Flotation of a mineralized structure to decrease arsenic content in gold concentrate

Arsenic is a penalty element in flotation concentrates, thus decreasing their quality. Consequently, the present investigation is developed with the objective of carrying out the flotation of a mineralized structure to reduce the content of arsenic “As” in the gold concentrate “Au”. For this purpose, sampling was carried out in a vetiform hydrothermal deposit taking 2 kg for Au-As chemical and mineralogical analysis and two flotation tests in a Rougher stage with the same entry conditions, i.e. Au grade equal to 11.46 g/t and As 1.81%. The results indicate that in test 1 the As content in the concentrate was 4.57%, while in test 2 the As grade in the concentrate was 4.86%, considering that in the latter, in addition to the reagents used in test 1, copper sulfate was applied as an activator, where no sulfide depression was evidenced. Finally, it is concluded that with the experimentation developed, the mineral presented a positive response to the flotation process, achieving the expected result with trial 1, also taking into account the dosage of the reagents used.