DISSOLUTION OF LATERITIC NICKEL ORE IN SULPHURIC ACID MEDIUM WITH POTASSIUM DICHROMATE

8th International Scientific Conference - SGEM2008, www.sgem.org, SGEM2008 Conference Proceedings/ ISBN: 954-918181-2, June 16-20, 2008, Vol. 1, 51-58 pp

ABSTRACT

In this study, leaching of Ni and Fe in suphuric acid medium with K2Cr2O7 was
investigated. The samples of the lateritic nickel ore were taken from Karacam
(Eskisehir) region of Turkey. Mineralogical investigations showed that the ore sample
contains, goethite, hematite, wustite, retgersite, gaspeite and clay type minerals together
with quartz. The shrinking core model was applied to the results of experiments
investigating the effects of leaching temperature range of 50–96 ◦C. Two equations
were applied from obtained results from each temperature value. Their correlation
coefficients for each temperature are calculated. These results indicate that the
dissolution rate of Ni is controlled by diffusion. The activation energy for the leaching
process was found to be 68.43 kJ/mol and the Arrhenius constant was calculated to be
8.231 s−1.

Keywords: Nickel, leaching, dissolution kinetics, H2SO4, K2Cr2O7, Karacam (Eskisehir), Turkey.