Inhibition of Dissolution Passivity

It is important to understand the factors that retard dissolution. The same question is especially relevant in technical systems, and in the corrosion of metals and building materials. Passivity is imparted to many metals by overlying oxides the inhibition of the dissolution of these passive layers protects the underlying material. 

Lake Cristallina - Weathering reactions 1 timol calcite -2 2  

4) Loss of H4Si04 due to incorporation in diatoms and adsorption on noncrystalline AI(OH)3 not included 

5) From greatest to least these reactions could also be written, instead of with H+ ions as reactants, with water and dissolved C02. In either scheme, the net result of the reaction is the same - cations (Ca2+, Mg2+, Na+, K+ are released, and alkalinity is produced via OH or HCO 3 production or H+ consumption. In all reactions, the equivalents of cations released are exactly balanced by the equilvalents of add consumed which corresponds to the alkalinity produced. 

As shown by Grandstaff (1976) the cations, thorium, lead and the rare earths, associated with uraninite retard the dissolution of UO2 significantly. 

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