3053 "
Deduct silver in red lead 0.0017 "
------
Silver in ore 0.3036 " = 495.9 ozs. per ton.
_By Scorification._--Ore taken, 3 grams.
Silver got. 0.0425 gram
Silver from slag 0.0022 "
Silver lost in cupellation 0.0020 "
------
0.0467 "
Deduct silver in lead 0.0015 "
------
Silver in ore 0.0452 " = 492.2 ozs. per ton.
~Determination of Silver in Silver Precipitate.~--This substance
contains, in addition to metallic silver and gold, sulphates of lead and
lime; oxides of zinc, copper, and iron; and more or less organic matter.
The sample as received is generally free from "water at 100° C."; and,
since it rapidly absorbs water, care should be taken in weighing it.
Since it contains combined water it is not suited for scorifying;
therefore the determination of silver and gold (fine metal) is made by
pot assay. Weigh up 5 grams of the precipitate, mix with 100 grams of
litharge and 1 gram of charcoal. Melt in a crucible at a moderate heat
and pour. Detach the slag, replace in the crucible, and, when fused, add
a mixture of 20 grams of litharge and 1 gram of charcoal. When the
fusion is again tranquil, pour; and cupel the two buttons of lead.
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