An Improved Method and Means of Producing Lead Oxide.
Year: 1895

page_text: Date of Application, 8th Nov., 1895
Complete Specification Left, 29th July, 1896-Accepted, 5th Sept., 1896
PROVISIONAL SPECIFICATION.
An Improved Method and Means of Producing Lead Oxide.
I, JAMES NOAD, of High Street East Ham, Essex, Engineer, do hereby
declare the nature of the said invention to be as follows
This invention relates to an improved method and means of producing lead oxide,
whereby the same is obtained in a floury condition free from metallic lead.
In carrying the invention into effect, I connect a lead melting chamber and a
lead oxide receiving chamber by a hood adapted to lead the lead oxide produced
in the melting chamber to the receiving chamber, wherein it deposits in a Houry
condition, as aforesaid.
To obtain the oxide in this condition, I strew the surface of the molten lead in
the melting chamber with sand, and continuously agitate the same and the layer of
oxide which forms on the molten lead by an arrangement of vanes or blades
adapted to keep the oxide in constant circulation on the molten lead.
Onto the layer or mass of the lead oxide, while thus being circulated, I direct a
supply of water, which may drip or be sprayed thereonto in suitable quantity, and
I also and simultaneously inject thereouto a jet or jets of air, the result of the joint
operation of the water and air and of the continuous circulation of the lead oxide
being the reduction of the oxide to a floury condition and the carrying over thereof
in such condition free from metallic lead from the melting chamber into the
receiving chamber, wherein it deposits, and from which it may be directly removed
or charged into casks or other containers.
The improved means comprise the combination, in co-operative organization with
said chambers and connecting hood, of means of automatically agitating and
circulating the layer of lead oxide, and of supplying or injecting the water and air
in respectively controllable quantities. The oxide circulator and the air blower
may advantageously be driven from a common shaft. I prefer also to combine
with the apparatus suitable means of keeping the surface of the bath of molten
lead at about the same level.
The receiving chamber is provided with means of relieving the pressure of the
current carrying over the, lead oxide, without permitting of the escape of the
latter.
Dated this Яih day of November 1895
I, JAMES NOAD, of High Street, East Ham, Essex, Engineer, 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:-
I
This invention relates to an improved process and means of converting metallic
lead into lead oxide, whereby, among other advantages, the time required to effect

page_text: the conversion is considerably shortened, and any required quantity can be more
speedily obtained than by any existing process of production, while the product is
obtained in an impalpable floury condition, and in a condition rendering it greatly
superior to lead oxide as hitherto produced for such uses in the arts and manu-
factures to which it is ordinarily applied.
To this end, the invention consists in effecting the production of the oxide by
subjecting lead, in a molten condition, in a suitable closed lead-melting tank, to the
combined influences of air injected thereonto, and of water (as such) which may
drip or be sprayed, or injected therconto, while the mass of liquid metal is kept in
violent agitation, and the surface thereof, upon which the air and water are
directed, is kept in turbulent motion, with the objects of causing a continuous
circulation of the molten metal particles and of any partly oxidized metal particles
floating thereon, and of bringing the same into the most intimate contact with the
elements of the air and water at a temperature which will dissociate such elements
and will facilitate the desired combination;-such process being effective in
causing the lead to be oxidized more expeditiously and more completely and less
expensively than is effected by any existing process of making lead oxide.
The accompanying drawings represent an arrangement of apparatus which may
be used with advantage in carrying out the improved process, but I do not restrict
myself to the exact construction or arrangement of the parts as illustrated.
Fig. 1, represents an elevation, partly in section; and Fig. 2, represents a plan.
a, represents a lead-melting tank, heated by a suitable furnace 6, and connected.
by a hood c, with a series of any required number of hoppers d, wherein the lead
oxide, produced in and carried over from the tank a, deposits in a floury condition,
as aforesaid.
The tank is fitted with a revolving agitator e, formed with several radial arms e 1,
adapted to plough over the bottom of the tank, and with vanes or blades e 2,
adapted to deflect the peripheral portions of the molten lead towards the centre,
and with stirrers e 3, adapted to agitate the mass of the molten metal and to break
up and to keep the surface thereof in turbulent motion. The shaft e 4, of the
agitator projects through the hood c, and is connected by gearing f, with a driving
shaft g, which is supported in brackets h, and is fitted with a driving pulley i,
adapted to be driven by any convenient motive power, and with a pulley j
The tank is also fitted with an air-tube k, fitted with jets k 1, serving to direct
jets of air onto different parts of or generally over the surface of the molten lead,
the air being supplied to the tube under pressure, by a blower m, driven from the
pulley j.
The tank is also fitted with pipes n, serving to direct fine streams or jets of
water onto different parts of or generally over the surface of the molten lead, the
water being supplied to the pipes n, by a common main o, from any convenient
reservoir, or otherwise in any convenient manner under any required pressure.
The piping supplying the air and water is fitted with cocks p, or like means of
regulating the supply.
The end hopper is connected to a condensing chamber q, of any required
capacity, into which any lead oxide which may be carried over by the current past
the hoppers will deposit, and in which any watery particles which may be carried
over will also condense. The chamber q, is covered by layers of fabric r, or may
be otherwise provided with means adapted to relieve the internal pressure due to
the operations effected within the tank a, and. to the current carrying over the
lead oxide, while preventing the escape of the latter; and is also fitted with a
tap s, for drawing off the condensed water, and formed with a doorway t, for
removing the deposited oxide.
In proceeding to produce the oxide; I find it of advantage, at the first, to strew
the surface of the molten lead in the tank a, with sand, and when the lead is
wholly molten, I set the agitator in rapid rotation so as to stir through the entire
mass of the fluid metal and to break up and keep its surface in turbulent motion,
and continue such agitation throughout the process; during which, the water is run

page_text: in fine streams or may be injected in a spraylike condition onto the turbulent
surface of the liquid metal and partly oxidized metal floating thereon by which it
is instantly dissociated into its elements, and explosively disperses the adjacent
metal particles and strips off the oxide coating from any partly oxidized metal
particles, while the air is also simultaneously injected onto such surface, where,
consequently, the molten lead particles and the partly oxidized and oxide-stripped
lead particles and the elements of the water and air are brought into most intimate
contact at a temperature which will facilitate the desired combination; the process
resulting in an extremely rapid and continuous production of lead oxide, which is
carried over in a cloudlike impalpable floury condition, and deposits into the
hoppers d, as it passes thereover, and from which it may be directly charged into
casks or other containers in a condition for immediate use in the arts or manu-
factures to which it is applicable, the process continuing, without interruption,
until the metal is wholly oxidized.
By the improved process, I am enabled, at will, to produce lead oxide of any
colour from a pale straw to a deep red as may be required according to the
intended purpose of the product, by simply regulating the temperature of the lead
bath, increasing the temperature the darker the colour is required.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. The process of producing lead oxide from metallic lead, consisting in ;-
subjecting lead, in a molten condition, in a suitable closed lead-melting tank, to the
combined influences of water (as such) and of air injected or fed thereonto, while
the mass of the metal and the surface thereof are kept in turbulent motion,
substantially as described.
2. The described means of producing lead oxide from metallic lead, the same
consisting in a lead-melting tank connected by a hood with a series of hoppers
wherein the lead oxide deposits and with a condenser, and fitted with an agitator
adapted to keep the mass and the surface of the molten metal in turbulent motion
and with means respectively serving to direct jets of water and of air onto the
molten metal, substantially as described.
Dated this 29th day of July 1896.
DAY, DAVIES & HUNT,
Chartered Patent Agents,
321, High Holborn, London, W.C., Agents for the Applicant.