Synthesis and characterization of geopolymers containing blends of unprocessed steel slag and metakaolin: The role of slag particle size

The present research deals with production and characterization of geopolymers prepared by mixing of metakaolin, a steel slag from the production of chromium-manganese steel, a commercial sodium silicate solution and a sodium hydroxide solution. Materials were prepared mixing metakaolin with different proportions of steel slag (20, 40, 60, 80wt%) with different maximum particle size. Materials containing metakaolin and steel slag alone were also prepared for comparison. It has been observed that the use of fine steel slag powders leads to develop the best performances and that composition containing 40wt% steel slag and 60wt% metakaolin revealed the best overall behaviour.