Evaluation of Geotextile Performance for the Filtration of Fine-Grained Tailings

Geotextile filters are an interesting solution to dewater tailings as they can be installed on existing ponds or be deployed during operation. However, filtration of the fine-grained tailings that are encountered in the oil sands and other mining industries raises several issues: blinding or clogging of the geotextile by the fine particles, or piping. Since the hydraulic conductivity of fine-grained tailings is generally too low for the ASTM D5101 standard test method for soil/geotextile system filtration compatibility, a test setup has been specifically developed and used to study the filtration behavior of needle-punched and heat-bonded nonwovens with various types of oil sands tailings. The permittivity of the geotextile/tailings systems was always several orders of magnitude lower than the water permittivity of the geotextile. On the other hand, no clogging or blinding was observed over more than 100 days. These results show that geotextiles offer great promise for the filtration of fine-grained tailings.