A filter assembly for a dryer appliance is provided. The filter assembly includes a filter medium rotatably mounted within a filter cassette that is removably received within a filter slot of the dryer appliance. The filter medium has a first portion and a second portion that are selectively exposed to a stream of exhaust air from the dryer appliance to extract lint. While one portion is filtering lint, a lint removal system removes the lint from the other portion collected during the prior cycle. After each cycle, a motor is configured for rotating the filter medium to expose the clean portion of the filter. The filter cassette is removably received within the filter slot using a magnetic latching mechanism, a securing cover, or another suitable mechanism. A scrubber mechanism may also be used to remove stubborn lint.