1,200 t/d Lead-Zinc Flotation Plant — Morocco

Background

This profile represents a typical 1,200 t/d lead-zinc operation in Morocco, part of Xinhai’s North African and Mediterranean market. The ore was a sulfide lead-zinc ore in which galena (lead) and sphalerite (zinc) occur together, so the plant had to produce two separate saleable concentrates rather than a bulk product. Clean separation of lead from zinc, with controlled cross-contamination, was the central metallurgical challenge.

Solution

Testwork established the grind size for mineral liberation and the reagent scheme for differential flotation, the standard route for polymetallic sulfides. After crushing and closed-circuit grinding with a wet ball mill, the pulp first floats galena while sphalerite is depressed with zinc sulfate and other depressants. The lead-depleted pulp is then reactivated with copper sulfate and the zinc is floated in a second stage. Both circuits use JJF flotation cells in a rougher-cleaner arrangement, with regrinding of rougher concentrates to reach saleable grade. Each concentrate is thickened and dewatered on a filter press for shipment, and tailings water is recovered.

Delivered as EPC+M+O, the project covered ore testing, in-house manufacturing, construction, commissioning and operator training. The decisive work was the reagent scheme: selective depression and reactivation are what keep zinc out of the lead concentrate and lead out of the zinc concentrate, which is the difference between two saleable products and a downgraded mixed concentrate. The lead circuit ran at controlled pH with zinc sulfate to depress sphalerite, while the zinc circuit used copper sulfate to activate it and lime to depress pyrite. Each rougher concentrate was reground to liberate locked grains before cleaning, which lifted both concentrate grades and reduced misplaced metal between the two products.

Outcome

Differential flotation on a sulfide lead-zinc ore typically recovers around 85-92% of each metal into its own concentrate, with grades tuned in the cleaning stages and cross-contamination controlled by the depressant regime. Producing separate Pb and Zn concentrates improved the payable value of the ore versus a bulk product. These are representative ranges, not guarantees; actual results depend on mineralogy, liberation and reagent control.

For the full flowsheet logic see the lead-zinc processing solution and the flotation equipment range. To size a lead-zinc plant to your ore, contact us for an ore test.