280991 Dewatering Oil Sand Tailings Using Calcite

Tuesday, October 30, 2012: 5:20 PM
414 (Convention Center )
Anwesha Basu, Chemical Engineering, Pennsylvania State University, University Park, PA and Darrell Velegol, Chemical Engineering, Penn State University, University Park, PA

Bituminous sands contain petroleum that can be extracted by various means.  As the petroleum is obtained from the sands, an additional side product consists of various types of clays and minerals, which compose the “tailings”.  Currently there are more than 50 square kilometers of tailings ponds in Canada.  One component of the tailings is “mature fine tailings” (MFTs), which are clay particles that have settled, but still contain a large enough fraction of water that the material is not trafficable, and thus cannot be used for roads or buildings.  There are various strategies that have been developed for consolidating MFTs, such as Consolidated Tailings; however, each technology has challenges, especially for already-existing tailings ponds.  One type of tailing technology being pursued is the addition of chemical species that improves the consolidation process.  For example, gypsum (CaSO4) has been added, which improves the dewatering of the MFTs.  In this talk we study the addition of calcite to tailings (CaCO3), using various methods.  We examine the effects on dewatering, showing that we obtain an enhanced removal of water.  A further interesting aspect of CaCO3 use is the resulting layering of the MFTs, including a final bitumen layer atop the others.This talk will discuss the approach used with CaCO3, the results for dewatering and consolidation, improved trafficability of clay and potential transport, thermodynamic and surface chemistry mechanisms of action.

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See more of this Session: Fundamentals of Interfacial Phenomena III
See more of this Group/Topical: Engineering Sciences and Fundamentals