improvements in the manufacture of Artificial stones anu Concretes.
Year: 1885

page_text: improvements in the manufacture of Artificial stones anu
Concretes.
I ARCHIBALD CAMPBELL PONTON of Viewfield Parkstone in the County of
Dorsetshire, Architect do hereby declare the nature of my invention for IMPROVE-
MENTS IN THE MANUFACTURE OF ARTIFICIAL STONES, AND CONCRETES, to be as
follows:-
I employ one part of lime (either with or without about 40 per cent of silica)
dissolved in water or made into a fine milk of lime, to cover the superficies of the
hard particles to be used for the artificial stones, and concretes, such as for
example-sands, gravels, stones, granites, felspars, pottery, slags, or other hard
earthy or mineral substances, reduced to suitable sizes for the purpose, so that the
smaller particles fill up the voids between the larger particles. I may mix one part
of lime with as much as even one thousand parts of any of the aforesaid materials
in a fine state of division so that the lime forms a thin envelope round each particle
thus binding all the particles together in the manner exhibited by me at the
International Inventions Exhibition London 1885 under the patent form O, and
for which invention an award of a bronze medal was specified in the supplement to
the London Gazette of Tuesday the 11th day of August 1885.
To meet the requirements of economy, or convenience, I also employ one part of
lime, for less quantities, than one thousand parts, of any of the aforesaid hard
materials. For example-I employ for artificial stones, one part of lime, and about
fifty parts of a natural sand, because this sand, is economical, and abundant; and
I employ this mixture of sand, and lime, with other hard coarser materials (as
before mentioned) for making concretes, thus increasing the number of parts of the
aforesaid hard materials, from fifty parts, to one of lime, up to one hundred, or
more parts, to one of lime.
To rapidly convert all the lime, into crystallised silicate of lime, I employ for
each part of lime, (in the materials for producing the artificial stones, and concretes)
about forty per cent of silica, in crystallised silicate of soda, for intimate distribution,
amongst the aforesaid hard materials, and after the stones, and concretes, are
fabricated, I immerse them into tanks, containing hot water, along with a mere
trace of about one per cent of silicate of soda.

page_text: I employ tanks containing lime water, in which to store the fabricated articles,
until required for use.
I employ suitable ovens to dry the fabricated articles when required.
I also employ one part of chalk, with about twenty per cent silica, reduced
together to a fine milk, to form envelopes, as. before described round twenty, or
more parts, of the finer particles of the aforesaid hard materials; and I employ
kilns, to heat these finer particles, so as to produce lime from the chalk, amongst
the hard materials. I employ for each part of lime thus produced, twenty parts, or
more, of any of the aforesaid hard materials, to be mixed along with the burnt
materials, for artificial stones; and a larger number of parts, than twenty, for the
manufacture of concretes; and I employ the same processes as before described,
for rapidly crystallising all the lime, for storing, and for drying the fabricated
articles.
Deted this airteenth day of October One thousand eight hundred & eighty five

page_text: I, ARCHIBALD CAMPBELL PONTON of Viewfield Parkstone Dorset 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 :-
t
According to this Invention I use calcareous and silicious materials, either in
solution or in a finely divided state, as the materials or means, for covering the
superficies of and enveloping and binding together, the aggregates used for the
production of artificial stones and concretes, all in the manner hereinafter described,
whereby I am enabled to crystallise or bind together with one part by weight of
quick-lime for instance, a maximum of about 5000 part of impalpable powder for
the very finest grained artificial stones and of about 8000 parts when the
impalpable powder is mixed with two or three times its weight of clean sand also
for artificial stones, and as much as about 30,000 parts, when the two before
mentioned aggregates are combined together with two other descriptions of
aggregates differing very much in size, for the production of coarse concretes in
large masses. I employ limes, silicas, sands, shingle, gravels and broken or ground
stones, chalks, granites, felspars, micas, slags, clinkers, burnt clays and loams, and
flints and chalks, or other suitable earthy or mineral substances, reduced to
suitable sizes, (when so required) by breaking or grinding, and clean for making
my rock sand, artificial stones and concretes, either in castings of all descriptions,
or for constructing in situ monolithic walls, floors, and roofs, or any masses of
either artificial stone or concrete.
A. According to one mode of carrying out my invention I dissolve in cold water
one part by weight of quick-lime, so as to form a concentrated solution of the
hydrate of lime. For artificial stones of the finest grain I mix this solution with
about 5000 parts of fine powdered mineral or earthy materials of an inert character
(such for instance as burnt and ground loams) with 80 to, about 160 parts of
combined silica, and with the addition of soluble silica in such proportion, as shall
neutralise any free alkalies that may be formed in the chemical reactions taking
place by the release of the alkali in the combined silica. For artificial stones of a
coarser grain, I employ one part of quick lime dissolved in water, to mix with.
about 2000 parts of any fine inert powder combined with the same quantities of
silicas as before mentioned, to which I add, about 6000 parts of clean fine sand.
This process A is designed to give all the materials for making artificial stones,
in a powdered condition, with the exception of the lime in solution; and I may
here state, that any soluble salt of lime, such as for example, the sulphate, the
chromate, or bichromate of lime, can be used in lieu of the hydrate solution of
lime, with my processes. I sometimes mix a little sulphate of lime with the
hydrate as it is supposed to increase the hydraulicity. The amount of lime varies
according to the solubility of the particular salt of lime employed.
B. Or according to a modification I add to the limo solution, the combined and
soluble silicas, into which I may mix the before mentioned amount of aggregates,

