An Improved Method of Making Coloured Tiles for Flor building Furposes.
Year: 1896

page_text: Date of Application, 29th Oct., 1896
PROVISIONAL SPECIFICATION.
An Improved Method of Making Coloured Tiles for Flor
building Furposes.
I, JAMES WEST KNIGHTS of 1 Sidney Street Cambridge in the County of Cam-
bridge, Analyst do hereby declare the nature of this invention to be as follows:-
I mix together Silica and Hydrate of Calcium, both in fine powder, in the
proportion of about four parts of silica to one part of hydrate of calcium, but the
exact proportions are not important, and moisten it with water in such proportion
that it is in the form of a damp powder that will adhere into a solid block under
heavy pressure-the quantity of water required is about ten per cent, but will vary
with the fineness of the powder and the amount of pressure that is brought to
bear on it in the subsequent operation.
This damp powder is then placed in a mould and pressed into a solid block of
the shape and size required to form a tile or other ornamental building block.
The solia block is then dried either in a hot room or by standing in the open
air.
When dry it is moistened with a solution of silicate of soda or silicate of potash
or a mixture of the two, and again dried, this process of moistening with solution
of silicate and drying is repeated until a requisite degree of hardness is imparted
to the block, in most cases about three or four times would be sufficient.
The strength of the silicate solution may vary according as the block is more
or less porous, the more porous the block is, the stronger the solution may be
used, but I find it best to use a solution that has a specific gravity of between
1.050 and 1.100.
When the hardening is completed the block can be washed in water to remove
any soluble alkali it may contain, and finally dried.
If the ingredients as named above be used, the tile or block produced will be
white, to produce coloured tiles a small quantity of any suitable colouring matter
must be incorporated with the dry mixture of silica and hydrate of calcium at
the commencement of the operation, and in sufficient quantity to give the desired
tint.
Dated this 28th day of October 1896
COMPLETE SPECIFICATION.
An Improved Method of Making Coloured Tiles for Floors or
Building Purposes.
I, JAMES WEST KNIGHTS of 1 Sidney Street Cambridge in the County of Cam-
ridge, Analyst, do hereby declare the nature of this invention and in what
[Price 8d.]

page_text: manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
This invention relates to an improved process of making coloured tiles for floors
or building purposes.
The materials used in the composition of the tiles are hydrate of calcium (slaked
lime), silica in the form of powder and silicate of soda or silicate of potash in
solution in water, together with colouring matters, such as oxide of iron, venetian
red, ochres, umbers, lamp black, ultramarine or the like.
The silica may consist of ground flint, ground quartz, or very fine quartz sand
and should be fine enough to pass through a seive having about fifty meshes to
the inch.
The strength of the solution of silicate of soda or potash may vary considerably
without detrimental effect on the process, but I find it best to use a solution having
a specific gravity of between 1.050 and 1.100.
To make the tiles I take of slaked lime 20 to 30 parts, by weight, and of selica
70 to 80 parts and intimately mix them in a mortar mill or other mixing apparatus
and add to the mixture the requisite quantity of colouring matter, say for red
tiles from 5 to 10 per cent of red ochre or for black tiles about 5 per cent of lamp
black, and for other colours the quantity of the various colouring matters that may
be required to give the desired tint; the mixing is continued until the colour is
equally diffused through the whole mass, then water is added to make the mass
slightly damp, but not in sufficient quantity to make it wet or plastic, about 5
or 10 per cent of water will be required.
The mixture which is now a semi dry powder is formed into tiles by being
pressed in an ordinary tile press, and the tiles are dried in heated rooms or in a
current of air.
When the tiles are dry they are hardened by being dipped in the solution of
silicate of soda or potash for a few minutes or long enough to allow the solution
to penetrate, usually three or four minutes are sufficient, and are again dried. The
operation of dipping in silicate solution and drying may be repeated once or
twice, after which the tiles will be hard and ready for use.
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 manufacture of tiles consisting of hydrate of calcium (slaked lime),
silica and colouring matter, formed by pressing the ingredients mixed in the
form of a semi-dry powder, into slabs or blocks, and subsequently subjecting
them to the action of an alkaline silicate solution, substantially as described.
JAMES WEST KNIGHTS.