Effect of Operating Parameters on the Performance of Spiral Concentrator

Spiral concentrator, a critical device in the mineral sand beneficiation circuit, separates minerals based on their specific gravity differences. The effect of diffe-rent operating parameters on the performance of Spiral has been studied through optimization experiments at different feed flow rates and splitter positions for four feed pulp densities ranging from 25- 10%. The raw sand used in exper-imentation contains 12.5% slimes and 11% heavy mineral
concentrate, out of which 80% was in the particle size range of —250 + 106 pm.
It has been observed that with increase in feed flow rate the grade of concentrate increased but as expected the recoveries decreased significantly. Medium feed flow rate, i.e, 3.0-3.5 m3/hr was found to be optimum in order to obtain the concentrate with greater than 93.5% HMC and
high recoveries of >96%. Concentrate grade improved as the feed pulp densities increased.The Spiral concentrator has performed better at feed pulp density of 30% by producing
concentrate of high grade (93.5%) and with highest recoveries of 96%. The desliming of raw sand has been done using using hydrocyclone. When the deslimed feed is fed to the spiral, high concentrate grades has been produced with very high recoveries as high as 98%.