Sulfur-isotope distribution and contamination related to the Balya Pb-Zn Mine in Turkey

Sulfur-isotope (δ³⁴S) values and weight (%) of acid-volatile sulfur (AVS), chrome-reducible sulfide (CRS), elemental sulfur (ES), and acid-soluble sulfates were determined in Balya Mine ore rock, mine wastes, and Kocacay River and Lake Manyas sediments. Estimation of isotopic fractionation (Δ³⁴S) between product sulfate and initial CRS (pyrite) was used to evaluate the progress of sulfide oxidation in the mine-waste area. Water- and acid-soluble sulfate produced from different mine-waste samples, such as metallurgical waste (MW) and waste rock (WR), in laboratory experiments also shows distinct δ³⁴S values and allows identification of the acid-mine-drainage sources in the mine-waste area. Average δ³⁴S_SO4values are -1.43‰ for MW (n=4) and +2.06‰ for WR (n=8). Short (24 hr) and long (60 days) term leach experiments were considered using alternating wet/dry conditions to simulate sulfate-production capacity and metal-discharge characteristics for MW and WR piles. Release of heavy metals follows the order of Pb²⁺ >Mn ²⁺ >Zn²⁺ >Cu²⁺ for these pile samples. Values of δ³⁴S_SO4 for river water that was collected after 3-4 h of heavy rainfall are close to values of δ³⁴S _SO4 for water-soluble sulfates from mine-waste piles used in laboratory leach experiments.