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Paiam is a new township in the high mountains of Papua New Guinea built in association with the Porgera Joint Venture mine, one of the world's largest and most remote open cut gold mines. The Paiam town project is an interesting and genuine attempt at building sustainability into a community associated with a mine. A result of a tri-party agreement between a resource developer, government and land owners, this town is a good example of appropriate utilisation of benefits, obtained from resource development, directed at achieving a sustainable environment at local and regional levels.   Mining brought technology and income to the region, although as most mine staff fly directly in and out, local landowners considered there was a limited flow of benefits within the nearby townships. An agreement with government and mine was reached that more mine personnel and their families be housed locally. In 1998, we, a firm of Landscape Architects and Heritage Consultants based in Cairns, Queensland, were engaged to assist develop the fledgling town of Paiam into a livable and sustainable town and to produce material that would convey that information to stakeholders.   The design focused on establishing a sustainable town, with livability, urban form, aesthetics and opportunities for economic, social and cultural development. Aiming to be a livable town for locals and mine staff it included a market place designed as a focus for town life, essential for social cohesion and economic opportunities.   Located at 2200 m on steep rainforest clad topography, the town development has been laid out using an appropriate urban form based on organic village layouts. Clusters of houses allow for a common public area so children's play is monitored assisting with a sense of community similar to a traditional defensible village. Aesthetical consideration helps in developing community pride whilst maximising potential for development of a tourist industry.   Opportunities for ongoing economic development were incorporated in the design and construction process. These included developing skills and trades to service the region and to provide skills, development, income opportunities and infrastructure to last beyond mine closure. Administration procedures were set in place to form the basis of good governance.   The shift from traditional subsistence lifestyle to a sustainable community with traditional attributes was the project's goal and is being achieved.

Jun 1, 2010

By V M. Silva, P A. A Martins, V O. Matthew, A L. S Fonseca, E B. Cunha, A J. D Ferrari, E M. S Silva, A C. Silva, D R. T Vilela

The Anglo American phosphate mine is located in the Brazilian state of Goiás and possesses one of Brazil’s most important phosphate rock deposits, with the site being the country’s second largest producer of phosphate rock concentrate. Despite the site having been in operation since 1979, the mining team only started using explosives in 2004 when rocks with greater hardness started to appear in the mine’s geological profile. Rock excavation was previously performed mechanically. Until 2013, only rocks with high hardness were blasted, this following the standard drilling grid that was defined in 2004 without any changes in the blast parameters. The aim of this paper is to show how fragmentation optimisation has yielded positive results at all stages of the production chain, from the mine to the mill passing through an impact hammer crusher, a rod mill and ball mill, operating in close circuit with hydrocyclones.While incorporating the mine to mill holistic approach during the operational integration, the focus was on defining the blasting domains and respective optimal fragmentation and measuring the benefits of blasting in terms of reduction in energy and grinding media consumed in the comminution processes. In the first stage, the blasting team made changes to the blasting parameters and assessed the effects of these changes on fragmentation using computer software and on-site measurements. This generated a database that made it possible to divide the mine into blasting domains. For the second stage, teams from the plant, geology, mine planning and operation departments jointly made comparisons between the performance when processing stockpiles, which only included high hardness blasted ore (20–30 per cent of blasted ore). Changing the drilling grid’s size from 3.0 m × 3.8 m to 2.0 m × 2.6 m for high hardness rock with the presence of silicates resulted in a 40 per cent reduction in the P80 for the blasted material (from 459 to 278 mm), while changing the grid from 3.0 m × 3.8 m to 2.6 m × 3.2 m for high hardness rock without the presence of silicates generated a reduction of 25 per cent (from 270 to 204 mm). There were gains observed from the measurements at the mineral processing plant in terms of specific energy spent on comminution and on the consumption of grinding bodies in the rod mill. There was a measured reduction of circulating load during secondary grinding and a reduction in slime generation.CITATION:Silva, A C, Martins, P A A, Silva, E M S, Fonseca, A L S, Ferrari, A J D, Cunha, E B, Silva, V M, Matthew, V O and Vilela, D R T, 2015. Fragmentation optimisation – adopting mine to mill for reducing costs and increasing productivity, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 363–368 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By J P. van Dyk

