Improvements in the Utilization of Waste Sand from Glass Grinding Works and other Materials for the Manufacture of Hones, Holy Stones, Grind-stones, and the like Blocks for Abrasive Grinding or Polishing Purposes, Crucibles, Emery Corundum, and other Wheels, Bath Fire or other Bricks, Tiles, Ornamental or other Slabs, Tablets, Switch Boards, Imitation Porcelain and Pottery and the like.
Year: 1899

page_text: PROVISIONAL DITUIFICATION.
Improvements in the Utilization of Waste Sand from Glass Grinding
Works and other Materials for the Manufacture of Hones, Holy
Stones, Grind-stones, and the like Blocks for Abrasive Grinding
or Polishing Purposes, Crucibles, Emery Corundum, and other
Wheels, Bath Fire or other Bricks, Tiles, Ornamental or other
Slabs, Tablets, Switch Boards, Imitation Porcelain and Pottery
and the like.
We, WILLIAM WINDLE PILKINGTON, J.P., of The Hazles, Prescot, in the County
of Lancaster, Glass Manufacturer, and WILLIAM REGINALD ORMANDY, D.Sc., of
142, Windleshaw Road, St. Helens, in same County, Chemist, do hereby declare
the nature of this invention to be as follows:-
In the manufacture of plate glass, the glass is ground under revolving discs
or plates of iron with sand or emery.
Now by our invention the refuse sand from this operation too fine to be further
used therein and consisting of the original sand finely ground glass, and some
iron, is graded into sizes by being carried by a stream of water through settling
tanks or in any other suitable manner. By this means a uniformly fine material
with sharp edges is obtained. If this graded material be now firmly pressed
together into any required shape and heated until the glass begins to frit or
fuse, and is then slowly allowed to cool, a solid mass remains of the same shape
as that originally furnaced.
Its texture is open or close grained in proportion to the pressure exerted and
of course to the degree of fineness of the material. Where very porous material
is required, as for instance in artificial pumice stone or in bath brick, we may
even mix with the original materials flour or other finely ground organic matter,
or even paste, glue, or other like adhesive. This burns out in the furnacing, and
leaves a much more porous brick or material than where only sand has been
used. When on the other hand very dense bricks are required, clay or chalk
or spent lime from caustic works (Ca C 03) are intimately mixed with the sand
and the bricks shaped and pressed while the materials are slightly moist, or if
Staffordshire blue or brindled bricks are required, ground clinker is mixed with
the sand or sand and clay or sand and lime, the blue colour is obtained by dust-
ing the surface with ground bull dog slag, (a product of the puddling furnace)
and putting a little salt in the furnace. Bricks can also be made by mixing
various quantities of ordinary or sea sand and the glass works refuse sand with
or without clay or carbonate of lime or ground aluminous matter. These mix-
tures can be formed into bricks, tiles, crucibles, imitation pottery ware and the
like, our experiments indicate that first class fire bricks can be made from the

page_text: refuse glass sand with or without a little clay. Where emery stones are required,
the emery with the waste glass works sand or glass ground to a similar degree
of fineness are intimately mixed together and furnaced in like manner, just suffi-
cient glass being added to hold the emery firmly together. If diamond dust
has to be caked together in this way, the diamond dust is mixed with the glass
in like proportion, and formed into blocks of the right shape with or without
the addition of a little adhesive such as gum, glue, or the like. It is then baked
to the required extent under pulverized carbon or a melted metal or in other
ways the air is kept entirely clear from it during heating. By this means the
edges of the diamond dust exposed to the surface or to the pores in the material
are not oxidized. When the material is not required for abrasive purposes, but
for ornamental or building purposes, as when it is used for slabs or the like, we
preferably apply a considerable pressure to the material, and mould it into
shape. Previous however to placing it in the mould or after moulding it, in the
case of tiles and ornamental slabs we may coat it with a glazing or slip and
in the case of slip when it is dry again expose it to heavy pressure. The blocks
are then furnaced in the manner already described. In this way a substitute for
slate, marble and ceramic ware is obtained, and the purest white slabs, and also
imitation terra cotta ware can be made. The material being capable of being
moulded to any shape and coloured to any hue will also be found very useful for
switch boards, ornamental or memorial tablets, grave stones, and the like.
Ornamental slabs can also be made by placing on a flat polished surface broken
refractory glass of various colours, also flat stones and pottery which will not
alter at the heat used, placing them in a suitable pattern or arrangement, and
then backing them with a thick layer of the glass sand, pressing into cakes and
furnacing in the usual manner. The result will be a variegated surface for
ornamental work. The sand can also be coloured to start with and made into
blocks of a given thickness with vertical sides. These blocks can be fitted to-
gether like a tessellated pavement and the whole baked in one mass or in
separate blocks as described, a little sand or other material being placed between
them if desirable to bind them. Where the tiles are baked first, they can be
coloured by being steeped in solutions and then again burnt, thus if they be
soaked in a solution of sulphate of iron and then dried and burnt they produce
various shades of red, according to the amount of sulphate of iron used and
the temperature employed. Similarly nitrate of cobalt and alum produce a blue.
chromate of potash or chromic acid or in fact any soluble chromium compound
will produce a green.
When using blocks made of this material for polishing the glass, it will be
necessary first to rough the glass with the usual iron blocks, then use our arti-
ficial stone blocks. If the sand used. with the artificial stone blocks be kept
separate from the sand used with the iron blocks and clean sand be used in the
first instance with our blocks, no cleaning is required, while even if sand not
quite clean be used, little cleansing is required to almost absolutely rid it from
iron. Where bricks or the like are to be made of pure colour and uniform
combination we prefer to purify the sand first in the following manner, heating
to a red heat with fuel to reduce the iron, separating the iron by magnets re-
oxidising the remaining iron in the sand and either treating it with acids and
washing or with chloride of ammonium and hydrochloric acid to extract the
remaining iron.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool. Patent Agents for the Applicant.

