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Recycling of Process Water in Sulfides Processing and Flotation Selectivity

Sep 13, 2010

Study on Desulfurisation and Deashing for Medium-High Sulfur Coal Using Shaking Table As important coal resources, medium- high sulfur accounts for a significant part of the coal reserve in China. The environmental regulations and fuel standard requires sulfur and ash to be removed before it is used, so as to save energy and decrease the emission. Therefore, the effective desulfurisation and deashing technologies are urgent needed. However, due to the local characteristics of the coal, specific technology with optimum operation parameters is required to develop for different local coal. Qinglong is a district of Guizhou Province, which has large medium to high sulfur contained coal reserve. In this paper, medium-high sulfur coal is sampled from Qinglong, Guizhou province. Some basic characteristics such as the mineralogical composition of the coal rock, the monomer existing state and the granulometric composition are determined by X-ray diffraction quantitative analysis and polarisation microscope analysis respectively. Adopting the classified feed method, shaking table tests show that the feed pulp concentration is 20 per cent, the stroke is 13mm, the frequency of the stroke is 380 per min, the cross slope is 3¦ and the volume of wash water is 5.2 L per min. Under such condition, aggregate processed coal yield is 72.87 per cent and sulfur content decrease to 1.31 per cent With shaking table technology of 'First stage rough and intermediate further fine benefication', the yield of concentrate coal increased from 72.87 per cent to 81.21 per cent, while the sulfur content reduced to 1.35 per cent.

Sep 13, 2010

Combined Flow Sheet for Treatment and Recycling of Municipal Solid Waste (MSW) with Complex Morphological Composition

Sep 13, 2010

By K L. Brown

In the Waiotapu geothermal area only Champagne Pool, 109 ng/L, and Waiotapu Geyser, 7.6 ng/L, have dissolved Au concentrations greater than 5 ng/L and most springs have concentrations less than 2 ng/L. When Au concentration data are combined with other physico-chemical data from each spring including; pH, reduced sulphur concentration and temperature, the degree of Au saturation can be calculated. All samples sites except Champagne Pool, Waiotapu Geyser and the Artists Palette are under-saturated with respect to Au(s) by 1 to 3 orders of magnitude. This indicates that adsorption or co-precipitation or both are important processes depositing Au beneath hot springs. Deposition of Au by adsorption or co-precipitation beneath hot springs implies that dissolved Au may not have to reach saturation concentrations for ore to deposit. This interpretation is supported by the presence of substantial Au as sub-microscopic components within sulphide minerals in ore deposits and indicates depositional efficiency beyond that possible through precipitation of Au(s).

Jan 1, 2004

By M Quinteiro, Å Sundqvist

What is special about being a female mine manager? We do not believe that the challenge is greater for women in managing a mine compared to managerial positions in other male-dominated businesses. The challenge lies in the fact that it is a male-dominated business. Being a leader belonging to a minority creates a situation where competence not only lies in having technical knowledge or general leadership characteristics, but also in acquiring an understanding of the male norm and being able to behave and communicate effectively in the organisation.In order to move towards a better gender balance at senior levels it is important to set measurable objectives on desirable proportions between women and men at management levels within the company. Focus and action are required to achieve this goal. At LKAB, the current target is to reach 25 per cent women in the total workforce by 2020. To date, LKAB has reached 19.4 per cent women in the total workforce, and the number of women in management positions is 19.9 per cent.It is of vital importance to create a non-discriminating working environment to achieve equal opportunities at the workplace, to be able to use the whole workforce as a resource for recruitment of professionals and managers, thereby improving decision-making, productivity, efficiency and profitability.Women as mine managers is not a utopia, but rather an effect of long-term investments in actions that result in equal opportunities for all employees.CITATION:Quinteiro, M and Sundqvist, Å, 2016. Women as mine managers – a utopia?, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016) , pp 43–48 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By P Maillet, A J. Crawford, S M. Eggins

