IMPROVEMENTS IN. THE TREATMENT OF CERTAIN ORES OF LEAD. AND OBTAINING FROM THEM VALUABLE PRIMARY AND SECONDARY PRODUCTS
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by the said Frederick, William
Emerson at the Office of the Commissioners of Patents, with his
Petition, on the 17th February 1859.
I, FREDERICK WILLIAM EMERSON, of New Charlton, in the County of Kent,
Mining Engineer and Metallurgical Chemist, do hereby declare the naturė
of the Invention for "IMPROVEMENTS IN. THE TREATMENT OF CERTAIN ORES OF
LEAD. AND OBTAINING FROM THEM VALUABLE PRIMARY AND SECONDARY PRODUCTS,"
. :
to be as follows:-
My Invention consists in the treatment of certain ores of lead known as
mendipite or oxichloride of lead, phosphate of lead, and the arsenio-chlorides
and arsenio-phosphates of lead, native sulphates and carbonates of lead,
Price 8d.]

page_text: and all those ores of lead containing any combination of chlorine, phosphoric
acid, arsenious or arsenic acid, sulphuric acid, carbonic acid, or any mixtures
of the same, so as to produce therefrom oxide of lead for the preparation of
its various salts, as the acetate, nitrate, &c., and the various uses for which
litharge is now employed, red lead, or minium carbonate of lead,and metallic
or pig lead, and from the mendipite or oxichloride of lead, a very durable
A and anti-corrosive paint.
To produce oxide of lead from any of the above mentioned ores, Imix them,
after they have been well cleaned from the matrix or earthy gangue, with any
caustic alkali or caustic alkaline earths, or any mixture of the same, to whichI
add water, with or without the application of heat; and in some cases, with
the more refractory ores, I boil it under pressure of steam, and allow it to
remain until the chlorine, phosphoric acid, arsenious or arsenic acids,sulphuric
acid, carbonic acid, or any mixtures of same have been extracted; if in an
insoluble form, as the phosphates of lime, baryta, or magnesia, I separate it
from the resulting oxide of-lead with water,according to their specific gravities,
and apply the resulting phosphates to various useful purposes, as the pro-
duction of manures, and the manufacture of phosphorus and phosphoric acid;
if in a soluble form, I separate the resulting chloride, phosphate, or arsenite,
or arseniate from the oxide of lead by decantation, and where it has a com-
mercial value, as the chloride of barytes, or the phosphate of soda, I bring it
into a marketable shape by evaporation and crystallization. The resulting
lead oxide,after it is well washed, is then ready for mixing with acetic, nitric,
or other acids, for the preparation of the various salts of lead, or for other
useful purposes. In some cases I find it preferable to bring the ore into a
soluble state, by means of acids by preference, muriatic, and precipitate the
lead as an oxide by means of any of the caustic alkalies, or caustic alkaline
earths, or as a carbonate, by means of carbonic acid gas, or any alkaline or
alkaline earthy carbonate; and after thoroughly washing and drying the
resulting carbonate of lead oxide, it is then ready for use.
To convert the lead oxide, produced as before mentioned, into minium or
red lead, I roast or calcine it in a reverberatory furnace at a low heat, and
follow the same well known process as used for the conversion of litharge into
minium or red lead. For the production of metallic or pig lead, I mix the
oxide or the carbonate of lead, produced as aforesaid, with coal or coke dust,or
tar, or any convenient carbonaceous or reducing matter, and submit the same
to a melting heat in a reverbatory a retort, or any other convenient form of
reducing furnace. Or I take any of the before-mentioned ores of lead after

