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Total extraction is a misnomer and invariably some coal losses occur in the mining of pillars. "Fulls" pillar extraction is by the pocket and fender method, the splitting method or the open end method, with extraction in the pillar, and in rows of pillars in planned sequence, using combinations of coal and timber and roof-bolts for support. Where circumstances dictate, partial extraction is used, leaving behind portions of pillars in large blocks for support. The use of such extraction plans and supports as minimum guidelines has contributed greatly to safety in United States Coal Mines.

Jan 1, 1974

By Yates M. G, Rowlands A. T

Most geostatistical techniques applied to the estimation of ore reserves assume relatively unifonn grade and thickness within an ore deposit environment. In shear-hosted mineralisation this rarely occurs. The distribution of mineralisation is controlled by the kinematic and geometric variation within the shear zone. Although the kinematic variation is dependent primarily on the temperature (and consequently the depth) of formation of the deposit, the geometric variation appears to be relatively insensitive to this parameter. Shoot mineralisation is controlled either by the intersection of secoodary shear planes (brittle deformation) or the stretching lineation of the mylonitic fabric (ductile defonnation).Once the shear geometry is clearly identified, it is critical to review the distribution of grade and thickness of mineralisation. The practice of cutting high-grade intersections without reference to the shear model leads to underestimation of the amount of gold in the deposit. High-grade shoots may occur as pipe-shaped bodies within the system; their identification is essential for both resource estimation and mine planning purposes.

Jan 1, 1991

By Braaksma M, Dudley K

The Girilambone Copper Mine is located in central New South Wales and has been operational since May 1993. Girilambone is operated by the Girilambone Copper Company (GCC) which is a joint venture between Straits Resources (60 per cent) and Nord Resources (40 per cent). The mine complex consists of an open cut pit, ore crushing and stacking, heap leaching, solvent extraction (SX) and electrowinning (EW) allowing for the recovery of 14 600 tpa of LME grade A cathode copper. The leaching and SX-EW plant have been described previously by Rear, Taylor and Busby (1994) and Miller (1994).

Jan 1, 1996

By Leach B. G

A geostatistical study was made of diamond drill hole intersections within 18CC stope block at the C.S.A. Mine, Cobar, N.S.W. The stope block is located in 18CC orebody which is a massive sulphide - multiple vein, Copper-Zinc type, lacking clear definition on gangue mineralogy, base-metal assays and total sulphide considerations. Of the variograms constructed for inter- section width and copper, lead and zinc grades and accumulations, only zinc displayed behaviour amenable to model fitting and kriging procedures. Zinc grades were calcu- lated for sub-blocks comprising the total stope block and comparison with equivalent grades determined by traditional methods showed them to be generally less extreme in the highest and lowest grade sub-blocks. The total-block grades derived by the two methods were almost the same. It is suggested that the failure of copper to show variogram continuity might reflect the difficulty in defining the actual 18CC orebody, a proposition which is supported by the poor continuity in the variogram of horizontal width. In the case of lead the poor continuity may be due to the frequent manner of occurrence of galena as coarse grained patches of limited extent. The results of the study, did not provide a convincing reason to depart from the traditi- onal methods of grade estimation at the C.S.A. Mine.

Jan 1, 1979

By C Lower

An unprecedented, quantitative, deposit-scale understanding of major clay mineral distribution throughout the Yeelirrie uranium deposit has been achieved by adapting the existing HyLogger™/HyChips™ analytical technique to measure resource assay pulps. Spectral analysis via HyLogger™ and HyChips™ systems has previously been used as a small-scale geometallurgical research tool, but never before has it been quantitatively applied to an entire resource sample population for the purpose of developing stand alone block models for major clay minerals. Economic uranium mineralisation within the thin but extensive Yeelirrie?palaeochannel?primarily exists within the transition zone between a groundwater-derived calcrete and the underlying clay-quartz regolith. Early geometallurgical investigations identified that certain clay minerals could be deleterious to the efficiency of the uranium recovery process. Accurate calculation of clay mineralogy from resource assays proved too difficult due to chemical similarities between co-existing kaolinite, smectite and magnesium carbonate minerals. A relatively low-cost, efficient and accurate method of quantitative clay mineral analysis was required to measure over 70 000 resource assay pulps. After initial testing and comparison with QXRD, the HyChips™ 3-1 spectral logging system was implemented as a primary method of clay mineral analysis for the Yeelirrie uranium deposit. The resultant spatial data set allowed the interpretation and geostatistical analysis of geometallurgical domains across the deposit. Clay block models were generated and used in geometallurgical resource calculations to benefit the mine planning process.

