Premium
The Dissolution of Complex Ferric Phosphates Under Controlled E h and pH Conditions
Author(s) -
Williams B. G.,
Patrick W. H.
Publication year - 1973
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1973.03615995003700010015x
Subject(s) - dissolution , ferric , chemistry , solubility , phosphate , potassium , calcium , inorganic chemistry , phosphorus , nuclear chemistry , organic chemistry
The dissolution of complex ferric phosphates, CaFe 2 H 4 (PO 4 ) 4 · 8H 2 O and KFe 3 H 14 (PO 4 ) 8 · 4H 2 O, was studied in a reduced chemical system. Both salts dissolved incongruently to release calcium and phosphorus in a molar ratio of 1:2 and solid FePO 4 . Below an E h of — 200 mV further P was released due to FePO 4 dissolution. Potassium ferric phosphate crystals dissolved rapidly with complete release of K, whereas dissolution of calcium ferric phosphate was retarded probably due to interference by precipitated FePO 4 . The solubility of precipitated FePO 4 differed slightly from that observed with crystalline strengite and at pH 6 and 7, ferric hydroxides apparently entered into the reaction.