scholarly journals Potential of Green Ceramics Waste for Alkali Activated Foams

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3563 ◽  
Author(s):  
Barbara Horvat ◽  
Vilma Ducman
Keyword(s):  
Low Cost ◽  
Alkali Activation ◽  
Activation Process ◽  
Foaming Agents ◽  
Insulating Material ◽  
X Ray ◽  
Thermal Insulating ◽  
Technical Ceramics ◽  
Body Residue ◽  
Alkali Activated

The aim of the paper is to research the influence of foaming and stabilization agents in the alkali activation process of waste green ceramics for future low cost up-cycling into lightweight porous thermal insulating material. Green waste ceramics, which is used in the present article, is a green body residue (non-successful intermediate-product) in the synthesis of technical ceramics for fuses. This residue was alkali activated with Na-water glass and NaOH in theoretically determined ratio based on data from X-ray fluorescence (XRF) and X-ray powder diffraction (XRD) that was set to maximise mechanical properties and to avoid efflorescence. Prepared mixtures were compared to alkali activated material prepared in theoretically less favourable ratios, and tested on the strength and density. Selected mixtures were further foamed with different foaming agents, that are Na-perborate (s), H2O2 (l), and Al (s), and supported by a stabilization agent, i.e., Na-dodecyl sulphate. The goal of the presented work was to prepare alkali activated foam based on green ceramics with density below 1 kg/l and compressive strength above 1 MPa.

scholarly journals Evaluation of Physical Properties of a Metakaolin-Based Alkali-Activated Binder Containing Waste Foam Glass

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5458
Author(s):  
Petra Mácová ◽  
Konstantinos Sotiriadis ◽  
Zuzana Slížková ◽  
Petr Šašek ◽  
Michal Řehoř ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Physical Properties ◽  
Foam Glass ◽  
Glass Production ◽  
Alkali Activation ◽  
Activation Process ◽  
X Ray ◽  
Thermal Insulating ◽  
The Matrix ◽  
Alkali Activated

Foam glass production process redounds to large quantities of waste that, if not recycled, are stockpiled in the environment. In this work, increasing amounts of waste foam glass were used to produce metakaolin-based alkali-activated composites. Phase composition and morphology were investigated by means of X-ray powder diffraction, Fourier-transform infrared spectroscopy and scanning electron microscopy. Subsequently, the physical properties of the materials (density, porosity, thermal conductivity and mechanical strength) were determined. The analysis showed that waste foam glass functioned as an aggregate, introducing irregular voids in the matrix. The obtained composites were largely porous (>45%), with a thermal conductivity coefficient similar to that of timber (<0.2 W/m∙K). Optimum compressive strength was achieved for 10% incorporation of the waste by weight in the binder. The resulting mechanical properties suggest the suitability of the produced materials for use in thermal insulating applications where high load-bearing capacities are not required. Mechanical or chemical treatment of the waste is recommended for further exploitation of its potential in participating in the alkali activation process.

scholarly journals Comparison of Surface and Structural Properties of Carbonaceous Materials Prepared by Chemical Activation of Tomato Paste Waste: The Effects of Activator Type and Impregnation Ratio

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Nurgul Ozbay ◽  
Adife Seyda Yargic
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Low Cost ◽  
Chemical Activation ◽  
Nitrogen Adsorption ◽  
Xrd Analysis ◽  
Point Of Zero Charge ◽  
Activation Process ◽  
X Ray ◽  
Tomato Paste

Activated carbons were prepared by carbonization of tomato paste processing industry waste at 500°C followed by chemical activation with KOH, K2CO3, and HCl in N2 atmosphere at low temperature (500°C). The effects of different activating agents and impregnation ratios (25, 50, and 100 wt.%) on the materials’ characteristics were examined. Precursor, carbonized tomato waste (CTW), and activated carbons were characterized by using ultimate and proximate analysis, thermogravimetric analysis (TG/DTG), Fourier transform-infrared (FT-IR) spectroscopy, X-ray fluorescence (XRF) spectroscopy, point of zero charge measurements (pHPZC), particle size analyzer, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, nitrogen adsorption/desorption isotherms, and X-ray diffraction (XRD) analysis. Activation process improved pore formation and changed activated carbons’ surface characteristics. Activated carbon with the highest surface area (283 m3/g) was prepared by using 50 wt.% KOH as an activator. According to the experimental results, tomato paste waste could be used as an alternative precursor to produce low-cost activated carbon.

