Based upon the analysis the first component of the ZAP-C 3 system accomplishes the extraction of free Ca from the BOS slag, the conversion of BOS slag to volumetrically stable aggregate and formation of an alkaline carbonate solution. The second component of the ZAP-C 3 system accomplishes the permanent sequestration of CO2 into CaCO3 and re-conversion of the alkaline solution to neutral water for use in the first component of the ZAP-C 3 system. Overall the ZAP-C 3 system can be described as a process for conversion of two waste material (BOS slag and CO2) into two valuable products (CaCO3 and volumetrically stable aggregate) that represent permanent sequestration of CO2: