pipe 18 and the casing 20w in response to the inrush of dirty mud via pipe 14 interiorly rotating 34 heavy 34 materials will be centrifugally forced into annular void 19 and out through pipe 22 while 34 lighter 34 materials will be drawn out through pipe 18 materials outputted through pipes 18 and 22 must be further processed however a large generally cylindrical material processing drum broadly designated by the reference numeral 30 is elevated in the center of the apparatus and supported upon the desilter inlet channel 18 which extends coaxially rearwardly out of the initial cyclone chamber 20 fig2 further support is provided for the central drum by the rigid desander pipe 22 fig4 which extends vertically out of the cyclone chamber 20 through the lower floor 30f of drum 30 the rigid angular mount 31 fig2 and 3 includes a rigid generally triangular preferably steel plate 32 which is suitably bored to receive a crane hook or the like is permanently connected to the outer sides of the central drum 30 by means of welding or the like to permit convenient transport and placement of the apparatus 10 at the selected drilling site as best illustrated in fig5 9 the generally hollow interior of the drum 30 comprises an upper level desilting chamber 31e and a lower level 31x which are separated from one another by a rigid interior floor 31g chamber 31e is a collection chamber for desilted mud and the desilting cones discharge into it lhe lower level 31k is divided into a desilter feeding chamber 30b and an adjoining desander feeding chamber 30a fig6 which is divided.