New Thermal Insulating Material Based on Geocement

2013 ◽  
Vol 838-841 ◽  
pp. 183-187 ◽  
Author(s):  
Vít Petranek ◽  
Sergii Guzii ◽  
Pavel Krivenko ◽  
Konstantinos Sotiriadis ◽  
Anastasiia Kravchenko
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
External Heat ◽  
Great Scientist ◽  
Insulating Material ◽  
Average Temperature ◽  
Thermal Insulating ◽  
The Matrix ◽  
Birthday Anniversary ◽  
Alkali Activated

A new thermal insulating material was developed on the basis of a geocement, formulated as Na2OAl2O36SiO220H2O. Ground limestone and aluminosilicate pellets were used as fillers for its production (composition: geocement 64.29 wt. [%]; fillers 35.71 wt. [%]). This material, which is applied having a thickness of 3.0-4.5 mm, swells when it is exposed to an external heat flow of 1273 K average temperature. Swelling is due to the matrix phases and filler dehydration, which include heulandite, ussingite, sodium zeolite and other phases. As a result, a finely porous glassy aluminosilicate frame of jadeite-albite composition is formed, which is characterized by low thermal conductivity (0.09-0.175 Wm-1K-1). The developed material can be used to protect and to insulate wooden, metal and concrete surfaces from an one-sided heat source.The paper is dedicated to the great scientist of the XXI century in the field of alkali-activated cements and materials based on them, Pavlo Kryvenko, in honor of his 75thbirthday anniversary.

scholarly journals Recycled Waste Powders for Alkali-Activated Paving Blocks for Urban Pavements: A Full Laboratory Characterization

2019 ◽  
Vol 4 (4) ◽  
pp. 73 ◽  
Author(s):  
Piergiorgio Tataranni
Keyword(s):  
Raw Materials ◽  
Low Cost ◽  
Alkali Activation ◽  
Activation Process ◽  
Construction Technology ◽  
Laboratory Characterization ◽  
Visual Impact ◽  
Materials Used ◽  
Surrounding Landscape ◽  
Recycled Waste

Paving blocks are today a popular paving solution for urban surfaces. Considering the wide variety of products currently on the market, it is possible to build pavements that differ in terms of functionality, bearing capacity, skid resistance, visual impact, and aesthetic integration with the surrounding landscape. Interlocking concrete paving block is the most common construction technology considering its low cost and its easy installation. Different wastes and second-hand materials have recently been tested in order to completely or partially replace the raw materials used for the production of paving blocks. In this paper, a waste basalt powder is used for the production of alternative paving blocks through the alkali-activation process. Two different synthetic blocks were produced, with and without aggregates. Taking into account the EN 1338 standard for concrete paving blocks, a complete laboratory characterization is proposed for the two experimental blocks. Tests highlighted positive results and downsides that need to be optimized in order to convert the laboratory production to an industrial scale.

scholarly journals Use of Ceramic Sanitaryware as an Alternative for the Development of New Sustainable Binders

2015 ◽  
Vol 668 ◽  
pp. 172-180 ◽  
Author(s):  
Lucía Reig ◽  
M.V. Borrachero ◽  
J.M. Monzó ◽  
Holmer Savastano ◽  
Mauro M. Tashima ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Sanitary Ware ◽  
Pozzolanic Activity ◽  
Raw Material ◽  
Alkali Activation ◽  
X Ray ◽  
Amorphous Phases ◽  
Ceramic Sanitary Ware ◽  
Alkali Activated