Sep 5, 2011

I was delighted to be invited to be patron of this Joint Conference, but the challenging task you have set yourselves, and your speakers' depth of expertise, deny anyone, even the patron, the opportunity to be patronizing. Australia's history has been inextricably link- ed with the fortunes of our great mining industry. That link will remain. Just as the gold rushes of the last century, and the discoveries at Kalgoorlie and Broken Hill changed the lives of generations, so the more recent development activity in iron ore, bauxite, nickel, coal, and uranium are having a significant impact on the lives of Australians today. The minerals industry has contributed to Aust- ralia's jobs and prosperity. Mining is not free of problems, but so long as safeguards are strong and appropriate the net benefits the mining in- dustry brings Australia will continue to be enor- mous. We rely on our mining industry to find, prove, develop and sell our minerals profitably, and my Government is committed to maintaining a healthy mining industry.

Jan 1, 1978

By S J. Tear, L D. Queen

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Frieda River Project is located in the north-west of Papua New Guinea. The target commodities for a bulk mining operation are copper and gold associated with a large felsic porphyry system. The project comprises a series of deposits, with the Horse-Ivaal-Trukai (HIT) being the largest. It also includes the adjacent smaller Koki and Ekwai deposits.Previous resource estimates for the HIT were made using 14 separate mineralised domains based on structure, copper grades, lithology and alteration. H&S Consultants (H&SC) has revisited the deposit and concluded that a simpler methodology could be used for resource estimation without using wireframes as hard domain boundaries. This conclusion is based on reviewing all the available geological data combined with geological and resource experience of porphyry deposits.It is generally acknowledged that porphyry deposits form by diffusion of mineralising fluids through the host lithologies, meaning that sharp boundaries are unlikely unless these fluids encounter specific physical or chemical boundaries. It is important to prepare a comprehensive geological model prior to attempting resource estimation as it forms the framework for the estimates; however, not all geological features may be relevant to the distribution of mineralisation and there can be a tendency to overcomplicate the estimation process by using too many domains. Unless a hard boundary can be identified consistently and unequivocally, it is generally better not to use a boundary in that location.H&SC completed unconstrained models with no top-cutting using both a simple flat search ellipse and a steep search ellipse to generate global resource estimates reported within a predetermined pit shell at a 0.2 per cent copper cut-off. Both outcomes are within 10 per cent for the tonnes, contained copper tonnes and gold ounces compared to the constrained resource estimate. The slight differences are most likely due to the different search strategies, but also indicate the robustness of the unconstrained modelling approach.CITATION:Queen, L D and Tear, S J, 2015. The Frieda kiss – keeping it simple , in Proceedings PACRIM 2015 Congress, pp 361–368 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Renwick MT

Two innovative ground reinforcement products have been developed for use in the mining industry. One of these products is a high strength polyethylene (HOPE) bar for use as a rib bolt in underground coal mining and as a corrosion proof tendon in open pit mines. The other product is a cable bolt (Ultrastrand) which demonstrates enhanced load transfer and is available in continuous lengths. Ultrastrand's exceptional in- situ performance and versatility makes it ideal for mechanised installation in both underground and surface mining operations. Details of these products are presented and results from labortaory and field trials are discussed.

