Cost assessment in sustainable waste management

Waste Management

Ghiban, a. & Moldovan, P. (2009). Structural characterization of some new glass ceramics from industrial wastes. DAAAM 20(1): 1539.

Glass ceramics are widely used in industry because they have properties that are suitable for specific uses. Glass ceramics are "fine-grained polycrystalline materials formed when glasses of suitable compositions are heat treated and thus undergo controlled crystallization to the lower energy, crystalline state," (Ghiban & Moldovan 2009). Most of the glass ceramics being used in industry are purpose-designed and manufactured.

However, certain types of industrial waste can be used to manufacture glass ceramics. The use of industrial waste in the production of glass ceramics may represent a sustainable method of processing waste. Not only are the by-products of industry recycled, but also the further manufacture of new glass ceramic products is minimized. Research into the potential for turning industrial waste into glass ceramics can therefore be important in a number of different industries.

The chemical composition of glass ceramics manufactured with industrial waste products may raise questions about toxicity and safety. The current research investigates the toxicity of recycled glass ceramics and explores the cost effectiveness of using industrial waste to manufacture glass ceramics for industry.

Typically, glass ceramics are made of high purity raw materials like silica. In the manufacturing of glass ceramics from industrial waste, other materials of lower grade are used. This research focuses on three types of industrial waste that can be turned into glass ceramics: fly ash, mixed quality soda-lime-silica; mixed boron waste; and furnace-metallurgical slag produced after Fe-Ni production. From these raw materials, the researchers manufactured three types of glass ceramics. The three types of glass ceramics produced contained different proportions of CaO. Vitrification is the process used to transform the waste products into glass ceramics.

The three types of glass ceramics were then analyzed for structural integrity and thus, viability for use in industry. Methods of analysis include optic and SEM, which help determine qualities like glassiness. Results showed that larger amounts of CaO in the vitrification process changed the termperature at which crystallization takes place. By increasing the CaO amount in the glass ceramics, a higher cooling temperature during the crystallization process is needed. This may have cost implications for the manufacture of the glass ceramics.