Niobium

Niobium is the chemical element with the symbol Nb and atomic number 41. A rare, soft, grey, ductile transition metal niobium is mainly found in the minerals pyrochlore, the main commercial source for niobium, and columbite. Niobium has physical and chemical properties similar to those of the element tantalum and the two are therefore difficult to distinguish.

Niobium is used mostly in alloys to improve overall quality. For instance a small addition to molten steel acts as a grain refiner, encouraging formation of a micro-structure that adds toughness, corrosion resistance, tensile strength, formability and strength.

Niobium is estimated to be 33rd on the list of the most common elements in the Earth’s crust with 20 ppm. The free element is not found in nature.  Minerals that contain niobium often also contain tantalum in varying amounts. The major sources of niobium are from the following ores/minerals: 

Associated with carbonatites and as a constituent of pyrochlore. In this instance grades are likely to be between 0.6 and 2.5% and may be found as large deposits, Brazil in particular, e.g. Araxa (Brazil) and Catalao (Brazil). Tantalum is not present in commercial quantities.

Columbite-tantalite minerals found as accessory minerals in pegmatite intrusions, and in alkaline intrusive rocks. The Nb2O5/Ta2O5 ratio is normally between 20/1 and 10/1, e.g. Crevier (Canada) and Ghurayyak (Saudi Arabia).

As niobates of calcium, uranium, thorium and the rare earth elements such as pyrochlore ((Na,Ca)2Nb2O6(OH,F)) and euxenite ((Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6). This source may be of significance in the future and in instances where the rare earth elements are of commercial grade and the niobium and tantalum will be mined as by-products, e.g. Thor Lake or Nechalacho (Northwest Territories, Canada) and Strange Lake (Quebec, Canada).

Brazil has over 95% of the world’s known resources of niobium. Canada has the highest resources of the other countries. However there is and the potential to define resources in Nigeria, the DRC, Tanzania, Gabon, Malawi, Australia, Afghanistan, Russia and Colombia.
 

Production

In 2008 world production of niobium, measured in tonne of contained Nb metal was approximately made up as follows:

  • Araxa (Brazil): 51,000 tonne (82.3%)
  • Catalao (Brazil): 5,100 tonne (8.2%)
  • Niobec (Canada): 4,400 tonne (7.1%)
  • China/others: 1,500 tonne (2.4%) 


Uses

Niobium Product
 

Application
 

Technical Attributes/Benefits
 

HSLA FeNb (~60%Nb)



 

Niobium additive to ‘high strength low alloy’steel and stainless steel for oil and gas pipelines, car and truck bodies, architectural requirements, tool steels, ships’hulls, railroad tracks.
 

Imparts a doubling of strength and toughness due to grain refining. Weight reduction.


 

Niobium oxide




 

- Manufacture lithium niobate for surface acoustic wave filters.
- Camera lenses.
- Coating on glass for computer screens.
- Ceramic capacitors.
 

- High index of refraction.
- High dielectric constant.
- Increase light transmittance.


 

Niobium carbide
 

Cutting tool compositions.
 

High temperature deformation, controls grain growth.
 

Niobium powder
 

Niobium capacitors for electronic circuits.
 

High dielectric constant, stability of oxide dielectric.
 

Niobium metal plates, sheets, wire, rod, tubing
 

 

- Sputtering targets.
- Cathode protection systems for large steel structures.
- Chemical processing equipment.

 

Corrosion resistance, formation of oxide and nitride films. Increase in high temperature resistance and corrosion resistance, oxidation resistance, improved creep resistance, reduced erosion at high temperatures.
 

Niobium-titanium alloy
Niobium-tin alloy


 

Superconducting magnetic coils in magnetic resonance imagery (MRI), magnetoencephalography, magnetic levitation transport systems, particle physics experiments.
 

Electrical resistance of alloy wire drops to virtually zero at or below temperature of liquid helium (-268.8°C)


 

Niobium-1% zirconium alloy
 

- Sodium vapor lamps
- Chemical processing equipment
 

Corrosion resistance, fixation of oxygen, resistance to embrittlement.
 

Vacuum-grade ferro-niobium and nickel-niobium
 

Superalloy additions for turbine blade applications in jet engines and land-based turbines. Inconel family of alloys, superalloys.
 

Increase in high temperature resistance and corrosion resistance, oxidation resistance, improved creep resistance, reduced erosion at high temperatures.
 


Markets and Growth

The world demand for niobium in 2008 was approximately 61,000 tonne of contained Nb metal. This was made up as follows: -

            - FeNb for pipe steel: 24%
            - FeNb for automobile steel: 24%
            - FeNb for structural steel: 29%
            - Stainless steel: 10%
            - Other steels and iron: 8%
            - Nb metal and alloys: 5%

In 2009 it is estimated that demand for niobium fell by as much as 20%. In January 2010 the operators of the Araxa mine announced that their production (over 80% of the world total) in 2011 would need to increase to pre-financial crisis levels to satisfy increasing demand. 

According to IAMGOLD, June 2009 it is anticipated that demand for niobium will increase at the rate of 15% per annum in the period 2010-2014 inclusive. This is predominately because of the increased demand for FeNb for HSLA (high strength low alloy) steels made up of a 10% growth in intensity and a 5% growth in steel production. This would extrapolate to a 2014 demand of just less than 100,000 tonne of Nb metal equivalent.