Year: 1887

page_text: Date of Application, 21st Mar,, 1887
Complete Left, 21st Dec., 1887
Complete Accepted, 27th Jan., 1888
I, JOHN TAYLOR, of 3 Paragon Terrace, Cheltenham, in the County of Gloucester,
Chemist, do hereby declare the nature of this Invention to be as follows, that is
to say :-
My said Invention has for its object the manufacturing of nitric acid in an improved
and economical manner, the process yielding by-products the value of which reduces
the cost of the nitric acid.
In carrying out my Invention I mix ferrous sulphate (known as green vitriol) in
suitable proportion with sodium nitrate or potassium nitrate, and I heat the mixture in
a convenient vessel. Nitrous fumes are evolved and are passed into water in which
they become converted into nitric acid. The residue consisting of ferric oxide and
sodium sulphate or potassium sulphate is lixiviated with water to dissolve the sulphate
and the solution is separated from the insoluble ferric oxide. The ferric oxide is
usable as a pigment or otherwise; and the sulphate solution can be concentrated to
yield the sulphate in crystals which may be utilised in any known way.
Dated this Nineteenth day of March 1887.
EDMUND HUNT,
Applicant's Agent.

page_text: Improvements in the Manufacture of Nitric Acid.
1. JOHN TAYLOR of 3 Paragon Terrace Cheltenham in the County of Gloucester
Chemist, do hereby declare the nature 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:-
The object of this invention is to manufacture nitric acid in an improved and
economical manner the process also yielding byeproducts of a certain value.
The invention consists in mixing uncalcined ferrous sulphate containing all its
water of crystallization (commonly known as copperas or green vitriol) or uncalcined
ferric sulphate commonly called coquimbite with a suitable proportion of sodium nitrate
(Chili saltpetre) or potassium nitrate and heating the mixture in a suitable vessel until
the nitric acid vapours are evolved said vapours being carried off and condensed in
the usual manner while any nitrogen tetroxide evolved or formed may be passed into
what is known as a Lunge's recovery tower and there converted into nitric acid.
By experiment I judge that about 3 parts by weight of ferrous sulphate to about
17 parts of sodium nitrate or to 2 parts of potassium nitrate will give good results,
and an even better result will be obtained by the use of a mixture of 1 part by weight
of ferric sulphate to 9 of sodium nitrate or 11 of potassium nitrate. The vessel in
which the mixture is heated to a low red heat may be of any convenient form and
may be made of any substance which will not injuriously affect or be affected by the
materials treated.
The residue remaining in the vessel after the nitric acid vapours have been driven
off, will consist of ferric oxide and sodium or potassium sulphate as the case may be,
said residue is lixiviated with water to dissolve the sulphate and the solution is
separated by decantation or otherwise from the insoluble ferric oxide. The said ferric
oxide may then be used as a pigment, while the solution being evaporated to dryness,
sodium or potassium sulphate in the solid form will be obtained and may be utilized in
any known way.
I am aware that in the manufacture of nitric acid, calcined "ferrous sulphate" bas
'been used and nitrogen tetroxide obtained and condensed in water, but calcination
changes the character of ferrous sulphate by driving off the water of crystallization
and part of the sulphuric acid, a further disadvantage being that the high temperature
required to obtain the nitrous compounds from a mixture of calcined ferrous sulphate
and the particular nitrate, decomposes a portion of the nitric acid and consequently
the yield of such acid is not so great as by my process in which a portion of the
hydrogen contained in the water of crystallization of the ferrous sulphate is transferred
to the nitric acid radicle of the sodium or potassium nitrate, while the low heat at
which I am enabled to carry out my process enables me to obtain a large quantity of
nitric acid with but a small proportion of nitrogen tetroxide.

page_text: 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
1st. The improvements in the manufacture of nitric acid herein before described
consisting in treating a mixture of uncalcined ferrous sulphate or of ferric sulphate
with sodium or potassium nitrate substantially as set forth.
2nd. The manufacture of nitric acid ferric oxide and sodium or potassium sulphate
as herein before described consisting of heating a mixture of uncalcined ferrous sulphate
or ferric sulphate and sodium or potassium nitrate, driving off the nitric acid vapours
lixiviating the residue with water to dissolve the sulphate, and separating the solution
from the ferric oxide, and evaporating said solution to produce the sodium or potassium
sulphate all substantially as set forth.
Dated this 17th day of December 1887.
PHILIP M. JUSTICE,
55 & 56, Chancery Lanc, London,
Applicant's Agent.