Chemical behaviour of geothermal silica after precipitation from geothermal fluids with inorganic flocculating agents at the Hawaii Geothermal Project Well-A (HGP-A)

Basic Information
Author: De Carlo, EH
Description:The report summarizes the results of experiments dealing with the problem of removal of waste-silica from spent fluids at the experimental power generating facility in the Puna District of the island of Hawaii. Geothermal discharges from HGP-A represent a mixture of meteoric and seawaters which has reacted at depth with basalts from the Kilauea East Rift Zone under high pressure and temperature. After separation of the steam phase of the geothermal fluid from the liquid phase and a final flashing stage to 100 degrees Celsius and atmospheric pressure, the concentration of the silica increases to approximately 1100 mg/L. This concentration represents five to six times the solubility of amorphous silica in this temperature range. We have evaluated and successfully developed bench scale techniques utilizing adsorptive bubble flotation for the removal of colloidal silica from the spent brine discharge in the temperature range of 60 to 90 degrees C. The methods employed resulted in recovery of up to 90% of the silica present above its amorphous solubility in the experimental temperature range studied.
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Author Contact Information
Distributor Contact Information
Name: Beth Tillinghast
Organization Name: Missing
Street: Hamilton Library
City: Honolulu
State: HI
Zip: 96822
Phone: (808) 956-6130
Geographic Extent
North Bounding Latitude: 23.0030323058
South Bounding Latitude: 18.5255898237
East Bounding Longitude: -154.523261585
West Bounding Longitude: -160.895331897