Material Applicable for Structures, Vessels, and other Uses.
Year: 1886

page_text: Date of Application, 31st May, 1886.
Complete Left, 26th Feb., 1887.
Complete Accepted, 7th Apr., 1887.
of Material Applicable for Structures, Vessels, and other Uses.
I, JEAN BAPTISTE FERDINAND FRÉDUREAU of 23 Boulevard de Strasbourg, Paris
France do hereby declare the nature of this invention to be as follows:-
This invention relates to the treatment of slate, schist and such like minerals and
particularly of their waste fragments for the production of material applicable for
structural purposes, for forming vessels, pipes and the like, for electrical insulation
and for other uses.
For this purpose, powdered schist or slate is made up into a paste with solution of
silicate of potash or of soda, the paste is moulded into the desired forms and the
moulded pieces are dried, it may be at ordinary temperatures, but preferably with the
aid of a little heat. The solid material thus produced is at once applicable for structural
purposes or for making tanks, vessels, pipes &c. and is capable of being readily
worked by saws, planes or other tools; it is especially applicable for use in laboratories
or chemical works, as it is not subject to corrosion by acids. The material can be used
as an electrical insulator, being in that case preferably impregnated with paraffin, tar,
petroleum or the like. The dried material may be gradually heated up to a white heat,
whereby it is brought to the condition of a refractory stone of great durability,
particularly applicable for furnaces or furnace vessels.
ABEL & IMRAY,
28, Southampton Buildings, London, W.C.,
Agents for the Applicant.

page_text: Treatment of Slate, Schist, and Waste thereof for the Production
of Material Applicable for Structures, Vessels, and other Uses.
I, JEAN BAPTISTE FERDINAND FRÉDUREAU of 23 Boulevard de Strasbourg, Paris,
France 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 treatment of slate schist and such like minerals and
particularly of their waste fragments for the production of material which I term
Ardoisite" applicable for structural purposes, for forming vessels pipes and the like,
for electrical insulation and for other uses.
For this purpose, I mix the pulverized schistous rocks with the various alcaline
silicates either taken separately, or combined in convenient but variable proportions
according to the nature of the schists, forming a paste in which the silica enters in a
greater proportion than in the natural product.
In such conditions, the silica, saturated by the oxygen, becomes inalterable and
cements the molecules in presence, giving them a greater solidity than that of the
ordinary slate schists, as I have been able to compare with the slates coming from the
Silurian and liasic formations.
The operation being made at an ordinary temperature, the conversion is accomplished
in a relatively short time, and the product becoines hard after a few hours of drying
by the action of a moderate degree of heat.
If, on the contrary, after a previous drying, the product is submitted to a more
elevated temperature, bringing this temperature from a cherry red to a white heat
during a few hours, the conversion goes on, increasing and the mass, by the action of.
heat and silicious emanations, is transformed, taking the intermediate texture between
the amorphous and crystalline state, a condition which is known under the generic
term of crystallite.
As an example corresponding to every schistous formation existing on the surface of
the earth, I will examine the chemical composition of the various slate bearing strata
existing in France.
These strata can be divided into three distinct series whose average compositions
are the following:
101
317
2

page_text: These different analyses shewing the relative proportions of the Silica, Alumina and
Alkalies contained in the slate, allow of the conclusion that, relatively to the various
industrial applications to which the manufacture of "Ardoisite" can be put, it is
necessary to employ either separately, or mixed together, the schists furnished by the
Silurian and linsic formations.
The schists richer in Silica should be preferred for obtaining a greater hardness and
a greater insulating power, whilst it is necessary to mix together a certain proportion
of Silurian with liasic schists when "Ardoisite is to be applied for the manufacture
of earthenware and porcelains which must receive a glazing; a certain proportion of
lime in the paste being necessary to prevent the glazing from splitting.
"
If by way of example it is desired to transform into Ardoisite " the silurian
schists of the Angers formation, it will be seen that these schists contain, in average
composition, 35 parts of Alumina and 57 of Silica corresponding approximately to
the formula (Al, О, 2 Si O₂) which contains 37 of Alumina and 63 of Silica for 100
of Slate.
31
If to these pulverized slate schists is added some silicate of potash or soda soluble in
water, whose formulæ, when they contain most Silica, are (Ko, 3 Si O,) and (Na O,
3 Si Ó,) it will be seen that there are added to the mass about 47 parts of potash or
soda för 125 parts of silica. Therefore, if for example there are introduced into
100 parts of pulverized slate schists 20 per cent of silicate of potash or soda, there are
added to the mass 5 parts of potash or soda for 15 of silica.
In these conditions, 100 parts of Angers Slate schists plus 20 per cent of silicate of
potash or soda, give a product containing :

