FLOTATION OF MOLYBDATE OXYANIONS IN DILUTE-SOLUTIONS .1. SELECTIVE SEPARATION FROM ARSENATE

Ion flotation using a common cationic surfactant (dodecylamine) as col lector was used for the quantitative recovery of molybdenum from dilut e aqueous solutions. When arsenic co-existed with molybdenum in the so lution, both arsenic and molybdenum were recovered. In this case, adso rbing colloid flotation, using ferric hydroxide as co-precipitant (or sorbent) and also dodecylamine as collector, has been examined for the selective separation of arsenate from molybdate anions. It was found that over 98% of arsenic could be separated from the molybdate solutio n at pH 9, while the loss of molybdenum in the foam (in one stage) was less than 10%. The flotation mechanism by dodecylamine is discussed a nd also compared with that of sodium dodecyl-sulphate, a common anioni c surfactant.