Improvements in and connected with the Manufacture of Iron Salts.
Year: 1893

page_text: Date of Application, 1st Apr., 1893
Complete Specification Left, 9th June, 1893-Accepted; 15th July, 1893
PROVISIONAL SPECIFICATION.
Improvements in and connected with the Manufacture of Iron Salts.
I, PETER HART of "Gransmoor" Fairfield, near Manchester in the County of
Lancaster, Chemist, do hereby declare the nature of this invention to be as
follows:-
:-
This invention relates to the manufacture by an inexpensive process of salts of
iron which may be employed in the treatment of sewage, in dyeing and printing,
and for other purposes.
In carrying out my invention I mix about 417 parts of ferrous sulphate (common
green copperas) either in crystals or in strong solution, with about 85 parts of
nitrate of soda or 101 parts of nitrate of potash, and 49 or more parts of mono-
hydrated sulphuric acid. This mixture is introduced into the nitre pots or ovens
attached to the pyrites or sulphur kilns which form part of a sulphuric acid plant,
and are subjected to heat in the ordinary manner employed in the manufacture
of sulphuric acid. The nitric acid evolved oxidises the ferrous sulphate to ferric
sulphate, and the nitrous oxides, (chiefly dioxide) which are also evolved, pass
into the vitriol chambers to take part in the production of sulphuric acid in the
usual manner.
There ultimately remains in the pots, a mixture of iron alum and
ferric sulphate, which may be run out or be otherwise transferred into drums or
trays in the well known manner, after which it sets into a solid or pasty mass.
Instead of employing substantially the proportions hereinbefore specified, more
or less sulphuric acid may be employed so as to obtain a more or less acid or
basic iron salt suitable for any especial use for which it may be intended.
Although I have for convenience specified monohydrated sulphuric acid, I may,
and in practic I prefer, to use an equivalent quantity of sulphuric acid of about
1-750 S.G. or in some cases even weaker acid, as may be determined by the heat
of the kilns and other local conditions. My object in any case is to have sufficient
water present or remaining in the product to retain it in such a fluid condition
that it may flow easily from the pots and afterwards set solid.
It is generally more convenient to put the material into the nitre pots as
described, but it is not absolutely necessary to do so as they may be equally
employed in an outside closed pot retort cylinder or the like, heated by coal or
other fuel, the gases evolved from the pots being conducted into the chamber in
any convenient manner by known means. Alternatively the gases evolved may
be mixed with air or other source of oxygen and by means of coke or other suit-
able columns, be converted into nitric acid in the manner at present well known and
commonly employed.
In substitution for the ferrous sulphate hereinbefore directed to be employed in
the preparation of the mixture, I may use about 590 parts of crystallised ferrous
chloride or its equivalent in strong solution. In this case the re-action is similar
but the residual salts are chiefly ferric chloride and iron alum.
Dated this 30th day of March A.D. 1892.
WILLIAM E. HEYS,
Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in and connected with the 'Manufacture of Iron Salts.
PETER HART, of "Gransmoor" Fairfield near Manchester in the County of
Lancaster, 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:-
This invention relates to the manufacture, by an inexpensive process, of salts of
iron which may be employed in the treatment of sewage, in dyeing and printing,
and for other purposes.
The
In carrying out my invention, I mix in the proportions of about six molecules
of ferrous sulphate, two molecules of a suitable nitrate, and one molecule of
sulphuric acid, and subject the mixture to heat in suitable pots retorts cylinders
or the like. The gases evolved are conducted away and utilised in the manufacture
of sulphuric acid, or in the manufacture of nitric acid, by known means.
residue in the vessels, is poured in a semi-fluid or pasty condition, into drums
trays or moulds, wherein it sets into a solid or semi-solid mass. In substitution for
the ferrous sulphate, ferrous chloride may be employed, and more or less sulphuric
acid may be used, according as a more or less acid or basic salt is required.
