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Determination of Porosity and its Influence on Specific Surface

Sep 13, 2010

Effects of Hydrated Mg2+ on KCl Flotation

Sep 13, 2010

By R J. Worland, D Bowyer, J L. Mauk

The TerraSpec is a compact field portable mineral analyser that uses non-destructive reflectance spectroscopy for mineral identification. The instrument uses and measures infrared and visible light that is absorbed by certain covalent and molecular bonds (AlOH, FeOH, MgOH, CO32-, OH, H2O and NH4) within the lattice of a mineral at specific wavelengths producing an absorption spectral profile. A variety of minerals can be detected including clays, micas, carbonates, and hydroxides as well as some sulfates and silicates. However, not all minerals are detectable, such as quartz and feldspar. Alteration minerals replacing volcanic rocks have been studied for several epithermal prospects in the lower Waitekauri Valley (Sovereign, Jubilee, Scotia and Jasper Creek) and a geothermal field in the Taupo Volcanic Zone. At the Sovereign, Jubilee, Scotia and Jasper Creek prospects previous XRD investigations determined well developed clay mineral zonation with illite in the west (Sovereign and Jubilee) grading into interstratified illite-smectite (Scotia) and smectite (Jasper Creek) to the east. Although the percent of illite within interstratified illite-smectite could not be determined and some illite-rich illite-smectite (>90 per cent illite) and some smectite-rich illite-smectite (>90 per cent smectite) could be misidentified as illite or smectite respectively, the TerraSpec survey determined the same zonation of illite to illite-smectite and smectite. Common chlorite, rare calcite and local kaolinite were also detected. At the geothermal field, the TerraSpec was primarily used to determine the occurrence of kaolinite, dickite and alunite, which form in acid conditions. Widely spaced (every 50 to 100 m) XRD results are in excellent agreement with closely spaced (every 5 to 10 m) TerraSpec results that further determined the occurrence of these minerals in previously unrecognised intervals. It also determined the occurrence of zoned smectite, illite-smectite, illite, and chlorite alteration. Overall, the TerraSpec is a rapid mineral identification technique that is very useful in delineating the occurrence and distribution of certain minerals in both epithermal deposits and geothermal fields. Although the TerraSpec cannot detect as many minerals as XRD, the TerraSpec allows data collection at a sampling scale and speed (real time) that is not practical by XRD.

Jan 1, 2006

Lime and cement manufacturing has a proud history in Otago, with the earliest lime kilns appearing around 1849 at Caversham and Kaikorai in Dunedin . At Dunback or Makareao (to be precise) three well-type kilns were built by the government in 1899. In 1909 these kilns were leased to the then Milburn Lime and Cement Company. They erected a large brick Schmatolla kiln in 1909, elliptical in plan and fired by coal gas. The kiln operated up until 1944 before being left derelict. The quarry which supplied the kiln also supplied the Burnside Cement works from 1929 up until its closure in 1988. The quarry was shifted to the top of the hill in the 1950s.

Jan 1, 1992

Promoters for Soap Flotation of Phosphate Minerals

Sep 13, 2010

By H Chen

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Mesozoic iron oxide-copper-gold (IOCG) mineralisation in southern Perú and the northern Chile coastal IOCG belt have emerged as two of the major exploration targets in the Central Andes in the last two decades. These Mesozoic Andean IOCG deposits formed in two mineralisation epochs, the Middle-Late Jurassic (170–150 Ma) and Early Cretaceous (130–110 Ma), with the major Cu-rich IOCG deposits located in the Early Cretaceous mineralisation belt. The early studies in some IOCG centres support a magmtic-hydrothermal model for both Cu-rich IOCG deposits and broadly contemporaneous Cu-poor ‘Kiruna-type’ magnetite deposits. However, recent evidence from field, geochronology, fluid inclusions and stable isotopes show that in the major Central Andean deposits (eg Raúl-Condestable, Mina Justa in southern Perú, La Candelaria-Punta del Cobre and Mantoverde in northern Chile), the incursion of evaporite-sourced basinal brines or sea water may be a prerequisite for economic Cu mineralisation. Moreover, the Cu-poor massive magnetite deposits could be interpreted as a product from iron oxide melt, with minimal intervention by non-magmatic fluids. Therefore, they could represent two contrasted deposit types and contain little genetic relationships. The different roles of magmatism during the Mesozoic are responsible for the variable mineralisation in the Central Andes, including IOCG, magnetite and ‘manto-type’ deposits. The ore modelling for both the Middle-Late Jurassic and Early Cretaceous metallogenic epochs in the Central Andes are reconstructed.CITATION:Chen, H, 2015. The Mesozoic iron oxide-copper-gold (IOCG) mineralisation in the Central Andes – a refined IOCG ore-forming model in the Palaeozoic Continental Margin, in Proceedings PACRIM 2015 Congress, pp 251–254 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By W J. Cowie

