renison Bell district and the Mt. Bischoff-Waratah district. Sphalerites from banded Pb-Zn deposits (Rosebery and Hercules) are characterized by low Cd content which is a world-wide feature of such deposits in exIrusive rocks, and may indicaIe a genetic relationship between ore deposition and vulcanism.

Jan 1, 1968

Coal Preparation Research at Turkish Coal Enterprises (TKI)

Sep 13, 2010

By J P. Ashby

Compared with elsewhere in the world, New Zealand quarries have tended to be mostly small. The reasons for this are a combination of the relatively high transport costs, low population density and a pioneering, self-employed attitude. The small size of the operations is reflected in low productivity, a tendency to repair and rebuild equipment rather than replace it, designed flexibility in the processing plant, minimal reserves investigation or development planning and a versatile and innovative work force who are generally not professionally trained. The Resource Management Act and the Health, Safety and Employment Act as well as a customer driven demand for higher quality and consistent products will have even greater influence upon future direction of the Industry. The trend will be towards fewer quarries operated by companies and professional managers that can adapt to the new demands.

Jan 1, 1993

By S Thomson, M Lovitt, T Purvis, C te Kloot, T Nguyen, Z Liu

Ernest Henry Mine (EHM), located in north-western Queensland, is an underground copper/gold sublevel caving operation currently producing over 6 Mt/a of ore. The mass mining method of sublevel caving (SLC) used at EHM involves systematically blasting a series of uphole rings in parallel ore drives and drawing the broken ore using a top-down approach. Each ore drive contains multiple precharged rings to prevent having to charge in close proximity to the brow of the previously fired ring; however, the current initiation system still involves ‘hooking up’ all detonator lead cords of the first precharged ring. The unstable nature of a rill and working close to a brow presents hazards to personnel completing the hook-up process. There is also a business risk of ore loss when damaged ground support completely prevents access to the next precharged ring. If the hook-up step could be eliminated, the risk to personnel and the business would be significantly reduced.EHM engaged Orica Mining Services in 2016 to trial their WebGenTM 100 – wireless electronic blasting system (WEBSTM) for the first time in an underground mining environment. Having successfully signal-tested the equipment, two test holes were initiated, followed by a single production ring and then multiple production rings. In total, 30 production rings were successfully fired underground at EHM in 2017. To do this, WEBSTM was successfully integrated into EHM’s current charging and firing process, resulting in no business delays or loss to production. None of the 30 rings required hooking up and all were initiated from the surface with no personnel underground. A high level of ownership from all personnel involved ensured the trial was a success, and provided scope for wireless detonators to be used successfully on a large scale – both at EHM and other sublevel caving operations. WEBSTM is now a proven example of technology that can be used to improve safety in the mining industry, through eliminating the need for personnel to work in hazardous areas.CITATION:te Kloot, C, Liu, Z, Purvis, T, Thomson, S, Lovitt, M and Nguyen, T, 2017. Improving safety through technology – Orica wireless electronic blasting system trials at Ernest Henry Mine, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 39–50 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

THE Broken Hill mining field, approximately 31 miles in length, is at present being exploited by seven companies, viz. : North Broken Hill Limited, Junction North Broken Hill No Liability, Broken Hill Proprietary Block 14 Company, Broken Hill ProprietaryCompany Limited, Sulphide Corporation Limited, Broken Hill South Limited, and Zinc Corporation Limited.The variation in size and shape of the ore-bodies in the mines of these companies, together with the many alterations in pitch and dip, necessitates differences in methods of mining, each company working out its problem in its own particular way.In the matter of chute construction for the handling of the ore broken in the stopes, each mine belonging to the above companies has adopted a style particularly its own, though it may be said that one or two of the types approximate very closely to each other, slight minor differences only being noticed in the design. It is the purpose of this paper to give a brief description of the principal types of chutes now in use in th,e various mines on the field, and in doing so they may roughly be classified into three groups, viz:1. Bulk Chutes, 2. Circular Chutes, 3. Square-set Chutes.The Bulk type of chute is used in the North and British mines of the North Broken Hill Limited, the Central and Junction mines of the Sulphide Corporation, the South Blocks mine of the Zinc Corporation, and the Block 14 mine.The Circular type of chute is used by the Broken Hill South mine and the South Blocks mine.The Square-set chute is used in the Proprietary mine, the Junction North mine, and occasionally in other mines where the square set method of mining is a necessity, and more particularly as mullock passes.

