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X-ray analysis of polycrystalline powder samples has grown beyond its roots in the world of laboratory research and is now regarded as one of the most powerful industrial process-control tools in the field of building materials. This is the key to characterise the element and crystalline phase composition of the material. This is due largely to the development of industrial X-ray analytical systems such as PANalyticalÆs twin solution, which has transformed the advanced analytical techniques born in the laboratory into a robust, workmanlike and easy-to-use tool for todayÆs heavy industries. The increasing use of alternative fuels makes the Bogue method less reliable. Therefore, the real phase quantification by the Rietveld method is the only choice. Additional fine-tuning of the Rietveld method by using alternative methods guarantees the most accurate quantitative results. Moreover, the recent development of ultra high-speed X-ray detectors allows for æon the flyÆ quantitative X-ray diffraction analysis and a truly interactive process and quality control.

Jan 1, 2008

By Svenson D

Most exploratory drilling in the N.S.W. coal fields has been conducted using convent- ional diamond drill rigs of modern design, us- ually truck or trailer mounted. Conventional diamond drill rigs have also been used exten- sively by the Queensland Department of Mines for coal exploration. However almost all of the exploratory drilling of surface mine coal prospects throughout Queensland has been conducted using rotary rigs typified by the Mayhew 1000 truck mounted unit. The rotary rig has proved capable of both rapid non-core drilling and core drilling with high core recoveries when modern core barrels have been used by experienced drillers. For deep or continuous core drilling, wire-line equipment is now in general use. Both wire-line and conventional coring is effected using stationary split inner tube barrels, for minimum core disturbance, maximum core recovery, ease and accuracy of logging and sub-sectional sampling. Diamond core bits are generally required in N.S.W., with water circu- lation. In Queensland, the generally softer coal measures strata can be successfully cored using tungsten carbide bits and air circulation is the preferred method where possible.

Jan 1, 1977

High sulphur volcanic-hosted hydrothermal environments are favourable geological environments for gold mineralisation. Numerous world-class gold deposits including Pueblo Viejo (Dominican Republic), Goldfield (Nevada), EI Indio (Chile), and Wa

Jan 1, 1994

The theme of the conference this year is diversification. One way to diversify is through acquisition. The principle underlying the winner's curse is that in competitive bidding situations where the value of the asset bid for is uncertain the winning bid will overstate the true value of the asset. The successful bidder is blessed with the winner's curse. What this paper will explore is to what extent this is true; how acquirers can avoid being blessed with the winners curse; and show how joint venture deal structures are used within the mining industry to avoid the winners curse.

Jan 1, 1996

By Mike Sharwood

This subject is to be discussed in greater depth by Mike Sharwood. It has also been the subject of a mini-symposium by the Melbourne Branch of the AusIMM in October, 1993. The papers from this symposium were distributed to the membership late last year "to raise their consciousness and to promote greater awareness and understanding of the wide range of liabilities that may arise". An introductory paper by Nicholson outlined the many areas in which liability may arise with particular emphasis on expert reports, eg: Takeovers Schemes of arrangement Acquisitions from associates Prospectuses Related party transactions Directors' duties Continuous disclosure Other influences (environmental, occupational health and safety, trade practices)

Jan 1, 1994

By Wharton C. L

This paper describes a new computer program which can significantly increase the Net Present Value of either an open cut or underground mine by optimising the cut-offs used during the operating life of the mine. It was developed over a period of about three years by Whittle Programming Pty Ltd of Melbourne, Australia. Several authors have contributed to the theory behind this work, but the ideas were further developed, consolidated, and clearly explained by Lane (1988). It was this book that triggered the development of the new program. The paper starts with an explanation of the theory behind this type of optimisation, and then goes on to describe the computer methods used to optimise the different parts of the problem.

Jan 1, 1995

The late 1960's and 1970's saw the initial development of the coal resources of the Bowen Basin of Queensland. The projects developed relied on large scale, open-cut operations using draglines for overburden removal and, in the majority of cases, project viability could be established based solely on those open-cut operations. Many of the mines developed in the 1980's have the same characteristics.Unlike these mines, the German Creek Mine has limited open-cut reserves at low overburden to coal ratios, and planning of the complex involved a large open-cut mine capable of developing early cash flow, with phased introduction of underground mining to replace open-cut capacity as the strip ratio increased.

