Improved Process of Manufacturing Hydraulic Cement.
Year: 1891

page_text: Date of Application, 31st July, 1891
Complete Specification Left, 2nd May, 1892-Accepted, 18th June, 1892
PROVISIONAL SPECIFICATION.
Improved Process of Manufacturing Hydraulic Cement.
I, GEORGE WILLIAMS, of Winnipeg, Canada, Gentleman, do hereby declare
the nature of this invention to be as follows:-
This my invention relates to an improved process of making hydraulic cement,
and it consists in reducing carbonate of lime to a powder by steam, under pressure,
produced from a solution of silicate of soda and water in suitable proportions,
adding to the powder so produced alumina and silex and a thin paste of chloride of
calcium, unslacked lime, and warm water, moulding it into convenient forms, which
are burned to a white heat, so as to produce a clinker, which is then ground to a
fine condition.
Dated this 31st day of July 1891
W. H. MUNNS,
Agent for Applicant.
COMPLETE SPECIFICATION.
Improved Process of Manufacturing Hydraulic Cement.
I, George Williams, of Winnipeg, Manitoba, Canada, Inventor, 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 :-
Heretofore cement has been manufactured from a composition of materials con-
taining carbonate of lime and alumina brought together by the use of water only,
and which are similar to those used by my process; but the object of my invention
is to reduce the moisture as used in the old process by a solution composed of
silicate of soda and water, acting on the materials by steam and immersion, which
produces an accurate combination of the ingredients, and by adding thereto a thin
paste of chloride of calcium, unslaked lime, and warm water with the carbonate of
lime and pulverized clay or other substances containing alumina and silex, so as to
produce a chemical reaction through the whole mass. It also reduces the heating
power required in drying and burning. It also enhances the cement produced,
both in quality and duration, and also enables me to produce hydraulic cement from
any limestone and alumina.
The process is as follows: Take carbonate of lime, or any other substance from
which lime is obtained, which on being reduced to fragments of about four-inch
cubes, being calcined in a kiln to a bright red heat, slake or fall to pieces from
exposure to the air, or from being brought into contact with water. Then put the
material into a suitable steam-tight tank, into which steam is admitted at a pressure
of not less than twenty pounds to the square inch, produced in a boiler from a
solution composed of one part of silicate of soda and one hundred parts of water, to
be increased or diminished by silicate of soda as the hardness or softness of the
material may require, the quantities here given being ordinarily sufficient, letting
it remain in the tank a sufficient length of time until the steam, acting on the
material, reduces it to a powder, and brings the whole mass to a more even degree
of tenacity; but should the carbonate of lime be used in its natural state without
being calcined, being only pulverized, then immerse the same in a suitable steam-
tight tank containing a boiling solution composed of one part of silicate of soda,
and one hundred parts of water, to be increased or diminished by silicate of soda,
as the hardness or softness of the material may require, the quantities here given
DQ17

page_text: being ordinarily sufficient, letting it remain in the tank until it becomes saturated,
which brings the whole mass to a more even degree of tenacity, the action of the
boiling solution of silicate of soda and water on the pulverized carbonate of lime
being similar to that produced by steam. The action of the steam produced by
silicate of soda and water for the steam process, and that of the boiling solution of
silicate of soda and water for the immersion process, prevents the carbonate of lime
from being oversaturated, and also combines to a greater degree with the steam,
and improves its hydraulic and insoluble properties, but steam produced from water
alone produces steam of a moist nature without the hydraulic and binding properties
of that produced by silicate of soda and water.
The boiler in which the steam is produced from the silicate of soda and water
and used for the steam process, also for the boiling solution produced from silicate
of soda and water for the immersion process is to be especially set apart for those
purposes, heated in the usual way by wood or coal, the upper portion of the boiler
having pipes to convey steam from the boiler to the tank for the steam process, and
the lower portion of the boiler to convey boiling solution for the immersion process,
both of these pipes being properly connected to the boiler and tanks in proper
positions. At this stage of the process the materials are in a condition to be taken
to the mixing-machine to be incorporated with pulverized clay or other substances
containing alumina and silex, and during the process of mixing those substances
together add a thin paste composed of chloride of calcium one part, unslaked lime
ten parts, and warm water one hundred and fifty-six parts, so that the whole will
be thoroughly saturated. incorporated, and brought to a plastic consistency, the
silicate of soda and chloride of calcium producing a chemical reaction throughout
the whole mass, the result of this being to bring it to a firmer consistency. After
this it can be moulded to any desired shape, and can then be readily handled,
afterward taken to the kiln and dried by heat so as to expel any moisture remaining,
and then burned to a state of white heat by the use of coke laid in layers between
the material, so as to produce a vitrified clinker, which, being taken to a pulverator
and ground to as fine a condition as to produce hydraulic cement ready for use, the
purposes for which it may be applied are the construction of dams, locks, piers,
water-works, foundations of all kinds, concrete cellar or other floors, foot-paths,
external finishing of houses or other buildings, and with the admixture of other
materials all the purposes for which artificial stone is used, and generally for all
purposes for which an hydraulic cement may be used.
Having now particularly described and ascertained the nature of this my said
invention, and in what manner the same is to be performed, I declare that
what I claim is :
The process of making hydraulic cement, which consists in reducing carbonate of
lime to a powder by steam, under pressure, provided from a solution of silicate of
soda and water in the proportions named, adding to the powder so produced alumina
and silex and a thin paste of chloride of calcium, unslaked lime, and warm water,
moulding it into convenient forms, which are burned to a white heat, so as to
produce a clinker, which is then ground to a fine condition, all substantially as and
for the purposes set forth.
Dhin and d of M 1900
W. H. MUNNS,
Applicant's Agent.