page_text: they have been well cleaned from the matrix or earthy gangue,and mix them
with caustic or carbonated alkali, caustic or carbonated alkaline earths, or
mixtures of the same and coal or coke dust, or tar, or any convenient carbon-
aceous or reducing matter, and submit the same to heat in a reverbatory
a retort, or any other convenient form of reducing furnace, and the resulting
metal, when melted, is run into any convenient moulds to form pigs.
Or, in the use of inendipite or oxichloride of lead ore, I sometimes find it
convenient to reduce it either with or without mixture of an alkali oralkaline
earth on mixtures of the same, by passing a stream of hydrogen gas or car-
buretted hydrogen gas over or through it in a retort furnace at a low red
heat, and afterwards urge the fire to a melting point.
To make a very durable anti-corrosive paint from the mendipite or oxi-
chloride of lead, I take the ore, after it has been very carefully cleaned from
the inatrix or earthy gangue, and reduce it to an impalpable powder, or as
nearly impalpable as possible, by grinding in water or otherwise; and after
thoroughly drying it is ready to be mixed and ground with oil, turpentine,"
varnish, or other suitable vehicle, and used as a paint.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick William Emerson in the Great Seal Patent
Office on the 17th August 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
WILLIAM EMERSON, of New Charlton, in the County of Kent, Mining
Engineer and Metallurgical Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Pateut, bearing date the Seventeenth day of February, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Frederick William Emerson, Her special licence that I, the
said Frederick William Emerson, my executors, administrators, and assigns,
or such others as I, the said Frederick William Emerson, 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

page_text: Man, an Invention for "IMPROVEMENTS IN THE TREATMENT OF CERTAIN ORES OF
LEAD, AND OBTAINING FROM THEM VALUABLE PRIMARY AND SECONDARY PRODUCTS,"
upon the condition (amongst others) that I, the said Frederick William
Emerson, 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 six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said Frederick William Emerson, 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 thereof, that is to say: -
My Invention consists in the treatment of certain ores of lead known as
mendipite or oxichloride of lead, phosphate of lead, and the arsenio-chlorides
and arsenio-phosphates of lead, native sulphates, and carbouates of lead, and
all those ores of lead containing any combination of chlorine, phosphoric
acid, arsenious or arsenic acid, carbonic acid, sulphuric acid, or any mixtures
of the same, so as to produce therefrom oxide of lead for the preparation
of its various salts as the acetate, nitrate, &c., and the various uses for which
litharge is now employed, red lead, or minium, carbonate of lead, and
metallic or pig lead, and from the mendipite or oxichloride of lead, a very
durable and anti-corrosive paint.
I now proceed to specify the methods I prefer to be used to carry my
Invention into effect; at the same time the details of such methods are
capable of variation.
In treating any of the ores of lead containing chlorine, phosphoric acid,
arsenious or arsenic acids, sulphuric acid, carbonic acid, or any mixtute of the
same for the production of lead oxide, I take a fair sample from the bulk of
ore to be operated upon, and make a correct chemical analysis of the same,
for the determination of the quantity of acid or mixture of acids in combi-
nation with the base; I then place the bulk of ore to be operated upon in any
convenient vessel of wood, slate, or other suitable substance, and add to it an
equivalent quantity, as shewn by the previous analysis (I prefer to use a slight
excess), of any caustic alkali, or caustic alkaline earths, or any mixture of the
same (by preference caustic soda, but that would depend upon the commercial
value according to the state of the markets for the secondary products, and
other circumstances), to which I add water, either hot or cold; by preference,

page_text: I pass into the liquor a jet of steam, and keep it up to a boiling
point, until the chlorine, phosphoric acid, arsenious or arsenic acids, sulphuric
acid, carbonic acid, orany mixtures of the same have been extracted. In some
cases with the more refractory ores, I prefer to conduct the operation in an iron
boiler under a pressure of steam of several atmospheres, say three or more.
When the acid has been extracted from its combination with the lead, if it
should be in an insoluble form, as the phosphates of lime, baryta.or magnesia,
I separate it from the resulting lead oxide, with water, according to their
specific gravities, and apply the resulting phosphates to various useful pur-
poses, as the production of manures, and the manufacture of phosphorous
or phosphoric acid by any of the methods well-known to manufacturing
chemists. If in a soluble form, I separate the resulting chloride, phosphate,
or arsenite or arseniate from the lead oxide by decantation, and where it
has a commercial value, as the chloride of barytes, or the phosphate of soda,
I bring it into a marketable shape by evaporation and crystallization. The
resulting lead oxide, after it is well washed, is then ready for mixing with
acetic, nitric, or other acids for the preparation of the various salts of lead
according to well-known processes and for other useful purposes. In some
cases, I prefer to bring the ore into a soluble state by digesting it with acid (by
preference muriatic acid) in any convenient vessel, with or without heat (by
preference with heat applied by a jet of steam conducted into the vessel) and
precipitate the lead from the solution as an oxide by means of any of the
caustic alkalies or caustic alkaline earths or as a carbonate, by means of car-
bonicacid gas or any alkaline oralkaline earthy carbonate, and after thoroughly
washing the resulting carbonate of lead oxide, it is then ready for use.
To convert the lead oxide produced, as before mentioned, into minium or
red lead I roast or calcine it in a reverberatory furnace, at a low red heat,
and follow the same well-known process as used for the conversion of litharge
iuto ininium or red lead. For the production of metallic or pig lead from the
lead oxide or carbonate of lead produced, as aforesaid, I mix the same with
its chemical equivalent of any carbonaceous or reducing matter, such as coal
or coke dust, or tar, and submit the same to a melting heat in a reverberatory
or retort or any other convenient form of reducing furnace. To produce
metallic or pig lead from any of the before-mentioned ores, aftor they are well
cleaned from the matrix or earthy gangue, I mix the same with an equivalent
(as determined by analysis as aforesaid) of caustic or carbonated alkali,
caustic or carbonated alkaline earths, or mixtures of the same (by preference,
either soda ash or soda lime) and from one-fourth to one-fifth of the weight of

