pan out

verb

To separate and recover (valuable minerals) by swirling dirt or crushed rock in a pan of water, in the manner of a traditional prospector seeking gold.
“On the Saturday holidays in summer-time we used to borrow skiffs whose owners were not present and go down the river three miles to the cave hollow (Missourian for "valley"), and there we staked out claims and pretended to dig gold, panning out half a dollar a day at first.”
“His father came out in '49 with the gold rush crowd, panned out a good pile, and then, liking the life—San Francisco was a gay little burg those days—opened one of the crack gambling houses down on the Old Plaza.”
To proceed according to plan; to result or end up with an acceptable outcome or in an acceptable form.
“My hopes for a white Christmas didn't pan out this year.”
“We'll see what pans out from the arbitration process.”
To fall asleep.