Improvements in or connected with the Production of Lead Oxide and in Means or Apparatus Employed therein
Year: 1898

page_text: Reprinted as amended in accordance with the decision of the Supervising
Examiner acting for the Comptroller-General, dated the 9th day of August,
1910.
Improvements in or connected with the Production of Lead Oxide and
in Means or Apparatus Employed therein.
We, MATTHEWS' LANCASHIRE, CHESHIRE AND NORTH WALES DISTRICT WHITE
LEAD COMPANY, LIMITED, Manufacturers of White Lead, SAMUEL POPE, Manager
of the said Company, and GEORGE VINCENT BARTON, Secretary of the said Com-
pany, all of Old Quay, Runcorn, in the County of Cheshire, do hereby declare
the nature of this invention to be as follows:
The invention relates to improvements in or connected with the production
of lead oxide and in means or apparatus employed therein and the primary
object thereof is to obtain lead oxide in a more rapid and economical manner
than heretofore.
In carrying the invention into effect a covered pot or vessel formed of iron
or other suitable material is employed provided with a gas or other furnace
capable of efficiently heating the lead to be treated and a quantity of lead is
from time to time introduced into the pot and by the furnace maintained in the
required fluid state.
In a suitable position at the side of the pot and above the molten lead is
provided an outlet arranged either radially or tangentially and extending either
radially or tangentially from the wall of the pot at the rear side of said outlet
towards or if desired beyond the centre of the pot is arranged a suitably shaped
vertical baffle plate or curtain which is preferably adjustable and extends
nearly to the bottom of the pot or to such a position as will enable it to scrape
the surface of the lead when the latter is in motion as hereinafter described.
At or near the bottom of the pot and beneath the baffle plate or curtain is
provided a horizontal paddle or stirrer which is fixed upon a vertical shaft
receiving rotary motion at a regulated speed from any suitable source of power
and this stirrer dashes the molten lead against the baffle plate, or curtain in
front of the outlet.
Adjacent to the surface of the molten lead is arranged a pipe which is
perforated at intervals and formed with an open but flattened end and extends
horizontally from the rear side of the baffle plate or curtain in a circular form
partly around the pot and terminates at some distance from but with its open
flattened end pointing towards the baffle plate or curtain and this pipe is
supplied with combined air and steam under pressure for example by the aid
of a vena contracta from any suitable source.

page_text: The perforations in the pipe are arranged at such an angle as to cause the
issuing steam and air to impinge upon the molten lead and at the same time
travel in the direction of the outlet from the pot.
Or if desired separate pipes for the air and steam might be employed, or
several sets of pipes might be employed.
In order to produce lead oxide by the means herein before described the fur-
nace is started and the pot is charged with a suitable quantity of lead which is
maintained in a molten condition by the furnace; the stirrer is then set in
motion at a suitable speed of rotation and the supply of air and steam under
pressure is admitted by the perforated pipe and impinges upon the surface of
the molten lead by which means said surface becomes coated with a film of
oxide which is carried round with the lead until its progress is arrested by
the baffle plate or curtain.
The lead and oxide are brought into contact with the baffle plate or curtain
with some degree of force and their impact therewith causes the oxide to rise
in a cloud which is controlled by the baffle plate or curtain and deflected
towards the outlet through which it is carried by the current of air and steam
to suitable receiving or collecting chambers where the oxide is deposited in
the form of an impalpable powder of great purity.
The baffle plate or curtain scrapes the surface of the lead and frees it from
oxide leaving that part of the surface beyond the baffle plate or curtain clean
for the current of air and steam to act upon.
In the same manner mixed rough litharge may be converted into fine lead
oxide thus avoiding the operations of grinding and levigation to free the lead
oxide from the metallic lead usually intermixed therewith when lead oxide is
produced by the old method of cupellation.
For this purpose a charge of the mixed rough litharge is introduced into the
pot and floats upon the surface of the molten lead; the apparatus is put in
action, the oxide is caught by the curtain and under the combined influence
of the stirrer, heat, steam and air and the curtain or baffle plate, is reduced to
a fine state of division and carried into the receiving chambers, where it is
collected in a state of fine powder ready for use.
Any metallic lead in the rough litharge is liquefied by the heat maintained
in the not or vessel and becomes oxidized and by these means the whole of the
rough litharge is recovered as a fine powder of lead oxide.
Dated this 9th day of August, 1898.
WHITE & WOODINGTON,
Rooms 221 to 225, Birkbeck Bank Chambers,
Southampton Buildings, London,
Agents.
Improvements in or connected with the Production of Lead Oxide and
in Means or Apparatus Employed therein.
0.
We, MATTHEWS' LANCASHIRE, CHESHIRE AND NORTH WALES DISTRICT WHITE
LEAD COMPANY, LIMITED, Manufacturers of White Lead, SAMUEL POPE, Manager
of the said Company, and GEORGE VINCENT BARTON, Secretary of the said Com-
pany, all of Old Quay, Runcorn, in the County of Cheshire, 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:-
The invention relates to improvements in or connected with the production

