IMPROVEMENTS IN PURIFYING AND CALCINING GAS AND SOAP LIMES, AND OTHER CHEMICAL REPUSE OF LIME WHICH
Year: 1869

page_text: LETTERS PATENT to Thomas Prideaux, of Sheffield, in the County of
York, for the Invention of "IMPROVEMENTS IN PURIFYING AND CALCINING
GAS AND SOAP LIMES, AND OTHER CHEMICAL REPUSE OF LIME WHICH HAS
PROVISIONAL SPECIFICATION left by the said Thomas Prideaux at
the Office of the Commissioners of Patents, with his Petition, on
the 6th December 1869.
I, THOMAS PRIDEAUX, of Sheffield, in the County of York, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN PURIFYING
AND CALCINING GAS AND SOAP LIMES, AND OTHER CHEMICAL REFUSE OF LIME
WHICH HAS BEEN USED IN THE MANUFACTURE OF SUCH ARTICLES," to be as
follows:-
The object of this Invention is to prepare the refuse lime from the
lime purifiers of the gas works, which is known as gas lime, in such
a manner that it may be used either alone or in admixture with same,
iron scale, or other similar materials for cement, concrete, or for the
formation of blocks to be used for constructive purposes.

page_text: In order to carry out my Invention I take the gas lime and thoroughly
incorporate the substances formed by the passing of the gas through
the lime with the portion of the lime which may yet remain in the
caustic state. I accomplish this mixture by grinding the said gas lime
in a mortar mill or other suitable machine, and by preference I use the
gas lime as dry as it can be obtained, although in some cases I add
water with advantage. By this process I promote the oxidation of the
calcium sulphides and I produce a mixture which hardens in a short
time, so that the material when thus prepared can be used alone for
plaster, concrete, or cement, and also for the formation of blocks to be
used for constructive purposes. I also use a mixture of sand, or
similar material in the proportion of one-third of sand to two-thirds
of gas lime, but I do not confine myself to those proportions, and
with the said mixture I make a concrete suitable for building sea walls
or other similar constructions. I use also iron scale and colouring
matters when required for decorative purposes. By the afore-mentioned
treatment I find that the sulphides and other offensive smelling
compounds are so much oxidised that the prepared gas lime can be used
for the interior work or decoration of dwelling houses. The substance
upon hardening is quite free from unpleasant smell, and is of a light
grey colour. If the proportion of lime remaining in a caustic state be
insufficient I add a suitable quantity of quicklime when using the
prepared gas lime for the formation of blocks, or for cement, plaster, or
mortar.
Secondly. My Invention consists in submitting the gas lime prepared
in the manner herein-before described to a calcination at a regulated
temperature. This part of the Invention I perform in a suitable kiln,
which may be of the kind ordinarily used for lime burning. By this
operation I produce a material which I. pulverize and pass through a
sieve and use for forming blocks, cement, or concrete, either with or
without admixture with same, iron scale, or similar substances. The
calcined prepared gas lime is of a stone color, and when mixed with
water and used as cement or concrete it sets in a short time, forming a
very hard mass suitable for building sea walls and for other constructive
purposes.

page_text: SPECIFICATION filed in pursuance of the conditions of the Letters
Patent, and of an Order of the Lord Chancellor, by the said Thomas
Prideaux in the Great Seal Patent Office on the 10th June 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
PRIDEAUX, of Sheffield, in the County of York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of December, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
third 1 year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Thomas Prideaux, Her special licence that I,
the said Thomas Prideaux, my executors, administrators, and assigns, or
such others as I, the said Thomas Prideaux, my executors, administrators,
and assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN PURIFYING AND
CALCINING GAS AND SOAP LIMES, AND OTHER CHEMICAL REFUSE OF LIME WHICH
HAS BEEN USED IN THE MANUFACTURE OF SUCH ARTICLES," upon the condition
(amongst others) that I, the said Thomas Prideaux, my executors or
administrators, by an instrument in writing under my, or their, or one
of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to
be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas Prideaux, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement:-
The object of this Invention is to prepare the refuse lime from
purifiers of the gas works, which is known as gas lime, in such a manner
that it may be used either alone or in admixture with same, iron scale,
or other similar materials for cement, concrete, or for the formation of
blocks to be used for constructive purposes.
In order to carry out my Invention I take the gas lime and thoroughly
incorporate the substances formed by the passing of the gas through the

page_text: lime with the portion of the lime which may yet remain in the caustic
state. I accomplish this mixture by grinding the said gas lime in a
mortar mill or other suitable machine, and by preference I use the gas
lime as dry as it can be obtained, although in some cases I add water
with advantage. By this process I promote the oxidation of calcium
sulphides, and I produce a mixture which hardens in a short time so that
the material when thus prepared can be used alone for plaster, concrete, or
cement, and also for the formation of blocks to be used for constructive
purposes. I also use a mixture of sand or similar material in the
proportion of one-third of sand to two-thirds of gas lime, but I do not
confine myself to those proportions, and with the said mixture I make
a concrete suitable for building sea walls or other similar constructions.
I use also iron scale and coloring matters when required for decorative
purposes. By the afore-mentioned treatment I find that the sulphides
and other offensive compounds are so much oxidised that the prepared
gas lime can be used for the interior work or decoration of dwelling
houses. The substance upon hardening is quite free from unpleasant
smell and is of a light grey color. If the proportions of lime remaining
in a caustic state be insufficient I add a suitable quantity of quicklime
when using the prepared gas lime for the formation of blocks or for
cement, plaster, or mortar.
Secondly. My Invention consists in submitting the gas lime prepared
in the manner herein-before described to a calcination at a regulated
temperature. This part of the Invention I perform in a suitable kiln,
which may be of the kind ordinarily used for lime burning. By this
operation I produce a material which I pulverize and pass through a
sieve and use forming blocks, cement, or concrete either with or without
admixture with same, iron scale, or similar substance. The calcined
prepared gas lime is of a stone color, and when mixed with water and
used as cement or concrete it sets in a short time, forming a very hard
mass suitable for building sea walls and for other constructive purposes.
In witness whereof, I, the said Thomas Prideaux, have hereunto
set my hand and scal, this Tenth day of June, in the year of
our Lord One thousand eight hundred and seventy.
THOMAS PRIDEAUX. (L.S.)