Glass deposites - from waste to resource!
In Kingdom of Crystal in Sweden there are ca 40 glasswork landfills that can provide resources as glass and lead. The project has developed a technique that separates lead, arsenic and antimony from deposited lead crystal glass. The result is glass and metal that can be reused for new products.
In southern part of Sweden there are more than 100 old glass works with landfills in the region Kingdom of Crystal. Approximately 40 of these are high risk landfills and have to be excavated. An inventory of 22 glassworks in the county administrative boards of Kalmar and Kronoberg showed that the total amount of glass is more than 100 000 m3 and that the content of arsenic is 600 tons, cadmium 40 tons and lead 3200 tons.
RISE Glass has developed a melt-separation technique for lead glass fulfilling the goal of less than 0,1% lead in the remaining glass. The technique also decreases the amount of arsenic and antimony within the glass but not cadmium. The technique has been verified for up to 6 kg of glass. It is only applicable for glass with lead content of at least a percent.
The remining glass can be used for new glass and the metals lead, arsenic and antimony can be purified and used as raw materials in the metal industry. The glass from the process has a low quality and could only be used as a filling material. The project developed a concept for stabilizing the glass.
It is beneficial with a high melting temperature and a long process times to reduce the lead content of the resulting glass. Two separate phases are achieved, a glass phase on top and a metal phase below. Additions are necessary for an efficient process and to obtain a glass with good properties suitable for further use.
The produced glass will be colored as a result of the input of colored glass and that impurities will remain from the glass sorting process. The most likely area of usage is in construction components and a minor amount as art glass. The metal phase can for example Boliden purify for further usage.
The technique has to be verified in larger scale, so someone will invest in a production unit. It Is most efficient if the glass directly is formed into products. The future industry will both use the melt-separation technique and produce glass products.
The melt-separation technique can be generalized and used on other lead containing glasses as cathode ray tubes and specialty glass. Glass from today´s art glass production that is deposited could also be re-melted in a full-size industry as well as unleaded glass from the excavations sites and other waste glass streams.
Glass - from waste to resource!
RISE role in project
Projektleder and technique developer
Målerås Glasbruk AB, Nybro Kommun