However, conduction calorimetric experiments have shown that
the milling atmosphere has a bearing on the reactivity of slag despite their similarity in particulate characteristics;
CO2-milled slag has been found to be more reactive than the air-milled slag. Both air and CO2-milled slag has
been found good geopolymerization behavior leading to high compressive strength of the geopolymer products;
higher compressive strength values for the geopolymer prepared from the latter further shows its enhanced reactivity
over the former. TCLP tests of the prepared samples confirm that the release of toxic metals is within
USEPA limits and hence the process is an environment friendly way of utilizing the zinc slag.