Fig. 3From: Alkali treatment–acid leaching of rare earth elements from phosphogypsum fertilizer: insight for additional resource of valuable componentsConcentrations of different REEs, ppm in PGF, and that leached from one-cycle with 1.0 mol/L citric acid solution, at agitation time 15.0 min, L:S = 5:1 and 85 °C.Back to article page