Development in selective flotation of galena from lead-zinc-iron sulfide ores in China

A new technique for the flotation separation of lead zinc iron sulfide ores has been developed and applied to several mills in China. It is characterized by the matching of relationships among pulp pH, pulp potential, flotation collector inside grinding mill. The flotation separation of galena and sphalerite has been accomplished without the addition of any conventional depressant of sphalerite such as zinc sulphate. Lime is used as a regulator and stabilizer of pulp pH and potential. Diethyldithiocarbamate (DDTC), not xanthate, is determined as a collector for the selective flotation of galena from the Pb Zn Fe sulfide ores. The laboratory scale tests, the plant scale tests and the plant operations have all shown that the best separation results can be achieved at pH of 12.4～12.6, the pulp potential of 160～180 mV. The operation practice in the four plants has confirmed that compared with conventional flotation flowsheet, our new technology can greatly improve the flotation results, reduce the flotation time and the number of flotation cell, and increase the stability of operation and the adaptability to changes in ore properties. All these advantages have made this four plants more profitable.