Geopolymerization of solid waste of non-ferrous metallurgy - A review

The growing demand for non-ferrous metals (Aluminium, Copper, Nickle, Lead and Zinc) has grown the non-ferrous metallurgical industry, which generate huge amount of solid waste. Most common method for the disposal of these solid wastes is dumping at sites, which pollutes the soil and water and covers the useful land. Geopolymerization technique can be very helpful for the safe disposal of these solid wastes, which converts the solid wastes into valuable construction materials such as binders, mortar, bricks, paving blocks and concrete etc. However, to commercialize the use of these construction products, some key aspects require detailed examination. Alternative techniques and materials will have to be identified to increase their reactivity in geopolymerization and in-depth knowledge of reaction mechanism, mix design, strength and durability characteristics of resulting geopolymer will have to be studied. The present paper reviews the important studies on geopolymerization of different solid wastes produced from non-ferrous industry. The optimum synthesis parameters such as alkali activators, curing temperature, curing time and molar ratio etc. for the geopolymerization of these solid wastes are reported and exiting gaps and future trends are also discussed.