IMPROVEMENTS IN THE MANUFACTURE OF CEMENT
Year: 1873

page_text: LETTERS PATENT to Henry Young Darracott Scott, of Ealing, in the
County of Middlesex, Major-General, C.B., for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF CEMENT."
Sealed the 9th June 1874, and dated the 12th December 1873.
PROVISIONAL SPECIFICATION left by the said Henry Young Darracott
Scott at the Office of the Commissioners of Patents, with his
Petition, on the 12th December 1873.
I, HENRY YOUNG DARRACOTT SCOTT, of Ealing, in the County of
Middlesex, Major-General, C. B., do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF CEMENT," to be as
follows:-
The object of this Invention is the preparation of hydraulic cement
in an economical manner.
In carrying out my Invention, I take the spent lime which has been
employed for the purification of gas, and I add thereto from 15 to 25
per cent. of ordinary clay in which the silicous ingredient preponderates..

page_text: I procure the intimate admixture of these ingredients, either by pul-
verizing them in a dry condition and thoroughly incorporating them, or
by grinding them together with water, sufficient to allow freedom of move-
ment among the particles. The resulting compound is, if the ingredients
are mixed dry formed into briquettes, with the assistance of moisture, or
if mixed wet is dried on hot floors as Portland cement is dried, and the
pieces of dried substance are calcined in kilns.
I find the cement is improved by adding to the above mixture before
calcination, from 5 to 15 per cent. of powdered coal or coke, and also by
intimately mixing with the calcined cement from 3 to 5 per cent. of
sulphate of lime or other sulphate.
In cases in which gas lime is not available, I employ in lieu thereof,
lime dust from lime works, and I either add to this lime dust from 5 to
10
per
cent. of sulphate of lime or other sulphate, and powdered coal
and coke; or I add thereto 15 to 25 per cent., more or less, of brassy
coal or powdered iron pyrites and coal, which will produce an effect
equivalent to that of the pure coal and sulphate. I also intimately mix
from 2 to 5 per cent. of finely powdered sulphate with the calcined
compound.
The use of lump lime. instead of lime dust is self evident.
In lieu also of the clay and coal, I may use pulverized peat or peat
charcoal, which will supply both the carbonaceous and argillaceous
ingredients required.
Or again, I can produce equivalent effects to those produced by the
peat by employing the deposit produced in the clarifying of sewage.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Young Darracott Scott in the Great Seal
Patent Office on the 12th June 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
YOUNG DARRACOTT SCOTT, of Ealing, in the County of Middlesex, Major- 3
General, C. B., send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of December, in the

page_text: year of our Lord One thousand eight hundred and seventy-three, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and successors;
give and grant unto me, the said Henry Young Darracott Scott, Her
special licence that I, the said Henry Young Darracott Scott, my
executors, administrators, and assigns, or such others as I, the said Henry
Young Darracott Scott, 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 THE MANUFACTURE OF CEMENT," upon the
condition (amongst others) that I, the said Henry Young Darracott
Scott, 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
Scal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Henry Young Darracott Scott, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascer-
tained in and by the following statement (that is to say) :-
The object of this Invention is the preparation of hydraulic cement in
an economical manner.
In carrying out my Invention I take the spent lime which has been
employed for the purification of gas, and I add thereto from fifteen to
twenty-five per cent. of ordinary clay in which the siliceous ingredient
preponderates. I procure the intimate admixture of these ingredients,
either by pulverizing them in a dry condition and thoroughly incor-
porating them, or by grinding them together with water, sufficient to
allow freedom of movement among the particles. I add to the above
mixture before calcination from five to fifteen per cent. of powdered coal
or coke. The resulting compound is (if the ingredients are mixed dry)
formed into briquettes with the assistance of moisture, or if mixed wet,
is dried on hot floors as Portland cement is dried, and the pieces of dried
substance are calcined in kilns. If the calcined ingredients thus pro-
duced set with too much heat, I add and intimately mix therewith, from
three to five per cent. of sulphate of lime or other sulphate.

page_text: T
In cases in which gas lime is not available, I employ in lieu thereof
lime dust from lime works, and I either add to this lime dust from five
to ten per cent. of sulphate of lime or other sulphate, and powdered coal
or coke as in the former case, unless (as is sometimes the case) much of
the unconsumed fuel remains in the compound, or I add thereto fifteen
to twenty-five per cent. more or less of brassy coal or powdered iron
pyrites and coal, which will produce an effect equivalent to that of the
pure coal and sulphate. If too much heat is generated in setting, I also
intimately mix therewith as before from two to five per cent. of finely
powdered sulphate with the calcined compound.
.
In lieu also of the clay and coal, I may use pulverized peat or peat
charcoal, which will supply both the carbonaceous and argillaceous
ingredients required..
Or again, I can produce equivalent effects to those produced by the
peat by employing the deposit produced in the clarification of sewage.
I sometimes use the gas lime and waste lime dust in combination in lieu
of using these substances separately as above mentioned.
Having now described my Invention of "Improvements in the Manu-
facture of Cement," and having explained the manner of carrying the
same into effect, I claim as the Invention secured to me by Letters
Patent as aforesaid, the use of refuse gas lime or lime dust, in com-
bination with carbonaceous and sulphur compounds for the manufacture
of cement, as herein set forth.
In witness whereof, I, the said Henry Young Darracott Scott,
have hereunto set my hand and seal, the Twelfth day of June, in
the year of our Lord One thousand eight hundred and seventy-
four.
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