The ferrous sulphate may be used either in crystals or in strong solution, and
the sulphuric acid may either be the monohydrate, or, by preference, an equivalent
quantity of sulphuric acid of about 1.750 S.G. or even weaker acid as may be
determined by the heat of the kilns or by other local conditions. My object in
this case is to have sufficient water remaining in the residual product to retain it
in such a fluid condition that it may flow easily from the vessels in which the
mixture has been treated, and afterwards set solid.
The mixture of the various materials in about the molecular proportions herein-
before set forth is, when the vapours are to be utilised in the manufacture of
sulphuric acid, introduced into the nitre pots or ovens attached to the pyrites or
sulphur kilns which form part of a sulphuric acid plant, and is therein subjected
to the action of heat in the ordinary manner employed in the manufacture of
sulphuric acid. The nitric acid evolved oxidises the ferrous sulphate, and the
nitrogen oxides, (chiefly nitrogen dioxide), which are also evolved, pass into the
vitriol chambers to take part in the production of the sulphuric acid in the ordinary
manner. There ultimately remains in the pots, a mixture of iron alum and ferric
sulphate which may be run out or be otherwise transferred to the drums or trays
in the usual known manner, after which it sets into a solid or pasty mass on
cooling.
It is generally more convenient to put the materials into the nitre pots as
described, but it is not absolutely necessary to do so as they may be equally
treated in outside closed pots retorts cylinders or the like, heated by coal or other
fuel, the gases from the pots being conducted into the vitriol chamber in the
usual manner or by any known and suitable means. Alternatively, the gaseous
products or vapours evolved may be mixed with air or other source of oxygen,
and by means of coke or other suitable columns, be converted into nitric acid, in
the manner at present well known and commonly employed.
In substitution for the ferrous sulphate, herein before described, I may use
similar molecular proportions of ferrous chloride or its equivalent in strong
solution, in which case the residual product will be chiefly ferric chloride and
iron alum.
I prefer to use nitrate of soda as the source of nitric acid in the mixture,
because of its comparative cheapness, but I may employ, when conditions of price
and local convenience permit, nitrates of the other alkalies and alkaline earths or
of some of the commoner metals, but always in such proportions that there may
be about two molecules of the nitric acid therein for each group of six molecules

page_text: of the ferrous salt, and one molecule or more (or less) of the sulphuric acid in
the mixture to be treated for the production of the ferric salt and the nitrogen
fumes.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The hereinbefore described process for the production of ferric salts which
consists in subjecting to the action of heat a mixture of ferrous sulphate or ferrous
chloride sulphuric acid and a nitrate in about the molecular proportions specified,
in suitable vessels, and conducting the vapours or fumes liberated therefrom to a
vitriol chamber to be utilised in the manufacture of sulphuric acid, substantially as
set forth.
2. The hereinbefore described process for the production of ferric salts which
consists in subjecting to the action of heat a mixture of ferrous sulphate or ferrous
chloride sulphuric acid and a nitrate in about the molecular proportions specified,
in suitable vessels, and conducting the nitrogen fumes together with atmospheric
air or other source of oxygen to coke columns or the like for the production of
nitric acid, substantially as set forth.
3. In the manufacture of iron salts, subjecting a mixture of a ferrous salt
sulphuric acid and a nitrate to the action of heat in the nitre pots of an ordinary
sulphuric acid plant, in such a manner that the nitrogen vapours evolved may be
utilised in the vitriol chamber, substantially as herein before described.
4. In the manufacture of iron salts, subjecting a mixture of a ferrous salt a
nitrate and sulphuric acid to the action of heat in a closed pot retort or cylinder
and conducting the nitrous vapours evolved to a vitriol chamber for utilisation in
the usual manner in the manufacture of sulphuric acid, or to a coke column
or the like for the production of nitric acid, substantially as hereinbefore set
forth.
5. As a new article of manufacture, ferric salts capable of utilisation in the
treatment of sewage and for other purposes, produced by subjecting a mixture of
ferrous salt a nitrate and sulphuric acid to the action of heat by which nitrogen
oxides are liberated for use in the manufacture of sulphuric acid or of nitric acid,
substantially as hereinbefore described.
Dated this 8th day of June A D 1893.
WILLIAM E. HEYS,
Agent for the Applicant.