The complete set of equipment for lead-zinc ore washing (commonly referred to as “beneficiation” or “mineral processing”) depends on ore properties (whether oxide or sulfide ore), liberation particle size, and production scale. Currently, over 95% of industrial lead-zinc operations employ flotation. Below is a typical equipment list for a sulfide lead-zinc ore processing plant, covering from crushing to tailings treatment.
I. Crushing and Screening Stage (Preparation before Grinding)
Purpose: To reduce run-of-mine ore to a suitable feed size for the ball mill (typically ≤10–15 mm).
- Feeding equipment: Vibrating feeder (e.g., GZG series).
- Primary crushing: Jaw crusher (PE series), for handling large run-of-mine ore blocks.
- Secondary/tertiary crushing: Cone crusher (multi-cylinder hydraulic cone crusher is most effective) or impact crusher, for secondary reduction.
- Screening equipment: Circular vibrating screen (YK series), for check-screening to ensure qualified particle sizes enter the fine ore bin.
II. Grinding and Classification Stage (Critical before Flotation)
Purpose: To grind the ore to achieve mineral liberation (typically –200 mesh accounting for 60%–80%).
- Grinding equipment: Grid-type or overflow-type ball mill. Common configuration is “one-stage closed-circuit grinding”.
- Classification equipment: Spiral classifier (forming a closed circuit with the ball mill) or hydrocyclone clusters (more efficient for classification, especially recommended for fine grinding).
III. Flotation Separation Stage (Core Process)
Purpose: To sequentially separate lead minerals (galena) and zinc minerals (sphalerite). The principal flowsheet is ”lead preferential flotation, followed by zinc flotation”.
- Conditioning equipment: Conditioner tanks, for thorough mixing of pulp with reagents (lead conditioner tank, zinc conditioner tank).
- Core separation equipment: Flotation machines.
- Lead roughing, scavenging, and cleaning: Commonly use SF type (self-aerating mechanical agitation) in combination with JJF type.
- Zinc roughing, scavenging, and cleaning: Similar setup, but with a different reagent regime.
Note: If the ore contains associated silver, it is typically enriched simultaneously in the lead flotation circuit.
IV. Concentrate Dewatering Stage
Purpose: To reduce concentrate moisture for convenient transport and smelting.
- Thickening equipment: High-efficiency thickeners (lead concentrate thickener, zinc concentrate thickener), to raise pulp density from approximately 30% to 60%–70%.
- Filtration equipment: Ceramic filters or plate-and-frame filter presses. Ceramic filters are currently recommended for lead-zinc concentrates, as they produce clear filtrate and yield dry concentrates with approximately 8%–10% moisture.
V. Tailings Treatment and Environmental Protection (Mandatory Requirement)
- Tailings thickening: High-efficiency deep-cone thickener, to increase tailings density for water recovery.
- Tailings conveying: Slurry pumps + wear-resistant pipelines.
- Auxiliary equipment: Automatic reagent feeders (for precise flotation reagent control), online pH meters, and sampling machines.
VI. Key Selection Considerations (Guidance for Avoiding Pitfalls)
- Sulfide ore vs. Oxide ore:
- The above flowsheet is for sulfide ore. For oxide lead-zinc ores (cerussite, smithsonite), flotation is often ineffective. Instead, gravity concentration (jigs, shaking tables) or sulfidization-xanthate flotation, or even acid leaching, may be required—resulting in vastly different equipment selections. A beneficiation test is mandatory beforehand.
- Matching ball mill and flotation machines: The throughput of the ball mill must be matched to the total volume of flotation cells. A general rule of thumb is that “flotation volume should be 4–6 times the ball mill’s hourly throughput.”
- Higher cost does not always mean better: For ores with low hardness and a tendency to slime, a rod mill may be preferable to a ball mill to avoid over-grinding, which can negatively affect flotation performance.
Post time: Jun-24-2026
