NewB Question Don't Shoot me.

[Lost boy]

Hello
I hope this request in in the proper area and in line with the fourm rules. I am new and emphasis is on new too this forum and to the refining and processing of PM’s. I have downloaded Hoke and have started to learn how to produce some of the acids that will be used in the refining process. Today for the first time in the learning process I tried to produce a small amount of nitric acid. During the process I developed a question and searched the forum for answers about evaporation and fluid loss, probably inaccurate terms as nothing I found really applied to my situation. I devloped a process question while I was working outside and the weather was around 38 degrees. I used a filtering flask, PVC tube and glass pipette inserted into a graduated cylinder filled with fluid placed in an ice bath. After adding the materials called for in the recipe and sealing the flask the reaction appeared not to start due to what I thought was the outside temperature. I applied indirect heat to the outside of the flask by heating a sock filled with rice in the microwave and wrapped it around the flask which started the reaction. I expected to see a return of nitric acid equal to the starting fluid in the graduated cylinder, to my surprise the fluid in the cylinder had reduced to about half in volume. My question: Is this normal to lose so much volume in the process, was possibly too much heat applied in the process. It could also have been due to the cold, I may also have not been as watchful as necessary and when the reaction slowed due to lack of heat possibly the nitric was vacuumed back into the reaction mixture.
Thank you for reading and for any guidance you can provide.

Paul

 

[butcher]

I have no idea where you got that idea to make nitric acid, the whole thing sounds like a bad idea to me, you really didn't give much information of the chemicals and how much you used, and other details, but there is no way I would vapor off nitric acid in a microwave, especially with a carbon source, this is a disaster fixing to happen, I would stop playing around before you kill yourself or hurt someone.

(you could have nitrated the cotton, making it very dangerous of combustion)
(heating the sealed container is just asking for trouble, especially with a dangerous acid)

 

[Geo]

pretty simple really and a good chance to pass along some needed information to new people. most liquids expand when heated (much like everything else) and contract when cool. when you sealed the container and warmed the liquid, it expanded. while the reaction was happening, it warmed the solution further causing more expansion. after the reaction subsided, the solution cooled and contracted creating a vacuum inside the sealed flask.

and what butcher said.

 

[sharkhook]

Lost boy,

If you got that idea from where I think you did, (youtube), there is quite a bit missing in your process. It is also missing from most how to video's on youtube as that leaves the video un-cool for the viewers. Of course it is right in the opening to start with in most of the video's. Watch those video's and if they allow it, watch the rubber stopper in the flask. You will clearly see it melting, that is ACID, not heat. (Remember,heat was not used) The method you are talking about does NOT use heat. (And Thanks to GEO, I am way more careful where heat is concerned now than ever.)



By the way, what is missing in the video's, real SAFETY.

 

[Lost boy]

pretty simple really and a good chance to pass along some needed information to new people. most liquids expand when heated (much like everything else) and contract when cool. when you sealed the container and warmed the liquid, it expanded. while the reaction was happening, it warmed the solution further causing more expansion. after the reaction subsided, the solution cooled and contracted creating a vacuum inside the sealed flask.

and what butcher said.

Thank both of you for your input.I agree placing a sealed container in a microwave and turning it on IS JUST PLAIN STUPID! As this was my first attempt I will try to be clearer in the questions I bring to the forum in the future. My question revolved around process not formula. I thought that I had most likely vacuumed the nitric back into the solution through contraction although the possibility of evaporation was there hince the question. Just to be clear the flask was not put in the Microwave, Just the sock with the rice was placed the microwave and heated to around 70 degrees and then placed outdoors,( This sock process also works realy nicely when your toes are cold place two cups of long grain rice in a tube sock tie the end place in microwave on high two - three minutes place on where you hurt ) the water in the rice adsorbed heat and when wrapped around the flask like an hot water bottle provided gentle flame free heat to adjust to a more normal temperature in the flask as the OAT was @36 Degrees. The flask was not tightly sealed as the vapor was transported to an open to atmosphere at the top cylinder filled with fluid through a PVC hose and pipette, placed in an ice water bath.

My Hope is to Live so I can learn

Paul

 

[butcher]

I guess I misunderstood I thought you sealed the vessel of nitric and heated it in the microwave.
I still would keep the cotton, paper, or organics away from nitric, you can make nitrocellulose by mistake (especially if the nitric is concentrated). I also would not seal a vessel with active nitric acid, where nitrate salts and acids are reacting forming gases in solution, and as stated above nitric decomposes rubber so rubber stoppers should not be used around nitric acid.
The reaction of heat forms NOx gases as the reaction occurs these are most like what raised the level of the liquids and when they escaped were left on top of the solution as the level of solution settles back down, these gases can pressurize a vessel with a sealed lid, if the pressure raises more that the lid or the vessel can contain they could pop a lid or worse.

