ISME are brilliant guys, the mine is amazing. We were given a tour in the 90's.. They have a salt lagoon with a small boat.
We stayed at a B and B in Carrickfergus, I can't say for sure if its still around. If you want to pm me I will try dig a few suggestions up for you!!!
There are old Iron Mines around Glenariff some of which are still open, and locals drove a series of short levels into the steep cliffs at Kinbane Head, they were digging out a crystallised zeolite called Natrolite, they sold it as 'needlestone' to 19th century tourists.
There are very few other open workings in the North, the Geology is slanted towards the non metalliferous (eg quarrying), obvious exceptions, Cavanacaw Gold prospect etc.
As I said, please pm me soon as poss if you need info, ironically I am off through Northern Ireland on Thursday, however on my way to the Irish Republic. Got a trip down The Lisheen Mine on friday. I will see if I can get some pictures for upload on the site, liven things up a little!!!! 😉