Which method of separation do you use to separate sawdust and sugar?

Add water, stir til sugar dissolves, fiter repeatedly until the water is clean, slow evap to retrieve the sugar. Add the dust and sand from the filter (most will have separated pretty well, sand on bottom etc) into a cup/beaker/bucket etc and fill with water, put it in a deep tray and add water very slowly to the bucket until the sawdust has all spilt over the edge. Your sand will be in the bucket and sawdust will have overflowed into the tray.