Optimization of the Geopolymer Obtaining Process to Immobilize Mercury and Its Mechanical Evaluation

2. Faculty of Process Engineering, Polymer Research Group, National University of San Agustín Arequipa, Perú

Abstract: The objective of this work was to form a geopolymer based on pumice stone and kaolin treated thermally, basic activating solution with sodium silicate solution (Na2SiO3.nH2O) in order to immobilize solid mining waste (SMW). The influence of various physical factors during its elaboration and the response of the formed Geopolymer with the SMW previously stabilized were determined. The predominant physical factor evaluated was the resistance to compression, according to ASTM C-1157 method, which is a determining factor in the durability of the formed geopolymers. The results show a maximum of 34.70 MPa in a randomized treatment with levels (1:1, 8 and 60) of the studied factors and a minimum of 12.49 MPa with the factors (3:1, 4 and 20). The percentage ratio of the optimal geopolymerizing material formed to immobilize mercury present in the residue was 55% pumice stone, 45% metakaolin with a liquid/solid ratio of 0.4 and 10 Molar concentration of basic solution. This aluminosilicate synthetic material could well replace other materials. A complete factorial design with three central tests was used, applying the Statigraphics Centurion XVI software.