Meal? Green Mix? What?

[dagabu]

I don't want to get flamed for starting another topic in the forums so i ask here.....

Pulverone, meal, granulated. I'm lost with the procedure for each. The only one I think I have down is Green mix. Being all 3 put into a ball mill and ran for 3-6hr (dry/wet...not sure either), would produce what? Meal, pulverone?

I've been what I think to be conflicting info on the subject...i'm pretty sure it's do to me though, so clearification is needed on my part.

I'm also confused with the term(s) granulated, riced, and corned. Maybe I'm looking like an idoit now because of lack of exper., but I really do read alot on the subject, and I'm at the starting stages of putting all together.

I read that riced...(is pushing BP, through a screen). However what size screen is used to produce "Rice"? If i'm using a screen then wouldn't that mean i'm simple just Granulating at whatever size mesh of screening I'm using? And "Corned" being the same as "Grantulated" however to be "Corned" first...(ROFLMAS), your BP must be pressed?

How I'm I sounding so far....?

 

OK,

 

Its an age old question so I will take it from Mike Swisher, the oldest living pyro-nut... OK, not the oldest but perhaps the smartest.

 

Starting at the least reactive and working up to the most difficult to make:

 

1. Green Meal or Rough Mix

-Green meal is the simple combination or all three pre-ground chemicals, typically 75:15:10.

 

2. Pulverone

-Pulverone is the mixture of all three chemicals, adding enough boiling water to make a cohesive (will stick together in a ball) ball of the comp and then is pushed through a screen, usually a 3 mesh, and left to dry half way and then re-screened.

 

3. Milled BP

-Milled powder is made by milling all three chems together in a ball mill until a homogeneous mixture is created. With the addition of 2-4% dextrin and cool water, the cohesive ball is mad and is pushed through a screen just like pulverone. The performance is much greater then the pulverone and can be much greater then commercial BP.

 

4. Pressed and Corned Black Powder.

-Pressed and corned black powder is the standard BP that you find in cans all over the world. It is made by following the same procedures as the milled BP but instead of adding dextrin, just a small amount of water is added, the BP is pressed into pucks to 1.7g per square inch and then the pucks are broken and screened into different meshes. Some BP is them tumbled with graphite to make it flow better.

 

TERMS:

 

-Ricing: To push the ball through a screen when wet.

-Granulating: See ricing.

-Corning: Breaking up pressed pucks of BP into smaller pieces of BP.

-Meal-D: Small pieces of broken BP pucks that are smaller then 7FA, also called Meal Dust by some, but that is a whole other conversation...

[Mumbles]

One quick correction. The BP is pressed to 1.7g/cc, not g/sq.in.

[kiss]

Thanks Dagabu...

That helps abit. Bare with me alittle more though.

When i'm able to get my ball mill running, would i simply put all 3 in (Green mix.....+2-4% dextrin,water), and have at it for afew hours? Upon taking this out afterwards this mix is now considered Meal D BP?

At the moment, my main concern is Meal D because it seems like a logical step. I see people using this for coating grass seed, rice hulls, and some vid's show rice hulls for lifting small shells, not to mention burst charge. This sound right?

When i feel confident enough with that I'd like to move on to ricing.

 

 

[Mumbles]

I'll see what I can do with the plan you've outlined.

 

Firstly, don't add water to the mill. You'll end up with a caked mess.

 

When the product is removed from the mill, it's not Meal-D just yet. It would be considered mill powder or meal powder.

 

To get true meal-D, you'll need to wet and press your powder. Break up the granules. Whatever passes 50 mesh is considered meal-D. Luckily you can always crush further, so you can make a much meal-D as you'd like.

 

For what it's worth, most people just use meal powder to coat rice hulls and stuff.

[dagabu]

One quick correction. The BP is pressed to 1.7g/cc, not g/sq.in.

 

DO'H!

 

I knew we kept you around for something. Care to give an update on how you are doing?