Sorry, I apologize, I misunderstood your post, I miss read it, and thought you were doing something worse than you did...

please be careful just like I misunderstood what you wrote, it is easy also to misunderstand instructions, this stuff is just too dangerous to get things wrong.

 

[sharkhook]

Acids scare me, at least enough to be extra careful around them. Do a forum search for Cold Nitric. (No heat involved.) Read through those posts good. Then look for Poor Mans Nitric. Should be safer than what your attempting. I am new at this as well, so I may be wrong, but the super concentrated nitric isn't (always) required. There are many good post here that will lead you to what your looking for, and do so in a safer manner. butcher and Geo both have many great post, and easily understood. ( with a bit of care)

Good Luck!

edit: There are many great post's by other members as well.

 

[Lost boy]

Butcher / Sharkhook

No offence taken! I respect your knowledge and agree I have a lot to learn before I attempt to actually be productive and refine any material. The information this forum offers is a value beyond compare and I hope in time to actually be a contributing member, I just ask be patient while I cut my teeth.
Sharkhook you are correct in your assumption on reference material. I was injured last year and need something to consume my time hopefully this fills the bill. When observing the YouTube videos I had noticed there appeared to be a lack of safety precautions. I am in the process of building a fume hood and a small collection of lab ware it will take a little time to figure out what is really needed.

Thanks again
Paul

 

[butcher]

I tried again to understand what you are trying to do, I am still having trouble understanding, it kind of sounds like you are trying to distill off the nitric acid.

nitric acid when made, with a sodium or potassium nitrate salt and sulfuric acid forms nitric acid (NOx gases), and a salt of sodium or potassium sulfate or bisulfate (depending on concentration) depending on which salt you form and the temperature will determine How much of the salts are soluble in the acid.

Potassium is less soluble but can also trap more nitric in the salt crystals when they form especially when cooled too fast.

Before distilling the acid it can be helpful to make up the nitric first, a 50 to 70 % HNO3 solution, Using water in solution to help dissolve the nitrates either water added first, or as part of the dilute H2SO4, using heat to dissolve the mix, and then chilling to remove as much of the sulfate salts,this helps to convert the nitrate salts to sulfates, and get the acid into solution, by chilling out the sulfate salts, and removing them from the nitric acid, this way you do not have as much of these salts in the nitric or in the distilling rig.

To distill nitric we basically vapor off gases and condense them (or bubble the gases into water) to convert them back to nitric acid, the hot reaction flask must be heated with a controllable heat source to get a constant distilling temperature of the liquid being distilled.

If a hose from this hot reaction vessel is used to bubble gases into a receiving container of cold water, care must be taken not to lower heat on the heated flask, while heated the boiling flask pressurizes as gases form pushing these gases of decomposed nitric acid through the hose , bubbling them through the cold water, But if we lowered heat on the boiling distillation flask this flask would go into a vacuum, and suck that cold water back into the boiling hot flask bursting the distilling flask of hot acids, hot acid and broken glass flying all over is not something you will want to be around, as the glass is thermally shocked by the instant change in temperature, the hose would need to be removed before lowering the heat on the boiling flask to break the vacuum before lowering heat, so that the vacuum would suck back air and not the cold water.

The nitric acid will have a boiling point (we can evaporate below this boiling point), to distill we will need to heat the liquid close to this boiling point, the boiling point is different depending on the concentration of the acid, the acid concentration can change during the distilling process (unless it was made 70% to begin with), if the acid is dilute water vapors off before the nitric distills over, (there will be some acid in the water vapors but they will be mostly water), the acid in the boiling flask will concentrate, until it gets to 70% HNO3. then the fumes and vapors would contain the acid at this concentration, the acid would vapor off until all liquid has vaporized off, or you are left with just the sulfate salts.

 

[sharkhook]

Butcher,

What I think he is attempting is to add nitrate to a flask, then water to dissolve it. Then add a calculated amount of copper, and complete the rest of his set up. The tube and pipette are arranged. The catch flask uses generally Hydrogen Peroxide, water will work, lower strength. Once set up add Hydrochloric Acid to the distillation flask and stopper it with with the tube and pipette in the stopper. (Maybe the flask with the vent on the side.) The reaction it's self is supposed to generate enough pressure to bubble the gas through the receiving flask, which is normally a tall narrow container. (Test Tube, but larger, can not think of the word for it.) And each ingredient is a calculated amount. You have to stay close, or you get the vacuum back very easy.

I saw it on youtube as well. I know, but it is how I got here, too.

Sorry for the lack of technical terms, I am learning as well. And my hands hurt, I did pull 95 grams of pins today.

