[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


Richard Illig (717) 327-3568 wrote:
>     RIC
>     ---------------------------------------------------------------
> Subject: Calcium Fluoride Sludge Use
> Date: Fri, 7 Feb 1997 06:41:00 EST
> From: "Richard Illig (717) 327-3568" <ILLIG.RICHARD@a1.pader.gov>
> To: Remote Addressee <p2tech@great-lakes.net>
>     FROM: R. Illig
>     RE: Calcium Fluoride Sludge  and
>         Hydrofluoric Acid for Etching Glass
>     E-MAIL: illig.richard@a1.dep.state.pa.us
>     One and All,
>     1)  I too would be very interested in alternate uses, or users,
>     for calcium fluoride sludge...pending full analysis of the sludge
>     of course.  I have a site visit coming up next week and that is
>     one of the waste streams needing addressed.
>     I request that anyone answering the earlier request for
>     information on CaF copy me and/or post the response to the list.
>     2)  About a month ago, I requested information on any known
>     methods for etching glass that would avoid the use of hydrofluoric
>     acid (a better means for eliminating generation of the calcium
>     fluoride sludge).  Unfortunately, the best, and only, response I
>     received was not applicable, and involved the use of abrasive
>     material.  I'm rather sure a chemical etching process would be
>     needed (the inside of a glass (light) bulb is the object needing
>     etched).
>     Assumming I'm stuck with the hydrofluoric acid for etching, my
>     next thought was to study the waste treatment system.  A
>     significant drop in the molecular weight of the sludge MAY be
>     possible by looking for replacements for the calcium source.
>     Sodium, potassium, or other lighter elements that have similar
>     chemical properties may allow for substitution of the calcium
>     material.  Am I dreaming (about dead chickens) or does this seem
>     like a worthy P2 method for attacking the problem?
>     Any takers??
>     As usual, thank you for any consideration.
>     Ric

Calcium fluoride (CaF2) MAY be able to be recycled back to the HF
production process.  HF is made from fluorspar, which is CaF2.  However,
the potential for recycling is dependent on water content and, of
course, economics.

I am not aware of anyone doing this now, but I have heard of
facililities considering it as part of a project that regenerates KOH
from neutralized fluoride-containing waste water.

Contact your HF acid source or Chemtech, Allied, or Dupont to discuss
the feasibility.  

Also, please let us know if you succeed!

				Bill Simon

*  William (Bill) C. Simon                     wcsimon@jol.mobil.com  *
*  Environmental Advisor                                              *
*  Mobil Oil Corporation                                              *
*  P.O. Box 874                               Phone: +1.815.423.7749  *
*  Joliet, Illinois  60434                      Fax: +1.815.423.7726  *