A new crude ilmenite beneficiation process was recently proposed that allowed for the preparation of a smelter grade ilmenite from ilmenite with elevated chromium content. Magnetising roasting was not utilised in the process. As part of this circuit an ilmenite low susceptible reject stream was produced that had a low magnetic susceptibility. In this article a magnetising roasting process was investigated to beneficiate this material. Tests were conducted on material produced by pilot scale simulations on a typical South African East Coast heavy mineral reserve. The results obtained were compared to those published in literature for crude ilmenite. The small-scale experiments were used to define approximate operational limits for the oxidising roasting of a low susceptible ilmenite low susceptible reject stream, although industrial roasting conditions may differ significantly from those obtained in laboratory units. In a next phase these results will be confirmed on pilot plant scale.

Jan 1, 2001

By S France

The Waterview Connection will complete a strategic Auckland motorway route linking the south, west and north. The project will comprise 2.5 km of ‘undrained’ driven tunnels and 900 m of drained cut-and-cover tunnel and portals.The project is aligned beneath a stream valley of Oakley Creek incised through alluvium and in places overlain by landfill, between Mt Albert volcano and a ridge formed in alternating sandstones and siltstones. The hydrogeology of the area is complex with perched aquifers in compressible soils, cascading water levels in fractured rock aquifers, and discontinuous higher permeability units resulting in artesian water levels and groundwater springs.Numerical groundwater modelling was undertaken to assess the potential effects of tunnel construction and long-term operation on the groundwater system; the magnitude and extent of changes in groundwater level and the resulting potential for settlement, buoyancy effects, contaminant migration and adverse effects on creek base flow. Modelling also provides inputs to tunnel design such as groundwater seepage volumes and water pressures.The driven tunnel will be ‘undrained’ long-term so potential effects on the groundwater system are limited to short-term dewatering during construction. Significant project time and cost savings can be made if the portal areas are permanently ‘drained’, but this means potential effects are greatest in the long term condition.This paper summarises the investigations, implications of the complex hydrogeological setting on tunnel design and environmental assessments, and groundwater modelling undertaken during the planning stage of this project. The groundwater modelling has been used to incorporate mitigation options in tunnel design and construction sequencing; a comprehensive monitoring program will be used to trigger appropriate responses should effects differ from those predicted.

Mar 8, 2011

By M I. Pownceby, W J. Bruckard

A South African chromite sample was subjected to characterisation and physical beneficiation testwork in order to assess its suitability to produce an upgraded chromite product with a silica level of <1 per cent SiO2 and a chromite level of >46 per cent Cr2O3. Chemical analysis by XRF indicated that the bulk material had a Cr2O3 content of 40.5 per cent w/w and a SiO2 content of 7.5 per cent w/w. Combined XRF analysis with sizing data showed that the majority (~70 per cent) of the siliceous material was present in the +600 ¦m fraction while ~70 per cent of the Cr2O3 was in the -600 ¦m fraction. Qualitative mineral phase analysis by XRD indicated that the sample mineralogy was dominated by ferrian-magnesiochromite spinel ([Fe,Mg]Cr2O4) and aluminium-chromite spinel (Fe[Al,Cr]2O4), with enstatite (Mg2Si2O6), haematite (Fe2O3) and anorthite (CaAl2Si2O8) as minor phases. SEM and EMP characterisation showed that the silica was mainly present in discrete enstatite grains but lesser amounts were also present as the high silica phases plagioclase and enstatite on the edge of grains. Wet gravity separation performed on sized fractions (-600+106 ¦m size range) from the -2.0 mm (primary) ore as well as the ore that had been crushed to pass 0.6 mm (secondary) showed that stage crushing of the -2 mm +600 ¦m fraction followed by wet gravity separation upgraded the Cr2O3 grade at 70 per cent Cr2O3 recovery from ~44 per cent Cr2O3 in the primary material to 46 per cent Cr2O3 (the target grade specification) in the secondary sample. It also showed that the stage crushing of this +600 ¦m fraction at a cut-off level of one per cent SiO2 increased the cumulative Cr2O3 recovery from ~50 per cent in the primary material to ~63 per cent in the secondary sample in the same size range of -600+106 ¦m. The extent to which additional crushing could lead to improved chromite recoveries at the required chromite and silica grade target specifications was not determined. This experience demonstrates that prior to processing test work being conducted, a thorough understanding of the chemistry and mineralogy of the test sample promotes efficient and targeted processing research.

