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Title: Advanced research and technology. Direct utilization: recovery of minerals from coal fly ash. Technical progress report, July 1, 1981-September 30, 1981. [HiChlor and sintering processes]

Technical Report ·
OSTI ID:5412563

The primary objective of this investigation is to develop and/or improve methods for utilization of coal fly ash as a source of minerals. Processes are being studied for the recovery of aluminium oxide, iron oxides, and titanium oxide from fly ash and for utilization of the residues. Some of the highlights of the investigations on the HiChlor process development, and sinter processes for alumina recovery are as follows: computer calculations of the equilibrium conditions for the HiChlor process have shown that there may be economic and processing advantages to operation at conditions substoichiometric in chlorine; prechlorination, reaction of fly ash with Cl/sub 2/ and CO, has been shown to remove up to 40% of the Fe from a bituminous fly ash and up to 60% of the Fe from a subbituminous fly ash; physical characterization of alpha-alumina and leached fly ash pellets has shown both to have a low surface area and an ill-defined pore structure; the CO-Cl/sub 2/ chlorination conversion rate for alpha-alumina has been determined to be mass-transfer controlled in pellets under HiChlor process conditions; both anhydrous and aqueous product separation schemes for the HiChlor process have been examined, as well as alternate chlorination methods for coal fly ash; economic analysis of the HiChlor process has been updated to reflect current costs; experiments on the high-temperature sintering of limestone-fly ash mixtures have included alumina extraction and x-ray diffraction measurements of prepared sinter mixtures; addition of coal refuse to limestone-fly ash sinters has resulted in substantial increases in the amount of soluble alumina which can be extracted; sintering of mixtures of limestone and fly ash with several oxide additives has revealed that the concentration of phosphorus oxide in the sinters determines whether the sinters auto-disintegrate.

Research Organization:
Ames Lab., IA (USA)
DOE Contract Number:
W-7405-ENG-82
OSTI ID:
5412563
Report Number(s):
IS-4785; ON: DE82007855
Resource Relation:
Other Information: Portions of document are illegible
Country of Publication:
United States
Language:
English