AN IMPROVED PROCESS OF MANUFACTURING SULPHATE OF LEAD, CARBONATE OF LEAD, NITRATE OF POTASH, AND SULPHATE OF SODA
Year: 1859

page_text: LETTERS PATENT to William Edward Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Civil Engineer, for the
Invention of "AN IMPROVED PROCESS OF MANUFACTURING SULPHATE OF LEAD,
CARBONATE OF LEAD, NITRATE OF POTASH, AND SULPHATE OF SODA."-A
communication from Samuel Cooper, of Boston, in the United States of
America.
Sealed the 27th May 1859, and dated the 1st April 1859.
PROVISIONAL SPECIFICATION left by the said William Edward Newton
at the Office of the Commissioners of Patents, with his Petition, on
the 1st April 1859.
I, WILLIAM EDWARD NEWTON, of the Office for Patents, 66, Chancery
Lanc, in the County of Middlesex, Civil Engineer, do hereby declare the
nature of the said Invention for "AN IMPROVED PROCESS OF MANUFACTURING
SULPHATE OF LEAD, CARBONATE OF LEAD, NITRATE OF POTASH, AND SULPHATE OF
SODA," to be as follows:-
The first branch of this Invention is based upon the fact, that while metallic
lead is soluble in either acetic or nitric acid, it is insoluble in sulphuric acid,
and also upon the fact that this metal has a much greater affinity for sulphuric
than for either of the before-mentioned acids. This part of the Invention
consists in dissolving the lead in acetic or nitric acids, and in decomposing the
soluble nitrate or acetate thus formed by means of sulphuric acid, by which
means an insoluble precipitate of sulphate of lead is formed, the nitric or

page_text: acetic acids being set free to be used in dissolving another portion of lead. To
facilitate the operation of dissolving the lead, the latter is to be finely divided
or granulated, or in sono way reduced to thin sheets or grains. It is necessary
to employ an excess of lead to ensure the saturation of the nitric acid and
sufficient sulphuric acid to effect the entire decomposition of the nitrate of
lead. In lieu of nitric acid, acetic acid may be employed for the purpose of
dissolving the lead, the resulting acetate being dissolved, as in the case of the
nitrate by sulphuric acid, which again sets free the acetic acid for future use
as before. The nitric acid may be obtained for the solution of the lead by
decomposing nitrate of soda with the sulphuric acid employed in the process
as follows:-A saturated solution of nitrato of soda in water is decomposed by
sulphuric acid, which is added in sufficient quantity and of sufficient strength
for the purpose. The nitric acid of the nitrate of soda is thus set free, and
sulphate of soda is formed. The whole is then heated to 200° in pots of stone-
ware or enamelled iron, and metallic lead is introduced which will be rapidly
dissolved by the nitric acid, the nitrate of lead thus formed being forthwith
decomposed by the sulphuric acid of the sulphate of soda, an insoluble preci-
pitate of sulphate of lead, and a solution of nitrate of soda being the result.
As the sulphuric acid is expended it is replenished from time to time, and
when the lead is all dissolved, the liquid nitrato of soda is decanted upon a
new portion of lead to be treated with a fresh supply of acid, thus using
continuously the same solution of nitrate of soda with renowed portions of
sulphuric acid and lead as before.
The second branch of this Invention consists in decomposing the sulphate
of lead by means of carbonate of potash and nitrate of soda, whereby are
obtained carbonate of lead, nitrate of potash, and sulphate of soda. A double
decomposition takes place, from which results sulphate of potash, and carbonate
of lead, the latter being an insoluble precipitate may be separated from the
solution of sulphate of potash by decanting or drawing off. The sulphate of
potash is now decomposed. by the addition of nitrate of soda, saltpetre and
sulphate of soda being the result; the two salts are then separated by
crystallization. The materials employed are thus all converted into merchant-
able products, viz., carbonate of lead (the white lead of commerce), nitrate of
potash (saltpetre), and sulphate of soda (Glauber salts). If preferred, the
nitrate of soda may be first decomposed by pearlash them together in water,
the result being nitrato of potash and carbonate of soda, the former to be
separated by crystallization. The carbonate of soda is then employed to
decompose, the sulphate of lead, and the result as before is carbonate of lead,
nitrate of potash, and sulphate of soda or the nitrate of soda, the sulphate of
.

