Another error at 2:25, the mine produces zinc concentrate (zinc sulphide mainly) which is sent abroad to smelters who produce the zinc metal. The mine at Navan does not produce metal.
The "history" told at 1:40 is incorrect! The agricultural survey showed high copper values, which do not seem to have had any connection to the zinc deposit. A major international mining company found high levels of zinc (up to 2.5% in soil samples), and decided it was contamination from metal sheds and dropped the licence. Tara Exploration then took out the licence and investigated on the ground, finding ore-grade zinc mineralisation in boulders propping up electricity posts. The rest is as they say, history.
Back in 1974, a famous Labour politician stood on a chair at a public meeting to tell us (I was there) that the Navan mine would be "a hole in the ground of no value to the community or the nation". So, misinformation comes out of the mouths of politicians too!