Which Collectors Work Best for Lithium Ore Flotation?

In spodumene flotation, one of the most critical success factors is the effective activation of the mineral surface. This activation ensures strong collector attachment and stable froth generation, leading to higher lithium recovery rates.

The process generally includes desliming, ore washing, and strong alkali conditioning—all essential for restoring the mineral’s natural surface reactivity.

Surface Contamination During Weathering

During natural weathering of lithium pyroxene ores, the spodumene surface becomes contaminated with trace metal ions such as iron (Fe³⁺), aluminum (Al³⁺), and manganese (Mn²⁺).

These ions promote the formation of fine clay-like coatings that adhere to the mineral grains and interfere with collector adsorption. If not removed, these impurities inhibit the attachment of flotation reagents, reducing recovery efficiency and concentrate grade.

Strong Alkali Conditioning

To resolve this issue, processors typically:

1. Thicken the pulp (concentrate the slurry)
2. Add sodium hydroxide (NaOH)
3. Agitate vigorously for several hours

This strong alkaline conditioning step dissolves or loosens contaminating films, cleans the mineral surfaces, and enhances collector adsorption efficiency during subsequent flotation.

Flotation Conditions and Collectors

During flotation, operators maintain alkaline conditions to keep the spodumene surface active and hydrophobic.

• Fatty acid collectors, such as oleic acid or sodium oleate, are most commonly used and tend to produce effective lithium recoveries.
• In some cases, amine-based collectors may also improve recovery, depending on the ore composition.

However, the collector type, dosage, and pH must always be optimized through systematic laboratory testing, as mineralogical variations among deposits significantly influence flotation behavior.

The combination of desliming, alkali activation, and tailored reagent selection forms the foundation of modern spodumene flotation. When properly implemented, these steps ensure clean mineral surfaces, strong collector attachment, and high-grade lithium concentrates—critical outcomes for sustainable lithium production.