Drying chems stored for upwards of a decade. -Potassium Perchlorate -Chlorate -General

[schizojoe]

Howdy folks. first off this could long. as I'm not able to put it in a nutshell and want to be sure to get the data out there that is hopefully needed and can be used to solve this particular puzzle/problem I'm having..

 

I have had some chems for several years.. some as long as a decade or slightly over.. I know that this is not always an issue but things like copper carbonate have seem to be awfully off and slow.. as in burn rate is lacking in some cases or totally seems off (probably do to weight) and ignition is not always easy.. agh that's not what I'm wanting to get at here .. all though it may give insight on the scenarios I've been dealing with..

 

Which I assume is mostly do to the perc and what not being "Dry".. so here we go with some of the scenarios.. name it.. with my KNO3 as I started to mill things things are caking to shit.. not the experience I had several years ago.. but I was never a "Drier" til now as you'll see.. (everything was usually fresh from a source)

 

I set up an outdoor apparatus (an oven in an out building) and have been attempting to get out of this slump and started with about a pound of perc and heated it at 210 ish F (oven thermometer reads a hair over 100 C) for about 2 hours.

 

I guess I should say before hand I took some 5u ind blkhd Al that I obtained many years ago.. and just did a small batch flash test.. just a 7/3 with this perc in question (the only I have at this time) and the results is what I'd consider a sizzle.. not up to par at all for such comp..

 

So this single pound of perc was left to cool and a day or two later.. it did seem substantially better/different.. clumps sifted apart with ease etc..

 

You guessed it.. did another 7/3 with the same chems.. performed as it should.. far from the mere sizzle I was getting..

 

I think what I'm needing to find out is what is "dry" and furthermore what I need to do with my KClO3 that is the same way (and about 8-9 years old) and was/is clumped to hell wouldn't have it..

 

I tried a larger batch.. because I thought it was solved as far as the drying.. of the Chlorate that is.. not the perc..

 

I did it for 2 hours... at the same temps (between 210-215F) but like I say it wasn't all that shallow and was more like 5 pounds..

 

research seemed to show that most don't seem to dry their chems for over two hours (as if that should be all it takes) but then again I didn't nail down the temps too well.. there seems to be a menagerie of them out there.. was looking at a chem forum and this dude baked his KClO3 at 400F .. he didn't really catch hell or anything.. but was just told it may have been too hot.. as he was having trouble with his Chlorate.. which is probably unrelated to my problem. some thought maybe he threw the purity off..

 

As you may assume.. this KClO3 is just virtually unchanged.. I'm just not sure whats in order for me at this point.. I'm a little frustrated.. and I'm not one to rush things or go overly crazy with things in this hobby when in a jam.. for safety sake...

 

In case your wandering about the latency in my chem storage.. it's do to the fact.. I took a tad of a break from pyro here and there.. some years I barely did much.. and for a few.. perhaps nothing at all..

 

I do apologize if I've wasted any ones time.. and I'm trying not to beg for help.. just looking to be slapped straight here.. I'm usually reluctant to ask questions.. but this has grown on me for days now.. kinda got the blues.. motivation is bogging..

 

hope it will be helpful for future if answer do turn up..

 

back to researching..

 

 

TIA

 

- Joe T.

[Arthur]

Everything about your materials depends on how it was stored, and how damp it has become. All of this depends on your annual weather which you haven't mentioned.

 

However a phrase "dry to constant weight" frequently occurs in analytical chemistry. Take some chemical, weigh it, dry it and weigh it again and again until no weight (moisture) has been lost. Be very careful to avoid decomposing chems like chlorate, and be very careful to work separately with oxidisers and fuels and others.

[WSM]

By "Sunshine State" , I'll assume FL? Yes, moisture in things will be a problem.

 

I'm convinced that some oxidizers will clump up and others will grow crystals in humid weather. The nitrate and chlorate can often slow down due to atmospheric moisture dissolving some of it on a microscopic scale and growing crystals that interlock and turn (nitrates especially) into a rock.

 

A solution to the problem is to first dry them out, then break them up to as small as you can and then mill them back to powder. To mill them, most pyrotechnists use a ball mill. The ball mill most use is a rock tumbler with a grinding media. Use heavy media that is non-sparking. I have used ceramic media (alumina or zirconia) or metal (brass, stainless steel, hardened lead [which tends to turn white powders grey, unfortunately], for example). A small coffee mill has been used by some to grind small samples of dried, chunky oxidizers to a fine powder in much less time.

 

Some others have upped their game to using a hammer mill, which if done right is a much faster fix to the problem. A hammer mill can mill in minutes, what takes days to mill in a ball mill.

 

Definitely don't mill mixtures of chemicals, just single materials.

 

The main trick is to first dry the materials thoroughly, next mill it down and lastly put it up in waterproof containers with a good desiccant pack (or use it right away).

 

I hope some of these tips help. If not, see if you can describe the problem differently to help us understand better, so we can offer more useful suggestions.

