Radioactive waste water treatment
US4800042A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 1987 |
| Grant date | Jan 24, 1989 |
| Priority date | — |
| Expiry date | Jan 27, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S159/12
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A volume-reducing solidification treatment method for radioactive waste liquid containing boron primarily in the form of boric acid or borates is disclosed. After an alkali is added to the waste water to adjust pH thereof, and optionally after evaporation concentration is carried out, soluble calcium compounds such as Ca(OH).sub.2 are added, the waste water is stirred at a specific temperature to form insoluble calcium borate aged at a lower temperature than that of forming borate, and evaporation and concentration is carried out, which raises the concentration of the solid component. The concentrated liquid obtained is solidified with cement. The concentrated liquid may also be dried into a powder using a thin film evaporator. Liquid containing insoluble calcium borate obtained after solid-liquid separation may be recycled for use as a waste water pH adjusting agent, or, may be evaporated and concentrated, and the concentrated liquid may be solidified with cement along with the concentrated solid component obtained through solid-liquid separation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.