page_text: Improvements in the Utilization of Waste Sand from Glass Grinding
Works and other Materials for the Manufacture of Hones, Holy
Stones, Grind-stones, and the like Blocks for Abrasive Grinding
or Polishing Purposes, Crucibles, Emery Corundum, and other
Wheels, Bath Fire or other Bricks, Tiles, Ornamental or other
Slabs, Tablets, Switch Boards, Imitation Porcelain and Pottery,
and the like.
We, WILLIAM WINDLE PILKINGTON, J.P., of The Hazles, Prescot, in the County
of Lancaster, Glass Manufacturer, and WILLIAM REGINALD ORMANDY, D.Sc., of
142, Windleshaw Road, St. Helens, in same County, Chemist, 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:-
In the manufacture of plate glass, the glass is usually ground and polished
under revolving discs or plates of iron, sand, emery, and rouge being successively
used in the operation. The abrasive materials are rapidly themselves ground
down to an almost impalpable powder and an enormous quantity of this impal-
pable powder accumulates in the neighbourhood of the works. Numerous attempts
have been made for many years past to utilise this waste glass works sand for
brick making, but as far as we are aware in this country at least without prac-
tical success.
The history of these attempts has been as follows:-
In 1883 Mr. Douglas Herman, the head chemist of Messrs. Pilkington
Brothers Limited, proposed and patented a modification of Ransome's method
for making artificial stone, consisting of mixing the sand with silicate of soda
and baking it into bricks with or without treatment with chloride of calcium.
Sample bricks were made in the works of the company with more or less success,
but the cost appeared to be too great for the process to be profitable, and it
was abandoned.
Several years ago it was publicly suggested to make firebrick from this material
and aluminous rock found in the neighbourhood in coal mines. This rock was
to be ground up to a fine powder mixed with the sand and burnt, the propor-
tions proposed being from ten to fifty per cent. of the ground rock to from ninety
to fifty per cent. of the sand.
We are not aware that the process has been worked on a manufacturing
scale, and we have found by experiment that with any of the proportions then
proposed the bricks obtained are not firebrick but on the contrary very fusible.
In 1892 Messrs. Gaskell & Robinson took out a patent for making bricks of
sand with the addition of certain other substances, more especially alkali waste,
clay lime barytes or sulphate of lime and crushed granite. This patent is now
owned by ourselves, but hitherto only a few sample blocks have been made under
it.
Most of these previous inventors looked upon the sand from the glass works as
ordinary sand in no way practically differing from sea-sand or the like.
Now the glass in this waste sand which is 10-30% of the entire bulk has the
effect of fritting or semi fusing when the waste sand is heated to bright red-
ness, and thus adhering to and uniting the neighbouring grains of sand without
these latter fusing or altering their shape. By this means a hard tough block

page_text: is formed from the sand without admixture of any material with it and without
alteration of shape.
By our invention we grade this waste sand into various sizes by causing it to
be carried by a stream of water through settling tanks or in any other suitable
manner. By this means a uniformly fine material with sharp edges is obtained.
If this graded material be now firmly pressed together into any required shape
and fired at the right temperature until the glass begins to frit or fuse and is
then slowly cooled a solid block of the same shape as that originally furnaced
is obtained. Its texture is open or close grained in proportion to the pressure
exerted, and of course to the degree of fineness of the material. Thus if lightly
pressed and fired at a right temperature (cherry red), excellent bath brick is
If
obtained, while if pressed with greater pressure a fire brick is obtained.
organic matter be mixed with the sand before baking, very porous filtering slabs
or blocks are obtained. When very dense bricks are required, we mix clay,
chalk, spent lime from alkali works, or other refractory fine grained material
with it, and press and shape it into bricks while the material is dry or slightly
moist, or if Staffordshire blue or brindled bricks be required ground clinker or
ash is mixed with the waste sand or waste sand and clay or waste sand and lime
or the like. The blue colour is obtained by dusting the surface with ground bull
dog slag (a product of the puddling furnace) and putting a little salt into the
furnace.
The following receipts we have found very useful as regards this part of our
invention:-
Buff bricks.
Glass sand
60 parts.
35 parts.
Strong or top clay
Spent lime from caustic soda works chalk or the like
5 parts.
White bricks.
60 parts
Glass sand
30 parts
Field sand
10 parts
Lime or chalk
For Staffordshire blue or brindled bricks.
The above red brick mixed with 10% clinker, if burnt, in the open kiln and
salted will give a blue brick. The same mixing slightly less fired and without
salting gives a brindle brick.
We have found that there is sufficient glass in the glass sand to cause the
material to adhere when heated even when a considerable quantity of ordinary or
sea-sand has been mixed with it.
For making flooring tiles we prefer to use

