156 results on '"Yliniemi, J."'
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2. Production of ceramic construction materials as an environmental management solution for sulfidic mine tailings
- Author
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Paiva, H., Simões, F., Maljaee, H., Yliniemi, J., Illikainen, M., and Ferreira, V. M.
- Published
- 2021
- Full Text
- View/download PDF
3. Pulverization of fibrous mineral wool waste
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Yliniemi, J., Laitinen, O., Kinnunen, P., and Illikainen, M.
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- 2018
- Full Text
- View/download PDF
4. Alkali activation of iron-rich fayalite slag:fresh, hardened and durability properties
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Illikainen, M. (Mirja), Yliniemi, J. (Juho), Adediran, A. I. (Adeolu Idowu), Illikainen, M. (Mirja), Yliniemi, J. (Juho), and Adediran, A. I. (Adeolu Idowu)
- Abstract
Fayalite slag (FS) is an Fe-rich by-product generated during non-ferrous metallurgy refining processes. Currently, the annual global production of FS is 58 million tons, and this is likely to increase soon due to the increasing demand for non-ferrous metals for varied applications. Regrettably, only a small fraction of FS is utilized in low value applications with most of it ending up in landfills. The aim of this thesis is to fully utilize FS as precursor for alkali-activated materials (AAMs). AAMs are alternative cementitious materials that could provide environmental benefits compared to Portland cement concrete. Although FS contains a large amount of iron (>50%) and low amounts of calcium, aluminium, and amorphous material compared to blast furnace slag, which is a commonly used AAM precursor, the results of this thesis show that this low reactive material can be used as a sole precursor (aggregate and binder source) for AAMs. Furthermore, the mineralogical investigation of different particle size fractions of FS revealed a variation in the amorphous content. Fine fractions of FS had a higher amorphous content, and this resulted in higher reactivity and better mechanical and microstructural properties compared to the coarse fractions of FS. AAMs containing FS as an aggregate and binder had superior mechanical and microstructural properties compared to those containing standard sand as aggregates. Further optimization of the particle size distribution and elevated temperature curing improved the properties of FS-based AAMs. To avoid the use of curing at elevated temperatures, the incorporation of co-binders into the FS matrix was investigated as a means to improve the properties of FS-based AAMs at an ambient temperature and facilitate their practical application. The incorporation of co-binders significantly modified the gels formed and improved the fresh, hardened and durability properties of FS-based AAMs when exposed to different aggressive environme, Tiivistelmä Fayaliittikuona on ei-rautametallien jalostusprosesseissa syntyvä rautapitoinen sivutuote. Tällä hetkellä fayaliittikuonaa tuotetaan maailmanlaajuisesti 58 miljoonaa tonnia, ja määrän odotetaan kasvavan ei-rautametallien kysynnän lisääntyessä erilaisissa sovelluksissa. Vain pieni osuus fayaliittikuonasta pystytään hyödyntämään vähäarvoisissa sovelluksissa suurimman osan päätyessä kaatopaikoille. Tämän väitöskirjan tavoitteena on hyödyntää fayaliittikuonaa kokonaisvaltaisesti alkaliaktivoitujen materiaalien (AAM) raaka-aineena. AAM:t ovat vaihtoehtoisia sementtipohjaisia materiaaleja, jotka voivat tarjota ympäristöhyötyjä portlandsementtibetoniin verrattuna. Fayaliittikuona sisältää suuren määrän rautaa (>50 %) ja vähän kalsiumia, alumiinia sekä amorfista ainetta verrattuna masuunikuonaan, joka on yleisesti käytetty AAM:ien raaka-aine. Tämän väitöskirjatyön tulokset kuitenkin osoittavat, että tätä matalareaktiivista fayaliittikuonaa voidaan käyttää sekä aggregaattina että sideaineena AAM-laasteissa. Lisäksi fayaliittikuonan eri kokojakeiden mineraloginen tutkimus paljasti vaihtelua amorfisessa aineen määrässä. Pienien fayaliittikuonapartikkelien amorfinen pitoisuus oli korkeampi kuin isojen partikkelien, mikä johti pienen kokojakauman korkeampaan reaktiivisuuteen sekä sideaineen parempiin mekaanisiin ja mikrorakenteellisiin ominaisuuksiin. Fayaliittikuona sisältää suuren määrän rautaa (>50 %) ja vähän kalsiumia, alumiinia sekä amorfista ainetta verrattuna masuunikuonaan, joka on yleisesti käytetty AAM:ien raaka-aine. Tämän väitöskirjatyön tulokset kuitenkin osoittavat, että tätä matalareaktiivista fayaliittikuonaa voidaan käyttää sekä aggregaattina että sideaineena AAM-laasteissa. Lisäksi fayaliittikuonan eri kokojakeiden mineraloginen tutkimus paljasti vaihtelua amorfisessa aineen määrässä. Pienien fayaliittikuonapartikkelien amorfinen pitoisuus oli korkeampi kuin isojen partikkelien, mikä johti pienen kokojakauman korkeampaan reaktiivisuuteen sekä sidea
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- 2023
5. Enhancing the thermal stability of alkali-activated Fe-rich fayalite slag-based mortars by incorporating ladle and blast furnace slags:physical, mechanical and structural changes
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Adediran, A. (Adeolu), Yliniemi, J. (Juho), Moukannaa, S. (Samira), Ramteke, D. D. (D. D.), Perumal, P. (Priyadharshini), Illikainen, M. (Mirja), Adediran, A. (Adeolu), Yliniemi, J. (Juho), Moukannaa, S. (Samira), Ramteke, D. D. (D. D.), Perumal, P. (Priyadharshini), and Illikainen, M. (Mirja)
- Abstract
A proper and detailed understanding of the thermal stability of Fe-rich fayalite slag-based alkali-activated materials (AAMs) is important due to their potential use in refractory and fire-resistant applications. Here, fayalite slag (FS) was used as the main precursor for AAMs. The effects of incorporating ladle slag (LS) or blast furnace slag (BFS) and different temperature exposures up to 1000 °C were investigated through visual observation, compressive strength, ultrasonic pulse velocity (UPV), thermal conductivity, x-ray diffraction (XRD), thermogravimetry and differential scanning calorimetry (TG/DSC), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope coupled with electron probe microanalyzer (SEM-EPMA). The experimental results indicated that the incorporation of LS or BFS as additional calcium and aluminum sources positively affected the high-temperature behavior of blended mortars, which exhibited a reduction in voids, cracks, and thermal shrinkage while having higher residual strength and thermal stability than solely FS-based AAMs. This was mainly due to the differences in mineralogical transformation and the phases formed. Interestingly, the joint effect of elevated temperature exposure and the addition of LS or BFS enhanced the formation of more stable crystalline phases and densified the structure of blended mortars at 1000 °C.
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- 2023
6. Revisiting alkali-activated and sodium silicate-based materials in the early works of Glukhovsky
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Ponomar, V. (Vitalii), Luukkonen, T. (Tero), Yliniemi, J. (Juho), Ponomar, V. (Vitalii), Luukkonen, T. (Tero), and Yliniemi, J. (Juho)
- Abstract
This review article provides an overview of Glukhovsky’s Soil Silicates (1952), a seminal work that remains untranslated into English, and explores its relevance in the context of modern alkali-activated materials. Surprisingly, certain materials, methods, and approaches mentioned by Glukhovsky have received limited attention in subsequent literature. Motivated by occasional shortages and high costs of Portland cement, Glukhovsky investigated the utilization of local raw materials, including soils and industrial wastes, as solid precursors for producing sodium silicate binders, which he termed soil silicates. Glukhovsky’s early studies primarily focused on utilization of natural materials such as loess, sandy loam, river sand, silt sand, loam, and brown clay. This review article summarizes the key factors influencing the mechanical properties of soil silicates, encompassing the modulus and concentration of sodium silicate, variations in particle size and chemical compositions of solid precursors, and curing methods. A comprehensive analysis of these findings reveals that the materials identified as soil silicates by Glukhovsky encompassed multiple consolidation mechanisms that extended beyond the modern definition of alkali-activated materials.
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- 2023
7. Recycling high volume Fe-rich fayalite slag in blended alkali-activated materials:effect of ladle and blast furnace slags on the fresh and hardened state properties
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Adediran, A. (Adeolu), Yliniemi, J. (Juho), Lemougna, P. N. (Patrick N.), Perumal, P. (Priyadharshini), Illikainen, M. (Mirja), Adediran, A. (Adeolu), Yliniemi, J. (Juho), Lemougna, P. N. (Patrick N.), Perumal, P. (Priyadharshini), and Illikainen, M. (Mirja)
- Abstract
The valorization of Fe-rich fayalite slag (FS) as a precursor for alkali-activated materials (AAMs) is hampered by its low reactivity at ambient temperature. Here, FS was blended with waste-based reactive co-binders such as ladle slag (LS) and blast furnace slag (BFS) to improve the fresh and hardened state properties of the AAMs for potential construction applications. The results showed that the incorporation of LS and BFS as an additional source of Ca and Al accelerated the reaction kinetics and influenced the binder gel type and formation mechanism. In all the mixes, Fe, Si and Na are present in the evolving binder gel. In addition to these elements, the binder gel of the blended formulations is also rich in higher quantities of Ca and Al and showed possible formation of C-A-S-H and C-(N)-A-S-H together with the development of andradite, a calcium ferrosilicate hydrate phase formed from chemical interaction between FS and co-binders; it indicates that both FS and co-binder participated in the binder gel formation. Furthermore, the nucleating and filling effects of co-binders improved the workability, ultrasonic pulse velocity and mechanical properties; this also densified the structure and lowered the water absorption and permeable porosity of the blended mortars. The compressive strength of blended mortars was above 20 MPa, thus satisfying the strength requirements of building materials according to ASTM C62. The results of this study emphasize the reuse potential of FS with other waste streams in producing eco-friendly AAMs, which can have a wide range of construction applications.
