CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF WHITE LEAD AND OTHER SALTS OF LEAD DIRECT FROM ORES CONTAINING CARBONATE OF LEAD
Year: 1861

page_text: LETTERS PATENT to John Arthur Phillips, of No. 12, Earl's Court,
Kensington, in the County of Middlesex, Civil Engineer, for the Inven-
tion of "CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF WHITE LEAD
AND OTHER SALTS OF LEAD DIRECT FROM ORES CONTAINING CARBONATE OF
LEAD."
Sealed 10th October 1861, in pursuance of an Order of the Lord Chancellor,
and dated the 15th March 1861.
on the 15th March 1861.
I, JOHN ARTHUR PHILLIPS, of No. 12, Earl's Court, Kensington, in the..
County of Middlesex, Civil Engineer, do hereby declare the nature of the
said Invention for "CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF WHITE LEAD
AND OTHER SALTS OF LEAD DIRECT FROM ORES CONTAINING CARBONATE OF LEAD,"
to be as follows:-
In order to obtain white lead from native carbonate of lead. I first grind the,
ore, and then expel the carbonic acid by roasting at a dull red heat; the ores
are then boiled with a strong solution of neutral acetate of lead, commonly
[Price 8d 1

page_text: called "
sugar of lead," and the solution after the ore or residue has been
allowed to settle, is syphoned off, and that portion of lead which it contains in
the form of neutral acetate is precipitated by a current of carbonic acid gas,
and the solution again employed to attack the same, or a fresh quantity of
roasted ore. By operating in this way it is easy to treat ores containing lime,
baryta, iron, and other minerals soluble in the ordinary acids. In order to
make acetate of lead, I either calcine the precipitate and redissolve it in acetic
acid, or add acetic acid to the basic solution obtained as before described.
Nitrate of lead and the other salts of lead are obtained by dissolving the pre-
cipitated carbonate of lead in nitric acid or some other acid with which it may
be desired to form a salt.
SPECIFICATION filed in pursuance of the conditions of the Letters Patent,
and of an Order of the Lord Chancellor, by the said John Arthur Phillips
in the Great Seal Patent Office on the 14th October 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
ARTHUR PHILLIPS, of No. 12, Earl's Court, Kensington, in the County of
Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of March, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Arthur Phillips, Her special licence that I, the said John
Arthur Phillips, my executors, administrators, and assigns, or such other
as I, the said John Arthur Phillips, 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 make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF WHITE LEAD AND OTHER SALTS
OF LEAD DIRECT FROM ORES CONTAINING CARBONATE OF LEAD," upon the condition
(amongst others) that I, the said John Arthur Phillips, my executors
or administrators, by an instrument in writing under my, or their, or one of
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

page_text: six calendar months.
Patent.
next and immediately after the date of the said Letters
NOW KNOW, YE, that I, the said John Arthur Phillips, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement :-
I take the ore of lead known as carbonate of lead, and having finely
pulverized it by suitable machinery, I subject it to a process of roasting in an
iron or clay retort furnished with agitators, and heated to a temperature not
exceeding seven hundred degrees Fahrenheit, by which means the carbonic
acid is expelled, and may be employed for the purpose of precipitating white-
lead from the subacetate in the next operation. For the purpose of facilitating
the elimination and utilization of the carbonic acid present in the ore, I employ
an exhausting apparatus, by means of which the gas evolved is forced through
subacetate of lead liquors for the purpose of forming white lead.
When clay retorts are used, I find the admixture of steam advantageous, as
tending to facilitate the evolution of carbonic acid, and to prevent the super-
oxidation of the lead. The ores when thus prepared are boiled with a strong
solution of acetate of lead, commonly called sugar of lead, in large wooden
tubs, provided with suitable stirrers. The liquors thus produced, after being
allowed to settle, are drawn off into proper receivers, where the white lead is
precipitated by means of a current of carbonic acid obtained from the roasting
of the crude ore, the combustion of charcoal, or any other known means.
The white lead when precipitated is collected and dried in the usual way.
The acetate of lead solution resulting from the precipitation of carbonate of
lead is employed for attacking a fresh quantity, according to a well-known
method of manufacturing white lead from litharge, employed in France and
elsewhere. In order to manufacture the salts of lead, such as the nitrate or
acetate, of a great degree of purity, the white lead prepared as above described
may be dissolved in suitable acids, and subsequently crystallized.
Having now described the nature of my said Invention, and in what manner
the same is to be performed, I wish it to be understood that what I claim
is, the roasting of carbonate of lead ores in close retorts, so as at the same
time to prevent the peroxidation of the metal, and also obtain a supply of
carbonic acid, and the direct treatment of the roasted ores thus prepared by
neutral acetate of lead, and subsequently by carbonic acid, by which means a
perfectly pure carbonate of lead is obtained from ores containing lime and iron,
which metals are invariably present in and injure the color of all white leads

page_text: prepared from these ores by the use of free acetic acid or an acid salt
of lead.
In witness whereof, I, the said John Arthur Phillips, have hereunto set
my hand and seal, this Eighth day of October, One thousand eight
hundred and sixty-one.
J, ARTHUR PHILLIPS. (L.S.)
Witness,
ALEX. PRINCE, Agent for Patents.
4, Trafalgar Square, Charing Cross.