Improvements in the Manufacture of Fire Bricks and Fire Proof Mortar.
Year: 1896

page_text: Date of Application, 2nd Oct., 1896
Complete Specification Left. 6th May, 1897-Accepted, 2nd Oct., 1897
Improvements in the Manufacture of Fire Bricks and Fire Proof
Mortar.
I ARCHIBALD CAMPBELL PONTON of 45 Ashburnham Road Bedford in the County of
Bedfordshire Architect, do hereby declare the nature of this invention to be as
follows:-
I employ finely ground burnt flints with or without the addition of washed siliceous
fine sand. Into each ton of the siliceous matter I mix about 20 gallons of Silicate of
Soda or Potash separately, or in combination. I also mix about three or four hundred
weight of damped finely cut fibre such as heath, hay, straw, chaff, cocoa-nut fibre, jute,
hair or such like separately, or combined in any manner so as to produce about
66 per centum of interstitial spaces in the completed Fire Bricks. I use these
materials when freshly prepared and tempered together, and I mould them into the
form of bricks by any of the ordinary methods and I dry them, and highly burn them
in any suitable kiln for high & intense burning using sufficient heat to volatilise the
soda or potash and also sufficient heat to crystallise the siliceous particles together
into very porous & vesicular Fire Bricks. I employ the same materials hereinbefore
mentioned for the preparation & manufacture of Fire proof Mortar.
Dated this First day of October One thousand eight hundred and ninety-six.
Improvements in the Manufacture of Fire Bricks and Fire Proof
Mortar.
I, ARCHIBALD CAMPBELL PONTON, of 45 Ashburnham Road, Bedford, in the County
of Bedfordshire, Architect, 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 manufacture of a highly refractory pure silicious
material in such a state of aggregation as to be suitable for the manufacture of fire
bricks, crucibles, and other articles where great resistance to a high temperature is
necessary and also for a fire-proof mortar or ceinent to be used in conjunction with
such articles.
It is already known that pure silica as it occurs in nature is a most refractory
substance, and that an artificial product composed of ground burnt flint cemented
D
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page_text: together, whether compressed or of normal density and highly burnt, is also very
refractory, and it has been ascertained that neither natural pure silica nor the artificial
pure silica above described is suited for fire bricks, crucibles, or fire-proof mortar,
owing to its liability to splinter or disintegrate under the influence of great heat, that
may be more or less of an intermittent character.
Hitherto, moreover, owing to this circumstance, all so-called silica fire bricks have
been composed of silica in combination with one or more bases forming silicates, so
that both the chemical and physical properties of the pure silica are destroyed, the
hase or bases acting as a flux and causing the fire-bricks or fire-proof mortar to fuse
and form slag under the influence of great heat.
Now the object of my invention is to produce a fire-brick and fire-proof mortar of
silien that shall retain the highly refractory property of pure silica and shall not be
liable either to fuse and produce slag or disintegrate under the influence of even long
continued and very intense heat, such as is used for the manufacture of steel or other
substance requiring a very high temperature that may be more or less of an
intermittent character. The finished product being practically pare silica.
In carrying my invention into effect. I employ pure silicious powder obtained from
ground burnt flint, washed fine silicious sand or other suitable source, mixed with
certain proportions of silicate of potash or silicate of soda, either alone or both
together, or other suitable flux, and to this I add natural or artificial fibrous material
or materials, such as heath, hay, straw, chaff, coenanut fibre, jute, bulrushes, wood
fibre, wool, hair or the like in a more or less finely divided state to suit requirements,
damped with a suitable quantity of water.
These materials, after intimately mixing in a mortar mill or other suitable mixing
machine while adding the fibrous material and water until the required degree of
plasticity is obtained, I mould into the required form of bricks by any convenient
method, such as by pouring or gently pressing the mixture into moulds, or, when
more plastic, by using any well-known kind of brick-making machines; I then dry
said bricks, and afterwards burn them at a very high temperature in any suitable
kiln, the degree of heat used being sufficient to completely volatilize and drive off
the alkaline base or bases, or other suitable flux, together with the water and fibre,
leaving the silica behind practically consolidated by a process of crystallization, or,
with very high temperatures, by a process of combined crystallization and fusion."
Thus the alkaline base or bases or other flux having been volatilised so that none
remains in the fire brick or mortar, the silica of which they are composed will not fuse
and form slag nt the very high temperatures now produced by the Siemens
Regenerative Gas Furnaces in the manufacture of Steel.
The fibre and water serve the purpose of binding the mass of the substance together
before burning in the kiln, and when burnt and driven off in the shape of gas and
steam, leave the brick or finished product in a more or less vesicular or cellular state,
the said brick when finished, having throughout the mass of its substance a number
of interstitial spaces, the latter varying in number according to the quantity of water
and fibre employed in the manufacture, and it is owing to this said vesicular state.
that the splintering or fracture of the fire bricks or finished product under the
influence of the great heat of the nature now employed for manufacturing purposes,
is more or less obviated. The said brick or finished product may have the very low
abnormal apparent density or specific gravity of 5, or the Sp. G. of 1-5, or any
intermediate Sp. G. between these; such for example as Sp. G. -7, or 9 or 11, according
to the amount of water and fibre used, the greater the quantity of fibre and water
employed, the lower being the apparent density of the resulting product, a brick with
Sp. G. of 1-15 having about 50 per cent. of its volume occupied, by interstitial spaces.
I may, moreover, still further reduce this apparent density if required by mechanically
piercing holes in the mass during the process of moulding.
I do not rigidly confine myself to proportions and quantities hereinafter specified
of the various materials, as it will be obvious to any person conversant with this class
of manufacture that such proportions and quantities will necessarily vary according
to the degree of vesiculation or porosity required in the finished product.

page_text: For example, for a finished product having about 60 per cent. interstitial spaces and
Sp. G. of about 92 I use to produce 1,000 bricks, about-
2 tons of ground flint or other suitable form of silica.
24 gallons of silicate of soda or other suitable flux.
176 gallons of water.
These proportions are for stiff plastic results, but for casting purposes, such as
crucibles, retorts, and the like, when the material is required in a more liquid state, I
may reduce the fibre even to the extent of practically omitting it, or use the fibrous
materials with a larger amount of water.
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) In the manufacture of fire bricks, crucibles, fire-proof mortar or cement and
other articles intended to resist great heat, the use of ground burnt flint or other
suitable form of silica with an alkaline silicate or other suitable flux and water
substantially as and for the purpose herein described.
(2) In the manufacture of fire bricks, crucibles, fire-proof mortar or cement, and
other articles required to resist great heat, the use of ground burnt flint or other
suitable form of silica with an alkaline silicate or other suitable flux, water and natural
or artificial fibres or fibrous material or materials substantially as and for the purpose
herein described.
(3) For fire bricks, crucibles, fire-proof mortar or cement, and other articles required
to resist great heat the production of a strong porous material of practically pure
silica from loosely aggregated powdered silica by means of an artificial process
substantially as described.
(4) For fire bricks, crucibles, fire-proof mortar and cement, and other articles
required to resist great heat, the use of a product composed of practically pure silica
substantially as described.
CASTLE SMITH,
"Invention " Office, Mitre Court, Fleet Street, London, E.C.,
Agent for the Applicant.