Jan 1, 2008

By A McCallum, J Abols, G Patrick, G Johansen

The authors challenge the traditional thinking that whole ore cyanidation followed by Carbon in Pulp (CIP) or Carbon in Leach (CIL) should be applied as a standard process in the majority of gold processing flow sheets. The concept of whole ore leaching by using cyanide can result in unnecessary environmental and capital risk. Alternative, currently available technologies can be used to provide the desired level of gold recovery at a much lower installed cost and less impact on the environment. Gravity concentration, alone or in conjunction with flotation, can produce a gold bearing concentrate that can then be fed directly to a batch or continuous intensive cyanidation unit. The In-line Leach Reactor (ILR) is an intensive cyanidation unit developed by Gekko Systems of Australia. Advantages of this technology include significantly reduced capital outlays for greenfield plants or plant upgrades and increased investor returns. Reduction of onsite cyanide and carbon inventories improves plant safety, materials handling and site security. By using direct electrowinning to treat the gold bearing solutions produced by the ILR, the need for a conventional carbon stripping circuit is removed. Potential also exists to increase grind size û saving energy, further reducing capital and operating costs and decreasing the environmental impact of a mill. Detoxification of cyanide before the release of solution to the tailings dam can minimise tailings disposal and containment requirements. When used in the right application the proposed process will have little or no impact on gold recovery and may actually increase recovery for complex ores. Areas applicable to this type of treatment include: plants in environmentally sensitive regions, lower tonnage higher grade deposits, coarse gold deposits, and preg robbing ores û some of which may not currently be economically feasible using standard processes and flow sheets. We have provided two examples of such projects, where an alternative to whole ore leach and CIP or CIL has the potential to deliver these benefits.

Jan 1, 2004

The paper provides an overview of the development and content of APCOM symposia since their inception in 1961. This development is set within the context of the academic environment in which much of the research published at APCOM symposia is conducted. This environment includes rigorous external assessment of research quality at national levels and against international benchmarks, which carries significant consequences for funding and for the continued existence of the academic minerals industry disciplines. Adverse consequences that undermine the academic provision of mining and resource engineering will impact negatively on the minerals industry by reducing the level of research and education resources available to it.The traditional reductionist approach to research is contrasted with the inter-disciplinary approach that is required to address the complex systems problems that the minerals industry will have to address to ensure its technical, economical and environmental sustainability. Such an approach offers a means of raising research profiles, of establishing mutually beneficial academic-industry engagement and provides an opportunity for APCOM to take a lead role in identifying the research and development agenda for the future

Sep 26, 2011

By G W. Swana

Elastoplastic parameter is a parameter that describe how much materials behave elastically up to certain stress states and plastically thereafter (Hudson and Harrison, 1997). In the continuum analysis, two main parameters of the elastoplastic parameter are modulus elasticity and Poisson’s ratio. In the slope, elastoplastic parameter holds the main role for stability related to deformation in ductile type of rock. There’s a limitation to determine elastic or plastic deformation at the field for ductile rock type. Field manifestation commonly showed that there was no accumulation zone during and after the sliding failure mechanism, in other hand, at the research area, manifestation of deformation at the toe of slope only indicated by bulging shape. This paper will focus at the sliding failure occurred at Coal mining Pit Y owned by Arutmin Indonesia, which according to failure investigation report similar with the condition described above. This paper also will be based on two hypotheses, first hypothesis is claystone rock mass has not been reached plastic deformation yet and the second hypothesis is there is a chance that elastoplastic parameter of the rock mass has been changed during the deformation/sliding failure process. Research method of this paper are back analysis using probabilistic analysis in Finite Element Method (FEM), which conducted before and after failure. Then, the result of the displacement or deformation of the analysis will be checked with the actual deformation shape. Meanwhile, the change of the elastoplastic parameter will be analysed and interpreted. This paper hopefully able to be developed to study about elastoplastic behaviour of rock mass in actual condition and the influence of another uncertainty factor which determine the slope stability.

