Preconcentration Feasibility of Gravity and Magnetic Techniques for Banded Hematite Jasper

The banded iron format ion of Banded Hematite Jasper is a very low grade iron ore that usually contains Fe in the range of 30-40% depending on the origin. Banded hemat ite Jasper obtained from Barb il region of India and assaying 41.9% Fe, 38.4% SiO2 and 0.4% A l2O3 was studied for pre-concentration of iron values adopting Jigging and Dry High Intensity Magnetic Separation. The pre-concentration studies were carried out with representative BHJ sample crushed and sized to -10+0.5mm, -6+0.5mm and-3+0.5mm. The dry high intensity magnetic separation process could achieve a best possible iron recovery of 69.9% with 51.4%Fe in the concentrate. The Jigging process could achieve a maximu m iron recovery of 68.5% with 57.3% Fe in concentrate. The optimu m recoveries and grade in both the cases were obtained for a feed size of-3+0.5mm. The results indicate that Jigging is a better pre-concentration technique when co mpared to Dry High Intensity Magnetic Separation.