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By G. W. Douglas

The need for dimensionally stable filled polymer composites has spurred the quest for materials that possess a negative coefficient of thermal expansion (CTE). Finding minerals and materials with a negative CTE large enough to counteract the substantial CTE found in polymers proves challenging. Much research has been per-formed over the last decade to uncover various materials that possess this unusual behavior. A list of materials that have demonstrated negative properties are discussed, as well as the experimental use of one such material (ZrW2O8), in a polymer matrix composite. Other negative properties, such as negative Poisson?s ratio and negative stiffness, are also examined. Key words: Negative properties, Coefficient of thermal expansion, Zirconium tungstate

Jan 1, 2010

By Martin Williams

During the coming decade, many of the first generation of ‘super-pit’ gold and base metal mining operations in North and Latin America will reach the end of their economic lives. The closure of such pits in a manner which is environmentally sustainable presents a considerable challenge to the minerals industry. Pit closure often results in the partial or total inundation of formerly dewatered mining operations, and the resultant formation of lakes. The development of techniques for predicting, and controlling, the chemistry, groundwater discharge characteristics and long term hydrospheric impact of these lakes has become a critical aspect of pit closure planning. In this sense, the paper point out that Sleeper Mine was the first of a new generation of open pit gold mines developed in Nevada, USA. The closure of the Sleeper pit exemplifies the use of a range of pragmatic approaches to pit flooding, with applicability to mine closure at many other sites throughout the Américas.

Apr 22, 2003

The Tasman Orogenic Zone is regarded as a single metallogenic province (the Tasman Province) with four SUb-provinces corresponding with its major tectonic components: the Lachlan, New England, Hodgkinson.and North Queensland orogenic provinces. Within the Tasman Province there are four main ore-rock associations.These are1. manganese and iron with sedimentary and basic volcanic rocks,2. zinc-lead-copper and copper with intermediate-acid volcanic sequences,3. minor chromium, platinum, and osmiridium with ultramafic complexes, and4. tin, wolfram, gold, and copper with syn- and posttectonic granitic intrusions.Whereas the ores of ultramafic and volcanic associations form geographically-restricted metallogenic districts, the ubiquitous granitic ores may be subdivided into twenty-one districts that cover almost the entireOrogenic Zone. The Tasman Province is notably lacking in uranium ores and Mississippi Valley-type deposits.There is a distinct tendency for ores of each association to be progressively younger to the east and north, thus paralleling the progressive growth and stabilization of the Zone. Similar ore-rock associations are present in repeated phases of mineralization from the Cambrian to the Permian-Triassic, reflecting the essential homogeneity of the Tasman Province, and the similarity of the successive tectonic cycles.

Jan 1, 1972

By Travis A. Davidson, Ralph E. Burnham, Cathy Aimone-Martin, J. Kelly Ratliff

Blasters face a long list of tasks to execute daily—from vehicle inspections to blast design and layout, hole loading and tie-in, securing the site, and finally, safely executing the blast. Good practices and, in most cases, regulations and requirements necessitate documenting their work, specifically their blast report. While some blasters use paper forms, others use electronic means to streamline the process. The authors have served as attorneys and expert witnesses in representing companies and individual blasters in numerous administrative and legal matters in which documentation of the blaster’s work was both critical and detrimental to the effectiveness of defending their work. This paper discusses in a case-study manner the authors' observations concerning good blast report format, specific observations around electronic and paper report completion, record-keeping, seismograph setup and recordkeeping, video and photo documentation, internal auditing, and other topics related to documenting the blast. The paper aims to serve as a discussion guide for blasters to improve their blast record-keeping process, develop better practices that effectively document their work, and allow them to defend their work should a claim arise concerning their operations.

Jan 21, 2025

By Sheng-Hui X

This paper introduces a new coal-based rotary kiln process of DRI production - the CRIMM process, which is developed by Changsha Research Institute of Mining and Metallurgy in the past years. Its main features are the use of composite pellets (in rotary kiln). The process consists of preparation of pellets from iron concentrate and coating of coal on their surfaces. The new process is able to overcome a series of defects of the conventional coal-based rotary kiln processes. A continuous test was conducted using an experiment rotary kiln (-0.6;, x 3 m). TFe of the magnetic iron concentrate used in the test is 67.25 per cent. TFe of the product DRI is 88.54 per cent, MFe is 84.11 per cent, S and P are less than 0.02 per cent. The metallisation ratio of pellet is 95 per cent. The pellet power ratio is less than 0.3 per cent. The utilisation coefficient of rotary kiln is 1.3 t/m'-d. The overall recovery of iron concentrates is 99.7 per cent. Two small industrial plants using the CRIMM process are being set up in China. Their coal consumption can be decreased to 520 kg standard coal per ton DRI respectively.

