Bb. Kar et al., Design of experiments to study the extraction of nickel from lateritic oreby sulphatization using sulphuric acid, HYDROMETALL, 56(3), 2000, pp. 387-394
Experiments were designed to optimize the sulphatization of a mechanical mi
xture of chemically pure nickel and iron oxide and a lateritic ore using su
lphuric acid. The significance of various parameters and their selectivity
for nickel extraction over iron have been established. The interaction amon
g the operating parameters has been studied using statistically designed ex
periments and the data, thus obtained for the pure system, was correlated w
ith that for the lateritic ore. Regression equations were formulated for bo
th systems and the extraction was represented as a Function of response var
iables. The accuracy of the equation has been verified by Fisher's adequacy
test. It was observed that the coefficient of temperature was the most dom
inant, Followed by acid concentration. Interestingly, the time factor induc
es a small effect on extraction. The process has been further optimised usi
ng the steepest ascent method. (C) 2000 Elsevier Science B,V, All rights re
served.