New glass contains about 30% old glass, called ‘cullet’. It is cheaper to melt glass than produce it from raw materials. The chemicals that give glass color are expensive so the old glass is valued. There has always been glass available for remelting, even before the recycling crazy began n the 60’s.
Oh, washing bottles to be recycled is a waste of water. Glass melts at 2,700 F., incinerating any organic material. Metal should be removed as it causes the silica to turn to silicon beads which weaken the bottle.
Glass furnaces run 24/7/365 from the time they are fired-up untl they are torn down years later when the fire-brick that lines them gets too thin.
I still live in a small city that was a major glass producer in the 1900’s. As a child, we used to play in the alleyways and dig up pieces of colored glass that was mixed in through the gravel. Now, our city is a democratic run, drug riddled, cesspool. We pay for garbage bags, and they pick up recycling twice a month...glass, cans, and newspapers. We used to be allowed to burn our waste paper, but the city took a pile of money from the EPA to make it illegal. I always felt that most recycling was counter intuitive. You waste a lot of water to wash out cans and glass jars. If you really care about the environment, quit drinking out of plastic bottles and get a water filter. Make coffee in a coffee pot, instead of K-cups. Buy food or products with less packaging. Buy quality products, so that you aren’t constantly buying new stuff that breaks quickly. Conservatism is all about being good stewards of your environment.
You are looking at this in a world that stops at the walls of the glass factory. Yes, if a truck of crushed glass shows up at their door, it is cheaper for them to use than raw materials, but how did it get there?
It starts as a jelly jar. When I empty it out, I could put the cap back on and throw it in the trash...but if I recycle it, lid off, its most definitely is getting washed. Again, it doesn’t matter how hot the furnace is, or how much stuff it burns off within the walls of the factory...the average consumer is unaffected by that and only cares about the bugs the jar attracts, and will waste the energy used to purify, lift (into tanks), and heat water, for each and every jar.
Then, my jelly jar travels in my car to a dumpster...usually carried in a disposable plastic bag, made from petroleum. On average, I drive a mile total out of my way to recycle around 20 lb of jars, a hundredth of a ton...at 20 mpg and $2.15, that’s $10.75 a ton just for me to get the jars to the dumpster, almost half the cost of delivered sand, but there is still a long journey ahead for my jelly jar.
Next, the county (which subsidizes this operation by forcing people to pay extra on their trash bill), hauls that dumpster around 20 miles to a sorting facility. The glass is not yet crushed, and is essentially 90% or more air, by volume, making for very inefficient trucking. The sorting facility, btw, is at the landfill - so if this glass had been in the trash, this would be the end of its travels and energy input. And there is added convenience, since they probably throw the green glass in the landfill anyway.
Once sorted, that same uncrushed, and very inefficient to haul, glass is taken to a crushing factory. I’m in Kansas...the closest factory is in Texas. If waste glass is a commodity, it stands to reason that this factory pays the same amount for local glass as they do for my glass that travels around 800 miles. Once again, the taxpayers in my county artificially pay the freight and cover the loss.
Then the crushing factory imparts energy to the jar, to pulverize it. I work in land development and have worked with economic development organizations - so I know that placing an environmental label on a facility gets good tax breaks. If I owned a cullet factory in Ft Worth, I’d shop for a better tax deal in Dallas and move there. In other words, it is more likely than not that the crushing factory is subsidized with local (and sometimes state) tax breaks that artificially prop up the industry.
And finally, the factory ships the crushed glass to the glass factory...probably a fairly short drive, but still requiring energy.
It is near impossibly to run the numbers on this...but I strongly suspect that the energy needed to do all this far exceeds the energy needed to suck some sand out of a hole and barge it to a glass factory...and if the market were unaltered by subsidies, this would be reflected in dollars as well. If there were a genuine market for this, I would get money for my jelly jars.