| Title | Precious Metals in the Salton Sea Geothermal Brines |
|---|---|
| Authors | McKibben, Michael A.; Williams, Alan E.; Hall, Gwendy E. M. |
| Year | 1989 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Brine Technology; USA; California; Imperial; Salton Sea; Chemistry; Brine; Analytical Methods; Sampling; Sealing; Gold; Transport; PGE; Precipitation |
| Abstract | Production fluids, reservoir rock veins, well head pipe scales and downhole liner scales from the Salton Sea geothermal system have been analyzed for Au and Platinum group elements (PGE). Au and PGE levels in sampled production fluids are <0.3 ppb. Veins from reservoir rocks contain <5 ppb Au or PGE. IN scales, PGE concentrations are <13 ppb, but Au concentrations range from 0.1 to > 1000 ppm. The highest Au concentrations occur in downhole liner scales. Thermodynamic calculations indicated that the reservoir brines should be transporting 0.2 ppb Au, in excellent agreement with the measured values in production fluids Mass balance calculations suggest that, although the Au contents are relatively high in the scales, they represent scavenging of only 2% of the total Au that passes through the wellbore. A typical well produces 240 g (7.7 troy oz) of Au in one year, PGE transport appear to be legible. |