**3.1 Raw material preparation**

HCFC slag is collected from **Shyam ferroalloys** Durgapur, West Bengal, India in the form of lumps. The lumps are crushed and ground in a ball mill, followed by sieving through mesh (size 240). The fine particles, thus obtained, are dried in an oven for 2 hrs at 120°C.

The alkaline activator used for preparation of Geopolymer (GP) is a combination of sodium silicate and sodium hydroxide in appropriate proportion. While preparing the solution mixture in a flask, it is kept on a hot plate with a magnetic stirrer. The alkaline liquid is prepared by mixing sodium silicate solution and sodium hydroxide solution. The solution is continuously stirred with a magnetic stirrer.

Plasticizer (SiKA) with extra water is poured to the liquid mixtures.
