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Phosphorus Phase Analysis of Medium-Low-Grade Rare-Earths-Bearing Phosphate Ores

Sep 13, 2010

A model has been developed for drum scrubbing which allows selection of geometry and power input. Specific aspects considered are: Calculation of total static and operating volumes. Total residence time based on total operating volume. Solids residence time based on solids operating volume. Selection of the aspect ratio. Alteration of operating fill to allow for smaller or larger feed openings. Selection of proportion of critical speed. Calculation of shell and motor power requirements. The model uses either solids or total residence time to calculate the required operating volume. The solids residence time is based on the proportion of coarse solids in the feed. Material finer than the reject size is considered as part of the slurry. The solids operating volume is the static volume plus the surcharge on the discharge weir required for flow of the solids from the unit. The total operating volume is the static volume plus the surcharge on the discharge weir for the total flow to exit the scrubber. The burden density is calculated from the coarse solids bulk density and the slurry density that includes all the fine solids. Power is calculated using the Liddell and Moys correlations for burden position and shape, and the operating rotational speed. Results from the model (especially power) have been verified from industrial installations of significant size. Predicted and observed power draws are within two per cent. A check against the JKMRC mill model shows power draw prediction agreement to within four per cent.

Jan 1, 2004

The Ekati Diamond Mine is located on permafrost terrain in CanadaÆs Northwest Territories. The mine rock consists of: diamond-bearing and barren kimberlite; and surrounding waste rock such as granite. The kimberlite occurs in several vertical æpipesÆ that are, or will be, mined using open pits. Early predictions of drainage chemistry at Ekati identified the potential for ARD due to sulfide oxidation from both waste rock and kimberlite. This was surprising for the kimberlite, because neutralisation potentials (NP) are typically hundreds of kg CaCO3 equivalent/t. However, subsequent testwork showed that substantial portions of the NP ædisappearedÆ quickly, apparently due to the unusual non-carbonate mineralogy. In any case, additional predictive work concluded much of the rock was benign and there would be no ARD. Shortly after mining started, ARD appeared from both the waste rock and kimberlite, although a few years passed before the company and its consultants recognised that at least some of the acidic water was ARD. Numerous other processes have been put forward as possible explanations for the remaining acidic drainage, although none have been either confirmed or eliminated. Because: the causes of the ARD and acidity are not known; no causes have been eliminated and more have been added; drainage chemistry was not predicted accurately; and future mining will encounter similar rock. I believe the Ekati Diamond Mine needs high-level assistance to understand current chemistry and to avoid problems with future drainage. Organisations like INAP, MEND3, and universities could provide this assistance.

Jan 1, 2003

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 Tuck M. A

The increasing depth, mechanisation and distance of working areas from surface connections places an ever greater contaminant burden on ventilation airflows. Some British Coal mines are already experiencing significant problems in providing adequate climatic conditions in the working areas and have had to introduce air conditioning. Previous work has shown that in mines of low to moderate virgin strata temperature the application of controlled district recirculation could serve to improve climatic conditions at the working area.

Jan 1, 1988

Removal of Arsenic in Fluorite Ore by Simultaneous Grinding-Leaching with NaHS Generally speaking, a high-grade fluorite ore is converted into hydrogen fluoride (HF), which is essential for the semiconductor manufacturing. With the continuous depletion of resources, novel technologies for processing low-grade fluorite ores are urgently needed, in order to lower the arsenic concentration to less than 100 mg/kg. In this study, a low-grade fluorite ore was upgraded by removing arsenic, which is difficult to remove by conventional method. The mechano-chemical leaching of fluorite ore (i.e. the sample was ground in presence of NaHS, using a beads mill) was carried out to investigate the removal of arsenic from the low-grade fluorite. Experimental results showed that the arsenic concentration was reduced to 73.2 mg/kg.

