METHOD FOR SEPARATING CHLORINE-CONTAINING PLASTIC FROM WASTE PLASTIC BY CENTRIFUGAL SPECIFIC GRAVITY SEPARATION APPARATUS

摘要

PROBLEM TO BE SOLVED: To prevent the lowering of separation efficiency by preventing the internal clogging of a centrifugal specific gravity separation apparatus when chlorine-containing plastic is separated from waste plastics by the apparatus. SOLUTION: Waste plastics 10 are charged in a washing and mixing tank 2 by a conveyor 1 and washed with water (specific gravity liquid) while stirred and mixed by a stirrer 3. A slurry consisting of waste plastics and water is supplied to a centrifugal specific gravity separation apparatus main body 5 by a slurry supply pump 4 to be separated into a light material 7 useful for reutilization and a heavy material 7 containing chlorine-containing plastics corresponding to specific gravity difference with respect to water. In supplying the slurry to the centrifugal specific gravity separation apparatus main body 5, the flow rate of the supplied slurry is measured by a slurry flowmeter 8 and the speed of the charging conveyor 1 is controlled corresponding to the measured value. By this constitution, the amt. of waste plastic supplied to the centrifugal specific gravity separation apparatus main body 5 is adjusted to a predetermined value.