Abstract:
This study investigated on leaching behavior of Zn from mortar derived from co-burning in cement process
by modified Toxicity Charact~ristic Leaching Procedure(TCLP). Ordinary clinker, clinker with zinc oxide,
and clinker with zinc-containing waste addition were prepared by incinerating all compositions at 1450 ?C
for 120 minutes. Experimental results illustrated that zinc at 0.1 % by weight slightly affected the properties
of clinker and cement mortar. However, as the zinc composition increased to 2.0 % by weight, the free lime
decreased whereas the tricalcium aluminate. As a consequence, the cement mortar had higher compressive
strength but lower porosity. The results from TCLP test revealed that the mortar with 2.0 % zinc by weight
complied with the heavy metal leaching standard of the US. EPA. At 2.0% zinc by weight contamination level,
the leachates obtained from the deionized water extraction of the mortars mixed the zinc oxide and zinc-containing
waste contained 0.21 and 0.13 mg/I of zinc, respectively, which were lower than the drinking water standard of
the Department of Health notified in RE. 2543. In addition, it was found that zinc could be leached out more
intensively as the leachant volume used in the Static Extraction Test and the acidity of the leachant used in the
General Acid Neutralizing Capacity Test increased. Therefore, an appropriate leaching test is required before
applying the cement contaminated with zinc in field practice.