Sep 13, 2010

Enhancement of Energy Efficiency in Fine Grinding of Copper Sulfide Minerals Using a Pilot-Scale Stirred Media Mill - IsaMill The mineral liberation size of run of mine ores has dramatically reduced over recent years. As a result, the demand for fine grinding which is the most energy-intensive form of grinding has markedly increased in the minerals industry. Furthermore, the fine grinding costs increase exponentially with decreasing product particle size. As a result of the increased energy requirement for fine grinding, it is desirable to optimise fine grinding processes such as stirred media milling (ie IsaMill) to enhance energy efficiency, throughput and the product fineness. In the present study, the influence of slurry rheology, grinding media type and grinding media-to-feed size ratio on energy efficiency in a pilot-scale IsaMill was investigated under certain industrially relevant pulp processing conditions. It was shown that a critical rheological state existed, below which the energy required to achieve an 80 per cent passing (ie P80) 20 ¦m product size was unaffected by shear rheology (ie apparent viscosity and shear yield stress) whilst above which the grinding energy required increased dramatically with increasing shear rheology. Colorado River sand (3.35 mm) showed higher energy efficiency than MT1 ceramic media (2.5 mm) for a target P80 of 20 ¦m in the solids concentration range of 38 to 55 per cent by weight, but the former experienced more than four times the wear rate of the later. The high wear rate of the Colorado River sand may be due to its much lower hardness. For feeds with an 80 per cent passing (ie F80) 70 to 110 ¦m, 2.0 or 2.5 mm MT1 media appeared to be more energy efficient than 3.5 mm MT1 media whilst a media-to-feed size ratio of 41 to 53 is applicable for ~50 ¦m (ie F80) feeds for efficient grinding.

Sep 13, 2010

By M Watts, P Lindsay

Herbert Stream, a tributary of the Waimangaroa River on the Stockton Plateau, has elevated metal concentrations and low pH characteristic of acid mine drainage (AMD). Dissolved aluminium concentrations average 8.3 ppm, iron 1.4 ppm, manganese 0.69 ppm, and zinc 0.12 ppm and pH ranges from 2.8 to 3.2. Flow rates range from 2.3 to 26.6 L/s with an average of 5.3 L/s. To determine the effectiveness of different treatment strategies, a small amount of the AMD was diverted through three small-scale passive AMD remediation systems over an eight month period. These included a reducing and alkalinity producing system (RAPS), a limestone leaching bed (LLB), and an open limestone channel (OLC). Both the RAPS and the LLB performed well, effectively removing metals and restoring pH. The RAPS lowered aluminium concentrations by up to 99%, iron 97%, manganese 95%, and zinc 80% and the LLB lowered aluminium concentrations by up to 99%, iron 99%, manganese 92%, and zinc 91%. The pH was restored to between 6.4 and 7.4 by the RAPS and to between 7.3 and 7.9 by the LLB. The OLC performed well as long as the residence time was similar to that of the other treatment systems. OLC removal rates for aluminium was up to 99%, iron 94%, and manganese 21%, and the pH was restored up to 5.6. Due to its simplicity and effectiveness, it is proposed the LLB be constructed to fullscale size to treat the entire Herbert Stream.