Several years of operating experience of over 100 gold recovery operations on the West Coast has provided a database from which the basic operating costs of these types of operations can be characterised. Using figures generated from the averaging of plant operating costs throughout the region and financial modelling using Lotus spreadsheets has been developed to analyse both existing and proposed developments. This type of modelling has several uses: 1. Identification of the impact on profitability of changes in management practices, finance costs, operating costs and revenue streams. 2. Project evaluation and planning. 3. Profitability projections for development financing. 4. Troubleshooting with existing operations. 5. Valuation of existing operations and properties.

Jan 1, 1987

By E Topal

Stopes are used in several underground mining methods. Boundary determination of these stopes is generally based on simple rules of thumb. While several stope boundary optimisation techniques are available, they fail to guarantee true optimum results. The first part of this paper reviews some important stope boundary optimisation studies and proposes a new algorithm to optimise stope boundaries and layouts for underground operations. The second part applies the proposed algorithm to a block model to test its ability to produce optimum results and demonstrate its applicability in a number of different scenarios. The results demonstrate that the proposed algorithm can find optimum stope boundaries and layouts in three dimensions for different stope sizes and economic conditions.

Jan 1, 2009

By S Jahanshahi, D R. Swinbourne

The classical metal-slag-gas equilibrium technique was used to study the thermodynamic activity of cobalt, iron and their oxides in iron silicate based slags containing under controlled oxygen potential (3.70 x 10-8 to 2.95 x 10-7 atm) at 1573 K. The measured activity of cobalt oxide in FeOx-25 wt per cent SiO2 slags showed positive deviation from ideal behaviour for melts with up to ten wt per cent CoO. At higher silica contents, the behaviour became closer to ideal and in accord with previous studies on silica saturated slags. The activity coefficient of FeO in these slags had virtually no dependence on the CoO content. Partial substitution of silica by lime resulted in an increase of the activities and activity coefficients of CoO, FeO, Fe2O3 and Fe3O4. The results indicate that saturation of the slag with a magnetite phase occurs at CaO contents of five wt per cent and higher. Phase equilibria studies SiO2-FeO-Fe2O3-CaO slags containing cobalt were also carried out using the drop-quench technique. Results from these experiments confirmed the formation of a magnetite solid solution containing about three wt per cent CoO at lime contents of five wt per cent and higher at 1573 K and 2.9 x 10-7 atm of oxygen.

Jan 1, 2000

By E N. Isaev, L E. Levin

New data on the geology of the Late Jurassic to Holocene sediments cover of the World and associated mineral resources (oil, gas, ferromanganese nodules, ores of massive sulphides and other metals) have been compilled in the Atlas at scale 1:25,000,000 and 1:10,000,000. The work was performed by scientists from four Institutes of Russia (VNIIzarubezhgeologia, VNIIoceangeologia, Vernadsky Institute of Geochemistry and Analytical Chemistry of theRussian Academy of Sciences and Geological Institute of the Russian Academy of Sciences). The Atlas shows variation of thickness and formational composition of the large complexes (Upper Jurassic-Early Cretaceous, Upper Cretaceous Eocene, Oligocene-Neogene, Pliocene-Pleistocene), distribution of oil/gas and ore deposits in each complex, data of deepsea drilling (leg 1-130),  thermo-pressure condition in the sedimentary basins within Circum-Pacific Rim.

