Effects of binders on balling behaviors of iron ore concentrates

An organic binder, Funa, has been developed and used in the production of iron ore pellets for direct reduction in China. This paper mainly describes the effects of the binder on balling behaviors of magnetite concentrates as compared to bentonite binder. Natural ballability and dynamic ballability of concentrates as well as the mechanical strengths of the balls have been included in the assessment. Results show that the organic binder markedly improved the natural ballability and the mechanical strengths but reduce the balling rate compared to bentonite. Investigation shows that the improvement in natural ballability by the binder is attributed to its increasing effect on the wettability on the surface of concentrates. Due to its effects of increasing liquid viscosity, however, the binder clearly reduced the balling rate of the concentrates. The binder clearly improved wet ball strength also due to its viscosity increasing effects, as well as its chemical bonding to the iron ore surface. High‐strength solid bridging of the binder and chemical bonding are the main reasons for much greater strengths of dry balls.