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Title: Chemistry of the recovery of alumina from fly ash

Abstract

A comprehensive investigation of several methods for the recovery of aluminum from fly ash was carried out. The objective was to investigate and evaluate methods for the recovery of high purity alumina which could be readily substituted in the existing aluminum industry for imported alumina or for alumina derived from imported bauxite. Here, the chemistry of the direct acid leach, Calsinter, and Pressure Digestion-Acid Leach methods is reviewed. Only partial aluminum solubilization (30 to 60%) can be achieved by direct acid leaching of eastern ashes since a portion of the aluminum is in crystalline mullite which is relatively acid insoluble. Of the three acids tested (HCl, H/sub 2/SO/sub 4/, and HNO/sub 3/), HCl proved to be the most effective. Suitable leach conditions for eastern fly ashes were found to be 2 h at reflux temperature. High aluminum solubilization (>90%) from eastern ashes can be obtained by acid leaching, following a basic treatment to chemically alter the mullite. A high temperature sinter with lime or scrubber sludge (Calsinter) can be employed to form anorthite and/or gehlenite, or a pressure digestion reaction with caustic soda (PDAL) can be used to form zeolite X. Following these reactions, the aluminum can be solubilized bymore » acids.« less

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Oak Ridge National Lab., TN (USA)
OSTI Identifier:
5453830
Report Number(s):
CONF-8110137-5
ON: DE84003318
DOE Contract Number:  
W-7405-ENG-26
Resource Type:
Conference
Resource Relation:
Conference: Symposium on resource recovery and environmental issues of industrial solid wastes, Gatlinburg, TN, USA, 28 Oct 1981
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; ALUMINIUM OXIDES; RECOVERY; FLY ASH; LEACHING; ACIDIZATION; HYDROCHLORIC ACID; MULLITE; SLUDGES; ZEOLITES; AEROSOL WASTES; ALUMINIUM COMPOUNDS; ASHES; CHALCOGENIDES; DISSOLUTION; HYDROGEN COMPOUNDS; INORGANIC ACIDS; INORGANIC ION EXCHANGERS; ION EXCHANGE MATERIALS; MATERIALS; MINERALS; OXIDE MINERALS; OXIDES; OXYGEN COMPOUNDS; RESIDUES; SEPARATION PROCESSES; WASTES; 320305* - Energy Conservation, Consumption, & Utilization- Industrial & Agricultural Processes- Industrial Waste Management

Citation Formats

Kelmers, A D, Canon, R M, Egan, B Z, Felker, L K, Gilliam, T M, Jones, G, Owen, G D, Seeley, F G, and Watson, J S. Chemistry of the recovery of alumina from fly ash. United States: N. p., 1981. Web.
Kelmers, A D, Canon, R M, Egan, B Z, Felker, L K, Gilliam, T M, Jones, G, Owen, G D, Seeley, F G, & Watson, J S. Chemistry of the recovery of alumina from fly ash. United States.
Kelmers, A D, Canon, R M, Egan, B Z, Felker, L K, Gilliam, T M, Jones, G, Owen, G D, Seeley, F G, and Watson, J S. 1981. "Chemistry of the recovery of alumina from fly ash". United States.
@article{osti_5453830,
title = {Chemistry of the recovery of alumina from fly ash},
author = {Kelmers, A D and Canon, R M and Egan, B Z and Felker, L K and Gilliam, T M and Jones, G and Owen, G D and Seeley, F G and Watson, J S},
abstractNote = {A comprehensive investigation of several methods for the recovery of aluminum from fly ash was carried out. The objective was to investigate and evaluate methods for the recovery of high purity alumina which could be readily substituted in the existing aluminum industry for imported alumina or for alumina derived from imported bauxite. Here, the chemistry of the direct acid leach, Calsinter, and Pressure Digestion-Acid Leach methods is reviewed. Only partial aluminum solubilization (30 to 60%) can be achieved by direct acid leaching of eastern ashes since a portion of the aluminum is in crystalline mullite which is relatively acid insoluble. Of the three acids tested (HCl, H/sub 2/SO/sub 4/, and HNO/sub 3/), HCl proved to be the most effective. Suitable leach conditions for eastern fly ashes were found to be 2 h at reflux temperature. High aluminum solubilization (>90%) from eastern ashes can be obtained by acid leaching, following a basic treatment to chemically alter the mullite. A high temperature sinter with lime or scrubber sludge (Calsinter) can be employed to form anorthite and/or gehlenite, or a pressure digestion reaction with caustic soda (PDAL) can be used to form zeolite X. Following these reactions, the aluminum can be solubilized by acids.},
doi = {},
url = {https://www.osti.gov/biblio/5453830}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1981},
month = {1}
}

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