Patent ID: 8734751

Claim:
A method for recycling and treating wastes of silicon wafer cutting and polishing processes, the method comprising: step (A): putting a filter cake which is dewatered in advance into a treatment tank, wherein the filter cake is formed by filter-pressing a waste oil slurry generated from the silicon wafer cutting and polishing processes and at least contains silicon (Si) particles, silicon carbide (SiC), and a residual cutting fluid composed mainly of polyethylene glycol (PEG); step (B): adding a reactant into the treatment tank so that the filter cake is mixed with and diluted by the reactant to form a working fluid, in which the silicon particles and the reactant undergo a catalyst reaction to generate solid silicon dioxide (SiO 2 ) and gaseous hydrogen (H 2 ); step (C): drawing the hydrogen from within the treatment tank to a gas storage tank for pressurized storage; step (D): separating, by specific gravity separation, remaining said silicon particles and the silicon carbide from the working fluid, which has a diluted slurry concentration, so as for the remaining silicon particles and the silicon carbide thus separated to be sorted and recycled; step (E): performing solid-liquid separation, by way of membrane filtering, on the working fluid from which the remaining silicon particles and the silicon carbide have been separated, thereby separating the working fluid into the solid silicon dioxide and a liquid of water and PEG; and step (F): applying a reverse osmosis (RO) treatment to the liquid of water and PEG, so as to obtain reusable water and a reclaimed cutting fluid composed mainly of PEG.