Powder Dust Explosion Review by READE

metal, inorganic Dust explosions

Reade Advanced Materials reviews:

Dust Explosions

(Publicly Available Information)

IMPORTANT NOTICE:

The following information is offered at no charge by Reade Advanced Materials for informal and general reference purposes only. Please contact the Combustible Metals Liaison at The National Fire Protection Association (NFPA) in Quincy, MA (telephone number: 1-617-770-3000) for confirmation of this information.

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Introduction:

Fire and explosion due to dust are potentially deadly risks in any process operation that employs powders or other bulk solids. Such operations are widespread throughout the chemical process industries, not only in plants that produce bulk solids, but also in units that handle raw materials, intermediates, byproducts, catalysts or additives in powder form. Death, injury, equipment damage, productivity losses and sharply increased insurance premiums are only some of the consequences of unsafe bulk solid plant operation or design.

Engineers working with bulk solids and powders must anticipate and prevent dust fires and explosions. First, they must make the proper choices during process design and plant layout, selecting and specifying the right equipment. In addition, they must be fully aware of all possible ignition sources, and some of these sources aren't too obvious.

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A) Critical Parameters For Dust Explosions

B) The Anatomy of an Explosion

C) BGIA Dust Explosion Database in Germany

Important combustion and explosion characteristics from BGIA of more than 4000 dust samples from virtually all sectors of industry

C) A Few Dust Explosion Limits:

Material	Ignition Temp. of Dust Cloud,ºC	Minimum Explosive Concentration (oz/ft³)	Relative Explosion Hazard
Aluminum	650	0.045	Severe
Al-Mg alloy		0.02	Severe
Chromium		0.23	Strong
Coal	610	0.055	Strong
Copper	900	------	Fire
Epoxy Resin	530	0.020	Severe
Iron	420	0.100	Strong
Magnesium	520	0.020	Severe
Silicon		0.11	Strong
Tin	630	0.190	Moderate
Titanium	460	0.045	Severe
Uranium	20	0.060	Severe
Zinc	600	0.480	Moderate

Note: To the best of our knowledge, the above table is based on laboratory test results by the U.S. Bureau of Mines (USBM) on dried samples of fine dusts (passing 200 mesh sieve). See USBM Investigations No. 5624, 5753, 5971, and 6516.

D) Pyrophoric Metals:

Metals generally considered to be pyrophoric in certain conditions are: aluminum, calcium, cerium, cesium, chromium, cobalt, hafnium, iridium, iron, lead, lithium, magnesium, nickel, palladium, platinum, plutonium, potassium, rubidium, sodium, tantalum, thorium, titanium, uranium, and zirconium.

Pyrophoric Definition: According to Webster's dictionary, "pyrophoric" (1) means "igniting spontaneously, as certain finely divided materials". The word "pyrophoric" has also been defined (2) as "producing sparks, when rubbed, or burning spontaneously in air, e.g. finely divided metals". Thus, a pyrophoric material is any material that ignites spontaneously or emits sparks when rubbed, scratched, or struck. Chambers' technical dictionary (3) defines pyrophoric powders as "finely divided powders which take fire or oxidize extremely rapidly when exposed to the air; usually a metal or a mixture of a metal and its oxide". By another definition, (4) a pyrophoric material is "any liquid or solid that will ignite in air below 130°F (54.4°C)." In consideration of the many fire and explosion incidents that have occurred involving the handling, transportation, and shipment of many materials in such diversified physical forms as metal machine turnings, chips, pellets, derbies, massive metal, etc., any definition of pyrophoric material should not be restricted to finely divided powders. "Pyrophoricity" (spontaneous ignition or rapid oxidation) as used in its broadest sense, therefore, must also include massive pieces of material, pure metals, alloys, carbides, hydrides, non-metallic materials, and even liquids such as the aluminum alkyls. Source: Charles R. Schmitt, P.E., C.H.C.M.

