Patents

The invention relates to a method for production of paving blocks using waste materials such as Argon-Oxygen Decarburization (AOD) slag and Induction Furnace Slag (IFS), by the process of geopolymerization. In the method of invention milled IFS slag has been used which supplements alumina required for geopolymerization to AOD slag and also possesses higher reactivity. The fine particles of the slags undergo faster dissolution whereas the coarse particles partly undergo dissolution with addition of alkali activator such as hydroxide or silicates of sodium or potassium. This mixture of AOD slag, IFS slag and alkali solution is shaped into desired shapes either by vibration casting or by compression. For the geopolymerization reaction, the shaped articles are cured in the temperature range of 20-80 °C. The obtained paving blocks involving such a method are of high compressive strength, good volume stability and good abrasion resistance.