Irene García-Díaz

Bio: Irene García-Díaz is an academic researcher from Spanish National Research Council. The author has contributed to research in topics: Adsorption & Aqueous solution. The author has an hindex of 19, co-authored 59 publications receiving 1084 citations.

Ceramic wastes as alternative raw materials for Portland cement clinker production

Abstract: The cement industry has for some time been seeking procedures that would effectively reduce the high energy and environmental costs of cement manufacture. One such procedure is the use of alternative materials as partial replacements for fuel, raw materials or even clinker. The present study explores the reactivity and burnability of cement raw mixes containing fired red or white ceramic wall tile wastes and combinations of the two as alternative raw materials. The results showed that the new raw mixes containing this kind of waste to be technically viable, and to have higher reactivity and burnability than a conventional mix, providing that the particle size of the waste used is lower than 90 μm. The mineralogical composition and distribution in the experimental clinker prepared were comparable to the properties of the clinker manufactured with conventional raw materials. Due to the presence of oxides such as ZnO, ZrO 2 and B 2 O 3 in tile glazing, the content of these oxides was higher in clinker made with such waste. The mix of red and white ceramic wall tile waste was found to perform equally or better than each type of waste separately, a promising indication that separation of the two would be unnecessary for the purpose described above.

Supported liquid membranes technologies in metals removal from liquid effluents

Abstract: The generation of liquid effluents containing organic and inorganic residues from industries present a potential hazardousness for environment and human health, being mandatory the elimination of these pollutants from the respective solutions containing them. In order to achieve this goal, several techniques are being used and among them, supported liquid membranes technologies are showing their potential for their application in the removal of metals contained in liquid effluents. Supported liquid membranes are a combination between conventional polymeric membranes and solvent extraction. Several configurations are used: flat-sheet supported liquid membranes, spiral wounds and hollow fiber modules. In order to improve their effectiveness, smart operations have been developed: non-dispersive solvent extraction, non-dispersive solvent extraction with strip phase dispersion and hollow fiber renewal liquid membrane. This paper overviewed some of these supported liquid membranes technologies and their applications to the treatment of metal-bearing liquid effluents.

Clinkers and cements obtained from raw mix containing ceramic waste as a raw material. Characterization, hydration and leaching studies

Abstract: A clinker and a cement obtained from a raw mix containing ceramic waste as an alternative raw material were characterized in the present study. Their hydration, physical–chemical properties and leaching behaviour in different acid media were also explored. The findings showed that both the clinker and the cement met all the requirements set out in European standards EN 197-1 [1] , although they had higher ZnO, ZrO 2 , and B 2 O 3 contents than an industrially produced reference product. According to the hydration studies, initial hydration was somewhat retarded in the new cement, which exhibited longer initial and final setting times and lower 2-day mechanical strength. The SEM/BSE/EDS microstructural study showed, however, that morphologically and compositionally, the hydration products formed were comparable to unadditioned Portland cement paste products. While low concentrations of Zn and B were observed to leach in acid media, the biotoxicity trials conducted confirmed that these concentrations were not toxic. Zr was retained in the cement pastes.

Acidic Ionic Liquids.

Abstract: Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition.

Activated carbon from lignocellulosics precursors: a review of the synthesis methods, characterization techniques and applications.

Abstract: Activated carbon is a porous material that has been in many important ages of the human history. Lignocellulosic precursors and biomass sources have become important materials to produce it because their use produces many benefits, mainly environmental. Nowadays, it is possible to find numerous research papers devoted to the synthesis characterization and applications of novel precursors to produce activated carbon. Hence, special attention must be given to the relationship among the selected precursor characteristics, the final microstructure and properties of carbon. The present work provides a summary of research works outlining the use of lignocellulosic–based precursors to obtain activated carbons. A brief description of the characterization techniques for both, the precursors and activated carbons, comprising: physicochemical, micro/nanostructural, surface chemistry, textural and adsorption capacity features is presented. Finally, the application of these materials in adsorption of heavy metals, dyes, volatile organic compounds, gas storage and electrochemical capacitors is also included.

Measuring the eco-efficiency of cement use

Abstract: At present, the cement industry generates approximately 5% of the world’s anthropogenic CO2 emissions. This share is expected to increase since demand for cement based products is forecast to multiply by a factor of 2.5 within the next 40 years and the traditional strategies to mitigate emissions, focused on the production of cement, will not be capable of compensating such growth. Therefore, additional mitigation strategies are needed, including an increase in the efficiency of cement use. This paper proposes indicators for measuring cement use efficiency, presents a benchmark based on literature data and discusses potential gains in efficiency. The binder intensity (bi) index measures the amount of binder (kg m−3) necessary to deliver 1 MPa of mechanical strength, and consequently express the efficiency of using binder materials. The CO2 intensity index (ci) allows estimating the global warming potential of concrete formulations. Research benchmarks show that bi ∼5 kg m−3 MPa−1 are feasible and have already been achieved for concretes >50 MPa. However, concretes with lower compressive strengths have binder intensities varying between 10 and 20 kg m−3 MPa−1. These values can be a result of the minimum cement content established in many standards and reveal a significant potential for performance gains. In addition, combinations of low bi and ci are shown to be feasible.