Controlled silica precipitation in geothermal brine at the Reykjanes geo-chemicals plant

Journal Article · Sun Jan 01 00:00:00 EST 1989 · Geothermics; (USA)

DOI:https://doi.org/10.1016/0375-6505(89)90016-3· OSTI ID:5323015

Gudmundsson, S R ^[1]; Einarsson, E ^[2]

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1. Virkir, Sidumula 1, 108 Reykjavik (IE)
2. Reykjanes Geo-Chemicals Ltd., Reykjanes (IE)

This article describes how silica was precipitated in an electromagnetic field from silica supersaturated brine. At the Reykanes Geo-Chemicals plant deposition of silica was a serious problem. After acidification of brine to pH 2.5 before evaporation the silica can be kept in solution for a considerable time. In order to precipitate silica out of this brine caustic soda is added. To get an effective precipitation of silica, a pH of at least 8.2 has to be reached. By using an electromagnetic field, a pH of 7.3-7.8 is sufficient to precipitate silica and an increased settling rate is observed. Settling rates were found to be from 7.1-9.7 cm/min at 100{sup 0}C and from 3.4-4.6 cm/min at 40{sup 0}C, compared to 1.3 cm/min for silica which was only alkalized. Higher effluent purity is also achieved by using electromagnetic field to precipitate out silica.

• OSTI ID: 5323015
• Journal Information: Geothermics; (USA), Vol. 18:1; ISSN 0375-6505
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
BRINES
ACIDIFICATION
GEOTHERMAL FLUIDS
SCALE CONTROL
ELECTROMAGNETIC FIELDS
GEOCHEMISTRY
GEOTHERMAL SYSTEMS
PH VALUE
SILICA
CHALCOGENIDES
CHEMISTRY
CONTROL
FLUIDS
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
SILICON COMPOUNDS
SILICON OXIDES
150903* - Geothermal Engineering- Corrosion
Scaling & Materials Development