[toanandmishra]

I am trying to extract gold from old electronic parts , extracted gold foil using hcl and hydrogen peroxide. Now how to purify the gold foil upto a scalable value.

[ATMyller]

Industry uses electrolytic refinement when the gold is in dissolved state. If it is in solid form then electroparting, sluice box or rocker box.
Very small amounts can be isolated by filtering, panning or smelting.

[Enthalpy]

While it's an excellent idea to recycle scrap, I hope you've evaluated the value of the gold and the amount of scrap. It is done presently in poor countries like Bengladesh where wages are low and health and environment protection law not too costly. The chemical used for gold up to now are yuk.

Maybe it's not the same job to extract a decent gold concentration from scrap and to purify that gold? Many people do already the second step, so you could stop your part before.

Gold purification often uses cyanides and mercury in big amouts. Personnally, I'd avoid both.

[aga]

There are many many references to Gold recycling.

Look on utoob for sreetips.

He has very clear videos of the standard nitric acid/sodium metabisulphite route and also a safer salt, bleach, vinegar and vitamin C route.

With the second route i was lucky enough to take part in the preliminary experiments to prove it's viability.

[toanandmishra]

If i convert the solid scrap to aucl3 i.e. gold chloride then how can we get the  using electrolysis.  As electrolysis process is nearly unknown to me as never been tried before

[Enthalpy]

AuCl₃ isn't soluble in water. Do you plan an other solvent? Wiki cites ether and liquid ammonia, both dangerous and difficult...
https://en.wikipedia.org/wiki/Gold%28III%29_chloride
Solubility in water is why people use the very toxic cyanides, which I suppose is too dangerous for you if you have little experience. You would kill yourself at the first intent.