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- 2023
8. Utilization of green liquor dreg in lightweight aggregates:effect of texture on physical properties
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Adesanya, E. (Elijah), Yliniemi, J. (Juho), Kinnunen, P. (Paivo), Finnilä, M. (Mikko), Illikainen, M. (Mirja), Adesanya, E. (Elijah), Yliniemi, J. (Juho), Kinnunen, P. (Paivo), Finnilä, M. (Mikko), and Illikainen, M. (Mirja)
- Abstract
Green liquor dreg (GLD) is a side stream generated by pulp industry. Due to its complex physicochemical nature, it has been reported to be difficult material to utilize. Here, a novel approach towards utilization of moist and dry green liquor dreg as binder and filler in alkali-activated lightweight artificial aggregates was developed. Dried GLD and moist GLD were granulated with blast furnace slag (BFS) and Bioash in different mixtures using alkali activation. The effect of the GLD nature (dried and moist) on strength, microstructure and durability of the lightweight granules were determined and compared. Results show that the method used in homogenizing the moist GLD and other powders was efficient and improved the frost resistance. The reaction product identified in the granule’s includes calcium silicate hydrate, Mg–Al layered double hydroxides, and ettringite. These results demonstrate the potential of GLD as a binder and fillers in cementitious applications.
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- 2023
9. Durability of alkali-activated Fe-rich fayalite slag-based mortars subjected to different environmental conditions
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Adediran, A. (Adeolu), Yliniemi, J. (Juho), Carvelli, V. (Valter), Adesanya, E. (Elijah), Illikainen, M. (Mirja), Adediran, A. (Adeolu), Yliniemi, J. (Juho), Carvelli, V. (Valter), Adesanya, E. (Elijah), and Illikainen, M. (Mirja)
- Abstract
Fe-rich alkali activated materials (AAMs) require detailed understanding of their durability prior to their real-life application in the construction industry. Three mixes were formulated with fayalite slag (FS) as the main precursor. The effect of incorporation of ladle slag (LS) or blast furnace slag (BFS) on the shrinkage and exposure to physical and chemical attacks representing environmental conditions in cold and tropical regions (acidic solution at room temperature and in freeze-thaw, combined sodium sulfate and sodium chloride solution at room temperature and in freeze-thaw, freeze-thaw in water and dry-wet cycles) was investigated via visual observation, mass loss, compressive strength, X-ray diffraction (XRD), mercury intrusion porosimetry (MIP), and scanning electron microscope coupled with energy dispersive X-ray spectroscopy (SEM-EDS). Experimental results show the considerable role of incorporated LS and BFS in modifying the gels formed and controlling material degradation of blended AAMs after exposure. In contrast, sole FS-based samples were completely degraded particularly those exposed to freeze-thaw in water, acid, and combined sodium sulfate and sodium chloride solution, indicating their vulnerability to frost and chemical attacks.
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- 2022
10. Comparison of one-part and two-part alkali-activated metakaolin and blast furnace slag
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Segura, I. P. (Isabel Pol), Luukkonen, T. (Tero), Yliniemi, J. (Juho), Sreenivasan, H. (Harisankar), Damø, A. J. (Anne Juul), Jensen, L. S. (Lars Skaarup), Canut, M. (Mariana), Kantola, A. M. (Anu M.), Telkki, V.-V. (Ville-Veikko), Jensen, P. A. (Peter Arendt), Segura, I. P. (Isabel Pol), Luukkonen, T. (Tero), Yliniemi, J. (Juho), Sreenivasan, H. (Harisankar), Damø, A. J. (Anne Juul), Jensen, L. S. (Lars Skaarup), Canut, M. (Mariana), Kantola, A. M. (Anu M.), Telkki, V.-V. (Ville-Veikko), and Jensen, P. A. (Peter Arendt)
- Abstract
One-part alkali-activated materials prepared with solid-form alkali activator are gaining attention in the construction industry, as they are an easier and safer approach for cast-in-situ applications in comparison with two-part approach (i.e., involving the use of alkali-activator solutions). The present study compares the one-part and conventional two-part mixing methods with two aluminosilicate precursors, metakaolin and ground granulated blast-furnace slag, using identical mix designs (in terms of molar ratios of SiO₂, Al₂O₃, and Na₂O) with both preparation methods. The results revealed that using one-part mix delays the setting time, increases the heat of reaction, decreases the shrinkage, and reaches between 80 and 85% of the compressive strength of the two-part mix. In addition, scanning electron microscopy, thermogravimetric analysis, and X-ray diffraction analysis showed no major differences between one- and two-part. However, energy-dispersive X-ray spectroscopy and magic angle spinning nuclear magnetic resonance experiments indicated that the extent of reaction in two-part alkali-activated mixes is higher than for one-part.
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- 2022
11. Characterization of an aged alkali-activated slag roof tile after 30 years of exposure to Northern Scandinavian weather
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Luukkonen, T. (Tero), Yliniemi, J. (Juho), Walkley, B. (Brant), Geddes, D. (Daniel), Griffith, B. (Ben), Hanna, J. V. (John V.), Provis, J. L. (John L.), Kinnunen, P. (Päivö), Illikainen, M. (Mirja), Luukkonen, T. (Tero), Yliniemi, J. (Juho), Walkley, B. (Brant), Geddes, D. (Daniel), Griffith, B. (Ben), Hanna, J. V. (John V.), Provis, J. L. (John L.), Kinnunen, P. (Päivö), and Illikainen, M. (Mirja)
- Abstract
Alkali-activated materials (AAMs) have been known as an alternative cementitious binder in construction for more than 120 years. Several buildings utilizing AAMs were realized in Europe in the 1950s–1980s. During the last 30 years, the interest towards AAMs has been reinvigorated due to the potentially lower CO₂ footprint in comparison to Portland cement. However, one often-raised issue with AAMs is the lack of long-term studies concerning durability in realistic conditions. In the present study, we examined a roof tile, which was prepared from alkali-activated blast furnace slag mortar and exposed to harsh Northern Scandinavian weather conditions in Turku, Finland, for approximately 30 years. Characterization of this roof tile provides unique and crucial information about the changes occurring during AAM lifetime. The results obtained with a suite of analytical techniques indicate that the roof tile had maintained excellent durability properties with little sign of structural disintegration in real-life living lab conditions, and thus provide in part assurance that AAM-based binders can be safely adopted in harsh climates. The phase assemblage and nanostructural characterization results reported here further elucidate the long-term changes occurring in AAMs and provide reference points for accelerated durability tests and thermodynamic modelling.
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- 2022
12. Dissolution-precipitation reactions of silicate mineral fibers at alkaline pH
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Ramaswamy, R. (Rajeswari), Yliniemi, J. (Juho), Illikainen, M. (Mirja), Ramaswamy, R. (Rajeswari), Yliniemi, J. (Juho), and Illikainen, M. (Mirja)
- Abstract
Silicate mineral fibers — stone (Sw) and glass wool (Gw) — are promising resources for cementitious binders. Insights gained from their dissolution kinetics under alkaline conditions can help to control the release of elements, formation of cementitious phases, and understand reactivity of similar type glasses (soda-lime and basalt). Decreasing the liquid-to-solid ratio (L/S) affects the dissolution rate of Sw, whereas the effect was lower for Gw. Residual rate observed for Sw was due to approaching equilibrium between the surface precipitates and solution chemistry. Two types of precipitation products were observed for both fibers at high pH: Mg-Al-Fe LDH and a C-N-(A-)S-H phase with a small concentration of Al. Dissolved Al was observed to incorporate more in LDH at a high L/S, whereas at a low L/S, Al incorporates more into C-N-(A-)S-H gel, altering its morphology. In addition, Ca-Ti-Si-rich globular domes, and Ca-Fe-Ti-rich nano-dome like hydrogarnets on the Sw fiber surfaces were observed.
