http://www.hindawi.comThe latest articles from Hindawi Publishing Corporation© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/2009/817135.htmlFluid flow and charge transport in fine structures can be driven both by pressure gradients and by electric fields if electrochemical double layers are present on the surfaces. The interrelated electrohydrodynamic effects may be used to drive liquids without moving parts, for example, in dewatering or in electroosmotic chromatography, or to generate small electric currents. While the electrohydrodynamic transport is well understood for simple geometries, models for porous structures are complex. Furthermore, the interconnected porous structure of a packed bed itself strongly depends on the electrochemical double layers. In this study, the electrohydrodynamic transport in packed beds consisting of boehmite particles with an average diameter of 38 nm is investigated. We describe a new approach to the electrokinetic effects by treating the packed beds as theoretical sets of cylindrical capillaries. The charge transport and the electrically driven fluid flow predicted with this model agree well with experimental results. Furthermore, the hydraulic permeability was found to be a nonlinear function of the porosity, independent of whether the porosity change is caused by changing the compression or the electrochemical double layer.Bastian Schaefer and Hermann Nirschl© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/2008/508617.htmlRotating disks separators, mounted on single and double hollow shafts, are investigated experimentally. The shaft and disks were enclosed in stainless steel housing. Many parameters were measured to study their influence on the performance of single and double shaft disk filters at various rotation speeds. These parameters are pressure inside the housing, permeate flux, and electrical power consumption. The average velocity coefficient k˜ for single and double shaft disk separators was estimated and was found to be a good criterion of module performance as well. The comparison of measured and calculated filtration flow rate at various rotation speeds was in a good agreement. The estimated average shear stress is found to be about twice in double shaft filter disk. The feasibility of double shaft disk separator in treating filtration without filter cake is highly appreciated.Yazan Taamneh and Siegfried Ripperger© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/2007/091740.abs.htmlSedimentation of organic fibres and inorganic particles can be observed in several industrial applications. Fibres are involved not only in wastewater treatment but also in other separation applications. In the paper industry, the separation of inorganic filler and coating particles from short cellulose fibres is still a challenge in the recycling process. During that process, particles have to be removed to obtain a purified fibre suspension. These fibres can be used again to produce new paper. With the currently applied techniques, like screening and flotation, the efficiency of short fibre separation is very poor. Moreover, also separation by sedimentation fails due to similar settling velocities of heavy-small particles and the light and larger fibres. This paper concentrates on the sedimentation of organic fibres and inorganic particles in water. The investigated suspensions are made by resolving two different and specially produced papers a coated and an uncoated one, as well as the single components used for its production. We observe a different sedimentation behaviour according to the concentration of fibres and particles in the suspension and the pH-value of it. The main result is that, according to the fibre rate, the sedimentation behaviour is particle dominant or fibre dominant.Markus Feist, Hermann Nirschl, Jörg Wagner, Georg Hirsch, and Samuel Schabel© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/2007/034832.abs.htmlThe study presents the transfer of nanoparticles from the aqueous phase to the second nonmiscible nonaqueous liquid phase. The transfer is based on the sedimentation of the dispersed particles through a liquid-liquid interface. First, the colloidal aqueous dispersion is destabilised to flocculate the particles. The agglomeration is reversible and the flocs are large enough to sediment in a centrifugal field. The aqueous dispersion is laminated above the receiving organic liquid phase. When the particles start to penetrate into the liquid-liquid interface, the particle surface is covered with the stabilising surfactant. The sorption of the surfactant onto the surface of the primary particles leads to the disintegration of the flocs. This phase transfer process allows for a very low surfactant concentration within the receiving organic liquid, which is important for further application, that is, synthesis for polymer-nanocomposite materials. Furthermore, the phase transfer of the nanoparticles shows a high efficiency up to 100% yield. The particle size within the organosol corresponds to the primary particle size of the nanoparticles. Stefanie Machunsky and Urs Alexander Peuker© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/2007/070376.abs.htmlScreen bowl centrifugation process is widely used for fine coal dewatering due to its relatively low cost, high capacity of providing low-moisture content product as well as relative ease of operation and maintenance. However, screen bowl centrifuge tends to lose a significant amount of ultrafine clean coal to the main effluent and screen-drain streams. This study aims at obtaining a better understanding of the parameter main effects and interaction effects with an ultimate goal of improving the dewatering performance of a screen bowl centrifuge. A three-level factorial experimental design has been utilized to conduct a test program using a continuously operated screen bowl centrifuge having a bowl diameter of 0.5 meter. The results of this study indicate that moisture content of the clean coal product is affected by both feed solid content and the pool depth maintained in the centrifuge. On the other hand, clean coal recovery to the product launder was found to be a function of feed solid content and volumetric feed flow rate but independent of the pool depth. The interaction effect of feed flow rate and feed solid content also appeared to have a significant effect on the clean coal recovery.Manoj K. Mohanty© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/2007/028908.abs.htmlThe Rayleigh‐Taylor instability of a Newtonian viscous fluid overlying an Oldroydian viscoelastic fluid containing suspended particles is considered. As in both Newtonian viscous-viscous fluids, the system is stable in the potentially stable case and unstable in the potentially unstable case, this holds for the present problem also. The effect of a variable horizontal magnetic field is also considered. The presence of magnetic field stabilizes a certain wavenumber band, whereas the system is unstable for all wavenumbers in the absence of the magnetic field for the potentially unstable arrangement.Pardeep Kumar and Mahinder Singh© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/2007/048238.abs.htmlThis paper presents a model of the separation process in a ferrohydrostatic separator (FHS) which has been designed and developed at DBGS, De Beers, South Africa. The model was developed using special discrete element method