Nov 29, 2022

By J Thoma, W Skinner, W Stewart, R Smart

The acid neutralisation capacity (ANC) of rock sample containing significant iron carbonates and/or reactive framboidal pyrite can be a difficult parameter to determine. Results indicated that negative ANC results can occur if reactive sulfide minerals are present; and an over-estimation of ANC will result if significant Fe rich carbonate minerals are present during industry standard ANC tests. In this paper we investigate these problems. Results showed that a significant lag period may be needed (up to 432 hours) after standard Sobek ANC type tests of siderite for the complete hydrolysis of iron released from this mineral. This even occurred with standard industry modifications that included the addition of two drops of hydrogen peroxide. In this work we use a modified Sobek test that included filtering, and thence continued hydrogen peroxide addition until there was no subsequent pH drop, followed by back titration to pH 7.0. Results indicated that the ANC for the siderite (after zero hours) was immediately comparable to the ANC determined after 432 hours lag by standard Sobek type tests; and a calculated theoretical carbonate ANC. Investigations of coal waste samples containing significant framboidal pyrite indicated that standard Sobek ANC type tests can result in negative ANC values due to the oxidation of this reactive pyrite. Because sulfide acidity is already addressed by the MPA calculation, the inclusion of sulfide acidity as part of the ANC determination is effectively biased towards acid generation and thus positive NAPP values. Negative ANC values cannot be ignored or assumed to be zero as this masks any actual ANC available within the sample, which may possibly affect AMD categorisation. This sulfide acidity can be factored out using the quantity of S in the ANC digestion liquor and knowing the non-acid generating sulfate content of the sample prior to ANC testing. Results indicated that incomplete iron hydrolysis at the completion of the Modified Sobek ANC test is not only a function of iron carbonate dissolution, but is also related to the dissolution of Fe-sulfate salts, and the oxidation of reactive sulfides such as framboidal pyrite.

Jan 1, 2003

By P Kumar, J Safarian

Understanding how ore interacts with flux particles at elevated temperatures to create molten slag is crucial since it governs the dynamics of a chemical reaction. This study explores the smelting behaviour of pre-reduced Nchwaning manganese ore when combined with lime, with the objective of examining the evolving interaction between pre-reduced ore particles and lime over time. The research sheds light on the interaction between solid and liquid and the phases that emerge during this process. To achieve this, a sessile drop furnace was employed to rapidly heat the materials positioned adjacent to each other on an alumina substrate and to observe the smelting process as it unfolded over time. This method allowed for the direct observation of the melting temperatures and the flux-ore reaction progression rate, and the potential disruptive events that might occur. By comparing the molten interfaces of the fluxed materials at various time intervals, this study provides insights into the relative rate of slag formation from the two materials. The results indicate that the main slag formation initiated at approximately 1400°C and continued to advance with time, with complete mixing occurring around 1500°C. The possible phases formed were identified using Scanning Electron Microscopy and modelled using Fact Sage thermodynamic software. In addition, the iron particles in the pre-reduced Mn ore were separated and settled from a rich MnO-containing slag. It was found that the separation of molten iron droplets from the slag depends on the rate of solid MnO particles dissolution into the adjacent slag phase.

