questions regarding reclaiming nitrates from used solutions.

[au-artifax]

I am hoping that someone can clarify some information I read from the American Chemical Society. In their explanation of double exchange reactions with various nitrate salts in solution, which includes iron, nickel, copper and silver, they state and give the formulas for reactions with nitrate salts and sodium hydroxide, where upon the addition of sodium hydroxide, sodium nitrate, H2O, and the respective metal hydroxide precipitate forms.

My question is, is it worth while to use the left over solution in such a way as to reclaim the sodium nitrate left behind in solution? I tried to find a topic discussing this, but nothing seemed to be specific enough to answer my question. (I did learn a little about handling wastes though). Thanks ahead of time for your ideas and experience. Also, I tried to paste the link where the article can be found and have not had much success. If you search "double exchange reactions" and or "precipitation reactions" along with "American Chemical Society" it may show up.

 

[butcher]

Many times you can reuse the byproducts of chemical reactions, if you can get a separation of the materials or salts, and get the byproduct clean enough for reuse.
Precipitation and solubility's are the key, sometimes you may need to crystallize and recrystallize the byproduct to get a more pure product, depending on its intended use.

 

[au-artifax]

Many times you can reuse the byproducts of chemical reactions, if you can get a separation of the materials or salts, and get the byproduct clean enough for reuse.
Precipitation and solubility's are the key, sometimes you may need to crystallize and recrystallize the byproduct to get a more pure product, depending on its intended use.

Thank you butcher. Having now converted some waste solution to metal hydroxide precipitates and isolating a dilute solution of KNO3, it remains to be seen if it is economical to concentrate the solution enough to the point where I can reuse the KNO3, as that my normal feed stock for synthesizing my NA. Or would it be better to just let nature do it's thing and let it evaporate naturally and not spend time and energy on it as a project in and of itself? I could also I suppose add more KNO3 to the point of saturation and go ahead making my NA. Problem there is I would simply be guessing how much H2SO4 to use, (if I were to use the cold recipe and not distillation).

Sometimes I use the cold recipe for simplicity and throw in a little Ag to remove the sulfates. This I use to dissolve base metals. For AR I use the distillation method. Mostly I do recovery and refining from gold filled items.

 

[butcher]

You could use crock pots to evaporate the nitrate solution, remove crystals as they build up, redissolve them in minimum amount of boiling hot water (to keep the water volume low), and recrystallize the potassium nitrate salts for a higher purity.

 

[au-artifax]

You could use crock pots to evaporate the nitrate solution, remove crystals as they build up, redissolve them in minimum amount of boiling hot water (to keep the water volume low), and recrystallize the potassium nitrate salts for a higher purity.

Thank you again butcher. Does it matter if I use a glazed crock pot vs. a non glazed one, (or am I assuming the wrong thing that the crock pot is slightly porous and aids in the evaporation?)

 

[butcher]

Crock pots are glazed unless damaged, you would not want to use a porous container that would soak up the salts.

They work well for heating solutions, without a lid you can evaporate solutions in them, you will need a way to keep trash like leaves from falling into the pot, like a shelf under a table top, or a cover that will let the gases escape and not form a condensate that will drip back into the pot, I have used a large glass plate from a microwave, and positioned it so gas will escape, condensate formed on the plate would drip into another container sitting next to the crock pot.

This is not the only tool you can use to evaporate solutions, but with the crock pot salts building up on the bottom are not a problem, glassware heated from the bottom can be broken easily if salts build up on the bottom, the salts hold more heat at the bottom of the vessel and the uneven heat distribution can crack the glassware around its bottom, the crock pot uses small wire heating elements wrapped around the outside of the pots, usually two heating elements, for low medium and high heat, switching the current to combinations of the two elements.

 

[jason_recliner]

I am playing with an evaporating idea today for my excessively liquid solutions. I have too much acid, and too much water.

I've taken the top section off an old coffee dripolator I never use. I am estimating (don't have a proper thermometer, and it's only been on for half an hour) that the 750W hotplate only gets the liquid to about 70-80°C or so. Not enough to boil, but hopefully enough to reduce the water.

A wine carton is a perfectly sized cardboard shield to keep today's cool breeze off.

 

[solar_plasma]

I think it has a temperature controller, so you should be fine. I call it Göran's coffee maker, because I first read about this idea in Göran's post. Just be aware of, coffee makers can cause fire, - they are in fact the reason of a lot of fire accidents.

 

[g_axelsson]

I like it!