Jan 1, 1985

By T Peglas, A de Aboitiz

The Queensland Government, via the special purpose company vehicle û City North Infrastructure Pty Ltd û is currently developing BrisbaneÆs Airport Link underground toll road and Northern Busway (Windsor to Kedron).Airport Link is a predominantly underground toll road planned between BrisbaneÆs northern suburbs, the airport and the Brisbane Central Business District (CBD) frame. The Northern Busway forms part of BrisbaneÆs expanding busway network, sections of which will be jointly delivered with Airport Link. Airport Link will connect the North-South Bypass Tunnel, Inner City Bypass and local road network at Bowen Hills to the northern arterials of Gympie Road and Stafford Road at Kedron and Sandgate Road and the East-West Arterial in the cityÆs north-east. The Northern Busway is a two-lane, two-way bus-only roadway proposed to connect the existing Inner Northern Busway at Herston with Windsor, Lutwyche, Kedron, Chermside, Aspley and Bracken Ridge. Airport Link and Northern Busway (Windsor to Kedron) is one of the largest infrastructure projects planned in the first phase of the State GovernmentÆs South East Queensland Infrastructure Plan and Program. The paper will provide an overview of the projects, including a discussion on the technical and environmental aspects as well as the procurement of the Airport Link as a public private partnership.

Jan 1, 2008

By I D. Hair

A numerical groundwater model was used to predict the nature of interactions between heavy mineral sands mining operations and the groundwater regime at North Stradbroke Island, Southeast Queensland. North Stradbroke Island is formed mainly of massive vegetated Cainozoic aged dune sands. Since the 1950s, a number of operations have mined rutile, zircon and ilmenite on North Stradbroke Island. In such mining operations, a dredge and an associated processing plant are floated in a pond either above or below the prime groundwater table The numerical model was based on the North Stradbroke Island Groundwater Management Model, developed in 2001 by the Department of Natural Resources and Mines (NR&M). This model was constructed using the modular, cell-centred, finite-difference groundwater flow model, MODFLOW, developed by the United States Geological Survey (USGS). The NR&M model was refined to improve model resolution and detail for simulating dredge mine paths. Of particular interest were: water table fluctuations induced by mining for the identification of slope stability risk; the optimisation of sand spear arrays supplying mine make-up water requirements; inflow and outflow rates to the dredge pond for overall mine water balance; and interactions with Eighteen Mile Swamp and water supply bores controlled by the Redland Shire Council (RSC). Depending on the water level in the dredge pond compared with the surrounding groundwater table, water either flows out of the dredge pond into the groundwater regime or from the groundwater system into the dredge pond. The MODFLOW river package (RIV) was utilised for the modelling study. Dredge pond movement was simulated using specialised software developed by Watermark Numerical Computing (WNC) to interpolate pond positions and map the dredge path to the model grid both spatially and temporally. As tailings placement affects the groundwater system through increased recharge, the MODFLOW recharge package (RCH) was utilised to simulate different recharge efficiencies. Long-term model predictions were made for the period from July 2002 to May 2021. Results of the modelling showed that exchanges of flow between mining operations and the groundwater regime could be effectively managed. The study provided valuable information which was used to develop an appropriate mine water management plan.

Jan 1, 2003

By A M. Robertson, R Lefebvre

Air movement and associated oxygen transport through waste rock dumps has the potential to significantly enhance the rate of oxidation of pyrite-bearing material. While this is a desired outcome for most heap leach operations, airflow in waste rock storage facilities can result in significant increases in generation and acceleration of acid rock drainage. Hence, a good understanding of internal airflow through waste rock dumps is required to control ARD and minimise any associated liability. The principal mechanisms contributing to airflow and oxygen transport in a waste rock pile include: diffusion; advection due to a thermal gradient (chimney effect) and/or wind pressure gradients; and advection due to barometric pumping. While diffusion is typically limited to a near-surface zone of a few meters depth, advection and barometric pumping have the potential to move air (and oxygen) to much greater depths into the pile. In general, the more permeable the waste rock material, and the greater the height-to-width ratio of the waste rock pile, the greater is the potential for advective air movement. The reactivity of the waste rock material as well as the coarseness (hence air permeability), and the spatial variability of these properties within a pile, have a strong influence on the magnitude of thermally induced advection. In contrast, air movement due to barometric pumping is controlled by the waste rock porosity, changes in ambient air pressure and the heterogeneity of air permeability of the waste rock dump. Results of field monitoring and numerical modelling using TOUGH AMD are presented to illustrate the concepts on air movement in waste rock piles discussed in this paper. During the design and construction phase, airflow can be controlled by judicious placement of reactive waste rock and use of selective placement techniques to control the internal structure of the waste rock facility (eg introduction of horizontal layering, prevention of inclined, high-permeability, channels (æchimneysÆ)). Several closure measures are available to minimise airflow including: placement of a low-permeability cover to reduce air entry; and placement of a non-reactive cover material to isolate reactive material from the zone of active airflow and/or regrading of the waste rock pile to obtain a geometry and internal structure less susceptible to advective airflow.