Jan 1, 2007

By B Powell

Coastal acid sulfate soils (ASS) are wetland soils and unconsolidated sediments that contain iron sulfides which, when exposed to atmospheric oxygen in the presence of water, form sulfuric acid. ASS form in protected low energy environments such as barrier estuaries and coastal lakes and commonly occur in low lying coastal lands as Holocene marine muds and sands. When disturbed, the iron sulfides in these soils can oxidise and produce large volumes of sulfuric acid (essentially similar chemistry to acid rock drainage with mines) resulting in the subsequent release of toxic levels of iron, aluminium, manganese and possibly heavy metals. This results in detrimental effects on aquatic biota, plants, animals and steel/concrete structures and on human health in the surrounding environment. There are an estimated 2.3 million ha of ASS located along 6500 km of the Queensland coastline. In contrast to many mineral sulfides encountered in the mining industry, the pyrite crystals in ASS can be as small as 2 mm and commonly occur as framboids with extremely large surface area per unit mass, substantially increasing their reactivity if exposed to air (oxidation). Highly reactive iron monosulfides can also occur, particularly in drains and shallow lakes. Many coastal areas, where some 80 per cent of the population of Queensland reside, are coming under pressure for agricultural and urban development. Construction of canal estates, marinas, housing/industrial estates, roads, golf courses, aquaculture ponds, sand/gravel extraction and drainage for sugar cane can disturb ASS and release sulfuric acid, which may then drain into adjacent waterways with heavy rain. As development continues to encroach on coastal lowlands, the identification, quantification and management of ASS must be addressed as part of a commitment to the principles of Ecologically Sustainable Development (ESD). ASS can be successfully managed by adopting best practices and following guidelines, but government, community and industry must collaborate to raise awareness, avoid æhot spotsÆ and develop more cost-effective solutions. Scientists led the education and public awareness program showing infrastructure and environmental damages arising from ASS in Queensland. Using results from mapping and research, they convinced policy makers, industry and polititians to accept the need for legislation founded on good science. The resulting æState Planning Policy 2/02: Planning and Managing Development Involving Acid Sulfate SoilsÆ identifies the StateÆs interest in acid sulfate soils. The Queensland Government considers that development involving acid sulfate soils in low-lying coastal areas should be planned and managed to avoid potential adverse effects on the natural and built environment (including infrastructure) and human health. SPP 2/02 states where the policy applies and when a development application will trigger the policy. It can also be used to assist local governments in preparing their planning schemes under the æIntegrated Planning Act 1997Æ. The SPP 2/02 comes with a æState Planning Policy 2/02 GuidelineÆ to provide advice and technical information on interpreting and implementing the SPP 2/02. This guideline has legal status in assisting in the interpretation of SPP 2/02. Those seeking more detailed technical information can now also access the æSoil Management GuidelinesÆ and ASS æSampling GuidelineÆ, available from the Department of Natural Resources and Mines website. These are some of a series of chapters being developed for the æQueensland Acid Sulfate Soil Technical ManualÆ.

Jan 1, 2003

Mineral formations, accumulated during technogenic activities greatly influence an economic and ecological situation in the Kola North. On the one hand, the dumps from extraction of mineral resources, tailing ponds of beneficating plants, ash dumps, wastes of metallurgical and mechanical engineering productions destroy the regionÆs environment and require taking certain measures and costs to bury or protect from weathering, oxidation, etc. On the other hand, technogenic mineral formations contain a lot of valuable scarce components. The amount of solid wastes increases annually, causing damage to ecology and economy. Researches conducted in recent years showed a possibility and economic expediency of comprehensive processing of wastes from different enterprises in Murmansk region and their use for production of new competitive commodity output, possessing high consumer properties. Thus, involving mineral wastes from Khibiny apatite deposits into hydrometallurgical industrial processing provides the basis for setting up a large beneficating-metallurgical complex. In this case ores and wastes from other deposits on the Kola Peninsula, containing titanium, rare, rare-earth and other valuable elements, may be involved into processing. Establishing such a complex will allow to organise a deep processing of natural resources, utilise some production wastes, improve ecological security and supply production with competitive output. Expanding the complex implies not only involving new mineral raw material into processing, but mainly deepening raw material processing, maximum utilisation of local natural resources and obtaining a wider variety of prime products.

Jan 1, 2002

A search for the keyword nano reveals that it has not made a significant entry into the mineral processing research literature. In contrast, the terms micelle, colloid, interface, and monolayer are well established there. By considering nanoscience as colloid and interface science at the nanoscale, it is claimed that several previous and current investigations in the broad field of mineral processing fall under the umbrella of nanoscience. Several examples from hydrometallurgical processing systems (invisible gold and activated carbon in gold extraction; monolayers, reverse micelles, and microemulsions in solvent extraction; nanobiofilms and nanoparticles in biohydrometallurgy) are highlighted in support of this view.

Sep 13, 2010

By K P. Tully

In August 1996 a Microseismic Monitoring System developed by ISS International Limited was installed at the Pasminco Broken Hill Mine -Southern Cross area. The project aims were to:Assist in daily safety management in a mine environment which exhibits one of the highest occurrences of microseismic activity recorded in the Australian mining industry. Be used as a proactive tool in design of future development and stoping. The project to-date has been an unqualified success in achieving both goals. Consequently the system is being expanded from 6 to 14 monitoring sites.

