The Use of Ceramic Waste Powder (CWP) in Making Eco-Friendly Concretes

The global production of ceramic waste powder (CWP), which is produced during the final polishing process of ceramic tiles, exceeds 22 billion tons. The disposal of CWP in landfills will cause significant environmental problems (i.e., soil, air, and groundwater pollution). CWP is characterized by its chemical composition that is mainly composed of silica (SiO2) and alumina (Al2O3). Both minerals represent more than 80% of the CWP composition. CWP has potentials to be used as an ingredient to partially or entirely replacing Portland cement to make eco-friendly concretes. This chapter summarizes the effect of using CWP in making eco-friendly concretes, with a particular focus on using CWP as a partial cement replacement in conventional-vibrated concrete (CVC) and self-compacting concrete (SCC), and the production of zero-cement alkali-activated concrete (AAC)

Synthesis and characterization of Cu-doped TiO2 thin films produced by the inert gas condensation technique

The bandgap of thin films Cu-doped TiO2 nanoclusters prepared using the inert gas condensation (IGC) technique have been investigated at various Cu contents. The samples were characterized using XRD, SEM/EDS and UV-visible spectrophotometer. It was found that doping of TiO2 thin film nanoclusters with Cu enhance its optical activity and shift it to the visible region; which makes it useful in photocatalytic applications. 1 Published under licence by IOP Publishing Ltd.Funded by UAE University (Project #: 31N093) and Emirates Foundation- Grant #: 2011/177 (UAE).Scopu

A Zero-Waste Process for the Treatment of Spent Potliner (SPL) Waste

This work presents a deep analyses of an environmentally friendly process to recover all valuable minerals contained in the spent potliner (SPL) such as graphite carbon and aluminum fluoride (AlF3) and production of sodium sulfate (Na2SO4) and gypsum (CaSO4) when H2SO4 is used as the leaching agent. The level of emission of hazardous gases such as HCN (weak acid) and HF are minimized by direct scrubbing of the HCN in aqueous AgNO3 solution to produce a stable silver cyanide (AgCN) product. The HF can be recovered as a liquid by condensation and used within the process and/or in production of metal fluorides such as the highly-soluble potassium fluoride (KF); a main source of fluoride in industry. Almost pure CO2 gas is also recovered from the process gas streams

Production of 1-Butyl-3-Methylimidazolium Acetate [Bmim][Ac] Using 1-Butyl-3-Methylimidazolium Chloride [Bmim]Cl and Silver Acetate: A Kinetic Study

Since most of the literature alternatives used to produce the ionic liquid 1-butyl-3-methylimidazolium acetate [Bmim][Ac] are very slow and require different solvents, we have used in this work a new process to produce the [Bmim][Ac] by the reaction of the ionic liquid 1-butyl-3-methylimidazolium chloride [Bmim]Cl with silver acetate (AgAc) where silver chloride (AgCl) precipitates as a by-product. The genuine experimental work and kinetic analyses presented here indicate that the reaction rate constant k = 7.67x1012 e(−79.285/RT). That is, the Arrhenius constant ko = 7.67x1012 L/mol.s and the activation energy Ea = 79.285 kJ/mol. The very high value of the Arrhenius constant indicates that the reaction of [Bmim]Cl with silver acetate to produce [Bmim][Ac] and silver chloride is extremely fast

Fiber-reinforcement and its effects on the mechanical properties of high-workability concretes manufactured with slag as aggregate and binder

The feasibility of manufacturing fiber-reinforced concretes of high workability through additions of high volumes of electric arc furnace steel slag is evaluated in this paper, using sustainable binders with ground granulated blast furnace slag and ladle furnace slag as a supplementary cementitious material. An extensive experimental plan is developed to test four (self-compacting and pumpable) concrete mixtures, some reinforced with 0.5% vol. of (metallic or synthetic) fibers, in both the fresh and the hardened state. Very specific mechanical aspects are examined, such as the evaluation of both longitudinal and transversal stress-strain compressive behavior, and the assessment of direct tensile strength through the “dog-bone” test. The results of testing this sustainable concrete design yielded suitable mechanical strengths, and good toughness, ductility and impact strength, among other properties. Good adhesion between the fibers and the cementitious matrix was also evident from the fiber pull-out test results. Finally, the overall results confirmed that the use of electric arc furnace steel slag can make a real contribution to construction-sector sustainability and that the mechanical behavior of these novel concretes meets the basic design requirements for use in real structures.Spanish Ministries MCI, AEI, EU and ERDF [RTI2018-097079-B-C31; 10.13039/501100011033; FPU17/03374]; the Junta de Castilla y León (Regional Government) and ERDF [UIC-231, BU119P17]; the Basque Government research group [IT1314-19]; Youth Employment Initiative (JCyL) and ESF [UBU05B_1274]; the University of Burgos [Y135.GI] and the University of the Basque Country [PPGA20/26]. Likewise, our thanks to CHRYSO and HORMOR for supplying the materials used in this research