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Table 3 Reactions used to model the precipitation of low temperature iron and silica oxyhydroxides in the system Fe–Si–O–H shown in Fig. 7

From: Microbial and hydrothermal aspects of ferric oxyhydroxides and ferrosic hydroxides: the example of Franklin Seamount, Western Woodlark Basin, Papua New Guinea

Fe (OH)3 (fresh ferric hydroxide) (s) + 2H+ =
Fe2+ + 5/2 H2O + 1/4O2
Fe3(OH)8 (fresh ferrosic hydroxide) + 6H+ =
3Fe2+ + 7H2O + 1/2O2
3Fe(OH)3 (fresh ferric hydroxide) =
Fe3(OH)8 (fresh ferrosic hydroxide) + 1/2H2O + 1/4O2
Fe3(OH)8 (fresh ferrosic hydroxide) =
3Fe(OH)2 (fresh ferrous hydroxide) + H2O + 1/2O2
Fe(OH)2 (fresh ferrous hydroxide) + 2H+ = Fe2+ + 2H2O
SiO2 (amorphous) + 2H2O = Si(OH)4
FeSiO3 (ferrosilite) + 3H2O = Fe(OH)2 (fresh ferrous hydroxide) +
Si (OH)4
FeSiO3 (ferrosilite) + 10H2O + 1/2O2 =
Fe3(OH)8 (fresh ferrosic hydroxide) + 3Si(OH)4
FeSiO3 (ferrosilite) + H2O + 2H+ = Fe2+ + Si(OH)4