Jan 1, 1998

By J Samosir, L Snyman

Northparkes was the first mine in Australia to use block cave mining method which relies on gravity and natural rock stresses to fragment and recover the ore. It was also the first hard rock mine to use hydraulic fracturing, in conjunction with CSIRO, to promote caving of E26 Lift 1. The technique was later used on E26 Lift 2 wedge and E48 prior to undercutting.Northparkes production is currently sourced from the E48 Lift 1 block cave mine and E26SLC. The E48 block cave contains economic ore to the north and south of the current cave footprint. To recover this ore the footprint has been extended on the north and south with two extraction drives and one extraction drive, respectively. Modelling of cavability above the additional drives indicated that the cave would not readily propagate to a sufficient height of draw to mobilise the ore and tended to arch over into the existing cave. To address the modelling results and to reduce the risk of the project, rock mass preconditioning was adopted.This fracturing campaign was performed from surface drill holes adjacent the subsidence zone angled to intersect the higher grade and higher elevation ore zones.Optical televiewer surveys, run prior to fracturing, picked intervals and fault zones to be avoided. Holes were resurveyed post-fracturing to detect newly created fractures and as a measure of success of the program.During fracturing operations water and gel fractures were run at varying depths and pumping pressure was logged for each fracture. The mine seismic system monitored significant events and dye in the fluids utilised for tracking water inflow locations during underground inspections.Towards the end of the project, guar fibres from gel were detected within the mill circuit and required treatment to resume optimum processing.CITATION:Webster, S, Snyman, L and Samosir, J, 2016. Preconditioning E48 cave extension adjacent to an active cave, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 471–478 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By A Scott, I Onederra

A great deal of technical and research effort has been applied to the development of models to predict fragmentation from rock blasting. A number of quite useful empirical or engineering models are currently available to blasting engineers and consultants, while more sophisticated approaches using mechanistic and numerical descriptions of rock breakage continue to be developed and applied by researchers and explosives companies.The fragmentation resulting from any blast will be heavily dependent on the properties of the rock mass being blasted; however, most empirical models rely on ‘rock factors’ generated from simple rock mass properties to describe the influence of the rock on the blasting outcome. In contrast, mechanistic models need explicit rock mass properties that require sophisticated laboratory measurements and detailed structural data if realistic outcomes are to be generated. The fragmentation modeller is caught between excessively simple rock mass descriptions for the empirical models and excessively complex data requirements for the mechanistic models.This paper briefly reviews the basis of a range of fragmentation models and the rock mass properties on which they rely. Shortcomings in the way that the mining industry tends to characterise the blasting properties of rock are discussed and some practical approaches are described to quantify these properties in both operating and greenfield mining environments. Case studies are presented where specific additional breakage properties and modelling features have been needed to generate a useful description of the fragmentation achieved.CITATION:Scott, A and Onederra, I, 2015. Characterising rock mass properties for fragmentation modelling, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 149–160 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

A Simulation Study on Two-Stage Grinding with High-Pressure Roller Mills By the application of high-pressure roller mill (HPRM) in the field of mineral processing, computer simulation can be used to predict overall performance of a grinding circuit based on data obtained from HPRM comminution test in pilot scale or industrial scale. Using the model developed by Klymowsky and Liu for HPRM comminution and an extended Plitt's model for classification, steady-state of a closed circuit grinding can be calculated by means of a virtual locked-cycle-test conducted on computer. This paper presents the result of a simulation study on two-stage grinding with HPRM as the comminution device. The emphasis is put on the influences of circuit-configuration and way of recirculating classifier's coarse-product on the overall circuit performance. The results show that two-stage grinding with HPRM has its merit and flexibility in meeting demands of various grinding tasks in mineral processing.

