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Vanadium in rust?

  1. May 5, 2009 #1

    PDC

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    would one expect to find vanadium in the 'surface rust' collected from an underground gasoline storage tank (from gas station). (tank used prior to 1990's when new regulations required corrosion resistance on tanks)

    Further, if there was vanadium then what percent of the rust 'could it' constitute and finally if the rust was placed in the soil would the vanadium bind with the soil particles (ie iron in soil) Soil is volcanic.



    Thanks,
    PDC
     
  2. jcsd
  3. May 5, 2009 #2

    Astronuc

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    Was the vanadium on the inner surface or outer surface? I'm guessing inner, but if there was a crack, it could be outer surface. I expect the vanadium is an impurity in the gasoline, and it accumulates over time.
     
  4. May 6, 2009 #3

    PDC

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    based on 2nd hand info I'm told that soil from around a 50's to 80's storage tank with some evidence of surface rust would also contain vanadium as a part of the steel used to make the tank and therefore the soil removed from around the rusty (just surface rust) tank would / shouldscontain vanadium.

    Essentially I'm trying to determine if this makes sence and also what possible proportion of vanadium might exist in the rust / soil which 'might' contain rust.

    Thanks,
    PDC
     
  5. May 6, 2009 #4

    Astronuc

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    Would one happen to know the type of steel used?

    Without knowing the composition, it would be difficult to assess the vanadium content.
     
  6. May 6, 2009 #5

    PDC

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    I am trying to research the type of steel in used for the tank however it was installed in the 50's and removed in the 90's ( I believe due to regulations requiring underground at that time tanks be upgraded to have corrosion resistance etc) but in any case the steel would be a normal type of steel plate used for such purposes and not the type of steel used for tools etc. which would have a higher cr and v content.

    The rust noticed was 'surface' rust not rusted through holes etc so the question would relate to surface rust that would have contacted the soil and presumably flaked off and got mixed in with the soil which was removed in the process of removing the tank.

    Due to a small leak detected around a 'connection' to the tank all of the soil that surrounded the tank was removed and placed on a remediation bed. So essentially the point is could that soil from the remediation bed have a higher than normal content of vanadium and if so how could this be established or could it be?

    Thanks,
    PDC
     
  7. May 6, 2009 #6

    Astronuc

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    You might try contacting the Steel Tank Institute ( https://www.steeltank.com/ ), a trade group which represents manufacturers and suppliers of steel tanks, and see if they can provide information on compositions of typical steels used in underground storage tanks (USTs) for gasoline/fuel.

    Unless one determine the materials specification, e.g. ASTM A36, it may be difficult to determine the composition. It could very well be the vanadium has accumulated from the fuel. If the vanadium is on the outer surface, it might be there after years of leaking.

    One would need to take the soil away from the tank and send it to a lab for chemical analysis.
     
  8. May 7, 2009 #7

    PDC

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    Thanks again!

    I've contacted the steel tank institute but as yet have had no reply re the steel type but it is likely the ASTM 36 you cite with a V content range of .15 to .25%. Assuming that, would it be possible to determine the concentration of V in the rust. note * the tank was only used for gasoline and unleaded not diesel or fuel oils which might contain Vanadium. The potential Vanadium source is only being attributed to the surface rust on the tank not the gasoline.

    The suggestion is that if the soil surrounding the tank (dug out in 1995) contained Vanadium from the surface rust and this soil was then added to, laid on or mixed with other soils from the area then this would raise the Vanadium content of soils with which the 'tank' soil was added to.

    If this is true and the tank metal contained .20% Vanadium then would the tank surface rust also contain the same proportion of Vanadium and would that noticably raise the Vanadium levels in the soil surrounding and making contact with the rust.

    Or is .20% such a small amount so as to be insignificant or unmeasureable.

    And finally what route could be followed to determine if this 'remediated' soil from around the tank was mixed with other soils from the same general area?

    Thanks,

    PDC
     
  9. May 8, 2009 #8

    PDC

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    the 'steel tank institute' says it is likely astm 36 however they do not have specific info for older tanks.

    PDC
     
  10. May 8, 2009 #9

    Astronuc

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    I'm not surprised. If it's 1950's, there's probably no way to tell what impurities there is in the steel, and it may not be A36, at least not current specs.

    A level of 0.15 to 0.25% is high for V, which would normally be an order of magnitude lower for a steel like A36, if that.

    I wonder if V was added through scrap recycling.

    If there was V in the steel, the rust should probably have about the same proportion of V to Fe.
     
  11. May 8, 2009 #10

    PDC

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    the Steel Tank Institute came back with 3 possibilities;

    A -635 with a V content of .08 to .18
    A - 569 with no V content
    ASTN A36 with no specified V content

    I will continue to try and research the tank manufacturer if records are available.

    My question n ow would be;

    if it is A 569 or ASTM A 36 would this mean there is no measureable V content and is it possible there really is no V content in the old tank.

    and

    if it is A - 635 with the .08 to .18 % range would that mean that likely .o8 to .18 % of the rust (for example measured by weight) would be the vanadium content of the rust. ie
    100 lbs rust would contain .08 to .18 lbs vanadium

    Thanks again for your help!

    PDC
     
  12. May 8, 2009 #11

    Astronuc

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    Correct - if the steel was made to spec.

    and

    Pretty much. I wouldn't expect the vanadium to migrate/leach from the rust layer.

    As far as I know, vanadium in soil would be limited to a few regions in states like Colorado, New Mexico, and perhaps some other states in the Rocky Mountains.
     
  13. May 24, 2009 #12
    i did not know why the concern but found this
    so the limits here should be of concern

    ''''All vanadium compounds should be considered to be toxic. Tetravalent VOSO4 has been reported to be over 5 times more toxic than trivalent V2O3.[53] The Occupational Safety and Health Administration (OSHA) has set an exposure limit of 0.05 mg/m3 for vanadium pentoxide dust and 0.1 mg/m3 for vanadium pentoxide fumes in workplace air for an 8-hour workday, 40-hour work week.[54] The National Institute for Occupational Safety and Health (NIOSH) has recommended that 35 mg/m3 of vanadium be considered immediately dangerous to life and health.''''
     
  14. May 25, 2009 #13

    Gokul43201

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    Not exactly. Rust that contained 100lbs of Fe in it would still contain 0.08 to 0.18lbs of V in it (assuming no leaching or migration of any kind). But it typically takes about 140 - 200lbs of rust to get 100lbs of Fe (the number depends on how much moisture there is in the rust; if you heat the rust to remove all the moisture, the number will be pretty close to the 140lb end).

    So, the V fraction of the rust will be somewhat smaller than the V fraction in the parent steel, assuming no transport and assuming the surface of the steel had the same composition as the bulk (not necessarily true: V and Cr like to segregate at grain boundaries and surfaces).

    There's too many unknowns to get any meaningful numbers, if you ask me, but with all these assumptions in place, a steel with V < 0.18% will produce a rust with V < 0.13% (of the weight of the rust).
     
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