Mining tailings as raw materials for reaction-sintered aluminosilicate ceramics: Effect of mineralogical composition on microstructure and properties

Marjaana Karhu (Corresponding Author), Juha Lagerbom, Soili Solismaa, Mari Honkanen, Arnold Ismailov, Marja Liisa Räisänen, Elina Huttunen-Saarivirta, Erkki Levänen, Päivi Kivikytö-Reponen

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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 languageEnglish
Pages (from-to)4840-4848
Number of pages9
JournalCeramics International
Issue number4
Publication statusPublished - 1 Mar 2019
MoE publication typeA1 Journal article-refereed



  • Mining tailings
  • Mullite
  • Reaction sintering
  • Refractory ceramics
  • Utilization

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