How would one separate solid barium sulfate from an aqueous solution?

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ncchemist | eNotes Employee

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Barium sulfate is an inorganic salt that is completely insoluble in water.  It is used as a radiocontrast agent in medical imaging tests since it absorbs x-rays better than human tissues.  When mixed with water, barium sulfate forms a heterogeneous mixture since it doesn't dissolve.  Specifically, the solid particles form a suspension in the water.  The solid is easy to separate from the water a couple of different ways.  You could put the mixture in a centrifuge.  The solid would be pressed down to the bottom of the tube and the water could simply be poured off the top.  You could also pass the suspension through a paper filter using vacuum suction pressure.  The water will pass through the paper and the solid will be collected in the paper filter.