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Title: Aluminum recovery from coal fly ash by high temperature chlorination

Thesis/Dissertation ·
DOI:https://doi.org/10.2172/5205054· OSTI ID:5205054
 [1]
  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
Resource Relation:
Other Information: Thesis
Country of Publication:
United States
Language:
English