New or Improved Process for the Production of Orystals and Crystalline Masses.
Year: 1892

page_text: Date of Application, 10th Feb., 1892
Complete Specification Left, 3rd Oct., 1892-Accepted, 12th Nov., 1892
PROVISIONAL SPECIFICATION.
New or Improved Process for the Production of Orystals and
Crystalline Masses.
I, JAMES MORRIS, D. Sc., of 5 Braidburn Crescent, Morningside in the City
of Edinburgh, Analytical Chemist, do hereby declare the nature of this invention
to be as follows:-
This invention consists of a new process or method of producing crystals or
crystalline masses mostly transparent and either coloured or colourless such crystals
or crystalline masses being composed chiefly or entirely of alumina.
The process consists fundamentally in igniting a very intimate mixture of
alumina and carbon to redness in iron retorts or other suitable vessels, a current of
carbonic acid gas being meanwhile led through the retorts or vessels. The carbon
is in whole or in part consumed and at least a portion of the alumina assumes the
crystallised or crystalline form.
The mixture of the alumina and carbon may suitably be produced by evaporating
a solution of chloride of aluminium in the presence of the carbon. Hydrochloric
acid escapes and the alumina is precipitated as such in the pores of the carbon.
The carbon used may be a mixture of wood charcoal and lamp black. The
evaporation is continued until a black plastic mass is left. This mass may then be
formed into balls or bricks and gently dried and the dried mass may then contain
the alumina and carbon in the proportion of one to one and a quarter. No
absolutely definite proportion is necessary. A mixture of charcoal and lamp black
is employed so that the balls or bricks may be porous and at the same time admit
of a most intimate mixture of the alumina with the carbon.
The balls or bricks may be of any suitable size from two up to eight or more
inches in diameter. Any mechanical arrangement such as small cages of wire may
be employed to make the balls or bricks hold better together. After being formed
they may be also exposed to a slow current of steam at a gentle heat which expels
a little more hydrochloric acid. They may be subsequently ignited in a current of
some neutral gas or alone in close vessels so as to free them from remaining water
either combined, or uncombined. This steaming and ignition of the balls or bricks
is preliminary to the main ignition in carbonic acid gas.
The
The carbonic acid gas may be obtained from any suitable source and should be
freed from any large amount of moisture or other injurious admixture.
presence of other, at least of neutral gases, in moderate proportion in the carbonic
acid gas may not be injurious. It is better, however, to use carbonic acid alone in
which case also the resulting carbonic oxide can more easily be re-converted to
carbonic acid and used in subsequent ignitions.
The ignition in carbonic acid gas may be continued from fifty to five hundred
hours or more.
Less than fifty hours may be sufficient in some cases. Crystals or
crystalline masses are formed before all the carbon is consumed.
The temperature employed may be a moderate red somewhat increased towards
the end of the operation.
The carbonic acid gas may be heated alone before being passed into the retorts
or vessels.
Gaseous fuel may be employed in heating. The retorts or vessels may be long
in proportion to their diameter for the better utilization of the carbonic acid.
The operation may be conducted at the pressure of the atmosphere. If artificial
pressure be employed all the apparatus must be of increased strength.
Compounds of cobalt of chromium or of similar substances may be added to the
original solution of chloride of aluminium or other salt of aluminium for the purpose

page_text: of imparting colours to the resulting crystals or crystalline masses. When it is
desired to produce colourless crystals or crystalline masses only it is not necessary
to add any compound of cobalt or of chromium or of any similar substance either
to the original solution of the salt of aluminium or at any stage of the process.
The compounds of cobalt, of chromium or of similar substances are added solely 5
or chiefly for their colour producing powers and do not play a primary part in the
process in so far as the latter is a method of producing alumina in the crystallised
or crystalline form.
Dated this Ninth day of February 1892.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.
COMPLETE SPECIFICATION.
New or Improved Process for the Production of Crystals and
.
