Humic substances extracted from lignite mainly consist of fulvic acids (FA) and humic acids (HA), which have been successfully used as good composite binders for iron ore pellets in laboratory tests and industrial production. However, there exists a general lack of understanding of the interaction between humic substances and iron ore particles surfaces. In this research, by means of zeta potential measurements, Fourier Transform Infrared (FTIR) spectrum, colorimetric method and Environmental Scanning Electron Micrograph (ESEM) imaging, the adsorption behaviours of FA and HA onto the surfaces of iron ore particles are investigated. The zeta potential results indicate that adsorption of FA on the iron ore particles can be characterised by specific and electrostatic interactions, while adsorption of HA is by electrostatic and chemical adsorption interactions. FTIR spectrum results show that adsorption force of FA on the iron ore particle surfaces is stronger than that of HA. From results of colorimetric method, compared with HA, adsorption amount and adsorption rate of FA is more and faster, respectively. FA molecule presents on the surface of magnetite in the shape of an araneose network structure according to the ESEM images, while HA molecule appears on the surface of magnetite in the form of small flocs or microclusters._x000D_
Humic substances are effective to iron ore pelletisation._x000D_
Comparsion of agglomeration results show that the different mechanisms of adsorption result in varied agglomeration behaviours. Theses findings above would be beneficial to the implications of composite binder for agglomeration._x000D_
CITATION:Han, G, Zhang, Y, Huang, Y, Li, G and Jiang, T, 2010. Adsorption behaviours of humic substances onto iron ore particle surface, in Proceedings XXV International Mineral Processing Congress (IMPC) 2010, pp 163-172 (The Australasian Institute of Mining and Metallurgy: Melbourne).