 

WSM

[Carbon796]

By, ball mill/rock tumbler. Its usually a modified ( to run faster ) HF rock tumbler. For small / test batches. Or a ball mill built with a higher power motor and higher rpm. Based on the thumbler's / rebel 17, 15lb. hex drums. Are the most common. Edited April 19, 2022 by Carbon796

[mx5kevin]

My chemicals are fresh, but I always dry the oxidizers before using and milling. Which is not sensitive to it under the decomposition, and melting point i dry them to get moisture free powders. Working this ways with the chems using a ball mill are fantastic. Powders do not stick and much finer. In Bp and FP, WM, wherever performance matters the method is very good. I refine the chemicals in advance work faster with them this way. I put the chemicals in two bags and seal them airtight. I draw the end of the second to the beginning of the first. It is enough to close it with 2 string the 2 plastic bag. This prevents it from getting wet during storage. This is how they seal the package where i buy my chemicals. After 2-3 years almost same fresh as it was in its new age. There has never been a deterioration in the quality of any of my chemicals. I have 15 year old chemicals. I dry them in a stainless steel pan using a gas stove or a hotplate stirring constantly at low degree.

[mx5kevin]

The KClO3 a chemical that is very need to dry before use. If it is already finely powdered this is very important. If it contains moisture it is much more sensitive, unstable, mixtures with it are can be weaker. Heating under its melting point is good for it before use. If it gets a little wet it is much more dangerous. It does no harm to it to heat below under its melting point.

[mystereas]

Recently moved and found 30 pounds of perc in 2 pound plastic tubs. I'd forgotten about it, it has to be at least 8-10 years old. It was all like concrete. I put a tub in a stainless pan, broke it up and put it in the oven at 200º for five hours. Subsequently screened and ball milled it. Mixed up a small batch of perk and benzo and, POOF!!! the perc still worked great. I want to reconstitute the remaining 28 pounds, BUT, I want to treat it all with Cab-O-Sil. My question is, how much per pound of perc? Thanks in advance.

[Arthur]

Commercial KPerc used to be 0.5% cab-o-sil if it had any additives (some did some didn't).

 

Be cautious of high temperature drying, 15 - 25 degrees over ambient is enough. some compounds will be harmed at over 250.

[WSM]

Commercial KPerc used to be 0.5% cab-o-sil if it had any additives (some did some didn't).

Be cautious of high temperature drying, 15 - 25 degrees over ambient is enough. some compounds will be harmed at over 250.

 

 

To be conservative, I'd say 0.1-0.5% Cab-O-Sil (fumed silica) would work, depending on your atmospheric and storage conditions. Heating most oxidizers (first, search individual oxidizer data online to understand its physical characteristics ) can be safely done above 100^oC and less than 170-200^oC. Heating them in a thin layer on parchment paper (maybe, or possibly something assured to be non-reactive) on a wide pan would probably work well. Try doing so for about 2 hours with occasional stirring and see if that helps.

 

Good luck.

 

WSM

[schizojoe]

Hey guys..! been a while huh?..

 

I really appreciate the feedback it has helped tremendously. I still have some questions and theory I'd like some input on. For one I do like the hot plate approach over the oven.. all though I can't say exactly why. it is more of a preference I think.. and I don't like the oven.. and accessibility in manipulating the contents (chemical) occasion seems easier.. 

Here's where I want some input.. the fact I think my chemicals are dry which at this point I've only really made full attempts at oxidizers KCLO3 and 4..  I'm curious of how damp my chems were and how I can in fact tell they are pretty dry or atleast dry enough to be "up to par" for say FP or other dry comp that's used as is.. gerb formula for example which still burns slow in my view.. but it just may be the ingredients I'm using with the main oxidizer being the perc.. that has been dry..

These are some observations I had.

As the perc was drying it become lighter in shade of color and starting to become airborne as the drying went on. I'm assuming this is on track and that my perc was relatively damp to say the least?

second I may add that I did have to lower the heat  (via hot plate) to pretty low but hot enough.. I had some sticking.. I'm assuming this was likely the high temp and the fact that the perc was treated with cab o sil?.. and just learning that the temp doesn't need to be too high anyway.. and I'm pretty patient person.. 

On that note.. I wanted to y'all to be aware of what I'm working with as far as my particular perc... This perc was purchased long ago.. and originally it came in the consistency of sugar.. it was share by someone who said it was 99.9 or so and it was made for NASA and they were sharing.. perhaps someone remembers this going around and it selling. but that's not what I'm getting at.. 

The perc was milled by me way back a decade ago like in the original post. I added cab o sil to it each batch I made.. while it never "caked" after all this time it still was pretty damp and to extent not very usable IMO.. Could this pose an issue with the perc and drying? as in too much cab o sil.. If so is there I fix other than adding perc which I'm not going to chance or do for that matter.. and would too much cab o sil cause issues.. which I think I'm learning now in regards to the semi recent follow up posts in this topic..

I'm going to have to cut short now.. if there's any details needed just let me know and I'll follow up when I get a second.. 

 

sorry but running a bit short on time as of writing.. and gotta tend to some projects.. I appreciate any comments and feedback...

PS:

I am the OP and yes I'm in Florida

 

Thanks again.. 

 

         Joe..