Jun 19, 2024

By Dean J. A, Taube A, White A. H, Messenger P. R, Jones I. W O, Huston D. L

The 50 million tonne Mount Morgan gold-copper deposit (4.99 g/t Au, 0.72 per cent Cu) was an irregular pipe-like body of quartz and pyrite, with subordinate chalcopyrite, magnetite and gold. Mineralisation was hosted by the Middle Devonian Mine Corridor Volcanics which occur as a roof pendant within the Late Devonian Mount Morgan Tonalite. On three sides, the deposit was enclosed by a series of normal, concave, listric faults and surrounded by outward-dipping Mine Corridor Volcanics. The tonalite which bounded the western side of the deposit transgresses the domal structure with no apparent interference. A pipe of intense, texturally-destructive, quartz-sericite-chlorite ¦ pyrite underlay and partly surrounded the deposit.The volcanic setting of the deposit, its shape, metal content and associated footwall alteration are consistent with a subsea-floor replacement origin for the gold-copper mineralisation. Mineralogical studies have confirmed the deposit has been recrystallised and annealed by a thermal metamorphic event, most likely the intrusion of the Mount Morgan Tonalite. Pyrrhotite Pipe mineralisation replaces annealed massive pyrite, suggesting that it formed during retrogressive metasomatism associated with tonalite emplacement. Telluride minerals have a close association with chalcopyrite, and no evidence for a late telluride paragenetic stage was observed. Telluride mineralisation is inferred to be genetically related to the massive sulphide mineralisation, and a separate magmatogenic origin for this mineralisation is discounted.

Jan 1, 1993

The disadvantages of the present zinc producing methods, RLE and ISP, are high energy consumption and environmental problems. Therefore, efforts have been directed in Outokumpu Zinc towards the development of alternate routes. One interesting pyrometallurgical process to produce zinc is to inject zinc calcine together with a solid reductant into molten iron, saturated with carbon. This process has been studied by thermodynamic calculations, laboratory tests and mini-pilot test runs at Outokumpu Research Oy, Pori, Finland. The results of these tests are presented and discussed in this paper. The mini-pilot tests demonstrated that over 97 per cent evaporation of the zinc was possible using a reactive coal dust as the reducing agent. The recovery of zinc in the metal phase was at best 88 per cent of input zinc, but only part reported in molten lead in the splash condenser. The final metallic zinc contained at best 98 per cent Zn, the main impurities being dissolved lead and coal carried along with the flue dusts.

Jan 1, 1993

By G J. Massoth, K Faure, A G, R G. Ditchburn, I J. Graham

From modest beginnings in 1996, research into the mineral potential of New ZealandÆs Exclusive Economic Zone has progressed into a major multidisciplinary component of GNSÆs recently funded 6-year æMineral Wealth of NZ and its EEZÆ Programme. In excess of $7.5 M of research funding has been expended, plus $10 M leveraged via collaborations with NIWA (NZ), NOAA (USA), JAMSTEC (Japan), U. Kiel (Germany) and ANU (Australia), whose scientists have contributed hugely to research cruises, as well as subsequent analysis and publication. The 1999 NZAPLUME I cruise was the first research expedition to systematically locate, and chemically characterise, submarine hydrothermal venting associated with arc volcanoes of the southern part the Kermadec intra oceanic arc system. This was followed by the 2002 NZAPLUME II and 2004 NZAPLUME III cruises to the mid- and northern-sections of the Kermadec arc, respectively. Combined, these cruises have surveyed 1300 km of the volcanic chain (from Whakatane to Monowai), including 34 major volcanic centres. Together with concurrent surveys in the Tonga arc, this is now the longest continuous stretch of intra oceanic arc to be surveyed for hydrothermal emissions. Most of the volcanic centres are characterised by simple cones although 30 per cent contain caldera complexes, and compositions range from basalt through to rhyolite. Massive sulphide mineralisation has been recovered from several volcanic centres in the southern Kermadecs (Clark, Rumble II West and Brothers), suggesting the existence of significant Au and base metal bearing deposits along the arc front.

Jan 1, 2005

A genesis based on new developments in the physical chemistry and flow properties of colloidal substances is proposed for the pipe-like Peko orebody. The rheological behaviour of sediments is governed by the contained colloids. Remobilization of thick pasty sediment during diagenesis is regarded as an essential step in the concentration of metal dispersed in sediments. At a high concentration the sediment pore fluid is a dense gelloid such that van der Waals attractive forces between the colloidal particles exceeds the coulombic repulsion. This permits accretion of the colloids into globular clots and their fracture fragments. These have a uniform size distribution dependent upon the rate of shear, and the sediment lithifies to clotted, porphyry-like, "gritty", dolomitic or igneous-looking intrusions and flows. The physical chemical properties of natural sediment colloids appear adequate to account for ore formation.Adsorption accounts for the dispersion and retention of metal in sediments. Accretion accounts for the segregation of the colloidal materials to give the various types of clotted igneous-looking intrusive source rocks. Syneresis enables the colloids to spontaneously draw together and to dehydrate. Formation of an ordered lattice achieves a lower energy state and desorbs metals and insoluble metal compounds "particle by particle" into the escaping water of hydration and pore water. Peptization enables migration of the metal hydrosols as stable dispersions until they merge for outflow through seepage zones or water extrusion channels. Nucleation and concretion precipitate the metal dispersoids from pore waters seeping through hydrous parts of the source rock, porous beds, faults, and zones of weakness by which the connate waters leave the lithifying sediments. Gelatinous precipitated mineral matter in the ore channels is capable of thixotropic reliquefaction when disturbed by shock or movement. Local reintrusion, flowage, interveinings,brecciation, and intermixing of the materials is the result.The principles of the suggested genesis are applicable to both syngenetic and epigenetic mineral accumulations.