page_text: With these or similar mixtures, we can make bricks, tiles, crucibles, imita-
tion pottery ware and the like. For making dense firebricks, we use glass sand
45 parts, clay or aluminous material containing as little iron as possible, 2–5
parts, and 50 parts common sand as free from iron as possible, or for making
firebricks somewhat similar to the Dinas we use glass sand mixed with ordinary
sand together with to 1% limestone, carbonate of lime waste or a correspond-
ing amount of slaked lime and moistened until fit for treatment in a semi-dry
brick press, with a solution of sodium silicate containing one part of 1400
Twaddle sodium silicate to 8 parts of water. This makes the brick firm for
stacking in the kiln. In the same way, emery, corundum, or diamond dust stones
can be formed by mixing the emery, corundum or diamond dust with extremely
fine ground glass to the extent of about one-tenth ground glass to nine-tenths of
the abrasive, mixing them intimately together and furnacing in the manner
already described, except that when diamond dust or the like is used, we prefer
to cover the block entirely with carbon so as to prevent the carbon in the block
being burnt away or else burn them in air-tight muffles, or muffles filled with
combustible gas.
For ornamental blocks, slabs and the like, we prefer to apply
a very considerable pressure to the material, either dry or semi-dry, the greater
the better, up to 2 tons on the square inch, and mould it by this pressure at
once into the shape required. The blocks can now be coated with enamel in
the usual way, either dipped in suitable slips at once and burnt and enamelled
in one operation or burnt first and enamelled in one or more subsequent opera-
tions as is at present customary. In this way a substitute for slate, marble, and
ceramic ware is obtained, and the purest white slabs, and also imitation terra
cotta ware can be made. This material being capable of being moulded to any
desired shape and the slip or glazing being coloured to any required hue, switch
boards, ornamental or memorial tablets, and the like can be made in this way.
Where the finest qualities of tiles or bricks are desired, the waste sand freed from
iron in the manner set forth in Patent No. 8654 of 1899 is used together with
the usual additions, ball clay, china clav, spar, stone and barvtes. These can
Ornamental slabs
of course be enamelled or coloured as in the previous case.
can also be made by placing on a flat polished surface broken refractory glass
of various colours, also flat stones and pottery which will not adhere at the heat
used. These can be placed in any pattern or arrangement and then baked with
a thick layer of glass sand and pressed into a block in the usual manner and
removed from the flat polished surface. The result will be a variegated flat
polished surface, ornamented as set forth. The sand can also be coloured to
start with and made into blocks of given thickness with vertical sides. These
blocks can be fitted together like a tessellated pavement and the whole baked
into one mass in separate blocks, a little glass sand or other more fusible material
being placed between them if desirable as a binder. Tiles made from the glass
sand with or without other materials can be coloured after having been baked
by steeping them in certain solutions and then again burning them. Thus if
they be soaked in a solution of sulphate of iron or other soluble salt of iron, and
then dried and burnt, they produce various shades of red according to the amount
of combined iron used and the temperature. Similarly nitrate of cobalt and alum
produce a blue chromate of potash or chromic acid or in fact any soluble
chromium compound will produce green. When using blocks made of our material
for polishing glass, instead of using iron dises, it will be necessary first to rough
the glass with the usual iron discs and then only use our artificial stone blocks.
If the sand used with the artificial stone blocks be kept separate from the sand
used with the iron blocks and clean sand be used in the first instance with our
blocks, the glass sand obtained is free from iron.
Having now particularly described and ascertained the nature of our said
invention, and the best mode known to us of carrying it into effect, we wish it

page_text: to be understood that we make no claim in this specification for the former
processes set forth in the preamble to this specification, but we declare that what
we claim is:
-
1. The process of making a hard tough brick from glass sand with or
without a small addition of other material described herein which consists in
pressing the damp or dry mixture into shape and heating it to the required
temperature substantially as described until the glass slightly frits and causes
the grains of sand to unite, and then slowly cooling whereby a tough annealed
brick is obtained.
2. The special processes and compositions for manufacturing white, red, blue,
hath, brindled, or other bricks or blocks, firebricks or emery or other abrasive
blocks respectively substantially as herein described.
3. The manufacture substantially as herein described of ornamental tiles, sub-
stitute for slate, marble or ceramic ware, white slabs, imitation terra cotta ware,
switch boards, ornamental or memorial tablets, or the like respectively sub-
stantially as herein described.
4. The process of colouring by means of solutions bricks or blocks made mainly
from glass sand substantially as herein described.
P 37
1000
WM. P. THOMPSON & Co.,
Patent Agents of Liverpool, Manchester, Birmingham and London.