Examinando por Autor "Uceda, Manuel"
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Ítem Can statistical methods optimize complex multicomponent mixtures for sintering ceramic granular materials? A case of success with synthetic aggregates(ELSEVIER, 2023-07-15) Moreno-Maroto, José Manuel; Conde-Sánchez, Antonio; González-Corrochano, Beatriz; Uceda, Manuel; Martínez-García, Carmen; Cobo-Ceacero, Carlos Javier; Martínez-Rodríguez, Ana María; Alonso-Azcárate, Jacinto; López-García, Ana Belén; Cotes, TeresaThe relationship between the proportions of multicomponent mixtures with the technological properties of ceramic granular materials (synthetic aggregates) has been studied using statistical methods. The four phases involved in the formulations have been: kaolin (K) as aluminosilicate source; cork powder (C) as organic carbon source; sodium carbonate (N) as flux and pyrite (P) as source of iron and sulfur. The Mixture Experiments - Design of Experiments (ME-DOE) has been the statistical methodology applied from the initial configuration of the 36 starting formulations to the final validation of the models and optimums. After granulation, artificial aggregates have been obtained by sintering in a rotary kiln, and their main technological properties have been determined. Bloating index (BI), particle density (ρrd), water absorption (WA24) and crushing strength (S) were selected as the four key characteristics to be modeled and optimized, using response surface and effect plots to assess the effect of K, C, N and P on such properties. 32 out of 36 starting varieties met the density criteria for lightweight aggregates. In the optimum formulations obtained, the minimum percentage of K was 83 wt%, so that the variations in the percentages of P, C and N were the critical variables for determining the final properties of the aggregate. The contrast between experimental and estimated data has shown that the models fit adequately, indicating that this type of approach may have enormous potential for future research on artificial aggregates and other ceramic materials.Ítem Dataset of "Analyzing the Role of Fe0 and Fe3+ in the Formation of Expanded Clay Aggregates"(2023-08-14) Moreno-Maroto, José Manuel; González-Corrochano, Beatriz; Martínez-Rodríguez, Ana María; Conde-Sánchez, Antonio; Cobo-Ceacero, Carlos Javier; Alonso-Azcárate, Jacinto; Uceda, Manuel; López-García, Ana Belén; Martínez-García, Carmen; Cotes, TeresaÍtem Dataset of "Can statistical methods optimize complex multicomponent mixtures for sintering ceramic granular materials? A case of success with synthetic aggregates"(2023-07-15) Moreno-Maroto, José Manuel; Cobo-Ceacero, Carlos Javier; Martínez-Rodríguez, Ana María; Conde-Sánchez, Antonio; González-Corrochano, Beatriz; Alonso-Azcárate, Jacinto; Uceda, Manuel; López-García, Ana Belén; Martínez-García, Carmen; Cotes, TeresaÍtem Dataset of "Study of the synergistic impact of Fe3O4, Na2CO3 and organic C on kaolin-based lightweight aggregates by a DOE (Mixture Experiments) approach"(2023-11-03) Moreno-Maroto, José Manuel; Cobo-Ceacero, Carlos Javier; Martínez-Rodríguez, Ana María; Conde-Sánchez, Antonio; González-Corrochano, Beatriz; Alonso-Azcárate, Jacinto; Uceda, Manuel; López-García, Ana Belén; Martínez-García, Carmen; Cotes, TeresaÍtem Eco-efficient transformation of mineral wool wastes into lightweight aggregates at low firing temperature and associated environmental assessment(ELSEVIER, 2022-08-22) López-García, Ana Belén; Uceda, Manuel; León-Gutiérrez, Sara; Cobo-Ceacero, Carlos Javier; Moreno-Maroto, José ManuelWaste recycling is one of the key elements to mitigate the environmental problems that threaten our society. Mineral wool is currently the most widely used insulation material in the European Union, so the amount of waste generated in the demolition and restoration of buildings has increased alarmingly. This work investigates for the first time the use of glass wool (GW) and rock wool (RW) as a component in the manufacture of lightweight aggregates, showing that both can be suitable raw materials considering the density (1.3–1.5 g/cm ) and mechanical strength (2–6 MPa) obtained. In addition, the use of GW would help to reduce the firing temperature significantly (700 °C) compared to that normally used in the manufacture of these materials (around 1200 °C), which would imply significant energy savings. Considering that thermal insulation materials and lightweight aggregates are among the most widely used materials in the construction sector, the work presented here also evaluates the environmental impact associated with the manufacture of lightweight aggregates with RW and GW in comparison with the traditional process, using the Life Cycle Assessment (LCA) methodology. A significant environmental improvement has been observed in almost all the analyzed impact categories of the artificial aggregates manufactured with mineral wool with respect to traditional LWAs.