Ferrous sulfide-containing passivator for removing heavy metal from soil and preparation method and use thereof
US12083491B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Aug 19, 2022 |
| Grant date | Sep 10, 2024 |
| Priority date | — |
| Expiry date | Mar 11, 2043 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB09C2101/00
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for preparing the ferrous sulfide-containing passivator includes: dissolving a sulfide in an alkaline solution to form a mixed solution with a pH of 12-13; adding sodium silicate to the mixed solution and stirring for 0.5-1 hour at 20-40° C.; adding an aqueous solution of ferrous salt to the mixed solution containing sodium silicate, and allowing to react at 40-60° C. for 2-3 hours; where, with decrease of the pH of the mixed solution, sodium silicate is converted into silica nanoparticles, and the ferrous salt reacts with the sulfide to form ferrous sulfide; and further adding an aqueous solution of an organic modifier, and allowing to react at 40-60° C. for 1-2 hours to form a passivator slurry including surface-modified ferrous sulfide doped with silicon dioxide; filtering the passivator slurry to form a passivator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.