Jan 1, 1999

By A Nugraha, H Thanasekaran, K Tatetdagat

The Kanowna Belle gold mine is located in the Eastern Goldfields of Western Australia, approximately 18 km north-east of Kalgoorlie. The processing plant is designed to process 2 Mt/y and has the capability to treat both refractory and free milling ore from the Kanowna Belle and Kundana mining operations.The Kanowna Belle ore is refractory with the gold mineralisation occurring mostly as fine-grained inclusions in pyrite or as very fine-grained gold located in pyritic arsenic rich growth zones. The Kanowna Belle refractory process includes flotation, roasting of the flotation concentrate, and calcine leaching to extract the gold from the ore.Mineralogical analysis of feed and tailings streams from the flotation circuit have shown that the gold bearing minerals are well liberated and confirmed they are mainly associated with pyrite. Nearly 40% of the flotation circuit losses are in the -38 µm size fraction. To improve the flotation circuit recovery, the fine particle gold recovery was targeted. A Cavitation Tube column was selected for the site-based pilot test work program. This paper presents data generated from the on-site test work, and the benefits of the Cavitation Tube column to improve fine particle flotation.CITATION:Nugraha, A, Tatetdagat, K and Thanasekaran, H, 2018. Flotation circuit efficiency improvement at Northern Star Resources Limited’s Kanowna Belle gold mine, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 403–412 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By W. N. Hoskins

This report covers the final results of a two-phase contract study conducted between July 1974 and October 1976. A comprehensive summary of the initial phase of the study is included. Phase I of the study involved the investigation and evaluation of all potential candidate underground systems for mining the deeper deposits of oil shale and associated minerals in the Piceance Creek basin of northwestern Colorado. Phase II called for the refinement and the detailed technical and economic analysis of the most promising system, or systems, thus disclosed. Of the several systems initially investigated and evaluated, four showed considerable merit for exploiting the deeper deposits: (1) chamber and pillar mining with spent shale backfill, (2) sublevel stoping with spent shale backfill, (3) sublevel stoping with full subsidence, and (4) block caving mining using LHD's. Final refinement and analysis of these four systems indicated their technical feasibility over at least part of the range of conditions expected in the deeper deposits. Their economic feasibility also was indicated under certain operating and market conditions. A variety of engineering, production, and cost information is provided on each of these systems.

Jan 1, 1976

By M F. Lee

Although the Mt Charlotte gold resource was discovered in 1893, it was only in 1954 that geologists correctly interpreted drill data and defined a large low-grade orebody. The mine has been a large, low-cost and profitable producer since 1962 when bulk mining commenced using cut and fill. From 1968 a combination of long hole open stoping with delayed mass blasting was used. This proved to be an excellent mining method for the large, separate subvertical orebodies. The structured but otherwise good quality rock allowed very large stopes to stand unsupported. Exceptionally large equipment, for its time, was used to efficiently mine, muck and move the ore at low-cost. The mine only just survived severe cost pressures in 1974-76, due to very low gold prices. Better gold prices in 1979 and a need to access deeper ore meant a bold commitment to sink the Cassidy Shaft and refurbish the mine to sustain future profitability. In 1997 the Sam Pearce Decline connected to the underground workings, making it profitable to mine upper level remnant ore. Mining-induced seismicity has been a feature of mining at Mt Charlotte. The main cause has been shearing on structures. A mine-wide seismic system was installed in 1994. Large seismic events have occasionally made management question whether a safe working environment can be maintained. Thorough investigations led to an understanding of the problem and development of procedures to minimise seismicity.

