Advancements of fluid fine tailings treatment technologies through fundamental research

Fluid fine tailings (FFT) management is one of the main challenges that oil sand developers continue to face. Syncrude Canada Ltd, independently or in collaboration with Canada’s Oil Sands Innovation Alliance (COSIA) member companies, has developed various technologies to accelerate FFT dewatering to meet progressive mine closure and reclamation objectives. One of the technologies is FFT clay treatment that targets the problematic clays in FFT. The basis of this step-out technology is the use of a polymeric flocculant to enlarge the effective size of clays and a collector to change the clay surfaces from hydrophilic to hydrophobic. In this way, the treated FFT dewaters very fast. An effective, easy to use collector is key to the success of this technology. Collectors are chemical compounds added to FFT that change the clay hydrophobicity, promote aggregation of clay particles and assist in FFT dewatering. Theoretically, it is possible to directly use a cationic collector or a combination of a metal ion and an anionic collector to make the negatively charged FFT clays hydrophobic. Building on this concept, several process technology scenarios have been developed and tested. This paper demonstrates how fundamental research provides a simple and cost-effective method for screening collectors for operational FFT clay treatment.