Silica products from geothermal fluids by reverse osmosis
US11198095B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 2015 |
| Grant date | Dec 14, 2021 |
| Priority date | — |
| Expiry date | Sep 2, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2103/06
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The invention concerns a method and apparatus for producing silica concentrates from geothermal fluids containing at least 300 ppm silica, by passing the fluid at a temperature above 80° C. and at a pH reduced to between 4.0 and 7.5 through a reverse osmosis membrane. In the diagram, geothermal fluid (I) is passed to a separator (2) to be flashed to produce steam (3) and separated geothermal water (SGW) (4). The SGW (4) is passed to a heat exchanger (5) then inlet pump (7). Acid is introduced to the geothermal fluid flow at a dosing means (6) to reduce the pH and an anti-sealant may also be introduced. The geothermal fluid is then passed to a reverse osmosis unit (8) to produce a concentrate (9) and a permeate (10). Following reverse osmosis, the concentrate and permeate may be treated with other processes to produce the desired product and concentration. For example, if precipitated silica is produced, the concentrate is passed to a curing tank (11) and to a thickener (12). The precipitated silica is collected (13) while the retained fluid is removed (14).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.