| Summary: | In this paper, the use of titania functionalised magnetic nanosorbents for rapid removal of arsenic from the alkaline process waters of gold cyanide leaching systems is considered. The Fe3O4@SiO2@TiO2 nanosorbent synthesised via a two-stage hydrolytic process was characterised by scanning electron microscopy - energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), use of a superconducting quantum interference device (SQUID) and Brunauer-Emmett-Teller (BET) specific area methods. Batch adsorption tests showed that both As(III) and As(V) could be adsorbed onto the surface of nanosorbent in around 4 h, with the maximum adsorption capacity of 31.4 mg/g and 10.2 mg/g for As(III) and As(V), respectively, at pH 9. As demonstrated in competitive adsorption tests, the Fe3O4@SiO2@TiO2 nanosorbent performed well in simulated solutions of gold mining process waters with high ionic strengths and complex matrices, presenting a 21.3 mg/g integrated adsorption capacity for As(III) and As(V). The loss in capacity of the Fe3O4@SiO2@TiO2 nanosorbent after four consecutive adsorption-regeneration cycles was less than 40%. On the whole, the good arsenic adsorption capacity, easy preparation and magnetic separability coupled with reusability make it a potentially attractive material for the removal of arsenic from gold cyanidation process waters.
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