Jan 1, 2000

By Parker JB

The Channar Iron Ore Mining Project (the Project) is a joint venture involving the Hamersley Holdings group (Hamersley) and the China Metallurgical Import and Export Corporation (CMIEC). The Project represents the first new iron ore mine development in Australia since 1971/72 and is the first major overseas mining investment by the People's Republic of China (PRC). The Channar mine is being constructed in the Pilbara region of Western Australia and will operate for more than 20 years supplying the PRC with 200 M tonne of high grade iron ore. The Project is configured to take advantage of Hamersley's existing production and support facilities. The Joint Venturers will invest A$280 million to achieve an initial production rate of 3 M tonne/yr and an additional A$120 million over the next 8 years to achieve full capacity of 10 M tonne/yr. Financing the Project to meet the requirements of both Hamersley and CMIEC, with the dependance of the Project on Hamersley's infrastructure, and in a depressed iron ore market, required an innovative financial structure to be arranged in a limited period. This paper describes both the financial structure and its implementation, and draws a number of conclusions regarding the financing of resource projects.

Jan 1, 1989

By J. Gotor, C. Frias, E. Delgado

The Iberian Pyrite Belt (IPB) is one of the world's largest reserves of primary sulphides containing base metals (Cu, Zn, Pb), precious metals and some special metals such as indium. Estimated resources are over 1,500 million tonnes of volcanogenic massive sulphide ores. From 1980´s Europe lives the decline in its mines mainly motivated by the low price of the metals. One aspect that contributed equally to this was the ecological disaster produced by the discharge of more than seven million tonnes from the tailings dam of Boliden-Apirsa (Aznalcollar) in 1998. Today the situation is different; the companies present in the IPB have given evidence that it is possible to reconcile mining projects and care on the environment, and the regional authorities are opening a public tender to re-start Aznalcollar mine. A new challenging era has been started at this Spanish/Portuguese mining area. This paper presents the results and preliminary economics of a project devoted to IPB primary sulphides processing through different technology approach, e.g. conventional selective flotation against bulk flotation or mixed metals flotation combined with hydrometallurgical processing.

Jan 1, 2014

By Sam S. Taylor

[The discovery of many oil fields in Illinois since 1936, and their rapid development have brought the problem of brine disposal to the foreground in that State. The ultimate magnitude of the problem is not yet known, but already it is treat enough to warrant technical investigation. The Bureau of Mines, therefore, has made a general survey of the methods of handling oil-field b brines in Illinois rend has studied in detail three subsurface disposal systems.]

Jan 1, 1940

The U.S. Bureau of Mines has been concerned for many years with the general problems of underground coal mining and the particular problems due to the methane content of the coal. The Bureau and others have worked diligently to improve the health and safety conditions for underground coal miners. It has been recognized for many years that the methane in coal would have some value if it could he recovered and used, Also its removal before coal mining began or during the mining cycle itself would make mining safer and more economic due to a potential saving in ventilation costs. The work covered in this report was carried out to review methods of removing methane from active and inactive regions of operating coal mines and to determine how the methane could be concentrated and utilized economically.

Jan 1, 1975

By Lewis PJ, Halfpenny R, Craighead GA

Exploration drilling by Joint Venture partners CRA Exploration Pty Ltd and Elders Mining PNG Pty Ltd has discovered a signif- icant copper and gold deposit at the Wafi River prospect, 60km WSW of Lae in Papua New Guinea. An indicated resource of 18Mt at 2.5g/t Au using a lg/t cutoff has been delineated in Zone A. No estimate has been determined for the separate copper occurr- ence at Rafferty's Zone but the copper will be significant to the project. Metallurgical studies on the gold indicate that the primary ore is refractory to direct cyanidation giving a highly variable and inadequate response. All conventional refractory ore oxidation techniques perform well on both ore and pyrite concentrate and oxidation occurs rapidly. No metallurgical studies on the copper mineralisation have been undertaken. Hypogene covellite and chalcocite copper mineralisation is associated with an intensely quartz-stockworked, and quartz and alunite-altered intrusive. Economically significant gold mineralisation occurs in distal subhorizontal lenses, within a sedimentary host, that plunge toward the intrusive. These lenses are sandwiched between overlying quartz and alunite-altered zones and underlying quartz and smectite zones in a mixed zone of quartz, dickite, kaolinite and illite alteration. The alteration and mineralisation is classified as a high sulphidation, epithermal style resulting from the influx of hot, acid magmatic fluids. Preliminary land ownership, road access, power supply and mine infrastructure studies are in progress. The project is currently at an advanced exploration stage.

