Some hydrometallurgical studies on Indonesian low-grade nickel laterite

Nickel laterite Part 1 – microstructure and phase characterisations during reduction roasting and leaching

“…In addition, a number of studies have been carried out to determine the effect of the process parameters on the nickel recovery. 4,[12][13][14][15][16][17][18][19] Caron 4 investigated the effect of the physical nature of the ore and its original chemistry, particle size, reduction temperature, leaching temperature, leaching liquor composition and other reduction and leaching practices on the nickel recovery from laterites. De Graaf 12,13 studied the effect of different reduction roasting and leaching conditions on the nickel recovery from limonitic and saprolitic laterite ores, and reported that effective reduction occurs when it is carried out at partial pressure of H 2 or CO of at least 15 199 Pa (0?15 atm) at a temperature range of 550-650uC.…”

“…None of the studies 4,[12][13][14][15][16][17][18][19] described above provide information on the changes on the microstructure and nickel distribution in the phases at microscopic level as a result of the reduction and leaching; only limited information can be found in literature. [20][21][22] During the reduction roasting and leaching, complex changes in the materials' microstructure, phase, nickel distribution and other characteristics are occurring.…”