E) Useful Links:

a) MSDS Links- For pyrotechnic chemicals

b) Fire Safety In A Chemistry Laboratory

c) Hazardous Area Classifications

d) Dust Explosibility Test

F) IMPORTANT DISCLAIMERS:

ALL CHEMICAL PRODUCTS MAY BE HAZARDOUS IF IMPROPERLY USED, HANDLED OR STORED. ALWAYS ENSURE THAT YOU HAVE CONSULTED THE LATEST MATERIAL SAFETY DATA SHEET (MSDS) FOR ANY CHEMICAL PRODUCT BEFORE USING, HANDLING OR STORING A CHEMICAL PRODUCT, AND THAT YOU ARE WEARING AND USING ALL APPROPRIATE SAFETY EQUIPMENT. WE SUGGEST THAT YOU VISIT OUR MSDS RESOURCE LIBRARY IN THIS SUPERSITE.

NO WARRANTY OR GUARANTEE, EXPRESSED OR IMPLIED, IS MADE REGARDING PERFORMANCE, STABILITY OR OTHERWISE. THIS FREE LINK INFORMATION IS NOT INTENDED TO BE ALL-INCLUSIVE AS THE MANNER AND CONDITIONS OF USE, HANDLING, STORAGE AND OTHER FACTORS MAY INVOLVE OTHER OR ADDITIONAL SAFETY OR PERFORMANCE CONSIDERATIONS. WE BELIEVE THAT THE NATIONAL FIRE PROTECTION ASSOCIATION (NFPA) IN MASSACHUSETTS WILL BE ABLE TO RESPOND TO QUESTIONS REGARDING SAFE HANDLING AND USE PROCEDURES. SAFE HANDLING AND USE ULTIMATELY REMAINS THE RESPONSIBILITY OF THE END-USER. NO SUGGESTIONS FOR USE ARE INTENDED AS, AND NOTHING HEREIN SHALL BE CONSTRUED AS, A RECOMMENDATION TO INFRINGE ANY EXISTING PATENTS OR TO VIOLATE ANY FEDERAL, STATE OR LOCAL LAWS.

Telephone Contact Numbers:
East Coast USA: +1-401-433-7000 / West Coast USA: +1-775-352-1000 / Latin América: +507-314-1282

