| 摘要 |
<p>A method of preparing bisphenol A of high purity, in which a degree of concentration of slurry product of bisphenol having phenol added thereto in the crystallization tank is estimated on-line with the computer on the basis of material balance and heat balance in said tank so that said bisphenol having phenol added thereto is crystallized while keeping said concentration degree of slurry at a fixed level. According to this invention, slurry kept within a fixed range of concentration can be fed to slurry separation process all the time, whereby stable operation in the slurry separation process is ensured to help improve productivity. Hence, adhesion of an excessive quantity of filtered liquid containing impurities of crystals of bisphenol A can be prevented and bisphenol A of high purity is obtained.</p> |
