Guessed why my blues were washed out.

[50AE]

So the story first.

 

Last year, I remember when I've made my very first blue, and it was very deep and cool! I loved it. It was made with KClO3, which I made by electrolysis.

 

The formula was:

 

66,5 KClO3

13,4 CuO

9,9 Red gum

5,4 Parlon

4,8 SGRS

 

But, the potassium chloride used for the electrolysis of the chlorate was very expensive, because it was laboratory grade clean, 99,5%.

I bought fertilizer grade KCl then.

 

The next year, I made the same formula, but with dextrin instead of SGRS.

The Blue was very inferior, pale blue and kinda purplish.

I thought dextrin was the cause, so I replaced it with SGRS again. Then again with gum arabic.

Then I tried another formulas. I also tried gum arabic, shellac, copper oxychloride, etc.

Still washed out! Ugly, light blue

 

This week I decided to switch to the "dark side". I made a test batch of chlorate sulfur composition with copper oxychloride and binder. The flame was much cleaner than this with organic fuels, but...

IT WAS STILL UGLY! I mean, it's nice when looked at close distance, but from long distance it's washed.

It was not as my first lovely blue.

 

Then I was thinking, thinking, thinking... What could be different? What have I changed?

Oh yeaah! I've changed my potassium chloride source, could the fertilizer grade be contaminated with sodium?

 

I opened my chemical supplier catalogue.. No information about the fertilizer, but good information for the technical grade - 97% purity, NaCl 2%.

Logically, fertilizer grade should be inferior than technical grade, so NaCl contamination could be worse.

 

So, it seems my KClO3 is Na+ contaminated enough to wash my blues.

And I really want to have a good blue for NYE, because it's my best friend most favorite color.

 

I have to decide.. Should I do a new electrolysis with pure KCl, or doing two recrystallizations of the present KClO3 with destilled water will do the job? What do you think?

Edited November 22, 2010 by 50AE

[AdmiralDonSnider]

Interesting info, but mate, do you really care making your own chlorate? I mean it´s not pricey at all.

[bikemaster]

What was your purification process?

Even with fertilliser grade, you can purify it to get almost no NaCl.

[50AE]

Chlorate is very pricey for me. If I make it my own, there's a reason.

 

My purification process was single recrystallization and then a slight wash with ice water.

[bikemaster]

Before recrystallizatio (after you have disolve the salt) did you filter the hot solution?

How fast was your recrystallization?

Did you put let it become to room temp before put it in the cold?

Because slower recristalisation is much better.

 

If you did all those thing, try and other recrystallization with a small batch and try a star with it.

[Mumbles]

I'm a little suspicious about you thinking it's sodium causing your problems. Sodium doesn't wash colors out, it turns them yellow, even a minuscule amount. I'd try purifying some of your chlorate with one or even two more crystalizations before thinking your problems are solved. It's a little premature to think you're in the clear without first having a solution.

 

Honestly, I'd try recrystallizing the starting chloride before you electrolyze. Sodium and potassium chlorides are a lot easier to separate than sodium and potassium chlorates. A flame test on your chlorate will also tell if there is really sodium in there.

 

Have you ever tested your chlorate for chloride content? I'd think that'd be more likely to purely wash out a blue flame, as opposed to turning it a different color. It also makes chlorate compositions more sensitive.

[50AE]

You may be right about the Na+ characteristics, though I'm pretty sure impure KClO3 is the reason. It could be KCl as well, if it washes colors.

 

A flame test on my chlorate showed negative. It wasn't really good lab flame testing, just a needle with a KClO3 crystal over an alcohol blue flame in the dark. Didn't show yellow though.

 

About the recrystallization. Yeah, last week I read in a chemistry manual that recrystallization should be done at slowly cooling temperature. I did it that way. I'm gonna do it again with distilled water and then I'll tell you if blues are better.

 

Here are some shots of blues:

 

My first lovely blue

 

Forli blue (bad chlorate)

Forli blue on ground

Sulfur chlorate blue on ground

Sulfur chlorate blue on ground 2

 

Haven't tested my batches for KCl since some time though. I should start to do that for every new batch i synthesize.

