PHREEQC simulation dataset for the SO4/Ca sensitivity study of Atacama-type lithium brines

This dataset contains the complete reproducibility package for the manuscript: "The calcium-sulfate geochemical divide as a process-optimization criterion for lithium-brine evaporation: PHREEQC sensitivity analysis of the sulfate-to-calcium molar ratio in Atacama-type brines"(Tabilo, Calisaya & Toro, submitted to Hydrometallurgy, 2026). The archive provides: (1) The custom extended thermodynamic database pitzer_lithium_v2.dat, built on top of the standard PHREEQC pitzer.dat (Harvie-Moller-Weare 1984 parameterisation) and augmented with Li+-Cl- binary parameters from Lassin et al. (2015), Li+-SO4(2-) ternary mixing parameters from Song & Yao (2004), and two added Li-bearing solid phases (Li2SO4.H2O, log Ksp = -2.623; Lithium_Carnallite LiCl.MgCl2.7H2O, log Ksp = 7.51). (2) The Python driver (simulate.py + config.py) that builds PHREEQC input decks, executes the simulations, and parses outputs. (3) The analysis pipeline (analysis.py) that generates all paper figures and summary tables from the parsed outputs. (4) Raw simulation outputs for the 10 SO4/Ca ratios analysed (R = 0.2, 0.5, 0.8, 1.0, 1.2, 1.5, 2.0, 3.0, 4.0, 5.0), the comparative Uyuni-brine simulation, and the three industrial-anchor scenarios reported in Figure 7 (R = 0.5, 1.001 = SQM target, 5.0). (5) Publication-quality TIFF figures (Figures 1-7) at 300+ dpi. All simulations were performed with PHREEQC 3.8.6-17100 at 25 C and 1 atm via 200 incremental REACTION steps from initial solvent mass 1.000 kg down to 0.050 kg (CFmax = 20x). Quantitative analysis in the paper is restricted to CF <= 10-12x, where ionic strength remains within the validated Pitzer domain (IS <= 13 mol/L); data beyond this range are provided for diagnostic continuity only. To reproduce all figures from scratch, run "python analysis.py --rerun" inside the code/ folder (requires PHREEQC 3.8.6 in PATH plus Python >= 3.9 with pandas, numpy, matplotlib, Pillow). v1.0.1 (2026-05-28): Adds Camino B phase-disabling sensitivity battery (Appendix A of the manuscript). New scripts analysis_2.py and analysis_3.py, new documentation DIAGNOSTIC_FINDINGS.md, 10 new CSV simulation outputs, and 3 new figures. The body figures of the paper (Figs 1-7) are unchanged in methodology; only Figure_6.tif was re-rendered to remove Ogawa anchor markers, which are now treated systematically in Appendix A.