tiggertree
Member
I cannot see any reference to magnesium nitrate in the thread.
Sodium nitrate..
- Thread starter Clephane
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Why do you want to use Magnesium Nitrate in the first place?
I guess Calcium, Sodium Potassium Nitrate is easier and cheaper to find.
Besides that any Nitrate should do the job.
Balance it and go ahead.
I guess Calcium, Sodium Potassium Nitrate is easier and cheaper to find.
Besides that any Nitrate should do the job.
Balance it and go ahead.
tiggertree
Member
I have a 25kg bag I have no other use for.
It is 11% nitrate. So by my estimations 300gm per 100mm of distilled water.
It is 11% nitrate. So by my estimations 300gm per 100mm of distilled water.
Very low concentration.
Only one way to find out, but still, I’d save my Sulphuric for some good quality Nitrate.
lazersteve
Well-known member
If you feel like converting it to the more desirable NaNO3 (due to higher molar solubility: Na=10.7M whereas Mg=9.6M =moles of available nitrate per liter @25C; also Na salt is less hygroscopic) you can do so via:
Na2CO3 + Mg(NO3)2 --> MgCO3 + 2NaNO3
Use a minimal amount of water to make saturated solutions of each starting compound and mix with copious stirring. Allow to settle and pour/siphon off the resulting NaNO3 solution from the MgCO3 solid. Use cold water rinses on the sludge in the bottom of the reaction vessel and evaporate the filtered wash liquids with gentle heat until the wash solution saturates. Add all clean and clear saturated NaNO3 solutions together and proceed as described in the original recipe.
Use the MgCO3 to neutralize waste solutions.
Do a small scale test to determine the starting water content of you Mg(NO3)2 as it likely contains water weight absorbed from the air. Typical Mg(NO3)2 that has be exposed to open air can be as high as 6 moles of water per mole of nitrate.
It's a bit of a task to convert 50#, but it works to get you to NaNO3 if that's what you want to do.
If you you decide to just go with the Mg(NO3)2 as is in the recipe do your homework and determine the amount of water that is present in your starting material so you don't mess up your math. At 6 moles of water per mole of Mg(NO3)2 you will have (6×18= 108g ) 108g of water weight per mole of nitrate used. This works out to ~518g of nitrate mass error if doing a liter (4.8 moles of Mg(NO3)2 is soluble in 1L H2O)
Steve
lazersteve
Well-known member
The only factors that I can think of off the top of my head that should adjust your numbers are:From the man himself, saved me from buying lots of expensive nitric... thanks
Is your calculations for the nitric still standing or is there any adjustments we should make for better results.. thanks
-Water content of nitrate used
-concentration of sulfuric acid used
-temperature at which you dissolve the nitrate.
I might also add that a second 4-6 hour freeze cycle can produce a second batch of sulfate crystals. This isn't necessary if you use the calcium nitrate to scavenge the remaining sulfate.
Steve
lazersteve
Well-known member
You can use the carbonate conversion reaction I cited above to get a decent idea of your starting nitrate percentage by mass.
Perform a small scale conversion and weigh the resulting dry MgCO3 yield. From this information you can closely determine your starting nitrate content .
1) Be sure to accurately record the starting weight of your test sample before performing the test.
2) When drying use a target temperature greater than 165C and less than 200C to avoid decomposition of the core carbonate compound. Your goal is only to dehydrate it completely.
3) Once you have dry carbonate simply weigh the total product to +/-0.1g and divide the mass by 84.3g .The result is the number of moles of Mg(NO3)2 in your starting sample weight.
4)Try to avoid losses in the sample along the way. These can be spills, transfer losses, rounding errors, among other things.
I hope this helps,
Steve
tiggertree
Member
Thank you for the detailed instructions.
I will put it into practice.
I will take notes and post my results.
I will put it into practice.
I will take notes and post my results.
William656
Member
Awesome. I was wondering the same thing. Do you have any notes you can share by putting this into practice? Thanks!
