Those who would like to know more about rebar standards in China and in general should have a look here. The first link is to a presentation by CBMM (the world's largest niobium supplier) and is hence bias towards the substitution of niobium for vanadium, but the information is still helpful when getting a grip on the situation. Vanadium has been preferred to niobium by Chinese producers, firstly because of their domestic supply and secondly due to better resulting properties of the rebar per unit of consumption. However, price does come into it and there has been an increase in niobium shipments from Brazil to China for this reason. Take a look:
https://bit.ly/2UjcO9M
Further to this, I attach the translated rebar standards:
https://bit.ly/2KiEuqG
To me, the very fact that China are having to look outside their own resources to source raw materials, something that they actively look to avoid where possible, is a very positive sign that the market dynamics are changing. Demand, as can be inferred from the rebar standards, is seeing a real uptick (the price spike was due to the demand shock of the new standards being imposed and steel mills quickly restocking, before being given a tolerance period as the strict enforcement of those standards was put off until more favourable margins were available across the Chinese steel industry). Rest assured that the tolerance period should end in the reasonably near term. This tolerance period, alongside some substitution and de-stocking, is commonly believed to be the reason for the recent downward pressure on the vanadium price. On the supply side, low grade Chinese vanadium-bearing iron ore mines are being closed as local governments look to clean up the country. Steel mills, whose economics aren't dependent on vanadium output (from slag), continue to prefer high grade seaborne supply where the price and availability allows. Therefore, supply is expected to remain constrained from these Chinese co-product sources, which currently account for roughly 60% of global vanadium supply.
(20min delay)