RECOVERY TREATMENT METHOD OF WASTE LIQUID OF SILICON CUTTING SLURRY

摘要

PROBLEM TO BE SOLVED: To provide a method for efficiently recover a coolant and abrasive grains from slurry waste liquid discharged in a silicon wafer cutting process using a wire saw.;SOLUTION: In a recovery treatment method of waste liquid of silicon cutting slurry, the system is equipped with a raw material tank 3 storing waste slurry, an extraction tank 5 which extracts coolant by mixing waste slurry and supercritical carbon dioxide fluid, a gas liquid separation tank 6 which separates the coolant and carbon dioxide gas by depressurizing the supercritical fluid, and a compression heater 4 for maintaining the carbon dioxide to be recovered in a supercritical state. The coolant other than solid content can be extracted from the slurry waste liquid as it is without using organic solvent, alkalis, and acid, and residual as a solid content can be extremely reduced.;COPYRIGHT: (C)2007,JPO&INPIT