Physicochemical model of tin behavior in weathering profiles

Resumo

Numerical simulations of a weathering profile on granite containing 10^–8 mol/L Sn (whose average content in the Earth’s crust is 0.00025%) by the SELECTOR program package indicate that cassiterite SnO₂ solubility under both oxidizing and reducing conditions is no higher than 10^–10 mol/L within the pH range of 3 to 11. The only ion occurring in equilibrium with cassiterite is the neutral Sn(OH)_4(aq)⁰ complex, which was detected in both oxidizing and reducing environments.