Edited November 23, 2010 by 50AE

[FREAKYDUTCHMEN]

I'm a little suspicious about you thinking it's sodium causing your problems. Sodium doesn't wash colors out, it turns them yellow, even a minuscule amount. I'd try purifying some of your chlorate with one or even two more crystalizations before thinking your problems are solved. It's a little premature to think you're in the clear without first having a solution.

 

 

That is incorrect.

 

The yellow spectrum is the opposite of the blue spectrum. 2 opposites makes white light. Sodium is a very strong emitter of yellow light. So a little bit of sodium in your KClO3 washes the blue out very easily.

[Bonny]

You may be right about the Na+ characteristics, though I'm pretty sure impure KClO3 is the reason. It could be KCl as well, if it washes colors.

 

A flame test on my chlorate showed negative. It wasn't really good lab flame testing, just a needle with a KClO3 crystal over an alcohol blue flame in the dark. Didn't show yellow though.

 

About the recrystallization. Yeah, last week I read in a chemistry manual that recrystallization should be done at slowly cooling temperature. I did it that way. I'm gonna do it again with distilled water and then I'll tell you if blues are better.

 

As Mumbles suggested, test your chlorate for chloride ( I use silver nitrate). After I harvested my (potassium) chlorate chrystals, they were drained and given at least one, sometimes 2 hard washings with ice cold distilled water. At that point some batches still tested positive for chloride, but the crystals were then re-crystalized and given a final washing...no chloride detected. When I recrystalize, I filter the solution through coffee filters and allow to cool for several hours before chilling, as recommended above.

[50AE]

I also wonder if newspaper paper contains sodium, because the last batch of KClO3 has been dried on newspapers.

[Updup]

I also wonder if newspaper paper contains sodium, because the last batch of KClO3 has been dried on newspapers.

 

I think they use sodium hydroxide in making paper... Could be wrong though

[Bonny]

I also wonder if newspaper paper contains sodium, because the last batch of KClO3 has been dried on newspapers.

 

 

I dry mine on plastic trays or in a shallow plastic tub.

[50AE]

When shooting the stars (sulfur with dirty chlorate) from a starmine, the color was a very beautiful dark violet.

But now when trying the same formula using the purified chlorate, the color is a very nice blue. On ground, it appears somewhat washed out, but it's very beautiful in the air.

It seems KCl really does impact the color in the purple spectrum.

Edited December 1, 2010 by 50AE

[pdfbq]

Honestly, I'd try recrystallizing the starting chloride before you electrolyze. Sodium and potassium chlorides are a lot easier to separate than sodium and potassium chlorates.

Hi Mumbles,

Could you explain why? Because the data I have says that 100ml water can contain 101.0 g NaClO3 at l (20 °C) and the graph I have about KClO3 looks like this:

I am no chemist so forgive me if I say something stupid but to an amateur this looks like an ideal recrystallization scenario.

[Mumbles]

It's because of the sodium chloride actually. It has the interesting property that it's solubility changes very little over temperature. With the low solubility of potassium chlorate at low temperatures, I'm not sure that chlorate separation is actually harder. You'd certainly get better yields with chlorate. I'm used to doing crystallizations from saturation, and was kind of assuming that both compounds would be saturated. Thus you'd get much less contamination with chloride vs. chlorate. We all know where assuming leads us though.

 

On second thought, as long as the product is primarily potassium chlorate, it shouldn't be to hard to purify by crystallization. It still may require two go arounds to get everything clean though.

 

I suppose a very small amount of sodium could in theory wash out a blue, but even that amount would show up in a flame test.

[taiwanluthiers]

I don't see how agricultural grade KCl would contain sodium chloride. I worried about this because I use that too (I have to dissolve/recrystalize them at least once because it comes with red stuff that is real fine). But then I read someone said that sodium is bad for plants so there's no way they would put sodium in agricultural products.

[Mumbles]

2 words, chilean saltpetre.

 

If you have any sodium chloride in your potassium chloride stock, it will likely stay that way. Any sodium chlorate formed will instantly be precipitated by the potassium chloride to form potassium chlorate, and sodium chloride again.