Improvements in the Process of Treating Oxidized or Corroded Lead, and in Apparatus therefor.
Year: 1892

page_text: Date of Application, 8th Nov., 1892-Accepted, 21st Jan., 1893
COMPLETE SPECIFICATION.
[Communicated from abroad by RICHARD WILLIAM FRANK ABBÉ, of
No. 631, Lorimer Street, City of Brooklyn, State of New York, United
States of America, Engineer.]
Improvements in the Process of Treating Oxidized or Corroded Lead,
and in Apparatus therefor.
I, HENRY HARRIS LAKE of the firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings in the County of Middlesex do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to a process of treating oxidized or corroded lead by what
I term a "dry process" in contradistinction to the old process in which the product
is separated from the blue lead in vats of water, entailing a subsequent drying of
the product and consequently a loss of time and labor.
In the old process the bar lead is oxidized or corroded in the usual manner and
is then conveyed to the rollers. After passing through the rollers the material is
conveyed to a screen in which the flattened blue lead is separated from the oxidized
or corroded lead. The rolling process is objectionable as it makes too compact a
mass, so that the screening separates a portion only of the litharge or lead while a
great portion of it is pressed into and remains in the blue lead and comes out as
tailings, requiring the process to be repeated. Also in the old process the litharge
or lead is taken from the screen to burr-stones or chasers and ground, then to vats
of water where the blue lead still retained in the screening sinks and the litharge
or lead is floated off into other vats. Of course the product must then go through
a'drying process.
The old process is objectionable on account of the time and labor consumed in
the operation, and I obviate the objections by producing the product by a very
much simplified process.
In my process the bar lead is first oxidized or corroded, and after being
sufficiently oxidized or corroded it is fed, by an elevator or otherwise, to a
pulverizing apparatus.
I prefer the pulverizer to be of the class having a revolving cylinder lined
with a suitable material to prevent contact of the material to be ground with
contaminating substances, such as iron. This cylinder is tightly closed and is
partially filled with loose pulverizers, either pebbles, balls or rollers, and revolved
at a slow speed. By this means the oxidized or corroded lead is liberated by
abrasion of the loose pulverizers from the "blue lead," by which I mean the lead
which is not oxidized or corroded, and the blue lead flattened by the pebbles, balls,
or rollers.
After discharging out of the cylinder the material is conveyed by any suitable
means, at once to a bolter in which the blue lead is easily separated from the
oxidized or corroded lead. It is easily separated in the bolter because the blue
lead is in a flat state and the oxidized or corroded lead is reduced to a fine powder
which is forced through the bolter. The material forced through the bolter is the
desired product. The material or tailings remaining in the bolter can be again
oxidized if desired.
Having described 'the process I will now describe an apparatus by which it may
be carried out. Reference being had to the accompanying drawing in which--
Figure 1 is a diagramatic view, partly in section, of such an apparatus.
Figure 2 is an enlarged detail in section.
Figure 3 shower for the nulverizaŕ

page_text: A. designates a rotary pulverizing cylinder arranged within a suitable closed
casing A', and having. an opening A³ through which the material to be pulverized
may be fed from the hopper A.
This cylinder is preferably lined with a suitable material a, such as porcelain, to
prevent contact of the material' with the iron of the cylinder, and is partially filled
with pulverizers a, in the form of balls, pebbles or the like.
The shaft of the cylinder A. projects outside the casing A' and is provided with
a gear wheel a² meshing with a gear wheel a³ on the shaft of the band pulley a',
which is driven by a band from the main shaft a', and consequently rotates the
cylinder.
When material to be pulverized is within the cylinder A it is tightly closed
by means of the close cover B. When the material is sufficiently pulverized the
cover B is removed and the grate cover B' is put in its place. As the cylinder is
again rotated the pulverized material will fall through the openings of the cover B¹
to, the bottom of the casing A' from which it will be discharged by a worm
conveyor B2 into a bin B³.
From the bin B³ the material will be carried by a bucket elevator B and
discharged into a chute B³ and thence into a rotary bolter C arranged within a
closed casing C¹.
It will be seen that both the elevator B4 and the bolter C are driven from the
main shaft a³.
The bolter is tapered from end to end, the larger end being over the chute C²,
and is open at its ends.
The bolter has a body portion c of wire sieve material and an outer covering of
bolting cloth c¹.
The rotation of the bolter C forces the fine product through the bolting cloth
into the hopper c² from which it falls into the closed bin c³.
The tailings work down to the larger end of the bolter and discharge into a
receiver through the chute C².
As a considerable amount of heat is generated in the cylinder A by the abrasion
of the loose pulverizers I provide means for the escape of heated air. As herein
shown this means consists of a valve D having a seat D¹ in a casting which forms
a seat for the cover B. This valve D has a screw threaded stem d which engages
in a fixed nut d', and an angular portion of this stem passes loosely through a bevel
gear D2 which meshes with a segmental bevel gear D³ on a shaft D¹ having
bearings in arms d² extending from the cylinder A. On the outer end of the
shaft D is an arm d³ extended at substantially right angles to the shaft, which,
when the cylinder A is in its upward position, will strike against a fixed cam
surface d⭑. This cam surface will turn the arm d³ and consequently rotate the
parts to raise the valves D. After the arm d³ shall have passed the cam surface d*,.
à spring, d, secured at one end to an arm d² and at the other end to the shaft Di
will turn the parts in the opposite direction and force the valve back to its seat.
In discharging the pulverized material from the cylinder A into the casing A¹
a small amount of the dust will float in said casing which it is necessary to remove.
As a means therefor I provide a pipe E leading from the upper part of the
casing A¹ to a chamber E. A rotary suction fan E in the chamber E¹ serves to
draw the dust and a small amount of the lead into the chamber E¹. The material
thus drawn in will strike against radial wings e in the chamber E¹ which will cause
the heavy particles to fall to the lower part of the chamber E¹ and the dust will
escape through a pipe e¹.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent I declare that what I claim is :
1. The process of obtaining the powdered product of oxidized or corroded lead,
consisting in abrading a mass of such lead by rolling contact with loose bodies other
than the lead itself until the powder is wholly detached from the blue lead and in

page_text: subsequently transferring all of the blue lead and powder to a bolter and bolting
the powder from the mass of blue lead, substantially as specified.
2. In a machine for treating oxidized or corroded lead the combination of a
rotary cylinder, having pulverizers therein, means for automatically allowing the
escape of air from said cylinder, and a bolter, substantially as specified.
3. In a machine for treating oxidized or corroded lead the combination with a
rotary pulverizing cylinder and a casing within which the same rotates, of a suction
device for drawing dust from said casing, substantially as specified.
4. In a machine for treating oxidized or corroded lead the combination with a
rotary pulverizer cylinder of a valve carried by said pulverizer cylinder, a gear
having a loose connection with the stem of said valve, a gear meshing with the first
named gear, and means for rotating said gears, substantially as specified."
Dated this 8th day of November 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.