# Hydrofloric acid



## Circle 65 (Jan 22, 2013)

What type of vessel or beaker can I use to digest cat pellets. Have about
three pounds of material that I have roasted all the carbon off. They are
now clean and white...Have a bottle of hydrofloric. I just wonder about
types of plastic or teflon being a problem. I have a fully supplied lab
with fume hood, furnace, etc. Have been working with Au, Ag, dental
and medical pt but wanted to experiment with cat converters. Have about
10 units on hand. Will I get a workable residue after digestion to go with
a lead collector?


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## NobleMetalWorks (Jan 22, 2013)

Why in the world would you play around with hydrofluoric acid? Of all the ways you could process cats, why would you mess with an acid that incredibly dangerous?

There is really no reason to risk your life by using hydrofluoric acid. The only reason you would use it is if you had PGMs locked up in alumina silicates (Zeolites) and even at that all it takes is about 10% in AR to do the trick.

There is a wealth of good solid information on how to safely process cats. Seriously, if you believe Hydrofluoric is the best way, you have not done enough reading to even begin to mess around processing cats. There are no PGMs locked up. The PGMs are deposited on the outside of the alumina silicate material, not the inside. Please, before you start playing around with Hydrofluoric acid, read this:

http://web.utk.edu/~ehss/training/has.pdf

And if you still insist on attempting to use hydrofluoric acid to process your material, I hope to God nobody here gives you any pointers that could potentially lead to you using the acid, and killing yourself. If you just spilled enough on your body to cover just 2%, you have most likely just killed yourself.

Scott


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## Circle 65 (Jan 22, 2013)

OK thanks Scott. Will scrape that idea. I will do some more research.
Actually that is where I got the idea of using HF in the first place. Perhaps
I'll just sell the material...
After alll the reading I have done grinding and using AR sounds a little too 
simple....Did I miss something? James.


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## nickvc (Jan 23, 2013)

James I'm glad you took Scott's advice, hydrofluoric is one acid to be very afraid of, hot concentrated sulphuric comes a poor second.
With cats you can home refine them but in my opinion its only worth it if you can get them free or cheaply but whenever you use acids to refine them some of the values will end up trapped in the substrate similar to jewellers sweeps. If you have volumes or can get volumes the big commercial refiners will beat your recovery rates by outright purchase price but they use giant arc furnaces not acids to recover the values. Selling to a large collector may get you nearly as much as the refining return without the work and costs.


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## NobleMetalWorks (Jan 23, 2013)

I am so glad you decided not to use hydrofluoric to process cats. 

I'm sorry if I came off really stern, or worse a jerk, but when I saw this post it concerned me so much that I felt it necessary to post the safety concerns, so at the very least anyone who comes after, and reads, will understand how incredibly dangerous it is.

I apologize if I offended you, but it does do my heart well to know you are taking this serious, and have decided not to process your cats in this way.

Scott


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## Woodworker1997 (Jan 23, 2013)

Scott,

Very, very good advice. HF is seriously scary stuff. Just a small amount of the vapor will make you dead quickly.

Derek


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## Circle 65 (Jan 23, 2013)

Wow I am impressed with the response and safety concerns and thank all
of you for the warnings. 
I did get the cats free they were given to me from various people over the 
years. I am cleaning up old inventory. 
I am still going to experiment with the pellets that I burned the carbon off
from. I love to work with platinum it is a fascinating metal...
This forum is great wish it had been available some years back....James


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## butcher (Jan 23, 2013)

Trying to dissolve the ceramic to get the pgm from catalyst, is kind of similar to dissolving the quartz rock to get the gold, where it may be easier and safer to process the ore and leach the gold from the ore.


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## Aristo (Jan 23, 2013)

The OP is very well advised to avoid the very dangerous Hydrofluoric acid. Even though you will not be using it, the fact that you have it on your premises dictates that you must have calgonate ( Calcium Gluconate) or similar on hand as well.


