Dissolution Behavior of Niobium Compounds under Alkaline Conditions

Area of Science:

• Materials Science
• Geochemistry
• Chemical Engineering

Background:

• Niobium is a critical element for advanced materials.
• Understanding niobium dissolution is key for efficient hydrometallurgical processing.
• Existing niobium solubility data in alkaline media is limited.

Purpose of the Study:

• Investigate niobic acid and potassium niobate dissolution in KOH solutions.
• Determine the influence of temperature and KOH concentration on niobium solubility.
• Provide data for optimizing niobium extraction and recovery.

Main Methods:

• Polythermal method for dissolution studies.
• Thermodynamic modeling using OLI Studio Stream Analyzer and PHREEQC.
• Aqueous niobium concentration measured by ICP-OES and UV-vis spectroscopy.

Main Results:

• Niobic acid dissolution increases with temperature and decreases with KOH concentration.
• Potassium niobate dissolution shows complex behavior, with phase-dependent preferences.
• Experimental data deviates from predicted values, highlighting data gaps in niobium solubility.

Conclusions:

• Findings advance the understanding of niobium chemistry in alkaline environments.
• Results are crucial for developing efficient hydrometallurgical processing of niobium sources.
• Data supports optimization of leaching, crystallization, and recovery steps.