Jan 1, 1925

Procedures employing thiocyanate and dithiol complexes of molybdenum have been developed for the determination of the metal in the presence of large quantities of ferric iron. The procedures are developed for field application and it is possible to complete 200 analyses per day with laboratory accuracy. Use is made of sulphuric acid extraction and ascorbic acid reduction in the case of the thiocyanate procedure whilst the reducing system in the dithiol procedure is potassium iodide-sodium sulphite. Using a simple photometer the range of determination possible is 0-10~g for the thiocyanate procedure and 0-5 g for dithioI.INTRODUCTIONOf the many colorimetric procedures that have been developed for the determination of molybdenum only those using the thiocyanate or toluene-3, 4-dithiol complexes of the metal are sufficiently free from interference to be of use in geochemical prospecting. Rapid methods based on both these complexes 'have been developed at the. Broken Hill Division of The University of New South Wales as part of a general programme designed to improve geochemical procedures. Whilst speed rather than high accuracy is the important factor in prospecting, the aim of the programme is to develop procedures which will allow determination of 200· samples per man-day without loss of normal laboratory accuracy for the methods concerned.In most geochemical procedures visual estimation of a coloured complex is used in the determination of the quantity of metal present. At the high rate of sample determination of the improved methods this procedure places severe strain on the eyes. For this reason all methods are designed for determination by means of a simple filter photometer...

Jan 1, 1965

The Detachment of Coarse, Composite Particles from Bubbles

Sep 13, 2010

Interest in the tantalum-niobium minerals has been greatly stimulated in Western Australia by the fact that these rare minerals occur at numerous localities in that State, and in the adjoining parts of the Northern Territory, sometimes in mineable concentrations, as at Wodgina and Greenbushes. A large proportion of the world's tantalum comes from these deposits. The late Dr. E. S. Simpson, in particular, made an extensive study of the chemistry and mineralogy of these minerals, and the following observations are based upon the examination of specimens which he and Mr. H. Bawley, Government Mineralogist of Western Australia, have submitted to me for examination from time to time. The fact that so many of the specimens have been analysed provides a unique opportunity for the interpretation of the phenomena observed in the polished sections.TANTALITE-COLUMBITE SERIESIt has long been considered, on the basis of crystallographic form, chemical analyses, and specific gravity measurements, that ferrotantalite (FeO. Taz05), manganotantalite (MnO. Taz05)' ferrocolumbite (FeO. Nbz0 5), and manganocolumbite (MnO. Nbz0 5 ) form a complete isomorphous solid solution series (Simpson, 1937) and this is confirmed by study of polished sections of these minerals, Pehrman (1929) examined a series of five analysed specimens with Nbz0 5 contents as follows:-

Jan 1, 1940

By S M. Iveson, K P. Galvin, D Kumar

Dry separation of iron ore fines and other heavy minerals has previously been achieved using one of two main approaches. The first is an inclined table with an upward airflow via small holes to help form an autogenous dense medium. The second is based on fluidised beds comprising a dense medium formed by fine particles suspended in an upward flow of air. In either case, vibration can be introduced. This paper describes recent findings using a novel system referred to as the Sink-Hole Fluidiser, which utilises elements of both these two former approaches. This device consists of a conventional gas-fluidised bed of fine medium with a 1 mm aperture mesh located at the surface. This mesh contains relatively large holes that act as sink-holes. The fluidised media flows upwards through the sink-holes and then falls back into the fluidised bed via the fine apertures in the mesh. The particles being separated, which are much larger than the fine media, pass over these sink-holes, where they either sink or float. The sink-holes offer a more precise balance of forces, applied on a single particle basis, resulting in robust density separation.Experiments have been performed using 2.0–4.0 mm tracer particles of density varying from 2.4 to 4.8 relative densities (RD) separated in a 200 mm diameter Sink-Hole Fluidiser with a single 13 mm diameter centrally-located sink-hole. In this preliminary semi-batch work, it was found that the Sink-Hole Fluidiser was able to achieve sharp separations (Ep as low as 0.20). This work underpins the development of a new continuous steady-state Sink-Hole Fluidiser, applicable to the dry separation of iron ore fines.CITATION:Kumar, D, Iveson, S M and Galvin, K P, 2017. A novel sink-hole fluidisation method for dry separation of iron ore fines, in Proceedings Iron Ore 2017, pp 221–226 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Several Approaches to Enhance the Bioleaching of Enargite Some approaches were investigated to enhance the recovery of Cu from enargite by bioleaching with Acidithiobacillus ferrooxidans using the galvanic interaction with pyrite and activated carbon, and with thermophilic bacteria, Acidianus brierleyi. Addition of pyrite initially enhanced Cu leaching by the Galvanic effect, but after that the formation of secondary minerals passivated the surface of enargite in inoculated batches. Activated carbon improved Cu recovery from enargite much better than pyrite, when it is contacted with enargite. Recovery of Cu from enargite has been recorded to at largest 2.4 per cent within 30 days in the presence of activated carbon when mesophilic bacteria were inoculated at 25¦C. The recovery of Cu from enargite was drastically enhanced by inoculation of thermophilic bacteria, Acidianus brierleyi, up to 60 per cent within 40 days at 70¦C and still not leveled off after 40 days unless the formation of Fe(III) precipitates occurred. After 40 days dissolved molar ratio of Cu/As is around 5.2, suggesting that metal-deficient sulfides and/or ferric arsenate might be formed on the surface of enargite.