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## Circle 65 (Jan 24, 2013)

Went to the coast yesteday and returned the acid, msds, and kit that came
with it. They credited my account as It was never unpacked. Transportation
require placards. I was going to Sea anyway in POV. End of Story.


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## mjgraham (Jan 24, 2013)

I have to say, that is pretty good, I have never used it or wanted/needed to, but the fact you took it back after hearing the bad side of it means you are serious about being safe. Most new people on here just start spamming at this point or raise some other kind of stink or just get hurt.
Cool.


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## NobleMetalWorks (Jan 25, 2013)

It does my heart well to know you took what was posted seriously.

I worry about a lot of the things we post on this forum. I worry that others will come behind, believing they know better, or ignoring the safety issues and do some real harm to themselves or others. This is one of the only examples of someone truly taking heed, then taking action, and not being offended by what was said in open forum. I bow my head to you Sir, well done! It not only puts you in a totally different class of forum members, but it also promotes you, in my humble opinion, for whatever little it might be worth, as a person of responsibility.

Scott


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## Circle 65 (Jan 25, 2013)

Again thanks to all who responded to the safety issues...The responsable
part of the equation can also be costly to attain. In the 60's I had a tech
job with a company that produced weapons grade plutonium. Then the 
70-90 period I worked for the Navy weapons dept and undersea warfare.
Both paid well, however I have had two major medical problems because
of the hazzards of the job..I am a Viet Nam vet as well. 
Needless to say I don't need any second warnings of hazzard in the path
ahead. I have been fortunate on every roll of the dice so far. I am not
going to gamble again at this point. 
So with that said I will confess I knew little of the problems with hydrofloric
acid when I submitted that post. And that is why I returned it to the Chem
company. This forum rocks. James


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## FrugalRefiner (Jan 25, 2013)

James,

Welcome to the forum. We're all glad to see you're here to learn and that you're willing to follow good advice.

The amount of information on this forum is immense. It will take a while to get used to how things work here, let alone understanding the processes we discuss for reclaiming and refining precious metals. Here are some links to get you started.

The first rule is to be safe in everything you do. You've already learned that one! Before you jump into any of the processes you see discussed here, be sure you understand the potential hazards and do everything you can to minimize the risks. Read EVERYTHING in the Safety section of the forum, especially the Dealing with Waste topic.

Follow the Guided Tour created by LazerSteve. It will provide an introduction to the forum and numerous valuable links including the General Reactions List. Be sure to follow the link to his web site as he has many outstanding videos, a collection of great reference documents, and he sells a lot of the supplies needed to get started including detailed instructional DVDs. Samuel-a also has a lot of videos, guides and tutorials at his web site Gold-N-Scrap.

Download C.M. Hoke's book Refining Precious Metal Wastes. You'll see her book mentioned repeatedly here on the forum for good reason. It is probably the best book ever written for the beginner who wants to learn refining. It is written in layman's terms and will provide a solid foundation that will help you understand everything you read here on the forum.

Once you understand the basics you can start to try some small scale experiments. If there's something you don't understand or you get stuck, there will be someone here to help you.

Best of luck,
Dave


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## goldmike (Mar 7, 2013)

Circle 65 trust and believe these guys they know what they are talking about. I have recovered a few grams of gold and know very little ,but i'm reading and learning . great bunch of people here and as soon as I get some $$ rolling in ( just paid taxes  you know ) I'm going to kick in a few bucks to help support this wonderful forum !! I have been treated very well here and when they could have kicked me out for using words like a sailor fresh off the boat ( I drank little too much wine  ) The admin just asked me nicely to be a good boy  and all was good. I love reading everything here and can't believe they don't charge $$ for this info !! Mike


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## Beetle Juice (Jul 9, 2013)

I once worked with the HF, do anything you can to avoid it. These poor chaps in south korea

http://www.cbc.ca/news/world/story/2012/10/08/south-korea-acid-spill-disaster-zone.html


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