IMPROVEMENTS IN THE MANUFAC- TURE OF ANHYDROUS SULPHURIC ACID, OIL OF VITRIOL, AND HYDROUS SULPHURIC ACID, WHICH IMPROVEMENTS RELATE ALSO TO THE CONCENTRATION OF SULPHURIC ACID CONTAINING WATER
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Frank Wirth at the Office of the
Commissioners of Patents on the 16th April 1878. A cominunication from
Conrad Lange and Carl Göpner, of Opladen; in the Empire of Germany.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at Frank-
fort-on-the-Main, in the Empire of Germany. "IMPROVEMENTS IN THE MANUFAC-
TURE OF ANHYDROUS SULPHURIC ACID, OIL OF VITRIOL, AND HYDROUS SULPHURIC
ACID, WHICH IMPROVEMENTS RELATE ALSO TO THE CONCENTRATION OF SULPHURIC
ACID CONTAINING WATER." [A communication from Conrad Lange and Carl
Göpner, of Opladen, in the Empire of Germany.]
In the manufacture of sulphuric acid as heretofore practised, the obtaining of
the anhydrite as an immediate result of the roasting process has not been attempted,
because the quantity of anhydrite obtained by means of arrangements hitherto
employed has been too small for making use thereof.
The method to which this Invention relates has for its object to increase the
quantity of anhydrite resulting from the roasting process, and to produce the same
as a continuation of the roasting process. For this purpose the gases obtained by
the usual roasting process in the manufacture of sulphuric acid are conducted through
enamelled tubes of graphite, cast iron, or other suitable conduits which are highly
heated, and the diameter of which is in proportion to the quantity of the gases con-
ducted through them.
For effecting the combination of the low products of oxidation of the sulphur
with oxygen these conduits are filled with waste pyrites, peroxyde of iron,
platinized asbestos, or other matters having a similar effect. The mixture of gas
leaving the conduits is cooled and the condensed product directly collected for
obtaining the anhydrite.
In combination with the manufacture of alizarine the gases containing anhydrite
are brought in contact with anthraquinone long enough and at a sufficiently high
temperature to obtain the desired sulpho-acids of anthraquinone, which in the well-
known manner are transformed into alizarine and purpurine. This process relates
also to all other sulpho-acids, as, for instance, the sulpho-acid of benzole.
For the manufacture of oil of vitriol the uncondensed gases or the cooled gases

page_text: leaving the conduits are conducted into a tower, which like the well-known
"Glover" or "Gaylussac" towers is filled with coke or other matters offering a
large surface, and in which the concentrated sulphuric acid meets these gases
flowing in an opposite direction. The quantity of anhydrite in the acid leaving
the tower may be increased by distilling off a part of the acid obtained, and by
collecting the same in a receptacle filled with oil of vitriol. The same may also be
increased by conducting the acids several times through the tower.
For concentrating diluted acids these acids are brought into contact with the
gases containing anhydrite enclosed in the tower; they are allowed to remain in
contact until the desired degree of concentration has been attained. By my said
improved method the costly method of concentrating sulphuric acid by evaporation
in vessels of lead or platina may be dispensed with. The gases finally escaping
from the tower can be used again, or several times, and if desired, may be mixed
again with air in the same apparatus, or in others, and treated in the same manner
as the direct roasting gases; or they may in the usual manner he converted into
sulphuric acid. It is recommended to previously dry the air to be introduced.
If in the tubes oil of vitriol or hydrous sulphuric acid should be produced,
moistened air, or air and steam in suitable proportions to the anhydrite, is intro-
duced.