approximately half of the waste passes first through a drum to segregate the fine fractions and then is conveyed on two treadmills this permits the waste pickers to collect recyclable waste plastics glass metals the waste contains no paper or carton which has already been picked up before the waste is collected and sold to a wholesaler industry is increasingly interested in the possibility of coincinerating its waste in cement plants the combustion systems at many cement plants have been readapted to allow the coincineration of several types of waste this involves mainly waste containing polychlorinated biphenyls pcbs tons in