Last Updated: Jan 17, 2017 Views: 156
The principle challenge with making glass successfully from coal ash is the relatively high percentage of aluminum oxide (Al2O3) and iron oxide (Fe2O3) that is present. The aluminum oxide increases the temperature needed to melt and form the glass, and requires adjustments be made to the amount of other ingredients added to the recipe. The iron oxide will make the glass black or very dark green.
The use of coal ash, as well as ash from incinerators, and land-based power plants, as an ingredient in glass making has been studied extensively over the years. The folks at our Library here can help you make contact with librarians at technical libraries (such as the Scholes Library at Alfred University) who can help you find resources in that area.