Barium carbonate plating

The radioactivity determinations were made on infinitely thick barium carbonate plates (6), corrected for coincidence and background using a Tracerlab TGC-2, G.M. tube, and a Nuclear Instrument and Chemical Corporation Scaling Unit Model 162. The individual counting rates were known to within an accuracy of 3%. 

Ammonium Carbonate,(Nil 4)2C03 mw 96.09, col cryst plates si toxic (Ref 12,p 275). See also Spec MIL-A- 13938. DeMent (Ref 14) used this compd in smoke producing compns and Stevenson (Ref 11) used it to vaporize diphenylchloroarsine other smokes Barium Carbonate, BaC03 mw 197.37, wh powd, mp 1740 at 90atm, bp dec, d 4.43 this compd is poisonous when ingested (Ref 12,pp 331-2). It is used in expl mixts in pyrotechnics. (See also Spec JAN- B- 624)... 

You simply go down to your local chemist s supply store and buy some copper oxide, some barium carbonate, and some yttrium oxide, all readily available in white powders. You go home and you do a little calculation so you ll get the ratios right, so that the yttrium, barium, and copper are in a ratio of 1-2-3. If you ve had any chemistry at all, that s very easy to do. Then you simply stir the mixture thoroughly in a pan and stick it in your microwave oven and you bake it at 950° F for about four hours—and when you pull it out, you ve got this black powder. You compress it into a little plate, and you put it back in the oven to sinter it and make it one solid piece. And if you know a little more about what you re doing, you blow some oxygen on it and... 

The earliest method for BaS is described by Stenhouse who dissolved trinitroresorcine in 100 parts of boiling water and added excess of barium carbonate [28]. On cooling he obtained pale yellow rhomboidal plates. Analysis showed presence of three waters of crystallization. 

Paste Mixing. The active materials for both positive and negative plates are made from the identical base materials. Lead oxide, fibers, water, and a dilute solution of sulfuric acid are combined in an agitated batch mixer or reactor to form a pastelike mixture of lead sulfates, the normal, tribasic, and tetrabasic sulfates, plus PbO, water, and free lead. The positive and negative pastes differ only in additives to the base mixture. Organic expanders, barium sulfate [7727-43-7] BaSO carbon, and occasionally mineral oil are added to the negative paste. Red lead [1314-41 -6] or minium, Pb O, is sometimes added to the positive mix. The paste for both electrodes is characterized by cube weight or density, penetration, and raw plate density. 

Crucibles fitted with permanent porous plates are cleaned by shaking out as much of the solid as possible, and then dissolving out the remainder of the solid with a suitable solvent. A hot 0.1 M solution of the tetrasodium salt of the ethylenediaminetetra-acetic acid is an excellent solvent for many of the precipitates [except metallic sulphides and hexacyanoferrates(III)] encountered in analysis. These include barium sulphate, calcium oxalate, calcium phosphate, calcium oxide, lead carbonate, lead iodate, lead oxalate, and ammonium magnesium phosphate. The crucible may either be completely immersed in the hot reagent or the latter may be drawn by suction through the crucible. 

The barium salt is easier to obtain in solid form than is the corresponding potassium salt. Dissolve 15 g. of crystallized barium hydroxide in 50 cc. of warm water and divide the solution into two equal parts. Completely saturate the one portion (in a stoppered flask) with hydrogen sulfide and then add the other portion, thus forming a solution of barium sulfide. Add about 1 cc. of carbon disulfide and shake from time to time. It is better to add the carbon disulfide by conducting a current of coal gas (from the laboratory gas supply) through a little carbon disulfide in a wash flask and thence into the solution of barium sulfide. The barium salt precipitates as a yellow crystalline powder. The filtered precipitate should be washed first with water, then with half alcohol, finally with pure alcohol and dried on a hot plate. A second crop of crystals may be obtained by allowing the wash alcohol to drain into the mother liquor. 

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