page_text: or as a variety for the second description of artificial stone, about 2666 parts of
any fine inert powder, and 5334 parts of fine sand. This process B is designed to
give as many of the materials as possible in an aqueous solution, to mix with the
aggregates.
C. With either of the before mentioned processes, I may increase the quantity
of quick lime within certain limits, which I have discovered to be reached, when
about of a per cent of lime is used along with the other aggregates. This
process C therefore embraces all the proportions of lime, between aqueous solutions,
and one part of quick lime to 300 parts of aggregates in artificial stone made by
my process.
D. As regards process C I may change all the lime in suspension, into the
gelatinous silicate of lime first, so as to add this gelatinous silicate of lime to the
aqueous solution of lime, and silicas; thus giving rise to another method D, for
increasing the quantity of lime in solution, without diminishing (in a direct
manner) the chemical power of the quantity of silicas in process B.
E. According to another modification and for increasing the quantity of crystal-
lisible matter, I use the insoluble silicate of lime, prepared by burning together
hydrate of lime and soluble silica; or chalk, and silicate of alumina; together with
ten or more parts of any finely divided enert powder which will stand a white
heat. I then grind this insoluble silicate of lime, combined mechanically with the
inert material, into a fine impalpable powder, and I mix two or three parts by
weight of clean fine sand along with this impalpable powder and then I mix these
materials with the aqueous solution of lime, and silicas, in the proportions
mentioned in process B but it has to be noticed the artificial stones produced by
this process E, may have about 2 per cent of lime in combination amongst the total
aggregates, owing to the circumstance, of the presence of the insoluble silicate of
lime, in the finest description of aggregate employed.
F for obtaining 2 per cent of lime, or even 4 per cent, amongst the aggregates,
where a light artificial stone is required in detached pieces of small size, I employ
one part of quick lime, about half a part of soluble silica, and from 25 to 50 parts
of clean sand blended together with only pure water, and I introduce the combined-
silica subsequently while using hot sand baths, into which the fabricated articles
are introduced and through which the combined silica is allowed to infiltrate
through the artificial stones, but it is to be noted, this process F is unsuitable for
monolithic construction.
G, I employ for concretes (as is usual,) larger aggregates, in addition to those
used for artificial stone, as for example fine shingle, or clean gravel of a fine
description, for a superior concrete of a fine grained nature and for coarse concrete,
an addition may be made, as for example larger stones or broken pottery. The
proportions for concretes under processes A or B may for example, be as follows-
One part quick lime, 160 parts combined silica a trace of soluble silica (say one
part) 2000 parts of a fine inert powder, 6000 parts of a fine clean sand, 16,000 parts
of a fine shingle, or gravel, for fine grained concrete, and for coarser concrete may
be added 48,000 parts of broken stones, or pottery of a large size. These pro-
portions give the enormous (theoretical) quantity of one part of quick lime to
72,000 parts of other aggregates, as the maximum distribution of lime, but as will
be found in practice, the aqueous solution is so absorbed by the larger aggregates,
that about one part of lime, will be required to 30,000 parts of other aggregates, or
perhaps even less than that, because it must greatly depend upon the description of
the aggregates employed for the concretes.
I may here remark that I employ the usual methods of heat, and moisture to
acelerate crystallization, when the circumstances permit of my so doing, for any
one of my processes, and that I use drying rooms and ovens, and that the hot sand
baths, may be used for the means of infiltrating calcareous as well as silicious
solutions, and I also find it useful to employ tanks, for lime water, into which the
fabricated stones or concretes may be stored until required for use.
3

page_text: I use bydrate of lime as the cheapest solution of lime, although with sugar water
and lime I may obtain a solution containing about 12 times the quantity of lime.
I may also employ the sulphate, the chromate and bichromates of lime as more
soluble than the hydrate.
I make gelatinous silicate of lime with hydrate of lime in solution and ground
burnt flint, or any natural soluble silica, as the cheapest form, but it has to be
noted, gelatinous silicate of lime is also most probably formed in my processes,
whenever free lime comes into contact with a solution of silica as a preliminary
condition, towards crystallisation.
I use silica in its combination with hydro fluoride or soda, or potash, or more or
less freed from those alkalies and I also employ natural, or artificial soluble silica,
not only to prepare gelatinous silicate of lime, but also to neutralise any free
alkalies, which may arise from the chemical reactions, more especially in those
cases where an alkali may be liberated from the silica in combination, or else when
any free lime arises in solution at a subsequent period.
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:-
First: The use of calcareous, or silicious materials or both, either in solution, or
in a very finely divided state, as a means for enveloping and binding, or crystal-
lizing together stony or mineral particles, or aggregates, and thus forming my
Petrammite Artificial Stone, or Concrete substantially in the manner herein before
described.
Second-The use of gelatinous Silicate of lime combined with the calcareous and
silicious cementitious materials, so as to increase the quantity of cementitious
matter in a very fine state of division and distribution for the purpose of crystal-
lising, or binding together stony or mineral particles or aggregates, and forming
my Petrammite Artificial Stone or concrete, substantially in the manner herein-
before described.
•
Third: The use of insoluble silicate of lime, combined with a fine inert powder
to be used along with the calcareous and silicious cementitious materials, so as
to increase the amount of crystallization amongst the particles forming my
Petrammite Artificial Stone or Concrete substantially in the manner herein before
described,
Fourth-The various modes or modifications of manufacture of artificial stone
and concrete substantially in the manner herein before described.
#
1000