Xanthate degradation in aqueous and pulp systems: Temperature-pH-metal ion controls, mechanisms, and treatment strategies

• Temperature, pH, and metals jointly control xanthate degradation pathways. • pH-dependent HX/X − speciation governs rates, branching, and CS 2 release. • Cu 2+ and Fe 3+ form condensed reservoirs that regulate gas evolution. • Mineral surfaces redistribute xanthate, invalidating single-pool kinetics. • MIxanD checklist standardizes reporting and enables transferable modeling. Xanthates are indispensable collectors in sulfide flotation but are chemically unstable in process water, where they partition into gaseous (CS 2 /COS), condensed (dixanthogen and metal-xanthates), and aqueous oxy-sulfur species. This review integrates clean-solution kinetics, ore-pulp reactor studies with three-phase mass balances, and treatment technologies to establish temperature, pH, and dissolved metals as practical control conditions governing xanthate fate. In homogeneous solutions, alkyl xanthates commonly exhibit apparent first-order Arrhenius kinetics, with rate constants increasing by approximately one order of magnitude between 25 and 50 °C and by over two orders of magnitude at higher temperatures. Solution pH dictates HX ↔ X − speciation and reaction branching: acidic conditions promote rapid degradation with a pronounced CS 2 maximum near pH ≈ 2.2; a relative stability window at pH 7–8; whereas alkaline behavior remains highly sensitive to buffer chemistry. Dissolved metals strongly redirect degradation fluxes through condensed reservoirs that regulate gas evolution. Cu 2+ preferentially sequesters xanthate as CuX/CuX 2 and/or X 2 , markedly suppressing CS 2 release, while Fe 3+ accelerates degradation, that can drive deeper oxidation toward sulfate. In ore pulps, mineral surfaces further redistribute xanthate into adsorbed and precipitated pools, attenuating headspace CS 2 and invalidating simple single-pool kinetics. Based on these insights, we propose operational control windows together with a Minimal Information for Xanthate Degradation (MIxanD) checklist and validated headspace-CS 2 workflows to standardize reporting, diagnose recycle-water effects, and enable transferable multi-pool reaction-transport modeling.