page_text: of lead oxide and in means or apparatus employed therein and the primary
object thereof is to obtain lead oxide in a more rapid and economical manner
than heretofore..
In carrying the invention into effect a covered pot or vessel formed of iron
or other suitable material is employed provided with a gas or other furnace
capable of efficiently heating the lead to be treated and a quantity of lead is
from time to time introduced into the pot and by the furnace maintained in the
required fluid state.
În a suitable position at the side of the pot and above the molten lead is
provided an outlet arranged either radially or tangentially and extending either
radially or tangentially from the wall of the pot at the rear side of said outlet
towards or if desired beyond the centre of the pot is arranged a suitably shaped
vertical baffle plate or curtain which may if desired be adjustable and extends
downward to a suitable position as hereinafter described.
At or near the bottom of the pot and beneath the baffle plate or curtain is
provided a horizontal paddle or stirrer which is fixed upon a vertical shaft
receiving rotary motion at a regulated speed from any suitable source of power
and this stirrer creates a kind of wave in the molten lead the crest of which
comes against the baffle plate or curtain in front of the outlet.
Adjacent to the surface of the molten lead is arranged a pipe which is
formed with an open end and extends horizontally from the rear side of the
baffle plate or curtain in a circular form partly around the pot and terminates
at some distance from but with its open end pointing towards the baffle plate
or curtain and this pipe is supplied with combined air and steam under pres-
sure for example by the aid of a vena contracta from any suitable source.
Or if desired separate pipes for the air and steam' might be employed, or
several sets of pipes might be employed.
In order to produce lead oxide by the means herein before described the fur-
nace is started and the pot is charged with a suitable quantity of lead which is
maintained in a molten condition by the furnace; the stirrer is then set in.
motion at a suitable speed of rotation and the supply of air and steam under
pressure is admitted by the pipe and impinges upon the surface of
the molten lead by which means said surface becomes coated with a film of
oxide which is carried round with the lead until its progress is arrested by
the baffle plate or curtain.
The crest of the wave of lead and oxide is brought into contact with the
baffle plate or curtain with some degree of force and its impact therewith causes
the oxide to rise in a cloud which is controlled by the baffle plate or curtain
and deflected towards the outlet through which it is carried by the current of
air and steam to suitable receiving or collecting chambers where the oxide is
deposited in the form of an impalpable powder of great purity.
In the same manner mixed rough litharge may be converted into fine lead
oxide thus avoiding the operations of grinding and levigation to free the lead
oxide from the metallic lead usually intermixed therewith when lead oxide is
produced by the old method of cupellation.
For this purpose a charge of the mixed rough litharge is introduced into the
pot and floats upon the surface of the molten lead; the apparatus is put in
action, the oxide caught by the curtain and under the combined influence
of the stirrer, heat, steam and air and the curtain or baffle plate; is reduced to
a fine state of division and carried into the receiving chambers, where it is
collected in a state of fine powder ready for use.
Any metallic lead in the rough litharge is liquefied by the heat maintained
in the pot or vessel and becomes oxidized and by these means the whole of the
rough litharge is recovered as a fine powder of lead oxide.
And in order that the said invention may be more clearly understood and
readily carried into effect we will proceed aided by the accompanying draw-
ings more fully to describe the same.

