Process and Apparatus for the Manufacture of Ultramarine.
Year: 1890

page_text: Date of Application, 17th Nov., 1890
Complete Specification Left, 4th Aug., 1891-Accepted, 26th Sept., 1891
PROVISIONAL SPECIFICATION.
[Communicated from abroad by the firm JULIUS CURTIUS, of Duisburg, in the
German Empire, Manufacturers.]
Process and Apparatus for the Manufacture of Ultramarine.
1, OLIVER IMRAY of No. 28, Southampton Buildings, Chancery Lane, in the
County of Middlesex, Fellow of the Institute of Patent Agents, do hereby declare
the nature of this invention to be as follows:-
In the preparation of sulphate- and soda-ultramarine the process has heretofore
been, that the intimate mixture of the raw materials was heated in porous
refractory vessels of clay fire clay &c. The gaseous, volatile and liquid products
evolved from the heated mixture passed through the porous walls of the vessel and
in mixing with the combustion gases, escaped into the atmosphere and became
obnoxious to the surrounding neighbourhood.
The use of metal, offering impermeable walls, for the said vessels, was not
practicable on account of the sulphur contained in the charge, which in forming
sulphur compounds with the metal, destroyed the vessels, and these could
therefore only be made of refractory materials that are bad conductors of
heat.
These bad conductors of heat soon becaine cracked, as with the ordinary
heating process employed, which is not continuous, the vessels were at one time
heated to redness, and at another time were cooled down to atmospheric
temperature. In thus cooling, the ultramarine is subject at the cracks to a
strong oxidation by the air which has access thereto, and thus becomes grey
and useless. A. uniform crude ultramarine can never be obtained in such refractory
vessels and bad conductors of heat, but the crude pigments obtained therein must
always be carefully sorted, yielding larger or smaller quantities of waste, and of
inferior blue.
The above defects are avoided according to the present invention by the use
of metal, in particular cast iron vessels, which are for this purpose coated
internally with a thin layer of such refractory materials which are not only not
attacked by the incandescent charge and by the gases or liquid or volatile
compounds evolved therefrom, but which also preserve the materials from contact
with the outer metal vessel. The thickness of the vessels can be considerably
decreased and consequently the heat conducting power thereof considerably
increased, so that in consequence of the uniform heating of the charge, under
complete exclusion of the outer air, a perfectly uniform crude ultramarine is
obtained with comparatively small expenditure of fuel.
In addition, as compared with the process carried out with porous heating
vessels crucibles, muffles, retorts &c., the great advantage is gained that owing to
the impermeable nature of the vessels, all contact and mixing of the gases, liquids,
or vapours, evolved from the charge with the combustion gases is avoided, and it
is possible to entirely retain such escaping gases &c. by conducting them into
lead chambers, condensing columus or suitable absorbing vessels, as also to directly
regain a portion of the sulphur used, and thus any contamination of the atmosphere
by means of the escaping gases is avoided. As material for the inner lining of the
metal vessels, any refractory substances that resist the action of acids, alkalies
and in particular sulphur compounds, such as sodium sulphide, sodium hypo-
sulphite, &c. may be used.
For this purpose is employed by preference a dense coating of so called
refractory cement for lining the retorts or other vessels of cast iron or other
metal

page_text: This lining can be renewed in the simplest manner on its gradual wearing
away,
by painting over the defective places with a mixture of the cement with
syrup, water, or other liquid binding material.
The accompanying drawing shews a construction of retort furnace for carrying
out the above described process.
Fig. 1 shows a longitudinal section and Fig. 2 a sectional plan; the number of
retorts is of course optional. The retorts a, b, c, provided with the above mentioned
lining are walled into the brickwork at the one end, projecting beyond the
same; they are supported at various points of the length by bridge pieces of
refractory material, and can be put into communication with the atmosphere at the
other end through a tube m, which can be hermetically closed. and d are short
tubes, capable of being closed, which put the interior of the retorts a b c in com-
munication with the cooling and oxidizing or collecting chambers p and 9 extending
transversely beneath and which communicate by a piper, with the vessels & serving
for the absorption of the gaseous products.
