6 Conversion of Large Scale Wastes into Value-added Products
1.1.4 economics
While the issues outlined previously are important in their own right, they also
affect the economics of production. Some of the economic benets are linked to
lower energy requirements as in the case of aluminium recycling. Compared to steel
making from iron ore, its production from scrap leads to economic benets arising
from 74% reduction in energy requirement and 40% reduction in water requirement
(Arbatov). In the cement sector as well, economic benets are obtained with the
use of waste biomass based fuels instead of coal, and use of waste (y ash, slag)
as partial substitute for clinker thus saving on energy required for clinker produc-
tion (Lafarge, 2008). ...