South America | Brazilian Tantalum-Niobium Ore Dressing Technology and Process
1. Introduction Tantalum (Ta) and niobium (Nb) are important rare metals, widely used in electronics, aerospace, medical and energy fields. Brazil is one of the world's important tantalum-niobium ore resource countries, and its ore types mainly include tantalite-niobium iron ore ((Fe,Mn)(Ta,Nb)₂O₆), pyrochlore ((Na,Ca)₂Nb₂O₆(OH,F)), etc. Due to the high density of tantalum-niobium minerals, fine embedded particle size and frequent symbiosis with cassiterite, quartz, feldspar, mica and other minerals, the beneficiation process needs to be combined with the properties of the ore to adopt gravity separation, magnetic separation, flotation and combined processes. This article reviews the beneficiation process of Brazilian tantalum-niobium ore to provide a reference for efficient resource recovery.
2. Ore properties The main characteristics of Brazilian tantalum-niobium ore include: Mineral composition: mainly tantalum iron ore, niobium iron ore, pyrochlore, and associated minerals include cassiterite, quartz, feldspar, mica, tourmaline, pyrite, etc. Embedding characteristics: Tantalum-niobium minerals are mostly fine-grained or micro-grained (0.01~0.5mm), and some are closely associated with cassiterite and iron minerals. Physical properties: Tantalum-niobium minerals have a high density (5.2~8.0 g/cm³), weak to medium magnetism, and medium floatability.
3. Ore dressing process According to the properties of the ore, the beneficiation of Brazilian tantalum-niobium ore usually adopts the "gravity separation-magnetic separation-flotation" combined process. The specific process is as follows: (1) Crushing and grinding The raw ore is coarsely crushed to -25mm by a jaw crusher + cone crusher, and then finely ground to -0.5mm by a ball mill or high-pressure roller mill to ensure the dissociation of tantalum-niobium mineral monomers. (2) Gravity separation and pre-enrichment Due to the high density of tantalum-niobium minerals, gravity separation equipment such as shaking tables, spiral chutes, and centrifugal concentrators are widely used in the roughing stage, which can discard a large amount of low-density gangue minerals and improve the grade of the selected minerals. (3) Magnetic separation Tantalum-niobium minerals have weak magnetism. Weak magnetic separation (iron removal) → medium-strong magnetic separation (enrichment of tantalum-niobium) process can be used to separate magnetic minerals (such as magnetite, ilmenite) and non-magnetic minerals (such as quartz, feldspar).
Spiral Chute
Shaking Table
4) Flotation concentration For fine-grained tantalum-niobium ores, the gravity separation recovery rate is low, and the flotation process can be used: Adjuster: NaOH or Na₂CO₃ adjusts the pH to 8~9. Inhibitor: Water glass inhibits silicate minerals. Collector: Fatty acids (such as oleic acid) or phosphonic acids (such as styrenephosphonic acid) selectively collect tantalum-niobium minerals.
Flotation Cell
(5) Electrostatic separation or chemical purification (optional) When high-purity tantalum-niobium concentrate is required, high-pressure electrostatic separation or acid leaching (HF+H₂SO₄) can be used to further remove impurities.
Conclusion The beneficiation of Brazilian tantalum-niobium ore is mainly based on the combined process of "gravity separation-magnetic separation-flotation". Optimizing the process for different ore properties can significantly improve the recovery rate. In the future, the development of efficient separation equipment and green beneficiation technology will further promote the sustainable utilization of tantalum-niobium resources. (Note: The actual beneficiation process needs to be determined based on the specific ore property test.)
Three discs magnetic separator
Electromagnetic separator
