An Improved Process for the Production of Iron Oxide for Use as a Pigment.
Year: 1893

page_text: Date of Application, 4th Sept., 1893
Complete Specification Left, 4th June, 1894-4ccepted, 25th Aug., 1894
PROVISIONAL SPECIFICATION.
An Improved Process for the Production of Iron Oxide for Use as a
Pigment.
1, CECIL HENRY MAXWELL LYTE of 60 Finborough Road, Redcliffe Square,
London, S.W. Esquire do hereby declare the nature of this invention to be as
follows:-
"
This invention relates to the production of iron oxide for use as a pigment.
According to my invention 1 mix caustic soda, caustic potash, or other suitable
soluble or sufficiently soluble base (or mixtures thereof) either in solution or in a
dry powdered state with iron ore, such for instance as burnt pyrites or the "purple
ore from the wet copper extraction process. This mixture, if moist, is dried and
it is then heated in a retort or otherwise to a low red heat, or to the temperature at
which the mixture becomes converted into a ferrite or ferrate of soda (if soda be
the base employed). This ferrite I then digest with heat in a sufficiency of water,
(boiling if requisite) until decomposition of the ferrite takes place with precipitation
of red oxide of iron and caustic soda in solution for use over again. Or I may
dissolve the ferrite in cold water, decant from any insoluble residue and heat the
clear solution, when precipitation of red oxide will take place. I do not limit
myself to any particular proportions of base to iron ore, but I find equal quantities
by weight of base and iron ore to answer well. The red oxide when washed and
dried may be again heated if desired to further improve the color and also ground
under edge runners to increase its density.
This process is also applicable to the residue of ferrite and iron ore resulting
from the processes described in former Applications for Letters Patent Nos. 13,654,
13,655, and 13,656 of 1893.
1 sdth 1002
C. H. MAXWELL LYTE,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.
COMPLETE SPECIFICATION.
An Improved Process for the Production of Iron Oxide for Use as a
Pigment.
I, CECIL HENRY MAXWELL LYTE, of 60, Finborough Road, Redcliffe Square,
London, S. W., Esquire, 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 the production of iron oxide for use as a pigment.
According to my invention I mix caustic soda, or caustic potash, (or a mixture
thereof) either in solution or in a dry powdered state, with crude iron oxide, such
for instance as 66
purple ore."
I do not limit myself to any particular proportions of base to iron ore, but I find
equal quantities by weight, of base and iron ore to answer well.
This mixture, if moist, is dried, and it is then heated, preferably in a retort or
muffle furnace, to the temperature (say a low red heat) at which the mixture
becomes converted into the so-called ferrite or ferrate of soda (if soda be the base
23

page_text: employed). This ferrite or ferrate I then digest in a sufficiency of water with
heat (boiling if requisite) until decomposition of the ferrite takes place with
precipitation of fine ferric oxide of bright color leaving caustic soda in solution
for use over again after concentration.
The residue from which the effluent of caustic solution is separated by decanta-
tion and filtration, consists of fine bright ferric oxide and some gangue. This is
washed to separate the ferric oxide by flotation and the ferric oxide may then be
heated by any of the usual methods to further improve the color, and ground under
edge runners to increase its density.
The gangue or residue from the washing of the ferric oxide may be added to the
next batch of "purple ore."
Or I
may dissolve the ferrite in cold water, decant the solution from any
insoluble and partly precipitated residue, and heat the clear solution until
precipitation of red oxide takes place, leaving caustic soda in solution which is
separated by decantation and filtration for use over again after concentration.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
The herein described process of producing ferric oxide for use as a pigment,
which process consists in heating a dry mixture of caustic soda or potash with iron
ore until the formation of an alkaline ferrite or ferrate, and then decomposing the
ferrite or ferrate by water and heat to precipitate the ferric oxide and obtain
caustic alkali, as specified.
Dated this 4th dow of Tunn
C. H. MAXWELL LYTE,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.