Accelerating the reclamation of the oil sands mining operation is also a pressing project that has sparked an array of approaches from both inside the industry and out. Among the many contenders is Calgary-based Technika Engineering, which observed the issues with conventional mature fine tailings (MFT) reclamation technologies using dredges and barges with submersible pumps.
“We thought there had to be a better approach,” said Radé Svorcan, the company’s president. “So we set out to design it.”
Technika has developed what it calls the Tailings Recovery System (TRS). Oil sands MFT have considerable shear strength and viscosity that increase with the depth of the ponds, which typically reach 30 metres deep. Due to debris in the MFT and its rheology, conventional technologies using dredges and barges with submersible pumps encounter MFT dilution at the suction point, and clogging. TRS technology uses a caisson-type telescoping shell structure located at the pond surface that can go down to a 15-plus metre depth to leverage the principle of hydraulic pressure balance to bring MFT to the surface. “Because the MFT is on the surface within the TRS, it’s much easier to recover it and the challenges of MFT dilution and pump clogging are addressed. We are using the natural hydraulics to draw the MFT up,” said Svorcan.