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1 is a vertical longitudinal section representing a plant for carry-
ing the said invention into effect.
Figure 2 is a plan thereof with part removed.
Figure 3 is a vertical transverse section taken on the line 1-1 of Figure 1.
Figure 4 is a front end elevation of the apparatus with the pot removed.
Figure 5 is a rear end elevation thereof partly in section.
Figure 6 is a front elevation of the covered pot or vessel separately.
Figure 7 is a plan thereof.
Figure 8 is a side elevation thereof partly in section.
Figure 9 is a rear elevation thereof.
Figure 10 is a horizontal section taken on the line 2-2 of Figure 8.
Figure 11 is a vertical transverse section showing the upper part of the pot
separately.
In the several figures in which like parts are indicated by similar letters of
reference, Figures 4 and 5 are drawn to an increased scale with respect to
Figures 1 to 3 whilst Figures 6 to 11 are drawn to a still further increased scale.
Referring to the drawings a represents a closed pot or vessel, d represents a
furnace for heating the same, e represents a collecting chamber for the oxide
and f g h represents an apparatus for trapping the lighter particles of oxide
and preventing their escaping into the outer air.
The pot or vessel a is formed of iron or other suitable material capable of
withstanding the heat to which it is subjected and the furnace d which may be
a coal gas or other suitable furnace must be capable of efficiently heating the
lead to be treated and which is contained in the pot a.
The pot a is furnished at its rear with two openings a¹ a² closed by means
of suitable covers, one of said openings namely that a serving as a manhole
and the other a² serving as a feed opening through which a quantity of fused
lead is from time to time introduced into the pot a said lead being afterwards
maintained by the furnace in the required fluid state.
At the rear side of the pot a and above the molten lead is provided an outlet a³
to which is connected a shoot at which communicates with the collecting
chamber e hereinafter more fully referred to.
Extending tangentially from the wall of the pot a at the rear side of the
outlet a to the centre of the pot a or it might be beyond is a suitably shaped
baffle plate or curtain a which terminates in an apertured boss as formed on
the upper part of the pot a and this curtain or baffle plate a extends down-
ward to a suitable position as hereinafter described.
At or near the bottom of the pot a and beneath the baffle plate or curtain a³
is provided a horizontal paddle or stirrer b which is fixed upon a vertical
shaft passing through the apertured boss a6 which forms a bearing to the
shaft and at its upper end said shaft is mounted in a bearing 63 supported by a
frame carried by the upper part of the pot a.
The vertical shaft band consequently the paddle or stirrer b receive rotary
motion at a regulated speed through a bevelled toothed wheel b fixed upon the
vertical shaft which engages a bevelled pinion 66 fixed upon a horizontal
shaft 65 at its ends mounted in bearings 67 carried by the frame 2 and furnished
with fast and loose pulleys 68 by means of which the shaft b¹ and paddle b may
be driven from any suitable source of power.
The paddle or stirrer 6 which revolves in the direction of the arrow Figure 10.
or there might be several stirrers as will be readily understood, carries round
with it the molten metallic lead which forms a kind of wave the crest of which
dashes against the baffle plate or curtain a5 said action taking place in front
of the outlet a³.
Above the surface of the molten lead is arranged a pipe c which is formed
with an open but downwardly curved end c¹ and this pipe extends horizontally

page_text: from the rear side of the baffle plate or curtain a³ in a circular or curved form
so that its open end points in the direction in which the molten lead or the
surface thereof is required to travel and this pipe c is supplied with combined
air and steam under pressure, for example by the aid of a vena contracta_c³
placed in the pipe c and into which enters a pipe supplied with steam under
pressure from any suitable source.
The pipe e is open to the atmosphere or is similarly supplied with air and
the blast of combined air and steam issuing from the mouth of the pipe c
is caused to impinge upon the surface of the molten lead and at the same time.
travel in the direction of the outlet a³ from the pot a.
It will be understood that instead of the arrangement shown in the drawings
any other suitable contrivance or contrivances might be employed for convey-
ing a blast of air and steam either combined or not onto the surface of the metal.
In order to produce lead oxide by the means herein before described the
furnace is started and the pot a is charged through the feed opening a² with
a suitable quantity of fused metallic lead which is maintained in a molten
condition by the furnace d.
The paddle or stirrer 6 is then set in motion at a suitable speed of rotation
through the pulleys 68 herein before referred to and the supply of air and steam
under pressure is admitted by the pipe e and impinges upon the surface of the
molten lead by which means said surface becomes coated with a film of oxide
which is carried round by the lead which assumes a wave like form its crest
coming against the baffle plate or curtain a³.
The lead and oxide are brought into contact with the baffle plate or curtain a
with some degree of force and their impact therewith causes the oxide to rise
in a cloud which is controlled or directed by the baffle plate or curtain a³ and
deflected towards the outlet a³ through which and through the shoot a it is
carried by the blast or currrent of air and steam into the receiving or collecting
chambers or apparatus e f g h hereinafter more fully referred to where the
oxide is finally deposited in the form of an impalpable powder of great purity.
The cloud of oxide passing through the shoot at is carried by the blast into
the first of a series of collecting chambers c which communicate with one
another by openings at the upper part thereof, and these chambers are at
their lowest point furnished with openings e² closed by doors by means of
which the deposited oxide may be removed from time to time.
The oxide entering the chambers c through the shoot at is deposited in the
collecting chambers according to its specific gravity as is well understood, and
the lighter particles are carried through the end opening e¹ into a trunk or
chamber which at its lower end opens into a tub g containing water and near
to its lower end by means of a lateral connection f communicates with a
vertical pipe h the lower end of which is immersed in the water of the tub g
and which at its upper end opens into the lower end of a barrel h¹ furnished
with a number of inclined and overhanging shelves or baffle plates h² onto
which water is allowed to flow in regulated quantities from a cock ¹ supplied
by a pipe connected with any convenient reservoir of water.
By means of this device the lighter particles of oxide which do not become
deposited in the chambers e pass into the trunk f and the heavier particles are
carried by the blast into the water of the tub g whilst the lighter particles
pass by the connection fl into the pipe h where on entering the barrel h they
encounter and require to pass through the circuitous passage between the.
shelves and which are covered by a film of water which flows from shelf to
shelf and the escaping blast of steam and air to some extent atomises the water
so that it is virtually impossible for any portion of the oxide to escape into
the open air and the process is thus rendered comparatively harmless.
The oxide deposited in the tub g is removed and submitted to the usual final
processes to render it marketable, or for the production of white lead.
In the same manner mixed rough litharge may be converted into fine lead

