AN IMPROVED PROCESS FOR OBTAINING SALTS OF SODA AND OTHER ALKALIES stanna
Year: 1858

page_text: ealed the 25th March 1859, and dated the 8th October 1858.
PROVISIONAL SPECIFICATION left by the said Thomas Roberts and John
Dale at the Office of the Commissioners of Patents, with their Petition,
'on the 8th October 1858.
We, THOMAS ROBERTS and JOHN DALE, of Manchester, in the County of
Lancaster, Manufacturing Chemists; do hereby declare the nature of the said
Invention for AN IMPROVED PROCESS FOR OBTAINING SALTS OF SODA AND OTHER
ALKALIES to be as follows:-
Our Invention consists of an improved method for producing nitrite,
arseniate, and stannate of soda or other alkalies. We produce nitrite of soda
or other alkalies by passing the waste oxynitrogenous gases given off in the
preparation of arsenic acid from nitric acid and arsenious, as also from other
chemical operations; and this we effect by agitating the said oxynitrogenous
gases in contact with soda, or other alkalies, or by making these gases to pass
through these alkalies or their combinates.
We produce aŕséniatés of soda and other alkalies by making arsenic acid
with soda or other alkalies, or we add arsenic acid to the chlorides of these
alkalies, whereby we produce arseniates and muriatic acid. We produce
arseniate of ammonia by conducting ammonia produced in a subsequent
[Price 8d.j

page_text: operation into arsenic acid, or we use arsenic acid for the purification of coal
gas from ammonia, or we add arsenic acid to crude gas water containing
ammonia, whereby we produce arseniate of ammonia.
We produce stannate of soda and other alkalies by boiling mettallic tin with
nitrite of soda and other alkalies, to which is added free soda or other alkali,
whereby the nitrite is decomposed, furnishing in contact with the tin, stamic
acid and free ammonia, which we collect or conduct into arsenic acid, the stamic
acid combining with the alkali, and producing a stannate of the alkali employed;
or we also produce stannate of soda or other alkalies by boiling waste tin
plate, known as scrap tin, with a mixture of nitrite of soda or other alkalies,
whereby the whole of the tin is removed from the scrap tin, and converted
into stamate of soda or other alkalies.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Roberts and John Dale in the Great Seal Patent
Office on the 8th April 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, THOMAS
ROBERTS and JOHN DALE, of Manchester, in the County of Lancaster, Manu-
facturing Chemists, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of October, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
us, the said Thomas Roberts and John Dale, Her special licence that we,
the said Thomas Roberts and John Dale, our executors, administrators, and
assigns, or such others as we, the said Thomas Roberts and John Dale, our
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "AN IMPROVED PROCESS
FOR OBTAINING SALTS OF SODA AND OTHER ALKALIES," upon the condition (amongst
others) that we, the said Thomas Roberts and John Dale, our executors or
administrators, by an instrument in writing under our, or their, or one of our
or their hands and seals, should particularly describe and ascertain the nature
of the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that we, the said Thomas Roberts and John Dale,
do hereby declare the nature of our said 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 Invention consists of an improved method or methods for producing
nitrite, arseniate, and stannate of soda or potash or other alkalies. And our
process for producing nitrites of the alkalies consists in passing the nitrogenous
gases evolved in the manufacture of arsenic acid from nitric acid and arsenious
acid; and this we effect by pouring upon arsenious acid (contained in a suit-
able vessel) a quantity of nitric acid, sufficient to convert the arsenious acid
into arsenic acid. The evolved nitrogenous gases are made to pass into the
alkalies or their carbonates, but we prefer to use the alkalies in the caustic
state. The vessel containing the alkalies is provided with agitators, so as
more effectually to mingle the nitrogenous gases with the alkaline solution;
or we pass the nitrogenous gases into a tower, through which is made to flow
the alkalies in question, whereby we produce nitrites of the alkalies employed,
or we produce nitrites of the alkalies in the manner following:-Nitrate of
soda or potash mixed in the proportion of two equivalents of chloride, one
equivalent of nitrate, and three equivalents of sulphuric acid, whereby we
obtain a sulphate of the alkali employed, and there is evolved nitrous gas and
chlorine; these mixed gases are conducted into a solution of sulphuric acid, of
the density of 1'50, or thereabouts. The nitrous gases (as is well known) are
absorbed by the solution of sulphuric acid, whilst the chlorine, not being
absorbed, passes out, and may be combined with lime for the production of
chloride of lime. The solution of nitrous gas in the sulphuric acid is now
liberated by the dilution of solution of sulphuric acid with a quantity of water,
whereby the whole of the contained nitrogenous gases are liberated and con-
ducted into a solution of the alkali employed for the production of the nitrite.
The diluted solution of sulphuric acid may be now concentrated, and again
used for the purpose of another operation.
We also produce nitrite of soda or other alkalies by passing the waste
nitrogenous gases (arising from other sources of chemical manufacture, as in
the manufacture of picric acid, or in the oxydation of the proto-sulphates of
iron by means of nitric acid) into solutions of the alkalies.
Our improvements further consist in a method or methods for producing
arseniates of soda, potash, or other alkalies; and this we effect in the manner
following: We take chloride of sodium, chloride of potasium, or chloride of
ammonium, in a suitable vessel, (and the vessels we use are such as are well
known to manufacturing chemists for the production of nitric or muriatic acid,)

page_text: and add to any such chloride so much arsenic acid in solution as shall be suffi-
cient to decompose these chlorides, whereby we obtain arseniates of the alkalies
employed and solutions of muriatic acid; or we take nitrates of the alkalies,
whereby we obtain arseniates of the alkalies and liberated nitric acid; or
we obtain arseniate of ammonia by using arsenic acid, for the purpose of the
purification of coul gas from ammonia; or we use crude gas liquor, to which
we add so much of a solution of arsenic acid as shall be sufficient to form such
arseniate of ammonia as shall be required.
Our improvements further consist in a method for obtaining the salt known
as stannate of soda; and this we obtain in the manner following:-We take
metallic tin, to which we add a solution of caustic potash or soda; these are
brought up to the boiling point in an iron vessel; we now add so much nitrite
of soda as shall be sufficient to effect the solution of the tin. The metallic
tin is rapidly oxydized by the decomposition of the nitrite employed, whereby
is produced stannic acid and ammonia; the ammonia is collected or conducted
into arsenic acid, and the stannic acid combining with the soda or other
alkali, producing stannate of such alkalies. The proportions we use are such
as shall furnish one equivalent of stannic acid to one equivalent of alkali, and
sufficient nitrite as shall be required for the complete oxydation of the tin.
We also produce stannates of the alkalies by boiling waste tin plate (com-
monly known as scrap tin) with a mixture of a nitrite of an alkali and free
alkali, whereby the whole of the metallic tin is removed from the scrap tin,
and converted into a stannate of the alkali employed.
In witness whereof, we, the said Thomas Roberts and John Dale, have
hereunto set our hands and seals, this Seventh day of April, in the
year of our Lord One thousand eight hundred and fifty-nine.
THU. ROBERTS
JOHN DALE.
Signed, sealed, and delivered by the above-
named Thomas Roberts and John Dale,
in the presence of
RD K. COOPER,
A commissioner to administer oaths in Chancery in England.
(L.S.)
(L.S.)