[kiss]

So even Meal D gets pressed huh? I guess in the case of meal d your not really after 1.7g/cc right? It wouldn't make a diffrence right?

Ok lets see if i have this correct....

all 3 go into a ball mill...(dry/no dex), after x amount of hr's the mix is meal powder/mill powder. To obtain meal d, this same mix must now be wetted, and pressed, or can you ball this up and pass it through the mesh?

If this must be pressed just how long does it stay under pressure? Till bone dry?

[AdmiralDonSnider]

So even Meal D gets pressed huh? I guess in the case of meal d your not really after 1.7g/cc right? It wouldn't make a diffrence right?

Ok lets see if i have this correct....

all 3 go into a ball mill...(dry/no dex), after x amount of hr's the mix is meal powder/mill powder. To obtain meal d, this same mix must now be wetted, and pressed, or can you ball this up and pass it through the mesh?

If this must be pressed just how long does it stay under pressure? Till bone dry?

 

The milling process is correct as you described it. Meal D is corned gunpowder passing 40 mesh; corned gunpowder shows a density of 1,7g/cc - so yes, it does make a difference. (It is pressed (with sufficient dwell time) until it has reached the desired final density - then the cakes have to be dried for about two days.) Hand granulated gunpowder (pulverone) is nowhere that dense; this makes a difference in some applications, e.g, fountains, special stars. Furthermore meal D actually partly is grain gunpowder; this has an influence on its burning characteristics.

 

There are many applications where meal powder and meal D are practically interchangable. However, some do specifically call for the latter and riced gunpowder (pulverone) will be an inferior replacement in these cases.

Edited September 29, 2010 by AdmiralDonSnider

[Bonny]

The milling process is correct as you described it. Meal D is corned gunpowder passing 40 mesh; corned gunpowder shows a density of 1,7g/cc - so yes, it does make a difference. (It is pressed (with sufficient dwell time) until it has reached the desired final density - then the cakes have to be dried for about two days.)

 

The cakes (or pucks) can be crushed/broken while still wet. I have not noticed any change in performance when crushing them wet or dry.

[dagabu]

This is one of those times when there are several correct answers to your question, ask ten pyros and you will get eleven different answers.

[Mumbles]

I've actually heard from some people that they tend to get less fines when breaking the pucks up while wet.

[dagabu]

I've actually heard from some people that they tend to get less fines when breaking the pucks up while wet.

 

Obviously, I can only speak from my limited experiences here but I found that when corned while still fresh, the pieces would burn faster then if I had let it dry out first before corning the pucks. I shared this with a chemical engineer and he took a chunk of commercial, dry corned BP, the fresh corned BP and looked at them in a microscope.

 

What he showed me (pictures) was HUGE surface differences. The graphite milled BP (commercial) was relatively smooth while the dry corned BP has a lot of hills and grooves and the wet corned BP looked like a seismic graph! Lots of spikes and deep valleys, lots of places to catch fire.

 

I tumbled a few hand fulls of the wet corned with some graphite and the spikes all went away and the powder slowed considerably.

 

This is not directly related to the issue here but I thought I would share.

[Algenco]

Obviously, I can only speak from my limited experiences here but I found that when corned while still fresh, the pieces would burn faster then if I had let it dry out first before corning the pucks. I shared this with a chemical engineer and he took a chunk of commercial, dry corned BP, the fresh corned BP and looked at them in a microscope.

 

What he showed me (pictures) was HUGE surface differences. The graphite milled BP (commercial) was relatively smooth while the dry corned BP has a lot of hills and grooves and the wet corned BP looked like a seismic graph! Lots of spikes and deep valleys, lots of places to catch fire.

 

I tumbled a few hand fulls of the wet corned with some graphite and the spikes all went away and the powder slowed considerably.

 

This is not directly related to the issue here but I thought I would share.

 

 

yep, "polished" with or without graphite is slower for the the reasons you stated

Graphite coated is the slowest