The porous slab fin the retorts prevents the charge contained in the back part
of the retort becoming loosened and breaking down during the heating. In order
to obtain a perfectly uniform heating of the retorts, the combustion gases passing
through the chamber are drawn off through two opposite openings into the
flues & and pass thence into the main flue F.
This apparatus is used as follows:-The intimate mixture of the finely ground
raw materials is introduced into the right hand rear part of the retorts; the
porous, slab is then placed in front, the cover t is closed airtight and the connection
with the chamber p is closed.
On heating, the gaseous, volatile and liquid products escape through the porous
slab and the tube d into the chamber a from which the gaseous and volatile parts
thereof pass directly into the absorption vessels or into a lead chamber without
mixing with the combustion gases, while the liquid products, in particular the
distilled sulphur remain in g. When the reaction is completed, the green crude
ultramarine contained in the retort can be very rapidly oxidized into blue ultra-
inarine on opening the cover and the tube m, by drawing in air through m; or
the opening d can be closed and the green crude ultramarine be raked into the
chamber pon opening the covert and removing the slab f, so as to be oxidized in
this chamber.
The retorts are then immediately filled again with raw materials, and the
operation is repeated.
Dated this 17th day of November 1800.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Process and Apparatus for the Manufacture of Ultramarine.
I, OLIVER IMRAY. of No. 28, Southampton Buildings, Chancery Lane, in the
County of Middlesex, Fellow of the Institute of Patent Agents, 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:-
In the preparation of sulphate- and soda-ultramarine the process has heretofore
been, that the intimate mixture of the raw materials was heated in porous refractory
vessels of clay, fire clay &c. The gaseous, volatile and liquid products evolved
from the heated mixture passed through the porous walls of the vessel and in
mixing with the combustion gases, escaped into the atmosphere and became
obnoxious to the surrounding neighbourhood.
The use of metal, offering impermeable walls, for the said vessels was not
practicable on account of the sulphur contained in the charge, which in forming

page_text: sulphur compounds with the metal, destroyed the vessels, and these could therefore
only be made of refractory materials that are bad conductors of heat.
These bad conductors of heat so 'n became cracked, as with the ordinary heating
process employed, which is not continuous, the vessels were at one time heated to
redness, and at another time were cooled down to atmospheric temperature. In
thus cooling, the ultramarine is subject at the cracks to a strong oxidation by the
air which has access thereto, and thus becomes grey and useless. A. uniform crude
ultramarine can never be obtained in such refractory vessels and bad conductors of
heat, but the crude pigments obtained therein must always be carefully sorted,
yielding larger or smaller quantities of waste, and of inferior blue.
The above defects are avoided according to the present invention, by the use of
metal, in particular cast iron vessels which are for this purpose coated internally
with a thin layer of such refractory materials which are not only not attacked
by the incandescent charge and by the gases or liquid or volatile compounds
evolved therefrom, but which also preserve the materials from contact with the
outer metal vessel. The thickness of the vessels can be considerably decreased and
consequently the heat conducting power thereof considerably increased so that in
consequence of the uniform heating of the charge under complete exclusion of
the outer air, a perfectly uniform crude ultramarine is obtained with comparatively
small expenditure of fuel.
In addition as compared with the process carried out with porous heating vessels
crucibles, muffles, retorts &c., the great advantage is gained that owing to the
impermeable nature of the vessels, all contact and mixing of the gases, liquids or
vapours evolved from the charge with the combustion gases is avoided, and it is
possible to entirely retain such escaping gases &c. by conducting them into lead
chambers, condensing columns or suitable absorbing vessels, as also to directly
regain a portion of the sulphur used, and thus any contamination of the atmosphere
by means of the escaping gases is avoided. As material for the inner lining of
the metal vessels, any refractory substances that resist the action of acids alkalies
and in particular sulphur compounds, such as sodium sulphide, sodium hypo-
sulphite &c. may be used.
