In-situ study of the kinetics of phosphoric acid interaction with calcite and fluorapatite by Raman spectroscopy and flotation

In the reverse anionic flotation of phosphate ores using phosphoric acid, it is often suggested that a selective surface passivation minerals by calcium occurs. Several species have been proposed in literature for this passivation. study, in-situ Raman spectroscopy was used to monitor as function time interaction acid with calcite and fluorapatite at fixed pH 4.5 or concentrations order identify what formed conditions similar those flotation. X-ray photoelectron also confirm more clearly surface. Although (1:1) observed on both minerals, its presence highly dependent concentration latter controls dissolution precipitation. The results mineral confirmed importance solution, originating from addition and/or dissolution, formation/precipitation which can turn off fluorapatite, both.