 

[butcher]

http://goldrefiningforum.com/phpBB3/search.php?keywords=kill+two+birds+one+rock&terms=all&author=&sv=0&sc=1&sf=all&sk=t&sd=d&sr=posts&st=0&ch=300&t=0&submit=Search

 

[sharkhook]

I have several questions and would like to go with a few at a time, with the new people in mind, for simplicity and safety.

I have read and re-read butcher's how to kill two birds with one stone and like the idea of making something useful from another process. I just don't have the equipment for it right now. Plus I am not geared up for working with multiple types of material at the same time. (I will be coming back to his post, it is just to good to not to) And I hope to get some grasp of one material before before attempting another.

So by starting small, and keeping the newer people in mind. And this is not for those with no clue. This stuff is dangerous in every way!

What would be considered the safest method of making nitric in smaller quantities?
I need a small amount for testing materials, I see no sense in processing something of questionable or no value. The "Types of PM Scrap" section is a great area to learn much of this. I have some gold recovered from finger foils and some recovered from pins, with more to come. I know this will be cluttered with tin and lead. I am preparing for this buy studying Hoke's section "PROCEDURE WHEN TIN AND LEAD ARE PRESENT ACID METHOD". (Page 80 by the PDF page number,Page 71 by the book page number) Anyway, I will be needing to make my first attempt at refining this material fairly soon, I hope, so will need a bit there as well. I also won't likely be using a lot anytime soon, so I hate to buy a large amount to just have sitting on the shelf getting old.

 

[sharkhook]

Some help understanding evaporation and boiling. Please read, carefully to the end, so the difference is understood.


http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=37&t=13098

 

[butcher]

Making nitric acid using the cold method is fairly easy, it will make the nitric at a usable concentration for base metals, using Laser Steve"s formula and instructions, (which should be easy to find on the forum, I believe it also may be in the general reaction list or the guide to the forum , or the forums book made by Palladium).

I do not have that recipe with me now, but will give you a recipe that is similar:

In a Mr.Coffee Pyrex glass coffee pot, on a solid burner electric hot plate.
Add 600 ml water (about 21/2 cups H2O), heat it up to a boil.
Add 1020 grams of NaNO3 (sodium nitrate) which can be bought as garden fertilizer,
Or
Add 1212 grams of KNO3 (potassium nitrate) which can be bought as stump remover.
(about 2 one pound bottles)
Stir to dissolve the nitrate salts into the boiling hot water.

Lower heat (I lower it to warm), but cooling it to room temperature is better or safer, as the next part of adding the acid tends to generate a lot of heat and must be done slowly and carefully.
Add very slowly and just a little at a time, letting solution cool some between additions.
Add slowly 336 ml of 98% H2SO4 concentrated sulfuric acid, which can be bought as drain cleaner.
let cool between additions, at first additions the reaction will be strong and try to foam over as you add the acid, after the solution gets acidic this reaction is not as violent.

(battery acid could be concentrated and used if needed, but if you are using battery sulfuric acid I would go with a different formula and concentrate the nitric later, I can discuss that another time).

After the acid is in solution I normally add enough heat an stirring to get all of the salts into solution, once dissolved, I will lower the heat and cool it very slowly (with potassium salts the slower you cool it the better.
I like sodium salts for making nitric better, but potassium salts are better for waste treatment, potassium salts tend to form crystals that can lock up some of the nitric acid if cooled too quickly.

Let solution cool to room temperature, some sodium or potassium sulfate salts will form, decant the liquid from these salts, (save the salts, you can make copperas with them, or use them where you need sulfates), I put the solution in canning jars (do not fill plumb full leave a little room for expansion, a plastic lid from peanut butter works for a lid for the jars, you can now freeze the nitric acid in a freezer, to crystallize out most of the sulfate salts, (sitting in the snow overnight in winter, or an brine Ice bath will also chill the solution).
decant the liquid nitric acid while still cold to your nitric acid bottles, (clean blue or amber wine bottles with plastic lids will work, if you do not have nitric acid bottles (save the sulfate salts with your other batch above).

This will make a fairly strong nitric, which I normally dilute for base metals.

If you plan to use this for silver or to make aqua regia, I suggest distilling it, for Aqua regia you can concentrate it to 70%. Distilling will remove the sulfate salts that can affect your silver or aqua regia process.

Dilute acids can also be used with heat, they will concentrate as you work, and fume less wasting less of your acids, many time I start with my acids more dilute, as I like to use heat to process metals with.

