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

page_text: Date of Application, 15th Oct., 1892
Complete Specification Left, 24th June, 1893-Accepted, 9th Sept., 1893
PROVISIONAL SPECIFICATION.
New or Improved Process for the Production of Crystals or
Crystalline Masses.
I, JAMES MORRIS, D.Sc., of 217 West George Street in the City of Glasgow,
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 chemically akin to the crystals or stones found
in nature and which are generally known as spinels, and more particularly alumina-
magnesia spinels.
The process consists fundamentally in igniting a very intimate mixture of the
oxides more particularly alumina and magnesia with 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 mixed oxides assumes the crystallised or crystalline form, thus forming a
chemical combination akin to the natural spinels. A portion of the individual
oxides may also crystallise as such alone.
The mixture of the oxides with the carbon may be produced among other
methods by evaporating a moderately dilute solution of the mixed chlorides of the
metals in the presence of the carbon-hydrochloric acid escapes and the alumina is
precipitated as such in the pores and interstices of the carbon. The chloride of
magnesium may require further treatment before being completely converted into
magnesia. The more thorough conversion into magnesia may be effected by a
gentle ignition in a current of steam or by other means. A larger proportion of
chloride of magnesium may also be used at first and after evaporation the excess
of that salt may be removed by solution in water. The evaporation may be
repeated once or oftener.
Solutions of organic salts of the metals may also be evaporated in presence of
the carbon and on ignition carbon will also be obtained in some cases from such
salts.
The sole object in such evaporation or any equivalent procedure is to obtain a
very intimate mixture of the oxides with the carbon.
The carbon used may be a mixture of wood charcoal and lamp-black and the
carbon may have been previously purified by any suitable means.
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 oxides reckoned together and carbon in the proportion of one part by
weight of oxides to one and a quarter of carbon. No absolutely definite proportion
is necessary. As regards the proportion of the oxides to each other about seventy
per cent. of alumina may be used and the remaining thirty per cent. may consist
chiefly of magnesia. The dried mass may in some cases contain a certain amount
of carbonic acid in combination consequent on certain forms of preparation. Its
presence should not be overlooked in reckoning weights. A small proportion of
the oxides or other compounds of chromium of iron of cobalt or of other metals
may be added when desired these latter compounds being used chiefly to com-
municate colours to the crystals. Other substances may also be added to prevent
or correct colours in the crystals.
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 oxides
with the carbon.

page_text: 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 cages of wire may be
employed to make the balls or bricks hold better together. After being formed
they may also be exposed to a slow current of steam at a gentle heat as already
spoken of in describing the evaporation for the purpose of expelling more of the
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 a considerable part of the water
both combined and uncombined. This steaming and ignition of the balls or bricks
is preliminary to the main ignition in carbonic acid gas.
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 reconverted
to carbonic acid and be 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. No absolutely definite degree of temperature is necessary.
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 utilisation of the carbonic acid.
The main ignition may be conducted at the pressure of the atmosphere. If
artificial pressure be employed, the apparatus must be of increased strength.
Dated this Fourteenth day of October 1892.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.
COMPLETE SPECIFICATION.
New or Improved Process for the Production of Crystals or
Crystalline Masses.
I, JAMES MORRIS, D.Sc., 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 colored or colorless such crystals
or crystalline masses being chemically akin to the crystals or stones found in nature
and which are generally known as spinels and more particularly alumina-magnesia
spinels.
The process consists fundamentally in igniting a very intimate mixture of the
oxides, more particularly alumina and magnesia, with 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 mixed oxides assumes the crystallised or crystalline form, thus
forming a chemical combination akin to the natural spinels. A portion of the
individual oxides may also crystallise as such alone.
The mixture of the oxides with the carbon may be produced, among other
methods, by evaporating a moderately dilute solution of the mixed chlorides of the
metals in the
presence of the carbon. Hydrochloric acid escapes and the alumina
is precipitated as such in the pores and interstices of the carbon. When chloride
of magnesium is used along with the chloride of aluminium it may require further

