Surfactant-assistant atmospheric acid leaching of laterite ore for the improvement of leaching efficiency of nickel and cobalt

摘要

Atmospheric acid leaching has attracted great attention from scientists due to the mild leaching conditions. However, the leaching efficiency of nickel is lower than that using high pressure acid leaching. Herein, we report the use of a surfactant (e.g., stearyltrimethyl ammonium chloride, STAC) to improve the leaching efficiency of Ni. The effects of surfactant type, ore-surfactant ratio, leaching temperature, and leaching duration on the leaching ratio of Ni were investigated. The use of STAC resulted in the high efficiency for Ni leaching at 100 degrees C with an ore-surfactant ratio of 15 and leaching duration of 8 h. The leaching efficiencies of Ni and Co were significantly higher than that of atmospheric acid leaching. The surface tension and viscosity of the leaching solution, and the zeta potential of the leached residue were analyzed to investigate the mechanism of the leaching process. The changes of interfacial properties improved ionic diffusion and decreased metal adsorption, which further lead to the increasing of leaching efficiency. (C) 2019 Elsevier Ltd. All rights reserved.