Element transfer by a vapor-gas stream from sulfide mine tailings: from field and laboratory evidence to thermodynamic modeling

Condensates of vapor-gas streams were collected during field and laboratory experiments for the determination of the volatility of chemical elements in sulfide tailings under ambient conditions. The object of research was the Ursk waste heaps (Kemerovo region, Russia). Field experiments were performed on the top of the heap and in neighboring territories; the elements' concentrations in condensates from the top exceed the background values in 2-3 orders of magnitude. To obtain condensates in the laboratory, the waste material was heated to 60 degrees C. Laboratory condensate-contended high concentrations Ca, Mg, but Fe, Cd, Mo, Sn, Zr, and W were lower by more than 2 orders of magnitude. Also, chemical elements such as Au, Zr, Cs, U, and Tl were determined in the laboratory condensates at elevated temperatures. Also, solid samples were leached with water at the laboratory. A high positive correlation of condensate compositions with compositions of water extracts obtained from parallel samples was established. The most mobile elements transferred in the steam-gas phase are alkaline (Li, Cs, Na, K), alkaline earth (Ca, Sr), chalcophile metals (Hg, Zn, Cu), and metalloids (As, Sb, Se). The numerical experiment of metal transfer forms using thermodynamic modeling methods has been performed, including those with organic ligands.

Automated summary

Field and laboratory experiments were conducted to determine the volatility of chemical elements in sulfide tailings. The concentrations of elements in condensates from the top of the heap exceeded background values by 2-3 orders of magnitude. High concentrations of calcium and magnesium were found in laboratory condensates, while other elements like iron and cadmium were lower.