玻璃可否循環再用

Yes, glass is one of the few materials that recycle very well.
They can be broken, mixed, contaminated with other things, and can still be recycled.
When manufacturing, they usually have a mountain of recycled glass chips from which they add to the new glass products. The high temperature of the production will melt together old and new to make 'brand-new' glass.
The only thing to watch is the colour. However, any colour is good for beer bottles or the like.