A system is described for producing small uniform pellets of predetermined size which are substantially free of fines from mechanically dewatered sewage sludge. The system includes a process and apparatus for mixing the dewatered sludge with previously dried, recycled particles of said sludge, drying...http://www.google.com.au/patents/US4956926?utm_source=gb-gplus-sharePatent US4956926 - Sludge treatment process