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- 2022
13. An overview of the utilisation of Fe-rich residues in alkali-activated binders:mechanical properties and state of iron
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Ponomar, V. (Vitalii), Yliniemi, J. (Juho), Adesanya, E. (Elijah), Ohenoja, K. (Katja), Illikainen, M. (Mirja), Ponomar, V. (Vitalii), Yliniemi, J. (Juho), Adesanya, E. (Elijah), Ohenoja, K. (Katja), and Illikainen, M. (Mirja)
- Abstract
Iron-rich alkali-activated materials (Fe-AAM) are considered potential alternatives to ordinary Portland cement (OPC) to limit CO₂ emissions and convert several metallurgical wastes into useful products. Unlike conventional aluminosilicate alkali-activated systems in which the role of the precursor’s main constituents and the reaction products are well defined to some extent, the limited knowledge of the role and state of iron in AAMs restricts its utilisation in the construction sector. Nevertheless, several studies have shown the ability of iron to participate in the formation of alkali-activation reaction products, which induces high compressive strength (over 100 MPa) and provides both environmental and material performance benefits. In this study, we critically evaluate existing data on Fe-rich raw materials, activators, co-binders, mechanical properties, curing types and the reactivity and role of iron in Fe-AAMs.
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- 2022
14. Sustainable iron-rich cements:raw material sources and binder types
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Peys, A. (Arne), Isteri, V. (Visa), Yliniemi, J. (Juho), Yorkshire, A. S. (Antonia S.), Lemougna, P. N. (Patrick N.), Utton, C. (Claire), Provis, J. L. (John L.), Snellings, R. (Ruben), Hanein, T. (Theodore), Peys, A. (Arne), Isteri, V. (Visa), Yliniemi, J. (Juho), Yorkshire, A. S. (Antonia S.), Lemougna, P. N. (Patrick N.), Utton, C. (Claire), Provis, J. L. (John L.), Snellings, R. (Ruben), and Hanein, T. (Theodore)
- Abstract
The bulk of the cement industry’s environmental burden is from the calcareous source. Calcium is mostly available naturally as limestone (CaCO₃), where almost half of the mass is eventually released as CO₂ during clinker manufacture. Iron (Fe) is the fourth most common element in the Earth’s crust surpassed only by oxygen, silicon, and aluminium; therefore, potential raw materials for alternative cements can contain significant amounts of iron. This review paper discusses in detail the most abundantly available Fe-rich natural resources and industrial by-products and residues, establishing symbiotic supply chains from various sectors. The discussion then focusses on the impact of high iron content in clinker and on ferrite (thermo)chemistry, as well as the importance of iron speciation on its involvement in the reactions as supplementary cementitious material or alkali-activated materials, and the technical quality that can be achieved from sustainable Fe-rich cements.
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- 2022
15. Porous SB-Cu1 two-dimensional metal-organic framework:the green catalyst towards C—N bond-forming reactions
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Bagheri, S. (Sepideh), Esfanidiary, N. (Naghmeh), Yliniemi, J. (Juho), Bagheri, S. (Sepideh), Esfanidiary, N. (Naghmeh), and Yliniemi, J. (Juho)
- Abstract
The main advantage of metal-organic frameworks (MOFs) catalysts over other heterogeneous catalysts is that they can be designed to have reaction sites within molecularly well-defined and tunable structures to achieve high catalytic performance. In recent years, several types of metal-organic frameworks with copper(II) have been synthesized for a wide range of applications but there is still few reports for MOFs containing copper(I). Herein, the rod-like crystals SB-Cu1 were synthesized through coordination bonding of bbp ligand and CuI. Inside porous two-dimensional SB-Cu1 each Cu(I) center lies in a tetrahedral coordination sphere of pyridyl groups. This study demonstrates that SB-Cu1 with its desirable features: high porosity, open metal sites (Cu (I)) and benzimidazole (brønsted base) could play as a dual heterogeneous catalyst for C-N forming reactions to synthesize products in good to excellent yields(70–85%). In this work, ethanol as green solvent and a wide variety of imidazole, pyrrole, amine and aryl halide have been used for preparing products. Also, the MOF catalyst was recovered and reused at least five times without loss of activity.
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- 2022
16. Development of Sustainable Alkali-Activated Mortars Using Fe-Rich Fayalitic Slag as the Sole Solid Precursor
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Adediran, A. (Adeolu), Yliniemi, J. (Juho), and llikainen, M. (Mirja)
- Subjects
lcsh:HT165.5-169.9 ,Fe-rich fayalite slag ,aggregate ,lcsh:TA1-2040 ,alkali activation ,mortar ,interface region ,alkali-activated materials ,lcsh:City planning ,lcsh:Engineering (General). Civil engineering (General) ,binder ,ultrasonic pulse velocity - Abstract
Vast amounts of water-cooled non-ferrous metallurgy slags are generated yearly, and significant amounts are unutilized or dumped in landfills. To address this issue, in this study, MgO-FeOx-SiO₂ fayalitic slag (FS) was used as the sole solid precursor (as an aggregate and binder) in alkali-activated mortars. The performance of the mortar samples was analyzed in terms of workability, density, compressive strength, and ultrasonic pulse velocity. The microstructural properties and binder composition of the samples were studied using a scanning electron microscope (SEM) coupled with energy dispersive X-ray spectroscopy (EDS). Experimental results revealed that mortar samples made with FS aggregates performed better, achieving a 28-day compressive strength of 21 MPa compared to mortars produced with standard sand aggregates, which gained compressive strengths of 9 MPa. Further optimization of the particle size distribution of FS aggregate-based mortar samples using particle packing technology improved the workability, densified the mortar and yielded a mechanical performance of up to 40 MPa. FS aggregates have better interfacial bonding with the binder gel compared to standard sand, and the FS aggregates participate in the hardening reactions, consequently affecting the final binder phase composition, which consists of a Na₂O-Fe₂O₃-SiO₂ gel with lower quantities of CaO, MgO, and Al₂O₃. Therefore, the alkali-activated mortars produced based on the optimization of fully recycled industrial residues can provide a pathway for the sole utilization of metallurgical by-products, which can have a wide range of structural applications.
- Published
- 2021
17. Characterization of mineral wool waste chemical composition, organic resin content and fiber dimensions:aspects for valorization
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Yliniemi, J. (Juho), Ramaswamy, R. (Rajeswari), Luukkonen, T. (Tero), Laitinen, O. (Ossi), de Sousa, A. N. (Alvaro Nunes), Huuhtanen, M. (Mika), and Illikainen, M. (Mirja)
- Subjects
Vitreous fibers ,Fiber size ,Phenol-urea–formaldehyde resin ,Stone wool ,Glass wool ,eye diseases ,Mineral wool waste - Abstract
Despite mineral wool waste is only a small fraction of total construction and demolition waste (CDW) by mass, it requires large transportation and landfilling capacities due to its low bulk density, and its utilization remains low compared to other CDW types. It is essential to understand the physical and chemical properties of this waste fraction in order to utilize it, e.g. as fiber reinforcement in composites or as supplementary cementitious material. Here, we provide a chemical and physical characterization of 15 glass wool and 12 stone wool samples of different ages collected from various locations across Europe. In addition, the chemical compositions of 61 glass and stone wool samples obtained from the literature are presented. Glass wool samples show little variation in their chemical composition, which resembles the composition of typical soda-lime silicate glass. Stone wool presents a composition similar to basaltic glass but with variability between samples in terms of calcium, magnesium, and iron content. Potentially toxic elements, such as Cr, Ba, and Ni, are present in mineral wools, but in low concentrations (
- Published
- 2021
18. Antibacterial properties and cytotoxicity of 100% waste derived alkali activated materials:slags and stone wool-based binders
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Sgarlata, C. (Caterina), Dal Poggetto, G. (Giovanni), Piccolo, F. (Federica), Catauro, M. (Michelina), Traven, K. (Katja), Češnovar, M. (Mark), Nguyen, H. (Hoang), Yliniemi, J. (Juho), Barbieri, L. (Luisa), Ducman, V. (Vilma), Lancellotti, I. (Isabella), and Leonelli, C. (Cristina)
- Subjects
social acceptance ,stone wool ,cytotoxicity ,waste utilization ,alkali-activated materials ,antibacterial properties ,slag - Abstract
In this study we compare the leaching behavior and the antibacterial and cytotoxic properties of 100% slag or stone wool derived alkali activated materials. The antibacterial activity was measured as the inhibiting capacity against two Gram-negative bacterial strains, Escherichia coli and Pseudomonas aeruginosa and one Gram-positive bacterial strain: Enterococcus faecalis. The cytotoxicity properties were tested on mouse embryonic fibroblast NIH-3T3 cell-line. It was proved that the high quality of the 3D aluminosilicate network of the consolidated materials obtained from powders of CaO or MgO-rich slags or stone wool, opportunely activated with NaO and/or Na-silicate, was capable of stabilizing heavy metal cations. The concentrations of leachate heavy cations were lower than the European law limit when tested in water. The effect of additives in the composites, basal fibers or nanocellulose, did not reduce the chemical stability and slightly influenced the compressive strength. Weight loss in water increased by 20% with basalt fibers addition, while it remained almost constant when nanocellulose was added. All the consolidated materials, cement-like in appearance, exhibited limited antibacterial properties (viability from 50 to 80% depending on the bacterial colony and the amount of sample) and absence of cytotoxicity, envisaging good acceptance from part of the final consumer and zero ecological impact. CaO-rich formulations can replace ordinary Portland cement (showing bacterial viability at 100%) with a certain capability for preventing the reproduction of the E. coli and S. aureus bacteria with health and environmental protection results.