Jan 1, 2003

By Fewings JH

When the mining and milling of 1100 Copper Orebody commenced, difficulties were experienced in producing a satisfactory grade of copper concentrate. The major concentrate contaminants were fine pyrite and silica, particularly in the minus 10 microns fraction. Studies of the 1100 Orebody showed that much of the fine grained pyrite and a proportion of the silica present in the ore contained carbonaceous matter in the form of complete or partial rims and as internal carbon films disseminated throughout grains. The hydrophobic surface property of the carbonaceous material resulted in an inherently flotable fine pyrite and silica fraction. The addition of a 60:40 mixture of nigrosine and dextrine, initially to a prefloat concentrate of the inherently flotable carbonaceous material and finally to'the total copper flotation feed, successfully controlled the flotation rates of the carbonaceous pyrite and silica. The objective of a 25 per cent Cu concentrate grade was then achieved without decreasing copper recovery.

Jan 1, 1970

By Linkson PB

The presence of residual cyanide in mine tailings and fill sands may, under specific circumstances, lead to acute and/or chronic cyanide poisoning of the environment and individuals. In this paper, the nature of cyanide contained in mine tailings is discussed, along with the circumstances under which such cyanide would become a hazard. A number of methods for cyanide degradation are reviewed in the paper, with special emphasis being placed on biological degradation (due to its low costs and the non toxic nature of the degradation process itself). Recommendations are made as to the best methods of setting up a biological degradation system, for use in mining Situations.

Jan 1, 1987

By B G. Lottermoser

Field and laboratory data combined with computational modelling have been used to predict the pit water quality for the Highway Reward mine. Open pit mining of the Highway Reward copper-gold deposit has produced a final mining void with a diameter of 600 m and a depth of 280 m. This void will be left to fill with ground and surface water once pumping of pit water ceases. Several leaching tables were constructed to simulate weathering reactions and surface water run-off in the major pit wall units during a 200-day leaching experiment. To date, about three-quarters through the experiment, combined run-off from these cells has reached a pH

Jan 1, 2003

By N Maistry, A Singh

It is estimated that in less than a decade, high-grade iron ore reserves in South Africa will be depleted, leaving only low-grade ores with a dominant lithology of banded iron formation (BIF) hematite. BIF is a complex ore reserve as it is typically liberated below 1 mm, resulting in high energy costs. However, due to its abundance, its beneficiation potential should be evaluated to maximise recovery at an acceptable product grade. To develop a beneficiation program for BIF hematite, the first step is to determine the effect of two laboratory crushing techniques on mineralogical characteristics, specifically liberation and shape. For this study, the cone crusher and high pressure grinding rolls (HPGR) were used. The Electron MicroProbe Analysis (EMPA) and Mineral Liberation Analyser (MLA) were used to compare the mineralogical characteristics. The liberation characteristics for hematite are similar for both crushing techniques; however, HPGR preferentially liberates quartz. HPGR achieved 8– 12 per cent additional quartz liberation in the greater than 80 per cent and 100 per cent liberation classes respectively and specifically in +75 μm size range. Improved quartz liberation is associated with lower energy requirements for downstream milling and improved separation efficiencies for beneficiation units that operate in this size range. Both samples displayed similar shape characteristics; most particles were elongated smooth and the rest were elongated angular. Good hematite liberation is expected at grinds of 212 μm to 150 μm. Further consideration should be given to throughputs, energy efficiency and downstream equipment selection prior to selecting a crushing technique.

