Dewatering Oil Sands Tailings with Degradable Polymer Flocculants

Sarang P Gumfekar; Thomas R Rooney; Robin A Hutchinson; João B P Soares

doi:10.1021/acsami.7b10302

Dewatering Oil Sands Tailings with Degradable Polymer Flocculants

ACS Appl Mater Interfaces. 2017 Oct 18;9(41):36290-36300. doi: 10.1021/acsami.7b10302. Epub 2017 Oct 4.

Authors

Sarang P Gumfekar¹, Thomas R Rooney², Robin A Hutchinson², João B P Soares¹

Affiliations

¹ Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 2V4, Canada.
² Department of Chemical Engineering, Queen's University , Kingston, Ontario K7L 3N6, Canada.

PMID: 28945965
DOI: 10.1021/acsami.7b10302

Abstract

We synthesized hydrolytically degradable cationic polymers by micellar radical polymerization of a short-chain polyester macromonomer, polycaprolactone choline iodide ester methacrylate (PCL₂ChMA) with two polyester units, and used them to flocculate oil sands mature fine tailings (MFT). We evaluated the flocculation performance of the homopolymer and copolymers with 30 mol % acrylamide (AM) by measuring initial settling rate (ISR), supernatant turbidity, and capillary suction time (CST) of the sediments. Flocculants made with trimethylaminoethyl methacrylate chloride (TMAEMC), the monomer corresponding to PCL_nChMA with n = 0, have improved performance over poly(PCL₂ChMA) at equivalent loadings due to their higher charge density per gram of polymer. However, MFT sediments flocculated using the PCL₂ChMA-based polymers are easier to dewater (up to an 85% reduction in CST) after accelerated hydrolytic degradation of the polyester side chains. This study demonstrates the potential of designing cationic polymers that effectively flocculate oil sands tailings ponds, and also further dewater the resulting solids through polymer degradation.

Keywords: degradable polymer; dewatering; flocculation; mature fine tailings; micellar radical polymerization.