When Macri took office in 2015 he abolished export taxes and trade controls. The Financial Post article explains the investment Argentina is making in training up people to take up jobs in the lithium industry. I believe Macri did not want to do this but his hand was forced due to the worsening, even emergency, conditions in Argentina due to the peso's devaluation. They have a pending loan from the IMF for $50 million, perhaps the only way he could get early access to it was to do what he did - cut government costs by eliminating ministries, and imposing export taxes.
I don't think this current tax will be what worries people, it's the uncertainty - if things get worse, what's next? I doubt Macri has changed his long term goal to make Argentina a major lithium exporter, if he does succeed, it could be the thing that pulls the country out of the financial doldrums as worldwide demand for lithium increases.
ORE Price at posting:
$4.16 Sentiment: Hold Disclosure: Held