Jan 1, 1992

By Smele J. S, Dawes W. D

In recent years there has been a trend among mining companies to diversify exploration and development away from the countries that have dominated mining activity for the latter half of this century. With some exceptions, this trend is accelerating and is a function of the recognition that many parts of the world, with no previous exposure to modern exploration, are endowed with considerable mineral potential. In addition coincident with changing political and economic circumstances, many countries have recognised the benefits of attracting international mining investment and have radically changed policies, fiscal and legal regimes so as to encourage exploration and mining. Some countries, however, have not readily accepted mining for cultural or social reasons and have yet to make effective changes to mining legislation. For historical reasons, other countries may have little or no direct experience of western economics, nor may they fully recognise the need for stability and competitive fiscal and legal systems to attract foreign investment. Not all ventures in new countries have been commercial successes and there have been some lamentable and recent lapses from grace. Company strategies, company standards and management objectives can also vary widely from company to company. What may be an acceptable risk or rate of return for one may be completely

Jan 1, 1997

By K Williams, M Pender, T Honeyands, T Krull, D McCallum, R Holmes, R Orense

Bulk cargoes, including iron ore fines, must be shipped according to the rules agreed by the member states of the International Maritime Organization (IMO). One critical safety measure is the transportable moisture limit (T?ML) required for Group A cargoes (cargoes that may liquefy). A number of shipping incidents involving iron ore fines from India, where liquefaction of the cargo was suspected to be the cause, have brought the issue of iron ore fines T?ML into the spotlight. Extensive research has been undertaken by the major iron ore producers from Australia and Brazil to support the IMO in developing regulations for the shipment of iron ore fines. To this end, iron ore companies sponsored the AMIRA P1097 project to establish a modified T?ML test approach specific to iron ore fines. The project was undertaken by TUNRA Bulk Solids, CSIRO’s Centre for Bulk Solids and Particulate Technology and the University of Auckland, with project leadership provided by Creative Process Innovation. This program of work supported test work findings from the IMO Iron Ore Technical Working Group, which reported its findings in September 2013.The purpose of this paper is to present the major research findings from the AMIRA P1097 project, which includes a review of the original T?ML methods, highlights of the research that supported the new iron ore fines T?ML method and an outline of current iron ore T?ML requirements.CITATION:Williams, K, Honeyands, T, Holmes, R, Orense, R, Roberts, A, Pender, M, McCallum, D and Krull, T, 2015. Maritime bulk cargo transportable moisture limit requirements for iron ore shipments, in Proceedings Iron Ore 2015, pp 399–410 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

There are serious problems in forecast- ing accurately and achieving this goal depends on good quality information, correct assumpt- ions and sound analysis. planner. The forecaster must focus attention on a number of key areas of interest. These areas include major economic trends and changing GNP structure, consumption time series, end-use consumption patterns and substitution potential, accurately updating data bases (up to 5 years ahead), random factor estimation and examination of both long term and secondary mine potential. While metal price forecasting has suffered due to recent uncertainties, with increased importance on planning tools and cost analyses, it is still a necessary function. Forecasting is subject to the real world and the metal industry is made up of imperfect markets in a dynamic state. The real world provides the challenge to improve the accuracy of forecasting.

Jan 1, 1983

By Gostylla W

The economic feasibility of controlled district cross-cut recirculation is examined in this paper with particular reference to the most important mine ventilation network parameters. An algorithm is developed to express the annual cost of recirculation which is then compared to the annual cost of conventional ventilation using the University of Queensland Experimental Mine as a case study. The concepts of resistance ratio and volumetric efficiency ratio are introduced and used to analyse the economic feasibility of controlled recirculation within a mine ventilation network.

Jan 1, 1988

The development of the Australasian Code for Reporting of Identified Mineral Resources and Ore Reserves is a significan step towards informing the financial community and the public about the future profitability and risks of investing in resource companies. The Code is also important from the accountants' point of view because it provides them with a well-defined bash for assigning costs or attributing value to the assets of resource companies and hence improving their financial reports. Although reporting to the public is ultimately the responsibility of management, accountants, like geologists, are frequently required to provide information for inclusion in these reports. Jr the last ten years, there has been a considerable refinement in the reporting of mineral resources which can be attributed mainly tc the progress made towards developing the Code. It seems tha the classification and terminology that the geologists have developed are widely used in the annual reports. However, little progress has been made by accountants in improving the financia information. The purpose of this paper is twofold: (a) to outline briefl) some of the major problems in accounting and reporting fo; mining companies and; (b) to examine the potential contribution of the Code in solving those problems.

