Year: 1886

page_text: 1, JOHN WARWICK of No. 108 Rye Hill in the City and County of Newcastle upon
Tyne, Lead Manufacturer, do hereby declare the nature of this invention to be as
follows:-
My invention of improvements in the manufacture of white lead consists, First in a
method of bringing the lead to be carbonated into a state of fine subdivision. Second
in exposing the finely divided lead at suitable temperature to the action of acetic acid,
carbonic acid, air and moisture in an apparatus arranged so as to expose from time to
time as may be desired fresh surfaces to the action of the gasses mentioned. Third, in
an arrangement of apparatus wherein the lead treated in the apparatus last described
is further treated so as to separate to some extent the finer particles of dry white lead
in a state of fine powder and Fourth in a method whereby separation is effected of the
remainder of the white lead from any particles of lead which may have remained
unconverted By my invention these operations are performed with the least possible
exposure of work people to the injurious effects arising in many other methods of
manufacture.
One part of my invention may be employed without another part but I prefer to use
all parts together.
For the subdivision of the lead referred to under the First head above described
I employ a rapidly revolving disc fixed upon a vertical shaft so that the disc revolves
in a horizontal plane.-I prefer to slightly raise the centre of the disc so as to make
its upper surface a very obtuse cone.-I cause melted lead to drop from any convenient
arrangement of apparatus upon this disc while it is rapidly rotating and I thereby
flatten and reduce the lead into a state of fine particles. I may collect the lead driven
from the wheel or disc in water, or may arrange a receiver round and below the disc
of such size as to obtain the requisite cooling by air.
The apparatus which I employ for the conversion of what is technically known as
blue lead into white lead referred to under read 2 consists by preference of a circular
chamber fitted with a central vertical shaft carrying upon it at regular intervals a
series of circular horizontal shelves, one over the other, extending to nearly the
circumference of the circular chamber before described. In the intervals between
each of the revolving shelves I place fixed shelves attached to the walls of the chamber
described and extending from the circumference of the chamber nearly to the revolving
shaft, by which arrangement it will be seen that the passage of any solid material or
gas through the chamber must be by a very circuitous route.-On the under surface
of the cover of the circular chamber and on the under surface of each revolving and
each fixed shelf I fix in symetrical order a series of scrapers or stirrers with flatened

page_text: blades set at such an angle as that at each revolution of the shelf or stirrer the angling
of the blades shall cause the material stirred slightly to move towards the centre or
towards the circumference of the shelf as the case may be, that is to say in such
direction as is required gradually to pass it through the circular chamber before
mentioned from top to bottom and over every shelf. The shape of the blades of these
scrapers or stirrers and the angle at which they are set I regulate so as to produce
adequate change of surface in the material stirred and adequate but not too great
movement of progression through the chamber-I rotate the central shaft at a very
slow rate continuously or at intervals. In the cover of this circular chamber I provide
a charging door or doors and by any convenient means I supply continuously or at
intervals a small charge of the subdivided blue lead already mentioned and at the
lower end of the chamber the gasses and vapours which are required for the conversion
of blue lead into white lead namely carbonic and acetic acid, air and vapour. I have
in the cover of the underside of the circular. chamber a discharging orifice and I
connect this discharging orifice to a spout or shoot whereby the matter discharged is
conveyed into a suitable receptacle or into waggons. In case it be desired to reduce
the weight on the central revolving shaft I may employ fixed shelves only and cause
the scrapers (which are then to be fixed to the shaft) to revolve.
With the material discharged from the circular chamber already described I charge
a revolving drum placed horizontally or slightly inclined at an angle to the horizon, in
which drum I place some spheres of granite; by the revolution of this drum the white
lead is more or less perfectly broken off from any unconverted particles of blue lead
which may have passed through the converting chamber and by the aid of the granite
spheres the converted white lead is more or less perfectly reduced to powder.—I make
the shaft on which this revolving drum is hung hollow in the greater part of its length
and within the drum I have it perforated so as that air may be blown into the interior
of the drum through one end of the shaft and taken from the interior of the drum at
the other end of the shaft carrying with it the finer particles of the white lead to be
deposited in settling receptacles provided for it from which it may be taken as an
extremely pure and fine dry white lead-With a view to prevent loss of impalpable
particles which might without very large settling receptacles be carried away-I cause
the same air to circulate through the drum over and over again.
After a part of the dry white lead has been extracted as described in the revolving
drum I may discharge the remainder into water and pass it under granite edge stones
so as more perfectly to separate the white from the blue lead which last I return with
fresh lead to the converting chamber before described-The process of grinding
whether in the drum or under the edge stone may of course be carried to any desired
degree and in fact in either of the arrangements the grinding might be wholly effected
but I prefer to take off in the drum the fine particles of the white lead as described
and to complete the process with the edge stones.-When the white lead is thus
perfectly separated from-the blue lead I grind it with oil under mill stones or rollers,
or work it up in any of the usual methods.
I may obtain the carbonic acid gas for use in the converting chamber by any
convenient means but I prefer to use for the purpose the fermentation of Spent
Tanners bark which I place in covered pits or chambers. After these are filled a short
time I pass through the mass of bark a regulated current of warm or cold air to
promote or control the fermentation and at the same time to force the gas formed into
the required position for acting upon the lead.-I keep the bark sufficiently moist and
warm by mixing vapour of water with the air passed through it.
I may employ the heat produced by the fermentation of the tanners bark to vaporize
the acetic acid required or I may employ as I prefer to employ for this purpose a
separate source of heat more easily regulated such as steam heat.-I regulate the heat
of the converting chamber by preference by means of coils of steam or hot water
pipes.

