The October edition of Manufacturing Engineering presents this nice article discussing issues related to increasing the life of the coolant.  Several systems are discussed, including: Prab Guardian coolant recycling systems, the Eriez Sump Doc, the JK Industries HydroClean coolant filtration system, Jorgensen Conveyers UVS Ecologic (conveyers), and John Hart USA (chip briquetting system).  Manufacturing Engineering is an SME publication.  Visit sme.org.