Quartz Sand Treatment

Solubility in H2O (%)

Extractable Si (%)

Untreated (origin)

0

HCl-washed and boiled (A)

0

0.0060 - 0.0073 (0.0067 ± 0.0007)

A + NaOH (s)-mixed and heated

79.5

11.7670 - 12.2000 (11.9835 ± 0.2165)