Reagents in froth flotation (pine oil, cresylic acid)\nIn froth flotation of minerals, pine oil and cresylic acid are commonly used as which type of reagent?

Introduction / Context:
Froth flotation separates minerals via surface chemistry. Reagents fall into functional classes: collectors (render target mineral hydrophobic), frothers (stabilize froth), depressants (prevent undesirable minerals from floating), and modifiers/conditioners (adjust pH or dispersion). Knowing which reagent does what is foundational to circuit design and troubleshooting.

Given Data / Assumptions:

• Standard sulfide and oxide flotation practice is implied.
• Pine oil and cresylic acid are classical frothing agents.

Concept / Approach:
Frothers, such as pine oil and cresylic acid (a phenolic mixture), reduce bubble coalescence and produce a stable froth with small, persistent bubbles, enhancing the transport of hydrophobic particles to the froth phase. Collectors (e.g., xanthates) change the mineral surface; depressants (e.g., sodium cyanide, starch) inhibit unwanted flotation; conditioners (e.g., lime, sodium silicate) adjust slurry chemistry. The listed reagents do not act primarily as collectors or depressants but as froth stabilizers.

Step-by-Step Solution:

Verification / Alternative check:
Reagent handbooks classify these substances under frothers; plant dosing systems often label the same storage as “frother tank.”

Why Other Options Are Wrong:

• Collectors change surface hydrophobicity; not the role here.
• Depressants inhibit flotation of gangue; not applicable.
• Conditioners modify pH/dispersion; not the primary function of these oils.

Common Pitfalls:
Confusing commercial blend names that include frothers with collectors; always check MSDS and function.

Final Answer:
Frother