page_text: Improvements in the Manufacture of White Lead.
I, JOHN WARWICK of No. 108 Rye Hill, in the City and County of Newcastle-on-
Tyne Lead Manufacturer, do hereby declare the nature of my invention for IMPROVE-
MENTS IN THE MANUFACTURE OF WHITE LEAD, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
My Invention of improvements in the manufacture of white lead consists First in a
method of bringing the lead to be carbonated into a state of fine subdivision.-Second,
in exposing the finely divided lead at suitable temperature to the action of acetic acid,
carbonic acid air, and moisture in an apparatus arranged so as to expose from time to
time as may be desired fresh surfaces to the action of the gases mentioned. Third, in
an arrangement of apparatus wherein the lead treated in the apparatus last described
is further treated so as to separate to some extent the finer particles of dry white lead
in a state of fine powder, and Fourth in a method whereby separation is effected of the
remainder of the white lead from any particles of lead which may have remained
unconverted.
By my Invention theso operations are performed with the least possible exposure of
workpeople to the injurious effects arising in many other methods of manufacture.
One part of my invention may be employed without another part but I prefer to use
all parts together. For the subdivision of the lead referred to under the First head
above described I employ a rapidly revolving disc fixed upon a vertical shaft so that
the disc revolves in a horizontal plane.-I prefer to slightly raise the centre of the
disc so as to make its upper surface a very obtuse cone.-I cause melted lead to drop
from any convenient arrangement of apparatus upon this disc while it is rapidly
rotating and I thereby flatten and reduce the lead into a state of fine particles.-I may
collect the lead driven from the wheel or disc in water; or may arrange a receiver
round and below the disc of such size as to obtain the requisite cooling by air.-And
I may facilitate this cooling effect of the air by fitting the underside of the disc with
vanes like a fan and if desired casing these vanes within double walls so as to make it
in all respects like an ordinary fan. In Fig. 1. which represents a skeleton form of
apparatus adapted to the First part of my invention A. is a pot for melted lead, B is a
cullender through which the melted lead can escape in drops or small streams, C. is
the revolving disc onto which it falls, and D the shaft giving rotation to it the power
being applied from above-E. E. is a receiving chamber for the disintegrated lead
passing from the disc. The apparatus which I employ for the conversion of what is
technically known as blue lead into white lead referred to under head two, consists by
préference of a circular chamber fitted with a central vertical shaft carrying upon it at
regular intervals a series of circular horizontal shelves one over the other extending to
nearly the circumference of the circular chamber before described.-In the intervals
between each of the revolving shelves I place fixed shelves attached to the walls of the
chamber described and extending from the circumference of the chamber nearly to the

