Corrosion resistance of materials in the aqueous hydrochloric acid environments associated with the recovery of aluminum from kaolinitic clays.
Covino BS Jr.; Rosen M; Riley WD
Avondale, MD: U.S. Department of the Interior, Bureau of Mines, RI 8565, 1981 Oct; :1-28
The Bureau of Mines has conducted a laboratory and field corrosion testing program to determine materials of construction for the leaching and gas-sparging crystallization environment of the clay-HCl process in order to more fully utilize the alumina from domestically available kaolinitic clays. Laboratory tests were used to determine the corrosion rates of 22 metals and alloys by weight-loss measurements in these two environments of the process. The results of this laboratory study were used both to suggest metals and alloys for field testing and to determine the effect of the individual solution components on the corrosion behavior of the metals and alloys. Results from the field tests were used to recommend Ta, Ta-2.5w, and Ta-10w for construction of the agitators for the leaching process. The metals and alloys recommended for construction of the gas-sparging crystallizer heat exchangers were Ta, Ta-2.5w, Ta-10w, Nb, Nb-1Zr, Nb-3Zr, Nb-28Ta-10w-1Zr, Nb-10HF- 1Ti, and Zr for the first stage and Ta, Ta-2.5w, Ta-10w, Nb-28Ta-10w- 1Zr, Nb, Nb-10HF-1Ti, and Zr for the second stage.
Alloys; Aluminum; Clay minerals; Corrosion resistance; Corrosion tests; Crystallization; Design criteria; Field tests; Heat exchangers; Hydrogen chloride; Kaolinite; Laboratory equipment; Leaching; Molybdenum; Nickel; Niobium; Procedures; Samples; Tantalum; Titanium; Zirconium
IH; Report of Investigations
NTIS Accession No.
Avondale, MD: U.S. Department of the Interior, Bureau of Mines, RI 8565