IMPROVEMENTS IN THE TREATMENT OF OBES OF LEAD FOR THE PURPOSE OF OBTAINING SALTS AND COLOURS OF THE SAME
Year: 1867

page_text: LETTERS PATENT to James Wright, Civil Engineer, and Thomas Cobley,
Metallurgist, both of 12, Copthall Court, Throgmorton Street, City of
London, for the Invention of "IMPROVEMENTS IN THE TREATMENT OF OBES
OF LEAD FOR THE PURPOSE OF OBTAINING SALTS AND COLOURS OF THE
SAME."
Sealed the 2nd August 1867, and dated the 6th February 1867.
PROVISIONAL SPECIFICATION left by the said James Wright and Thomas
Cobley at the Office of the Commissioners of Patents, with their Petition,
on the 6th February 1867.
We, JAMES WRIGHT, Civil Engineer, and THOMAS COBLEY, Metallurgist,
both of 12, Copthall Court, Throgmorton Street, City of London, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE TREAT-
MENT OF ORES OF LEAD FOR THE PURPOSE OF OBTAINING SALTS AND COLOURS OF THE
SAME," to be as follows, that is to say :-
Our process consists in first pulverising or reducing to a powder the ores of
lead to be treated; the powdered ore is then brought into a convenient
apparatus or receiver, and a quantity of chloride or perchloride of iron added
proportioned to the strength of the liquor employed and per-centage of lead
contained in the ore; the whole is boiled, being well stirred or agitated,

page_text: with steam or other convenient means, during which time chloride of lead
will be formed; this may be immediately drawn off and converted by double
decomposition or precipitation into any salt or colour of lead, or being allowed
to cool the chloride of lead from its great insolubility will deposit itself, may
then be collected and dried.
SPECIFICATION. in pursuance of the conditions of the Letters Patent, filed
by the said James Wright and Thomas Cobley in the Great Seal Patent
Office on the 6th August 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
WRIGHT, Civil Engineer, and THOMAS COBLEY, Metallurgist, both of 12,
Copthall Court, Throgmorton Street, City of London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the. Sixth. day of February, in the year of our Lord
One. thousand eight hundred and sixty-seven,, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said James Wright and Thomas Cobley, Her special licence that we, the said
James Wright and Thomas Cobley, our executors, administrators, and assigns,
or such others as we, the said James Wright and Thomas Cobley, our execu-
tors, 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." IMPROVEMENTS IN THE TREATMENT OF ORES OF LEAD FOR THE
PURPOSE OF OBTAINING SALTS AND COLOURS OF THE SAME," upon the condition
(amongst others) that we, the said James Wright and Thomas Cobley, our
executors or administrators, by an instrument in writing under our, 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 six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that we, the said James Wright and Thomas Cobley, 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:-

page_text: Having first pulverized or reduced to powder the ores of lead, we then mix
the same thoroughly with chloride or perchloride of iron, or a mixture of
hydrochloric acid and the said chloride or perchloride of iron, or the chloride
or perchloride of any other base capable of producing chloride of lead. This
may be done. by first mixing the proportionate quantity of liquid solvent with
the ore and allowing it to stand for a time and perfectly amalgamate. We
prefer to do this before we treat it with any heat as herein-after mentioned,
more especially when iron vessels are used, as the perchlorides would act upon
the iron and cause loss. After the materials have been thus properly mixed
we then act upon them with steam, or boil them in the usual way with the
necessary quantity of water to form a solution and until the lead has become
dissolved; the liquor in solution is then drawn off and allowed to cool, and
the chloride of lead thus formed is deposited. The supernatant liquor may
be used to form fresh solutions. In case silver is present we dissolve it after
each conversion into chloride of silver by means of chloride of sodium, ammonia,
and hyposulphides of the alkalies; should the chloride of lead be mixed with
iron we free it from the latter by washing with dilute bydrochloric acid, and
thus purified we convert it into white lead by means of magnesite, that is, native
carbonate of magnesia, in excess, the two being triturated together; the
chloride of magnesium resulting from the process to be carefully washed out;
the mass is then well dried. Other colors and salts of lead may be formed
by double decomposition or direct application of the acid, or it may be con-
verted into metallic lead by precipitation with zinc. Any insoluble salt of
lead formed may be converted into a pigment of lead by withdrawing a portion
of the acid with which it is combined by means of an alkali, alkaline earth, or
metal, thus rendering it into an oxysalt of lead. The acidulated waters used
in washing will be equally available for attacking fresh ores.
Having now described the nature of our Invention, and in what the same
consists, and the method and methods of carrying it into effect, we wish it
understood that what we claim as new and our Invention, and require secured
to us by the before in part recited Letters Patent is,-
First, the use of chlorides and perchlorides of iron for extracting lead from
the ores of lead by fractional deposition, that is, deposition by variation of
temperature, in the manner and after the way herewithin recited and set
forth.
Second, the use of bydrochloric acid for promoting and accelerating the
deposition and for purifying the salt of lead so formed, in the manner and as
herewithin recited.and set forth.

page_text: Third, the use of magnesite, that is, native carbonate of magnesia, in the
production of white lead by the method of trituration, in the manner and as
herewithin set forth.
In witness whereof the aforesaid James Wright and Thomas Cobley
have hereunto set their hands and seals, this Sixth day of August, One 5
thousand eight hundred and sixty-seven.
JAMES WRIGHT. (L.S.)
THOS. COBLEY.
(L.S.)