The influence of Sahara sand on the degradation behavior of float glass surfaces

The study shows that the adhering sand drastically enhances the leaching of the network modifiers Na and Ca and furthermore adsorbs them. It also effects crystallization processes: For sand-free weathered glasses the formation of dendritic trona and massive sodium bicarbonate layers could be verified within this study. While sand-weathering the formation of carbonates is suppressed due to the adsorption of network modifiers by the sand and the formation of aluminosilicates on the glass surface is observed. These aluminosilicates would lead in ongoing weathering to more drastic corrosion damages than carbonates due to their high alkalinity. Hence, sand is not an inert material only lowering the light transmittance of glasses when covering them. It actively changes the properties of glass surfaces and fastens their degradation.