The Development Of New Polymer Flocculant And Its Application In The Alumina Industry

Aiming at improving sedimentation performance of red mud slurry in alumina manufacture, sodium polyacrylate with comparative high molecular weight was synthesized in bench scale by adopting compound inducing system.Additionally, industrialization experiment was carried out and relatively ideal sodium polyacrylate was got.Taking alumina manufacture of Zhongzhou branch China aluminum as example, the application of high polymer flocculation in each step was discussed in detail and studied deeply. The factors that influence the sedimentation performance were discussed too,and on which flocculant selection and optimal using condition for each step was obtained.Condition for synthesizing and polymerizing of sodium polyacrylate was:monomer neutralization degree 100%, inducing agent dosage 0.48%o, K2S2O8 0.2‰,NaHSO3 0.2‰,1,2-ethylenediamine8‰,assistant NaCl 8‰,urea 5‰, nitrogen pressure 0.6 Mpa, nitrogen ventilating time 11.5 min, inducing temperature 22℃,water bathing temperature first 30℃and anaphase 45℃,polymerizing time 8 h, drying temperature 110℃.Through comparing sedimentation performance of different flocculant used in red mud slurry sedimentation in alumina process, it is found that molecular and hudrolyzing degree and two main indexes for flocculant selection, and slurry has great selectivity on flocculant. Meanwhile the result showed that water quality for dissolving flocculant, dissolving temperature, charging model,concentration of the diluted slurry, slurry temperature, mixing condition after adding flocculant have obvious effect on sedimentation performance.