Niobium is commonly used to make alloys, and is most important for special steels such as natural gas pipeline materials. Although these alloys do not contain more than 0.1% niobium, a small amount can be added to strengthen the steel. Niobium-containing superalloys are highly stable at high temperatures, making them useful for jet and rocket engines.
Niobium is an alloy component of class II superconductors. These superconductors, which also contain titanium and tin, are widely used as superconducting magnets in MRI scanners. Niobium has low toxicity and is easily colored by anodizing, so it is used in coins and jewelry. Other applications of niobium include welding, nuclear industry, electronics and optics.
1. High temperature alloy
A large part of the world's niobium is used in the production of nickel, chromium and iron based superalloys, either as a pure metal or in the form of high purity niobium-iron and niobium-nickel alloys. These alloys can be used in jet engines, gas turbine engines, rocket assemblies, turbochargers and heat-resistant combustion equipment. Nb will form γ phase in the grain structure of superalloy.
These alloys generally contain up to 6.5% niobium. Inconel718 is one of the niobium-nickel base alloys with the following elements: nickel 50%, chromium 18.6%, iron 18.5%, Niobium 5%, molybdenum 3.1%, titanium 0.9% and aluminum 0.4%. Applications include high end airframe materials, such as those used in the Gemini program.
2. Niobium base alloy
C-103 is a niobium alloy that contains 89% niobium, 10% hafnium, and 1% titanium and can be used in liquid rocket thruster nods, such as the main engines of the Apollo lunar module. The Apollo service module used another niobium alloy. Since niobium begins to oxidize above 400°C, it must be coated with a protective coating to prevent it from becoming brittle.
3. Medical applications
Niobium on surgical medical also occupies an important position, it not only can be used to make medical apparatus and instruments, and it is very good "biological adaptability material", because it has excellent corrosion resistance, not with all kinds of liquid substances in the body, and almost no damage of biological tissue, for any sterilization method can adapt to, So it can be combined with organic tissues for a long time and remain in the body harmlessly.
4. Steel production
Niobium is an excellent additive element in microalloy steel production. Niobium carbide and niobium nitride can be formed by adding niobium to steel structure.
These substances can make the steel grain more fine, slow down the recrystallization process, and enhance the deposition hardening of steel. The steel thus formed has high hardness, strength, malleability and weldability. The content of niobium in microalloyed stainless steel is less than 0.1%. Niobium is used in the production of high-strength, low-alloy steel, which is used in the structural parts of automobiles. Niobium alloys are also used in transport lines.
5. Electrical porcelain
Lithium niobate is an electroferroic substance, which is widely used in the manufacture of mobile phones and optical modulators as well as surface acoustic devices. Its crystal structure belongs to ABO3 and is the same as lithium tantalate and barium titanate. Niobium can replace tantalum in tantalum capacitors, reducing the cost, but tantalum capacitors are still superior.
The estimated abundance of niobium in the Earth's crust is 20 parts per million, the 33rd most abundant of all elements. Some scientists believe that niobium is more abundant throughout the Earth, but is concentrated in the core because of its high density.
Niobium does not occur in its pure state in nature, but is combined with other elements to form minerals. These minerals generally also contain tantalum, such as coltan (niobium, (Fe,Mn)(
Nb,
Ta)2O6) and coltan (Fe,Mn)(Ta,Nb)2O6).
These large niobium deposits occur near carbonate rocks, a type of carbonate and silicate igneous rock, which are also components of pyrochlorite.
Brazil and Canada have the largest deposits of pyrochlorite. The two countries discovered these deposits in the 1950s and are still the largest producers of niobium concentrate. The largest deposit in the world is located in a carbonate intrusion zone in Alassa, Minas Gerais State, Brazil, and belongs to CBMM (Brazilian Mineral Metallurgy Corporation). The other deposit, located at Goias, belongs to Anglo American Resources and is also a carbonate intrusion.
These two mines account for 75 percent of the world's production. The third largest mine, near Saguenay, Quebec, Canada, accounts for 7% of the world's production.