- Published
- 2021
19. Synthesis and characterization of porous ceramics from spodumene tailings and waste glass wool
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Lemougna, P. N. (Patrick N.), Yliniemi, J. (Juho), Adediran, A. (Adeolu), Luukkonen, T. (Tero), Tanskanen, P. (Pekka), Finnilä, M. (Mikko), Illikainen, M. (Mirja), Lemougna, P. N. (Patrick N.), Yliniemi, J. (Juho), Adediran, A. (Adeolu), Luukkonen, T. (Tero), Tanskanen, P. (Pekka), Finnilä, M. (Mikko), and Illikainen, M. (Mirja)
- Abstract
Glass wool waste remains a challenging waste fraction with relatively little utilization prospects. The present study investigated the development of porous ceramic materials from glass wool waste and spodumene tailings mainly made of quartz feldspar sand (QFS), with 0.05–0.5% silica carbide (SiC) as a pore-forming agent. The formulated compositions were sintered at 950 °C and analyzed in terms of mechanical properties, phase composition, and microstructure using X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray micro-computed tomography. The results showed that a synergetic effect of glass wool and SiC started to be significant from 15 wt% glass wool and 0.05 wt% SiC, the strength reducing and the porosity increasing with the increase of SiC. The porous ceramics were largely amorphous, with compressive strength ranging from 5 to 30 MPa while the water absorption and apparent density ranged from 2 to 10% and 0.7–1.2 g/cm³, respectively. The total porosity varied between 20 and 75%, and the wall thickness between 62 and 68 μm; besides, most of the prepared materials floated in water. These results are of interest for the repurposing of glass wool waste in the development of non-flammable lightweight materials for potential filtering or high-rise building applications.
- Published
- 2021
20. Mineralogy and glass content of Fe-rich fayalite slag size fractions and their effect on alkali activation and leaching of heavy metals
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Adediran, A. (Adeolu), Yliniemi, J. (Juho), Illikainen, M. (Mirja), Adediran, A. (Adeolu), Yliniemi, J. (Juho), and Illikainen, M. (Mirja)
- Abstract
Fayalite slag (FS) is an Fe-rich nonferrous metallurgy (CaO-MgO-) FeOx-SiO₂ slag originating from nickel or copper manufacturing processes, which currently is disposed to landfills or used in low-value applications. This study investigates the mineralogy and glass content of certain sized fractions of FS and how it influences the reactivity, mechanical, and microstructural properties of the alkali-activated materials produced. Water-quenched granular FS was sieved into two size fractions: namely, a fine fraction (FF) with a particle size range of 0–0.5 mm and a coarse fraction (CF) with a particle size range of 1.5–2 mm. It was then milled to a similar median particle size of 10 μm to be used as a binder precursor. The reaction kinetics of each fraction was determined via thermal analysis microcalorimeter, and the microstructural evolution and chemical composition of the binder were studied using a scanning electron microscope coupled with an energy dispersive X-ray spectroscopy. The environmental leaching behavior of both fractions before and after alkali activation was assessed according to the EN 12457–2 standard. The results showed that both fractions consisted of fayalite, magnetite crystalline phases, and MgO-SiO₂-FeOx (-CaO-Al₂O₃) glass phase. However, FF had a higher glass content (63 wt.%) in comparison to CF (39 wt.%), and, consequently, FF was more reactive under alkali activation, as evidenced by faster reaction kinetics, faster strength development, and improved microstructural properties. Alkali-activated samples had differences in the chemical compositions of their binder gels at early stages, though later, their binders became increasingly homogenous and consisted of an Na-K-Fe-Si gel with Mg, Ca, and Al as minor constituents in both samples. Additionally, the leaching behavior of potentially toxic metals and substances from precursors and alkali-activated samples prepared was below the limits set for paved structures as specified by Finnish
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- 2021
21. Effect of organic resin in glass wool waste and curing temperature on the synthesis and properties of alkali-activated pastes
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Lemougna, P. N. (Patrick N.), Adediran, A. (Adeolu), Yliniemi, J. (Juho), Luukkonen, T. (Tero), Illikainen, M. (Mirja), Lemougna, P. N. (Patrick N.), Adediran, A. (Adeolu), Yliniemi, J. (Juho), Luukkonen, T. (Tero), and Illikainen, M. (Mirja)
- Abstract
This study investigated the effect of organic resin contained in glass wool on synthesis of alkali-activated binders. The study was performed on glass wool containing sugar or phenolic resin, comparing it with glass wool that did not contain resin, as a reference. The results showed that the organic resin could be qualitatively identified using Fourier-transform infrared spectroscopy (FTIR) and thermo gravimetry-mass spectrometer (TG-MS), with gradual decomposition occurring between 200°C and 550°C. The presence of organic resin reduced the milling efficiency of glass wool, modified the rheology by increasing the liquid demand, and slowed the strength development at room temperature. However, interestingly, the effect of the resin on the strength of the paste was less obvious at an age of 28 days. Curing for 24 h at 40°C was beneficial for one-day strength development, in comparison to 20°C and 60°C, independent of the presence of the resin. All the cured paste samples, with and without resin, achieved a compressive strength of more than 40 MPa at 28 days, satisfying the requirement for many structural applications. Nevertheless, water immersion affected the materials’ strength, suggesting their suitability for dry environments or the need for suitable co-binders to increase their durability and water resistance.
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- 2021
22. Production of ceramic construction materials as an environmental management solution for sulfidic mine tailings
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Paiva, H. (H.), Simões, F. (F.), Maljaee, H. (H.), Yliniemi, J. (J.), Illikainen, M. (M.), Ferreira, V. M. (V. M.), Paiva, H. (H.), Simões, F. (F.), Maljaee, H. (H.), Yliniemi, J. (J.), Illikainen, M. (M.), and Ferreira, V. M. (V. M.)
- Abstract
Mine tailings (MT) waste valorization in construction materials can be one possible solution because they may allow an alternative for some applications as an important contribution for a more circular economy. The aim of this work was to study the feasibility of using a sulfidic mine tailing in the production of building materials such as ceramic roof tiles. The introduction of 5, 10 and 20% MT in ceramic roof tiles promoted an improvement on the final properties of these materials. The use of 20%MT has decreased the firing temperature from 1150º to 1050 ºC, hence promoting energy savings and lower costs. Properties as density and water absorption were improved. Firing shrinkage, many times responsible for cracking, also decrease with the use of MT and, in this way, improve the production rate. The 20% MT ceramic formulation achieved the highest value of strength with lowest firing temperature. For the effects of sulphates‘ emission (SO₂ and SO₃ gases) upon firing, a solution was proposed involving their reaction with water and, through condensation, providing afterwards sulphuric acid as a process by-product. The use of high sulphide MT in ceramic roof tiles processing could be viewed as a potential safe waste management solution for these particular mine tailings.
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- 2021
23. Influence of activator type on reaction kinetics, setting time, and compressive strength of alkali-activated mineral wools
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Yliniemi, J. (J.), Walkley, B. (B.), Provis, J. L. (J. L.), Kinnunen, P. (P.), Illikainen, M. (M.), Yliniemi, J. (J.), Walkley, B. (B.), Provis, J. L. (J. L.), Kinnunen, P. (P.), and Illikainen, M. (M.)
- Abstract
Alkali activation is a promising utilisation route for mineral wool wastes, due to suitable chemical composition, high reactivity, and surface area. One key factor in the development of alkali-activated binders is the selection of the suitable alkali activator. Here, the effect of sodium hydroxide, sodium silicate, sodium aluminate, and sodium carbonate solution on the alkali-activation kinetics of two main types of mineral wools, stone wool and glass wool, is investigated. Setting time and compressive strength development results are presented, which are explained and discussed in the context of isothermal calorimeter data obtained at temperature of 40 °C. Sodium hydroxide and sodium silicate solutions provided fast reaction with both mineral wools, evidenced by high heat release, high early strength, and fast setting. The reaction with sodium aluminate solution took several days to initiate, but it produced high compressive strength after 28 days of curing with both mineral wools. Glass wool reacted and hardened rapidly with sodium carbonate solution, but stone wool reacted slowly with sodium carbonate and exhibited a low extent of reaction, likely due to lower extent of reaction of stone wool under less alkaline conditions. These results show that mineral wool alkali activation kinetics and binder gel formation are controlled by the activator type and highlight the importance of choosing the most appropriate activator for each desired application.
