Georgakopoulos, EvangelosManovic, Vasilije2017-03-222017-03-222017-02-21Georgakopoulos E, Santos RM, Chiang YW, Manovic V. (2017) Two-way valorization of blast furnace slag: synthesis of precipitated calcium carbonate and zeolitic heavy metal adsorbent. Journal of Visualized Experiments, Volume 120, Article number e550621940-087Xhttp://dx.doi.org/10.3791/55062http://dspace.lib.cranfield.ac.uk/handle/1826/11640The aim of this work is to present a zero-waste process for storing CO2 in a stable and benign mineral form while producing zeolitic minerals with sufficient heavy metal adsorption capacity. To this end, blast furnace slag, a residue from iron-making, is utilized as the starting material. Calcium is selectively extracted from the slag by leaching with acetic acid (2 M CH3COOH) as the extraction agent. The filtered leachate is subsequently physico-chemically purified and then carbonated to form precipitated calcium carbonate (PCC) of high purity (<2 wt% non-calcium impurities, according to ICP-MS analysis). Sodium hydroxide is added to neutralize the regenerated acetate. The morphological properties of the resulting calcitic PCC are tuned for its potential application as a filler in papermaking. In parallel, the residual solids from the extraction stage are subjected to hydrothermal conversion in a caustic solution(external) (2 M NaOH) that leads to the predominant formation of a particular zeolitic mineral phase (detected by XRD), namely analcime (NaAlSi2O6∙H2O). Based on its ability to adsorb Ni2+, as reported from batch adsorption experiments and ICP-OES analysis, this product can potentially be used in wastewater treatment or for environmental remediation applications.enAttribution 3.0 Internationalhttp://creativecommons.org/licenses/by/3.0/Blast furnace slagwaste valorizationCO2 utilizationmineral carbonationhydrothermal conversionheavy metal adsorptionprecipitated calcium carbonatezeoliteArticle