Synthesis of Analcime Crystals and Simultaneous Potassium Extraction from Natrolite Syenite

Figure 4

SEM images of samples prepared at different NaOH concentrations: (a) 0.0 mol/L, (b) 0.5 mol/L, (c) 1.0 mol/L, and (d) 1.5 mol/L.

(a)

(b)

(c)

(d)