A lab distilling rig can be bought for around 60 to 80 dollars or more, you will probably want to get one.
But you can distill without one if needed, you can use a Pyrex coffee pot (see picture below), a pickle jar and sand bath as described in the thread killing two birds with one stone) or lab glass that can handle the heat like an Erlenmeyer Flask...
Use Teflon for corks, you can make your own with a hole saw and drill or in a lath, you can get thick sheets of Teflon materials.
PEX tubing (cross linked polyethylene) used for plumbing will work, it can also be coiled in a bucket of cool water for a condenser, the gases can be bubbled into a receiver bottle or jar ( starting with just enough water and 30% H2O2 for the gas to bubble into, I tie the receiver bottle down in a bucket of cold water, so it does not float before it is filled.

In the thread link in the post above I give pretty good safety tips on distilling, if you have never distilled I you should read that or some other safety on distilling, HOT ACID in a closed container under pressure, is nothing to take lightly, suck back from vacuum and a bursting container of hot acid is not something you will want to have happen or be standing around.

When I distill I get me a chair and watch the process, with a good book like Hoke's, I never leave it unattended.

 

[sharkhook]

Thanks Butcher, if we can't understand that we need a new hobby.

Anything that will dissolve metal can not be good for any part of the human body!
Proper disposal is just as important as creating the needed acids, don't just dump chemical wastes without knowing who/what could be harmed, and how to prevent that harm.

As for the selection of the nitrate and the use for copperas, would potassium or sodium make the better salts for making copperas, or do they work the same? I like that the "waste" can be made into something useful. But, if it is not needed, what would be a good way to dispose of the sulfate salts. Just so no one gets in trouble with their waste.

 

[sharkhook]

A bit of reading for those who haven't learned some about copperas.

Reference page 64 of Hoke's book..Paper edition
Screen readable version Page 73..PDF page

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=48&t=14026

edit:spelling correction and more spelling

 

[butcher]

From the recipe I gave above you would have Na2SO4 or K2SO4, these are not acidic enough to dissolve iron easily (like bisulfate salts NaHSO4 or KHSO4 will, these can be a substitute sulfuric acid in many reactions), but with a little H2SO4, and heat added they will easily make copperas or iron sulfate, also called ferrous sulfate (used to precipitate or test for gold), You could also use them make other metal sulfate salts if you wished.

Basically you would treat these salts for waste just as you do your other waste, they could be added to your other waste solution, or treated separately, dissolve them in water, add a little H2SO4, add Iron, (to make up some ferrous sulfate) then bring to pH 9, let iron sludge(iron hydroxides) settle, decant, adjust to pH 7, again let any sludge settle, decant salt water, dry the sludge...

Or the dried sulfate salt in the proper container (labeled as to what it contains) can be taken to your local waste disposal facility, these sodium or potassium metals as sulfates are not safe, (but safer than if they contained metals more less reactive than the sodium or potassium metal, like copper which can be more poisonous).
http://www.chem.tamu.edu/class/majors/msdsfiles/msdssodiumsulfate.htm

 

[sharkhook]

By now making basic, usable Nitric should be fairly clear, as well as cleaning up and proper disposal of the waste's. (If it isn't read it again. That is basic as it can get.)

(battery acid could be concentrated and used if needed, but if you are using battery sulfuric acid I would go with a different formula and concentrate the nitric later, I can discuss that another time).

When you can, please explain this for those who cannot get the stronger Sulfuric Acid. I had a problem when first looking for it, but finally found a decent source locally, and at the same price as battery acid per quart.

 

[butcher]

I will spend more time discussing this later.

Basically, with the more dilute acid we have more water involved, and will make more dilute acid.

If you look at what we did above we added water to dissolve the nitrate salts, then added concentrated sulfuric acid (so basically we diluted the concentrated acid in the reaction).

With battery acid we have 29% to 32% H2SO4, and 68% to 71% water involved, we can adjust the amount of nitrate salts and make a weak acid of somewhere between 20% to 30% HNO3. and concentrate it to 68% by evaporation, or we can concentrate the battery acid to A higher percent H2SO4 and use that to make stronger nitric acid.

Without spending time on the math right now, I say you could evaporate the battery acid down to about half of its volume, getting it closer to 60% acid, and use that in the formula above for the acid, (without adding water as stated above), but I would look a little more at the math if I didn't want one of the reagent to be the limiting reactant, in the reaction.

You can concentrate nitric acid up to 68% by evaporation, so if you have a weak nitric and want it stronger you can evaporate off some of the water, if you are using it to dissolve metals you can use the dilute acid and heat it with the metal, it will vapor off water as it dissolves the metal, it may take a bit longer but will work just as well or better than a more concentrated nitric will, because the decomposition of the acid is slower and will produce less NOx gases, what gas does form stays in the water making more HNO3, and reacting with the metal, making metal nitrate salts, instead of leaving so easily as those deadly brown fumes.