Supplementary data for "Intrinsic Alkalinity of a High-Na2O–SO3 Secondary Lead Slag from the Uzbekistan Non-Ferrous Metal Scrap Processing Plant: A Liability for Environmental Assessment and an Asset for Selective Lead Recovery"

Supplementary data for the manuscript submitted to the Journal of Sustainable Metallurgy (manuscript SUME-D-26-00697). This archive contains the geochemical modelling inputs and derived data underlying the study. All results generated from these files are thermodynamic equilibrium predictions. They have not been validated by independent phase identification (XRD, SEM) or by bench-scale leaching. The normative phase inventory used as the input to every simulation is an operational, stoichiometrically constrained allocation derived from a single bulk XRF measurement, not a measured mineralogy. CONTENTS PHREEQC_Input_Files/ — seven PHREEQC v3.8.6 input files: S1A, S1B, S1C — water-contact leaching at L/S = 10 L/kg, with the charge-unbalanced sodium fraction speciated as hydroxide, bicarbonate and metasilicate respectively (pitzer.dat) S2 — corrected TCLP simulation, EPA Method 1311 (pitzer.dat) S3 — SPLP simulation, EPA Method 1312 (pitzer.dat) S6 — Tier-2 lead speciation (phreeqc.dat) S7 — complete 20-run face-centred central-composite design, alpha = 1.0 (phreeqc.dat) Acetate_SOLUTION_SPECIES_custom_block.txt — custom acetate speciation block (pKa = 4.757) required for the TCLP simulation, absent from the standard PHREEQC databases README.txt — full description of each file, run instructions, and a note on the units used in the tabulated responses CCD_design_matrix.csv — the 20 design points with their simulated Pb and Fe responsesNormative_allocation.csv — stoichiometric allocation of the oxide-mode XRF analysis to normative phases, giving an intrinsic alkalinity of 1.577 mol per kg of slagSupplementary_Material.docx — the full supplementary document accompanying the manuscript Software: PHREEQC v3.8.6 (build 17100), U.S. Geological Survey. Please read README.txt before running the input files; it documents the database required for each simulation and the basis on which the tabulated responses are reported.