Argelac

Caroline Fry <cfry [at] vicnet__net__au>

>The curator found samples of "Argelac", in fabric bags inside the
>travelling crates.  The origin of the material appears to be
>Germany, as all the information on the bags is in German. The
>curator believes that "Argelac" is a moisture/ humidity absorbing
>material.

For sure, Argelac is some natural zeolite: they are minerals
extensively used in many industrial processes.  The sedimentary
zeolites (clinocliptolite, mordenite, chabasite, phillipsite,
erionite) are rocks of volcanic origin very common in Italy, USA,
Japan. I do not know about Australia. They are aluminosilicates
characterised by the property of adsorbing water and humidity  (up
to 30% in volume) their cost is very very low, less 0.5 USD per kg.
Once saturated they can be easily regenerated in ventilated oven at
250 deg C for 12 hours;  then must be stored in a sealed metallic
container full filled. There exist also synthetic zeolites (produced
by UOP and Union Carbide) that are more efficient than naturals but
the process of water adsorption in this case is exothermic.

Ercole Gialdi
R.G.I. Resource Group Integrator s.r.l.
V.le Nazario Sauro no 8
16145 Genova, Italy


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                  Conservation DistList Instance 13:58
                   Distributed: Friday, May 19, 2000
                       Message Id: cdl-13-58-007
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