Sciencemadness Discussion Board

Why is my sulfur metal mixtures not working well?

KonkreteRocketry - 3-4-2013 at 12:31

I tried Sulfur with magnesium and zinc for flash powders to see if they work, but with zinc it dosent even burn, and with magnesium, barely. why is it ? I tried Nitrate-Magnesium and the flash was really really great, but isnt sulfur and magnesium or zinc some good flashes also ? why does it work very bad for me ? any one had experience in those ?

Adas - 3-4-2013 at 12:49

Zn + S can be somewhat hard to ignite, use a jet lighter.

chemcam - 3-4-2013 at 15:26

I have never had problems igniting a zinc/sulfur flash powder. Are you milling to very small particle size and mixing until homogeneous? Are you certain you have zinc and not zinc oxide?

feacetech - 3-4-2013 at 17:21

I ignite mine with KMnO4 and Glycerol

Intimate mixing really helps

I used flowers of sulphur, i passed it through a 103um screen and found a number or other materials in it

Metacelsus - 3-4-2013 at 17:40

I find Zn + S needs to be lit with black powder or a blowtorch; a match or fuse just isn't hot enough. KMnO4 + Glycerol probably works, but I haven't tried it. The finer the Zn and S, the better.

violet sin - 3-4-2013 at 17:49

I tried it with some pestle ground garden sulfur and filed zinc crab pot anodes, fine as I could get them in a few min. BARELY worked at all. only got a few lill green sparks out of the 4 batches I made, each <1g. I was also wondering if my particles were just not small enough. the zinc did end up oxidized by the sulfur but the reaction was not energetic at all. had to hold flame to it for a while and it basically just fused up and became spent and brittle.

it was just a lill fun to kill some time while working abroad. I haven't gone back to the work bench and tried to really make it go with proper tools. I had really assumed it would be much more active based on some of the youtube rocket vids. live and learn

chemcam - 3-4-2013 at 18:16

Filed zinc surely is not fine enough at all. I mill the zinc for about 2 to 3 days starting from filings. My usage of the mix is for rocket propellant but I have used alone as flash powder ignited with visco fuse. The finer the particles the easier it will ignite and hotter/faster.

Trotsky - 3-4-2013 at 23:43

Sounds like your zinc is way too coarse given that it is reacting, but slowly.

KonkreteRocketry - 4-4-2013 at 00:00

The zinc is finely powdered and now its ok, but why wont magnesium and sulfur burn ? do i need a gas tourch also ?

violet sin - 4-4-2013 at 01:12

what is the preferred material for ball milling down zinc filings? I have a rock tumbler but the only thing I have is steel ball bearings in assorted sizes or lead weights.

IrC - 4-4-2013 at 02:02

Quote: Originally posted by violet sin  
what is the preferred material for ball milling down zinc filings? I have a rock tumbler but the only thing I have is steel ball bearings in assorted sizes or lead weights.


1/2" diameter, hardened Lead-Antimony (non-sparking) balls. Steel sparks. Use nothing that sparks when milling metals to dust. I cannot think of any metal in a dust state that will not burn very fast, quite possibly explosively, in air when subjected to repeated sparks. United Nuclear had them for a long time but no longer. Looking recently it seems they have nearly nothing anymore. No idea what is going on with them but below is their link so you can at least read a little about the grinding media.

http://unitednuclear.com/index.php?main_page=product_info&am...


Here is an ebay auction with a decent deal and currently available.

http://www.ebay.com/itm/200-Lead-Milling-Balls-503-Dia-For-P...