Precipitated calcium carbonate (PCC), a filler and pigment material, is typically produced by calcining limestone at high temperature processes and by re-carbonating the formed calcium oxide in an aqueous solution. This process causes significant carbon dioxide emissions, while it enables particle size and quality control during processing. An alternative PCC production method named Slag2PCC, where steel converter slag is used as a calcium source instead of limestone, has been recently developed at Finnish universities. When these methods are compared by means of a cradle-to-gate life cycle assessment (LCA), it is confirmed that the Slag2PCC approach has negative CO2 emissions, i.e. the process captures more CO2 than what is generated. Also, regarding other studied LCA impact categories, human health, ecosystem quality and resources, the alternative method is more environmentally benign. However, if excessive after-treatment processes are required for e.g. purifying the produced PCC, the new approach will pollute more than the traditional PCC manufacturing.
- Calcium carbonate
- Steel converter slag