Preston, J.S., Cole, P.M., Craig, W.M. and Feather, A.M. (1996) The Recovery of Rare Earth Oxides from a Phosphoric Acid By-Product. Part 1 Leaching of Rare Earth Values and Recovery of a Mixed Rare Earth Oxide by Solvent Extraction. Hydrometallurgy, 41, 1-19.
https://doi.org/10.1016/0304-386X(95)00051-H

has been cited by the following article:

• TITLE: Phosphogypsum Processing for Rare Earths Recovery—A Review

  AUTHORS: Xiaosheng Yang, Dandara Salvador, Hannu Tapani Makkonen, Lassi Pakkanen

  KEYWORDS: Phosphogypsum, Rare Earth Elements, Phases of Rare Earth Elements, Acid Leaching

  JOURNAL NAME: Natural Resources, Vol.10 No.9, September 11, 2019

  ABSTRACT: As a by-product from the phosphate fertilizer industry Phosphogypsum (PG) was considered a potentially valuable source of the rare earth elements (REEs). Because of trace concentration of REEs in the PG (normally 2SO4, HCl and HNO3, and organic chemicals, the effects of mechanical treatment of PG by microwaving and grinding on leaching efficiency of REEs, and resin-in-leach process were reviewed in the paper.