Making my list and checking it twice

[viacin]

Ok. I've made a shopping list for my first step, the nitric acid bath. I'm trying to do this as economical as possible. I've read hoke's process, read the processes on the forum, and watched lazersteve's videos and this is what I've came up with:

35% nitric acid
glass stirring rod
electric single coil burner (or ceramic hot plate)
flat, 5qt corningware dish (or equivalent, to diffuse heat and catch spills)
1gal distilled water (tap water may be ok?)
spray bottle
large coffee filters
Pyrex beakers (1000ml, 2 req.)
Pyrex funnel (large enough to hold 4-5 coffee filters, but with a short enough stem to fit into your beakers)
chemical (acid) gloves, apron, respirator, and face shield. (if full face respirator, then face shield is not needed, but a good idea.)

3 Very Important Questions!

1. Can I buy nitric acid at a hardware store like you can hcl and sulfuric acid, or will I have to make my own, or buy the $40 bottles from chemical stores? Answer: NO. Not sold at hardware stores.

2. Hoke says to dilute the nitric before pouring into the coffee filters. Her formula recommends 70% nitirc, but if I use 35%, is it possible to pour the used nitric mix directly into the filters without diluting? Answer: YES. 35% will filter fine.

3. What precentage nitric acid should I buy/make? Hoke's process works out to 75%-80%, but also adds that some people use more water. I've been advised a 35% mix would be good. Any suggestions? Answer: 35% is best for this project.

edit note: I decided to update this for anyone new to the forum that is looking for a beginners shopping list. This is for a nitric acid soak, not aqua regina. Please read all of the reponse's for more information. Read the forum and Hoke's book before jumping in any furthur! The list has been updated to include recommended items and the questions have been updated to reflect current answers.

 

[Anonymous]

diluting with water = bigger beakers

or smaller batches, maybe.

I would also think that your nitric should be used up before filtering, so it should not be so reactive.

I use the acid I make until it will not work anymore then filter the left overs.

 

[Anonymous]

Ok. I've made a shopping list for my first step, the nitric acid bath. I've read hoke's process and watched lazersteve's videos and this is what I've came up with:

70% Nitric Acid
glass rod
hot plate
water
spray bottle
coffee filters
beakers (how many and what size??)
glass funnel
chemical gloves

I'm sure I'm forgetting something, so i wanted the ones more expierenced than me to check it over before I order. I'm going out of town tonight and won't be back till morning, at which time I hope to order everything.

MY OBSERVATIONS ON YOUR OMISSIONS

I know this is only a personal opinion but Eye protection, Respirator and protective clothing would be an area i would concentrate on rather than the size of beaker to buy, as has been mentioned many times on the forum, no amount of gold is worth risking your health and well being for.

Good luck with your processing, looking forward to seeing the results in the near future

 

[viacin]

"I would also think that your nitric should be used up before filtering, so it should not be so reactive."

This was my thought also, thats why I'm confused at hoke's step to water down the acid before filtering. Also, I havn't seen anyone else doing it either, but I figure she knows a whole lot more about it than I do. But if it's not necessary it could save me some time and money.


-----------------

"I know this is only a personal opinion but Eye protection, Respirator and protective clothing would be an area i would concentrate on "

well, full protection is on the big list, but not yet. I don't plan on doing this inside, or for that matter hanging my head over it to see how it smells. And I already have a pair of safty glasses (hope z87 rating includes a nitric test :? ) However spilling a drop or two on my hands is a high posibility, so I vote for the gloves.

 

[Noxx]

70% nitric acid is highly reactive. It will produce a lot of NO2 in a short amount of time if in contact with base metals. My recommendation would be not to use that, unless you dilute it to about 35%. Also, buying 70% Nitric acid is expensive and you won't find it in hardware stores.

Making your own (cold method) is not so hard and you can make ''cheap'' nitric acid to be used for base metals dissolution.

Personally, I use a full face shield, gloves and an apron when distilling nitric acid.

Beakers size depends on what you plan to do. I have 4 liters bakers and 100ml ones. They are both very useful

 

[viacin]

to be safe I decided to buy a apron and actual goggles too. Didn't think of the face shield though, would have been better.

How safe are pyrex measuring cups? You can get them much cheaper than beakers, and they can serve the same purpose. But are they chemical resistant?

 

[Noxx]

Yes they are. But they aren't pyrex anymore
They still carry the same name but the recipe have changed.
They are chemical resistant, unless your pour HF into them lol.

 

[Harold_V]

Be careful about choosing glassware if you intend to heat any of the processes.. Beakers are thin for a reason. They are not only borosilicate glass, but are thin to minimize thermal shock. Thick glass often will not resist heating due to the uneven expansion. Glass is not a good conductor of heat.

Harold

 

[viacin]

noxx.

HF = hydrogen fluoride? The glass etcher? LOL
What precentage Nitirc acid should I use, 35%? I was basing my figure off of Hoke, her formula works out to 75% - 80%. However she does add, "Some people use much more water."

Harold.

Good point. I will have to heat the glass. I'm following Hoke's gold refining process on page 50 of the e-book "(3) Treatment with nitric acid". I'll be boiling the nitric in the beakers or measuring cups. But are not these cups mean't to boil liquid in, albeit something less corrosive? I've found a "vintage" one, I wonder if it's still borosilicate glass.

http://cgi.ebay.com/VINTAGE-PYREX-4-CUP-MEASURING-CUP_W0QQitemZ320306770831QQihZ011QQcategoryZ4765QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

This is the last thing I have to buy, and then I'm at the mercy of the U.S. Post Office. 8)

 

[viacin]

btw, respirator. Necessary, or just a good idea? I'll be doing all my work outdoors, and probably still set up a fan for draft.

