A filter with a suitable filtering material; special paper, textile, sintered glass or ceramics, bed of kieselgur, etc. Sometimes the filtering is under pressure or vacuum.
… Another AnswerEvery filtration method requires two fundamental things: An apparatus to perform the filtration, and directed energy to drive the filtration process. There are uncountably numerous ways to do this. The best method(s) to filter a mixture is determined by the chemical and physical properties of each substance in the mixture. The general process is to find something that will affect one component of the mixture, but not another(s). This could be applying enough heat to boil one substance but not the other (EX distilling salt water), passing the mixture through a membrane that is only permeable to one substance (EX a coffee filter), adding a chemical which will react with one substance to make it precipitate (EX adding Sodium Carbonate to a solution of Calcium Nitrate to make it precipitate into Calcium Carbonate) and many more. (MORE) 
