nitric vs hydrochcloric as leech

[martymcfly]

Hi everyone,

Appologies if this is a stupid question, Ive tried searching for my answer but not found anything conclusive.

When leeching pm from escrap like fibre processors etc is there any reason why you would use nitric acid over hydrochloric since nitric seems to have a few more health risks. From the posts ive found and videos ive watched hcl seems to work pretty well at removing base metals in itself.

I think ive stumbled upon the answer, Hydrochloric struggles with copper removel without an oxidizer where nitric just gets to work. So all in all nitric is the stronger acid but comes with the added risks.


thanks in advance

 

[rickbb]

Search for the AP process. It uses Hcl and household peroxide as the starter oxidizer to dissolve the base metals and not gold. Allows you so separate the gold to dissolve alone. Yields cleaner product, slower than AR, but less costly.

Hcl is cheap and available at most big box home stores that carry masonry supplies. Nitric is expensive and hard to get for most home users.

 

[martymcfly]

Thanks rick,

Ive read the AP process but had found this post by sam http://goldrefiningforum.com/phpBB3/viewtopic.php?f=39&t=9693 where he uses only heat and it seems to work well for him but have come across a few posts by other people where there have been some problems.

Luckily i live in the uk so Nitric doesnt seem to be an issue to get though it is quite pricey at £20 a litre.

 

[Harold_V]

Luckily i live in the uk so Nitric doesnt seem to be an issue to get though it is quite pricey at £20 a litre.

Heh! We can buy pretty much all we want here in the States for that price, too.

Nitric, when purchased in bulk, can be had for around $4/gallon in tech grade. Regulations make it difficult, however.

One of the major problems with using HCl is that it does not deal with silver. While I concentrated my efforts on karat gold and inquartation, many, here, are served perfectly well by using HCl. What you refine will most likely dictate if it works for you, or not.

Harold