What you refer to is metallic zinc powder. The salts are different. Iron
powder will do a similar thing but ferric oxalate, an iron salt is different.
I have made double salts of palladium with the chlorides of magnesium,
barium, ammonium, potassium, lithium, zinc, and a few that I can't
remember. The magnesium double salt is interesting and seems to act
somehwat similar to the lithium double salt and it might give colder toned
image with developing out than the ammonium salts. The barium salt makes a
precipitate and doesn't work too good, well actually not at all. The cesium
palladium salt is interesting as cesium chloride is the heaviest common
alkalai metal salt and it is used in the Ziatype system as a companion to
the the lithium palladium salt - lithium chloride being the lightest
alkalai metal salt. I've never made a palladium double salt with strontium
which might make interesting prints and bismuth hasn't been tried. Titanium
chlorides are really nasty things, and arsenic trichloride is a known
carcinogen.
Sorry, I just added my ruminations on the double salts of palladium for
anybody in an experimental frame of mind. It seems hard to predict what
these things will do in practice. I am not a trained chemist and actually
have never taken either a high school or college chemistry course and am
always surprised when I asked a formal trained chemist what will the
attributes be of a certain compound and the answer I get is "try it and see."
I thought that lithium chloroplatinite might be a highly soluble and
hygroscopic compound much the same as lithium chloropalladite. Nope, it
turns out to be an insoluble precipitate. Well least least as far as my
experiments have gone, though I have to admit that this is not totally
conclusive yet.
Dick
At 12:15 AM 5/1/97 -0400, you wrote:
>Richard Sullivan wrote:
>>
>...
>> I've seen references to using zinc acetate instead of mercuric chloride in
>> historical literature on pt/pd processes. I've dabbled with it with no
>> success. ...
>> I've made what appears to be a double salt of palladium and zinc, but it
>> doesn't make good prints, just a grainy mess.
>>
>
>Dick,
>
>I have been told that to reclaim Pt and Pd from spent clearing bath,
>zinc is added. The zinc replaces the Pt or Pd causing them to
>precipitate out. (Note: this doesn't help environmentally, but it does
>recover the more expensive metals.)
>
>Could this be what is going on to produce the grainy mess?
>
>Jeff
>
>
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