Fig. 1. (a) Chemical composition of the supernatant solution for STW1 (0.1 M NaOH) and STW2 (0.5 M NaOH) reactions as a function of time, and (b) acidic ammonium oxalate extractable Al, Si, and Mg from colloidal reaction products. 14-pNCA is noncarbonate alkalinity at the same scale as pH.