Abstract:Pretreatment of high content of Si- and Al-containing cyanide tailings by water leaching to remove some impurities, such as the major impurities minerals of Si and Al, as well as its effect on Fe extraction in the water leaching process was investigated. The effects of different parameters on iron recovery were studied, and the reaction parameters were proposed as follows: sodium carbonate content of 30%, water leaching at 60 °C for 5 min, liquid/solid ratio of 15:1, and exciting current of 2 A. Under these optimal conditions, magnetic concentrate containing 59.11% total iron and a total iron recovery rate of 76.12% was obtained. In addition, the microstructure and phase transformation of the process of water leaching were studied by X-ray powder diffraction technique (XRD), Electronic image of backscattering (BEI), X-ray fluorescence (XRF), and energy dispersive spectrometry (EDS). The results indicate that the soluble compound impurities generated in the roasting process are washed out, and the dissoluble substances enter into nonmagnetic materials by water leaching, realizing the effective separation of impurities and Fe.

Key words: water leaching; cyanide tailings; grade of magnetic concentrate; recovery rate of iron; yield of magnetic concentrate