We got Harolds gold wash, Patnors chip process, Laser Steves acid peroxide process, GSPs wick filtering. And now we also have Görans coffee maker! :mrgreen:

Ironically, I'm a tea drinker. I only drink coffee on more formal occasions or when I'm driving far and need to keep awake. :lol:

Coffee makers have a thermal switch that cuts off slightly above the boiling point of water but since the transfer of heat between the plate and a glass jar (or coffee pan) is rather bad, the liquid in the pan never boils. It's perfect for evaporation and unattended heating of reactions.

Göran

 

[jason_recliner]

I think it has a temperature controller, so you should be fine. I call it Göran's coffee maker, because I first read about this idea in Göran's post. Just be aware of, coffee makers can cause fire, - they are in fact the reason of a lot of fire accidents.

I never saw the post, but saw the hotplates in things like Nurdrage videos. So I will call it Jason Recliner coffee. It's made with a bit of gold, excessive hydro, and way too much sodium nitrate. :mrgreen:

 

[Irons]

You could use crock pots to evaporate the nitrate solution, remove crystals as they build up, redissolve them in minimum amount of boiling hot water (to keep the water volume low), and recrystallize the potassium nitrate salts for a higher purity.

Adding Potassium Chloride to your solution will make it work. Sodium Nitrate is much more soluble than Potassium Nitrate and since there is likely to be lots of Chloride ions in solution, Adding more Isn't going to hurt. Potassium chloride can be purchased quite cheaply as Water Softener Salt. You could start with Potassium Carbonate or Hydroxide, but the additional cost would negate any benefit. Converting Sodium Nitrate to Potassium Nitrate using Potassium Chloride was once a common commercial process, so it does work.

Nitrate Pollution is a consequence that causes problems with Algae Blooms, so removing it from your effluent has additional environmental benefits, even if the financial return isn't much. 8)

 

[butcher]

Another Great tip from Irons.

 

[Irons]

Another Great tip from Irons.

Thanks butcher,

I appreciate the plug.

A little Caveman Chemistry refresher: Wood ashes are a good and cheap source of Potassium Ions. It's just a matter of leaching the ashes with Water and filtering the resulting solution to remove any trash. Don't bother to boil it down and crystallize the salts, just add it to your waste solution and keep an eye n the pH. (6.2 pH for a 10% solution)

From mineral sources

The earliest known complete purification process for potassium nitrate was outlined in 1270 by the chemist and engineer Hasan al-Rammah of Syria in his book al-Furusiyya wa al-Manasib al-Harbiyya ('The Book of Military Horsemanship and Ingenious War Devices'). In this book, al-Rammah describes first the purification of barud (crude saltpetre mineral) by boiling it with minimal water and using only the hot solution, then the use of potassium carbonate (in the form of wood ashes) to remove calcium and magnesium by precipitation of their carbonates from this solution, leaving a solution of purified potassium nitrate, which could then be dried.[3] This was used for the manufacture of gunpowder and explosive devices. The terminology used by al-Rammah indicated a Chinese origin for the gunpowder weapons about which he wrote.[4] While potassium nitrate was called "Chinese snow" by Arabs, it was called "Chinese salt" by the Iranians/Persians.[5][6][7][8][9]

At least as far back as 1845, Chilean Saltpeter deposits were exploited in Chile and California, USA.
From caves

A major natural source of potassium nitrate was the deposits crystallizing from cave walls and the accumulations of bat guano in caves.[10] Extraction is accomplished by immersing the guano in water for a day, filtering, and harvesting the crystals in the filtered water. Traditionally, guano was the source used in Laos for the manufacture of gunpowder for Bang Fai rockets.
LeConte

Perhaps the most exhaustive discussion of the production of this material is the 1862 LeConte text.[11] He was writing with the express purpose of increasing production in the Confederate States to support their needs during the American Civil War. Since he was calling for the assistance of rural farming communities, the descriptions and instructions are both simple and explicit. He details the "French Method", along with several variations, as well as a "Swiss method". N.B. Many references have been made to a method using only straw and urine, but there is no such method in this work.
French method

Niter-beds are prepared by mixing manure with either mortar or wood ashes, common earth and organic materials such as straw to give porosity to a compost pile typically 1.5×2×5 meters in size.[11] The heap was usually under a cover from the rain, kept moist with urine, turned often to accelerate the decomposition, then finally leached with water after approximately one year, to remove the soluble calcium nitrate which was then converted to potassium nitrate by filtering through the potash.

https://en.wikipedia.org/wiki/Potassium_nitrate