The spent bleaching earth cake is flushed by steam or nitrogen to recover as much of the entrained oil from the cake as possible. Bleaching is usually
performed in one single step, but in order to reduce the consumption, alternative multi-step bleaching processes have been developed; most known are the two-stage co-current and counter-current bleaching processes. The co-current process is the least complicated. Bleaching earth is added in two consecutive stages in the oil, with a filtration after every stage.