Improvements in Treating Nitrates for the Production of Nitrio Acid and the Recovery of Bye-products.
Year: 1895

page_text: Date of Application, 12th Dec.,
1895
Complete Specification Left, 8th Feb., 1896-Accepted, 21st Mar., 1896
PROVISIONAL SPECIFICATION.
Improvements in Treating Nitrates for the Production of Nitrio
Acid and the Recovery of Bye-products.
We, ROBERT MAIN, of Ardeer Cottage, Stevenston, Ayrshire, Iron Works
Manager, and WILLIAM DONALD, of Canal Street, Saltcoats, Ayrshire, Analytical
and Practical Chemist, do hereby declare the nature of this invention to be as
follows:-
This invention has for its object the economical production of nitric acid from
nitrate of soda or other nitrates and the recovery of bye-products resulting from
the process of treatment.
Nitrate of soda and manganic oxide, intimately mixed, are heated in a muffle
furnace and decomposed.
i
The evolved oxides of nitrogen are mixed with air and conducted into a trickling
tower, or other suitable oxidizing system, charged with nitric acid and water, and
therein converted into nitric acid.
When nitric acid of a high density is desired, the nitric acid from the oxidizer is
mixed with as much sulphuric acid as will combine with the free water.
On the application of a regulated heat to the mixed acids, nitric acid distills over
and is collected.
By submitting the retorts to a higher temperature the water is distilled from the
sulphuric acid, and is collected separately. This water may be returned to the
oxidizer; and the sulphuric acid may be again used with a fresh charge of nitric
acid.
The furnaced product consists of soda and manganous oxide. This is treated
with water, steam, and air-blowing.
The soda is converted into hydrate, and the manganous oxide to manganic
oxide.
The caustic soda solution is withdrawn and used as may be desired.
The deposited manganic oxide is washed, and prepared to be used on a fresh
charge of nitrate of soda.
In some instances it may be advantageous to add a quantity of weak nitric acid
to the charge of nitrate of soda and manganic oxide, with a preliminary heating,
before furnacing.
;1..
The distillation may be performed in glass retorts, preferably in a continuous
system.
In lieu of nitrate of soda there may be used any analogous nitrate, and nickelic,
or cobaltic oxide may be substituted for the manganic oxide.
Dated this 11th day of December 1895.

page_text: Improvements in Treating Nitrates for the Production of Nitric
Acid and the Recovery of Bye-products.
We, ROBERT MAIN, of Ardeer Cottage, Stevenston, Ayrshire, Iron Works
Manager, and WILLIAM DONALD, of Canal Street, Saltcoats, Ayrshire, Analytical
and Practical 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 has for its object the economical production of nitric acid from
nitrate of soda or other nitrates and the recovery of bye-products resulting from
the process of treatment.
Nitrate of soda and manganic oxide, intimately mixed; are heated in a muffle
furnace to effect their decomposition.
7
The mixture of nitrate of soda and manganic oxide may consist of equal parts
by weight, but we do not bind ourselves. to these proportions, as in practice other
proportions may be found to be sufficient or more advantageous.
The evolved oxides of nitrogen are mixed with air and conducted into a trickling:
tower, or other suitable oxidising system, charged with nitric acid and water, and
therein converted into nitric acid.
When nitric acid of a high density is desired, the nitric acid from the oxidizer
may be mixed with as much sulphuric acid as will combine with the free water.
On the application of a regulated heat to the mixed acids, nitric acid distils over
and is collected. By submitting the retorts to a higher temperature, the water is
distilled from the sulphuric acid, and is collected separately.. This water may be
returned to the oxidizer; and the sulphuric acid may be again used with a fresh
"charge of nitric acid.
The furnaced product consists of soda and manganous oxide. This is treated.
with water, steam, and air-blowing. The soda is converted into hydrate, and the
manganous oxide to manganic oxide. The caustic soda solution is withdrawn and
used as may be desired. The deposited. manganic oxide is washed, and prepared
to be used on a fresh charge of nitrate of soda.
In some instances it may be advantageous to add a quantity of weak nitric acid
to the charge of nitrate of soda and manganic oxide, with a preliminary heating,
before furnacing.
The distillation may be performed in glass. retorts, preferably in a continuous
"system.
In lieu of nitrate of soda there may be used any analogous nitrate, such as:
nitrate of potash.
י.
Nickelic, cobaltic or other metallic oxide capable of parting with part of its
oxygen and of combining with the alkali may be substituted for the manganic
oxide.
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 herein described process of treating nitrates for the production of nitric
acid and the recovery of bye products.
2. The production of nitric acid from nitrate of soda or other nitrate by heating
an intimate mixture of the nitrate and manganic oxide or analogous oxide to effect
decomposition and conducting the evolved oxides of nitrogen through an oxidizing
system charged with nitric acid and water substantially as described.

page_text: 3. In the manufacture of nitric acid by heating and decomposing nitrate of soda
or other nitrate and manganic oxide or analogous oxide, producing a residue of
alkali and oxide corresponding to the nitrate and oxide employed and recovering
them separately as described.
Dated this 7th day of February 1896.
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62 St. Vincent Street, Glasgow, Agent for the Applicants.