INVESTIGATION OF THE DISSOLUTION OF METALLIC SILICON SPHERES IN A CONTAINER GLASS MELT

On laboratory scale, metallic silicon spheres obtained from industrial flint glass production and spectroscopically pure silicon were anneal ed in flint glass, amber glass and green glass cullet melts. The disso lution behavior of silicon was investigated in the temperature range o f 1200 to 1500 degrees C in normal air and sulfur dioxide atmosphere. Silicon dissolves by formation of a thin silicon dioxide layer at the surface of the spheres only at high temperatures and long annealing ti mes. The dissolution of silicon is a process with low reaction rate an d a complex reaction mechanism due to interactions of silicon with oxy gen, hydroxide ions and polyvalent ions in the container glass melt.