page_text: lead, and the pearlash may be mixed together, whereupon a triple decom-
position will take place. The carbonic acid of the pearlash uniting with the
lead, the nitric acid of the nitrate of soda with the potash, and the sulphuric
acid of the sulphate of lead combining with the soda, and forming, as before,
carbonate of lead, nitrate of potash, and sulphate of soda.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Edward Newton in the Great Seal Patent Office on
the 28th September 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the County
of Middlesex, Civil Engineer, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her I.etters
Patent, bearing date the First day of April, in the year of our Lord
1859, in the twenty-second year of Her reign, did, for Herself, Her heirs
and successors, give and grant unto me, the said William Edward Newton,
Her special license that I, the said William Edward Newton, my executors,
administrators, and assigns, or such others as I, the said William Edward
Newton, my 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 mako, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention of "AN IMPROVED PROCESS
OF MANUFACTURING SULPHATE OF LEAD, CARBONATE OF LEAD, NITRATE OF POTASH,
AND SULPHATE OF SODA," being a communication from Samuel Cooper, of
Boston, in the United States of America, upon the condition (amongst
others) that I, the said William Edward Newton, by an instrument in writing
under my hand and seal, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be: per-
formed, 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.
.
"
NOW KNOW YE, that I, the said William Edward Newton, do hereby
declare the nature of the 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) :—.
The first branch of this Invention is based upon the fact, that while metallic

page_text: lead is soluble in either acetic or nitric acid, it is insoluble in sulphuric acid,
and also upon the fact that this metal has a much greater affinity for sulphuric
than for either of the before-mentioned acids. This part of the Invention consists
in dissolving the lead in acetic or nitric acids, and in decomposing the solublo
nitrate or acetate thus formed by means of sulphuric acid, by which means an'
insoluble precipitate of sulphate of lead is formed, the nitric or acetic acids
being set free to be used in dissolving another portion of lead.
To facilitate the operation of dissolving the lead the latter is to be finely
divided, or in some way reduced to thin sheets or grains. The following
method has been found to answer this purpose:-Melt metallic lead, and pour
it through a perforated vessel into water; the lead is thus reduced to a finely
divided state, and in this state it is placed in a vessel of wood or other suitablo
material; the vessel is then charged with a sufficient quantity of diluted nitric
acid to cover the lead which is immediately attacked thereby. After standing
for some time the acid is drawn off upon a quantity of similarly prepared lead
in a second vessel where it is allowed to stand as before a short time, with tho
lead; it is then again drawn off upon a third quantity of lead in another vessel
and here it is allowed to stand as before. The neutral nitrate of lead is now
treated with sulphuric acid, which is added gradually until the nitrate is . all
decomposed, an insoluble sulphate being formed which is precipitated while
the nitric acid is again set free. The latter is then drawn off from the sulphate
of lead, and is returned to the original tub of the series to act upon a fresh
supply of lead. The nitric acid is thus constantly made available for the
continuance of the operation, and may be used over and over again, until lost.
by wastage, or weakened or deteriorated by foreign substances introduced by
the agents employed.
It is obvious that a greater or less number of tubs may be employed in a
series, the operation of dissolving the lead being greatly hastened by the
successive drawings off and the consequent exposure of the lead to the action
of the atmosphere. It is also evident that the proportions and quantity of the
various materials are not rigid, and that these will vary with their respective
strength and purity, it being necessary to employ each time an excess of lead
to ensure the saturation of the nitric acid, and sufficient sulphuric acid to effect
the entire decomposition of the nitrate of lead; the latter part of the operation
being easily tested as it proceeds. In lieu of nitric acid, acetic acid may be
employed for the purpose of dissolving the lead, the resulting acetate being
dissolved, as in the case of the nitrate, by sulphuric acid, which again sets free
the acetic acid for future use as before.
The above process may be modified without departing from the spirit of the

