Use of eriochrome cyanine R for separation-flotation and microdetermination of hafnium and zirconium in real samples

Eriochrome cyanine R (ECR) is investigated as a collector for separation an d flotation of hafnium from zirconium through the use of an oleic acid surf actant. Selective separation of Zr(IV) is achieved at pH 2 with maximum eff iciency, whereas Hf(IV) is completely separated at pH 7.0-7.5. Excess ECR i s used to avoid interferences from foreign ions without any effect on the s eparation efficiency. The procedure is successfully applied to the determin ation of Zr(IV) and Hf(IV) in real samples. A flotation mechanism is propos ed.