Effect of fluorite addition on the reactivity of a calcined treated spent pot lining in cementitious materials

Treating SPL by the low caustic leaching and liming process generates an inert nonhazardous residue called LCLL Ash and a fluorite byproduct Calcined LCLL Ash that is ground into a fine powder demonstrates pozzolanic behavior in cement. The effect of the calcination temperature and fluorite byproduct addition on the reactivity of LCLL Ash was studied by the compressive strength activity index, Frattini test and Rilem R³ tests followed by XRD analysis. At 800°C, the formation of nepheline causes alkali uptake, the LCLL Ash showed a slightly lower reactivity with 10% fluorite addition. At 1000°C, calcined LCLL Ash/CF showed a better amorphization of phases and increasing reactivity due to reactions between fluorite and sodium oxide. Unlike LCLL Ash, no delay in hydration or hydro reactivity was observed with calcined LCLL Ash/CF.