Sep 18, 2023

By T Blyth, D Holden, N Archibald, S Huffadi

The Morning Star mine is owned by Hill 50 Gold NL. Gold is hosted in quartz-carbonate ¦stibnite ¦molybdenite veins that occur in a series of deformed, altered and metamorphosed mafic volcanics with subordinate sediments and felsic intrusive rocks. The irregular gold distribution and its relationship to structure and alteration intensity makes the definition of stoping limits difficult. Understanding the structural evolution of the orebodies and the contemporaneous and later structures that affect the orebodies has been very useful in this context. This paper reports on a detailed mapping exercise (as part of a more extensive and on-going investigation) and the integration of this mapping with other geological and grade control data in a 3D modelling environment to provide an expanded basis for stope design. Three types of mineralised zones can be discriminated based on the morphology of the veins within. They are:those associated with strongly folded, thick veins (approximately 1 m thick eg 05 orebody); those comprising planar, boudinaged and some folded veins which consolidate to form tabular, steeply dipping bodies (eg 010 orebody); and zones containing the above vein types and thin, highly deformed veins within zones of intensely foliated country rock that result in localised, irregularly distributed high-grade gold zones (eg 02 orebody). The mineralised zones associated with thick folded veins are typically predictable over many tens of vertical metres. The second and third types of ore zone is generally less predictable. Detailed mapping and structural kinematic studies indicate all ore zone types are affected by progressive deformation involving strong strain partitioning. It is interpreted that high strain zones, recognisable by intense foliation development and highly deformed veins, are the latest stage of a progressive deformation which approximates bulk flattening. Structural controls on mineralisation can be defined at two different scales.Regional scale folding has deformed a sequence of mafic volcanics with interlayered sediments and felsic intrusives. Initial geometry of felsic bodies relative to orientation of the primary lithological layering and the bulk shortening direction is interpreted to be critical for initiation and development of strongly dilatant zones within this package of rocks, and Local scale dilation is evidenced by development of several vein sets whose range in orientations and opposed vergence relationships suggest a pre-folding origin comprising both extensional and hybrid shear-extensional types. Continued deformation resulted in folding of these veins with strong strain partitioning. Major vein packages are closely spatially associated with the felsic/mafic contact and an interpreted early structure which appears to have partitioned early dilation. This structure is now obscured by strong deformation but is currently represented by a zone of planar veins.

Jan 1, 2000

By X Yang

White phosphorus (P4) is a critical element in industry, but its current production from phosphate rock using the carbothermal reduction method raises significant environmental and health concerns. This pressing issue necessitates the development of new technologies that facilitate the sustainable production of P4. In response, my team is actively developing an innovative, coke-free approach for white phosphorus production. This method involves the dissolution of phosphate rock in molten CaCl2, followed by the extraction of P4 through electrochemistry at relatively low temperatures. Moreover, this approach has the potential to utilise phosphate-bearing solid wastes as raw materials, further enhancing its environmental benefits. By employing this cutting-edge technique, we aim to revolutionise the phosphorus chemical industry towards greener and more sustainable practices. This paper provides evidence of the feasibility and effectiveness of our proposed approach.

Aug 21, 2024

By Mousset-Jones P, McPherson M. J

This paper explains and discusses a computer program developed to deter- mine the optimum combination of fan pressures that will give a required distribution of airflows in a mine ven- tilation system. The program is based on an existing simulator, VNETPC and two experimentally developed relationships: (1) linearity between fan pressures and added regulator resistances and (2) a non- linear convex function relating the system air power and the fan operating Pressures.

Jan 1, 1988

By Peck J. P, Kennedy D

Drill performance monitoring studies were recently completed at the Fording River mine, British Columbia. Microprocessor-based instrumen- tation and data analysis techniques were developed with the objective to improve short and long term mine planning. Data analysis permitted the identification of thicknesses and interfaces between soft/hard zones at depth based upon the recorded responses of the drill. Data clearly con- trast the soft coal seams and harder waste rock units based on variations in recorded drill rotary speed and torque, hydraulic downpressure, bail- ing air pressure and instantaneous rate of penetration. These parameters were monitored and recorded at 10 cm sampling intervals. Processed drill data was correlated with gamma logs, an existing means for locating coal seams and distinguishing between waste units. Current development of a pattern recognition module aims towards automated interpretation of drill data, identifying micro-and macro-geological and geomechanical rock mass characteristics. Delay between acquiring, processing and interpret- ing the drill data for practical use by mine personnel should be minimized. Integration of this technology with the mine's current main-frame based Mine Engineering Application System software will enable more accurate and timely annlication of the nrocessed drill data.

Jan 1, 1989

The products required by customers today have become far more complex and consequently more demanding to handle. And thereÆs the dilemma. Nowadays, people tend to stick to a trade for just a few years instead of for a lifetime, and this means that the customerÆs employees cannot be expected to get more than general knowledge of how to handle modern mining and construction equipment. To meet this challenge, major steps are being taken by suppliers to make their æmusclesÆ more user-friendly. Also the supplier is assuming a larger share of responsibility for the product including operators training, supply maintenance services and, in many cases, performance guarantees. In other words, the supplier is today supplying a function or an activity rather than just muscles. Some of the new generation drill rigs have been on the market for a few years and reliable experience has been collected and is addressed in this paper. Some of the information is well supported by figures while others are just statements from users of the rigs.

Jan 1, 2005

A Modelling Approach Using a Back-Calculated Induction Time to Predict Recoveries in Flotation

Sep 13, 2010