Iron silicate scale formation and inhibition at the salton sea geothermal field

Iron silicate is the most prevalent scale deposited from Salton Sea geothermal brine during processing to recover its heat content. The scale has been characterized by elemental analysis and by infrared, nuclear magnetic resonance, Mossbauer and electron diffraction spectroscopy. Analysis of the scale characterization data assists in assigning a chemical structure and supports a proposed formation mechanism. Based on this mechanism, iron silicate scale deposition is shown to be inhibited by the addition of acid to the brine, forming the basis of Unocal's patented scale control technology.