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Calcium phosphate (CaP) with several chemical compositions and morphologies was prepared by precipitation using aqueous solutions of L-Glutamic acid (H2G) and calcium hydroxide, both mixed together with an aqueous solution (0.15 M) of phosphoric acid. Plate-shaped dicalcium phosphate dihydrate (brushite) particles were obtained and identified at a lower concentration of the solution of the reactants. The Ca/P ratio deduced by EDS was ~1, as expected. The nanoscale dimension of carbonate apatite and amorphous calcium phosphate, with variable Ca/P ratios, were revealed by X-ray diffraction (XRD) and scanning electron microscopy and energy dispersive X-ray spectroscopy analysis (SEM-EDS). They were characterized in medium and high concentrations of calcium hydroxide (0.15 M and 0.20 M). The equilibria involved in all the reactions in aqueous solution were determined. The thermodynamic calculations showed a decrease in the amount of chelate complexes with an increase in pH, being the opposite of [CaPO4-] and [CaHG+]. This fluctuation showed an evident influence on the morphology and polymorphism of CaP particles obtained under the present experimental conditions, with potential use as a biomaterial.

The cement manufacturing industry is one of the main greenhouse gas emission producers and also consumes a large quantity of raw materials. It is essential to reduce these emissions in order to comply with the Paris Agreement and the principles of the circular economy. The objective of this research was to develop different types of cement clinker blends using industrial waste and innovative design to produce low-energy cement. Several types of waste have been studied as alternative raw materials. Their main characteristics have been analyzed via X-ray fluorescence (XRF), X-ray diffraction (XRD), Attenuated total reflectance Fourier trans-form infrared spectroscopy (ATR-FTIR), thermal analysis (TG-DTG-DSC) and scanning electron microscopy and energy dispersive X-ray spectroscopy analysis (SEM-EDS). The results obtained from the experimental work carried out in this research focused on the study of crude blends for low-energy cement created from industrial waste. The effect of the addition of different industrial waste types, as a substitution for raw materials, in the production of low-energy cement with high dicalcium silicate content has been investigated. Thus, the dosage design has been performed using modified Bogue equations and quality indexes (LSF, AM, and SM). The calculations of both the modified Bogue equations and quality indexes necessitate knowledge of the weight percentages of CaO, SiO2, Al2O3, and Fe2O3, determined via XRF. In this theoretical design of the different blends, it has been established that a dicalcium silicate ratio of 60-65 wt % and an LSF of 78-83% as the limit are values common to all of them. The calculation basis for the crude blends has been based on calcined materials. Therefore, the chemical composition was established, following this premise. Thus, it was possible to develop cement clinker blends with compositions of 50 wt % and 100 wt % using industrial wastes. This research has shown that the clinkerization process is one of

Drying kinetics of olive stone and olive-tree pruning, two important biomasses from olive culture, was experimentally assessed at six different temperatures (from 343 K to 393 K) and four sample thicknesses (from 15 to 50 mm). Analysis of the drying curves revealed that Page's model was suitable for predicting the drying characteristics of both solid biofuels. From this analysis, two new mathematical equations to describe the dependence of moisture ratio with temperature and drying time were also proposed. The values of effective water diffusivity, calculated at the falling rate period by using Fick's second law of diffusion, increased when increasing drying temperature and sample thickness. Diffusivities for olivetree pruning (3.41 108 e 32.5 108 m2 /s) were almost twice higher than those for olive stone (1.87 108 e 16.4 108 m2 /s).

Industrially manufactured ceramic bricks have a negative effect on the environment due to both the depletion of natural resources and the CO2 emis- sions resulting from the considerable amount of energy used in their production. Recently, diverse waste or subproducts from different industrial processes have been used to improve the performance of ceramic materials, giving rise to the creation of the «ecobrick». In this study, we present the results obtained from experiments using various biomass waste products to create a porous network capa- ble of modifying the properties of traditional bricks to adapt them to modern technical requirements. 19 type of brick were manufactured with the addition of 6 biomass subproducts: rice husks (C), almond husks (CA), olive stones (HA), olive leaves (HO), olive wood (LO) and pruning waste from olive trees (PO). These materials were added to a conventional clay mix in three different proportions (7.5 %, 15 % and 25 %) and three different particle size distributions (0/1 mm, 1/2 mm and 0/2 mm). The results show that particle size does not affect the performance (physical and mechanical) of the ecobricks. However, performance was negatively affected in proportion to the amount of biomass waste added to the mix, without this undermining the normal functionality of the bricks. In fact, a considerable improvement was observed in the thermal conductivity of the ecobricks. This was true particularly, and surprisingly, of the mix containing the lowest proportion of additional material., El ladrillo cerámico como material de construcción industrial contribuye negativamente al deterioro del medioambiente, tanto por el agotamiento de los recursos naturales como por la elevada cantidad de energía necesaria para su fabricación, que se traduce en emisiones de CO2. La incorporación de productos residuales o subproductos procedentes de diversos procesos industriales ha dado lugar a los denominados «ecoladrillos». En este trabajo de investigación se estudia el comportamiento de ladrillos cerámicos con la incorporación de diferentes biomasas residuales con la función de generar una red porosa que modifique sus propiedades para adaptarlos a los requerimientos técnicos actuales. Para ello se han fabricado 19 tipos de ladrillos con la incorporación de 6 subproductos biomásicos: cascarilla de arroz (C), cáscara de almendra (CA), hueso de aceituna (HA), hoja de olivo (HO,) leña de olivo (LO) y poda de olivo (PO). Las biomasas se han incorporado a una arcilla convencional en tres proporciones en volumen (7,5 %, 15 % y 25 %), con tres tamaños de distribución de partícula (0/1 mm, 1/2 mm y 0/2 mm). Los resultados obtenidos muestran que el tamaño de partícula no ha condicionado el comportamiento físico y mecánico de los ecoladrillos, no así la proporción de biomasa, aunque en ningún caso se ha comprometido la normal funcionalidad de los mismos. Por el contrario, se ha observado una mejora considerable en la conductividad térmica de los ecoladrillos fabricados, fundamentalmente, con los menores porcentajes de reemplazo.