TheFiji Islands are remnants of a once continuous Solomon-Vanuatu-Fiji-Tonga volcanic arc (the Vitiaz arc), located at the boundary between the Indian-Australian and Pacific plates. They record a history of: (i)                  arc volcanism the late Eocene to late Miocene, (ii)                an extensive magmatic response to arc rifting (5.5 - 3.0 Ma) during which volcanism was dominated by shoshonitic to tholeiitic basalts, and as rifting continued, (iii)               a transition from arc to intraplate volcanism.   The Hunter Ridge-Hunter Fracture Zone separates the inactive South Fiji Basin from the actively spreading North Fiji Basin, and has been considered to be a transform zone, almost parallel to the motion vector of the Australian plate. However rocks dredged during the 1993 æAlizeÆ cruise, from along the northern part of the Hunter Ridge are typical arc tholeiites, and therefore demand that subduction has occurred beneath the Hunter Ridge sometime during the last ~5 Ma. The Kadavu Island group, south westernmost Fiji, lies at the north-eastern end of the Hunter Ridge-Hunter Fracture Zone, and possibly results from oblique subduction of South Fiji Basin oceanic crust, which may have accompanied the anticlockwise rotation of Fiji during opening of the North Fiji Basin. These islands consist dominantly of 3.4 - 0.5 Ma old medium-high K andesites and dacites, with many traits typical of subduction-related volcanics, ie predominance of intermediate members (55 - 65% SiO2) no Fe enrichment, TiO2<1%, and negative Nb-Ta anomalies. These features contrast strongly with volcanics from elsewhere in Fiji around this time, where volcanic centres produced Om-like intraplate olivine basalts. The Kadavu Islands become gradually younger to the southwest, and show a significant decrease in K2O with time. The north easternmost islands (Astrolabe islands) containing the oldest rocks (~3 Ma) have shoshonitic affinities and are considered to be of similar age and composition to the youngest shoshonites found elsewhere in Fiji.

Jan 1, 1995

Particle Mechanics and the Design of Cyclone Tribochargers Triboelectric separation is a dry electrostatic technique that has shown promise in several particle processing applications. A tribocharger uses contact or friction to differentially charge particles of different materials, which are then separated by an electric field. The initial tribocharging process is poorly understood, with tribocharger design and operation largely a matter of trial and error. A better physical understanding of tribocharger operation would therefore be of immense value in the optimisation of triboelectric separation processes. A combination of charge measurements, trajectory modelling and high-speed video has been used to relate charging to particle mechanics in a cylindrical pneumatic cyclone, one of the most effective tribochargers for mineral separation applications, and the preliminary results are presented here. The consequences of these observations for cyclone tribocharger design and operation, and for tribocharger design in general, are discussed.  

Sep 13, 2010

The increased cost of imported oil fuels, coupled with our understandable reluctance to commit ourselves to the use of nuclear energy, has resulted in a renewed reliance on coal as a primary source of energy. New Zealand is fortunate in being fairly well endowed in its coal resources, but their exploitation until now, has been on a relatively small scale. Future exploitation, whether from underground or open cast mines, must be on a very much larger scale. This paper outlines some of the factors which should be considered in planning large open cast mines.

Jan 1, 1976

By R Stefansen

Stockyard operations are governed by the interaction between the different disciplines required to successfully schedule and control the supply chain of raw material through the stockyard in combination with the effectivity of the operation of the stockyard equipment. The system demonstrates a proven technology for implementing a centralised operation of full unmanned stockyard equipment, using a high precision absolute positioning system based on a Real-Time Kinematic (RTK) Global Navigation Satellite System (GNSS) receivers in combination with 3D rangefinders. The system implementation maps the surface profile of the stockyard inventory and allows in combination with proprietary algorithms for full operation of the stockyard machines without on-board operators. The operational impact of delayering the process by moving to a centralised operation is examined, together with the combined effect on the overall safety in the stockyard as a result of a change in reliance on operator skill dependencies. Average performance gains range from 10–20 per cent. The performance of the automation system is related to a consistency and reliability of uniform operation, which has an impact on the life expectancy and the effectiveness of the equipment. The effects of having instantaneous and correct information about the stockyard inventory volume measurement are investigated in relation towards spot price trading in current fast reacting markets.CITATION:Stefansen, R, 2017. Advanced automation for centralised stockyard operations, in Proceedings Iron Ore 2017, pp 105–110 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By R L. Brathwaite, S E. Belliss

