Producers,unlike an OPEC model,employ a cut their own throat model via their unbelievable greed to try to capture a larger market share, but many prognosticators have ignored the following- China is by far the largest producer also,but very low ore % -average 15% and falling,which suggests they are running out of economical ore- only have 8% of world reserves,unlike many other resources

thus articles repeatedly note Chinese marginal domestic costs of 120-180, e.g 12-13-10 agmetalminer 150,and more recent 120-180, which,absent short term manipulations, provides a floor to prices as those articles note
last I looked Chinese production was ca 500 million tons? so if that pro falls it allows much greater seaborne trade without a precipitous price fall

"Chinese iron ore miners will suffer the most damage as prices retreat and new supply come on stream. Most Chinese iron ore mines are small – less than a million tonnes per year   – and marginal costs within the industry are north of $140.

$120 a tonne has become something of a rule of thumb among iron ore producers – when prices stay below this level for long enough high cost mines, particularly those in China, become unprofitable leading to cuts in supply and a rebound in the price.

This dynamic will remain at work in the iron ore market through 2020, but with so much new capacity that rule of thumb may now have to be adjusted lower."