Improvements in Utilising Acid Sulphates and Acids, and in Obtaining Nitric Acid and Hydrochloric Acid.
Year: 1894

page_text: Date of Application, 19th May, 1894
Complete Specification Left, 18th Feb., 1895-Accepted, 23rd Mar., 1895
PROVISIONAL SPECIFICATION.
Improvements in Utilising Acid Sulphates and Acids, and in
Obtaining Nitric Acid and Hydrochloric Acid.
We, ARCHIBALD CAMPBELL, of 42, Whittaker Road, Upton Park, in the
County of Essex, Chemist, and ALEXANDER WALKER, of Fernlea, Irvine, in
the County of Ayr, North Britain, Manufacturing Chemist, do hereby declare the
nature of this invention to be as follows, that is to say :--
Our said invention comprises improved operations or processes for utilising acid
sulphates and acids, and for obtaining nitric acid and hydrochloric acid.
In carrying out our invention we employ an acid sulphate such as what is known
as "nitre cake" and obtained in treating nitrate of soda with sulphuric acid for
obtaining nitric acid; or we employ an acid sulphate formed from inono-sulphate,
such as "salt cake" by adding comparatively dilute sulphuric acid or a mixture of
dilute sulphuric and nitric acids such as are residues of chemical operations or are
otherwise obtained. The mixture of sulphate and dilute acid is heated to drive off
the water or water and nitric acid, this being effected at a comparatively low
temperature, say about 300 degrees Fahrenheit.
4
In utilising the acid sulphate to obtain nitric acid we grind and intimately mix
together suitable proportions of nitrate of soda or of potash and the acid
sulphate, and heat the mixture to a suitable temperature, which may be from 600 to
800 degrees, Fahrenheit, in a vessel provided' with a mechanical agitator, and
with feeding and discharge appliances, the feeding being, by preference effected
continuously by means of a hopper and rotating screw. When commencing
operations there should be in the vessel a quantity of sulphate of soda or of potash:
already heated to the proper temperature. The entering mixture becomes rapidly
decomposed without fusing or becoming adhesive, nitric acid being evolved and
passing off through an outlet to condensers.
To obtain hydrochloric acid, we grind and intimately mix together in suitable
proportions the acid sulphate and common salt and treat the mixture in the same
way as for nitric acid.
"
The nitric acid or hydrochloric acid is by the hereinbefore described operations
obtained extremely free from air and moisture and delivered at a regular rate; and
is consequently very advantageously applicable for varicus chemical operations.
Dated this Eighteenth day of May 1894.
EDMUND HUNT,
Applicants' Agent..
Improvements in Utilising Acid Sulphates and Acids, and in
Obtaining Nitric Acid and Hydrochloric Acid.
We, ARCHIBALD CAMPBELL, of 42, Whittaker Road, Upton Park, in the
County of Essex, Chemist, and ALEXANDER WALKER, of Fernlea, Irvine, in the
County of Ayr, North Britain, Manufacturing Chemist, do hereby declare the nature
[Price 8d.]

page_text: of this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement, that is to say :-
Our said invention comprises improved operations or processes for utilising acid
Bulphates and acids, and for obtaining nitric acid and hydrochloric acid.
In carrying out our invention we employ an acid sulphate such as what is known
as "nitre cake" and obtained in treating nitrate of soda with sulphuric acid for
obtaining nitric acid; or we employ an acid sulphate formed from mono-sulphate,
such as.
"salt cake" by adding comparatively dilute sulphuric acid or a mixture of
dilute sulphuric and nitric acids such as are residues of chemical operations or are
otherwise obtained. The mixture of sulphate and dilute acid is heated to drive off
the water or water and nitric acid, this being effected at a comparatively low
temperature, say about 300 degrees, Fahrenheit.
In utilising the acid sulphate to obtain nitric acid we grind and intimately mix
together suitable proportions of nitrate of soda or of potash and the acid sulphate,
and heat the mixture to a suitable temperature which is from 400 to 450 degrees,
Fahrenheit, in a vessel provided with a mechanical agitator, and with feeding and
discharge appliances, the feeding being by preference effected continuously by
means of a hopper and rotating screw. When commencing operations there should
be in the vessel a quantity of sulphate of soda or of potash already heated to the
proper temperature. The entering mixture becomes rapidly decomposed without
fusing or becoming adhesive, nitric acid being evolved and passing off through an
outlet to condensers..
To obtain hydrochloric acid, we grind and intimately mix together in suitable
proportions the acid sulphate and common salt and treat the mixture in the same
way as for nitric acid, but heat it to a higher temperature namely from 600 to
800 degrees, Fahrenheit.
The nitric acid or hydrochloric acid is by the hereinbefore described operations
obtained extremely free from air and moisture and delivered at a regular rate; and
is consequently very advantageously applicable for various chemical operations.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
1. The obtaining of nitric acid by grinding and intimately mixing together
nitrate of soda or of potash and acid sulphate and heating the mixture to a suitable
temperature substantially as hereinbefore described.
2. The obtaining of hydrochloric acid by grinding and intimately mixing
common salt and acid sulphate and heating the mixture to a suitable temperature
substantially as hereinbefore described.
3. In combination with the process claimed in the first claim or with the process
claimed in the second claim the converting of salt cake or monosulphate into dry
acid sulphate by treating the same with dilute acid and evaporating substantially
as hereinbefore described.
Dated this Sixteenth day of February 1895.
EDMUND HUNT,
Applicants' Agent.