Optimizing Flocculation-Sedimentation for Regeneration of Dual-Alkali Flue Gas Desulphurization Scrubbing Solution

摘要

A new method was developed to optimize thefloccu-lation-sedimentation process for regeneration of dual-alkali flue gas desulphurization scrubbing solution. Experimental data of top loading settling of CaSO_3 suspended solids (SS) in the slurry were utilized to define the settling velocity curve for solid/liquid separation without a visible mud-line. The settling velocity curve was employed for identifying the best flocculation conditions to achieve effective regeneration of the scrubbing solution. For the case studied, the optimum flocculant/dose was 4.41 × 10~(-3) HPAM/SS (mass ratio). While a basic pH enhanced the separation, a high ionic strength had an adverse effect because of the change of ζ potential. The predicted SS removal efficiency for a horizontal sedimentation tank was verified by actual data. This method may be employed for optimizing solid/liquid separation of other high SS feed Streams.