IMPROVEMENTS IN THE MANUFACTURE OF SULPHATE OF AMMONIA as
Year: 1884

page_text: I WILLIAM ALFRED MEADOWS of Rainhill in the County of Lancaster, Manu-
facturing Chemist, do hereby declare the nature of my said invention for
"IMPROVEMENTS IN THE MANUFACTURE OF SULPHATE OF AMMONIA to be as
follows:-
:-
"
My invention relates to the manufacture of sulphate of ammonia by passing
gaseous ammonia into dilute sulphuric acid.
Hitherto in such manufacture it has been necessary in order to obtain white
crystals to use sulphuric acid free from impurities such as arsenic and iron,
otherwise discolored and dirty crystals were produced; and in order to obtain
white crystals it was necessary to use acid made from the combustion of sulphur or
other material capable of producing puro acid. Pyrites or like acid was only
applicable for the production of discolored and inferior crystals unless it had first
undergone a costly process for the elimination of arsenic and iron.
Now the object of my invention is to so conduct the manufacture of sulphate of
ammonia that common pyrites or like acid can be used and pure white crystals of
sulphate obtained.
My invention consists essentially in adding a small quantity of coal tar or
equivalent substance to the dilute sulphuric acid used in the manufacture of sulphate
of ammonia whilst the gaseous ammonia is being absorbed and in removing the
scum which rises to the top of the said acid during absorption before the sulphate
crystals are formed.
In practice I dilute common pyrites acid of about 150° T. with about three times
its weight of water and pass gaseous ammonia obtained in any usual or suitable
manner into the said dilute acid until a temperature of about 100 F. is reached, at
this stage I add about 1/6th per cent of coal tar. As the absorption of the ammonia
by the acid proceeds a scum containing the arsenic and iron is thrown up and is
removed by skimming: In about two or three hours when no more scum rises and
the liquid is clear the sulphate of ammonia pure white crystals begin to form: they
are fished out and the process is continued in the usual manner.
Dated this twenty sixth day of March 1884.*
J. T. KING,
Agent for the Applicant.

page_text: I, WILLIAM ALFRED MEADOWS of Rainhill in the County of Lancaster, Manu-
facturing Chemist, do hereby declare the nature of the said invention for
IMPROVEMENTS IN THE MANUFACTURE OF SULPHATE OF AMMONIA" and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:―
My invention relates to the manufacture of sulphate of ammonia by passing
gaseous ammonia into dilute sulphuric acid.
Hitherto in such manufacturo it has been necessary in order to obtain white
crystals to use sulphuric acid free from impurities such as arsenic and iron,
otherwise discolored and dirty crystals were produced; therefore when white
crystals were desired it was necessary to employ at great expense acid made from
the combustion of sulphur or other material capable of producing pure-acid.
Pyrites or like acid was only applicable to the production of discolored and
inferior crystals, unless it had first undergone a costly process for the elimination
of arsenic and iron.
Now the object of my invention is to so conduct the manufacture of sulphate of
ammonia that common pyrites or like acid can be used and pure white sulphate of
ammonia crystals obtained.
My invention consists essentially in adding a small quantity of coal tar or
equivalent substance as regards action, to the dilute sulphuric acid used in the
manufacture of sulphate of ammonia whilst the gaseous ammonia is being absorbed ;
and in removing the scum which rises to the top of the said acid during absorbtion
before the sulphate of ammonia crystals are formed.
In carrying my invention into practice I dilute common pyrites acid of about
150° T with about three times its weight of water and pass gaseous ammonia
obtained in any usual or suitable manner into the said dilute acid until a
temperature of about 100° F. is reached; at this stage I add about 1/6th per cent of
coal tar. As absorbtion of ammonia by the acid proceeds a scum containing the
arsenic and iron is thrown up and is removed by skimming. In about two or three
hours when no more scum rises and the liquid is clear pure white sulphate of
ammonia crystals begin to form and are fished out, the process is then continued
in the usual manner.
Instead of coal tar, like products such as shale tar, stockholm tar, Archangel tar,
Stearino tar and other mineral animal or vegetable tars may be successfully used
in about the same proportions.
Various pitches may also be used in place of coal tar in slightly modified
proportions though less advantageously, namely coal tar pitch, asphalte pitch,
Bitumen pitch, Stearine pitch, wood pitch, resin pitch, paraffin pitch and like
pitches.
The following substances also act in manner similar to coal tar and may be
substituted therefor but I do not approve, with some exceptions, of their use,
namely resin and resinous substances, light oil, dead oil, resin oil, tar oil, anthracine
oil, paraffin oil, petroleum oil, and like oils, coal tar naphtha, and wood naphtha,
creosote and like substances, Tallow and animal oils and fats. Palm and other
vegetable oils and grease.
Amongst the various substances above mentioned some produce better and purer
crystals than others more especially the tars, dead oil, anthracine oil and creosote.
The more heavy and tenacious substances as a rule act the best. When pitches

page_text: resins and like solid or nearly solid substances are used they must be melted ground
powdered or otherwise treated so as to admit of being intimately mixed with the
dilute sulphuric acid.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
The improved manufacture of sulphate of ammonia substantially as herein set
forth.