Orystalline Masses,
I JAMES MORRIS D. Sc. late of 5 Braidburn Crescent Morningside in the City
of Edinburgh, now of 217 West George Street in the City of Glasgow Analytical
Chemist, 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 consists of a new process or method of producing crystals or
crystalline masses, mostly transparent, and either coloured or colourless, such crystals
or crystalline masses being composed chiefly or entirely of alumina.
The process consists fundamentally in igniting a very intimate mixture of
alumina and carbon in iron retorts or other suitable vessels, a current of carbonic
acid gas being meanwhile led through the retorts or vessels. The carbon is at least
in part consumed, and at least a portion of the alumina assumes the crystallised or
crystalline form.
The mixture of the alumina and carbon may be produced, among other methods,
by evaporating a moderately dilute solution of chloride of aluminium in the
presence of the carbon. Hydrochloric acid escapes, and the alumina is precipitated
as such in the pores and interstices of the carbon. If necessary, water may be
added, and the evaporation repeated, once or oftener.
The carbon used may suitably be a mixture of wood charcoal and lamp black, and
the carbon may have been previously purified by any suitable means. The evapora-
tion, or re-evaporation, is continued until a black, or grey, plastic mass is left. This
mass may then be formed into balls or bricks, and gently dried, and the dried mass
may then contain one part by weight of alumina to one and a quarter of carbon.
No definite proportion between the alumina and carbon is necessary. A mixture
of wood charcoal and lamp black is employed, so that the balls or bricks may be
porous, and at the same time admit of an intimate mixture of the alumina with
the carbon. No definite proportion of charcoal to lamp black is necessary. One
part by weight of charcoal to one and a half of lamp black may be used. The
charcoal should not be too finely ground.
The balls or bricks may be of any suitable size, from two up to eight or more
inches in diameter. When of large size they may have a few holes through them
for the better permeation by the carbonic acid gas. Any mechanical arrangement,
such as cages of nickel or other wire, may be employed to make the balls or bricks
hold better together.
After being formed, the balls or bricks may be exposed to a slow current of
steam, which may expel a little more hydrochloric acid. A gentle heat is applied
externally to the vessels in which this steaming is performed. They may be
subsequently ignited, either in the same or in other vessels, in a current of some
neutral gas, or they may be ignited alone in close vessels, the ignition being made

page_text: to free them from a large portion of the remaining water, combined as well as
uncombined. This steaming and ignition of the balls or bricks is preliminary to
the main ignition in carbonic acid gas. When the balls or bricks contain a
relatively large amount of carbon, the preliminary or separate ignition may be
omitted or at least shortened.
The subdivision of the mass into balls or bricks is mechanically convenient
but it does not form a fundamental part in the general principles of the process.
The carbonic acid gas may be obtained from any suitable source, and should
be freed from any large amount of moisture or other injurious admixture. The
presence of other, at least of neutral gases, in small or moderate proportion, in the
carbonic acid gas, may not be injurious. It is better, however, to use carbonic
acid alone, in which case also the resulting carbonic oxide can more easily be
re-converted into carbonic acid, and used in subsequent ignitions, or be otherwise
utilised.
The ignition of the mixture of alumina and carbon, in the form of balls or
bricks, or in any
other suitable form, may be continued, by preference continuously,
or at least without very frequent interruption, from fifty to five hundred hours
or more. Less than fifty hours may be sufficient in some cases. Crystals or
crystalline masses are formed before all the carbon is consumed. Mechanical
disturbance of the balls or bricks should be as far as possible avoided. By using
a proper mixture of roughly, and of rather finely powdered charcoal with the
lamp black, and by stopping the ignition at the proper point, the balls or bricks
assume a still more porous, or in some cases a honeycombed, structure which forms
an excellent bed or matrix for the alumina to crystallise in.
