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Difficulty: HardGeneral Principles of Metallurgy and Metal Extraction

In the froth flotation process used for concentrating low-grade copper sulfide ores such as chalcopyrite (CuFeS2CuFeS_2), pine oil and sodium ethyl xanthate are added to the aqueous suspension of the pulverized ore. What specific roles do pine oil and sodium ethyl xanthate play in this metallurgical separation process?

  1. Pine oil acts as a frothing agent to produce stable foam, while sodium ethyl xanthate acts as a collector to render sulfide mineral particles hydrophobic.Answer
  2. B
    Pine oil acts as a chemical reducing agent to convert copper sulfide into elemental copper, while sodium ethyl xanthate acts as a flux to convert gangue into slag.
  3. C
    Pine oil preferentially dissolves silicate gangue impurities, while sodium ethyl xanthate causes copper ions to precipitate via selective electrolytic discharge.
  4. D
    Pine oil neutralizes amphoteric metal oxides in the matrix, while sodium ethyl xanthate oxidizes the sulfide ions to elemental sulfur.

Answer

Pine oil serves as the frothing agent to generate stable air bubbles, while sodium ethyl xanthate functions as a collector that selectively coats sulfide ore particles to make them hydrophobic.
In froth flotation concentration of sulfide ores, pine oil acts as a frothing agent that creates a stable foam matrix when air is agitated through the ore slurry. Sodium ethyl xanthate serves as a collector reagent; its molecules selectively adsorb onto the surface of sulfide mineral particles, turning them hydrophobic. The water-repellent sulfide particles attach to the rising froth bubbles and are skimmed off at the top, leaving water-wetted silicate gangue behind.

Step-by-Step Solution

1
Identify the purpose of the froth flotation method in metallurgy.
Froth flotation is a physical concentration process used specifically for sulfide ores to separate valuable mineral particles from earthy gangue based on surface wettability.
Sulfide ore particles are naturally or artificially hydrophobic (water-repellent), whereas silicate gangue is hydrophilic (water-attracting).
2
Analyze the function of pine oil in the process.
Pine oil acts as a frother.
It lowers the surface tension of water, enabling the formation of stable oil-coated air bubbles when air is blown into the suspension.
3
Analyze the function of sodium ethyl xanthate in the process.
Sodium ethyl xanthate acts as a collector (polar-nonpolar surfactant).
Its polar group attaches to the sulfide mineral surface while its nonpolar hydrocarbon tail points outward, rendering the mineral particle strongly hydrophobic so it attaches to rising air bubbles.

Key Concept

Froth Flotation Principle and Additive Roles in Ore Concentration
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Topics

General Principles of Metallurgy and Metal Extraction

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