Processibility of athabasca oil sand: Interrelationship between oil sand fine solids, process aids, mechanical energy and oil sand age after mining

Abstract

Processibility curves have shown that strong inorganic bases or anionic surfactants are effective as process aids in the hot water extraction of bitumen from oil sand, but maximum bitumen recovery for each oil sand type is the same for both types of aid. Nonionic surfactants were not useful and there was no general relationship between recovery and surface tension or pH. Bitumen recovery could be correlated with the fine solids component of oil sand. The amount of NaOH required to reach maximum recovery and the rate of aging of oil sand were also functions of the fine solids content. Shear during slurrying was also found to be important, and it was shown that, without a certain amount of mechanical energy, good bitumen recovery could not be achieved, regardless of how much process aid was used. A theory of processibility is proposed to explain the interactions among process aids, mechanical energy, oil sand fines, and age of oil sand after mining.

Understanding Water‐Based Bitumen Extraction from Athabasca Oil Sands

“…There is a strong correlation between bitumen recovery and fines content: a high bitumen recovery at a low fines content (Sanford, 1983) and a low bitumen recovery at a high fines content. Although fines just below 44 µm are still quite coarse, it was found (Sanford, 1983;Cuddy, 2000) that there is a correlation between very fine solids (below 2-5 µm) and fines less than 44 µm. 12.…”

“…Under an optimal NaOH addition, maximum bitumen recovery from a high fines (i.e. >20% of mineral solids less than 44 µm) ore is lower than that for a low fines ore, (Sanford, 1983). Consequently these ores (containing say, >20% less than 44 µm) require addition of higher quantities of NaOH to achieve a maximum recovery.…”

“…3. For process aids, such as NaOH, Na 2 CO 3 , and Na 2 SiO 3 , there is an optimal concentration that provides maximum bitumen recovery (Sanford, 1983). 4.…”

“…8. Surfactants recovered from tailings ponds or commercial surfactants can be used as process aids, thereby decreasing the NaOH requirement (Sanford and Seyer, 1979;Sanford, 1983). 9.…”

Novel polymer aids for low‐grade oil sand ore processing

“…To improve bitumen recovery, chemical aids are often needed in bitumen extraction (Sanford, 1983;Taylor, 1988;Hepler and Smith, 1994). Particularly, for the processing of low-grade oil sand ores with a higher content of fines (mineral solid particles less than 44 m), process aids have to be used to obtain an acceptable bitumen recovery.…”