with Si and with A
Year: 1887

page_text: 1, JOHN DAVENPORT, Agent, of Stoke on Trent, in the County of Stafford, do
hereby declare the nature of the said 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 production of improved compounds especially applicable
to the manufacture of fire bricks, furnace and cupola linings, retorts, crucibles, muffles,
saggers, quarries, tiles, fire proof safes, and for general use where a high degree of
fire resisting quality is required: and consists essentially in the application and use in
the production of such compounds and products of Sulphate of Baryta in combination
with Silex or Silica and with Alumina."
For purposes of economy in the production of such compounds I prefer to use as the
base thereof any suitable natural product containing Silex or Silica and Alumina
in respectively sufficient abundance to be of utility for the purpose of the Invention.
Among the most serviceable of such substances is strong silicious sand of the kind
found principally in the Limestone districts of Derbyshire and Staffordshire and
commonly known as Ganister sand or fire clay, and which usually contains from about
80 per cent. to a somewhat higher percentage of Silica, and from about 9 to about
10 per cent. of Alumina together with small quantities of water and other matters
which are mostly eliminated in the following treatment and do not materially affect
the fire resisting qualities of the product; as such relative proportions of silica and
alumina are approximately those which are of most advantage when used for the
purpose of the Invention in combination with Sulphate of Baryta as herein described.
Bricks or fire clay as hitherto prepared from such basic material possess serious
disadvantages being lacking in homogeneity and liable to speedy disintegration when
subjected to any considerable superincumbent weight, as when used in the construction
of the lower parts of furnace linings and hence are comparatively valueless.
According to the present improvements, I avoid such defects and am enabled to
produce a homogeneous plastic compound containing a high percentage of silica, and
which can be worked or moulded into any desired shapes, and a product practically
D

page_text: indestructible after the manner of asbestos, and which will bear without liability of
disintegration sudden changes of extremes of temperature and intense pressure, and
will be especially applicable to such uses as aforesaid.
In carrying the Invention into effect I find the most satisfactory results are attained
when the Alumina and Sulphate of Baryta are in about the same quantities by weight,
and when the Silica, Alumina and Sulphate of Baryta are in the relative proportions
of about 80; 10 and 10 per cent. by weight; so to a silicious sand containing about
such proportions of silica and alumina I add about 10% by weight of Sulphate of
Baryta which is also commonly known as Calk Barytes or Heavy-spar, and is also
found in a natural state in lump form frequently near deposits of such sand.
If a compound possessing fire resisting qualities in a less degree is required, then
other natural products may be used containing a less proportion of Silex, in which
case I still prefer to use about 10 per cent. of Sulphate of Baryta, and also add the
Alumina in proportion as that of the silica decreases; for instance, if silicious rock be
used instead of silicious sand, I add thereto about 10 per cent. of Alumina, with an
equal proportion of the Sulphate of Baryta.
The said sand is found practically free from any deleterious foreign matter and can
be used in its natural condition without other preparation, but I prefer to use the
Sulphate of Baryta in a finely crushed or powdered form.
The admixture is thoroughly well incorporated by any suitable mechanical or other
means in order to effect an equable distribution of the Sulphate of Baryta in the mass,
from which fire bricks or other articles may be pressed or moulded in any usual way
by any suitable machinery or by hand, and may then be baked in the ordinary way,
the resultant product attendant upon the combination of the Sulphate of Baryta and
the Alumina being extremely durable, homogeneous and possessing considerably
greater fire resisting quality than Silica possesses alone, or in any combination alone
with Alumina.
If the said sand or clay is used in a state containing its natural proportion of
moisture the above materials may be compounded without any added water, but if
such sand or clay is used in a dry state I then prefer to add to the compound sufficient
water to render it sufficiently plastic to allow of its being thoroughly well worked.
Having now particularly described and ascertained the nature of my said Invention,
and in what manner the same is to be performed, I declare that what I claim is :-
The application and use for the production of fire resisting compounds and products
of Sulphate of Baryta in combination with Silex or Silica and with Alumina.
Dated thin 12th 11007
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C.,
Agents for the Applicant.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C.,
Agents for the Applicant.