page_text: revolving shaft by which arrangement it will be seen that the passage of any solid
material or gas through the chamber must be by a very circuitous route.-On the
under surface of the cover of the circular chamber and on the under surface of each
revolving and each fixed shelf I fix in symetrical order a series of scrapers or stirrers
with flattened blades set at such an angle as that at, each revolution of the shelf or
stirrer, the angling of the blade shall cause the material stirred slightly to move
towards the centre or toward circumference of the shelf as the case may be that is to
say in such direction as is required gradually to pass it through the circular, chamber
before mentioned from top to bottom and over every shelf. The shape of the blades
of these scrapers or stirrers and the angle at which they are set I regulate so as to
produce adequate change of surface in the material stirred and adequate but not too
great movement of progression through the chamber. I rotate the central shaft at a
very slow rate continuously or at intervals. In the cover of this circular chamber
I provide a charging door or doors and by any convenient means I supply continuously
or at intervals a small charge of the subdivided blue lead already mentioned and at the
lower end of the chamber the gases and vapours which are required for the conversion
of blue lead into white lead namely carbonic and acetic acid air and vapour. I have
in the cover of the underside of the circular chamber a discharging orifice and I
connect this discharging orifice to a spout or shoot whereby the matter discharged is
conveyed into a suitable receptacle or into waggons or direct into the grinding
apparatus. In case it be desired to reduce the weight on the central revolving shaft
I may employ fixed shelves only and cause the scrapers (which are then to be fixed to
the shaft) to revolve.
In.Fig. 2 which represents a skeleton form of apparatus shewn in vertical section
adapted to the second part of my invention F. F. is the circular chamber, the central
vertical shaft is marked G., the horizontal shelves carried on it are marked I. The
circuitous route for the passage of solid matter through the chamber I have indicated
by a dotted arrow J. The stirrers or scrapers next mentioned are marked K. only
one scraper on each shelf is shown in the drawing to avoid confusion of lines but it
must be understood that there are more scrapers on each shelf and that the arrangement
is such as to cause the movements both of stirring and progression which I have
described. The charging door of the circular chamber is marked L.-The discharging
orifice of the circular chamber is shewn at M. The inlet pipe for gas is marked X
and the outlet pipe for gas is marked Y.
With the material discharged from the circular chamber already described, I charge
a revolving drum placed horizontally or slightly inclined at an angle to the horizon in
which drum I place some spheres of granite or other suitable crushers by the revolutions
of this drum the white lead is more or less perfectly broken off from any unconverted
particles of blue lead which may have passed through the converting chamber and by
the aid of the granite spheres the converted white lead is more or less perfectly reduced
to powder. I make, the shaft on which this revolving drum is hung, hollow in the
greater part of its length and within the drum I have it perforated so as that air may
be blown into the interior of the drum through one end of the shaft and taken from
the interior of the druin at the other end of the shaft carrying with it the finer particles
of the white lead to be deposited in settling receptacles provided for it, from which it
may be taken as an extremely pure and fine dry white lead.-With a view to prevent
loss of impalpable particles which might without very large settling receptacles be
carried away I cause the same air to circulate through the drum over and over again.
Fig. 3 is a skeleton forín of apparatus shewn in section illustrative of the third part
of my invention. N is the revolving drum, O, are the spheres of granite, P. is the
shaft, the perforations in which appear black in the section of the hollow shaft, the
passage of air into and out of the drum is shewn by dotted arrows. A receptacle
marked is shewn at the end of the drum in which the particles of white lead carried
out by the air may be deposited.-R, is a fan or blower arrangement by which the
circulation is maintained, it may be of any ordinary description.-I do not shew the
edge stones by which further separation is effected, because they are of any ordinary
description. After a part of the dry white lead has been extracted as described in-the

page_text: revolving drum I may discharge the remainder into water and pass it under granite
edge stones so as more perfectly to separate the white from the blue lead which last
I return with fresh lead to the converting chamber before described. The process of
grinding whether in the drum or under the edge stones may of course be carried to
any desired degree and in fact in either of these arrangements the grinding might be
wholly effected, but I prefer to take off in the drum the finer particles of the white
lead as described and to complete the process with the edge stones. I use edge stones
instead of horizontal mill stones so as not to grind any of the blue lead to such a state
of subdivision as that it would remain mixed with the white.-When the white lead is
thus perfectly separated from the blue lead I grind it with oil under mill stones or
rollers or work it up in any of the usual methods.
I may obtain the carbonic acid gas for use in the converting chambers by any
convenient means but I prefor to use for the purpose the fermentation of spent
Tanner's bark which I place in covered pits or chambers. After these are filled a
short time I pass through the mass of bark a regulated current of warm or cold air to
promote or control the fermentation and at the same time to force the gas formed into
the required position for acting upon the lead.-I keep the bark sufficiently moist and
warm by mixing vapour of water with the air passed through it or by occasionally
wetting the bark.
I may employ the heat produced by the fermentation of the Tanners bark to vaporize
the acetic acid required or I may employ as I prefer to employ for this purpose a
separate source of heat more easily regulated such as steam heat. I regulate the heat
of the converting chamber by preference by means of coils of steam or hot water
pipes not shewn in the drawings.
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:-
1st. The method of producing very finely divided particles of lead, substantially as
described.
2nd. The method of converting these particles or part of them into white lead,
substantially as described.
3rd. The mode of separation of very finely powdered white lead from white lead in
coarser particles substantially as described.
4th. The use of pits of bark through which currents of air or steam or both are
passed so as to give off carbonic acid substantially as described.
5th. The general arrangements and process of manufacture of white lead, all as
substantially described.
п
הזמשוחח
JAMESON
Agents for Applicant.