A NEW OR IMPROVED PROCESS FOR THE MANUFACTURE OF CEMENT
Year: 1880

page_text: LETTERS PATENT to Ernest Solvay, of Brussels, in the Kingdom of Belgium,
Manufacturer, for an Invention of "A NEW OR IMPROVED PROCESS FOR THE
MANUFACTURE OF CEMENT."
PROVISIONAL SPECIFICATION left by the said Ernest Solvay at the Office
of the Commissioners of Patents on the 25th February 1880.
ERNEST SOLVAY, of Brussels, in the Kingdom of Belgium, Manufacturer.
"A NEW OR IMPROVED PROCESS FOR THE MANUFACTURE OF CEMENT."
When chloride of calcium is decomposed by a silicate of alumina, such as clay, ns
is the case when it is required to obtain chlorine or hydrochloric acid from it, the
residue is a silico-aluminate of lime. I have discovered that this residue may be
prepared so as to constitute the basis of a manufacture of cement, which is the object
of my present Invention.
The process consists of two operations, firstly, the preparation of the silico-
aluminate of lime; and, secondly, the conversion of the silico-aluminate of lime into
cement.
First Operation. It is proper first to choose for mixture with the chloride
of calcium a clay composed of the required quantities of silica and alumina, and
containing no foreign matters which might be injurious to the quality of the cement
which is to be manufactured, then the smallest quantity of the said clay necessary for
effecting the complete decomposition of the chloride of calcium is to be mixed with
the said chloride of calcium, and it is also necessary that the decomposition should
be effected at the lowest temperature possible.
Second Operation.-When a soft silico-aluminate of lime has been thus obtained,
which is readily ascertained by its being easily attacked by weak acids, I crush it
and mix it intimately with a small quantity of fine lime, calcining the said mixture
if necessary.
The cement is then constituted.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Ernest Solvay in the Great Seal Patent Office on the 11th August
1880.
ERNEST SOLVAY, of Brussels, in the Kingdom of Belgium, Manufacturer. "A
NEW OR IMPROVED PROCESS FOR THE MANUFACTURE OF CEMENT."
When chloride of calcium is decomposed by a silicate of alumina, such as clay, as
is the case when it is required to obtain chlorine or hydrochloric acid from it, the
residue is a silico-aluminate of lime.
I have discovered that this residue may be prepared so as to constitute the basis
of a manufacture of cement, which is the object of my present Invention.
The process consists of two operations :-
Firstly. The preparation of the silico-aluminate of lime; and, secondly, the
conversion of the silico-aluminate of lime into cement.
First Operation.-It is proper, firstly, to choose for mixture with the chloride
of calcium a clay composed of the required quantities of silica and alumina, and
containing no foreign matters which might be injurious to the quality of the
cement which is to be manufactured, then the smallest quantity of the said clay
necessary for effecting the complete decomposition of the chloride of calcium is to
be mixed with the said chloride of calcium, and it is also necessary that the
decomposition should be effected at the lowest temperature possible.
Second Operation.-When a soft silico-aluminate of lime has been thus obtained,
which is readily ascertained by its being easily attacked by weak acids, I crush it
and mix it intimately with a small quantity of fine line, calcining the said mixture
if necessary.
The cement is then constituted.
Having now described the nature of my said Invention and the manner of
performing the same, I claim as my said Inventiou,―
The process of manufacturing cement by the two operations herein before described,
that is to say, firstly, in the treatment of chloride of calcium by means of clay,
preparing a soft silico aluminate of lime containing no injurious substances; and,
secondly, adding lime in intimate admixture to the said soft silico-aluminate of
lime.
In witness whereof, I, the said Ernest Solvay, have hereunto set my hand
and seal, this Soventh day of August, in the year of our Lord One thousand
night hundred and sighty