IMPROVEMENTS IN THE MANUFACTURE OF CEMENT
Year: 1878

page_text: LETTERS PATENT to Andrew Rowan, of Barnsley, in the County of York, for
the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF CEMENT.”
Sealed the 8th April 1879, and dated the 11th October 1878.
PROVISIONAL SPECIFICATION left by the said Andrew Rowan at the Office
of the Commissioners of Patents on the 11th October 1878.
ANDREW ROWAN, of Barnsley, in the County of York.
MANUFACTURE OF CEMENT."
IMPROVEMENTS IN THE
This Invention relates to the manufacture of cement from the black ash refuse or
waste of soap and other alkali manufactures.
In carrying out my Invention I first reduce the refuse or waste to a coarse
powder. I then mix it in a vessel of iron or other suitable material with dilute
sulphuric acid to the consistency of mortar, stiring it as the refuse is added until
the effervescence ceases and the mixture is neutral or slightly acid, which I ascer-
tain by means of litmus paper. The mixture is then dried on a suitable kiln, and
heated to redness. When cold it is mixed with lime, silica, peroxide of iron, or
manganese, or some similar material in such proportion as the nature of the cement
requires; and, lastly, it is ground, crushed, or otherwise reduced to a fine powder.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Andrew Rowan in the Great Seal Patent Office on the 9th April
1879.
ANDREW ROWAN, of Barnsley, in the County of York.
MANUFACTURE OF CEMENT."
"IMPROVEMENTS IN THE
The said Invention relates to the manufacture of cement from the black ash
refuse or waste of soap and other alkali manufactures, such cement being useful for
various purposes, such as blocks for building, the formation of floors, also for hydraulic
work, and other similar work.
In carrying out my Invention my first object is to get rid of the sulphur and soda
contained in the before-mentioned refuse or waste, and this I accomplish in the
following manner :-I first reduce the refuse or waste by crushing or other ordinary
means to a coarse powder. I then wash it with water, which disolves and carries
off the soda contained in it; the refuse or waste is then dried in a kiln and sub-
jected to a considerable amount of heat, say till it becomes of a dull red heat, for
the purpose of expelling the sulphur contained in it, which expulsion is afterwards
completed by a treatment of sulphuric acid. The effect of this treatment is to
convert the lime contained in the refuse or waste into sulphate of lime or gypsum.
The material is then thoroughly dried in the kiln to expel all remaining moisture,
and finally it is ground in a suitable mill in conjunction with lime, alumina, silica,
and iron, and in such proportions of either one or more of the above-mentioned
materials as may be required by the nature of the cement or the purpose for
which it is intended.
The exact proportion of the added materials cannot be giver, as the refuse is not
uniform in the composition.
The following is an approximate analysis of Portland cement :—
60-41 lime.
1-19 magnesia.
10-30 alumina.
2010 silica.
3-47 peroxide iron.
sulphuric acid.
1-
Having now described and particularly ascertained the nature of the said Inven-
tion, and the manner in which the same is or may be used or carried into effect, I
would observe in conclusion that what I consider to be novel and original and
therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is, the manufacture of cement from the black ash refuse or waste of
soap and other alkali manufactures in the manner and by the means substantially
as above described.
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