1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Why are Grain Dust explosive?

  1. Sep 23, 2009 #1
    I realise that this topic is more towards chemistry however i was wondering why grain dust particles are explosive. Is there any carbon atoms in the dust particles that fuel these explosions?
     
  2. jcsd
  3. Sep 23, 2009 #2

    A.T.

    User Avatar
    Science Advisor
    Gold Member

    Are you asking if organic molecules contain carbon atoms? Yes, they do:
    http://en.wikipedia.org/wiki/Organic_compound
     
  4. Sep 23, 2009 #3

    Borek

    User Avatar

    Staff: Mentor

    It is mostly kinetics of combustion - there is a huge surface on which combustion can take place, so it happens very fast. Same story with coal dust.

    --
    methods
     
  5. Sep 23, 2009 #4
    Same with almost any dust. I've read (although with no source attached) that you could make asbestos dust explode if it were fine enough. Certainly this is the case for fine metalic dusts
     
  6. Sep 23, 2009 #5

    Borek

    User Avatar

    Staff: Mentor

    Not any dust - it has to be able to react with oxygen giving off heat. Otherwise it won't work (which makes me strongly doubt asbestos idea).

    --
    methods
     
  7. Sep 23, 2009 #6
    Sounds right. The article was pointing out that even elements or compounds which only react very reluctantly with oxygen (which leaves me with visions of teenager type elements sitting in a corner refusing to react) will do so explosively when in dust form.

    A quick wiki search shows that there are at least 3 different types of asbestos - all chemically very different. My A-Level chemistry didn't prepare me well enough to deal with reactions of
    Na2Fe2+3Fe3+2Si8O22(OH)2
    (Blue Asbestos)!!
     
  8. Sep 23, 2009 #7
    do these dust particles require an igniter or can they simply combust through their own kinetic energy through friction?
     
  9. Sep 24, 2009 #8

    Borek

    User Avatar

    Staff: Mentor

    Never heard about them exploding without ignition.

    --
    methods
     
  10. Sep 24, 2009 #9

    Borek

    User Avatar

    Staff: Mentor

    Well, Fe(II) can be oxidised to Fe(III), so perhaps there is a slight chance of reaction taking place. Which shifts my doubts from 'strong doubts' to 'just doubts' :wink:

    --
     
  11. Sep 24, 2009 #10

    alxm

    User Avatar
    Science Advisor

    Statistically very unlikely. Or simply: I don't think so.

    What'd be more likely is the dust and friction causing a discharge of static electricity which could act as an ignition source.
     
  12. Sep 24, 2009 #11
    ^^ yea that makes more sense. thankyou
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Why are Grain Dust explosive?
  1. Coarse graining (Replies: 1)

  2. Coarse Graining (Replies: 2)

  3. Entropy and Dust (Replies: 8)

Loading...