Experiences with selective extraction procedures for iron oxides

摘要

Four extraction procedures - acid ammonium oxalate, hydroxylamine hydrochloride, Tiron and dithionite-citrate - designed to extract ferrihydrite and specific crystalline iron oxides, were assessed for relatively unweathered, sensitive, post-glacial marine clays and for intensively altered, argillaceous material surrounding a uranium deposit. The procedures were more aggressive in extracting oxides other than the target oxide, as well as Fe-bearing and non-Fe-bearing aluminosilicates, than the literature suggests. Reassessment of geochemical investigations where these and other extraction procedures have been used may be needed.