Beneficiation Technology for Oxide Lead-Zinc Ore

Oxide lead-zinc ore has a complex mineral composition, fine particle size, and high content of slime and soluble salts, making it significantly more difficult to beneficiate than sulfide ores. This article reviews six mature beneficiation processes to help improve the beneficiation efficiency and overall profitability of oxide lead-zinc ore.

Sulfide-Xanthate Flotation is a widely used basic process. Adding sodium sulfide generates a sulfide film on the surface of oxide lead-zinc ore, which, combined with copper sulfate activation and xanthate collectors, achieves separation. Sodium sulfide can simultaneously control the pH of the pulp and disperse slime, but the dosage must be precisely controlled; excessive dosage will inhibit mineral flotation. This process is more suitable for oxide lead-zinc ores with simple compositions and high grades.

Sulfide-Amine Salt Flotation: The principle of sulfide modification is the same as the former, the core difference being the use of amine collectors. Slime and soluble salts can severely interfere with separation indicators. A desliming process is often added to optimize the process during production. This is suitable for oxide lead-zinc ores with a relatively low degree of slime formation.

Sulfide-Amine Salt Flotation: The principle of sulfide modification is the same as the former, the core difference being the use of amine collectors. Slime and soluble salts can severely interfere with separation indicators. A desliming process is often used in conjunction with this process to optimize the flow. This method is suitable for oxide lead-zinc ores with a relatively low degree of slime formation. Fatty acid collector flotation can directly separate zinc oxide and can also be used for reverse flotation for quality improvement. The process involves first floating lead minerals to suppress silicate gangue, and then recovering zinc oxide using fatty acids. It is suitable for ores with low iron, carbonate, and sulfate gangue content.

Chlorinating agent flotation relies on chelating agents to form stable complexes with lead and zinc oxides, achieving efficient separation of minerals and gangue. It can operate at room temperature and natural pH, and is particularly effective for separating smithsonite and cerussite.

Flocculation flotation specifically addresses the challenge of recovering fine-particle zinc oxide. Selective flocculants agglomerate fine minerals, improving the difficulty of floating fine mud and effectively increasing the overall metal recovery rate.

Gravity separation relies on mineral density differences and is more suitable for lead oxide minerals. Under the action of water and air flow, it separates light gangue and enriches high-density lead oxide minerals such as alum and manganese pyrite. It is often used as an auxiliary pretreatment process in conjunction with flotation.