Sep 13, 2010

By T Nassis, H M. Nel, T du Toit

Assmang Khumani Iron Ore Mine is exploiting the iron ore deposits that can be found in the Bruce-King-Mokaning farm areas in the Northern Cape, South Africa. The Bruce, King and Mokaning (Khumani) deposits are approximately 10 km south of the town Kathu, adjacent to the Sishen Mine. Assmang Limited is jointly owned and controlled by African Rainbow Minerals Limited and Assore Limited.Measurement, calculation and trending of plant throughput and chemical ore properties are critical in maintaining a successful beneficiation operation due to these values forming the basis of decision-making and thus promotion of efficient ore extraction. The Khumani management and engineering information system (MEIS) supplies information on key process parameters to an operational team and is required to do so within an optimal time frame, for maximum impact.Diverse data is put into the MEIS from multiple specialist systems, with interfaces that require manual intervention. Manual intervention is resource and time intensive to the point which limits the effect on the process and decreases the potential for value addition.Automation of interfaces decreases resource and time requirements, standardising plant wide data sources and providing the opportunity to provide specialist system data to decision-makers in a timely fashion, resulting in maximum impact on the process output.Engineering and metallurgical management systems were interfaced at Khumani Iron Mine by means of an automated table which facilitates the transfer of production data validated within the engineering system as input to the metal accounting system. This interface effectively assigns a master to each specialist data set employed for decision-making and delivers accurate process parameters to the production team within an optimal time frame, resulting in increased potential to improve beneficiation efficiency.CITATION:Nel, H M, Nassis, T and du Toit, T, 2013. The role of metallurgical and engineering information systems in the optimisation of iron ore beneficiation processes, in Proceedings Iron Ore 2013 , pp 453-458 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

Flotation of Smithsonite by Using Siloxane Cationic Surfactants as Collectors

Sep 13, 2010

The Main Seam occurs in two 'pods', termed North and South, separated by an east-west oriented 'want' zone (most probably a palaeo-channel). The seam on either side of the 'want' area reaches thicknesses of over 30 metres but the North Main Seam adjacent to the 'want' zone has been split into multiple seams of 10 to 15 m thickness. Rock types in the inter-burden of this area are characterised by inter-bedded sandstones and carbonaceous mudstones varying in thickness from 0.5 to 5 m. In the South Main Seam, an area of un-split coal exists and is characterised by few inorganic partings. Overburden in this area varies geographically from relatively thick mudstones in the south and east part of the coal deposit to inter-bedded sandstones and carbonaceous mudstones adjacent to the 'want' area. The sandstone/mudstone overburden probably represents a splay or splay-channel complex emanating from the larger 'want' area palaeo-channel. Modelling lithological variability is of use because it is one of the factors used in predicting cavability and roof support system design. The coal in both the north and south deposits were found to exhibit highly predictable quality and breakage parameters in relation to the coal geometry. Although ash yield and sulphur are mostly low and not variable, volatile matter and thus fixed carbon, varied in relation to seam thickness. In general, volatile matter (dat) decreased and moisture increased with decreasing seam thickness whereas moisture increased with decreasing seam thickness. In addition to these parameters it was found that the energy needed to crush the coal was lowest at the top and bottom of the seam and, on a whole seam basis, decreased with seam thickness. All of these parameters were found to vary in relation to the vitrain band content of the coal which itself was controlled by seam geometry. These parameters can therefore be modelled and inputted into mining plans and quality control operations.

Jan 1, 1996

Permitting, engineering and evaluation, detailed design and construction aspects of the Golden Cross goldmining project in New Zealand are briefly reviewed. The extremely lengthy and complicated governmental approval process together with the delaying tactics of opponents of the project are outlined and comment is made on aspects of the draft legislation proposed as part of the overhaul of New Zealand's resource management laws.

Jan 1, 1990

I am wearing two hats today. When the invitations went out to participate in this forum, two were received in the head office of the Department of Lands and Survey - one addressed to the Director-General of Lands and one to the Chairman of the National Parks Authority. It seemed logical that as the department is responsible to the Government for the administration of the National Parks Act 1952, we should respond by providing one speaker to cover both the department's interests and those of the National Parks Authority. I hope, however, that this will not blur the clear distinction which exists in the context of the mineral industry between Crown land on the one hand administered by the department for the statutory Land Settlement Board and national parks and allied reserves on the other hand which are the responsibility of the National Parks Authority.

Jan 1, 1976