Linear and semi-circular features were mapped in the volcanic terrain of the southernCoromandel Peninsula, North Island, using JERS-1 synthetic aperture radar (SAR), Landsat-4 Thematic Mapper, and SPOT-2 multispectral satellite data, digital elevation models, and aeromagnetic data. The mapped features typically correspond to recognised physiographic features and are thus a useful aid to mapping the structural trends in the region. Major linear features exhibit a strong N-S to NNE-SSW alignment, and lesser NW-SE and NE-SW trends. All these are superimposed on pervasive, closely spaced, NNE-SSW and NNW-SSE lineaments present over most of the hilly parts of the map area. There are few major E-W aligned features. Some alignment trends correspond to strike directions of veins in the epithermal gold-silver deposits of the region, but none of the known mineralised structures were visible on the remote sensing data.   The volcanic rocks are Late Cenozoic in age and include a variety of rock types: andesite and dacite flows, domes and tuff breccias, rhyolite domes, tuffs and tephra, lacustrine siltstones, and ignimbrites. Mapping of different textures in the SAR image failed to provide additional information on rock types to that derived from the Landsat and SPOT images. A simple discrimination of rock units based on radar texture is apparently prevented by the complex volcanic geology, superimposed hydrothermal alteration, and long period of erosion.

Jan 1, 1994

Gold mineralisation at the Macraes Gold Project is hosted in the Hyde-Macraes shear zone and can be traced for ~30 km along strike, although economic resources are confined to a seven kilometre section in the vicinity of the Macraes  township. The shear zone, which typically dips at a low angle (~20¦) to the NE, is bounded by an upper hanging wall shear and a lower footwall fault. Mineralisation occurs along the hangingwall of the shear zone as well as in low angle concordant shears and stockworks. Ore types include graphitic cataclasites with variable amounts of quartz veining, 'lode schists' and quartz-vein stockworks. Mine geology and grade control activities are designed to ensure accurate definition of ore and waste as well as the accurate prediction of ore grade. Grade control involves an integrated process of blast hole sampling, geological mapping and geostatistical modelling. Geological mapping is carried out post blasting by means of excavating trenches across are zones defined by assay data. Conditional Simulation is used to model raw assay data to define ore-waste contacts and estimate ore block grade, although, geologically defined contacts have precedence. Low angle ore zones impart a wedge shaped geometry to many ore blocks. These ore blocks are bounded by contacts that can be selectively mined to, thereby reducing misallocation of ore and minimising grade dilution.

Jan 1, 2001

The transition from exploration to feasibility is a stage in the development of mineral resource projects that is frequently not handled well. The transition marks a point in the project development process where resource evaluation priorities change significantly from the discovery of mineralisation and the rapid assessment of the potential tenor of the mineralised system, to the detailed assessment of the deposit.   Information used in the exploration process tends to be of a qualitative or theoretical nature initially, but gradually becomes more quantitative in character as geological knowledge relating to individual prospects grows.   The transition from discovery and rapid exploration of a new deposit occurs at a relatively early stage in project development, coinciding with the first attempt to prepare a resource estimate for the deposit. Fundamental assumptions regarding both structural and grade continuity and uncertainty inherent in existing information need to be made so that they themselves may be addressed during the collection of additional data.   The effective commencement of feasibility studies involve the introduction of new accountabilities either as a result of appointment of a project manager, and through needing to be able to quantify: ò     the quality of data being collected for resource evaluation purposes; ò     confidence associated with resource estimates; and ò     the need to develop an audit trail for the project, required to make the resource evaluation decision-making process as transparent as possible.   Quality assurance is a concept to which exploration geologists have frequently had little exposure. Being able to demonstrate the quality of data used in feasibility studies is, however, a crucial component of the overall risk management and reduction.   Development of a transparent audit trail for data assists in demonstrating the quality of data which is frequently perceived to translate directly to confidence inherent in resource estimates.   Establishing procedures for geological data collection and management also provides a more reliable framework for making decisions that impact on project execution, again resulting in improved confidence in resource estimates and associated geoscientific data.   Regular, independent technical audits, in principle similar to audits conducted for the ongoing certification of standards compliant quality assurance systems, are a major, positive factor in effective project management and execution.   Information used in project evaluation, feasibility and development must be based on facts. Facts are effectively observations that are ideally made systematically, recorded in a systematic manner, and by being collected effectively are not subject to change.   Effectively managing the transition from exploration to resource evaluation, feasibility and project development involves recognising the nature of changes in the nature, detail and scope of geoscientific data required at each stage of project development. In doing so it is essential to: ò     recognise when the change occurs (as early as preparation of the initial resource estimate for a project); ò     accept that the change may not be gradual; and, ò     ensure that the project evaluation team is adequately resourced.   These objectives require recognition of the value of previous experience and the need to instill a true team approach amongst both staff and contractors associated with the project. Regular formal and informal communications between staff, contractors and other stakeholders in the project are an essential tool in ensuring personnel are aware of factors affecting their role in the project.