Jan 1, 1966

The Kingsgate molybdenite pipes are considered on petrochemical data and field occurrence to be, possibly, epi-magmatic plutonic offshoots grading into hydrothermal bodies. There is reason to believe that the ore is derived from a highly acid granite of type similar to that of the tin bearing areas of northern New England. The mineralogy, microtextures and paragenesis of the ore are discussed.INTRODUCTIONThe Kingsgate Mining Field is situated in steep, heavily timbered terrain 18 miles E.N.E. of Glen Innes and 430 miles north of Sydney. Bismuth and molybdenum ores were discovered at Kingsgate (Yarrow Creek) in 1877. Subsequently some 50 pipes were developed yielding tonnages which at the peak of operations, 1905 to 1920, rivalled production from the rich deposits of northern Queensland.Attempts to revive the field have been made periodically and small parcels of ore have been forthcoming.' During World War II demand for piezioelectric quartz again focussed attention on Kingsgate but twinning and other imperfections of the quartz prevented all but a minor exploitation of the otherwise noteworthy crystals of this locality.There is reason to believe that the ore at Kingsgate is not exhausted through exploration and mining costs would probably be high due to the capricious nature of the pipes and to the irregular distribution of rich ore shoots within them.

Jan 1, 1962

By Tripathy A. K, Satapathy B. K, Nayak B, Mohanty J. N, Dey D. N

The paper deals with the metallographic tudy of heat treated chromite and chromite-coke composite briquettes. The briquettes, prepared from chromite concentrate of Orissa Mines using molasses-lime, dextrinelime and tamarind seed as binders, were subjected to different temperatures and examined metallographically. The change of phase with temperature was analysed by X-ray diffraction.

Jan 1, 1987

Additional Attractive Force Between Alumina Particles Due to Low Solubility of Dicarboxylic Acids

Sep 13, 2010

Longwall mining has historically been considered an application for only deep reserves. This has changed in the recent past as longwall has become competitive with surface mining. Many resources marked for stripping now he in the domain of longwall. Today, the best longwall mines compete with strip mines operating in even the lowest stripping ratios. Longwall mining has become more widely applicable than it ever has been in the past and it is now generally considered the method of choice in situations where high levels of coal production are required. But the best way to use longwall mining has become less certain with the opportunities that highwall access provides. Wall-to-wall mining is the use of retreating longwall developed from and retreating toward a highwall. As a surface mine reaches its ultimate highwall, the opportunity for longwall punch mining or wall-to-wall mining is obvious. There are several clear operating advantages to operating a longwall in this way and where highwalls are available, the best economic decision will generally favor planning a direct approach. Yet wall-to-wall is not applicable in every situation even when highwalls are available. Moreover, the advantages of wall-to-wall mining do not always justify the cost of trenching or box cuts to access coal . However, many tactical advantages of operating from the highwall can be realized with the use of specially equipped blind drilled or raised bored shafts. This paper discusses novel techniques for a shaft assisted mining system which permits the addition of conveyor structure and mine systems from the surface to the face for advance and retreat mining with longwall, shortwall or room and pillar panels.

Jan 1, 1998

Validation and Application of Filtration Theory to Plate and Frame Pressure Filtration - From Laboratory to Full Scale

Sep 13, 2010

Research on Universal Depressant of Talc and Serpentine

Sep 13, 2010