The average temperature employed in the main ignition may be a moderate red,
somewhat increased towards the end of the operation. No definite degree of
temperature is necessary. It is one of the advantages of my process that, under
the influence of the carbonic acid gas, the alumina assumes the crystallised or
crystalline form at temperatures of comparatively moderate ignition.
To promote equality and regularity of temperature the carbonic acid gas may
be heated alone before being passed into the vessels which contain the mixture of
alumina and carbon.
Gaseous fuel may be with advantage employed in heating; the retorts or vessels
may be long in proportion to their diameter for the better utilisation of the
carbonic acid, and the same carbonic acid may be made to pass through more
than one retort. The general arrangement of the retorts and furnaces may be
somewhat like that used in the production of ordinary coal-gas. Any suitable
mechanical arrangements may be used in connection with the process. Thus all
or any of the balls or bricks may be carried in or on sliding trays or cages placed
within the retorts or vessels.
The ignition may be conducted at the pressure of the atmosphere. If artificial
pressure be employed, the apparatus must be of increased strength.
The progress of the consumption of the carbon in the balls or bricks may be
gauged by testing a portion of the gases which escape from the retorts. It is
advisable to stop the ignition before the evolution of carbonic oxide has become
too weak.
Compounds of cobalt of chromium or of such substances as are employed in the
production of the finest kinds of coloured glass, may be added to the original
solution of chloride of aluminium, or other salt of aluminium for the purpose of
imparting colours to the resulting crystals or crystalline masses. Such colour-
giving compounds may also be added at any suitable stage of the process. Certain
compounds may also be added for the purpose of neutralising or correcting certain
colours. The compounds of cobalt, of chromium, or of other substances, are added
solely or chiefly for their colour-producing, colour-correcting, or colour-preventing
powers, and do not play a primary part in the process, in so far as the latter
is a method of producing alumina in the crystallised or crystalline form.
The purity of the crystals or crystalline masses will largely depend on the

page_text: purity of the materials used. A little of the carbon may, in some cases, become
incorporated or combined in the crystallised or crystalline alumina. Traces of
carbon, apart from any carbonic acid, have been found in beryls and emeralds.
Whatever may be the amount of carbon, or of other substances, in some individual
crystals the crystals or crystalline masses, obtained by my process, consist,
collectively, chiefly or entirely of alumina. In other words, if a considerable
number of the crystals or crystalline masses be tested or analysed at once,
they shall be found to consist, all reckoned together, chiefly or entirely of
alumina.
The balls or bricks, having been ignited in carbonic acid gas, may be subjected to
any suitable treatment, for the purpose of separating the crystals or crystalline
masses from the remaining uncrystallised alumina and unconsumed carbon.
The crystals, or crystalline masses, after having been produced substantially in
the manner already described, may be subsequently heated alone, or subjected to
any treatment, chemical or mechanical, for the purpose of modifying any of their
qualities. Such subsequent treatment of the crystals, after the main ignition
in carbonic acid gas, forms no primary part of the process, in so far as the
process is a method of producing alumina in the crystallised or crystalline
form.
I do not seek to explain why the alumina, under the influence of the carbonic
acid gas, assumes the crystallised or crystalline form. Sir James Hall found that
when the carbonic acid was kept in, limestone was converted on heating, into a
kind of marble. This experiment was repeated a long time afterwards, by
mineralogists in Germany and found to be, in the main, correct. The value of
the carbon in my process may be, to a large extent, mechanical.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :---
1. The production of crystals or crystalline masses such crystals or crystalline
masses being composed in most or in all cases, chiefly or entirely of alumina, by
igniting an intimate, or very intimate, mixture of alumina and carbon in a current
of carbonic acid gas.
2. The production of crystals or crystalline masses, composed, collectively,
chiefly or entirely of alumina, by the action of carbonic acid gas on an intimate,
or very intimate, mixture of alumina and carbon, the mixture being exposed,
during the greater part, or the whole, of the main process, to a temperature of
mod rate ignition.
Dind thi
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.