Determined in this way, 5 gram samples of the following salts gave the
results indicated below:--
"Barium Chloride"
Salt. Required. Sulphuric Oxide.
Copper sulphate 64.25 c.c. 32.12 %
Magnesium sulphate 65.25 " 32.62 "
Zinc sulphate 56.25 " 28.12 "
Ferrous sulphate 58.25 " 29.12 "
Sodium sulphate 51.25 " 25.60 "
~Determination of Sulphuric Oxide in Barytes~ (Heavy spar).--Fuse 2
grams of the powdered mineral with 5 grams of "fusion mixture" for five
minutes; and, when cold, extract with water. Filter, acidulate the
filtrate with an excess of 10 c.c. of acetic acid, dilute, boil, and
titrate. For example, a transparent crystallised sample required 27.0
c.c. of barium chloride, which is equivalent to 13.6 per cent. of
sulphur, or 34.0 per cent. of sulphuric oxide. Theory requires 34.3 per
cent. of the latter. Since both carbonate of soda and potash are liable
to contain sulphates, a blank determination should be made on 5 grams of
the "fusion mixture," and the amount found be deducted from that got in
the assay.
PRACTICAL EXERCISES.
1. The price of sulphur in an ore being 4-1/2d. per unit in the
northern markets, what would be the price of a ton of ore containing 49
per cent.
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