RE: Great news for vanadium16 Jan 2019 09:29
BBN - I had a discussion with Richken yesterday regarding Niobium substitution. It is not a trivial thing to do. Here's a good summary from an industry insider, and I'm not just talking about any old analysts here:-
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Vanadium and niobium impart higher strength in carbon steels through very different metallurgical processes. Vanadium has high solubility in carbon steel and stays in solution while the steel is being rolled, only precipitating as a carbide or carbonitride after the steel is rolled and on the cooling table. The precipitation results in increased strength primarily through precipitation hardening but also as a result of grain refinement that occurs due the presence of the precipitates. Increased strength is not process related but rather linear to the vanadium content of the steel
Niobium has low solubility in carbon steel and this feature is used to produce fine grain steel where the majority of the increased strength is due to grain refinement. Nb precipitate during the TMCP rolling process causing fine grain steel to be produced. The strengthening effect is primarily due to grain refinement and is process dependent.
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The mill processing requirements for Niobium are much higher - you need a reheat furnace that goes up to 1200 deg C. Most bar mills have a reheat furnace that only goes to 1050 deg C.
Also for the Niobium process you need a high power rolling mill that can produce a minimum of 50% reduction in cross section on each pass through the rollers (this is a big difference from Vanadium).
The final thing for me is that 90% of the world's Niobium comes from a single mine in Brazil - if I was a steel mill owner I would be very wary about going to lots of trouble to introduce a new process and spend money on new processing equipment if that relied entirely on a single mine outside of my control. Fine maybe I'd consider it if I already had the equipment sitting around and staff that knew how to run these different processes, but if not, then no chance - I and every other mill owner will just have to just suck up the extra cost of Vanadium, like we would if it was an increase in the price of iron ore, or energy.