software package called Particle Flow Code in 3D (PFC3D). Special attention has been paid to the selection of the simulation parameters in order to achieve the required feed rates. The simulation was carried out using spherical particles and density tracers of different sizes and densities ranging between 0.004 and 0.008 m and 2700 and 3800 kg/m3, respectively. The tracers were used to set the apparent density of the ferrofluid (the cut-point) and to provide a measurement of the efficiency of the separation. The model is replacing the ferrofluid by imposing a drag force on the particle. The results of the simulation were presented in the form of the distribution of the density tracers into the sink fraction. These results are realistic and show the advantages of DEM to understand the complex flow behavior of granular materials.V. Murariu and P. J. Sergeant© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1983/012382.abs.html© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1985/013627.abs.htmlThe construction and principle of operation of a new magnetic separator for volatile dust is described. The results, obtained on a model separator in laboratory conditions are discussed.E. A. Mendrela, K. Adamiak, and E. M. Mendrela© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1983/015945.abs.html© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1985/017201.abs.htmlThe use of magnetic separators in the various mineral processing facilities in South Africa is described. A large number are used to recover medium in dense medium plants. The manufacture of various types of magnetic separation machines by three local suppliers is highlighted. The potential use of highgradient and/or high–intensity magnetic separation in the recovery of gold, uranium, and phosphate minerals is discussed.Ian James Corrans and Jan Svoboda© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1983/019518.abs.htmlMagnetohydrodynamical separation has been developed in the eastern bloc with apparent success but has largely been ignored by western science. Here a simple, theoretical examination of the technique is undertaken and its potential for particle separation is demonstrated to a degree that poses the question – why has this technique not been fully explored in the west?Derrick Fletcher© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1983/024190.abs.htmlIn this short communication it is shown that it is possible to undertake inexpensive but useful preliminary mineral studies using single–wire HGMS. Such studies enable an assessment to be made of the viability of HGMS as a large-scale processing technique for particular mineral slurries.J. H. P. Watson, A. S. Bahaj, and D. Rassi© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1984/027852.abs.html© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1984/031525.abs.html© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1984/036097.abs.html© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1984/039671.abs.htmlA survey of magnetic separation research at FDO Engineering consultants, the University of Nijmegen, and the Energy Research Foundation (ECN) will be given.C. B. W. Kerkdijk, R. P. A. R. van Kleef, and J. A. Roeterdink© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1984/043434.abs.html© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1984/048016.abs.htmlA mathematical model to describe the macroscopic behaviour of an axial magnetic filter is developed. The model takes into account the long range of absorption forces. Partial mixing of the particles in the fluid is included by introducing the concept of “mixing length”. Behaviour of an axial filter under different conditions is numerically simulated. Experiments with colloidal ferrite particles indicate that for an axial filter composed of 12 μm steel wires with a packing factor of 4.8% the mixing length is of the order of 4 mm.H. K. Collan, M. A. Kokkala, and O. E. Toikka© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1985/051678.abs.html© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1983/053985.abs.html© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1985/056250.abs.html© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1983/058568.abs.htmlMagnetic microparticles with reactive surfaces can be used to rapidly remove soluble and insoluble materials from water with the aid of novel contacting systems. This paper reviews work on the development of a new process, which uses specially pretreated finely divided particles of magnetite to remove colloidal material from a raw water. This process has now reached the commercial stage, with the design, construction and operation of a 35 M1/day demonstration plant.A. J. Priestley© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1985/059814.abs.htmlMagnetic separation facilities and research activities in Zambia are described.Jacobus N. M. Agricola© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1983/062341.abs.htmlResearch and development, manufacturing and industrial applications of magnetic separation in Finland are reviewed.Matti Kokkala and Tor Meinander© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1983/065904.abs.html© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1983/070576.abs.html© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1984/074149.abs.htmlHighly successful tests have shown that high gradient magnetic filtration can provide a viable alternative to conventional filtration to curb the amount of stack gas particulate emissions from iron-based industries, especially steelmaking processes. Using basic oxygen furnace dust in our work at Sheffield University, filtration efficiencies of 99% and greater were obtained for submicron particles down to an optically measurable 0.24 μm diameter; for particles of 1 μm and above, 100% filtration efficiency was achieved. High gas throughput, together with low pressure losses, low applied magnetic fields and good filter matrix loadability all further indicate the potential commercial practicality of HGMF in the steelmaking industry.Aik Chong Lua and Robert F. Boucher© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1984/078713.abs.htmlA technique for the removal of tumour cells from bone marrow is described. This involves rendering the tumour cells ‘magnetic’ by attaching them to magnetite–containing microspheres by a double layer of antibody. Bone marrow conraining these ‘magnetic’ tumour cells is then passed through a system of magnets so that the tumour cells are drawn out of the bone marrow. Treated bone marrow may then be reinfused into the patient from which it was taken.Jennifer G. Treleaven, Frances M. Gibson, John Ugelstad, Alan Rembau, and John T. Keshead© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/psse/1984/082484.abs.htmlIn excess oxvgen, 0-37 μm CuFeS2 became magnetic at a temperature of 280ºc. The magnetic product is copper ferrite, CuO.Fe203. The ‘magnetizing’ temperature increased with particle size apparently following the trend reported for the ignition temperature. Dilution increased the magnetizing temperature; 80% dilution by PbS, MoS2 or SiO2 increases the temperature from 280ºC to over 420ºC. Sinterina was a concurrent reaction. Nevertheless, a chalcopyrite/ galena mixture after roasting and gentle grinding was readily separated on a Davis tube.Irina Makarow, Thomas Agrafiotis, and James A. Finch© 2010, Hindawi Publishing Corporation. All rights reserved.