Abstract: In order to improve the technical indicators of pyrometallurgical process of the low grade laterite nickel ore，the pyrolysis properties of the low grade nickel laterite ore from Indonesia was studied.The results showed that the laterite belong to the typical transition layer laterite.The main mineral composition of the laterite are lizardite，goethite，silica，greenalite，schweizerite and kaolinite.Nickel mainly occur in the Ni-riched silicate ores，such as serpentine and olivine.And part of nickel occurrence as nickel oxide in goethite.The pyrolysis analysis results indicated that first weight loss of the laterite occurred at 86 ℃，which form an endothermic peak and the main violent is H₂O.The first stage corresponded to the evaporated of the free water.The second weight loss of the laterite occurred at 268 ℃，which form an endothermic peak and the main violent is H₂O.The second stage corresponded to the dehydroxylation of goethite.The third weight loss of the laterite occurred at 589 ℃，which form an endothermic peak and the main violent is H₂O.The third stage corresponded to the dehydroxylation of kaolinite and lizardite.The laterite form an exothermic peak at 816 ℃，and the quality almost no change，which caused by lizardite pyrolysis produce the amorphous silicate，and the amorphous silicate recrystallization to the forsterite (Mg₂SiO₄) and pyroxene (MgSiO₃).The last weight loss of the laterite occurred at 1 126 ℃，which form an exothermic peak，and the main violent is CO₂.The last stage corresponded to the dolomite decomposed.The experimental results can be somewhat conductive to improve the pyrogenic process of the laterite.

Key words: Nickel laterite, Pyrolysis, TG-MS, TG-dTG, DSC