Jan 1, 1991

By John E. Kelley

The Bureau of Mines conducted a study to determine the feasibility of joining refractory metal compounds to each other and to oxide ceramics by a vacuum hot press-diffusion bonding method. Very satisfactory joins were made of ZrC to ZrB2, ZrN to ZrB2, ZrC to ZrN, and of ZrC, ZrN, and ZrB2 to Al203. Each of these join assemblies contained a mixture layer comprising 50 weight-percent each of the two end compounds. The mixture layer, sandwiched between each end compound, enhanced bonding and smoothed out the thermal expansion gradient between the two end members. Strength and thermal shock tests showed that the join areas of the ZrC, ZrN, and ZrB2 joins were stronger and more shock resistant than the parent materials. Also included in the joining tests was one each of TiC to TiB2, TiC to TiN, TiB2 to TIN, and TiC to ZrB2 joins. Each of these was well bonded, showing that the vacuum-hot-press method can be used for a variety of systems.

Jan 1, 1969

By R L. Brathwaite

The gold-scheelite-quartz lodes of the Wakamarina valley were the most productive of the mesothermal gold-bearing areas in the Marlborough Schist. Most of the production came from the Empire City and Golden Bar mines which worked the Golden Bar lode. Only 134 m of its 1800 m strike length are accessible, in the No.2 level of the Golden Bar Mine. A fault has downthrown the Golden Bar Mine section by = 47 m and displaced it left-laterally by 18 m. The lode is a typical ribbon-banded mesothermal vein, averaging c. 1.75 m wide, and enclosing narrow horses of schist country rock. It is composed of bands of milky æbuckÆ quartz with thin laminae of schist. Scheelite occurs in short strings of grains within quartz on the footwall side of the lode and also in small quartz-carbonate veinlets in the foot wall and hanging wall schist. The lode quartz contains only localised traces of pyrite and arsenopyrite. They are more abundant in the wall-rock schist.   The Golden Bar lode lies within a steeply dipping normal fault, which, on its footwall side, is adjacent to a 40 m-wide, shallow-dipping mylonite shear zone. Within 1 m of the lode, the shear foliation has been dragged down to nearly parallel the lode footwall. Wall rock alteration is manifested by a marked increase in K and Rb, which correlate with abundant illite/muscovite and K-feldspar within 2 m of the footwall of the lode. Amphibole, stilpnomelane, and pumpellyite show a progressive decrease towards the lode. As and Sb increase close to the lode, but are at background levels within the lode itself. Enhanced Cr (150-430 ppm) in the quartz, relative to the schists (~40 ppm), suggests that the source hydrothermal fluids passed through and leached mafic rocks, such as the metabasites from the hanging wall of the lode (~400 ppm Cr).

Jan 1, 1995

By I Basson, J A. Miller, M Becker, F C. de Beer, L C. Bam

"Geometallurgy brings together geologists, mine planners and process engineers to extract meaningful mineralogical and textural information from an orebody, with a view to predicting its metallurgical response. Preferably, automated analytical techniques, which provide mineralogical and textural information, should process a large number of samples quickly, relatively inexpensively and reliably. Microfocus X-ray computed tomography (µXCT) is capable of producing 3D volumetric information on texture and mineralogy that satisfies some of these criteria. µXCT has been used extensively to study the porosity and internal pore structure of iron ore pellets as part of downstream processing. It has not been widely applied to earlier mineralogical and textural analysis of unprocessed ore, due to the limited ability of X-rays to penetrate high-density samples. In this contribution, we propose scanning methods to overcome this limitation, thereby facilitating a broader application of µXCT to iron ore resource management.CITATION:Bam, L C, Miller, J A, Becker, M, De Beer, F C and Basson, I, 2016. X-ray Computed Tomography – Determination of Rapid Scanning Parameters for Geometallurgical Analysis of Iron Ore, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 209–220 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By Eulogio Velasco, Jose Nino, Marcos Cardoso