Jan 1, 2004

By W Valery, S Morrell

In the mining industry blasts are usually designed to fracture the in situ rock mass and prepare it for excavation and subsequent transport. The run of mine (ROM) fragmentation is considered good when it is fine enough and loose enough to ensure efficient digging and loading operations. Mining optimisation strategy is hence usually focussed on minimising total mining costs and maintaining these ROM fragmentation characteristics. Although this approach ensures an efficient mining operation it ignores the potential impact on crushing and grinding. Investigations by several researchers have shown that designing blasts to produce ROM fragmentation to optimise crushing and grinding performance enhances the overall efficiency and profitability (Eloranta, 1995; Kojovic et al, 1995; Bulow et al, 1998; Kanchibotla et al, 1998; Scott et al, 1998; Simkus and Dance, 1998). Field experimentation in this area is often found to be difficult because of high implementation costs and insufficient understanding about the effect of fragmentation at different stages in a comminution circuit. Modelling and simulation of blasting and comminution processes provide a more economic alternative to explore the impact of blast design changes on the down stream operations (Kanchibotla et al, 1998; Kojovic et al, 1998; Adam and Siddall, 1998; Bulow et al, 1998). However, the reliability of such simulations depends on:the ability of the models to reproduce the physical processes that take place; characterisation of rock mass in terms of its blastability and comminution characteristics; and in the case of blast modelling the ability to predict fines (-10 mm) has been found to be particularly important as this fraction has a significant effect on mill throughput.

Jan 1, 1999

Recent legislation in the environmental field gives the mining industry an opportunity to take timely action to address its image. Shifting the focus away from mining (the activity) to minerals (the resource) will enable the mining industry to stand on equal footing with other industries and will help minimise the vulnerability to political and interest groupsÆ interference.

Jan 1, 1993

Low displacement fault zones often comprise a mesh of interlinked faults, extensional-shear and purely extensional vein fractures. Hydrothermal mineralisation localised around such structures testifies to their importance as conduits for fluid flow. Mesh structures are most commonly developed in situations approximating bulk pure shear but predominantly simple shear meshes also occur. They appear to develop through the infiltration of pressurised fluids into a heterogeneous rock mass with varying material properties. In some circumstances, mesh formation appears to be a precursor to the development of major through going faults. Mesh formation generally involves hydrofracturing (Pf > s3, at least locally) and the condition Pf ~ s3 to be maintained for the mesh to remain a high permeability conduit, requiring fluid over pressuring at other than shallow depths in extensional-transtensional regimes. The volumetric character of earthquake swarm activity appears to result from the passage of hydrothermal fluids through mesh structures, representing a form of distributed fault-valve action along suprahydrostatic hydraulic gradients arising from magmatic intrusion, compaction overpressuring, metamorphic dewatering, etc. Fluid redistribution in the crust is influenced by maximum hydraulic gradient (not necessarily vertical), by existing permeability anisotropy arising from bedding and other forms of crustal layering, and by structural permeability developed under the prevailing stress field. Strong directional permeability develops in the s2 direction, parallel to fault-fracture intersections within the mesh and orthogonal to fault slip vectors. In particular tectonic settings, stress-controlled permeability allows strongly focused flow through fault-fracture meshes with high potential for mineralisation. Favoured localities for mesh development include short-lived link structures along large-displacement fault zones such as dilational jogs, lateral ramps, and transfer faults.

