In the beneficiation of sulphide ores (e.g., copper, lead, zinc), which process has virtually no alternative for effective separation under most industrial conditions?

Introduction / Context:
Sulphide minerals possess surface chemistry amenable to selective attachment of air bubbles using collectors, frothers, and modifiers—making flotation the primary enrichment route worldwide.

Given Data / Assumptions:

• Sulphide ore feed with fine liberation sizes.
• Need for selective separation among multiple sulphide minerals.

Concept / Approach:
Froth flotation exploits differential hydrophobicity, allowing selective recovery by tuning reagents and pH. Gravity methods (tabling, jigging, heavy media) are ineffective at fine sizes and small density contrasts common in sulphides. Classification is only a sizing step, not an upgrading process.

Step-by-Step Solution:
Identify sulphide system requiring surface-selective separation.Select froth flotation as the only broadly viable method.

Verification / Alternative check:
Industrial concentrators universally use flotation circuits for sulphide ores, confirming this choice.

Why Other Options Are Wrong:
Gravity and classification lack selectivity/efficiency at fine sizes.

Common Pitfalls:
Overestimating gravity methods for fine, complex sulphides.

Final Answer:
Froth flotation