IMPROVEMENTS IN TREATING AMMONIACAL LIQUOR' PRODUCED FROM COAL IN MAKING GAS, AND OBTAINING USEFUL PRODUCTS FOR MAKING ARTIFICIAL MANURES
Year: 1858

page_text: PROVISIONAL SPECIFICATION left by Thomas Greenshields at the Office
of the Commissioners of Patents, with his Petition, on the 3rd April
1858.
I, THOMAS GREENSHIELDS, of No. 11, Little Titchfield Street, London, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
TREATING AMMONIACAL LIQUOR' PRODUCED FROM COAL IN MAKING GAS, AND
OBTAINING USEFUL PRODUCTS FOR MAKING ARTIFICIAL MANURES," to be as
follows:-
The usual method of decomposing the ammoniacal liquor is to add muriatic
or sulphuric acid to the ammoniacal liquor, or the ammoniacal liquor is
placed in a still and a quantity of caustic lime added, and the ammonia
driven off by heat, and the vapours condensed in a tank or cistern con-
taining either muriatic or sulphuric acid as a muriate or sulphate was
required. The Invention has for its object improvements in treating the
ammoniacal liquor to obtain the salts of ammonia, from which may be
obtained other products for making artificial manures; and the Invention
consists in first subjecting the ammoniacal liquor to the action of sulphate of
lime reduced to powder. For this purpose a known quantity, by weight, of
sulphate of lime is put into a suitable iron vessel, to be called a decomposing
pan. The quantity of sulphuric acid contained in the sulphate of lime can be
ascertained by known means; a known quantity, by measure, of ammoniacal
liquor is to be run into the decomposing pan until full; the liquor is to be well
mixed with the sulphate of lime and remain three or four hours, or until decom-

page_text: posed, and the carbonate of ammonia become a sulphate of ammonia, and this
may be known by subjecting the liquor to any of the well-known tests; when
so decomposed it is to be run off the lime into an evaporating pan or an evapo-
rating furnace, to be treated as herein-after directed. A fresh quantity of the
ammoniacal liquor is to be run into the decomposing pan, and treated as
before described. The number of gallons of ammoniacal liquor required to
decompose the sulphate of lime in the decomposing pan can be ascertained
by finding the quantity of ammonia that is contained in a gallon, when the
number of gallons of ammoniacal liquor can be estimated that will be
required to furnish the known quantity of ammonia that will combine with
the sulphuric acid in the sulphate of lime in the decomposing pan; but it is
preferred to have the sulphate of lime in excess of the equivalents to ensure
the decomposition of the carbonate of ammonia contained in the ammoniacal
liquor. The liquor run from the decomposing pan contains liquid sulphate of
ammonia, bydrosulphuret, of ammonia, tar, and other impurities. To decom-
pose the hydrosulphuret of ammonia, sulphuric acid is to be cautiously added
to the liquor until sulphureted hydrogen gas ceases to be evolved; to prevent
the evolved gas causing a nuisance, it should be collected and conducted by
a pipe to the door of a furnace and burned; when all the gas has been
evolved, a small portion of sulphate of lime in powder is to be added to the
liquor, and heat applied to evaporate the liquor to about half the quantity
(during the operation frequently skim off from the surface the impurities that
arise), when it must be allowed to settle, and then run from off the impurities
into another evaporating pan, and a little more sulphate of lime added, and the
.evaporation continued until the whole of the tar is removed or precipitated
with the lime, when settled to be run off into a clean pan, and allowed to
crystalise, or evaporated to a salt. In some cases, it is preferred, when the
liquid sulphate is deprived or nearly deprived of tar, to add as may be most
suitable sawdust, fine ashes, or spent tan reduced to powder; and evapó-
rate the mixture to dryness. In some cases when the liquid sulphate is
nearly concentrated and deprived of tar, to run it into a clean pan, and add
the equivalent of common salt in fine powder to form a sulphate of soda and
muriate of ammonia, and either seperate the salts by well-known means or
evaporate the liquid to a combined salt, either with or without the addition of
sawdust, bran, the husks of seeds, or spent grains from breweries or distilleries.
In some cases it is preferred, when the decomposition of the common salt and
the liquid sulphate of ammonia is complete, to add bran, husks of seeds, spent
grains, calcined flints, or similar substances, prepared either seperately or
together (by boiling in caustic alkali and reduced to nearly or quite a dry

page_text: state), and evaporate the mixture as before described. When it is desired to
make a muriate of ammonia and sulphate of soda, the sulphate of soda to be
used for making a carbonate of soda, it is preferred to use the liquor after
being treated in the first evaporating pan, and after being run into the second
evaporating pan to add the equivalent of common salt, and concentrate the
liquor, and remove the crystals of sulphate of soda as they form, combined
with the tar and other impurities, and then concentrate and crystalise the
muriate of ammonia; the impurities in the sulphate of soda will be removed
in converting the sulphate into carbonate of soda by well-known means. It
is preferred, when evaporating pans are used, that suitable means be adopted
to prevent the vapours from the pans escaping into the atmosphere. The
lime when removed from the decomposing pans will contain carbonate of lime,
some sulphate of ammonia, and some undecomposed sulphate of lime, to these
is to be added some dry fine ashes or sawdust to absorb the moist sulphate of
ammonia, some fine ashes or sawdust saturated with sulphate of ammonia or
sulphate of soda, or equal portions of both, and mixed with the lime in the
proportion of one-fifth of the saturated mixture to four-fifths of the lime, or in
any other proportion that may be required, and reduced to powder to form
an artificial manure. The other salts, either singly or combined, or the
saturated materials before described, being for the purpose of mixing with
other prepared muriates, silicates, or phosphates, either mixed after being
manufactured or added to the alkaline salts during the process of being
manufactured; the composition of the mixture to form an artificial manure
will depend on the peculiarity of the soil and the known constituents of the
crop to be grown.