The dissolution of nickel and cobalt from Caldag lateritic nickel ore using the combination of
sulphuric and ascorbic acids was investigated. The use of other organic acids, namely citric,
maleic and stearic acids, as synergistic reagents was studied for comparison. The results
revealed that the use of ascorbic and citric acids markedly improved the dissolution of cobalt
compared to the other two organic acids that only showed slight synergistic effect on the
leaching rate. In terms of nickel dissolution, ascorbic acid is the most effective synergist …