TURK 2025

Cyanide leaching remains the primary method for gold extraction from ores in both traditional processing technologies and in-situ mining. During the implementation of this process at the Kumtor Gold Processing Plant, significant volumes of raw industrial wastewater are generated without prior treatment. Given these circumstances, specific characteristics of the model raw industrial wastewater were analyzed based on the annual report data (2012–2026) of the enterprise, including major and trace components, metals, nutrients, and hydrocarbons at various temperatures. Based on wastewater parameters, the permissible discharge limits (PDL) were calculated.
A physicochemical model was developed, and thermodynamic parameters were calculated at the minimum of the isobaric-isothermal potential over a wide temperature range (273.15–303.15 K). As a result, the concentration distribution of components and particles in the aqueous solution was obtained: (Al(SO4)2-, Al³⁺, AlF₂⁺, AlOH²⁺, AlSO₄⁺, AsSO₄³⁻, CO₃²⁻, Ca²⁺, CaCl⁺, CaHCO₃⁺, CaOH⁺, Cl⁻, Co²⁺, CrO₂⁻, CrO₃³⁻, Cu⁺, F⁻, Fe²⁺, FeCl⁺, H₂AsO₄⁻, H₂CO₃, H₃SiO₃⁺, H₄MnO₄²⁻, HAsO₄²⁻, HCO₃⁻, HPbO₂⁻, HSO₄⁻, K⁺, KCO₃⁻, KSO₄⁻, Mg²⁺, MgCl⁺, MgHCO₃⁺, Mn²⁺, NH₄⁺, Na⁺, NaCO₃⁻, NaSO₄⁻, Ni²⁺, NiCl⁺, Pb²⁺, SO₄²⁻, Zn²⁺, ZnCl⁺, AsO₂⁻, Ba²⁺, BaCl⁺, Be²⁺, Cd²⁺, CdCl⁺, Cu⁺, HMnO₂⁻, HMoO₄⁻, SCN⁻, SbO₂⁻, V³⁺, CO₂, OH⁻, H⁺, H₂O). In the solid phase, the distribution included Co, Cu, Hg, Ni, Pb, Se, and Ag, while in the gas phase, it included CO₂, CN⁻, CN, CN⁺, (CN)₂, N₂, NO₂, and O₂.
The calculated parameters corresponded to the operating conditions of the plant in a mountainous environment. The adequacy of the developed physicochemical model and the calculated data was validated against the experimental parameters of raw industrial wastewater. The physicochemical (density, mass, volume), thermodynamic (enthalpy, entropy, heat capacity, internal energy), and phase (liquid, solid, gas) characteristics of this complex, multicomponent heterogeneous aqueous-saline system are valuable for predicting practical approaches to mixing different wastewater streams, particularly raw industrial and domestic wastewater at the facility.