IMPROVEMENTS IN THE MANUFACTURE OF SULPHATE OF AMMONIA, AND IN PREVENTING NUISANCES ARISING FROM SAID MANUFACTURE
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Peter Spence and Thomas Illingworth
at the Office of the Commissioners of Patents on the 16th July 1878.
PETER SPENCE, of Manchester, in the County of Lancaster, Manufacturing
Chemist, and THOMAS ILLINGWORTH, of Leeds, in the County of York, Manufac-
turing Chemist. "IMPROVEMENTS IN THE MANUFACTURE OF SULPHATE OF AMMONIA,
AND IN PREVENTING NUISANCES ARISING FROM SAID MANUFACTURE."
In carrying out our Invention we take the ammoniacal water or liquor of the gas
works and pump it through coils of pipe or other such aapparatus, whereby it may
be heated by vapours arising from a part of the process, which will hereafter be
described. From thence it is carried to the top of a tower, say six feet in diameter
and thirty feet high, filled with bricks, tiles, or other such materials, so as to leave
numerous interstices. The liquor runs down over the surfaces of the said materials,
and runs out at the lower part into a boiler, and after running therein (say four
hours) it passes into a second boiler. The first boiler is now supplied with a charge
of milk of lime sufficient to set free the fixed ammonia, and steam (say of 50 lbs.
pressure) is blown into it, so as to boil and agitate it strongly, which process is con-
tinued until it is found by testing that all the ammonia is driven off. The first
boiler is then emptied and the steam diverted to the second boiler, the former being
then ready for a second charge from the tower. Each of these boilers while being
thus filled has a pipe passing to a condensing coil, and in which during the filling a
quantity of crude ammonia is condensed, and is run into the gas liquor well. When
the boiler is filled this pipe is stopped. The steam from the boiler charged with
ammonia from the liquor is now carried off by a large pipe, and conducted into the
tower at nearly its bottom, and passes up through the aforesaid interstices, meeting
the descending liquor and taking up its volatile ammonia; and all this vapour or
steam so charged goes from the top of the tower to the blower, a leaden vessel con-
taining an acid solution of sulphate of ammonia, and to which sulphuric acid is
constantly added, and crystals of sulphate of ammonia are being constantly fished
out. The vapours being deprived of their ammonia by the acid are carried off into
a vessel which contains the coils of pipes above referred to, and in which therefore
the liquor is heated before being carried to the tower. These vapours are then
Price 2d1

page_text: passed through a series of upright pipes or condensers exposed to the atmosphere
until quite cooled, and all the water is condensed. The remaining gases, consisting of
carbonic acid and sulphuretted hydrogen, are then passed into a furnace over a coke
fire, and the sulphuretted hydrogen is burned and becomes sulphurous acid gas, and
is passed into ordinary vitriol chambers to be made into sulphuric acid in the usual
manner. From this gas so burned, and from which if allowed to escape a great
nuisance would arise, we produce a considerable proportion of the acid we require in
the manufacture of sulphate of ammonia.
Another part of our Invention consists in a method of purifying sulphuric acid
made from ores which contain so large a quantity of arsenic as to make it unfit for
the manufacture of sulphate of ammonia. This acid we place in two leaden tanks
of rather smaller depth than the acid solution in the blower, and into each of them
we bring a lead pipe from the top of the tower, and let the vapour blow into one of
them. The acid combines with the ammonia of the vapour and sets free the sul-
phuretted hydrogen, which combines with the arsenic and precipitates it as sulphide.
As soon as the slightest indication of sulphuretted hydrogen is felt, the vapour is
turned off or passed into the second tank. The first tank is now allowed to settle,
and the acid is drawn off into the blower fit for the manufacture of sulphate of
ammonia. The sulphide of arsenic may be removed as it accumulates, and being
freed from the acid may be used or thrown away.