Influence of thermal treatment on phase transformation and dissolubility of aluminosilicate phase in red mud

Nan Ye, Jing Zhu, Jianwen Liu, Yalin Li, Xinyuan Ke, Jiakuan Yang

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)

Abstract

Red mud is a solid waste residue from the caustic soda leaching of bauxite ores to produce alumina by the Bayer process. Red mud contains large quantity of alkali and aluminosilicate, so it is potentially available to prepare inorganic polymeric materials by geopolymerisation process. However, the activity or dissolubility of the aluminosilicate phases in red mud is significantly poor, which constraints the geopolymerisation process. Therefore, some pretreatment process for red mud is necessary to improve the adhesive property and dissolubility of Bayer red mud. In this study, mineral phase transformation and dissolubility of a typical red mud sample were studied under different thermal treatment processes. The thermal behavior of the red mud was studied by TG-DTA. The crystalline phases of the samples calcined at 200-1000 °C for different hours were determined by XRD, and the dissolubility was determined by alkaline leaching test. The TG-DTA pattern shows no obvious endothermic or exothermic peaks, and the weight loss increases continuously as the temperature rises, which indicates that the crystalline phases transform continuously as the temperature rises, consistent with the XRD results. As the calcination temperature rises from 200 to 800 °C, several kinds of crystalline phase in original red mud, including gibbsite, katoite, muscovite, natrodavyne disappeared in succession, accompanied with the formation of nepheline, gehlenite, sodium aluminum silicate, and some amorphous aluminosilicate. The calcined products are more likely to dissolve. But when it rises over than 800 °C, the content of gehlenite increases, and the phase of which is stable. As the calcination temperature rises from 200 to 1000 °C, the dissolubility of aluminosilicate in the red mud under high alkaline conditions increases firstly and then decreases after over 800 °C. Therefore, the optimum temperature of thermal treatment for red mud is about 800 °C. This study could contribute to the following preparation of geopolymeric material made from red mud, especially the pretreatment process of red mud.

Original languageEnglish
Title of host publicationConcrete with Smart Additives and Supplementary Cementitious Materials
PublisherMaterials Research Society
Pages41-46
Number of pages6
Volume1488
ISBN (Print)9781632660862
DOIs
Publication statusPublished - 1 Jan 2012
Event21st International Materials Research Congress, IMRC 2012 - Cancun, Mexico
Duration: 12 Aug 201217 Aug 2012

Conference

Conference21st International Materials Research Congress, IMRC 2012
CountryMexico
CityCancun
Period12/08/1217/08/12

Keywords

  • Aluminosilicate
  • Dissolubility
  • Geopolymer
  • Red mud
  • Thermal treatment

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Ye, N., Zhu, J., Liu, J., Li, Y., Ke, X., & Yang, J. (2012). Influence of thermal treatment on phase transformation and dissolubility of aluminosilicate phase in red mud. In Concrete with Smart Additives and Supplementary Cementitious Materials (Vol. 1488, pp. 41-46). Materials Research Society. https://doi.org/10.1557/opl.2012.1546