Abstract
Electrochemical techniques were used to measure the equilibrium constants of lead(II) organic complexes up to 90°C. The data are extrapolated to 200°C. The equilibrium speciation model EQBRM was used to calculate the significance of organic complexing in Na-Ca-Cl-bearing brines, from 50° to 200°C, by comparing total organic complexing to total chloro complexing with lead(II) and zinc(II). The significance of organic complexing in hydrothermal brines depends mostly on the solubility of the calcium(II) organic salts, the concentration of calcium in solution, the thermal stability of the organic species, and the acidity of the ligands' binding groups. The model showed that acetate (or other soluble carboxylates) complexes with lead(II) and zinc(II) can predominate over chloro complexes under neutral to slightly acidic pH conditions when present at concentrations which have been observed in hydrothermal brines. -from Authors
Original language | English (US) |
---|---|
Pages (from-to) | 742-764 |
Number of pages | 23 |
Journal | Economic Geology |
Volume | 83 |
Issue number | 4 |
DOIs | |
State | Published - 1988 |
All Science Journal Classification (ASJC) codes
- Geophysics
- Geology
- Geochemistry and Petrology
- Economic Geology