Uranium is obtained from its ores primarily by which broad method, considering real-world hydrometallurgical practice?

Introduction / Context:
Nuclear fuel begins as ores from which uranium must be extracted economically and safely. Recognizing the dominant industrial pathway helps distinguish practical flowsheets from purely academic alternatives.

Given Data / Assumptions:

• Common uranium minerals: uraninite, coffinite, carnotite, etc.
• Ore grades may be low, necessitating selective extraction.
• Goal: produce a concentrate (often called yellowcake) for conversion and enrichment steps.

Concept / Approach:
The primary industrial route is hydrometallurgy: chemical leaching (acidic or alkaline) to dissolve uranium selectively, followed by solid–liquid separation and chemical recovery (e.g., solvent extraction, ion exchange, or precipitation). Physical beneficiation alone rarely suffices for low-grade ores, while direct pyrometallurgy to metallic uranium from ore is not the initial, mainstream approach.

Step-by-Step Solution:
Crush and grind ore to liberate minerals.Leach uranium with sulfuric acid or carbonate systems (depending on gangue).Separate solids from pregnant solution.Recover uranium chemically (e.g., SX/IX) and precipitate as a concentrate.Dry and package yellowcake for conversion/enrichment.

Verification / Alternative check:
Industry case studies and standards describe hydrometallurgical leach plants as the backbone of uranium production, with in-situ recovery (ISR) being a variant that is likewise chemical in nature.

Why Other Options Are Wrong:
Pyrometallurgy directly to metal: not the first industrial step from ore.Physical beneficiation only: insufficient for most uranium ores.Electrometallurgy first: niche, not the mainstream starting point.Fermentation without chemicals: not an established uranium practice.

Common Pitfalls:
Equating “beneficiation” with “extraction” in low-grade ores.Ignoring the strong role of solution chemistry in uranium recovery.

Final Answer:
Chemical method (hydrometallurgical leaching and recovery)