An apparatus and method of separation of LOX and other commercially valuable components, such as LAr from liquefied air, which consists primarily of LN2. Strong magnetic field gradient and gravity are used to separate LOX from liquefied air, based upon the different magnetic properties of LOX and LN2. The apparatus and method employ a magnetic field gradient to levitate the LN2 and LAr diamagnetic components of liquid air while accelerating the paramagnetic LOX component toward the bottom to achieve oxygen separation. In other embodiments, a leak valve system can be used.