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- 2021
24. Influence of sodium silicate powder silica modulus for mechanical and chemical properties of dry-mix alkali-activated slag mortar
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Luukkonen, T. (Tero), Sreenivasan, H. (Harisankar), Abdollahnejad, Z. (Zahra), Yliniemi, J. (Juho), Kantola, A. (Anu), Telkki, V.-V. (Ville-Veikko), Kinnunen, P. (Päivö), and Illikainen, M. (Mirja)
- Subjects
Blast furnace slag ,Dry-mix mortar ,Sodium silicate ,Silica modulus ,Geopolymer - Abstract
Sodium silicate powders with different SiO₂/Na₂O (silica modulus) were characterized by solubility rate, pH, and chemical structure (by ²⁹Si MAS-NMR) and compared in the preparation of one-part (or dry-mix) alkali-activated blast furnace slag mortar. The low SiO₂/Na₂O indicated the beneficial presence of less-polymerized silica (Q¹ and Q² Si environments) and thus faster dissolution. Consequently, using sodium silicates with SiO₂/Na₂O of 0.9, 2.1, and 3.4 resulted 28 d compressive strengths of 103, 80, and 2 MPa, respectively, with increasing setting time and decreasing heat release in isothermal calorimetry. Adjustment of activator SiO₂/Na₂O from 2.1 or 3.4 to 0.9 by adding NaOH powder resulted increased or decreased mechanical properties of mortar, respectively, depending on the initial silica modulus. These properties were not, however, similar to those obtained with sodium silicate having SiO₂/Na₂O of 0.9 originally. Depending on the case, the added NaOH can be consumed for dissolving sodium silicate activator, slag, or the forming (C,N)-(A)-S-H gel.
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- 2020
25. Utilisation of glass wool waste and mine tailings in high performance building ceramics
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Lemougna, P. N. (Patrick N.), Yliniemi, J. (Juho), Nguyen, H. (Hoang), Adesanya, E. (Elijah), Tanskanen, P. (Pekka), Kinnunen, P. (Päivö), Röning, J. (Juha), Illikainen, M. (Mirja), Lemougna, P. N. (Patrick N.), Yliniemi, J. (Juho), Nguyen, H. (Hoang), Adesanya, E. (Elijah), Tanskanen, P. (Pekka), Kinnunen, P. (Päivö), Röning, J. (Juha), and Illikainen, M. (Mirja)
- Abstract
The generation of glass wool waste and mine tailings has raised increasing concerns. This paper deals with the reuse of glass wool waste and lithium mine tailings from spodumene ore (quartz feldspar sand; QFS) in the development of building ceramic materials. The effect of glass wool particle size and sintering temperatures (750, 850 and 950 °C) were investigated. Phase composition and sintering reactions were studied using several techniques including X-ray diffraction with Rietveld refinement, differential scanning calorimetry, scanning electron microscopy, density, water absorption and mechanical tests. The results showed that glass wool acted as fluxing agent, with melting reactions observed from about 700 °C. Grinding glass wool improved its reactivity, enhancing densification and strength development at lower temperatures. The properties of the prepared building ceramics satisfied the requirement of building materials according to ASTM C62, achieving high performance values of 90 MPa and 25 MPa for compressive and flexural strength respectively. These results are of interest for the reuse of glass wool waste, QFS and similar waste streams in building ceramics.
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- 2020
26. Recycling glass wool as a fluxing agent in the production of clay- and waste-based ceramics
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Adediran, A. (Adeolu), Lemougna, P. N. (Patrick N.), Yliniemi, J. (Juho), Tanskanen, P. (Pekka), Kinnunen, P. (Paivo), Roning, J. (Juha), Illikainen, M. (Mirja), Adediran, A. (Adeolu), Lemougna, P. N. (Patrick N.), Yliniemi, J. (Juho), Tanskanen, P. (Pekka), Kinnunen, P. (Paivo), Roning, J. (Juha), and Illikainen, M. (Mirja)
- Abstract
Concerns about the management of glass wool waste, approximately 800,000 tons of which are generated annually in Europe, are increasing. To test the feasibility of incorporating this waste into ceramic materials, this study examined the reuse of glass wool as a fluxing agent in the production of clay- and waste-based building ceramics. Commercial kaolin clay and two industrial residues, namely quartz-feldspar sand (QFS) and copper slag (CS), were selected as the precursors. Six compositions were prepared, three samples containing glass wool and three counterparts without glass wool, and then sintered at 750, 850, and 950 °C. The materials and prepared ceramics were characterized by employing x-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive x-ray spectroscopy (EDS), differential scanning calorimetry (DSC), water absorption, apparent density, and compressive and flexural strength tests. Interestingly, the results indicated that incorporating 10 wt% of glass wool into the QFS, CS, and kaolin mixtures created ceramics with better physical, mechanical, and microstructural properties. This was ascribed to the glass wool melting reactions observed from approximately 700 °C. The QFS samples with glass wool and sintered at 950 °C achieved compressive strength values as high as 117 MPa and water absorption percentages as low as 2%. However, the fluxing effect of glass wool was less significant in the CS- and kaolin-based ceramics, likely due to differences in their chemical composition, mineralogy, and particle-size distribution. The results of this study emphasize the reuse potential of glass wool and other waste streams in building ceramics and could contribute to improving the management of glass wool waste in line with social sustainability objectives.
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- 2020
27. Opportunities to improve sustainability of alkali-activated materials:a review of side-stream based activators
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Adesanya, E. (Elijah), Perumal, P. (Priyadharshini), Luukkonen, T. (Tero), Yliniemi, J. (Juho), Ohenoja, K. (Katja), Kinnunen, P. (Paivo), Illikainen, M. (Mirja), Adesanya, E. (Elijah), Perumal, P. (Priyadharshini), Luukkonen, T. (Tero), Yliniemi, J. (Juho), Ohenoja, K. (Katja), Kinnunen, P. (Paivo), and Illikainen, M. (Mirja)
- Abstract
Alkali-activated materials (AAMs) are alternative binders that can be used instead of Portland cement in construction. One of the main drivers in their utilization is that AAMs can be designed to have lower CO2 emissions using industrial residues. The main component of AAMs is aluminosilicate precursor, which is frequently waste based. However, the sustainable profile and cost-efficiency of AAMs are greatly affected by the selection of the alkali activator. Commonly used activators include bulk chemicals, such as sodium hydroxide or silicates, which have a relatively high carbon footprint and cost that can inhibit AAM applicability for large-scale construction applications. Consequently, several locally available, but underutilized, agricultural and industrial by-products or wastes have been investigated as alternative alkali activators. Globally, millions of tons of these residues are produced annually, and currently, they are mostly landfilled. Utilization of these residues as alternative alkali activators not only solves the residues-management issue, but also has noteworthy economic and environmental benefits. Utilization and properties of these waste-based activators in AAMs are comprehensively reviewed in this manuscript. Various studies showed the formation of alkali silicates from amorphous silica residues, alkali hydroxides, carbonates, and aluminates sourced from biomass and industrial residues. The resulting binder exhibited similar reactivity to commercial activators and considerable binder strength. However, the durability, shrinkage, and workability properties were not investigated in most of the reviewed studies.
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- 2020
28. Thermal stability of one-part metakaolin geopolymer composites containing high volume of spodumene tailings and glass wool
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Lemougna, P. N. (Patrick N.), Adediran, A. (Adeolu), Yliniemi, J. (Juho), Ismailov, A. (Arnold), Levanen, E. (Erkki), Tanskanen, P. (Pekka), Kinnunen, P. (Paivo), Röning, J. (Juha), Illikainen, M. (Mirja), Lemougna, P. N. (Patrick N.), Adediran, A. (Adeolu), Yliniemi, J. (Juho), Ismailov, A. (Arnold), Levanen, E. (Erkki), Tanskanen, P. (Pekka), Kinnunen, P. (Paivo), Röning, J. (Juha), and Illikainen, M. (Mirja)
- Abstract
This paper deals with the synthesis and thermal stability of one-part metakaolin geopolymer composites containing high volume of spodumene tailings (Quartz Feldspar Sand; QFS) and glass wool (GW). One of the objectives of the study was to prepare materials encompassing a maximum amount of waste streams with some potential thermal stability. Several compositions were prepared with sodium metasilicate anhydrous (Na2SiO3) wt.% of 0.5, 2.5, 5, 10 and 12,5. The one-part metakaolin geopolymer composites were cured at 60 °C for 24 h and the mechanical properties were assessed at 7 days and after post-heat treatment at 500, 750, 1000, 1100 or 1200 °C. X-ray diffraction, dilatometry, scanning electron microscopy and thermogravimetry analyses were used to study the stability of the prepared geopolymer composites until 1100–1200 °C. The results showed that more than 20 MPa compressive strength could be achieved with metakaolin geopolymer composites containing only 20 wt% of metakaolin. Metakaolin-GW geopolymer composites were stable up to 500 °C. Meanwhile, their counterparts containing QFS were stable up to 1100–1200 °C; samples prepared with higher dosage of sodium (Na2SiO3 > 5 wt%) retained more than 50% of their initial strength after thermal treatment at 1100 °C. Interestingly, for dosages of Na2SiO3 ≤ 5 wt%, more than 300% increase of strength was observed after thermal treatment at 1100–1200 °C. The use of QFS limited the thermal shrinkage at mild temperatures (<1000 °C), but favoured densification and strength development at 1100–1200 °C.
