Abstract:An Australian nickel laterite ore was heap leached with the two stage countercurrent process. The effects of particle size, acid concentration, leaching time, and heap high on nickel leaching rate were investigated. The results show that the nickel leaching rate is up to 80.28% in the whole process. In the first stage, the ore with particle size of 2~8 mm is leached for 16 days with second stage leaching lixivium, and in the second stage, the first leaching residue is heap leached for 60 to 70 days with the sulfuric acid concentration of 22%.