Fig. 6

a Leaching studies at 298 K for 60 min b Leaching studies at 298 K for 120 min c Leaching studies at 298 K for 180 min using 1 mol/L acid.

a Leaching studies at 298 K for 60 min b Leaching studies at 298 K for 120 min c Leaching studies at 298 K for 180 min using 1 mol/L acid.