Jan 1, 1995

By Y Xie, D Willingham

Predictive maintenance (also known as ‘condition/health monitoring’) refers to the intelligent monitoring of equipment to avoid future failures. In contrast to conventional preventive maintenance, the maintenance schedule is not determined by a prescribed timeline; instead, it is determined by analytic algorithms, such as machine learning, using data collected from equipment sensors and/or via simulation.Predictive maintenance offers the following benefits for operators and equipment manufacturers:- reduces equipment downtime by identifying issues before failure, thereby enabling convenient scheduling of equipment service and extending equipment lifetime- determines the root cause of the failure, enabling appropriate service to be performed without utilising resources to determine a diagnosis- avoids the unnecessary costs of maintenance and unexpected failures- improves safety and product quality.Algorithms and data are critical to predictive maintenance success. Sensor data is first preprocessed using advanced statistical and signal processing techniques; it is then combined with predictive modelling techniques, such as machine learning, to estimate equipment health.Once tested, predictive maintenance algorithms may be used in an operational setting within an IT environment, such as a server or cloud. Alternatively, algorithms may be implemented in an embedded system directly on the equipment, allowing for faster response times and significantly reducing the amount of data sent over the network.CITATION:Willingham, D and Xie, Y, 2017. Predictive maintenance modelling for bearing-based equipment, in Proceedings Iron Ore 2017, pp 627–630 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By D A. Manhire, R M. Flores

The commercial develop of coalbed methane from the Powder River Basin has demonstrated that low-rank coals can be a viable source of gas. Currently over 20 000 coalbed methane wells exist in the Powder River and it is predicted that there will be 50 000 wells by 2010. What makes the Powder River Basin successful is the thickness of the coal (in excess of 30m) as well as the low ash content (

Jan 1, 2002

Management of Mining Wastes in European Union and Developments in Turkey

Sep 13, 2010

It should be stating the æbleeding obviousÆ to say that the most efficient method of recovery must be used during the testing and evaluation phases of an orebody. Furthermore, the company will be literally throwing away money by not using the most efficient recovery plant during mining. This is especially true in the case of a low concentration/high value commodity such as diamonds. Unfortunately, this economic recovery criterion is not always the driving force. Some inexperienced companies think that they can preserve capital by using cheaper, and generally less efficient, recovery plants to mine their product. This philosophy is invariably a fallacy. Furthermore, it is also important to use the correct sized plant for the proposed task. It is no use trying to use a small testing plant to treat large quantities of ore, as this may result in loss of recovery efficiency. The converse is equally true.

Jan 1, 2004

Extraction and Characterisation of Extracellular Polymeric Substances from the Mineral Surface During Bioleaching of Chalcopyrite Concentrate A mixed culture of moderately thermophilic microorganisms was used to bioleach chalcopyrite concentrate in a stirred tank reactor. The results show that up to 84.7 per cent of copper extraction could be achieved in 24 days at a pulp density of 6 per cent. The leaching rate of chalcopyrite concentrate tended to increase with an increase of dissolved total iron concentration. Furthermore, the extracellular polymeric substance (EPS) on the surface of the chalcopyrite concentrate was extracted and analysed. EPS was extracted at the first, third, eighth, 16th and 24th day during bioleaching, which mainly consisted of proteins, lipids, sugars and ferric irons. After the eighth day the total amount of EPS remained relatively constant. However, the amount of ferric iron in the EPS decreased in a large scale. The ore residue analysis indicates that the decrease of ferric iron was mainly due to the formation of jarosite on the mineral surface.

