Modifying Some Properties of Portland Cement Clinker and Portland Cement by Means of ZnO and ZnS.

Graduated amounts of ZnS or ZnO ( less than 4%) were added to laboratory clinkers (lime standard 95, silica modulus 2. 2, iron modulus 2. 0) before burning (2 hours at 1450 degree C). The burning behavior is favorably affected by the addition of ZnS or ZnO. Zinc is not vaporized, whereas sulphur is oxidized and largely vaporized. Zinc is incorporated into all four clinker phases, but in varying amounts.