Reagents in froth flotation (pine oil, cresylic acid) In froth flotation of minerals, pine oil and cresylic acid are commonly used as which type of reagent?
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AFrother
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BCollector
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CDepressor
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DConditioner
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EFlocculant
Answer
Correct Answer: Frother
Explanation
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:
Identify reagent function: pine oil/cresylic acid → froth stability and bubble size control.Map to reagent class → frothers.Select “Frother.”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