Finding and Mining Bezdnacine

I’ve seen Talassonite and Rakovene appear around minor and major Triglavian conduits, respectively, and the rocks stay after the conduit in question is closed. What I’d like to know is how I should go about mining Bezdnacine, which only appears at World Ark proving grounds. The one time I managed to get a Procurer in the same system as an Ark, the rocks disappeared before I could mine any!

How do I get access to mineable Bezdnacine without being shot at by Triglavian ships?

Spider tank miners with tanks?

Not the barges themselves, but a pair of Porpoise could be fitted to spider and keep procurers alive. One of them is fitted with mining bursts, and the other with shield bursts.

For a true spider tank, you’d need to use mining frigates with their auxiliary highs. A combination of ventures or bursts.

For the soloist - mining barges do not readily themselves to active tanks and kiting damage. You would looking at a Prospect for that style.

Orca also a viable choice. As both they and Porpoises can put out decent drone dps. So can proc obviously.

What happens to the rocks after the World Ark disappears anyway? Do they go with it or something?