Incorporation of zinc in calcium sulfoaluminate cement clinker

Abstract

Several types of industrial wastes can be used as raw materials to obtain calcium sulfoaluminate (CSA) cement clinker. The first aim of this work was to define the maximum content of zinc that could be incorporated in CSA clinker in order to obtain the threshold limit. The second aim was to study the effect of CSA clinker composition on the threshold limits for zinc. Threshold limits for three CSA clinkers containing 25–75 wt% of ye'elimite were investigated. It was found that, beyond the defined threshold limits, the stability of ye'elimite and belite was not affected and the formation of a zinc oxide phase was detected. The threshold limit for zinc was identified to be 0.3 wt% for all the tested clinkers. Assessment of the reactivity of cements at the threshold limits was followed by calorimetric and compressive strength measurements. The results showed that the doped cements were at least as reactive as the reference cement.