Aluminum recovery from coal fly ash by high temperature chlorination

Thesis/Dissertation · Sat Oct 01 04:00:00 EDT 1977

DOI:https://doi.org/10.2172/5205054· OSTI ID:5205054

Wijatno, Hendra ^[1]

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1. Iowa State Univ., Ames, IA (United States)

A study of aluminum recovery from power plant fly ash by high temperature chlorination was undertaken to demonstrate that fly ash could be a potential source of aluminum, iron and possibly silicon. Magnetic separation of the iron oxide served as a first step to alleviate the iron contamination problem. However, the agglomeration of some iron oxide with alumina and silica made it difficult to completely separate the iron from the fly ash. Further iron separation was achieved by chlorinating the nonmagnetic ash fraction at 550°C for 30 minutes. This reduced the iron oxide content to less than 4 percent by weight. Chlorine flow rates affected the reaction rate much more drastically than temperatures. This suggested that diffusion was the major rate-controlling step. Besides Fe₂O₃, Al₂O₃ and SiO₂, other oxides such as CaO, K₂O, Na₂O and MgO might have complicated the alumina recovery by forming individual chlorides or complexes. Investigating methods for separating more Fe₂O₃, and possibly CaO, K₂O, Na₂O and MgO from the nonmagnetic ash fraction before chlorinating it is highly recommended.

• Research Organization: Ames Lab., Ames, IA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5205054
• Report Number(s): IS-T--777
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010800* -- Coal
Lignite
& Peat-- Waste Management
AEROSOL WASTES
ALUMINIUM
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CHLORINATION
CONCENTRATORS
DUST COLLECTORS
ELEMENTS
FLY ASH
FORECASTING
FOSSIL-FUEL POWER PLANTS
HALOGENATION
MAGNETIC SEPARATORS
METALS
PHYSICAL PROPERTIES
POWER PLANTS
PRODUCTION
RECOVERY
SEPARATION PROCESSES
THERMAL POWER PLANTS
USES
WASTE PRODUCT UTILIZATION
WASTES