Article pubs.acs.org/EF
Mineralogy and Surface Chemistry of Alberta Oil Sands: Relevance to Nonaqueous Solvent Bitumen Extraction Marek Osacký,*,†,‡ Mirjavad Geramian,† Peter Uhlík,‡ Mária Č aplovičová,‡,§ Zuzana Danková,∥ Helena Pálková,⊥ Martina Vítková,# Milota Kovácǒ vá,∥ Douglas G. Ivey,† Qi Liu,† and Thomas H. Etsell† †
Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada Department of Economic Geology, Comenius University, Mlynská dolina, Ilkovičova 6, 84215 Bratislava, Slovakia § STU Centre for Nanodiagnostics, Slovak University of Technology, Vazovova 5, 81243 Bratislava, Slovakia ∥ Institute of Geotechnics, Slovak Academy of Sciences, Watsonova 45, 04001 Košice, Slovakia ⊥ Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 84536 Bratislava, Slovakia # Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 16521 Prague 6, Czech Republic ‡
S Supporting Information *
ABSTRACT: The mineralogy, chemistry, surface properties, and pore structure characteristics of the four different petrologic types of Alberta oil sands were determined in order to better understand their impact on nonaqueous solvent bitumen extraction. Quartz, clay minerals, and carbonates were the main mineral constituents of the studied samples. With increasing weight percentage of clay minerals, the solvent bitumen extraction (by the Dean−Stark procedure using toluene) decreased. Fine grained illite and illite-smectite had more detrimental effect on solvent bitumen extraction than coarse grained kaolinite. The pore structure data revealed that the extractability of bitumen from the oil sands depends on accessibility, more specifically on the size of bitumen-filled pores, by the solvent. The relative abundance and size of pores in the oil sands were controlled by mineral composition and particle size. Fine size fractions were typically enriched in kaolinite and 2:1 clay minerals (illite and illitesmectite) and contained small pores, with diameters of ∼100 and ∼10 nm, respectively. Coarse size fractions were usually rich in quartz and contained large pores with diameters greater than 200 nm. The efficiency of nonaqueous bitumen extraction was significantly higher for coarse grained, quartz-rich oil sands in which the organic matter was distributed mainly at a scale of greater than 200 nm compared with fine grained, clay-rich oil sands where organic matter occurred as meso-macropore filling material within clay mineral aggregates. Overall, the finest (45 μm, 2−45 μm,
