| Autor: |
Moreno-Maroto JM; Department of Geology and Geochemistry, Faculty of Sciences, Autonomous University of Madrid, Cantoblanco, 28049 Madrid, Spain.; Department of Chemical, Environmental and Materials Engineering, Higher Polytechnic School of Linares, Scientific and Technological Campus of Linares, University of Jaén, 23700 Linares, Spain., González-Corrochano B; Department of Chemical, Environmental and Materials Engineering, Higher Polytechnic School of Linares, Scientific and Technological Campus of Linares, University of Jaén, 23700 Linares, Spain., Martínez-Rodríguez AM; Department of Statistics and Operations Research, Campus of Las Lagunillas, University of Jaén, 23071 Jaén, Spain., Conde-Sánchez A; Department of Statistics and Operations Research, Campus of Las Lagunillas, University of Jaén, 23071 Jaén, Spain., Cobo-Ceacero CJ; Department of Chemical, Environmental and Materials Engineering, Higher Polytechnic School of Linares, Scientific and Technological Campus of Linares, University of Jaén, 23700 Linares, Spain., Alonso-Azcárate J; Department of Physical Chemistry, Faculty of Environmental Sciences and Biochemistry, University of Castilla-La Mancha, Avenida Carlos III, s/n, 45071 Toledo, Spain., Uceda-Rodríguez M; Department of Chemical, Environmental and Materials Engineering, Higher Polytechnic School of Linares, Scientific and Technological Campus of Linares, University of Jaén, 23700 Linares, Spain., López AB; Department of Chemical, Environmental and Materials Engineering, Higher Polytechnic School of Linares, Scientific and Technological Campus of Linares, University of Jaén, 23700 Linares, Spain., Martínez-García C; Department of Chemical, Environmental and Materials Engineering, Higher Polytechnic School of Linares, Scientific and Technological Campus of Linares, University of Jaén, 23700 Linares, Spain., Cotes-Palomino T; Department of Chemical, Environmental and Materials Engineering, Higher Polytechnic School of Linares, Scientific and Technological Campus of Linares, University of Jaén, 23700 Linares, Spain. |
| Abstrakt: |
The effect of the addition of Fe 0 and Fe 3+ on the formation of expanded clay aggregates was studied using iron-free kaolin as an aluminosilicates source. Likewise, the incorporation of cork powder as a source of organic carbon and Na 2 CO 3 as a flux in the mixtures was investigated in order to assess its effect in combination with the iron phases. An experimental protocol, statistically supported by a mixture experiments/design of experiments approach, was applied to model and optimize the bloating index, density, absorption capacity, and mechanical strength. The process of expansion and pore generation and the associated decrease in density required the addition of iron, such that the optimum mixtures of these properties presented between 25 and 40 wt.% of Fe 0 or Fe 3+ , as well as the incorporation of 3.5-5 wt.% of organic carbon. The addition of Fe 3+ produced a greater volumetric expansion (max. 53%) than Fe 0 (max. 8%), suggesting that the formation of the FeO leading to this phenomenon would require reducing and oxidizing conditions in the former and the latter, respectively. The experimental and model-estimated results are in good agreement, especially in the aggregates containing Fe 0 . This reinforces the application of statistical methods for future investigations. |