page_text: Invention, and the nitric acid be obtained for the solution of the lead by
decomposing nitrate of soda with the sulphuric acid employed in the process as.
follows:-A saturated solution of nitrate of soda in water is decomposed by.
sulphuric acid, which is added in sufficient quantity and of sufficient strength.
for the purpose, it being easy to determine the quantity required in each case
by testing as the operation proceeds. In general 30 to 40 lbs. of sulphuric acid
of a strength of 66 per ct. being sufficient to decompose 100 lbs. of the nitrate:
of soda of commerce. The nitric acid of the nitrate of soda is thus set free,
and sulphate of soda is formed. The whole is then heated to 200° in pots of
stoneware or enamelled iron, and metallic lead is introduced, which will be
rapidly dissolved by the nitric acid, the nitrate of lead thus formed being.
forthwith decomposed by the sulphuric acid of the sulphate of soda, an insoluble
precipitate of sulphate of lead and a solution of nitrate of soda being the result.
As the sulphuric acid is expended it is replenished from time to time, and'
when the lead is all dissolved the liquid nitrate of soda is decanted upon a
new portion of lead to be treated with a fresh supply of acid, thus using con-
tinuously the same solution of nitrate of soda with renewed portions of
sulphuric acid and lead as before.
The second branch of this Invention consists in decomposing the sulphate of
lead as above obtained by means of carbonate of potash and nitrate of soda
whereby are obtained carbonate of lead, nitrate of potash, and sulphate of
soda. For this purpose 25 lbs. of sulphate of lead are added to a saturated
solution of 10 lbs. of pearlash in water, a double decomposition taking place,
from which results sulphate of potash and carbonate of lead; the latter being
an insoluble precipitate may be separated from the solution of sulphate of
potash by decanting or drawing off. The sulphate of potash is now decomposed
by the addition of nitrate of soda, 12 lbs. of the latter being added for the
above quantities of sulphate of lead and pearlash or in that proportion, saltpetro
and sulphate of soda being the result, the two salts are then separated by
crystalization. The materials employed are thus all converted into merchant-
able products, viz., carbonate of lead (the white lead of commerce), nitrate of
potash (saltpetre), and sulphate of soda (Glauber salts).
The above process may be slightly varied without departing from the spirit
of my Invention as follows:-The nitrate of soda may be first decomposed by
the pearlash by boiling them together, the result being nitrate of potash and
carbonate of soda, the former to be separated by crystalization. The carbonato
of soda is then employed to decompose the sulphate of lead and the result as
before is carbonate of lead, nitrate of potash, and sulphate of soda, or the
nitrate of soda, the sulphate of lead and the pearlash may be mixed together,

page_text: whereupon a triple decomposition will take place. The carbonic acid of the
pearlash uniting with the lead, the nitric acid of the nitrate of soda with the
potash, and the sulphuric acid of the sulphate of lead combining with the soda
and forming, as before, carbonate of lead, nitrate of potash, and sulphate of
soda.
Having now set forth the nature of this Invention and explained the
manner of carrying the same into effect, I wish it to be understood that
under the above recited Letters Patent I claim,-
1st, the within described process of manufacturing sulphate of lead by
decomposing a solution of nitrate or acetate of. lead by sulphuric acid as set
forth, whereby the residuum is made available for the continuance of the
operation as specified.
2nd, I claim manufacturing carbonate of lead by decomposing sulphate of
lead with pearlash as set forth.
3rd, I claim manufacturing saltpetro and sulphate of soda of the residuum
of the above process combined with nitrato of soda as specified.
4th; I claim manufacturing carbonate of lead, saltpetre and sulphate of
soda out of sulphate of lead, pearlash, and nitrate of soda as described.
In witness whereof, I, the said William Edward Newton, have hercunto
set my hand and scal, the Twenty-eighth day of September, in the
year of our Lord One thousand eight hundred and fifty-nine.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
W. E. NEWTON. (L.S.)