For this purpose is employed by preference a dense coating of so called refractory
cement for lining the retorts or other vessels of cast iron or other metal. Or
silicates of alumina,. coke, graphite &c. may be used, the particles being if
necessary cemented together by means of carbonisable cementitious substances,
such as dextrine, syrup, and the like.
This lining can be renewed in the simplest manner on its gradual wearing away,
by painting over the defective places with a mixture of the cement with syrup,
water, or other liquid binding material.
The drawing accompanying my Provisional Specification shews a construction
of retort furnace for carrying out the above described process.
Fig. 1. shews a-longitudinal-section, and Fig. 2. a sectional plan; the number
of retorts is of course optional. The retorts a, b, c provided with the above
mentioned lining are walled into the brickwork at the one end, projecting beyond
the same; they are supported at various points of the length by bridge pieces of
refractory material, and can be put into communication with the atmosphere at the
other end through a tube m, which can be hermetically closed. and d are short
tubes, capable of being closed, which put the interior of the retorts a be in
communication with the cooling and oxidising or collecting chambers p and q
extending transversely beneath and which communicate by a pipe r with the
vessels serving for the absorption of the gaseous products.
The porous slab in the retorts prevents the charge contained in the back part
of the retort becoming loosened and breaking down during the heating. In order
to obtain a perfectly uniform heating of the retorts, the combustion gases passing
through the chamber 9 are drawn off through two opposite openings into the
flues ss and pass thence into the main flue F.
This apparatus is used as follows: The intimate mixture of the finely ground

page_text: raw materials is introduced into the right hand rear part of the retorts; the porous
slab is then placed in front, the cover is closed airtight and the connection with
the chamber p is closed.
On heating, the gaseous, volatile and liquid products escape through the porous
slab and the tube into the chamberg from which the gaseous and volatile parts
thereof pass directly into the absorption vessels or into a lead chamber without
mixing with the combustion gases, while che liquid products, in particular the
distilled sulphur remain in g. When the reaction is completed, the green crude
ultramarine contained in the retort can be very rapidly oxidized into blue ultramarine
on opening the covert and the tube m, by drawing in air through m; or the opening d
can be closed and the green crude ultramarine be raked into the chamber pon
opening the cover and removing the slab f, so as to be oxidised in this chamber.
The retorts are then immediately filled again with raw materials and the
operation is repeated.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is -
:-
1. Process for the production of ultramarine wherein the intimate mixture of the
reduced raw materials is honted in a metal vessel which is internally coated with
an impermeable lining of refractory cement, or of silicates of aluminia, coke,
graphite &c. (the latter being by preference cemented together by means of
carbonisable cementitious substances, such as dextrine, syrup &c.) in order thereby
to prevent the gascous volatile and liquid products passing away from the metal
vessel, from mixing with the furnace gases, and to enable such products to be
regained; while at the same time a uniform heating of the charge and a corre-
sponding uniform product is obtained with a minimum expenditure of fuel, owing
to the good heat conducting properties of the vessel.
2. A retort furnace for carrying out the process referred to in the preceding
claim consisting of a number of metal retorts lined internally with a dense refractory
lining capable of resisting chemical action, and communicating with a common
cooling and oxidizing chamber p, as also with absorption vessels h or with a lead
chamber, the said retorts being if necessary provided with an air supply tube m
that can be closed, in order to effect the oxidation of the ultramarine either in the
retorts or in the cooling chamber, while the escaping gases and liquid products
which usually mix with the furnace gases are collected, so that the heating process
can be carried on uninterruptedly, substantially as described.
Dated this 4th day of August 1891.
ABEL & IMRAY,
Agents for the Applicant.