New or Improved Substitute for Pumice Stone, and Process of Manufacturing the same.
Year: 1893

page_text: Date of Application, 10th July, 1893
Complete Specification Left, 10th Apr., 1894-Accepted, 2nd June, 1894
PROVISIONAL DIECIFICATION.
New or Improved Substitute for Pumice Stone, and Process of
Manufacturing the same.
We, HERBERT SALMON of 7 Saint Helens Terrace, Whitehouse Street, Hunslet'
Leeds in the County of York, Coach Painter and JOHN EDMUND WHITING of
Wellington Street, Leeds, aforesaid, Merchant, do hereby declare the nature of
this invention to be as follows:-
The substitute for pumice stone which we wish to protect consists of a porous
mass of silica having an insoluble or very difficultly soluble silicate binding the
grains.
The mode of manufacturing consists generally in mixing finely ground silica with
an alkaline salt, oxide or hydrate, and also with a finely comminuted organic
material, and water or other suitable volatile fluid, and pressing the same into cakes,
drying and calcining.
In carrying out our invention, we have found crushed meanwood sandstone an
excellent source of silica. This we mix with common salt, especially that quality
known as bay salt, in the proportion of 1 hundredweight of meanwood sandstone to
7 pounds of bay salt. We thoroughly dry this mixture and grind it in a mill of
chilled metal to a fine powder, and then pass it through copper gauze of 80 meshes
to the linear inch or otherwise levigate it to the required fineness. The powder is
passed through a magnetic machine, preferably electromagnetic, and all the iron
withdrawn from it by this means, such process for extracting iron being well
known. We then take one peck of soft wood sawdust, wet the sawdust to swell it,
and, when well swelled, thoroughly mix it with the before mentioned powder, and
form it into tablets by means of a press. These are then thoroughly dried and
placed in a furnace in such manner that the flame can pass round and among
them. We gently fire for the first three hours and then heat to a nearly
white heat, and, at the end of twelve hours, allow the whole to cool off, and
withdraw.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicants.
COMPLETE SPECIFICATION.
New or Improved Substitute for Pumice Stone, and Process of
Manufacturing the same.
We, HERBERT SALMON of 7 Saint Helens Terrace, Whitehouse Street, Hunslet,
Leeds in the County of York, Coach Painter and JOHN EDMUND WHITING Of
Wellington Street, Leeds aforesaid, Merchant, 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:—
The substitute for pumice stone which we wish to protect consists of a porous
mass of silica having an insoluble or very difficultly soluble silicate binding the
grains.
The mode of manufacturing consists generally in mixing finely ground silica with
an alkaline salt, oxide or hydrate, and also with a finely comminuted organic

page_text: material, and water or other suitable volatile fluid, and pressing the same into cakes,
drying and calcining.
In carrying out our invention, we have found crushed meanwood sandstone an
excellent source of silica. This we mix with common salt, especially that quality
known as bay salt, in the proportion of 1 hundred weight of meanwood sandstone to
7 pounds of bay salt. We thoroughly dry this mixture and grind it in a mill of
chilled metal to a fine powder, and then pass it through copper gauze of 80 meshes
to the linear inch or otherwise levigate it to the required fineness. The powder is
passed through a magnetic machine, preferably electromagnetic, and all the iron
withdrawn from it by this means, such process for extracting iron being well
known. We then take one peck of soft wood sawdust, (this sawdust may be
altered in quantity or entirely omitted) wet the sawdust to swell it, and, when well
swelled, thoroughly mix it with the before mentioned powder and form it into
tablets by means of a press. These are then thoroughly dried and placed in a
furnace in such manner that the flame can pass round and among them. We
gently fire for the first three hours and then heat to a nearly white heat, and, at
the end of twelve hours, allow the whole to cool off, and withdraw.
In thus describing the method of manufacture adopted by us, we do not bind
ourselves to these exact ingredients and quantities. The main requirements of the
invention being
(1) A sharp silicious sand
(2) A soluble silicate binding material
(3) A removeable material to form the interstices
(4) Means for removing this material and
(5) A method of converting the soluble silicate binding material into an
insoluble one.
Under the 1st head therefore other crushed sandstones, quartz or sharp fine sand
can be substituted. Under the 2nd head sulphate of soda or potash or even a
soluble silicate, or almost any compound of an alkali, that at the heat employed is
decomposed, or forms an insoluble silicate with a portion of the sand, will do.
Under the 3rd head almost any form of granulated organic material that will burn
out, or a salt not uniting with silica and volatile at the heat used could be
substituted, but we prefer sawdust as cheapest and best. Under the 4th head
in cases where an interstitial, soluble material, not acting on silica or the alkali, be
used, washing or dissolving out can be substituted for calcining. While under
the 5th head, especially where great heat is not used, a solution of a salt like
chloride of calcium which forms an insoluble silicate with silicate of soda could be
used, as in Ransome's stone process, and the chloride of sodium washed out, but this
again does not make as strong and useful an article as does the method we have set
forth above.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The new or improved substitute for pumice stone, consisting of a porous block
of silicious grains or particles held together by a binding of an insoluble silicate so
as to form a homogeneous but porous mass substantially as described.
2. The process of making a substitute for pumice stone substantially as described
under the five heads herein set forth or their equivalents substantially as herein
detailed.
1
ثيم
1
A
$1300
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottingham, and London, Patent Agents.