Abstract: A method and apparatus for centrifugal solids separation for use in the drilling industry, concerned with the conservation of drilling mud. The apparatus comprises a rotatable container, a device for inputting used mud to the container preferably with minimal turbulence, a collection device for collecting and compacting separated solids material, a device for wiping separated solids material from the sides of the container and preferably directing this material to the collection a device and an output from the container for cleaned mud. So that the apparatus may be employed for continuous mud cleaning or solids separation, the collection device may be isolated from the container to allow dumping of collected solids material. Where there are multiple collection compartments there may be a synchronised cycle of dumping of the collection device to maintain balance of the container during continuing centrifugal rotation.