I. Mechanism of Action
1.Removal of Collector Coatings: Sodium sulfide (Na₂S) exhibits strong adsorption properties, effectively desorbing xanthate-type collectors from mineral surfaces. This disrupts the bond between collectors and minerals, achieving depressant removal.
2.Inhibition of Residual Effects: Post-removal, residual sodium sulfide must be eliminated through thickening and washing to prevent its inhibitory effects on subsequent sulfide mineral flotation.
II. Application Process
1.Slurry Thickening: Mixed concentrates are first dewatered using thickeners or hydrocyclones to reduce reagent concentrations in the slurry.
2.Sodium Sulfide Addition: Excess sodium sulfide is introduced (typically in large doses) to promote collector desorption from mineral surfaces.
3.Washing and Pulp Conditioning: Post-removal, the slurry is filtered, rinsed with water, and reconditioned for subsequent separation flotation.
III. Key Considerations
1.Dosage Control: Precise dosing is critical. Insufficient sodium sulfide leads to incomplete removal, while excess amounts may inhibit target mineral flotation.
2.Oxidation Issues: Sodium sulfide is prone to oxidation and deactivation, particularly in high-oxidation environments (e.g., Cu-Mo separation), necessitating higher dosages.
3.Process Complexity: Requires integration with thickening, washing, and other steps, making the workflow more intricate compared to mechanical removal methods.
IV. Representative Case Studies
1.Cu-Pb/Zn Mixed Concentrate Separation: Sodium sulfide removes collector coatings, enabling effective separation of copper, lead, and zinc.
2.Cu-Mo Mixed Concentrate Treatment: Sodium sulfide suppresses copper minerals to prioritize molybdenite flotation, often combined with thickening and multi-stage washing for optimal separation.
As a chemical depressant remover, sodium sulfide offers efficiency and specificity in mixed concentrate separation. However, operational parameters must be optimized based on mineral characteristics and process conditions.
Post time: Apr-29-2025