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- 2020
29. Sustainable batching water options for one-part alkali-activated slag mortar:sea water and reverse osmosis reject water
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Luukkonen, T. (Tero), Yliniemi, J. (Juho), Kinnunen, P. (Päivö), Illikainen, M. (Mirja), Luukkonen, T. (Tero), Yliniemi, J. (Juho), Kinnunen, P. (Päivö), and Illikainen, M. (Mirja)
- Abstract
Concrete production is globally a major water consumer, and in general, drinking-quality water is mixed in the binder. In the present study, simulated sea water and reverse osmosis reject water were used as batching water for one-part (dry-mix) alkali-activated blast furnace slag mortar. Alkali-activated materials are low-CO₂ alternative binders gaining world-wide acceptance in construction. However, their production requires approximately similar amount of water as regular Portland cement concrete. The results of the present study revealed that the use of saline water did not hinder strength development, increased setting time, and did not affect workability. The salts incorporated in the binder decreased the total porosity of mortar, but they did not form separate phases detectable with X-ray diffraction or scanning electron microscopy. Leaching tests for monolithic materials revealed only minimal leaching. Furthermore, results for crushed mortars (by a standard two-stage leaching test) were within the limits of non-hazardous waste. Thus, the results indicated that high-salinity waters can be used safely in one-part alkali-activated slag to prepare high-strength mortars. Moreover, alkali-activation technology could be used as a novel stabilization/solidification method for reverse osmosis reject waters, which frequently pose disposal problems.
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- 2020
30. Reuse of copper slag in high-strength building ceramics containing spodumene tailings as fluxing agent
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Lemougna, P. N. (Patrick N.), Yliniemi, J. (Juho), Adesanya, E. (Elijah), Tanskanen, P. (Pekka), Kinnunen, P. (Päivö), Röning, J. (Juha), Illikainen, M. (Mirja), Lemougna, P. N. (Patrick N.), Yliniemi, J. (Juho), Adesanya, E. (Elijah), Tanskanen, P. (Pekka), Kinnunen, P. (Päivö), Röning, J. (Juha), and Illikainen, M. (Mirja)
- Abstract
The recycling of industrial side streams is of interest for a sustainable use of resources and from an environmental perspective. This paper deals with the reuse of copper slag and spodumene tailings in the development of ceramic materials for potential application in construction. Copper slag included fayalite and magnetite as crystalline phases while spodumene tailings (quartz-felspar sand, QFS) mainly consisted of albite, quartz and microcline. Kaolin (10 wt%) was added as green strength increasing agent in some compositions and the prepared formulations were sintered between 950 and 1150 °C at 50 °C intervals. The phase composition was studied by scanning electron microscopy and X-ray diffraction using Rietveld refinement. Tests such as compressive and flexural strength, water absorption, apparent density and freeze thaw cycles were used to assess the material performances. The results showed that densification and strength development were mainly due to partial melting of QFS particles at 1050–1100 °C, leading to water absorption in the range 0.5–7 %. At 1100 °C, a high-performance compressive strength of 140 MPa was achieved with the formulation made fully of recycled materials (50 wt% copper slag and 50 wt% QFS) suggesting its suitability for high strength demanding materials such as load bearing bricks; values of ultrasonic pulse velocity and compressive strength of these ceramics remained stable after 200 freeze thaw cycles, demonstrating their potential suitability as construction materials in severe weathering environments. Additionally, the leaching test proved a good encapsulation of heavy metals in these ceramics. These results are of interest for waste management and efficient use of resources.
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- 2020
31. Utilization of fly ashes from fluidized bed combustion::a review
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Ohenoja, K. (Katja), Pesonen, J. (Janne), Yliniemi, J. (Juho), Illikainen, M. (Mirja), Ohenoja, K. (Katja), Pesonen, J. (Janne), Yliniemi, J. (Juho), and Illikainen, M. (Mirja)
- Abstract
Traditionally fly ash is thought to be glassy, spherical particle originating from pulverized coal combustion (PCC) at temperature up to 1700 °C. However, nowadays fluidized bed combustion (FBC) technology is spreading quickly around the world as it is an efficient and environmentally friendly method. FBC is also able to utilize mixtures of low-grade solid fuels (e.g., coal, lignite, biomass, and waste) that have fluctuating quality, composition, and moisture contents. However, this leads to a high variation in the produced fly ash quality, unlike PCC fly ash, and hence challenges when attempting to utilize this fly ash. In this study, the utilization of fluidized bed combustion fly ash (FBCFA) was reviewed using the Scopus database. The most promising utilization target for FBCFA from biomass combustion is as a fertilizer and soil amendment. In construction, the FBCFA from various fuels is utilized as cement replacement material, in non-cement binders, as lightweight aggregates and cast-concrete products. Other types of construction applications include mine backfilling material, soil stabilizer, and road construction material. There are also other promising applications for FBCFA utilization, such as catalysts support material and utilization in waste stabilization.
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- 2020
32. Ag- or Cu-modified geopolymer filters for water treatment manufactured by 3D printing, direct foaming, or granulation
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Luukkonen, T. (Tero), Yliniemi, J. (Juho), Sreenivasan, H. (Harisankar), Ohenoja, K. (Katja), Finnilä, M. (Mikko), Franchin, G. (Giorgia), Colombo, P. (Paolo), Luukkonen, T. (Tero), Yliniemi, J. (Juho), Sreenivasan, H. (Harisankar), Ohenoja, K. (Katja), Finnilä, M. (Mikko), Franchin, G. (Giorgia), and Colombo, P. (Paolo)
- Abstract
In this work, we compared the main characteristics of highly porous geopolymer components for water treatment applications manufactured by 3D printing, direct foaming, or granulation. Furthermore, different approaches to impregnate the materials with Ag or Cu were evaluated to obtain filters with disinfecting or catalytic properties. The results revealed that all of the investigated manufacturing methods enabled the fabrication of components that possessed mesoporosity, suitable mechanical strength, and water permeability, even though their morphologies were completely different. Total porosity and compressive strength values were 28 vol% and 16 MPa for 3D-printed, 70–79 vol% and 1 MPa for direct-foamed, and 27 vol% and 10 MPa for granule samples. Both the filter preparation and the metal impregnation method affected the amount, oxidation state, and stability of Ag and Cu in the filters. However, it was possible to prepare filters with low metal leaching between a pH of 3–7, so that the released Ag and Cu concentrations were within drinking water standards.
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- 2020
33. Nanostructural evolution of alkali-activated mineral wools
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Yliniemi, J. (J.), Walkley, B. (B.), Provis, J. L. (J. L.), Kinnunen, P. (P.), Illikainen, M. (M.), Yliniemi, J. (J.), Walkley, B. (B.), Provis, J. L. (J. L.), Kinnunen, P. (P.), and Illikainen, M. (M.)
- Abstract
Mineral wools are the most widely used building insulation material worldwide. Annually, 2.5 million tonnes of mineral wool waste are generated in the EU alone, and this is a largely unutilised material that is landfilled or incinerated. However, mineral wool wastes are promising precursors for production of alkali-activated cementitious binders due to their favourable chemical and mineralogical composition and high surface area. Alkali-activation is therefore a valuable route for valorisation of large quantities of mineral wool waste. This study resolves the phase assemblage and nanostructure of reaction products formed upon alkali activation of stone wool and glass wool by sodium hydroxide and sodium silicate solutions with X-ray diffraction, electron microscopy and solid state nuclear magnetic resonance spectroscopy experiments probing ²⁷Al and ²⁹Si. The stone wool-based alkali-activated binder comprises an amorphous sodium- and aluminium-substituted calcium silicate hydrate (C-(N-)A-S-H) gel, an amorphous sodium aluminosilicate hydrate (N-A-S-H) gel and small amounts of the layered double hydroxide phase quintinite and zeolite F. The glass wool-based alkali-activated binder comprises an amorphous Ca- and Al-substituted sodium silicate (N-(C-)(A-)S-H) gel. Gel chemical composition and reaction kinetics of alkali-activated mineral wools are shown to be dependent on the activating solution chemistry, with reaction rate and extent promoted by inclusion of a source of soluble Si in the reaction mixture. This work provides the most advanced description of the chemistry and structure of alkali-activated mineral wools to date, yielding new insight that is essential in developing valorisation pathways for mineral wools by alkali activation and providing significant impetus for development of sustainable construction materials.
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- 2020
34. Fiber reinforced alkali-activated stone wool composites fabricated by hot-pressing technique
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Nguyen, H. (Hoang), Kaas, A. (Alexandra), Kinnunen, P. (Paivo), Carvelli, V. (Valter), Monticelli, C. (Carol), Yliniemi, J. (Juho), Illikainen, M. (Mirja), Nguyen, H. (Hoang), Kaas, A. (Alexandra), Kinnunen, P. (Paivo), Carvelli, V. (Valter), Monticelli, C. (Carol), Yliniemi, J. (Juho), and Illikainen, M. (Mirja)
- Abstract
Cementitious composite that has short molding time and high mechanical performance is favorable in pre-cast concrete industry. In this context, this study reports the use of hot-pressing technique to fabricate PVA fiber reinforced composites using alkali-activated stone wool (a waste from building insulation). Eight different mixtures were developed by varying the pressing time and temperature in comparison to the conventional oven-cured alkali-activated material. The mechanical performance of all compositions was evaluated under bending and compressive loadings. Life cycle assessment was used to investigate the greenhouse gas emission and embodied energy of the developed composites. The results reveal that PVA fibers greatly enhanced the mechanical performance of all reinforced mixtures with deflection hardening behavior and improvement in compressive strength. The hot-pressing technique lowered CO₂ emission and saved energy. Finally, a multi-criteria ranking method suggests hot-pressed PVA fiber reinforced cementitious composite, manufactured at 120 °C for 2 h, is the best composition attaining balance among energy spent, mechanical properties, and CO₂ footprint.
