16 replies to this topic

[StevenRS]

When purchased from chemical supply companies, most chemicals are very pure. But this is expensive, and takes time (plus you get put on "lists"). Many chemicals are available at the local gardener's or hardware store, but at low purity. (90%dusting sulfur, potassium nitrate weed killer) Could it be possible to fairly easily purify these chemicals available locally?

[marble]

kno3 is easy, dissolve it in hot water, cool down and filter the pure crystals out

[BigG]

The simple answer is no. Procedures for purifying chemicals are being invented and re-invented all the time. Purification depends very much on the chemicals that are considered the “contamination”, and their properties compare to the chemical we are trying to purify. Marbles answer (the one above this) is poor as it suggest that KNO3 solidifies before other chemicals, and there are quiet a few chemicals that will come out before KNO3.

Purification and how easy it is totally depends on the mixture you are trying to purify. There is no – "one fit all solutions", and indeed, some chemicals are so hard to purify that the finished purified product fetch amazing price.

Edited by BigG, 30 April 2007 - 10:28 AM.

[StevenRS]

I am not talking about reagent grade, just acceptable quality. For example, how would one remove some of the 10 percent of impurities in fertilizer grade dusting sulfur?

Maybe you could evaporate it and condense it, or something along those lines.

[BigG]

I am not talking about reagent grade, just acceptable quality. For example, how would one remove some of the 10 percent of impurities in fertilizer grade dusting sulfur?

Maybe you could evaporate it and condense it, or something along those lines.

Again, this depends on the other chemicals in your mix!!!

for example, Sulfer is Insoluble in water, so you can mix it with very hot distilled water – and IF the other chemicals are soluble, you can filter the liquid out with the other chemicals, leaving a purer Sulfur. However, if the other chemicals in the mixture are not soluble – this will not work…. You NEED to tell us what are the other chemicals mixed with the sulfur.

[EnigmaticBiker]

I am not talking about reagent grade, just acceptable quality. For example, how would one remove some of the 10 percent of impurities in fertilizer grade dusting sulfur?

Maybe you could evaporate it and condense it, or something along those lines.

I agree entirely with what BigG is saying.

As a pointer, you could go online and find a data sheet for your product and/or a patent if applicable.
Then work out what components are soluble and what to dissolve them in.

Here's one link to a solubility chart and calculator:

http://www.saltlakem...ility_Chart.htm

This is not as simple as it sounds, in the case of water soluble salts, the relative solubilities at different temperatures will greatly influence which crystals appear at different points.

[StevenRS]

Sadly, I never was able to find out exactly what was in my sulfur, but whatever it is, it is water soluble, probably a sulfate. I ran near-boiling water through it, and the water assumed a grayish color, and upon evaporation, left a gray, powdery, slightly crystalline residue.

After this treatment, the washed sulfur burned visibly better, thanks.

I also washed it with a variety of other solvents, but to little effect.

Edited by StevenRS, 03 May 2007 - 12:50 AM.

[Mumbles]

The 10% contamination is mostly clay. I've heard you could just add the dusting sulfur to water and one would eventually sink, and the other would float. I don't know how much truth there is to it though. Some clays can be dissolved by HCl. The sulfur won't be affected, but it may yield you acidic sulfur in the end.

[BigBang]

If we are discussing sulphur and kno3 (which incidently is a fertiliser not a weed killer, sodium chlorate is the weedkiller), you can easily and cheaply buy these in pure enough form, to use in pyro. In actual fact, they are the 2 cheapest and easiest to obtain chems, used in pyro!

[Andrew]

GOLD?

[StevenRS]

If we are discussing sulphur and kno3 (which incidently is a fertiliser not a weed killer, sodium chlorate is the weedkiller), you can easily and cheaply buy these in pure enough form, to use in pyro. In actual fact, they are the 2 cheapest and easiest to obtain chems, used in pyro!

Yea, but buying 20 pounds of fertilizer grade sulfur for 5 dollars beats ordering it any day....

[EnigmaticBiker]

GOLD?

Er?
Panning reference?

[BigBang]

Yea, but buying 20 pounds of fertilizer grade sulfur for 5 dollars beats ordering it any day....

Youre getting slightly confused. KNO3 is the fertiliser not sulphur. Fertiliser grade kno3 is OK for pyro use, and is cheap....very cheap! So is sulphur.

[Mumbles]

Sulfur, as dusting sulfur has it's uses in agriculture. Mainly in rose gardening I do believe. Has 10% or so clay, but still works fine so I am told.

[BigBang]

Personally i use 'flowers of sulphur' which i 'wash' (as described in a different thread) to remove the trace amounts of sulphuric acid. It works out extremely cheap, about £2kg!! and gives great results. This type of sulphur is used as a soil additive, (to acidify it).