How Is Copper-Molybdenum Ore Separated by Flotation?

Jessica

Lead Automation & Intelligent Mining Systems

+8617887940518

2026-09-12

How Is Copper-Molybdenum Ore Separated by Flotation?

Copper-molybdenum ores are often processed together because both minerals can float well under similar conditions. The challenge is to recover copper and molybdenum efficiently while producing a clean molybdenum concentrate. Flotation is the main method used for this separation.

Why Copper and Molybdenum Need to Be Separated

Copper and molybdenum commonly occur in the same sulfide ore, especially in porphyry deposits. During initial flotation, they may both report to the same bulk concentrate. Since molybdenum is usually sold as a higher-value separate product, it must be separated from copper afterward.

The Typical Flotation Process

The process usually begins with grinding the ore to liberate the valuable minerals. Then the ore pulp is conditioned with reagents and subjected to bulk flotation, where both copper and molybdenum are collected together.

After that, the concentrate undergoes separation flotation. In this stage, molybdenum is floated while copper is depressed, or sometimes the reverse is done depending on the plant design.

How Copper Is Depressed

To separate molybdenum from copper, copper minerals are usually depressed using reagents such as sodium hydrosulfide, sodium sulfide, or lime. These reagents reduce the floatability of copper sulfides, allowing molybdenite (MoS₂) to float more selectively.

In many circuits, modifiers and pH control are also used to improve selectivity.

How Molybdenum Is Floated

Molybdenite has natural hydrophobicity, which makes it easy to float. Once copper is depressed, collectors like hydrocarbon oils may be added to enhance molybdenum recovery. Frothers help form a stable froth layer so the molybdenum-rich particles can be collected.

Common Separation Methods

There are two main approaches:

• Bulk flotation followed by copper-molybdenum separation
• Differential flotation directly from the ore, if mineralogy allows

The bulk flotation method is more common because it is more flexible and usually gives better recovery.

Key Factors Affecting Separation

Several factors influence the success of flotation separation:

• Ore mineralogy and liberation size
• Reagent type and dosage
• pH level
• Grinding fineness
• Water chemistry
• Degree of oxidation of copper minerals

Even small changes in these factors can affect concentrate grade and recovery.

Final Product

The result is usually two products:

• Copper concentrate for smelting
• Molybdenum concentrate for further refining

Proper flotation separation improves both product value and overall plant efficiency.

Conclusion

Copper-molybdenum ore separation by flotation relies on selective reagent use, careful pH control, and the natural floatability of molybdenite. By depressing copper and floating molybdenum, plants can produce high-quality separate concentrates with good recovery.

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