 

[viacin]

"What mask cartridges are made to block NO2? I haven't been able to find any that will" rag and bone, and noxx answered my respirator question in the safty section, didn't see it

 

[Harold_V]

I will have to heat the glass. I'm following Hoke's gold refining process on page 50 of the e-book "(3) Treatment with nitric acid". I'll be boiling the nitric in the beakers or measuring cups. But are not these cups mean't to boil liquid in, albeit something less corrosive? I've found a "vintage" one, I wonder if it's still borosilicate glass.

As far as I know, measuring cups are not intended to be heated. They are also not likely to be borosilicate glass, although I don't know that they aren't. There's really no need, and it is more expensive and melts at a much higher temperature than common glass.

Considering you intend to heat (I commend you for your good reasoning), and want to purchase common items instead of lab ware, make sure your purchases are intended to be heated. There's a good selection available, although you may not find deep cylinders (beaker type) containers. I can't think of anything that was more disconcerting than to have a container of values break when everything was in solution.

Harold

 

[Oz]

Old Pyrex coffee pots are the closest you will get to a lab grade beaker. Pyrex kitchen ware is not what it used to be. I swore off using Pyrex measuring containers for anything heated even mildly after I had a 4 cup Pyrex measure shatter explosively when ½ full of auric chloride under very mild heat. I was lucky to have it in a basin that caught most all of it, not to mention the hazard of flying shards of glass and acid. This is even a good procedure to follow with professional lab glass.

 

[viacin]

You're right, the last thing I want is the glass to break, or even worse explode. I think the smart thing may be to bite the bullet and buy some beakers for safty.

I did find this though, although no telling how reliable it is. It's from http://www.shopwiki.com

Pyrex® -- the best-known brand name for borosilicate glass -- is a reliable kitchen standard.
Glass cups have the advantage of being microwave safe, so you can melt chocolate chips or butter in under a minute.
Pyrex® is heat resistant, so if you pour hot broth into the cup it won't distort or shatter it.
Any other kind of glass is not recommended for measuring. Look for either Pyrex® or another borosilicate glass.

Notice how it says it's meant for hot liquids to be poured into it...does not say able to apply heat to, or boil liquids in. So I think beakers will be a better choice.

I still feel like I'm guessing on the ml I need though, because I've never actually seen any beakers in person. but if 236 ml = a cup, then 500 and 1000 ml beakers seem like a good start to me? But if I have to water down the nitric before pouring it into another beaker, then my sizes need to be larger...gah... I can answer this question, and order my final items, if I knew if I could pour directly into the coffee filters after the nitric has disolved all the impurities, and at what percentage the nitric should be to begin with. :?

 

[Harold_V]

Get a few 1,000 ml beakers to get started. In the end, you may find you like larger or smaller ones. I kept all sizes from 400 ml up to 4,000 ml on hand, and used them all. All depended on the nature of the material I was processing at any given time. The most used were the large sizes (3,000 & 4,000 ml), however.

I wouldn't hurt you to keep watch for old coffee containers, if you're so inclined. I'd suggest you avoid any with metal bands, or remove the bands. It's not a good idea to have metal objects included with your refining.

Harold

 

[viacin]

TY Harold. TY Noxx. TY Oz. and TY james122964. My order is in I updated my original post to reflect the new list, and to hopefully get some help clarifying a couple of questions (#'s 2 and 3).

 

[Noxx]

2. (STILL CONFUSED) Hoke says to dilute the nitric before pouring into the coffee filters. Her formula recommends 70% nitirc, but if I use 35%, is it possible to pour the used nitric mix directly into the filters without diluting, or will it disolve them? If I must dilute/neutralize, is there a better way than adding water?

3. (UPDATED) What precentage nitric acid should I buy/make? Hoke's process works out to 75%-80%, but also adds that some people use more water. I've been advised a 35% mix would be good. Any suggestions?
[/i]

2. If you use 35%, you will have no problem at all filtering. My suggestion would be to neutralize before if you can. This way, filtration is the last step before neutralization and removes all the insoluble matter.

3. 30%-35% works very well. Stick to this for the moment. When you'll get more experience, you could try with higher concentration. Do not forget that heating your solution a bit increases the dissolution rate a lot !

 

[viacin]

TY! I feel confident to take the next step now. Something I would have never dreamed of just two weeks ago. You guys have taught me so much in very little time. i feel like passing out the brewskies now. You guys are awsome! Vive La Forum!

 

[P_CARROLL]

Get rid of the hot plate and use a crockpot pot. Hotplates throw out alot of radiant heat and constantly need to be watched. A crockpot on the other hand willhold a 2 liter erlenmeyr flask inside of it and will maintain a more constant temprature. See this thread http://goldrefiningforum.com/phpBB3/viewtopic.php?t=645&highlight=

good picture a lil ways down and you will see what im talking about.

 

[viacin]

uum, I don't cook (at all) but don't crock pots heat up very slowly and take a while to reach decent temps (like a hour or more)? Also, the one at my house has very little adjustment to the temp at all. The heat wasted by a hotplate isn't too much of a concern, no more that that wasted by a stove top while cooking. The ideal situation would be a ceramic hot plate with stirring features like the one shown below. However, not everyone has the pocket book for one of these.

http://cgi.ebay.com/VWR-720-Advanced-Hot-Plate-Stirrer-to-500-C-60-1600rpm_W0QQitemZ230285376152QQcmdZViewItem?_trksid=p3286.m20.l1116