Search results for "Geopolymer"
showing 10 items of 32 documents
Beeswax/halloysite microparticles embedded within a geopolymeric layer for the protective coating of steel
2023
A halloysite-based geopolymer filled with microwax particles was designed as a protective layer on steel substrates. Beeswax microparticles were obtained from the clay stabilized Pickering emulsions and they were homogeneously dispersed within the geopolymeric network, thus improving the coating physico-chemical properties. Specifically, this treatment changed the steel's wettability by increasing its hydrophobicity. Moreover, XRF analysis was conducted in order to have details on the chemical compositions.
Application of differently treated illite and illite clay samples for the development of ceramics
2017
Abstract This study represents the results of investigations on the possible geopolymer formation of an alkali, mechanically and thermally (including hydrothermally) activated 2:1 layer silicate, namely, illite and illite clay, for low-temperature ceramic products. The main starting materials were Quaternary illite clay samples taken from the Apriki–Laza pit in Latvia. For the investigations, an intermediate composition of illite clay and separated illite were used. The following research methods for the treated illite and illite clay were used: the phase transition was analysed by differential thermal analysis, while the phase compositions, microstructures and structures were analysed by X…
Removal of ammonium from municipal wastewater with powdered and granulated metakaolin geopolymer
2017
Abstract Ammonium (NH₄⁺) removal from municipal wastewater poses challenges with the commonly used biological processes. Especially at low wastewater temperatures, the process is frequently ineffective and difficult to control. One alternative is to use ion-exchange. In the present study, a novel NH4+ ion-exchanger, metakaolin geopolymer (MK-GP), was prepared, characterised, and tested. Batch experiments with powdered MK-GP indicated that the maximum exchange capacities were 31.79, 28.77, and 17.75 mg/g in synthetic, screened, and pre-sedimented municipal wastewater, respectively, according to the Sips isotherm (R² ≥ 0.91). Kinetics followed the pseudo-second-order rate equation in all case…
Halloysite based geopolymers filled with wax microparticles as sustainable building materials with enhanced thermo-mechanical performances
2022
This work proposes a novel protocol for the fabrication of halloysite based geopolymers filled with beeswax microparticles obtained from Pickering emulsions. The actual filling of the microwax into the geopolymers has been demonstrated by using several techniques, including thermal analyses, spectroscopies, microscopies and contact angle experiments. According to the morphological and structural investigations, microwax spherical particles (diameter ranging between ca. 3 and 5 μm) have been homogeneously dispersed within the geopolymeric network conferring excellent properties to the hybrid geopolymers in terms of mechanical performances and heat storage capacity although their low content …
Novel biomass fly ash-based geopolymeric mortars using lime slaker grits as aggregate for applications in construction: Influence of granulometry and…
2019
Abstract This work discusses the influence of the aggregate granulometry and the binder/aggregate ratio on the engineering properties of novel green geopolymeric mortars. Two wastes generated by a Portuguese Kraft pulp industry are employed to manufacture the material: lime slaker grits (used as aggregate) and biomass fly ash (to partially replace the metakaolin − 70 wt% substitution). The novel geopolymeric mortars could find innovative applications as sustainable construction materials. The studied mix design foresees the use of several grits granulometric ranges and ratios binder/aggregate to discuss workability, water sorptivity, and mechanical performance of the novel mortars. To date,…
Multi criteria evaluation of a sustainable alkali-activated concrete
2019
The construction industry is one of the most polluting sectors worldwide. In order to reduce the environmental footprint, novel green materials and processes are being considered by valorising and reusing wastes. This work investigates the production of a novel and sustainable geopolymeric concrete reusing biomass fly ash from kraft paper-pulp industry. In particular, this paper aims to evaluate the best combination of the aggregate granulometry used in the material production. For this purpose, the multicriteria method TOPSIS has been implemented in order to obtain a rank of the concrete specimens. In this approach only mechanical aspects have been considered and future developments will i…
Innovative Recycling of Lime Slaker Grits from Paper-Pulp Industry Reused as Aggregate in Ambient Cured Biomass Fly Ash-Based Geopolymers for Sustain…
2019
Lime slaker grits and biomass fly ash are solid wastes produced by the Kraft paper-pulp industry that are commonly disposed of in landfill. However, recent studies and European regulations discourage such disposal practices. This work investigates an alternative and innovative way to recycle and reuse these wastes in the production of green geopolymeric mortars intended for application in the construction industry. Here, biomass fly ash was used as the main source of alumino-silicate in the binder precursor (70 wt.% substitution to metakaolin), and grits (ranging from 1&ndash
Selection of novel geopolymeric mortars for sustainable construction applications using fuzzy topsis approach
2020
Construction is recognized as one of the most polluting and energy consuming industries worldwide, especially in developing countries. Therefore, Research and Development (R&
Sulphate removal over barium-modified blast-furnace-slag geopolymer
2016
Blast-furnace slag and metakaolin were geopolymerised, modified with barium or treated with a combination of these methods in order to obtain an efficient SO4(2-) sorbent for mine water treatment. Of prepared materials, barium-modified blast-furnace slag geopolymer (Ba-BFS-GP) exhibited the highest SO4(2-) maximum sorption capacity (up to 119mgg(-1)) and it compared also favourably to materials reported in the literature. Therefore, Ba-BFS-GP was selected for further studies and the factors affecting to the sorption efficiency were assessed. Several isotherms were applied to describe the experimental results of Ba-BFS-GP and the Sips model showed the best fit. Kinetic studies showed that th…
Sulphate removal over barium-modified blast-furnace-slag geopolymer
2016
Blast-furnace slag and metakaolin were geopolymerised, modified with barium or treated with a combination of these methods in order to obtain an efficient SO42− sorbent for mine water treatment. Of prepared materials, barium-modified blast-furnace slag geopolymer (Ba-BFS-GP) exhibited the highest SO42− maximum sorption capacity (up to 119 mg g−1) and it compared also favourably to materials reported in the literature. Therefore, Ba-BFS-GP was selected for further studies and the factors affecting to the sorption efficiency were assessed. Several isotherms were applied to describe the experimental results of Ba-BFS-GP and the Sips model showed the best fit. Kinetic studies showed that the so…