Synthesis of Calcium Aluminates from Non-Saline Aluminum Dross

The present work examines the synthesis of tricalcium aluminate (for use as a synthetic slag) from the non-saline dross produced in the manufacture of metallic aluminum in holding furnaces. Three types of input drosses were used with Al<sub>2</sub>O<sub>3</sub> contents rangi...

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Bibliographic Details
Main Authors: Félix Antonio López, María Isabel Martín, Francisco José Alguacil, Mario Sergio Ramírez, José Ramón González
Format: Article
Language:English
Published: MDPI AG 2019-06-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/12/11/1837
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Summary:The present work examines the synthesis of tricalcium aluminate (for use as a synthetic slag) from the non-saline dross produced in the manufacture of metallic aluminum in holding furnaces. Three types of input drosses were used with Al<sub>2</sub>O<sub>3</sub> contents ranging from 58 to 82 wt %. Calcium aluminates were formed via the mechanical activation (reactive milling) of different mixtures of dross and calcium carbonate, sintering at 1300 &#176;C. The variables affecting the process, especially the milling time and the Al<sub>2</sub>O<sub>3</sub>/CaO molar ratio, were studied. The final products were examined via X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The reactive milling time used was 5 h in a ball mill, for a ball/dross mass ratio of 6.5. For a molar relationship of 1:3 (Al<sub>2</sub>O<sub>3</sub>/CaO), sintered products with calcium aluminate contents of over 90% were obtained, in which tricalcium aluminate (C<sub>3</sub>A) was the majority compound (87%), followed by C<sub>12</sub>A<sub>7</sub> (5%).
ISSN:1996-1944