Jan 1, 1990

By C Young

In the vast expanse of Western Australia’s mining sector, a critical issue has come to light: many mining operations overlook the power of a Broad-Brush Risk Assessment (BBRA) to uncover their critical risks. This oversight has led to a cascade of challenges, where some mining endeavours find themselves grappling with: - Unidentified and unmanaged fatal risks, casting a shadow of uncertainty and heightened compliance risks. - A bewildering landscape where the concept of critical risks remains enigmatic, with some mistaking the risk register for the BBRA. - A fog of confusion surrounding the guardianship of these critical risks, leaving safety responsibilities blurred and undefined. Yet, the solution lies within our grasp. An effective BBRA empowers organisations to: - Pinpoint with unwavering certainty every ‘true’ critical risk. - Clarify ownership for each critical risk, ensuring accountability and swift action. - Create a prioritised roster of critical risks, illuminating the path to safer operations. - Lay the foundation for essential follow-up actions like bow-tie analysis, the identification of critical controls, and the fortification of the safety and health management system. Join us in this presentation, where we delve into the heart of an industry-leading BBRA process. Discover practical insights that will enable your organisation to craft and implement BBRA strategies, bridging the gaps in your journey toward preventing fatalities and fortifying safety protocols.

Apr 16, 2024

By B Lumsden, R Smiles

Independence Group’s Jaguar Mine treats a polymetallic ore producing a copper concentrate and zinc concentrate. Effective separation of the sulfides requires relatively fine grinding with flotation feed P80 of about 75µm. Zn losses to final tails are greater than 60 per cent and <32 µm. When magnetic conditioning was first installed in 2010 it showed about an 8 per cent reduction of zinc in final tail and on some ores a similar benefit for silver as well. Current testwork is showing about a 12 per cent reduction in zinc and silver in final tail, consistent with the original testwork. Sizing of the final tail during the tests showed that the reduction of zinc and silver losses were only in the <32 µm fraction, as would be expected from an aggregation process. However, the most surprising result was about a 4 per cent reduction in zinc and silver in the plant feed with a >99 per cent statistical certainty. The reduction in zinc and silver in the feed is also only in the <32 µm fraction. Therefore, because the magnetic conditioning of Zn flotation feed cannot impact plant ore feed grade the hypothesis is that the magnetic conditioning is reducing the fine mineral from downstream processes, like filtering and thickening, returning to the plant feed in the recycled process water. This hypothesis is consistent with plant observation of dirty concentrate thickener overflow and measurements of solids in the overflow, as well as the average % Zn grade in cyclone overflow that correlates with the magnetic conditioning ON and OFF days. This paper presents these plant test results.CITATION:Smiles, R and Lumsden, B, 2018. Improving fine sulfide mineral recovery in Independence Group’s Jaguar Mine zinc circuit, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 433–440 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By Paine GG

The Kidston Gold Mine commenced mining in 1984 and current annual production is 12 million tonnes, increasing in 1990 to 18 million tonnes. Mill throughout per year is 4 million tonnes with the balance of material being waste. The operation is a conventional hard rock open pit truck and shovel operation mining 12 metre benches. Buffer blasting is utilized to minimize post blast movement of the broken rock to maintain grade control.

Jan 1, 1988

By B J. Beven, A Vatandoost, J Young, S Campbell-Hardwick

The intrinsic value of iron ore depends on its physical and chemical characteristics. For example, silica and alumina are unwanted elements, downgrading iron grade and adversely affecting high temperature processing, attracting penalties in smelter contracts. For this reason, an informed knowledge of processing characteristics and product quality of the ore is valuable and cost effective during mine planning and processing.Ore variability is a significant factor that affects metallurgical behaviour and efficiency of ore processing equipment. Ore of sufficient chemical and physical quality needs to be modelled, mined, processed and usually blended. Feed and product assays are commonly used to assess potential ore upgradability. However, assays alone cannot be all informative of actual processing response given the variability of the physical properties of the ore.This study investigates the potential benefit of implementing a geometallurgical approach during the commissioning stage of the Kings deposit, part of the Solomon Iron Ore project in Western Australia. Kings drill hole database information, ie geological, textural and geochemical data, together with the results of metallurgical test work were used for geometallurgical analysis and modelling. Three main ore types were identified at Kings, namely channel iron deposit (CID), bedded iron deposits (BID) and Detrital Iron Deposit (DID). Additional classifications were utilised to better characterise these units in terms of their physical properties.Bulk sampling for each ore type was carried out across the deposit for metallurgical testing. Multivariate statistical models were developed for prediction of product quality for each geometallurgical unit. A new approach for modelling yield based on ore upgrade factors is introduced. These models were then applied to the Kings regularised mining model to assess product quality across the mining blocks and to plan product stockpiling and blending strategies.CITATION:Vatandoost, A, Beven, B J, Campbell-Hardwick, S and Young, J, 2013. A geometallurgical approach for iron ore product evaluation, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 259-266 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

