Enhanced flotation of various Au-Cu-Ag ores using zinc/arsenic/pyrite/lead depressants and Eriez column/StackCell high-intensity technologies.

The increasing challenges in floating copper (Cu), gold (Au) and silver (Ag) ores are driven by factors such as rapidly growing demand, the complex mineralogy of modern deposits, and declining ore reserves and ore grades. Low-grade porphyry ores require fine or ultrafine grinding to achieve adequate mineral liberation. Extremely fine Cu, Au and Ag mineral particles (smaller than 10 µm) may be physically encapsulated within sulfide minerals like pyrite or arsenopyrite. However, fine and ultrafine particles (smaller than 20 µm) have low collision efficiency with bubbles, resulting in a loss of valuable minerals to the tailings. Porphyry Cu, Au and Ag ores can contain undesirable penalty elements like arsenic (As), zinc (Zn) and lead (Pb), which are difficult to reject. Selective flotation is required using different reagents and pH conditions for each mineral. This paper investigates the improved flotation performance of five low-grade Cu, Au and Ag ores using Eriez column/StackCell high-intensity technologies and various reagents to minimize final concentrate contents of sphalerite (ZnS), arsenopyrite (FeAsS) and galena (PbS) before incurring a penalty. [ABSTRACT FROM AUTHOR]