The objective of the research reported was to determine the technical feasibility of using air classification to process or treat selected types of nonhomogeneous, dry solid wastes. Design requirements for processing solid wastes with a full-scale commercial unit are estimated and the required supplemental equipment (shredders, screens, dryers) are identified. Limitations and advantages of the method are listed. The air classification method was shown to be applicable to salvage of paper, recovery of nonferrous metal from shredded automobile body waste, and processing of compost. This method was shown to be technically feasible for processing wastepaper. It was also concluded that air classification is technically feasible for processing semifibrous solid waste materials such as compost. Compost can be cleaned of glass and other contaminants that reduce its marketability.