"Recycling of aluminum scrap for production of secondary alloys used for automotive applications is increasing continuously. Automotive alloys require a strict control to remove alloy impurities, inclusions and excess of magnesium. The advantage of aluminum is its recyclability with large energy and emission savings with minimal loss in material properties. The aim of this work is to study the magnesium removal from recycled aluminum by chlorine injection in a reverberatory furnace, and removal by an oxidation process at high temperature in an industrial rotary furnace.The magnesium removal by gas injection is carried out by the reaction between chlorine and magnesium, with its efficiency associated to kinetic factors. In the rotary rapid oxidation of aluminum and magnesium elements at high temperature is characterized by the formation of surface films composed of magnesium oxide. Additionally this work reviews the benefits of an efficient demagging process.IntroductionThe advantages of using light alloys for automotive applications include fuel economy improvement, greenhouse gas reductions and polluting emissions. These characteristics makes the aluminum alloys an attractive option for automotive components such as powertrain products and other critical parts like cylinder heads and blocks. [1]Aluminum alloys coming from recycled automotive components, used beverage cans (UBC) and wrought alloys have positive effects in the energy savings and current environmental trends. Producing a scrap recycled aluminum ingot consumes approximately 5% of the energy required to produce a primary aluminum ingot from bauxite ore. [2]"

Jan 1, 2011

For a large scale open pit mining and concentrating operation, on a low-grade disseminated ore body, it is possible to set an approximate lower bound on economically feasible operating scales and an approximate upper bound on economically desirable scales in a relatively straight forward manner. The optimum scale ofplanned operations, with respect to the objective ofmaximisation ofthe net value ofthe orebody, will have to be arrived at by iterative planning runs, but it may be expected to lie close to this upper bound. The effects of infrastructural costs and of the addition of a risk premium to the cost of capital, to form the discount rate for planning purposes, are considered theoretically and by worked example. It is concluded that a perceived special, unsystematic, risk should not be accounted for by the use of such a risk premium as this is inducive to placing a greater amount of investment capital at risk, for no greater return-rate to investment.

Jan 1, 1986

By Jacek Paraszczak

For mining companies facing strong international competition and unfavorable commodities? prices, automation of underground operations has got a potential to increase productivity and help cut cost. However, despite considerable technological progress in this field, there still remain some problems to overcome. Furthermore, a success implementation of automation depends also on numerous operational, organizational and even human factors. In this context, this paper reviews briefly a technological progress with regard to different underground operations. Following that, several issues related to implementation of automated equipment and systems are presented and discussed. Particular emphasis is put on the factors whose importance is sometimes underestimated. Some recommendations in this respect are also given. It is stated that a success of an automation project is a function of many ?winning conditions?, which may be created through a very thorough planning and preparation. It is also underlined that despite achievements made, a vision of a man-less underground mine is not yet a question of near future as it may seem.

May 1, 2001

By D. Nyungu

Despite observations of spalling and damage of mine excavation wall rock in the Bushveld Complex (BC) over the passage of time, there have been very few time-dependent or creep tests carried out in South Africa on rock, particularly on BC rock types. The research described in this paper deals with the investigation of stress and strain conditions influencing spalling of wall rock in BC mine excavations, and the influence of time on the tensile strength of several BC rock types. Time-dependent laboratory testing of BC rocks was carried out in indirect tension. The results show that the magnitude of the tensile strength of BC rock types is approximately 5% of their uniaxial compressive strength magnitudes. The average long-term uniaxial compressive strength of the BC rocks, interpreted from the axial stress-volumetric strain graphs, is 56% of the UCS value. The long-term tensile strength is shown to be less than 70% of the normal tensile strength. Extension strains at tensile strength failure ranged between 0.16 and 0.21 millistrain. Values corresponding with the long-term tensile strength are less than 70% of this range, namely, 0.11 to 0.15 millistrain. These results represent new knowledge, since such rock testing and analysis does not appear to have been carried out previously on BC rock types. Elastic numerical modelling was carried out to illustrate the extents of tensile stress zones and extension zones around of typical BC mine excavations. The models showed that large zones of extension strain can occur around BC excavations, and that the magnitudes of the extension strain can substantially exceed the critical values determined from the laboratory testing. The implication of this is that there are substantial zones surrounding BC mine excavations that will be prone to time-dependent spalling conditions and perhaps more significant failure.

Jan 1, 2014