page_text: 1st) for its richness in Silica (two thirds).
2nd) for its richness in Alumina (nearly one third). ..
3rd) for its small proportion of Alkali (4 per cent).
The very small quantity of alkalies gives to "Ardoisite" exceptional qualities of
durability.
For obtaining very pure
"Ardoisite" products, it is sufficient to wash previously
with acids the pulverized slate schists for freeing them from the oxides of iron.
The industrial results of these various operations are characterized :
1st. As regards the products obtained at ordinary temperature: by a paste which
can be worked by hand, moulded, rolled and mechanically compressed.
"
2nd. By a solidity after drying that makes it useful without any other operation;
"Ardoisite can therefore be worked, sawed, drilled and planed in the same manner
as wood.
3rd. As regards the burnt product, by a metamorphosis which is increased
according to the degree of temperature, without this product undergoing any
appreciable contraction.
33
4th. By that, before as after burning, "Ardoisite can be made a perfect insulator
of electricity; in this respect it can be used in a great number of cases, and especially
in place of Ebonite, Guttapercha India-Rubber &c.
5. By that, after "Ardoisite" has been submitted to a moderate temperature, it is
not only not acted upon by the atmospheric agents, but even at ordinary temperature,
or after burning, it is not acted on by acids, except hydrofluoric acid. Therefore
"Ardoisite" can be used in a great many cases for all pipes and vessels for chemical
products.
6. By that "Ardoisite" can receive in its mass every coloration that can be
obtained by introducing metallic oxydes. Therefore "Ardoisite" can be used in a
great many cases in building and the Ceramic arts.
7. By that "Ardoisite" can receive a glazing, which extends its applications.
8. By that "Ardoisite" can be tempered in baths conveniently prepared, either
with water, or with oil or with any fatty substance.
9. By that "Ardoisite" can be impregnated hot with paraffin, tar, pétroleum,
benzine or sulphur, which improves its insulating and impervious properties.
Ardoisite can therefore be used:
1. For the manufacture of building materials, bricks and other moulded products,
slates, tiles, slabs, squares, pipes and decorative materials. These various materials
can be, at will, tempered and rendered entirely impervious.
2. For the manufacture of laboratory furnaces, ordinary crucibles, and more
refractory crucibles, in mixing the pulverized schists with a certain proportion of
graphite.
3. For the manufacture of vases and vessels for acids, laboratory tables, coatings
for acid vats, cocks and acids pipes, and especially, for its employment in every case
where the resisting properties of lead are now used.
4. For the manufacture of earthenware and other articles of crockery, buttons,
pearls, &c.
5. For the manufacture of incombustible tables, pieces of furniture and other
articles.
6. As electrical insulators "Ardoisite" alone or impregnated with paraffin being
an insulator that withstands variable temperatures.
7. For the manufacture of mouldings, frames and artistic articles that can be

page_text: made either by hand or by moulding-"Ardoisite" being without any appreciable
contraction.
Having now particularly described and ascertained the nature of this invention and
in what manner the same is to be performed, I declare that what I claim is :—
1. The herein described new manufacture consisting of ground slate or schist mixed
with solutions of silicate of potash or soda to form a paste which is moulded into any
desired form and dried with or without the application of heat.
2. The herein described processes for producing the compound referred to in the
preceding claim.
1000
ABEL & IMRAY,
Agents for the Applicant.