TWO-STAGE FLOCCULATION OF FLUID FINE TAILINGS

摘要

A method for treating and disposal of fluid fine tailings utilizes two stages of thickening prior to disposal of the thickened tailings. The fluid fine tailings are adjusted to a sand-to-fines ratio of 0.5 to 1.3 using hydrocyclones or centrifuges in required. In a first stage of thickening a first flocculant is added to the fluid fine tailings which are fed to one or more conventional thickeners to produce a pumpable thickened tailings underflow having a solids content of between about 20 wt % to 40 wt %. The pumpable thickened tailings underflow is centrifugally pumped through a pipeline towards a disposal area. Adjacent the disposal area a second flocculant is added to the pumpable tailings underflow in a second stage of thickening to flocculate the tailings sufficient to produce a secondary thickened tailings underflow which when deposited has a solids content of about 50 wt % or higher at least one day after disposal. Alternatively, the second flocculant can be added prior to a paste thickener located adjacent the disposal area to further thicken the secondary thickened tailings underflow to a solids content of about 65 wt % for direct disposal at the disposal area.

主权项

1. A method for treating and disposing of fluid fine tailings having a sand-to-fine solids ratio (SFR) between about 0.5 to about 1.3 comprising:
in a first stage of thickening,
adding an amount of a first flocculant to the fluid fine tailings for forming a thickener feedstream; andfeeding the thickener feedstream to at least one thickener for producing a pumpable, first thickened tailings underflow; and pumping the first thickened tailings underflow to flow in a pipeline toward at least one disposal area; and in a second stage of thickening,
adding an amount of a second flocculant to the first thickened tailings underflow flowing through the pipeline for producing a secondary thickened tailings underflow for disposal at the at least one disposal area.