A centrifuge is a device that rotates an object to apply centrifugal force perpendicular to the axis of rotation. Modern centrifuges are driven by an electric motor, but older models needed to be spun by hand. They are commonly used in the laboratory to separate heavier particles in a solution. Centrifuges also use this principle to enrich uranium. Centrifuges also have a number of commercial applications, such as a clothes dryer.
Use a simple laboratory centrifuge to isolate and separate suspensions. These centrifuges typically consist of a central rotor that has a number of wells for holding test tubes or some other container.
Place the test tubes in the centrifuge. Some models will require you to load test tubes with water to keep the centrifuge balanced. The rotor will begin to spin rapidly when you turn on the centrifuge.
Allow the centrifuge to produce sediment. The particles in the solution will move along the direction of the centrifugal force toward the bottom of the tube. The heavier particles will move faster and will therefore settle out of the solution first.
Enrich uranium with a gas centrifuge. Place uranium in a centrifuge that contains uranium hexafluoride gas and spin the centrifuge. The heavier isotope of uranium 238 will tend to accumulate on the walls of the centrifuge. The lighter uranium 235 will be more concentrated in the center of the centrifuge.
Extract the uranium from the center of the centrifuge to get uranium that's higher in uranium 235. Repeat this process many thousands of times to obtain uranium that has a higher than normal concentration of uranium 235. Enriched uranium is used to make nuclear reactors and nuclear bombs.