LAUSR

The binding of Na+, K+, and Li+ by magnesium silicate hydrate (M–S–H) was investigated in batch sorption experiments. Sorption isotherms and cation exchange measurements indicated the binding of alkalis in cation exchange sites compensating the negative surface charge of M–S–H. Higher pH values led to further deprotonation of the silanol groups and a higher alkali uptake by M–S–H. No significant incorporation of alkalis in the main silica or magnesium oxide sheets was observed. However, the silica sheets were less polymerized in the presence of higher alkali hydroxide concentrations.