Glass Recycling Question....

Most recycling centers don't recycle glass anymore because the economics don't support it (transportation costs greatly outweigh the value of the glass which is mostly sand and there is no energy saving as opposed to recycling aluminum). There is some local use of crushed recycled glass as aggregate in asphalt paving but that's not a high volume requirement.

Glass container manufacturers in UK use recycled glass.It requires a lot less energy to re-melt, and a mix can contain up to 60% recycled glass.

Since the mass of the glass being melted is the same as the original raw materials mixture and the melting temperature is the same, how can the energy savings be that significant?

Glass is made up of sand and minor additives. If you want your glass to be evenly coloured, it has to stay in the furnace and be correctly mixed. This takes time. If the raw material is made up of 60% the right colour, then it mixes quicker and less energy is used.

The paper and glue is cleaned some first but not completely off the glass because at 2000-2200 degrees the furnace vaporizes anything that is flammable instantly and it usually just floats on top of molten glass for a second or two until it is burned completely up. On my small 55 lb. glass furnace I like to feed it with cullet which made up from old broken lime soda glass or new pre-melted nuggets of glass instead of batch which is a lime, soda and sand mix. We store the glass cull-et outside and uncovered for sometimes over a year and when needed just load it straight into the furnace without even rinsing the dust, dirt, mold or anything else off first and it does not affect the glass at all.

Once a glass is colored I know of no way to get the color out and if you mix different colored glass together in the same melt you will end up with a nasty grayish colored glass. I save only the clear glass scrap for re-melting. Color glass is made by adding some type of metal oxides to the batch during the melting process. iron oxide will give olive green glass, gold will give ruby red, cobalt will make dark sapphires and cobalt blue colors, nickle will give amber glass tones and so on. Once this is consumed into the glass melt and the color is set I would think that it is impossible or at least not worth the trouble to remove the color from the glass.

You can get those Kevlar cut resistant gloves to handle broken glass with and some of these gloves have a good bit of heat Resistance as well. We have been going through a safety issue with people getting cuts while using the utility razor knifes where I work. i guess one4 day we will just quit using any kind of knife at the mill

I understand the high heat would but things quickly. But you say they actually vaporize? No ash by-product at all?

Story goes that if you fell into a live glass furnace, all that would come out would be the steel toe caps off your boots! Don't know if its a fact, and don't really want to try it out either!

You are correct flesh and bones would not have much of a chance in a 2150 degree environment. I never get any ash out of my glass crucible anything I throw into it the furnace just slides around on the molten glass surface until it is totally consumed. I think the steel toes in your boots would also melt away as well and just give the glass a nasty greenish tint.

A few metals can stand that kind of heat and not oxidize or degrade rapidly. (stuff like inconel, platinum. 310 stainless, tungsten carbide etc) I was reading about a water cooled furnace that was made from tungsten carbide and used graphite elements that could go up to 3500 degrees F and I think this is getting to the limits of all but a very few materials that can handle this kind of heat.

The thermo couple I use in my furnace is a R-type made from one platinum and one platinum with 10% rhodium wire and all of this is set into a Tantalum sleeve. the wire is 22 gauge and the probes are 12" long but cost 586.00 each. the platinum is unaffected by the 2150 temps.

I picked up the wrong end of a red hot stainless steel blow pipe once and although it did not take me very long to drop it the damage had been done as 3rd degree burns over most of my hand. I can not imagine being thrown into a furnace but i am sure you would not last very long.

I found a somewhat morbid video online of where a glassblowers shop cat had died and he cremated him in his glory hole or re-heat furnace which runs at about 1800-2000 degrees and after a little while there was only a few table spoons of ash left and after an hour there was nothing left at all. i am not sure if it blew away in the smoke or just disappeared somehow but it was gone.

I have a friend that gets his cullet in the form broken ware from large glass companies. He throws all the glass dust dirt, bugs grass and pieces of the card board container that has rotted away straight into his furnace and produces nearly flawless glass pieces from it.