Alumina miniplant operations--overall mass balance for clay-HCl acid leaching.
Sawyer-DL Jr.; Turner-TL; Hunter-DB
Boulder City, NV: U.S. Department of the Interior, Bureau of Mines, RI 8759, 1983 Apr; :1-29
To provide technology that can help decrease the dependence of the U.S. aluminum industry on imported bauxite, the main ore of aluminum, the Bureau of Mines is investigating the extraction of aluminum from abundant domestic reserves of kaolinitic clay. Miniplant studies of the continuous leaching of calcined kaolin with boiling 25-pct hcl acid resulted in a 93- to 99-pct extraction of the acid-soluble alumina in the calcined kaolin feed. Data are presented for an acid leaching study carried out in three or four continuously stirred tank reactors (cstr) in series, feed rates of 100 to 250 lb/hr of calcined kaolin, and total nominal residence times of 0.7 to 2.3 Hr. A material balance for a 176-lb/hr calcined kaolin feed rate in a circuit consisting of three reactors, four classifiers, and five thickeners is given. Data provide detailed compositional and physical information for calcined kaolin, process liquors, and acid-leached residue solids.
Acid treatment; Aluminum; Clay minerals; Hydrochloric acid; Kaolinite; Leaching; Materials recovery; Roasting
IH; Report of Investigations
NTIS Accession No.
Boulder City, NV: U.S. Department of the Interior, Bureau of Mines, RI 8759