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Centrifugation is a technique used for the separation of particles from a solution according to their size, shape, density, viscosity of the medium and rotor speed. The particles are suspended in a liquid medium and placed in a centrifuge tube. The tube is then placed in a rotor and spun at a define speed. Separation through sedimentation could be done naturally with the earth gravity, nevertheless, it would take ages. Centrifugation is making that natural process much faster. Rotation of the rotor about a central axis generates a centrifugal force upon the particles in the suspension. Which factors have an influence on centrifugation : Density of both samples and solution Temperature/viscosity Distance of particles displacement Rotation speed
In order to accelerate the gravitational settling and floating of crystals in silicate liquids at high temperatures we have built a furnace which operates at 1200 °C while being rotated in a centrifuge at 2200 RPM. The heating element is constructed of Kanthal wire wound around a 14.5 mm ID mullite tube and the temperature is controlled and measured by two Pt–10 Rh thermocouples. The power and thermocouple circuits are connected, through a slip-ring assembly mounted on the centrifuge shaft, to a temperature controller and potentiometer.The rotation of the furnace and experimental charges produces a gravitational force 700 times that of earth gravity (g). This increases the settling and floating rates for crystals or immiscible liquids by a factor of 700 over the rates at 1 g. A 1-h run in the centrifuge is thus dynamically equivalent to a 1-mo run at 1 g. Preliminary experiments with basaltic liquids containing olivine, pyroxene, plagioclase, and magnetite crystals are described.