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- 2020
35. Special Contribution: An Overview of Recent Seismic Refraction Experiments in Central Europe
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Guterch, A., Grad, M., Špičák, A., Brückl, E., Hegedüs, E., Keller, G.R., Thybo, H., Aric, K., Acevedo, S., Asudeh, I., Behm, M., Belinsky, A. A., Bodoky, T., Brinkmann, R., Brož, M., Brückl, E., Chwatal, W., Clowes, R., Czuba, W., Fancsik, T., Forkmann, B., Fort, M., Gaczyński, E., Gebrande, H., Geissler, H., Gosar, A., Grad, M., Grassi, H., Greschke, R., Guterch, A., Hajnal, Z., Harder, S., Hegedüs, E., Hemmann, A., Hock, S., Hoeck, V., Hrubcová, P., Janik, T., Jentzsch, G., Joergensen, P., Kaip, G., Keller, G.R., Komminaho, K., Korn, M., Karousová, O., Kostiuchenko, S.L., Kohlbeck, F., Kracke, D., Majdański, M., Malinowski, M., Miller, K.C., Morozov, A.F., Rumpfhuber, E.-M., Schmid, Ch., Snelson, C., Špičák, A., Środa, P., Sumanovac, F., Takacs, E., Thybo, H., Tiira, T., Tomek, Č., Vozár, J., Weber, F., Wilde-Piórko, M., Yliniemi, J., and Żelaźniewicz, A.
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- 2003
- Full Text
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36. Special Contribution: ALP 2002 Seismic Experiment
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Brückl, E., Bodoky, T., Hegedüs, E., Hrubcová, P., Gosar, A., Grad, M., Guterch, A., Hajnal, Z., Keller, G.R., Špičák, A., Sumanovac, F., Thybo, H., Weber, F., Aric, K., Behm, M., Bleibinhaus, F., Brož, M., Brückl, E., Chwatal, W., Gebrande, H., Grad, M., Grassl, H., Gosar, A., Guterch, A., Hajnal, Z., Harder, S.H., Hegedüs, E., Hock, S., Höck, V., Hrubcová, P., Joergensen, P., Keller, G.R., Kohlbeck, F., Miller, K.C., Rumpfhuber, E.-M., Schmid, Ch., Schmöller, R., Snelson, C.M., Špičák, A., Sumanovac, F., Thybo, H., Tiira, T., Tomek, Č., Ullrich, Ch., Wilde-Piórko, M., and Yliniemi, J.
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- 2003
- Full Text
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37. Special Contribution: CELEBRATION 2000 Seismic Experiment
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Guterch, A., Grad, M., Keller, G.R., Posgay, K., Vozár, J., Špičák, A., Brückl, E., Hajnal, Z., Thybo, H., Selvi, O., Acevedo, S., Aric, K., Asudeh, I., Belinsky, A.A., Bodoky, T., Brückl, E., Chwatal, W., Clowes, R., Czuba, W., Fancsik, T., Gaczyński, E., Grad, M., Guterch, A., Hajnal, Z., Harder, S., Hegedüs, E., Hrubcová, P., Janik, T., Jentzsch, G., Joergensen, P., Kaip, G., Keller, G.R., Komminaho, K., Kostiuchenko, S.L., Kracke, D., Kohlbeck, F., Miller, K.C., Morozov, A.F., Posgay, K., Selvi, O., Špičák, A., Snelson, C., Środa, P., Takács, E., Thybo, H., Tiira, T., Vozár, J., Wilde-Piórko, M., and Yliniemi, J.
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- 2003
- Full Text
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38. Special Contribution: SUDETES 2003 Seismic Experiment
- Author
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Grad, M., Špičák, A., Keller, G.R., Guterch, A., Brož, M., Hegedüs, E., Behm, M., Bodoky, T., Brinkmann, R., Brož, M., Brückl, E., Czuba, W., Fancsik, T., Forkmann, B., Fort, M., Gaczynski, E., Geissler, W.H., Grad, M., Greschke, R., Guterch, A., Harder, S., Hegedüs, E., Hemmann, A., Hrubcová, P., Janik, T., Jentzsch, G., Kaip, G., Keller, G.R., Komminaho, K., Korn, M., Karousová, O., Majdański, M., Málek, J., Malinowski, M., Miller, K.C., Rumpfhuber, E.-M., Spicak, A., Środa, P., Takács, E., Tiira, T., Vozár, J., Wilde-Piórko, M., Yliniemi, J., and Żelaźniewicz, A.
- Published
- 2003
- Full Text
- View/download PDF
39. Influence of activator type on reaction kinetics, setting time, and compressive strength of alkali-activated mineral wools
- Author
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Yliniemi, J., primary, Walkley, B., additional, Provis, J. L., additional, Kinnunen, P., additional, and Illikainen, M., additional
- Published
- 2020
- Full Text
- View/download PDF
40. Nanostructural evolution of alkali-activated mineral wools
- Author
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Yliniemi, J., primary, Walkley, B., additional, Provis, J.L., additional, Kinnunen, P., additional, and Illikainen, M., additional
- Published
- 2020
- Full Text
- View/download PDF
41. Spodumene tailings for porcelain and structural materials:effect of temperature (1050–1200 °C) on the sintering and properties
- Author
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Lemougna, P. N. (Patrick N.), Yliniemi, J. (Juho), Ismailov, A. (Arnold), Levanen, E. (Erkki), Tanskanen, P. (Pekka), Kinnunen, P. (Paivo), Roning, J. (Juha), and Illikainen, M. (Mirja)
- Subjects
Mine tailings ,Structural applications ,Porcelain ,Feldspars ,Quartz - Abstract
The use of industrial by-products as substitute to conventional natural resources in ceramic production is of interest from an environment preservation and solid wastes management. This paper deals with the recycling of tailings from spodumene concentration during lithium production (Quartz Feldspar Sand; QFS), for the production of porcelain and structural materials. The QFS obtained from spodumene processing consisted mainly of quartz, albite, microcline with traces of muscovite. Mixtures of QFS and standard porcelain ingredients were sintered at 1050–1200 °C at 50 °C intervals and their properties were compared with a conventional porcelain composition prepared under the same conditions. Phase composition was assessed by XRD analysis using Rietveld refinement. Tests such as water absorption, apparent density, sintering shrinkage, compressive and flexural strength were used for physical comparison. The results showed that higher densification was achieved at 1200 °C, with a drastic reduction of water absorption below 1%. A compressive strength of 40 MPa was obtained at 1050 °C in the composition made of 50 wt% QFS and 50 wt% kaolin, increasing to 85 MPa at 1100 °C. The strength increase was attributed to better glassy phase formation and mullite growth. The QFS was found to contain no hazardous elements and showed promising sintering results, indicating its high suitability to substitute conventional resources in the production of ceramic materials.
- Published
- 2019
42. Application of alkali-activated materials for water and wastewater treatment:a review
- Author
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Luukkonen, T. (Tero), Heponiemi, A. (Anne), Runtti, H. (Hanna), Pesonen, J. (Janne), Yliniemi, J. (Juho), and Lassi, U. (Ulla)
- Subjects
Alkali-activation ,Adsorption ,Wastewater treatment ,Solidification/stabilization ,Geopolymer ,Catalysis - Abstract
Alkali-activation (or geopolymer) technology has gained a great deal of interest for its potential applications in water and wastewater treatment during the last decade. Alkali-activated materials can be prepared via a relatively simple and low-energy process, most commonly by treating aluminosilicate precursors with concentrated alkali hydroxide and/or silicate solutions at (near) ambient conditions. The resulting materials are, in general, amorphous, have good physical and chemical stability, ion-exchange properties, and a porous structure. Several of the precursors are industrial by-products or other readily available low-cost materials, which further enhances the environmental and economic feasibility. The application areas of alkali-activated materials in water and wastewater treatment are adsorbents/ion-exchangers, photocatalysts, high-pressure membranes, filter media, anti-microbial materials, pH buffers, carrier media in bioreactors, and solidification/stabilization of water treatment residues. The purpose of this review is to present a comprehensive evaluation of the rapidly growing prospects of alkali-activation technology in water and wastewater treatment.
