AN IMPROVED PROCESS FOR THE MANUFACTURE OF WHITE LEAD
Year: 1879

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention
of "AN IMPROVED PROCESS FOR THE MANUFACTURE OF WHITE LEAD." A
communication from abroad by George T. Lewis, of Philadelphia, Pennsylvania,
and Eayre O. Bartlett, of Pemberton, New Jersey, both in the United States
Sealed the 30th March 1880, and dated the 1st December 1879.
PROVISIONAL SPECIFICATION loft by the said William Robert Lake at
the Office of the Commissioners of Patents on the 1st December 1879.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
"AN IMPROVED PROCESS FOR THE MANUFACTURE
Southampton Buildings, London.
OF WHITE LEAD." [A communication from abroad by George T. Lewis, of Phila-
delphia, Pennsylvania, and Eayre O. Bartlett, of Pemberton, New Jersey, both in
the United States of America.]
When white lead pigment is manufactured from Galena or other lead ores in the
raw state, or even in the roasted state, by subjecting them to the joint action of
heat and air, either with or without reducing means, according to the quality of the
lead ores used, the fumes are discolored by particles of carbon or sulphuret of lead,
or both, when they are caught in bags of textile fabric, and are unfit in this state
for use as a white pigment. The fumes which are produced by this action of heat
and air on Galena or other lead ore are cooled and then collected in bags, and
according to the present Invention I expose the so collected products to the joint
action of heat and air, to destroy or burn out all the particles of carbon, sulphuret
of lead, or both, by either throwing the said fumes on a bright clean anthracite
or coke fire, with blast from the sides or from below, or by throwing them
over such fires or into a cupola furnace, or by throwing or blowing them into a
generator gas flame, or through externally heated retorts, and then in either case
I collect the escaping fumes from the furnace or retort in bags or screening
chambers.
The best process to be adopted depends upon the kind of fuel in the locality
where the fumes are refined, and also upon the purity of the lead fumes. If they

page_text: contain iron, clay, or the like it is best to throw them into a coal fire, but if they
are pure the one process is about as effective as the other, and the degree of purity
of the fuel decides the kind of heating apparatus to be used.
There being such great difference in the purity of fuels, and this irregularity not
allowing of uniform results, I prefer to use a furnace in which the flame and heat
therefrom are produced by burning gaseous fuel with air, which is forced into the
furnace with the aforementioned fumes, which have been collected in a previous
process.
The undermentioned apparatus may be advantageously used in the improved
process above described, that is to say, a furnace is provided in which gas is used
as fuel. The fumes are fed into a blower from a hopper, and being thoroughly
mixed with air in the blower they are forced into a chamber, and then through a
series of tuyeres. At the same time gas from a generator or producer is admitted
by a flue and is burned by the incoming blast from the tuyeres. The volatile fumes
produced in the furnace pass through it and out of another flue, and are collected in
bags or screening chambers.
By using gas fuel it is readily seen to be both easily and fully burned and clean
to handle, producing a fine white pigment.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Scal Patent Office on the
31st May 1880.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED PROCESS FOR THE MANUFACTURE
OF WHITE LEAD." A communication from abroad by George T. Lewis, of Phila-
delphia, Pennsylvania, and Eayre O. Bartlett, of Pemberton, New Jersey, both in
the United States of America.
When white lead pigment is manufactured from Galena or other lead ores in the
raw state, or even in the roasted state, by subjecting them to the joint action of
heat and air, either with or without reducing ineans, according to the quality of the
lead ores used, the fumes are discolored by particles of carbon or sulphuret of lead,
or both, when they are caught in bags of textile fabric, and are unfit when in this
state for use as a white pigment.
The fumes which are produced by this action of heat and air on Galena or other
lead ore are cooled and then collected in bags, and according to the present Inven-
tion I expose the so collected products to the joint action of heat and air, to destroy
or burn out all the particles of carbon or sulphuret of lead, or both, by either
throwing the said fumes on a bright clean anthracite or coke fire, with a blast from
the sides or from below, or by throwing them over such fires or into a cupola
furnace, or by throwing or blowing them into a generator gas flame, or through
externally heated retorts. I then in either case collect the escaping fumes from the
furnace or retort in bags or screening chambers.
The best process to be adopted depends upon the kind of fuel in the locality
where the fumes are refined, and also upon the purity of the lead fumes. If they
contain iron, clay, or the like it is best to throw them into a coal fire, but if they
are pure one process is about as effective as the other, and the degree of purity of
the fuel decides the kind of heating apparatus to be used.
There being such great difference in the purity of fuels, and this irregularity not
allowing of uniform results, I prefer to use a furnace in which the flame and heat
therefrom are produced by burning gaseous fuel with air, which is forced into the
furnace with the aforesaid fumes which have been collected in a previous process.
The accompanying Drawing represents a furnace which may be advantageously
employed for the purposes of this Invention when gas is used as fuel.
Q represents a blower into which the fumes are fed from the hopper R. The
fumes being thoroughly mixed with air in this blower are forced into a chamber S,
and then through a series of tuyeres T. At the same time gas from a generator or
producer is admitted by the flue V, and is burned by the incoining blast from the
tuyeres T; the volatile fumes produced in the furnace U pass through it and out of
the flue X, and are collected in bags or screening chambers. By using gas fuel,
which is easily and fully burned and clean to handle, a fine white pigment is
produced.
Having thus fully described the said Invention, as communicated to me by my
foreign correspondents, and the manner of performing the same, I wish it understood
that I claim,
The manufacture of white lead pigment from the waste lead fumes of furnaces
used for producing lead from Galena or other native lead ore, by blowing such fumes
into a generator flame, or over or into a clean fire in a second furnace, where they
are thoroughly burned with a blast of air, substantially as above set forth.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Thirty-first day of May, in the year of our Lord One
thousand eight hundred and eighty.
111