I wonder if I can use for fixing other tubes instead of the patches...
I don't see why not. Probably best to use the outer side to stick to the tube you're patching, not the inside, which will have a powdered surface, and the glue wouldn't stick properly. Probably best to cut the tube open into a long strip and wash it well to de-grease and de-powder it.
As everyone has said, I use them to make other stuff out of, but they have a million other uses, like shims, rubber bands, tree-ties, bungees.
However, ultimately, no, they probably won't be recyclable in your household recycling box. There are companies that recycle car tyres, chipping them to made a soft surface for riding schools, but they usually don't deal in bike stuff, too small. If you're really keen, check with your local authority though, as rules vary hugely across the country.
I trust you're not throwing them out until well patched? At work, our load trikes don't get new tubes until the old ones have a dozen patches on...
