I decided to check how much money you can make in 1 hour at Blast Furnace minigame during one of #TrueBF donation shifts making adamant bars.
1 hour of making mithril bars at Blast Furnace video here
#TrueBF is a clan which hosts both payed and donation Blast Furnace shifts. During these shifts you can take your bars pretty much instantly, because they have workers who takes care of machine and the only job you have to do is to bring your ores.
Their clan chat in-game is ‘TrueBF’.