Abstract
This paper presents studies on the utilization of aluminosilicate-based mining tailings as raw materials for mullite-based ceramics. Based on the 3:2 stoichiometric composition, mullite was synthesised by reactive sintering with a series of powder mixtures with alumina additions. X-ray diffractometry and scanning electron microscopy analyses revealed that, at the specific mineralogical composition, mullite structure formed surrounded by an amorphous glass phase in reaction-sintered powder mixtures. Results demonstrated that the chemical and mineralogical composition of mining tailings do have an effect on mullite formation possibilities and, only with the particular mineralogical composition, the mullite formation is possible regardless of the correct Al:Si ratio in tailings. Physical and mechanical properties of the formed ceramics were defined, showing comparable values to 3:2 mullite reference. Mullite structure formation enables a better thermal resistance up to above 1450 °C of the formed tailings-based ceramics compared to other aluminosilicates, reflecting their utilization potential for refractory ceramic applications.
| Original language | English |
|---|---|
| Pages (from-to) | 4840-4848 |
| Journal | Ceramics International |
| Volume | 45 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 1 Mar 2019 |
| MoE publication type | A1 Journal article-refereed |
Funding
The research has been supported by the Academy of Finland, project CeraTail funding decision # 292563 and by the Strategic Research Council at the Academy of Finland, project CloseLoop, funding decision # 303453.
Keywords
- Mining tailings
- Mullite
- Reaction sintering
- Refractory ceramics
- Utilization