Sep 13, 2010

Truck fires in a tunnel can create heat release rates (HRR) significantly higher than 100 MW. Because of a fast spread of smoke and heat the self-rescuing period is shortened significantly. Furthermore, it was experienced that firefighters are not able to approach the fire because of enormous heat and radiation. As consequence, the fire may spread to adjacent vehicles, which is reported for distances of more than 50 m. Tunnels can be damaged severely by fires and the repair works causes long closing time of tunnels. In addition to direct costs for the refurbishment of the tunnel, further economic losses will occur due to the closure time. Conventional deluge systems in Japanese and Australian road tunnels have been known since the 1960s. During the last years the research work was concentrated in the development of more effective and cost-effective solutions based on water mist technology. Orientating fire tests as well as specifications of minimum requirements were carried out within the European research project UPTUN. This basic work was extended by the safety of life in tunnels (SOLIT) research project, funded by the German government. The scope of SOLIT was not only to study the effects of water mist fire suppression systems in tunnels, but also the interactions with other safety systems, such as fire detection, passive fire protection or ventilation. Furthermore, the integration of active fire suppression systems into a holistic tunnel safety system was part of the work program. Within this research project a large-scale fire test program with more than 50 fire tests, including 25 truck fires with a potential HRR of almost 200 MW, was carried out in the test tunnel of San Pedro des Anes (Spain). Furthermore, a two-week testing and training period with the Madrid Fire Brigade was carried out after the SOLIT program. Two fundamental results were achieved during the fire tests:Primarily, water mist systems are able to control the HRR of fires in tunnels, so the atmosphere will be improved significantly. Hazardous effects of toxic smoke on people will be reduced and due to the reduction of temperatures and radiation, a firefighterÆs approach is improved significantly. Furthermore, the fire spread will be hampered and the thermal load on the building structure also be reduced. Secondarily, due to positive interactions with the ventilation system, the effectiveness of a tunnel ventilation system, longitudinal as well as semi-transversal, is increased significantly. Based on the results of the SOLIT research project, a water mist system was applied into several parts of the M30 tunnels in Madrid. As a basic principle the technical equipment and the methodology of implementation comply with the UPTUN 251 guidance, recommending minimum standards for water-based fire suppression systems in tunnels.

Jan 1, 2008

By C Skublak

The Government of Canada recently passed a new regulation to control the liquid discharges from metal mines in Canada. The Metal Mining Effluent Regulation of the Federal Fisheries Act will come into force within the next six months. As a result the Ontario Regional Office of Environment Canada has developed a compliance promotion program to accompany the new regulation. How the mines implement the regulation will be key to its success. This paper will briefly outline the components of this regulation, including the reporting structure, the discharge parameters and limits, as well as the requirement for the mines to conduct long-term environmental effects monitoring on their effluent discharge. The presentation will give a brief account of the compliance promotion program, and then focus on the spill trends from Ontario mining operations. The province of Ontario has the largest concentration of metal mining operations in the country with approximately 40 active mines.

Jan 1, 2002

Adsorption Isotherm Measurement of Sodium Oleate on Haematite Using Differential Thermal Analysis

Sep 13, 2010

Newmont Waihi Operations is participating in the initiation of a community liaison forum in association with the local district council. The objective is to provide a forum for the free and regular exchange of ideas, concerns and information, and through improved communication seek to achieve a more comprehensive set of solutions to community, operating and closure issues associated with Martha Mine. A similar liaison forum has been operated on two previous occasions during earlier phases of the present mine's operation. This paper deals with the practical aspects of setting up a liaison forum to act as an effective conduit between regulators, mine operators, local businesses and the community. The mechanisms and procedures for identifying community issues and concerns are dealt with. The actions and structures required to ensure effective ongoing community 'buy in' at all levels are discussed. Corporate philosophies are addressed. Specific examples from Martha Mine, Waihi New Zealand will be used to illustrate the paper. This will include a brief explanation of previous and current community issues, Newmont Waihi's operations both at Martha Mine and the proposed Favona underground mine, and the practical issues involved in setting up a liaison forum.

Jan 1, 2003

Study on Reasonable Mineral Processing Flow Sheet of Yunfu Low-Grade Pyrite Ores Low-grade ores in Yunfu Pyrite Mining Area were investigated, in order to find an economical, reasonable and environment-friendly mineral processing technology, which is of low consumption and high efficiency in pyrite recovering, which can ensure that the quality of pyrite concentrate product is eligible for sale and the sulfur content of the discharged tailings meets the national emission standards. A flow sheet with a classification, a jigging for coarse-grain minerals and a spiral chute separation for fine-grained minerals was adopted, and the sulfur grade and recovery of the pyrite concentrate is 35.50 per cent and 86.70 per cent respectively, while the grade of tailings is only 6.70 per cent.

Sep 13, 2010