Adsorption of lignite humic acid onto magnetite particle surface

Modified humic acid (MHA) binder based on lignite humic substances is a novel sort of promising organic binder for iron ore pellets. Humic acid (HA) is one of the main ingredients of MHA binder. Pure HA was firstly isolated from lignite and then adsorption of HA onto magnetite particle surface was investigated. The final results indicate that the adsorption of HA onto magnetite surface accords with Langmuir model well, and it is evidently influenced by the initial HA concentration and solution pH value. Adsorption depends on chemical interaction at pH values above the PZC (the pH where the Zeta potentials of minerals are zero) of magnetite, while electrostatic attraction and chemical interaction both contribute to the adsorption at pH values below the PZC.