Blasting, particularly bench blasting, uses finite length cylinders of explosive close to two free faces. The rock to be blasted is usually intersected by a complex 3-D system of joints. To fully simulate a blast, a 3-D dynamic model is required. It is shown that the static stress distribution around a long cylinder can be reproduced by superposing the static stress distribution of a suitable chain of spheres. Thus, the dynamic results for individual spheres given by Favreau (1969) can now be substituted for the static results to give a dynamic model of the stress distribution around a long cylinder. Comparison of measured and computed waveforms show that the measured waveforms are much more attenuated and dispersed than expected. The consequences for explosive evaluation and design are Discussed.

Jan 1, 1990

By A Audétat, W T. Li

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Middle and Lower Yangtze River metallogenic belt is one of the most important polymetallic resource areas in China. Iron oxide-apatite deposits, mainly distributed in Ningwu and Luzong volcanic basins, are a distinct type of iron deposits in this region. These deposits have a close temporal and spatial relationship with Mesozoic dioritic porphyries and are characterised by magnetite-apatite-pyroxene/actinolite ± anhydrite assemblage and large-scale sodic-calcic alteration.Widespread multiphase inclusions in pre- to main-mineralisation stage pyroxene and garnet in Meishan (in the Ningwu basin), Luohe and Nihe (both in the Luzong basin) iron deposits were trapped at ~780°C in extremely saline brines (~90 wt per cent NaCl equivalent), consisting of Na (13–24 wt per cent), K (7–11 wt per cent), Ca (~7 wt per cent), Fe (~2 wt per cent), Cl (19–47 wt per cent) and SO4 (3–39 wt per cent), based on petrologic, microthermometric, Raman spectroscopic studies and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses of natural fluid inclusions and synthetic analogues. The high Cl/Br, Na/B and S/B ratios in brine inclusions and the heavy sulfur isotopic values of anhydrite and pyrite (d34SAnh = +15.2 to +16.9‰, d34SPy = +4.6 to +12.1‰) suggest a significant contribution from both halite- and anhydrite-bearing sedimentary rocks. The involvement of evaporites caused the production of large amounts of high-salinity brines with apparently enhanced capacity to extract iron from the dioritic intrusions.According to their geologic features and the above characteristics, these iron oxide-apatite deposits are considered to be a special type of iron oxide copper gold (IOCG) deposits characterised by high contents of Na, Ca, Cl and SO4 in the ore-forming fluids. Moreover, we believe that evaporite-bearing sedimentary basins are more prospective than evaporite-free ones for these kinds of deposits.CITATION:Li, W T, Audétat, A and Zhang, J, 2015. The connection between evaporites and iron oxide-apatite deposits, Yangtze River, China – laser ablation inductively coupled plasma mass spectrometry analysis of Na, S, Cl and Br in fluid inclusions, in Proceedings PACRIM 2015 Congress, pp 623–630 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Most text books on rock blasting claim that the relationship between burden and borehole diameter is linear. The statistical calculation presented here with real values from one hundred open pit and underground mines indicates that the relationship is exponential. For underground mines the burdens are consistently lower than those for open pit mines because of higher ore densities, greater confinement in blasting, and finally greater demand for well fragmented rock. The results shown in this paper are recommended to be considered in basic teaching of rock blasting technique. The formulas can be used for a first rough estimation of practical burden and spacing. The formulas do not however give any information about the fragmentation. For that purpose it is necessary to use other formulas not described in this paper.

Jan 1, 1990