This page was last updated on 4 October 2005

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technical test dust thermal spray thick three thin time toll tpn tube turnings tzm ultrathin un under uncalcined undistilled vacuum visa water wire whisker wool yarn yellow / / compound key words: acrylic aluminate arsenide babbitt boride bromide carbide carbonate cermet chloride clad codep cubane cupric cuprous deoxidizer ferric ferrous fluoride fused hydride hydroxide iodide imide manganin mes metallizing nitrate nitride organometallic oxide oxychloride phosphate phosphide salt selenide silicide sulfide sulfate 3d 3-d telluride titanate tungstate vanadate zirconate // elements key words: actinium alumina americium aluminum nitride aluminum oxide aluminum powder antimony powder barium beryllium bismuth powder boron nitride boron carbide calcium chromium powder copper powder germanium glass powder gold powder hafnium powder indium powder iron powder carbonyl iron powder iron oxide lanthanum lithium magnesium powder magnesium oxide manganese powder manganese di oxide molybdenum powder mullite neodymium powder nickel powder nickel oxide palladium powder phosphorus platinum powder potassium rhenium rhodium rubidium ruthenium powder samarium scandium selenium powder silicon powder silicon carbide silicon dioxide silica silicon nitride silver powder silver oxide sodium strontium sulfur tantalum powder tellurium, terbium, thallium, tin powder tin oxide titanium powder titanium carbide titanium diboride titanium dioxide titania titanium nitride titanium oxide tungsten powder tungsten oxide vanadium powder, vanadium oxide, yttrium powder, yttrium oxide, yttria zinc powder zinc dust zinc oxide zirconium powder zirconium oxide zirconia / / mineral key words: anatase baddeleyite barite basalt bauxite bentonite boehmite boric acid boric oxide borax celestite chromite clay colemanite cordierite corundum cristobalite cryolite cuprite diamond diatomaceous earth diatomite diopside dolomite emery enstatite feldspar flint fluorite fluorspar fullers earth galena garnet goethite granite graphite gypsum hematite ilmenite kaolin kyanite lime limestone magnesite magnetite manganite mica micaceous iron oxide mio molybdenite monazite montmorillonite muscovite nickel-iron olivine sand flour perlite petalite pumice pyrite iron pyrite quartz quartzite rock wool rutile sand scheelite sillmanite smectite soapstone spinel spodumene stibnite sulfide sulfate sulfur talc trap rock triploi vermiculite wheat chaff wheat starch wollastonite zeolite zircon sand fluor zirconium silicate / / general key words: aas abrasive acid activated additive aerosol agglomerates air alloy alpha aluminide american amorphous ampoule angstrom argon atomization bar basis bead beta black blending blocks black brazing briquette brown bubble buckyball buckytube calcined can card ceramic chip chop circular clad classification coating cold colloidal commerce commercial composite compound conductive credit crushed cryogenic crystal crystalline cubes custom cylinder dendritic dense density deposition diameter dielectric dimensional disc discontinuous discover disposable distilled doped drop drum dry dust e-commerce electronic electrolytic elemental enriched evaporation express felt fiber filings fine filler flake foam foil food grade frit fullerene fused gamma gas gauze glass grade grain granule granular grignard grinding grit ground heat hexane helium homogenizing hot inch in inert ingot inorganic intermetallic irregular jar j-i-t just leaf liquid lump kanban magnetic massive master media memory mesh metal metallic melted metallic micro micron microcrystalline milling millimeter mineral mm molecule mro nanocrystal nanomaterial nanometer nanophase nanostructure nanotube nanowire natural needle nitrogen nrc oil optical organic packaging particle paste pellets pharmaceutical grade phase pieces planar plasma spray plastic plate platelet polishing polycrystalline polymer porous powder ppm precipitated precious precursor premium pressed pressure printing processing procurement pulverize puratronic pvd pzt quasicrystal radioactive random rapid rare earth reacted reaction reagent rectangular red redistilled reduction refined reinforcement remelted ring rod round screening secure service set shape sheet shot sieve sifting single sink size slug soft solder solid solidification soot sphere spherical spheroidal splinter sponge sputtering sintered sol gel stabilized standard sub sublimed superabrasive super superalloy superconductor synthesis synthetic tablets tabular target tear technical test dust thermal spray thick three thin time toll tpn tube turnings tzm ultrathin un under uncalcined undistilled vacuum visa water wire whisker wool yarn yellow / / compound key words: acrylic aluminate arsenide babbitt boride bromide carbide carbonate cermet chloride clad codep cubane cupric cuprous deoxidizer ferric ferrous fluoride fused hydride hydroxide iodide imide manganin mes metallizing nitrate nitride organometallic oxide oxychloride phosphate phosphide salt selenide silicide sulfide sulfate 3d 3-d telluride titanate tungstate vanadate zirconate // elements key words: actinium alumina americium aluminum nitride aluminum oxide aluminum powder antimony powder barium beryllium bismuth powder boron nitride boron carbide calcium chromium powder copper powder germanium glass powder gold powder hafnium powder indium powder iron powder carbonyl iron powder iron oxide lanthanum lithium magnesium powder magnesium oxide manganese powder manganese di oxide molybdenum powder mullite neodymium powder nickel powder nickel oxide palladium powder phosphorus platinum powder potassium rhenium rhodium rubidium ruthenium powder samarium scandium selenium powder silicon powder silicon carbide silicon dioxide silica silicon nitride silver powder silver oxide sodium strontium sulfur tantalum powder tellurium, terbium, thallium, tin powder tin oxide titanium powder titanium carbide titanium diboride titanium dioxide titania titanium nitride titanium oxide tungsten powder tungsten oxide vanadium powder, vanadium oxide, yttrium powder, yttrium oxide, yttria zinc powder zinc dust zinc oxide zirconium powder zirconium oxide zirconia / / mineral key words: anatase baddeleyite barite basalt bauxite bentonite boehmite boric acid boric oxide borax celestite chromite clay colemanite cordierite corundum cristobalite cryolite cuprite diamond diatomaceous earth diatomite diopside dolomite emery enstatite feldspar flint fluorite fluorspar fullers earth galena garnet goethite granite graphite gypsum hematite ilmenite kaolin kyanite lime limestone magnesite magnetite manganite mica micaceous iron oxide mio molybdenite monazite montmorillonite muscovite nickel-iron olivine sand flour perlite petalite pumice pyrite iron pyrite quartz quartzite rock wool rutile sand scheelite sillmanite smectite soapstone spinel spodumene stibnite sulfide sulfate sulfur talc trap rock triploi vermiculite wheat chaff wheat starch wollastonite zeolite zircon sand fluor zirconium silicate /