INVESTIGATION ON THE EFFECT OF ULTRASONIC PRETREATMENT ON SELECTIVE SEPARATION OF IRON VALUES FROM IRON-ORE TAILINGS BY FLOCCULATION

Selective flocculation studies were carried out on Barsuan iron ore ta ilings having 50.5% iron, 7.2% alumina, and 7.8% silica in the absence and presence of ultrasonication at different experimental conditions using sodium hexametaphosphate as a dispersant and starch as a floccul ant. The imposition of ultrasonication resulted in a marked improvemen t in grade as well as recovery. The results indicate that ultrasonicat ion is able to mitigate the adverse effects of gangue materials. A con centrate assaying 59% iron with 75% recovery could be obtained without ultrasonication, while the application of ultrasonication led to an i mprovement in concentrate grade to 65% with a corresponding increase i n recovery to 91%. The improvement is attributed to the disruption cau sed at a solid/liquid interface which results in favorable modificatio n of the mineral surface, facilitating selective adsorption of floccul ant on the iron ore fines. This, in turn, leads to enhancement in sele ctivity and recovery. In addition, ultrasonication also leads to effec tive dispersion, causing enhanced activity.