page_text: treatment before being completely converted into magnesia. The more thorough
conversion into maguesia may be effected by a gentle ignition in a current of steam
or by other means. A larger proportion of chloride of magnesium may also be
used at first and after evaporation the excess of that salt may be removed by
solution in water. The evaporation may be repeated once or oftener.
The sole object in such evaporation, or in any equivalent procedure is to obtain
a very intimate mixture of the oxides with the carbon.
The
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.
evaporation 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
mass may then contain the oxides reckoned together and carbon in the proportion
of one part by weight of oxides to one and a quarter of carbon. No absolutely
definite proportion is necessary. As regards the proportion of the oxides to each
other, when alumina and magnesia are used, about seventy per cent. of alumina may
be used, and the remaining thirty per cent. may consist chiefly of magnesia.
Compounds of chromium, of iron of cobalt, or of other metals may be added,
when desired, to the original solution of the chlorides, or other salts, these
compounds of chromium etc. being used chiefly to communicate colours to the
crystals. 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 chromium, iron,
cobalt etc. 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 compounds consisting largely of alumina
in the crystallised or crystalline form.
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 a most intimate mixture of the
oxides 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 they may also be exposed to a slow
current of steam as already spoken of in describing the evaporation for the
purpose of expelling 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 closed, or almost closed vessels, the ignition being
made to free them from a considerable part of the remaining water both combined
and uncombined. The 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
to carbonic acid, and used in subsequent ignitions or be otherwise utilised.
The ignition of the mixture of oxides and carbon in the form of balls or bricks or
in any other suitable form, may be made, by preference continuously, or at least
Less
without very frequent interruption from fifty to five hundred hours or more.

page_text: 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
compounds of alumina to crystallise in.
The average temperature' employed in the main ignition may be a moderate
to fairly bright red in the former case somewhat increased towards the end of the
operation. No definite degree of temperature is necessary.
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 oxides 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 arrange-
ments 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.
The purity of the resulting crystals or crystalline masses will largely depend on
the purity of the materials used. A little of the carbon may, in some cases, become
incorporated or combined in the crystals or crystalline masses. Traces of carbon
have been found in beryls and emeralds. Whatever may be the amount of carbon
in some individual crystals the crystals or crystalline masses, obtained by my process,
consist, collectively, chiefly or entirely of alumina and magnesia, or of alumina and
such oxide or oxides as may take the place of the magnesia. In other words if a
considerable number of the crystals or crystalline masses be tested or analysed at
ouce, they shall be found to consist, all reckoned together, chiefly or entirely of
alumina and magnesia or of alumina and such oxide or oxides as may take the place
of the magnesia.
Although the object of this invention is primarily to produce crystals consisting
individually of alumina and magnesia, or of alumina and some other oxide or oxides
in place of the magnesia, thus forming compounds chemically akin to the spinels
found in nature, it may not be possible, in some cases, to prevent a portion of the
alumina, or of the other oxides, from crystallising individually as such alone.
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, or other oxides, 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 crystals or crystalline masses, consisting chiefly or entirely of alumina
and magnesia or of alumina and such oxide or oxides as may take the place of the
magnesia.
I do not seek to explain why the oxides, under the influence of the carbonic
acid gas, assume the crystallised or crystalline form. Sir James Hall found that

page_text: 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
The value of the
mineralogists in Germany and found to be in the main correct.
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 chemically akin to the crystals or stones found in nature, and which
are generally known as spinels and more particularly alumina-magnesia spinels, by
igniting an intimate, or very intimate, mixture of alumina and magnesia and carbon
or of alumina and other oxide or oxides and carbon in a current of carbonic
acid gas.
2. The production of crystals or crystalline masses, such crystals or crystalline
masses being chemically akin to the crystals or stones found in nature, and which
are generally known as spinels, and more particularly alumina-magnesia spinels, by
the action of carbonic acid gas on an intimate, or very intimate, mixture of alumina
and magnesia and carbon, or of alumina and other oxide or oxides and carbon, the
mixture being exposed during the greater part, or the whole, of the main process,
to a temperature of moderate to fairly strong ignition.
Dated this 23rd day of June 1893.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.