Sep 13, 2010

The use of walk-through inspections, approvals and ad hoc investigations to ensure risk is kept within acceptable levels is reaching its limits of effectiveness. Further improvement in occupational health and safety requires a systems approach, and the use of Quality Management principles is an obvious basis for this. SafeGuard, a æbest practiceÆ model health and safety management system and audit criteria based on AS/NZS ISO 9001:1994, has been produced by the Department of Mines and Energy. Quality style audits of mine and quarry health and safety systems are now being carried out by the Inspectorate.

Jan 1, 1998

Upgrading and Removing Phosphorus from Low-Grade and High Phosphorus Containing Iron Ores

Sep 13, 2010

The Effect of Ionic Strength of Plant Water on Valuable Mineral and Gangue Recovery in a Platinum Bearing Ore from the Merensky Reef

Sep 13, 2010

By T Albinson

Mexican epithermal deposits can be broadly grouped into two types based on their contained metals, distribution, associated igneous rocks and fluid inclusion compositions. Silver-gold deposits (eg Tayoltita) mostly occur in the western part of northernMexico where host rocks consist of Eocene, intermediate composition volcanic and intrusive rocks; fluid inclusion studies indicate that mineralising fluids were <300¦C and dilute (=3 eq. wt. % NaCl). In contrast, silver-lead-zinc deposits (eg Fresnillo) mostly occur in the central part of northern Mexico where they are temporally associated with Oligocene-Miocene volcanic rocks and intrusions of felsic composition, but commonly hosted within underlying Paleozoic-Mesozoic sedimentary rocks; fluid inclusion studies indicate that mineralizing fluids ranged from 200 to 400 ¦C and were saline (=10 eq. wt. % NaCl). The distribution of these two deposit types, crosscutting major crustal sutures, and the close spatial-temporal relationships between mineralisation and magmatism, together suggest that magmatic processes were more important in the formation of mineralising solutions, as a source of both ligands and metals, than the segments of crust hosting deposits.

Jan 1, 1995

Contents.SummaryIntroductionSituation, climate, topographyHistorySize of depositsPrevious investigationsGeological History of AreaMap compilationHistorical summaryNature and Significance of Granitic RocksSynchronous granitesMain subsequent granitesSignificance of types of bathylithsGeological StructureNorth-south anticlineCross-foldingFormation of channelwaysHydrothermal Depth-Zoning at CobarAssociation of Ores with PorphyryOrigin of replacement porphyriesTransgressive porphyriesSummary of ore-porphyry relationshipsSource of the Copper and GoldProspecting Targets, Cobar-NymageeGeneral ApplicationBroken HillThe Bendigo FieldKalgoorlie-Coolgardie, Western AustraliaConclusions

Jan 1, 1950

Using DEM to Model Industrial Banana Screens

Sep 13, 2010

Vitrinite reflectance forms the basis of a study of coal rank variation in two areas of the Upper Hunter Valley, New South Wales, on the northern margin of the Sydney Basin. A selective analysis procedure, based on samples rom twenty-two boreholes, has resulted in a small range of reflectance values for each sample and consequently a high degree of significance for calculated mean values. The patterns of rank distribution derived from these data have facilitated an interpretation of the rclative timing of coalilication and deformation in each area.This study provides support for the suggestion by several authors that there were at least two periods of folding in the tJpper Hunter Valley. In the Hebden-Ravensworth area, minor folding took place after most of the coalilication was completed.To the west, in the region of the Muswellbrook Anticline, coalification occurred during or after the formation of this major structure. Tectonic instability during deposition of the Singleton Super-Group, in the region of the Hunter-Thrust on the basin margin, is evidenced by rank variation suggesting differential subsidence across this zone.

Jan 1, 1980