Acid dissolution of mineral matrix in Green River oil shale

✍ Scribed by Krishnan Rajeshwar; Thomas Mraz; Robert Rosenvold; Joel DuBow

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 813 KB
• Volume: 63
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(84)90310-7

✦ Synopsis

The mineral matrix in Green River oil shale was partially removed by treatment with dilute HCI. The major ionic species in the solution from acid treatment (AT) were identified as NaC, A13+, Fe'+, Mg*', and Ca*+. The ion yields expected from reaction stochiometry, gravimetric analyses and comparison of calculated CO2 yields with measured levels were consistent with the fact that Na+ and A13' originated primarily from analcite: Fe*' and Mg*+ from dolomitic ankerite and Ca*+ from both dolomitic ankerite and calcite. Temperature and shale particle size were important parameters in the efficacy of AT. An increase in temperature and a decrease in particle size increased the rate of mineral dissolution. Fe*+ showed an anomalous trend in that the rate initially declined with increasing temperature after which it showed the usual increase with tern erature. The kinetics of ion build-up in the solution from AT were analysed in detail for the case of Al I: '. The Arrhenius expression was found to be valid only for finer particle sizes (e.g., -35, + 45 US mesh shale). A simple model is finally presented to account for the combined effect of temperature and shale particle size on mineral dissolution rates.