IMPROVEMENTS IN THE MANUFACTURE OF BASIC FIRE-BRICKS AND OTHER FIRE WARE GOODS
Year: 1880

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF BASIC FIRE-BRICKS AND OTHER FIRE WARE GOODS."
A communication from abroad by Jean Baptiste Marie Prosper Closson, of
Paris, France,
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 21st December 1880.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "IMPROVEMENTS IN THE MANUFACTURE OF BASIC FIRE-BRICKS
AND OTHER FIRE WARE GOODS." [A communication from abroad by Jean
Baptiste Marie Prosper Closson, of Paris, France.]
This Invention relates to the manufacture of basic fire bricks, crucibles, tuyeres,
pipes, and other fire resisting products of magnesia or calcined dolomite or lime,
and it consists mainly in the employment of a gelatinous substance of animal or
vegetable origin, such as glue, gelatine, vegetable gelatine, Japanese cement, fucus,
and their congeners, and in some cases sugar and molasses, as a binding material for
the magnesia or other basic material, and in the method of manufacture hereafter
described.
I take (1) old magnesia bricks, broken and partly ground to powder more or less
fine, the proportion varying from, say, 1/, to %, according to the article to be
made. (2) Magnesia in powder. I moisten with a solution of gelatine, or other
substance above specified, the proportion of the gelatine solution being generally
from 1% to 3% or more in certain cases. The basic material is made into a
paste sufficiently plastic to be moulded into bricks or blocks of any shape, hollow
bricks, crucibles, pipes, tuyeres, and other fire-resisting articles, as with ordinary
clay, without requiring the use of a press.

page_text: The moulded bricks, blocks, crucibles, or other fire-resisting articles, after being
fired at a very high temperature, are much superior to those heretofore made of
basic materials, being homogeneous, hard enough to scratch glass, and to a certain
extent translucid like porcelain.
To obtain a certain degree of porosity when required I may add charcoal to the
paste in certain cases. I also make a slip in the same manner, whereby articles
moulded in several pieces may be united perfectly, or for joints and in setting
bricks I may simply dip the pieces or bricks in a very dilute solution of the
material above mentioned and sprinkle the surfaces to be joined with a little
powdered magnesia.
The same methods of manufacture are equally applicable in the case of dolomite
and of lime.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the
21st June 1881.
"
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
IMPROVEMENTS IN THE MANUFACTURE OF BASIC FIRE BRICKS
AND OTHER FIRE WARE GOODS." A communication from abroad by Jean
Baptiste Marie Prosper Closson, of Paris, France.
The manufacture of fire bricks from magnesia has been very limited hitherto in
consequence of the cost of the magnesia and the difficulty of manufacture.
Heretofore the magnesia was first calcined at a high temperature, and after cooling
and pulverization it was partially hydrated and thoroughly stirred. The magnesia
should then be sufficiently plastic to be moulded. The bricks were moulded in a
hydraulic press and subjected to considerable pressure, and after being dried were
burnt at a high temperature. Bricks have also been made from dolomite for lining
converters and furnaces used in making steel from phosphoric pig iron. The
dolomite was first reduced to powder and made into a paste with water, then
moulded into bricks and burnt at a high temperature. The shrinkage due to the
evolution of carbonic acid was however very great, and the bricks were defective
and possessed little durability. It has been proposed to make better bricks by
first calcining the dolomite, making it into a paste with petroleum, moulding it into
bricks and burning them at a very high temperature, but this process has not as
yet been used commercially, and although the products are more homogeneous than
those made as above they have not much hardness.
It has been discovered that petroleum gives the same results with magnesia and
also with lime. In the case of dolomite economical processes of manufacture are
necessarily employed, and in any case the product is unstable owing to the lime
contained.
This Invention relates to the manufacture of basic fire bricks, crucibles, tuyeres,
pipes, and other fire resisting products of magnesia or calcined dolomite or lime,
and it consists in the employment of a gelatinous substance of animal or vegetable
origin, such as glue, gelatine, vegetable gelatine, Japanese cement, fucus, and their
congeners, and in some cases sugar and molasses, as a binding material for the
magnesia or other basic material, and in the method of manufacture hereinafter
described.
Ordinary fire bricks composed of silica and alumina are usually made of—
(1) old overburnt bricks, (2) old bricks, (3) silica, (4) raw clay (silica and
alumina). The proportions vary according to the products to be made. The whole
is not finely pulverised, but is partly fine powder and partly small lumps, which
are, in fact, cemented together, forming a sort of mortar. In this way shrinkage
and cracking are avoided. I proceed in the same way for magnesia bricks, that is
to say:-
I take (1) old magnesia bricks, broken and partly ground to powder more or less
fine, the preportion varying from, say, 1/3 to 2/,, according to the article to be
made; (2) magnesia in powder. I moisten with a solution of gelatine, or other
substance above specified, the proportion of the gelatine being generally from 1%
to 3%, or more in certain cases. The basic material is made into a paste
sufficiently plastic to be moulded into bricks or blocks of any shape, hollow bricks,
crucibles, pipes, tuyeres, and other fire resisting articles, as with ordinary clay,
without requiring the use of a press. The moulded bricks, blocks, crucibles, or
other fire resisting articles, after being fired at a very high temperature, are much
superior to those heretofore made of basic materials by the processes herein before
referred to, being homogeneous, hard enough to scratch glass, and to a certain

page_text: extent translucid like porcelain. To obtain a certain degree of porosity when
required I may add charcoal to the paste in certain cases.
I also make a slip in the manner above described, whereby articles moulded in
several pieces may be united perfectly. In certain cases for joints instead of slip
in setting bricks or blocks I may simply dip the bricks, blocks, or pieces in a very
dilute solution of the material above mentioned and sprinkle the surfaces to be
joined with a little powdered magnesia. The same method of manufacture is
equally applicable in the case of dolomite and of lime, but these are of less
importance than magnesia.
Excellent results may be obtained by calcining the magnesia at the highest
temperature attainable, then adding to calcined dolomite reduced to coarse powder
or lumps a paste composed of powdered magnesia (overburnt or not) and glue
dissolved in water. The proportion of glue depends on the products to be made,
and in some cases would be exceedingly small. When the articles are submitted to
sufficient pressure scarcely any water is used. The products should be perfectly
dry before firing.
Having described the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
hereinbefore in part recited Letters Patent is,-
In the manufacture of basic fire bricks and other fire ware goods of magnesia or
calcined dolomite or lime, the employment of gelatinous substances of animal or
vegetable origin, such as glue, gelatine, vegetable gelatine, Japanese cement,
fucus, and their congeners, substantially in the manner and for the purpose
specified.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Twenty first day of June, A.D. 1881.