There are very large amounts of copper tied up in wiring which is not in use or surplus, but this copper is sheathed in plastic and/or rubber, which is very difficult to remove manually. Burning generates hazardous gases, so I was wondering if an effective and efficient pyrolysis process has ever been developed for removing wire insulation? I live near a site that was proposed for the pyrolytic processing of old tires, and the backers assured the locals that the process would not be environmentally hazardous. Given the value of copper, the energy costs of pyrolysis might be acceptable.
There are two common methods for stripping insulation for recycling. One is a chipper-type machine that chops it all up into small pieces and automatically sorts out the copper. For really long pieces, there are stripper machines that can handle a variety of gauges.
Burning would be a waste of fuel compared to those, not to mention cleaning the waste fumes.
If you browse around YouTube for lessons on recycling copper, some will tell you to not try burning off the insulation as some scrap dealers refuse to take that. (Dealers grade wire based on the thickness of the copper, relative proportion of insulation, etc. The better the grade the more you get per pound.)
I’m not aware of anything, chemically, to prevent a pyrolytic or combustion (not the same thing) process. It just comes down to economics.
This was the first journal article I stumbled on:
Pyrolysis of most carbon based things produces compounds that are very environmentally unfriendly. Compounds like Benzene, phenols, and in the case of PVC (wire insulation) will have chlorinated compounds.
So apart from using all the energy for pyrolysis, there is the added capital investment and operating costs of gas cleanup. It wouldn’t be economically feasible in the US, but countries with lax environmental laws may allow it.
Combustion again will require investment in flue gas treatment because like most plastics, you will get dioxin in the combustion products.
At the top of the pricing charts is what’s called ‘bare bright.’ Not surprisingly, that’s clean, unoxidized, shiny Cu.
I used to strip wires with a formic acid goo which worked a treat, but I don’t know if this would be economical or safe for large amounts of wire.