Ítem Effect of the addition of organic wastes (cork powder, nut shell, coffee grounds and paper sludge) in clays to obtain expanded lightweight aggregates(ELSEVIER, 2023) Cobo-Ceacero, Carlos Javier; Moreno-Maroto, José Manuel; Guerrero-Martínez, Marta; Uceda, Manuel; López-García, Ana Belén; Martínez-García, Carmen; Cotes, TeresaFour organic solid wastes (coffee grounds, ground nut shell, paper money sewage sludge and cork powder) have been investigated as bloating inducing agents in lightweight aggregate (LWA) manufacturing when mixed in small proportions (2.5 wt.%) with three types of clays. The pellets obtained were fired in a rotary kiln at the maximum feasible temperature for 4 min. A similar impact was observed both in the working conditions and in the properties of the LWAs, showing that the differences between said residues are not as decisive as those of the clays to which they are added. The organic wastes have played a crucial role in achieving reducing conditions inside the aggregate. Thus, their addition has led to substantial improvements both from an operational point of view, lowering the working temperature, and from a technological perspective, favoring bloating and the development of a highly porous and lightweight structure. Leachate studies have shown that the LWAs meet the regulatory limits. The outcomes of this investigation show that, in line with the precepts of the Circular Economy, the recovery of organic wastes of different nature can have a place in the production of environmentally friendly LWAs.Ítem Recycling of ‘alperujo’ (olive pomace) as a key component in the sintering of lightweight aggregates(ELSEVIER, 2019-12) Uceda, Manuel; Cobo-Ceacero, Carlos Javier; Martín-Lara, María Ángeles; López García, Ana Belén; Moreno-Maroto, José Manuel; Cotes, Teresa; Calero, Mónica; Martínez -García, CarmenThe current environmental problems that threaten our society can only be mitigated with a radical change in the paradigm of production and consumption. Recycling waste is a key element in this. This work has focused on the valorization of a widely spread agricultural waste: the so-called ‘alperujo’ (olive pomace). For the first time, olive pomace (OP) has been used as a component in the manufacture of lightweight aggregates (LWAs). Mixtures with 0, 1.25, 2.5, 5 and 10 wt% OP have been prepared from three different clays. The research results show that the addition of OP in low proportions (mainly 2.5%) is more positive to achieve aggregate bloating, pore formation and a lighter structure. The high calorific value of OP also helps to reduce the firing temperature significantly, which would result in energy savings. In the same way, bloating would be favored with the increase of the time and the temperature, especially with this last one. The materials obtained have excellent properties. In addition, the study of leachate in the most expanded aggregate shows that the concentration of heavy metals is very low, representing no danger to the environment. According to these findings, the recycling of olive pomace can be an excellent alternative in the manufacture of LWAs.Ítem Study of the synergistic impact of Fe3O4, Na2CO3 and organic C on kaolin-based lightweight aggregates by a DOE (Mixture Experiments) approach(Elsevier, 2023-11-03) Moreno-Maroto, José Manuel; Cobo-Ceacero, Carlos Javier; Martínez-Rodríguez, Ana María; Conde-Sánchez, Antonio; González-Corrochano, Beatriz; Alonso-Azcárate, Jacinto; Uceda, Manuel; López-García, Ana Belén; Martínez-García, Carmen; Cotes, TeresaThe compositional synergies involved in the thermal formation of lightweight aggregates (LWAs) have been investigated through four pure phases: non-expansive kaolin (K); cork powder (C); sodium carbonate (N) and magnetite-Fe3O4 (M). Mixture Experiments has been applied for formulation, modeling and optimization. LWAs have been manufactured from 36 starting mixtures and the main technological properties have been characterized: bloating index (BI), particle density (ρrd), water absorption (WA24) and crushing strength (S). Maximum BI and WA24 together with minimum density are associated with the addition of a significant amount of iron phase in combination with small proportions of organic carbon (Optimal [BI > 60%]: 56.0% K + 40.2% M + 3.9% C + 0% N), while S increases antagonistically with expansion. Iron reduction by incomplete combustion of C appears to be critical in pore formation and concomitant bloating. N has enhanced the sphericity of the expanded specimens. The contrast between experimental and estimated data has shown that the models have generally performed very well.