Method for obtaining large crystals with high purity by destructing part of fines in slurry in a crystallizer
US5663456A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Dec 26, 1995 |
| Grant date | Sep 2, 1997 |
| Priority date | — |
| Expiry date | Dec 26, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C37/685
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention provides a method, which can be operated continuously and has a wide scope of application, for destructing part of fines in slurry in a crystallizer to obtain large crystals having high purity and large crystal size, characterized in that first and second filters are installed in the crystallizer, a part of slurry containing only fines of size smaller than the fines cut size is drawn from the crystallizer, through the first filter in the crystallizer to a fines destruction loop for destructing the fines and then to the crystallizer through the second filter in the crystallizer by using a circulating pump. The two filters are switched over at regular interval and washed with each other's effluent to ensure the cintinuous operation of the above process. The present invention also provides a method for preparing crystalline bisphenol A/phenol adduct and bisphenol A with high purity and large crystal size.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.