'Furnace' in the Bible

When I turn my attention to you, I'll refine your dross as in a furnace. I'll remove all your alloy.

And he shall pass over to his strong hold for fear, and his princes shall be afraid of the ensign, saith the LORD, whose fire is in Zion, and his furnace in Jerusalem.

Behold, I have refined thee, but not with silver; I have chosen thee in the furnace of affliction.