Mineral phase transformation in coal gangue by high temperature calcination and high-efficiency separation of alumina and silica minerals
| Autor: | Fengqin Liu, Mingzhuang Xie, Ke Chaoyang, Hongliang Zhao, Xu Zhiqian |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Sodium silicate Mullite complex mixtures law.invention Biomaterials chemistry.chemical_compound Caustic leaching law otorhinolaryngologic diseases Kaolinite Calcination Desilication Metakaolin Mineral Mining engineering. Metallurgy business.industry Metallurgy Metals and Alloys Coal mining technology industry and agriculture TN1-997 Coal gangue respiratory system Phase transformation Surfaces Coatings and Films respiratory tract diseases chemistry Ceramics and Composites Leaching (metallurgy) business |
| Zdroj: | Journal of Materials Research and Technology, Vol 14, Iss, Pp 2281-2288 (2021) |
| ISSN: | 2238-7854 |
| Popis: | Coal gangue is the solid waste from the coal mining process. About 1 billion tons of coal gangue is discharged every year in the world. Coal gangue is usually piled up in the large areas and difficult to be used. Phase transformation and separation of alumina and silica minerals in coal gangue are studied in this paper in order to prompt the resource utilization of coal gangue. The results show that the phase transformation of kaolinite in coal gangue during high-temperature calcination is in the following way: kaolinite → metakaolin → spinel → mullite. Active silica mineral is released during the phase transition process, which can be separated from other minerals by caustic leaching. The optimal calcination temperature of coal gangue is 1050 ± 50 °C while the caustic leaching temperature is 85 °C and the leaching time should be kept between 60 and 80 min. The modulus of the sodium silicate solution can reach 1.0–1.1 and the alumina to silica ratio (A/S) of the desilicated residue can be raised to 1.7. |
| Databáze: | OpenAIRE |
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