page_text: '
oxide thus avoiding the operations of grinding and levigation to free the lead
oxide from the metallic lead usually intermixed therewith when lead oxide is
produced by the old method of cupellation."
For this purpose a charge of the rough litharge is introduced into the pot a
and floats upon the surface of the molten lead the apparatus is put into action
the oxide is caught by the curtain a5 and under the combined influence of the
stirrer bair and steam and curtain a5 is reduced to a fine state of division and
carried into the collecting apparatus where it is recovered in a state of fine
powder ready for use.
Any metallic lead in the rough litharge is liquefied by the heat maintained in
the pot or vessel a and becomes oxidized and by these means the whole of the
rough litharge is recovered as a fine powder of lead oxide.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, we, declare that
what we claim is:-
1. A process for the production of lead oxide consisting in maintaining a
quantity of metallic lead in a fused state in a closed pot or vessel, stirring
said lead, directing a blast of air and steam upon the surface of the fused lead
so as to oxidize the same and by means of said blast carrying the oxide thus
produced through an opening in the wall of the vessel into suitable collecting
or grading chambers substantially as herein shown and described.
2A--process--for--the--production--of--lead--oxide--consisting-in-maintaining--a
of-air-and-steam-upon-the-surface-of-the-fused-lead-se-as-to--oxidize--the-same--and
by-means-of-said-blast-carrying-the-oxide-thus-produced-through-an-opening-in-the
wall-of-the-vessel--into--suitable-collecting--or-grading-chambers-substantially-as
quantity-of-metallie-lead-in-a-fused-state-in-a-closed-pot-or-vessel, directing-a-blast
herein-shown-and-described:
2. A process for the production of lead oxide consisting in maintaining a
quantity of metallic lead in a fused state in a closed pot or vessel provided with
an outlet to a collecting chamber stirring said fused lead in one direction,
directing a blast of air and steam upon the surface of the fused lead so as to
oxidize the same and by means of a baffle plate or curtain arresting the moving
film of oxide in front of said outlet so that it will be caught by the blast and
carried through the outlet into the collecting chambers substantially as herein
shown and described.
3. 4. A process for the production of lead oxide from rough litharge con-
sisting in maintaining a quantity of metallic lead in a fused state in a closed
pot or vessel provided with an outlet to a collecting chamber stirring said
fused lead introducing a charge of rough litharge thereon directing a blast of
air and steam upon the rough litharge on the surface of the fused lead and by
means of said blast carrying the oxide thus produced through the outlet into
the collecting chambers substantially as herein shown and described.
4. An apparatus for the production of lead oxide comprising a closed pot
or vessel adapted to contain a charge of lead, means for heating said pot a
collecting chamber, an outlet from the pot, à connection between the outlet and
the collecting chamber, means for directing an oxidizing blast onto the surface
of the fused lead a paddle or stirrer within the pot, means for rotating the
paddle, and a baffle plate or curtain projecting laterally from the rear side of
the outlet towards the centre of the pot and extending downwardly into a
position to catch the film of oxide substantially as herein shown and described
and for the purpose stated.
0
5. 6. An apparatus for the production, of lead oxide comprising a closed pot
or vessel adapted to contain a charge of lead, means for heating said pot, means
for oxidizing the surface of the lead, a collecting chamber an outlet from the
pot to the collecting chamber, means for keeping the lead in motion, a baffle
plate or curtain projecting laterally from the rear side of the outlet towards the

page_text: centre of the pot and extending downwardly into position to catch the film of
oxide and means for carrying the oxide through the outlet into the collecting
chamber substantially as herein shown and described and for the purpose stated.
Dated this Oth day of Mov 1800
WHITE & WOODINGTON,
Rooms 221-225, Birkbeck Bank Chambers,
Southampton Buildings, London,
Agents.