page_text: lead ore, of coal, or coke dust, or tar, or any convenient carbonaceous or
reducing matter, and submit the same to a melting heat in a reverberatory
retort or other convenient form of reducing furnace. In some cases, I find
it must convenient (especially for operating upon very large quantities of the
ore) to treat it in the blast furnace, which I prefer of the following form and
dimensions, namely, an inverted cone, flattened at the apex, eight feet in
height from the hearth stone (which should be on a slight incline with the tap
hole at the lowest part, to facilitate the running of the charge and cleaning of
the interior) three feet in diameter at the bottom, and six feet in diameter at
the mouth or tunnel head, the tuyere or blast hole about three feet from the
bottom or hearth stone, and a tap-hole for slag or scoria, about six inches
above the tuyere hole on the opposite side to the same. I prefer to deliver the
blast into the furnace compressed by any well-known mechanical means,
through a two-inch tuyere at about two pounds pressure on the square inch.
For fuel I prefer to use coke, and when the furnace has come to its heat, 1
charge it alternately with coke (proferring to keep the charge of ore always
covered by the charge of coke at the surface or tunnel head) and ore by
preference mixed with its equivalent of soda ash or soda lime, and made into
convenient sized balls or lumps, with coke dust and tar, or other convenient
form of carbonaceous or reducing matter.
As a general rule and under convenient circumstances, I prefer to reduce
any of the before-mentioned ores, by treating them in a retort furnace,
especially the combinations of chlorine, arsenic, and phosphorous, the retort
may be made of iron, fire clay, or other convenient substance of any con-
venient size, according to the scale of operations. For this method, I intro-
duce the ore into the retort, either with or without mixture of an equivalent
as aforesaid, of alkali or alkaline earth, or mixtures of the saine, and the
carbonaceous or reducing matter, as aforesaid, and pass over or through the
'same a stream of hydrogen or carburetted hydrogen gas (by preference peator
common coal gas,
well purified from sulphur) at a low red and increasing heat
until the lead ore is reduced to the metallic state; I then urge the fire to the
melting point until it is all or nearly all run out. The retort should be set on
a slight incline to facilitate the running out of the metal. The molten metal
produced by any of the before-mentioned methods, is then run into moulds to
form pigs. To make a very durable anti-corrosive paint from the mendipite
.or oxichloride of lead; I take the ore after it has been very carefully cleaned
from the matrix or earthy gangue, and reduce it to an impalpable powder or
.as nearly impalpable as possible, by grinding in water or otherwise, and

page_text: after thoroughly drying, it is ready to be mixed and ground with oil,
turpentine, varnish, or other suitable vehicle and used as a paint.
Having now described the nature of my Invention, and the manner
of performing the same, I would have it understood, that what I claim, are
the methods herein-described of treating ores of lead containing chlorine,
phosphoric acid, carbonic acid, arsenious or arsenic acid, sulphuric acid, or
any mixtures of the same.
In witness whereof, I, the said Frederick William Emerson, have here-
unto set my hand and seal, this Fifteenth day of August, in the year
of our Lord One thousand eight hundred and fifty-nine.
F. W. EMERSON. (L.s.)