RT Journal Article
T1 Factors affecting co-valorization of fayalitic and ferronickel slags for the production of alkali activated materials
A1 Komnitsas, Konstantinos
A1 Yurramendi, Lourdes
A1 Bartzas, Georgios
A1 Karmali, Vasiliki
A1 Petrakis, Evangelos
AB The first objective of this experimental study is the assessment of the alkali activation potential of two types of fayalitic slags, an as-received one (FS) and the one obtained after plasma treatment (FSP) of the initial FS, for the production of alkali activated materials (AAMs). Furthermore, the second objective is the elucidation of the co-valorization potential of FS and FSP slags when mixed with ferronickel (FeNi) slag (LS). The alkaline activating solution used was a mixture of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). The effect of various operating parameters, such as H2O/Na2O and SiO2/Na2O ratios present in the activating solution, curing temperature, curing period and ageing period on the compressive strength, density, water adsorption, porosity and toxicity of the produced AAMs was explored. The structural integrity of selected AAMs was investigated after firing specimens for 6 h at temperature up to 500 °C, immersion in distilled water and acidic solution or subjection to freeze-thaw cycles for a period of 7 or 30 days. The results of this study show that FS- and FSP-based AAMs acquire compressive strength of 44.8 MPa and 27.2 MPa, respectively. When FS and FSP were mixed with LS at 50:50%wt ratios the compressive strength of the produced specimens increased to 64.3 MPa and 45.8 MPa, respectively. Furthermore, selected AAMs produced after co-valorisation of slags retained sufficient compressive strength after firing at 500 °C, 45–68 MPa, and exhibited very low toxicity. These findings prove the alkali activation potential of fayalitic slags as well as their co-valorization with ferronickel slag for the production of AAMs, an approach which is in line with the principles of zero-waste and circular economy.
SN 0048-9697
YR 2020
FD 2020-06-15
LK https://hdl.handle.net/11556/4525
UL https://hdl.handle.net/11556/4525
LA eng
NO Komnitsas , K , Yurramendi , L , Bartzas , G , Karmali , V & Petrakis , E 2020 , ' Factors affecting co-valorization of fayalitic and ferronickel slags for the production of alkali activated materials ' , Science of the Total Environment , vol. 721 , 137753 . https://doi.org/10.1016/j.scitotenv.2020.137753
NO Publisher Copyright: © 2020 Elsevier B.V.
NO The authors would like to acknowledge the financial support of European Commission in the frame of Horizon 2020 project “Metal recovery from low-grade ores and wastes”, www.metgrowplus.eu , Grant Agreement n° 690088.
DS TECNALIA Publications
RD 30 jul 2024