Recovery/removal of metallic elements from waste water using ozone
US6485696B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1999 |
| Grant date | Nov 26, 2002 |
| Priority date | — |
| Expiry date | Oct 29, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Ozone is used to rapidly oxidize specific metallic elements. The insoluble oxidized compounds of the metals formed by the ozonation are then recovered for industrial use in a conventional sedimentation/filtration tank or pool. There is no requirement for pre-treating or neutralizing the acid mine discharge, even when iron is the dominant metal. If the pH of the untreated acid mine discharge is less than about 2.5, metals other than iron precipitated first. After that, the pH is raised and the iron is precipitated as ferric hydroxide. Aluminum is removed as hydrated aluminum compounds after removal of the iron prior to discharging the acid mine discharge to streams. Both the ozonation and neutralization processes are monitored and controlled using electrochemical sensors and feedback controllers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.