Froth flotation reagents: xanthates are widely used as which type of reagent in sulfide ore flotation?

Introduction / Context:
Froth flotation relies on selective attachment of certain minerals to air bubbles. Reagents are added to control surface chemistry: collectors, frothers, activators, depressants, and modifiers. Knowing each reagent’s role is fundamental to circuit design and troubleshooting.

Given Data / Assumptions:

• Xanthates are organosulfur compounds, commonly sodium/potassium salts.
• Typical application: sulfide minerals (e.g., PbS, ZnS, CuFeS2).

Concept / Approach:
Collectors selectively render mineral surfaces hydrophobic. Xanthates chemisorb onto sulfide mineral surfaces forming metal–xanthate species, which strongly increase hydrophobicity and bubble attachment probability. Frothers (e.g., pine oil, MIBC) control bubble size and froth stability; activators (e.g., CuSO4) enhance collector adsorption on certain minerals; conditioners/modifiers adjust pH or ionic environment.

Step-by-Step Solution:
Identify xanthate function: hydrophobize sulfide minerals via chemisorption.Map to reagent class: "collector."Therefore, choose "collector."

Verification / Alternative check:
Plant reagent suites list xanthates (e.g., PEX, SEX) under collectors, often blended for selectivity and cost.

Why Other Options Are Wrong:
Frother: controls froth, not hydrophobicity.Activator: enhances adsorption by surface ion exchange, not primary hydrophobization.Conditioner: pH/ionic modifiers, not specific collectors.

Common Pitfalls:
Assuming pine oil is a collector; it is a classic frother. Collectors are typically thiol-based for sulfides.

Final Answer:
collector