Glass recycling

How do they remove contaminates like dirt and dried juice from glass during the recycling process? And how do they get rid of the paper/plastic labels? At what point in the process does that take place?

Thought of another question

Why can’t Pyrex and window glass be recycled?

Recycled glass is remelted at about 1500 degrees. Any contaminants and labels do not survive that kind of heat.

Pyrex is a very different glass, and melts at a much higher temperature.
Window glass can be recycled, but is very dangerous for the people sorting the waste stream, so it is forbidden.

I have heard window glass can be old enough to contain lead, therefore is excluded.

Some inorganic contaminants may float to the top, sink, or be dissolved into the glass. Iron is a big problem catalyzing the degradation of the furnace liner.

Window glass usually has a low emissivity (Low E) coating on the surface that is a thin layer of various metal oxides.

That’s why it doesn’t get recycled.

Those coating are relatively new and I am not sure how wide spread.