Tom Buck on wed 14 aug 02
Yes, David:
the ZnO does disappear when moderate to heavy reduction is carried
out ... you & I have been over this before.
BUT ZnO is a strong flux that kicks in early and brings about a
melt earlier on than would occur if it were absent. So, some ZnO can help
some glazes by making the liquidus (molten glass) appear at a lowercone
and therefore allow some time for the slow gas/liquid reactions to occur.
eg, CuO goes to Cu2O and Cu (metal). The CuO is dissolved in the liquidus
and the H2/CO have to impinge of the liquidus surface and cause the copper
red to appear. In step the ZnO goes to Zn (metal) and goes up the flue;
but its work has already been done.
later. Peace. Tom B.
Tom Buck ) -- primary address.
"alias" or secondary address.
tel: 905-389-2339 (westend Lake Ontario, province of Ontario, Canada).
mailing address: 373 East 43rd Street, Hamilton ON L8T 3E1 Canada
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