Large amounts of ceramic sanitary-ware waste are generated in both the production process and construction and demolition practices. This waste contains amorphous phases that may react with the Portlandite that originates during Portland cement hydration or with an alkali solution, leading to a low CO2-binding material. This study investigated the pozzolanic activity of ceramic sanitary-ware waste, together with its potential to form new binders by alkali activation. For this purpose, raw material was characterized by X-ray diffraction, X-ray fluorescence, particle size distribution, thermogravimetry (TGA) and scanning electron microscopy (SEM). Percentages of ceramic waste of 15 wt.% and 25 wt.%, to replace Portland cement, were used to assess the pozzolanic behavior of this material, and samples were cured at 20oC for different curing times. Alkali-activated samples, in which Ca (OH)2 was used as a source of calcium, and NaOH and sodium silicate solutions were utilized as activators, were cured for 7 days at 65oC. The microstructural evolution of the developed binders was assessed in pastes by SEM and TGA analyses, and mortars were used to evaluate the compressive strength behavior. While some strength gain was observed due to pozzolanic activity, compressive strength values within the 14-36 MPa range were obtained in the alkali-activated mortars in accordance with the activator concentration and the percentage of Ca (OH)2 addition.

scholarly journals Alkaline Activation of Kaolin Group Minerals

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 268 ◽  
Author(s):  
Oliwia Biel ◽  
Piotr Rożek ◽  
Paulina Florek ◽  
Włodzimierz Mozgawa ◽  
Magdalena Król
Keyword(s):  
Sodium Hydroxide ◽  
Water Glass ◽  
Small Addition ◽  
Alkali Activation ◽  
Structural Studies ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Bulk Materials ◽  
X Ray ◽  
Alkali Activated

Zeolites can be obtained in the process of the alkali-activation of aluminosilicate precursors. Such zeolite–geopolymer hybrid bulk materials merge the advantageous properties of both zeolites and geopolymers. In the present study, the effect of the type and concentration of an activator on the structure and properties of alkali-activated metakaolin, and metahalloysite was assessed. These two different kaolinite clays were obtained by the calcination of kaolin and halloysite, and then activated with sodium hydroxide and water glass. The phase compositions were assessed by X-ray diffraction, the microstructure was observed via scanning electron microscope, and the structural studies were conducted on the basis of the infrared spectra. The structure and properties of the obtained alkali-activated materials depend on both the type of a precursor and the type of an activator. The formation of zeolite phases was observed when the activation was carried out with sodium hydroxide alone, or with a small addition of water glass, regardless of the starting material used. The higher proportion of silicon in the activator solution does not give crystalline phases, but only an amorphous phase. Geopolymers based on metahalloysite have better compressive strength as the result of the better reactivity of metahalloysite compared to metakaolin.

scholarly journals Adsorption performance of basic fuchsin on alkali-activated diatomite

2020 ◽  
Vol 38 (5-6) ◽  
pp. 151-167 ◽  
Author(s):  
Yong-Hua Zhao ◽  
Jin-Tao Geng ◽  
Jie-Chuan Cai ◽  
Yu-Fu Cai ◽  
Chun-Yan Cao
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Process ◽  
Textural Properties ◽  
Alkali Activation ◽  
Maximum Adsorption Capacity ◽  
Basic Fuchsin ◽  
Activation Temperature ◽  
X Ray ◽  
Adsorption Performance ◽  
Alkali Activated

The natural diatomite was treated with NaOH to obtain alkali-activated diatomite. The materials were systematically characterized by X-ray powder diffraction, X-ray fluorescence, Fourier transform infrared spectroscopic, scanning electron microscopy, and N2 adsorption–desorption. Meanwhile, the potential use of alkali-activated diatomite as adsorbent for the removal of basic fuchsin from aqueous solution was assessed by batch experiment. Results indicated that the structure and textural properties of diatomite were obviously changed via alkali activation, and then affecting its adsorption performance. The adsorption capacity of alkali-activated diatomite for basic fuchsin was higher than that of natural diatomite. In the case of alkali-activated diatomite, its adsorption capacity was increased with increasing the activation temperature, and the diatomite activated at 115°C (alkali-activated diatomite-115) exhibited the maximum adsorption capacity. The pseudo-first-order kinetics and the Sips isotherm model were preferable to describe the adsorption process of basic fuchsin on alkali-activated diatomite-115 and the thermodynamic parameters indicated that the adsorption process was endothermic and spontaneous.

