For those unable to corroborate the theory that production of...

For those unable to corroborate the theory that production of Chinese low-grade vanadium-bearing iron concentrates is decreasing, here is some evidence:

China VTM Mining Interim Report 2018:
https://www.chinavtmmining.com/attachment/2018090716470100033261770_en.pdf

Here are a couple of extracts:

BUSINESS AND OPERATIONS REVIEW:
During the Reporting Period, the Group observed an obvious fast changing trend that there has been a shift in demand for higher grade iron ore (above 62% TFe) from lower-grade iron ore (below 62% TFe) arising mainly from those stringent requirements imposed by the Chinese government in relation to environmental protection and emission control emphasising on sustainable mining practices. Many miners are thus revamping their strategies to adapt to these new fragmented markets which have seen an increasingly higher demand and significant price premium for high-grade iron ore, whereas a sharp fall in both demand and prices for low-grade iron ore. It is highly likely that these market trends will continue under the existing government policies.
As a result of these drastic changes which have fragmented the iron ore markets, for 1H2018, the Group:
(i) recorded a loss for its operating mines of low-grade iron concentrates as a result of (i) significantly lower selling prices (which fell by 16% to 22% on average as compared to 1H2017) due to falling demand and aggressive de-stocking; and (ii) impairment losses due to lower value-in-use given the fall in selling price and lower-than-expected utilisation rates and inactive status of the existing suspended mines which the Group has no commercial grounds to expand or resume production at the Low Fe and Inactive Mines; and in contrary,
(ii) recorded significantly higher gross profit margin, a cash profit and positive operating cash flows for its operating mines of high-grade iron concentrates as a result of higher demand, higher selling prices and focused strategies to improve efficiencies for production of high-grade iron concentrates at the High Fe Mines.

OPERATIONAL AND FINANCIAL OVERVIEW:
During the Reporting Period, the Group reported lower revenue, which fell by 23.3% to approximately RMB548.8 million for 1H2018. The fall in the Group’s revenue for low-grade iron concentrates and trading outpaced those of high-grade iron concentrates resulting in a fall in total revenue for the Group for 1H2018. Specifically,
• selling price for low-grade vanadium-bearing iron concentrates (within the Southern Region, Panzhihua and Panxi region in particular) fell sharply by approximately 16% to 22% on average due to falling demand for cheap low-grade iron ore under the China’s anti-smog policies;
• selling price for high-grade iron concentrates rose by approximately 7% – given the Group’s focused strategies in improving efficiencies for its High Fe Mines, the mine operations located mainly in the Northern Region had been able to constantly produce high-grade iron concentrates within an average range of 65% TFe (with an encouraging but small volume of 72% TFe during 1H2018); and