Jan 1, 1995

Old Copper Flotation Tailings Waste Reprocessing

Sep 13, 2010

By G Stanway, P Mahoney, C Griebel

The Mining Innovation – State of Play was initiated three years ago by VCI in partnership with the University of Western Australia. The ambition was to create a ‘think tank’ type platform to support industry discussion on how it is performing in terms of innovation at a strategic level, what needs to change in the industry ‘ecosystem’, and how businesses may more effectively develop their strategy and architecture to innovate for competitive advantage.The drivers for this ambition were straightforward. The industry recognises itself as being conservative with respect to innovation and it knows the business and community endowment dividend from getting better at innovation is large; however, much of the material that seeks to provide insight on innovation tends to be drawn from industries that do not have the same high capital, long life cycle and market uncertainty characteristics as that faced by mining. Material that does focus on mining innovation is orientated towards technical innovation, not innovation strategy. There exists a significant knowledge gap, and filling it is valuable to both mining businesses and communities.The 2014 Mining Innovation State of Play report (Stanway, Griebel and Mahoney, 2014), based on a survey of over 230 mining executives, uncovered a range of insights but left several questions unresolved. The people with the best perspective on these questions are CEOs. They can see the business issues with sufficient clarity and have the influence to shape both the industry and its organisations, as seen in Figure 1. Discussing these questions with the view to progressing our collective understanding was the primary reason this interview series was conducted.Unsurprisingly, interviewing 15 CEOs and Chairpersons from different industries and commodities, across the globe resulted in a broad range of views. The discussions were frank and often blunt in assessing the short comings in the industry and suggestions for improvement. This degree of candour is hugely valuable as a basis for improvement. In the end, four key areas emerged as a basis for improvement.CITATION:Stanway, G, Griebel, C and Mahoney, P, 2017. Mining Innovation State of PlayTM – iron ore insights, in Proceedings Iron Ore 2017, pp 439–442 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Efficacy of Enhanced Gravity Separator in Processing Indian Iron Ore Slime The slime sample was subjected to concentration using Falcon concentrator for their enrichment. The effects of three important variables, eg bowl rotation frequency, back water flow rate and per cent solid were studied on the process performance. Increasing the rotation of the Falcon bowl, enable more material to the underflow by increasing the yield, whereas, the iron content decreases steadily with increasing the rotation of the bowl. The increase in the back water flow effectively removes the clay materials from the underflow at the expense of the yield. Similarly, increasing the per cent solid concentration in the feed produces a better product both in terms of yield and Fe content. Results show that EGS/Falcon can be used for processing Indian iron ore slime and producing pellet grade concentrate.

Sep 13, 2010

Methods for Improving the Flotation Recovery of the Coarse Fraction of a Nickel Ore

Sep 13, 2010

Mining companies in order to compete and succeed in being viable business propositions must look to the future and select mining methods which guarantee improved efficiency and productivity as well as lower costs. A mining company in adopting a method of mining must now select the equipment most compatible. To some mines compatible equipment may mean the use of drilling jumbos to replace hand held rock drills or the use of load haul dump units to replace scrapers. To other more mechanised mines compatible equipment may mean the use of raise borers and road heading machines. The right decision will be where equipment compliments method in such a way that the working environment is improved, productivity is maximised, cost if reduced and all profit opportunities are optimised. An example of such is where the use of improved mining techniques in underground operations may see cut off grades reduced. By selectively mining these lower grade orebodies, smaller operation's ore reserves improve and the capacity for continued growth is enhanced.

Jan 1, 1990