[RedSandBlueSky]

ok here's the g.o.

iv'e recently been given a 15kg block of slag which was the left over from a pretty sloppy mining operation in central australia. the block of slag on appearances is just a bubbly, messy lump of copper which is also shot through with gold.
just on outside apperances it seems to be about one third gold and seems like it would be worth the effort to try and recover the gold in some way. a scrap dealer will definalty under estimate the scrap value of both metals and if there is a methord of separting them id like to give it a go with at least a small part of the block, partly for the fun of learning something new aswell.
ive come across many diffrent methods described on net but none seem to be a good fit for the application.
i have easy access to chemicals and other equipment that ive seen used in most methods.
what im after is a helpful and informative person who can give me a step by step method that uses commerically avalible products.
 any advise would be helpful. thanks
P.S. is ferric chlorid helpful at all?

[Doctor science]

A method for separating gold containing elemental gold and elemental copper is treated with an aqueous cyanide solution to produce a liquid product containing a gold-cyanide complex and a copper-cyanide complex. The liquid product is then delivered to a nanofiltration membrane which prevents the copper-cyanide complex from passing therethrough while allowing passage of the gold-cyanide complex. Nanofiltration of the liquid product specifically produces (1) a retentate which contains the copper-cyanide complex; and (2) a permeate which contains the gold-cyanide complex. In this manner, the gold-cyanide complex is effectively separated from the copper-cyanide complex. The permeate is then treated (e.g. with activated carbon or elemental zinc) to ultimately obtain elemental gold therefrom. The copper-cyanide complex may either be discarded or treated to recover elemental copper from the complex.