New Rapid Setting Alkali Activated Cement Compositions

1989 ◽  
Vol 179 ◽  
Author(s):  
D. M. Roy ◽  
M. R. Silsbee ◽  
D. Wolfe-Confer
Keyword(s):  
Mechanical Property ◽  
Alkali Activation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Blended Cements ◽  
Setting Times ◽  
Rapid Setting ◽  
Alkali Activated ◽  
Alkali Activated Cement

AbstractThe advantage of utilizing blended cements for many applications has been well documented. However, the use of these materials has been limited by the longer setting times associated with the use of these materials. This report discusses the development of formulations employing alkali activation to shorten the setting times. The results of characterization of these materials using calorimetry, microscopic, x-ray diffraction, and mechanical property techniques are discussed.

scholarly journals Geopolymer/CeO2 as Solid Electrolyte for IT-SOFC

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 248 ◽  
Author(s):  
Jelena Gulicovski ◽  
Snežana Nenadović ◽  
Ljiljana Kljajević ◽  
Miljana Mirković ◽  
Marija Nišavić ◽  
...  
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Solid Electrolyte ◽  
Solid Phase ◽  
Low Cost ◽  
Energy Dispersive Spectrometer ◽  
Complex Impedance ◽  
Ionization Time ◽  
Calcined Clay ◽  
X Ray ◽  
Alkali Activated

As a material for application in the life sciences, a new composite material, geopolymer/CeO2 (GP_CeO2), was synthesized as a potential low-cost solid electrolyte for application in solid oxide fuel cells operating in intermediate temperature (IT-SOFC). The new materials were obtained from alkali-activated metakaolin (calcined clay) in the presence of CeO2 powders (x = 10%). Besides the commercial CeO2 powder, as a source of ceria, two differently synthesized CeO2 powders also were used: CeO2 synthesized by modified glycine nitrate procedure (MGNP) and self-propagating reaction at room temperature (SPRT). The structural, morphological, and electrical properties of pure and GP_CeO2-type samples were investigated by X-ray powder diffraction (XRPD), Fourier transform infrared (FTIR), BET, differential thermal and thermogravimetric analysis (DTA/TGA), scanning electron microscopy (FE-SEM), energy dispersive spectrometer (EDS), and method complex impedance (EIS). XRPD and matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) analysis confirmed the formation of solid phase CeO2. The BET, DTA/TGA, FE-SEM, and EDS results indicated that particles of CeO2 were stabile interconnected and form a continuous conductive path, which was confirmed by the EIS method. The highest conductivity of 1.86 × 10−2 Ω−1 cm−1 was obtained for the sample GP_CeO2_MGNP at 700 °C. The corresponding value of activation energy for conductivity was 0.26 eV in the temperature range 500–700 °C.

Experimental Study on Mechanical Properties and Micro-Mechanism of All-Solid-Waste Alkali Activated Binders Solidified Marine Soft Soil

2021 ◽  
Vol 1036 ◽  
pp. 327-336
Author(s):  
Ya Lei Wu ◽  
Jun Jie Yang ◽  
Si Chen Li ◽  
Man Wang
Keyword(s):  
Mechanical Properties ◽  
Solid Waste ◽  
Coal Fly Ash ◽  
Soft Soil ◽  
Deformation Modulus ◽  
Alkali Activation ◽  
Activation Process ◽  
Pozzolanic Materials ◽  
Alkali Activated Binders ◽  
Alkali Activated

Utilizing granulated blast furnace slag (GBFS), coal fly ash (FA), and furfural residue incineration ash (FRIA) as pozzolanic materials, then activated with calcium carbide residue (CCR) respectively to prepare all-solid-waste alkali activated binders (ASW binders). The laboratory tests were performed to research the effects of pozzolanic materials with different reactivity on the macro- and micro- characteristics of solidified marine soft soil. Results show that the mechanical properties and alkali-activation process of ASW binders solidified soil was determined mainly by the reactivity of pozzolanic materials, the higher reactivity of the pozzolanic materials in ASW binders couldn’t change the main hydration products, however, it would accelerate the hydrate reaction. The degree of hydrate reaction increased, the microstructure became denser with the increase of the reactivity of the pozzolanic materials in ASW binders solidified soil, on the macro- side, the strength and deformation modulus of the solidified soil increased, meanwhile, the brittleness of the solidified soil will be more obvious during the deformation resistance process. ASW binders (CCR:GBFS=1:1) solidified soil could reach the strength of cemented soil under the same conditions.

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