Journal Article

FZJ-2020-03982

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Viscosity and crystal morphology data of anorthite bearing synthetic coal slag systems

Schupsky, J. P. (Corresponding author)FZJ* ; Saar, O. ; Wu, G.FZJ* ; Dohrn, M. ; Müller, M.FZJ*

2020
Elsevier New York, NY [u.a.]

This record in other databases:  

Please use a persistent id in citations: http://hdl.handle.net/2128/25888  doi:10.1016/j.fuel.2020.118663

Abstract: In this study, three synthetic SiO2-Al2O3-CaO-Fe2O3(-MgO) coal slag systems (ST-D-2, HKT, SOM-1) with varying basicity were investigated on their viscosity and the dominant crystallisation product: anorthite (CaAl2Si2O8). To predict crystallisation products, thermodynamic equilibrium calculations were executed using FactSage and the GTox database. Anorthite is predicted as a major crystallising phase in the slags. High temperature viscosimetry revealed non-Newtonian behaviour of the slags below 1275 °C. Additional viscosity measurements revealed viscosity deviations, based on crystallisation. Post-experimental analysis of the slags revealed the presence of elongated crystals with anorthite composition. Additional quenching experiments were performed and crystallisation results of the HKT slag were exemplarily shown in this study. Quenched samples were analysed by XRD and SEM-EDX to determine the crystallised phases and the crystal structure. Anorthite was identified as the dominant phase in the HKT slag but also in the ST-D-2 and SOM-1 slag system. As crystallisation strongly influences slag viscosity, a phase analysis of anorthite was conducted. The crystal morphology of anorthite displayed a common elongated characteristic and was generalised as a tetragonal prism with variations in its dimensions. Crystal size measurements ascertained constant small crystal sizes at temperatures below 1100 °C, and exhibited an increase of anorthite length with increasing temperatures above 1100 °C. Additionally, the aspect ratio was examined to ensure a complete three-dimensional characterisation of the anorthite phase. Crystal morphology data can be used in a future viscosity model as enhancing parameters to enable the calculation of viscosities for partly crystallised slags.

---

Contributing Institute(s):

1. Werkstoffstruktur und -eigenschaften (IEK-2)

Research Program(s):

1. 113 - Methods and Concepts for Material Development (POF3-113) (POF3-113)

Appears in the scientific report 2020

---

Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

---