Dubai would be convenient place to transact
How is the gold going to end up in Dubai if the owners of the gold are blacklisted? You think it's a matter of moving it through a thin air without any form of proper documentation? 
If someone is on the UN blacklist, then there must be some reason for it, maybe the problem is in the exploitation of labor, the abuse of children in mining? I have done little research on gold mining in the DRC, and thousands of people seem to be doing it privately, and their health is being damaged, as well as causing considerable damage to the environment.
https://globalpressjournal.com/africa/democratic-republic-of-congo/hard-breathe-gold-mining-drc-damages-miners-forests/
https://observers.france24.com/en/tv-shows/the-observers/20210407-videos-show-children-as-young-as-10-working-in-gold-mines-in-dr-congo
Very likely. Been watching short clips about this about Child laborers on CNN.https://globalpressjournal.com/africa/democratic-republic-of-congo/hard-breathe-gold-mining-drc-damages-miners-forests/
https://observers.france24.com/en/tv-shows/the-observers/20210407-videos-show-children-as-young-as-10-working-in-gold-mines-in-dr-congo