Making strontium nitrate

[NeighborJ]

I'm planning on making some strontium nitrate from either calcium nitrate or magnesium nitrate. I am calling upon people with experience making this. I have both strontium carbonate and strontium sulfate available but I'm not sure which would be the better option for this reaction. I wish to make comparisons to my comercialy available supply.

How have others made it?

[greenlight]

I have always made it from strontium carbonate and 70% nitric acid.

45 grams strontium carbonate in 100ml water and drop in 20 ml HNO3 making sure it doesn't fizz over.

If you don't have nitric acid surely potassium or ammonium nitrate would be a better salt to use than calcium or magnesium but I could be wrong.

[memo]

nj

i would also like to make strontium nitrate. if you come up with a fairly east process keep me up to date. like so many things used in pyro I cannot buy here in a powdered form.

[NeighborJ]

Green light, the reason I am not using KNO3 or ammonium is because their carbonates are soluble in water and won't precipitate out of solution, but calcium carbonate will. I don't have nitric acid but the calcium nitrate is commonly available and cheap-$26 for 50#. I lucked out and found both barium carbonate and strontium carbonate at a local ceramics supply house for sale at a good price. I believe I can make both nitrates cheaper than I can buy them.

Memo, indeed I've found an easy method for making strontium nitrate and it involves using ph test strips to determine which chem to add to complete the displacement reaction. I don't make solutions of each chem but rather mix them dry and only add enough water to keep the resulting nitrate in solution by crossreffrencing a solubility chart. Once all the chems have reacted I check the ph, if it is above 7 I add more calnitrate and if it's low I add more carbonate.

Once balanced at 7 the solution is decanted off thru a filter and then allowed to dry.

[PIL]

Calcium nitrate is neutral,so your ph test strips may not work.Furthermore,strontium carbonate is even less soluble than calcium carbonate,which makes the convertion very troublesome.

Let's find another way to shift the equilibrium.For ammonium carbonate or bicarbonate have low thermal stability,this reaction may happen in a boiling hot solution. Never overheat Ammonium Nitrate!

2NH4NO3(aq)+SrCO3(s)=Sr(NO3)2(aq)+CO2(g)+2NH3(g)+H2O(l)

Excess SrCO3 is filtered out when hot to obtain a clear Sr(NO3)2 solution.

If you can have access to nitric acid ,try treating SrCO3 with nitric acid ,the process will be simple and safe.

[NeighborJ]

PIL, yes the calcium nitrate should be neutral and when I made the sodium nitrate in this manner I made a solution heavy with soda ash and added the calnitrate slowly until it just reached ph7. I didn't really experiment to see if it could reach into the acidic spectrum, thou I did overshoot once to a ph of 6.5 once so maybe my nitrate is slightly acidic? My theory for the lack of solubility of SrCO3 revolves around the fact that the CaNO3 will react with the small amount of SrCO3 which did disolve which will leave room for more carbonate to dissolve and react. It takes a little bit of stirring but it worked and all the carbonate reacted eventually w/o heat.

[NeighborJ]

OK I've done some more research. The strontium carbonate will not react with the calcium nitrate but the strontium sulfate will produce strontium nitrate. I'll need to look for a supplier of sulfate at a reasonable price. I'm just not comfortable making or using HNO3 without the proper equipment thou it is probably the easiest way to make it.

[OldMarine]

What would you need to make the nitric acid? I've got a fairly large collection of lab glass.

[NeighborJ]

The nitric acid is used to react with strontium carbonate to make its nitrate. I don't yet have that kind of lab equipment needed nor the know-how to use it all. Thou I can find you tube vids showing me if I want to trust them.

I'm just looking for a double displacement reaction of cheap and accessible chems which won't burn my skin off if it spills on me.

[OldMarine]

Nitric acid is easy to make with simple equipment as long as you're not too worried about purity. I can use 2 beer bottles and a can of sand to make passable acid but for a more pure product a decent condenser and a method of heat control is needed.

[NeighborJ]

I watched the nerdrage you tube video and for the pure stuff they used bits of cu,HCL acid,calcium nitrate,H2O in ice and a glass condenser. It would make HNO3 but it's a small setup and doesn't seem like it could make much SrNO3. It does look like fun.

[Mumbles]

Strontium sulfate is also less soluble than calcium sulfate. Not going to work.

 

Your legitimate choices are ammonium nitrate + strontium carbonate (pretty slow and smelly btw), nitric acid + strontium carbonate, or just paying the $4-5 that it costs and skipping all the hassle.

[NeighborJ]

From what ive read about the strontium sulfate is that it becomes less soluble as temp increases and there are some forms of alcohol which will cause it to precipitate from solution. This process wouldn't make it viable even if the strontium sulfate could be purchased at a good price. And Mumbles you are correct it is easier to use the stuff i bought as it will last me a year or so. Its the process which has caught my intrest and not so much its use. Edited January 8, 2017 by NeighborJ

[OldMarine]

I'll be the first to admit that although I probably have more labware than some chemists I have almost zero knowledge of the subject. I have a few processes I perform by rote and that's it. I really enjoy reading of other's experiments (ie; WSM's perchlorate /chlorate threads) and hoping I'll learn a bit from them. I love any time I can add a bit to help them and have been lucky enough to do so a couple of times.

