An Improved Process: of Making Oxide,
Year: 1895

page_text: 'Date of Application, 31st Dec:, 1895-Accepted, 1st Feb.,
1896:
Communicated from abroad by FHOMAS DENFIELD, 1922,
Avenue, Newark, Essex County, New Jersey, United States of America,
Manufacturer.]
An Improved Process: of Making Oxide, of Lead:
1, HENRY HARRIS LAKE, of the Firm, of Haseltine, Lake & Co. Patent
Algents, 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 :-.
My invention relates to an improved process for transforming; metallic lead into
an oxide of lead; the object of the invention being to provide a process whereby
the use of acids may be entirely omitted, and the time required to complete the
process of making such oxide materially shortened; the product at the same time
being perfectly free from the metallic lead.
With these and other ends in view, my invention. consists in first agitating in a
suitable vessel a quantity of lead in a fine, comminuted or granulated state,, in the
presence of air and water, whereby the same will be pulverized or powdered;.and
a portion thereof partially oxidized, and secondly, withdrawing said powdered, and
partially oxidized lead into a second vessel and there completing the oxidation by
agitation in the presence of water and an oxidizing gas.
The process further consists in certain novel features. hereinafter fully
described:
The accompanying drawing, shows one form of apparatus which may be used
for carrying out the process, but I would have it understood that I do not limit
my invention to this or any other particular form or construction of device,, as the
latter may be varied or changed in structure, in many ways to accomplish the same
results.
In practice, the pig or metallic lead is first treated in, any. desired manner;, to
reduce it to a fine, comminuted or granulated state, in which condition it is emptie |
or fed into the first tank A, constructed. of any suitable size or shape, and provided
with an outlet a to allow of a portion of its contents being withdrawn into a second
tank or vessel B, which may be constructed in substantially the same way as the
tank A.
'
Within the tank or vessel A is located a revolving device consisting of several
radial arms H, from which depend arms or ploughs h, said radial, arms or ploughs
being hollow. This revolving device is connected with a hollow shaft a¹, having
openings leading into the arms. H.
After a sufficient quantity of water and comminuted lead has been. fed into, th
vessel or tank A, the revolving shaft with its attached arms and ploughs is rapidly
revolved, a current of air at the same time being forced through the hollow shaft a
and into and throughout the mixture through the arms H and hollow ploughs,,
the effect being that the lead and water is kept in a state of violent agitation, the
purpose and effect of which is to cause the particles of lead to rub and grind against
each other, until they are reduced to a finely pulverized or powdered condition, the
introduction of the air into and throughout the mass causing a partial oxidation.of
the pulverized lead.

page_text: "
I
At a proper time the finer or powdered and partially oxidized lead is drawn
from the first into the second tank or vessel B in which is located a revolving
device C constructed, if desired, in the same way as that located in the tank A.
In withdrawing the mixture from the first into the second vessel, care should be
taken that no metallic lead follow; that is, no metallic lead other than that which
is very finely pulverized and capable of being oxidized in the second 'vessel. If the
apparatus be of such form or structure that there is likely to be some of the larger
or coarser particles drawn from the first vessel I advise that instead of withdrawing
the mixture: from the first. tank directly into the second, that such mixture be fed
from the first; vessel into a filter or separator (not shown) constructed in any
suitable or desired manner, in order that such coarser particles may be prevented
from entering the said second vessel. From such filter or separator, the coarser
particles may be returned to the first tank for further grinding or pulverizing,
while the finer or pulverized and partially oxidized lead may be fed from said
filter into the second vessel B. In the latter the partially oxidized lead, and
water is again violently agitated by the revolution of the hollow shaft and ploughs
contained therein, this agitation continuing for a suitable length of time, that is,
until the oxidation of the lead is completed, a current of air or an oxidizing gas, as
for instance, oxygen itself being introduced into and throughout the turbulent mass
through the hollow shaft, arms and ploughs; as, in the first, tank, this whirling or
agitation and simultaneous introduction of the oxidizing gas causing the complete
oxidation of every particle of metal.
וןדי.'
By carrying out this process' I have found in practice that a complete oxidation
of the metal takes place in a few hours, the product being superior to that which
has heretofore been produced by the "acid process," said product being completely
free from metallic lead and those acids which cause a crystallization of the
particles. thereby rendering it superior for the production of chrome, carbonate of
lead, and the like.
1.
****
I am aware that attempts have been made, to form an oxide of lead by grinding
or pulverizing it in the presence of air and water, but so far as I am aware these
attempts have proved: unsuccessful, in, that it has been impossible to free the
product from metallic lead. The defects in such prior processes I have learned by
experiment lay in the manner of introducing the air into the mass and also in the
fact that in these attempts it was endeavoured to grind or pulverize and oxidize in
a single vessel. The gist therefore of my present invention lies in the agitation of
the comminuted or granulated. .lead in the presence of water, air being
simultaneously introduced into and throughout the mass, for the purpose of
pulverizing or powdering and partially oxidizing the lead; secondly, again
agitating this partially oxidized lead and water and simultaneously introducing
into and throughout the mass, an oxidizing gas while in the second vessel.
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 making an oxide of lead consisting in first. agitating in. a
suitable vessel metallic lead in a comminuted form in the presence of water, and
simultaneously introducing air into and throughout the mass, for the purpose of
pulverizing and partially oxidizing the same, secondly, separating the pulverized
and partially oxidized lead from the coarser particles of metallic lead and again
subjecting it in a second vessel to further agitation in the presence of water
simultaneously with the introduction of an oxidizing gas into and throughout the
mass for completing the oxidation, substantially as described.
:
2. The process of making an oxide of lead consisting in first agitating in a
suitable vessel metallic lead in a comminuted form in the presence of air and water:
for the purpose of pulverizing and partially oxidizing the same; secondly, filtering
the pulverized and partially oxidized lead from the metallic lead, and thirdly,

page_text: subjecting said pulverized and partially oxidized lead to agitation in the presence
of water and an oxidizing gas.
Dated this 31st day of December 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.