Process for reducing sludge accumulation in the hot water extraction process for oil sands
US5492628A · kind A · utility
Assignees
- Alterra Energy, LLC
- Canadian Occidental Petroleum Ltd.
- Esso Resources Canada Limited
- Gulf Canada Resources Limited
- Her Majesty the Queen in right of the Province of Alberta, as represented by the Minister of Energy and Natural Resources
- HBOG-Oil Sands Limited
- Pan Canadian Petroleum Limited
- PETRO-CANADA
- Mocal Energy Limited
- Murphy Oil Company Ltd.
Inventor
Key dates
| Filing date | Oct 6, 1994 |
| Grant date | Feb 20, 1996 |
| Priority date | — |
| Expiry date | Oct 6, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10G1/047
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A dispersant, such as sodium silicate, is added to the process water of the hot water extraction process which recovers bitumen from oil sands. The dispersant disperses the ultrafine (less than 300 nm) particles, to reduce the formation of flocs and sludge in the tailings pond. The volume of the pond is such that the retention time of process water is sufficiently short (less than 6 weeks when using sodium silicate) to avoid reforming flocs from the dispersed ultrafines. The ultrafines content in the process water builds up as the water is repeatedly recycled from the pond to the extraction process. The ultrafines content stabilizes at a steady state concentration as some ultrafines are continuously removed from the process water when the tailings are delivered onto the "beach" of the pond and become trapped in the sand.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.