| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method and means for disposing and recovering waste cutting liquid, which enables silicon and silicon carbide to be recovered by a simple operating procedure and means. <P>SOLUTION: The method includes: a first step of stirring a mixing the cutting liquid with dilute hydrochloric acid to produce a fluid mixture; a second step of overheating the mixture for liquid separation so as to evaporate water and polyethylene glycol, and cooling and dehydrating the evaporated water and polyethylene glycol to recover polyethylene glycol which is to be subjected to liquid separation so as to obtain a solid mixture of silicon carbide and silicon; a third step of secondarily cleaning the solid mixture so as to recover a secondarily cleaned solid mixture of silicon carbide and silicon; and a fourth step of recovering silicon carbide and silicon with a mixed acid solution composed of nitric acid and hafnium to recover the silicon carbide and silicon. A recovery rate is 26 to 46% according to calculation based on the weight of the waste liquid. <P>COPYRIGHT: (C)2012,JPO&INPIT |
