I have a heap of coal coke mixed with slag, nails and rubble. I want to end up only with coke. I'd like to avoid the suicidal mundanity of picking every single individual piece of coal coke out of the heap. All soluble matter has been dissolved, all bouyant matter has been skimmed, all contaminants less than 1cm or greater than 5cm in diameter have been screened. What should my next step be?

I think that you have done about all you can do except use a magnet to extract any ferrous metal.  I once had a load of coke that had about 15% rock in it and I had to pick it out piece by piece from each shovel full I put into the forge.  The only way I could think of to separate it would be a heavy brine flotation process to get the lighter coke to float and the rock to sink but that seemed to be more hassle than hand sorting in each shovel full.

I thought about saving all the rock and taking it back to my supplier and demanding an equivalent weight of coke.

"By hammer and hand all arts do stand."

You’re basically down to density + magnetism + shape separation:

• Magnetic separation: run a strong magnet over the pile to pull out nails/steel bits.

• Air separation (winnowing): drop material in front of a fan—lighter coke travels farther, heavier slag falls sooner.

• Hand jigging/density table: shake on a sloped surface; denser slag migrates differently than porous coke.

After that, you’ll only need minimal hand picking instead of sorting everything.

Edited March 31Mar 31 by Mod34
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