Purification of Kroll's Reduction Unreacted Hafnium Oxide Residue: Purification of Kroll's Reduction Unreacted Hafnium Oxide Residue: Rayapudi, Reddy, and Shaik. - Rayapudi, Veeranjaneyulu; Reddy, Raghu C.; Shaik, Mowlali (JOM: The Journal of The Minerals, Metals & Materials Society (TMS), 2025)