Attributional and consequential life cycle inventory assessment of recycling copper slag as building material in Singapore

This work is an attributional and consequential life cycle inventory assessment on the use of copper slag as a replacement for ordinary Portland cement. Assessments were done with respect to the emissions of seven kinds of heavy metals and four types of gaseous emissions. It was found that replacing cement with copper slag will reduce the emissions of cobalt, carbon dioxide, carbon monoxide and nitrogen oxides. However, it will increase the emissions of cadmium to the environment. This substitution may also reduce the emissions of arsenic, chromium, copper, lead, mercury and sulphur dioxide. In addition, three scenarios of likely consequences of this substitution were considered. It was found that these consequences will reduce the life cycle benefits of such a material substitution. Finally, four policy-making lessons were delineated.