- Published
- 2019
43. Recycling lithium mine tailings in the production of low temperature (700–900 °C) ceramics:effect of ladle slag and sodium compounds on the processing and final properties
- Author
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Lemougna, P. N. (Patrick N.), Yliniemi, J. (Juho), Ismailov, A. (Arnold), Levanen, E. (Erkki), Tanskanen, P. (Pekka), Kinnunen, P. (Paivo), Roning, J. (Juha), and Illikainen, M. (Mirja)
- Subjects
Ladle slag ,Fluxing agent ,Ceramic ,Lithium mine tailings ,Building applications ,Sodium compounds - Abstract
This paper deals with the valorization of quartz and felspar rich lithium mine tailings (QFS) in the development of construction materials. Ladle slag was used as green strength increasing agent. Sodium hydroxide and carbonate were used as fluxing agents to allow sintering at 700–900 °C. Of these, sodium hydroxide was found to be the more efficient. The sintered ceramics were characterized by X-ray diffraction, scanning electron microscopy, compressive test, water absorption, apparent density and dilatometry; the results were found to comply with ASTM C62–99 specifications for building brick, and interesting for a sustainable use of resources.
- Published
- 2019
44. Fayalite slag as binder and aggregate in alkali-activated materials:interfacial transition zone study
- Author
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Adediran, A. (Adeolu), Yliniemi, J. (Juho), Illikainen, M. (Mirja), Adediran, A. (Adeolu), Yliniemi, J. (Juho), and Illikainen, M. (Mirja)
- Published
- 2019
45. Mechanical transformation of phyllite mineralogy toward its use as alkali-activated binder precursor
- Author
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Adesanya, E. (Elijah), Ohenoja, K. (Katja), Yliniemi, J. (Juho), Illikainen, M. (Mirja), Adesanya, E. (Elijah), Ohenoja, K. (Katja), Yliniemi, J. (Juho), and Illikainen, M. (Mirja)
- Abstract
The mechanical activation of phyllite for use as an alkali-activated material was studied. Prolonged milling of phyllite resulted in reduced particle size and a structural reorganization of the material, leading to incremental increases in amorphous content, which further resulted in the improved reactivity of phyllite in an alkaline environment. Quantitative X-ray diffraction results showed that the phyllite consisted of quartz, muscovite, chamosite, albite, and X-ray amorphous phases. Among the crystalline phases, muscovite and chamosite underwent the most structural reorganization, leading to a more disordered structure due to prolonged and intensive milling. The structural reorganization was also established through Fourier-transform infrared spectroscopy. Dissolution tests in 6 M NaOH showed incremental increases in leached Al and Si elements with increased milling time. After geopolymerization of mechanically activated phyllite, calorimetric studies showed exothermic reactions, and a 28-day compressive strength of 25 MPa was achieved for paste samples cured at room temperature. This study ascertained the potential utilization of phyllite mineral waste in sustainable cement applications.
- Published
- 2019
46. Mineral wool waste-based geopolymers
- Author
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Yliniemi, J. (Juho), Luukkonen, T. (Tero), Kaiser, A. (Anne), Illikainen, M. (Mirja), Yliniemi, J. (Juho), Luukkonen, T. (Tero), Kaiser, A. (Anne), and Illikainen, M. (Mirja)
- Abstract
Mineral wools —a general term for stone wool and glass wool— are the most common building insulation materials in the world. The annual amount of mineral wool waste generated in Europe totaled 2.3 Mt in 2010 — including wastes from the mineral wool production and from the construction and demolition industry. Unfortunately, mineral wools are often considered unrecyclable due to their fibrous nature and low density. Thus, the utilisation of post-consumer mineral wool waste in different applications remains low. Mineral wools have a great potential as geopolymer precursors as they have suitable chemical and mineralogical compositions. As geopolymers can provide significant CO₂ emission reductions compared to traditional Portland cement concretes, using mineral wool waste as geopolymer precursor would be an attractive utilisation path. Here, we show that mineral wool waste can be geopolymerised to form sustainable cements with good mechanical properties. Geopolymerisation of mineral wool waste therefore offers an attractive route for waste valorisation and production of low-CO₂ cements.
- Published
- 2019
47. Alkali-activated soapstone waste - mechanical properties, durability, and economic prospects
- Author
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Luukkonen, T. (Tero), Abdollahnejad, Z. (Zahra), Yliniemi, J. (Juho), Mastali, M. (Mohammad), Kinnunen, P. (Päivö), Illikainen, M. (Mirja), Luukkonen, T. (Tero), Abdollahnejad, Z. (Zahra), Yliniemi, J. (Juho), Mastali, M. (Mohammad), Kinnunen, P. (Päivö), and Illikainen, M. (Mirja)
- Abstract
Soapstone is a soft, magnesium-rich mineral widely used in the production of carved objects and architectural elements, for instance. The processing of soapstone causes the formation of significant amounts of waste powder, which is largely landfilled at the moment. The aim of the present study is to evaluate the suitability of soapstone waste as the main binder for the alkali-activation process using sodium silicate and hydroxide solutions as activators. The results demonstrate that soapstone alone reacts to some extent (compressive strength of 13 MPa at 28 day age), but mechanical properties are improved significantly after replacing 20% of soapstone by metakaolin (compressive strength of 31 MPa at 28 d age). The obtained mechanical properties are closely similar to those of virgin soapstone. Durability properties of the developed alkali-activated binders were similar or better than typical Portland cement-based binders in terms of high temperature, acid, and freeze-thaw resistance, and sorptivity. The material costs alkali-activated soapstone mortar were estimated as approximately 70 €/t. Thus, the results enable utilizing currently underexploited soapstone waste in a sustainable and economically interesting way.
- Published
- 2019
48. Mine tailings geopolymers as a waste management solution for a more sustainable habitat
- Author
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Paiva, H. (Helena), Yliniemi, J. (Juho), Illikainen, M. (Mirja), Rocha, F. (Fernando), Ferreira, V. M. (Victor M.), Paiva, H. (Helena), Yliniemi, J. (Juho), Illikainen, M. (Mirja), Rocha, F. (Fernando), and Ferreira, V. M. (Victor M.)
- Abstract
The demand for low environmental impact of materials in our habitat is one of the current societal challenges. Along with other solutions of waste valorisation, alkali activation as geopolymers can be one possible solution of waste valorisation because they may allow, for instance, an alternative solution for cement-based materials in some applications and it is one contribution for circular economy. This work has focused on the development and processing of geopolymers that incorporates as a fine aggregate a high-sulfidic mining waste (mine tailing), a difficult waste to process. Rheology analysis was applied as an important step to understand not only the geopolymers behaviour but also its transition from the fresh to the hardened state. The effect of precursor binder type (metakaolin or blast furnace slag), of mine tailing content and also the effect of temperature and curing conditions of different formulations were studied in this solution. It was possible to conclude that although this particular mine tailing is not a geopolymer binder precursor, it may be incorporated as an alternative fine aggregate in construction products. Furthermore, rheology could be used to follow up the geopolymer alkali-activation process and even to setup proper curing conditions and components contents in order to optimize the final mechanical strength of this material as a waste management solution. The final properties of these geopolymers compositions were adequate and after 28 days of curing, these geopolymers exhibit significant chemical resistance under severe test conditions.
- Published
- 2019
49. One-part alkali-activated materials:a review
- Author
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Luukkonen, T. (Tero), Abdollahnejad, Z. (Zahra), Yliniemi, J. (Juho), Kinnunen, P. (Päivö), and Illikainen, M. (Mirja)
- Subjects
One-part geopolymer ,Blended cement ,Geopolymer ,Alkali-activated cement - Abstract
Alkali-activated materials (AAM) are recognized as potential alternatives to ordinary Portland cement (OPC) in order to limit CO₂ emissions as well as beneficiate several wastes into useful products. However, the alkali activation process involves concentrated aqueous alkali solutions, which are corrosive, viscous, and, as such, difficult to handle and not user friendly. Consequently, the development of so-called one-part or “just add water” AAM may have greater potential than the conventional two-part AAM, especially in cast-in-situ applications. One-part AAM involves a dry mix that consists of a solid aluminosilicate precursor, a solid alkali source, and possible admixtures to which water is added, similar to the preparation of OPC. The dry mix can be prepared at elevated temperatures to facilitate the reactivity of certain raw materials. This review discusses current studies of one-part AAMs in terms of raw materials, activators, additives, mechanical and physical properties, curing mechanisms, hydration products, and environmental impacts.
- Published
- 2018
50. Pulverization of fibrous mineral wool waste
- Author
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Yliniemi, J. (J.), Laitinen, O. (O.), Kinnunen, P. (P.), and Illikainen, M. (M.)
- Subjects
Man made vitreous fiber (MMVF) ,Mineral wool fiber ,Fiber conversion ,Comminution ,Milling - Abstract
The total annual volume of mineral wool waste in the 27 European Union countries is expected to increase to 2.5 million tons per year by 2020. Unfortunately, mineral wool wastes are often considered unrecyclable, because their physical characteristics make them difficult to process. In many cases, the problem is caused by the material’s fibrousness. However, no studies have considered comminution methods for mineral wools. The objective of the present study is to investigate how various comminution mechanisms affect mineral wools’ physical characteristics, including appearance, bulk density, and fiber length and width. The study’s results show that compression-based methods (vibratory disc mill and hydraulic press) completely break down mineral wools’ fibrousness, whereas methods based on high cutting speeds affect bulk density and fiber length only moderately. In addition, the present study identifies a rapid method that can be used in a novel way to analyze a large number of mineral wool fibers.
- Published
- 2018
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