Method for producing chemically bonded phosphate ceramics and for stabilizing contaminants encapsulated therein utilizing reducing agents
US6133498A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 5, 1999 |
| Grant date | Oct 17, 2000 |
| Priority date | — |
| Expiry date | May 5, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/91
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Known phosphate ceramic formulations are improved and the ability to produce iron-based phosphate ceramic systems is enabled by the addition of an oxidizing or reducing step during the acid-base reactions that form the phosphate ceramic products. The additives allow control of the rate of the acid-base reactions and concomitant heat generation. In an alternate embodiment, waste containing metal anions are stabilized in phosphate ceramic products by the addition of a reducing agent to the phosphate ceramic mixture. The reduced metal ions are more stable and/or reactive with the phosphate ions, resulting in the formation of insoluble metal species within the phosphate ceramic matrix, such that the resulting chemically bonded phosphate ceramic product has greater leach resistance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.