Gold Recovery from Cyanidation Tailings Using Flotation Process

The gold recovery from cyanidation tailings was only 4.01% with the general flotation process, the surface analyses of flotation products were performed, and the results showed that the poor gold recovery with general flotation process was due to the passive films covering the surface of the gold bearing pyrite. These films are mainly hydrophilic hydroxides of Ca, Fe and Mg, at the same time, the depression of CN– to pyrite flotation in the flotation slurry was also a main contributing factor. With the surface repair regeneration procedures, it was proven that sulfuric acid pretreatment plays a dominant role in the removing and cleaning of passive films, while destroying free cyanides in the slurry. Sodium carbonate was then used as a buffering pH modifier and as a slurry dispersant after sulfuric acid pretreatment. The gold recovery was as high as 93.41%, compared to the original gold recovery of 4.01%.

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1. This work was supported by the Natural Science Foundation of China (No. 51474075). The authors thank all the members in the Zijin Mining Group Co., Ltd and the Laboratory of Comprehensive Utilization of Low-Grade Refractory Gold Ores.

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2. Opracowanie rekordu ze środków MNiSW, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2024).