Please don't get annoyed at my questions and I'll promise to keep them to a minimum!

[NeighborJ]

You are no bother OM, I certainly dont know much and have been researching everywhere but as it turns out there is a lot of bogus crap on the web making claims and showing patents to back them up. Im the fool for thinking one of them may provide fruit. I guess this experiment will need to wait for warmer weather so i can use HNO3 outside.

Does anyone know the expected yield of SrNO3 from a 4oz bottle of 67.5% HNO3. I just want to get a guesstimate of the cost from a known quantity.

[Seymour]

I don't know of yield from a known amount of acid, though I know it is calculable.

I always just chucked some water in an HDPE bucket, threw in some acid, and scooped carbonate in, stirring in between scoops until the bubbling stopped, and adding scoops like this until the addition of more carbonate does not cause a reaction.

The contents are then filtered, and recrystallised to whatever extent necessary, which really depends on end use and carbonate purity. For most uses I've found the first crystallisation of Barium or strontium nitrate to be usable.

[Differential]

The yield of Strontium nitrate from nitric + Strontium carbonate will be nearly 100%, if you do it right. You slowly add acid with stirring until the mixture stops bubbling.

4 fluid ounces of 67.5% will weigh about 5.6 oz, and contain 107 grams of HNO3 (1.70 moles). You need to add it to slightly more than 0.85 moles (126 grams) of Strontium carbonate (so the carbonate is in slight excess). You should end up with 0.85 moles of Strontium nitrate (180 grams).

 

But I think the cost and hassle of nitric acid will be more than the cost of just buying strontium nitrate. It's not cost-effective to make most nitrates this way, unless you're looking at lithium nitrate, which I could only find as medical or reagent grade.

 

If you're going to make your own nitric acid, I wouldn't recommend the "two beer bottle and sand" method above, whatever that is. Beer bottles are poor quality, and can easily shatter with heat. Get quality borosilicate glassware, hot plate w/ magnetic stirrer, and do it outside or in a fume hood.

Edited January 16, 2017 by Differential

[Differential]

^{Not sure if this would work well, but you might try adding a solution of strontium chloride (which you could make with industrial hydrochloric acid and strontium carbonate) to a solution of potassium nitrate. The resulting potassium chloride should have a lower solubility than the strontium nitrate.}

Edited January 16, 2017 by Differential

[NeighborJ]

Diff, I am aware of that last method but I had dismissed it as a possibility because I didn't think I could remove enough of the KCl contaminants from the solution. But now I'm wondering if there is another solvent which can be added to the final solution which can allow either SrNO3 or KCl to precipitate enough to yield a relatively pure product? Just thinking out loud, maybe denatured alcohol, of coarse chilling the solution will help.

This is purely an educational experiment and I realize it isn't cost effective but I seem to learn better when I can put my hands and eyes on the project. I don't yet have the proper equipment to make HNO3 so Id like to avoid trying it until I do and ill need some warmer weather so I can do this all outside without a fume hood.

Thanks for all the suggestions guys, I've got some more research and studying to do.

[Richtee]

I used to just soak road flares in water, filter and evaporate. But..I suppose it’s not PURE Sr(NO₃)_2.

[EdM]

Mumbles' assessment of the two viable methods is spot on. The first is certainly safer, barring overheating of solid ammonium nitrate. If you can't get ammonium nitrate, you can make it from ammonium sulfate (available as an agricultural product, usually as a solution) and calcium nitrate in a double displacement reaction; the calcium sulfate will precipitate. Ammonium Nitrate is notoriously highly soluble. Chill the solution for the most complete precipitation. An alternative source of ammonium sulfate is, of course, the reaction of sulfuric acid (battery, rooto) and ammonia (household, janitorial, new or used blueprint developer). It's potentially possible to recycle the ammonia by capturing the gas in ice water as it is evolved. So Strontium Carbonate (cheap), Sulfuric acid, (cheap) and Calcium Nitrate (cheap) are all the sources you need.

[greenlight]

@Richtee...You would have probably got a small amount of potassium perchlorate or potassium nitrate dissolved as well.

Did you still get nice reds from compositions using it?

Edited March 24, 2017 by greenlight

[Richtee]

@Richtee...You would have probably got a small amount of potassium perchlorate or potassium nitrate dissolved as well.

Did you still get nice reds from compositions using it?

 

Excellent reds

 

On Edit.. Crappy vid... but..

Edited March 24, 2017 by Richtee

[PyroDanTheMan]

For my fellow pyros in the US. Duda Diesel has nitric acid for sale. Have done business with them and will again. Bought sulfur and potassium nitrate and have no complaints.

[WSM]

For my fellow pyros in the US. Duda Diesel has nitric acid for sale. Have done business with them and will again. Bought sulfur and potassium nitrate and have no complaints.

One main sticking point may be the quality of the strontium carbonate. If you can locate reagent grade material, you're golden; but if you're working with ceramics grade chemicals, I'd strongly recommend purifying it first.

 

WSM

Edited April 17, 2017 by WSM