Report of Investigations 8978: Pressure Leaching Alumina from Raw Kaolinitic Clay Using Hydrochloric Acid

Details

• Personal Author:
  Sawyer, Dwight L. Jr. ; Turner, Theodore L.
• Corporate Authors:
  United States. Bureau of Mines
• Description:
  The Bureau of Mines studied alumina extraction from uncalcined, kaolinitic day at temperatures from 100 deg. to 250 deg. C using 20- or 27-wt-pct-hcl concentrations and with an acid-to-clay ratio of from 0.8 to 1.4 Times stoichiometric. Autogenous digestion pressures ranged from atmospheric pressure to about 900 psia. Extraction of 96 pct of the alumina was obtained by hcl leaching at temperatures and leaching times that varied from 100 deg. C for 120 h to 200 deg. C for 15 min. Hydrochloric acid stoichiometry of the reaction al2o3.2Sio2.2H2o + 6hcl-> 2alcl3 + 2sio2 + 5h2o was studied at different temperatures and leaching times in a 750-ml tetrafluoroethylene-polymer-lined autoclave. A combination of high temperature and 20 wt pct excess hcl promoted rapid and almost quantitative extraction of alumina (99 pct in some tests). Additional Bureau data obtained with 35-ml tantalum bombs and leaching tests with added fluoride are also provided. At high temperatures, the addition of fluoride did not result in a significant improvement over hcl alone and was deleterious to the filtering properties of the digest residue. [Description provided by NIOSH]
• Subjects:
  Filtration Hydrochloric Acid Mining Occupational Health Safety Solvents
• Keywords:
  Aluminum-dioxide Clay-minerals Hydrochloric-acid Kaolinite Leaching Performance-evaluation Solvent-extraction
• Series:
  Mining Publications
• Subseries:
  Report of Investigations
• ISSN:
  1066-5552 (print)
• Publisher:
  United States. Bureau of Mines
• Document Type:
  Text
• Genre:
  Case Report
• Rights:
  Public Domain
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  26 pdf pages
• NIOSHTIC Number:
  nn:10004659
• NTIS Accession Number:
  PB86-126729
• Citation:
  Reno, NV: U.S. Department of the Interior, Bureau of Mines, RI 8978, 1985 Jan; :1-18
• Federal Fiscal Year:
  1985
• Peer Reviewed:
  False
• Source Full Name:
  Reno, NV: U.S. Department of the Interior, Bureau of Mines, RI 8978
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:c790afd702e45a939d4b339556e2f81eb535b73eea53a21e772a34edb7555ef8824bb08529fb184cab734cd6f0cac4ba4ff0f4eee0873a5bcef90ef1237c0437
• Download URL:
  https://stacks.cdc.gov/view/cdc/201772/cdc_201772_DS1.pdf
• File Type:
  [PDF - 1.53 MB ]