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U.S. Department of Energy
Office of Scientific and Technical Information

Process for stabilizing silica-rich geothermal brine to prevent silica scaling

Patent ·
OSTI ID:5458828

A process for stabilizing silica-rich geothermal brine to prevent silica scaling comprises selectively providing a supply of ferric ions, allowing the silica-rich brine to combine with the ferric ions to form insoluble, iron-rich siliceous material and separating the insoluble siliceous material from the brine to form a brine having a silica content which is reduced below the saturation level required for substantially scale-free handling of the brine. In one embodiment of the process in which the brine contains sufficient dissolved ferrous ions, the process comprises selectively contacting the brine with an oxidizing agent, preferably by aerating the brine, to oxidize a selected portion of the ferrous ions to ferric ions, which then combine with silica to form the insoluble iron-rich siliceous material. The ferric ion content of an iron-deficient brine may be augmented by adding ferric and/or ferrous ions to the brine. Steam released by flashing the untreated brine may be used to heat the stabilized brine beford disposal thereof, so as to increase the silica solubility and reduce the amount of silica required to be removed to prevent scaling.

Assignee:
Union Oil Company of California
Patent Number(s):
US 4405463
OSTI ID:
5458828
Country of Publication:
United States
Language:
English