Tim and others,
Reacting BrF5 with KBr (thought it needed to be at 100 to 200 degrees or so
to react better?), you form KF (solid; white) and Br-gas. The Br-gas is
heavy and reddish-orange in colour and toxic. Be also careful with KF, it is
hygroscopic and will form HF by reacting with moisture from air.
Potassium bicarbonate will do a similar trick at room temperature as KBr.
If indeed your cylinders are emty (check pressure) and only traces of BrF5
or ClF3 are present you can open them inside a fluorine resistive fumehood,
of course after having taken all correct percautions, such as waring proper
gloves and safety mask for the face. If you want to be very safe you better
freeze the bottompart of the cylinders with liq-N2 before opening, and then
let them come back to room temperature slowly (you will see fumes start
coming out; can be white, orange or yellow) while neutralizing eventual
rests of the reactants by slowly and carefully pooring into a ceramic
container with your neutralizing agent. This can be done without having your
hands inside the fume hood by using common lab equipment: the cylinder is
fastened to a stand and can turn, operated by a stick from outside the
fumehood (with the fumehood door as far closed as possible), and thus
pooring the BrF5, or whatever product in the cylinder, into the neutralizing
agent. Do this very slowly and in very small portions, otherwise you risk
large amounts of gases circulating in the fume hood or violent reactions
with eventual spattering! Only do this if relatively small portions of BrF5
or ClF3 are left in the cylinder (as you stated is the case for you)!
After completely emptying the cylinders, leave them in the back corner of
the fume hood for a longer time (evtl. couple of months), of course with the
fumehood door closed. After this procedure no risk exists for the containers
and in principle they simply can be disposed in a normal way, without
classification of hazardous or toxic waste. Be aware there still may be
solid fluorides inside the cylinders because of corrosion, changing the
story a bit - then common procedures for fluorides are valid... I am certain
still far less expensive then the procedure as you described.
Just a cheaper suggestion....
Best wishes,
Pier.
****************************************************************
Delta Isotopes Consultancy
Dr. Pier A. de Groot
Pastoor Moorkensstraat 16
2400 Mol - Achterbos
Belgium
Tel. +32 (0)14 326 205
e-mail: [log in to unmask] or [log in to unmask]
Visit my WEB-site about my ³Handbook of Stable Isotope Analytical
Techniques², including pdf files of an order form and a flyer for
downloading, at:
http://users.pandora.be/handbook/index.html
last update: October 1, 2004
Volume I is now available. Volume II is expected to be available medio 2005.
****************************************************************
> Greetings all...
>
> We have six empty cylinders in storage in our building that our Waste
> Management department is trying to dispose of. Five of them are
> bromine pentafluoride and one is chlorine trifluoride. So far the only
> company that Waste Management can find to dispose of these cylinders
> wants $2500 each to do so!! As the cylinders are old (over 10 years or
> so) Ozark Mahoning (the manufacturer) does not want them back.
>
> Can anyone tell me how they dispose of these nasties?
>
> Another question: how are people disposing of any unreacted BrF5 and
> ClF3 after silicate analysis? We invert our u-trap containing frozen
> unreacted BrF5 over a bucket of KBr in a fumehood, but I've never
> understood the reaction of these two compounds. What neutralizing
> chemical are others using, and what are the products of the chemical
> reaction?
>
> Thanks...
>
> Tim Prokopiuk
>
> -----------------------------------------------
> Tim Prokopiuk
> B. Sc. Geology/Technician
> Saskatchewan Isotope Laboratory
> Room 241
> Department of Geological Sciences
> University of Saskatchewan
> 114 Science Place
> Saskatoon, Saskatchewan, Canada
> S7N 5E2
> Phone: (306) 966-5712
> Fax: (306) 966-8593
> Email: [log in to unmask]
>
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