Improvements in the Manufacture of Portland Cement.
Year: 1884

page_text: Improvements in the Manufacture of Portland Cement.
I WILLIAM SMITH of 27 Waterloo Road in the City of Dublin Civil Engineer
do hereby declare the nature of my invention for IMPROVEMENTS IN THE MANU-
FACTURE OF PORTLAND CEMENT to be as follows:-
÷
I convert the Calcareous Sands which occur along parts of the Irish Coast and
which contain a larger proportion of Calcium Carbonate than is sufficient for the
manufacture of Portland Cement into Portland Cement by mixing therewith
suitable clay or other natural combination of Silica and Alumina and Iron Oxide, so
that the mixture shall contain the proper proportions of Calcium Oxide, Silica and
Alumina and Iron Oxide when calcined, which proportions I have found to be such
as shall result when calcined in a mixture containing about from sixty to sixty four
per cent of Calcium Oxide, twenty to twenty three per cent of Silica and six to
twelve per cent of Alumina and Iron Oxide: The mixture I convert into an
extremely fine powder or slip, so that the mixture shall pass through a sieve having
about two-thousand divissions to the square inch; this mixture I then make into
suitable forms either by passing through a dry press machine under great pressure,
or I dry in form of Slurry, or make into bricks or other suitable forms, and then
dry, and afterwards calcine at a high temperature, in proper kilns, with either
Coke, Coal or other fuel-After calcining I crush and finely grind the resulting
clinker, and produce the best quality of Portland Cement.
Dated this twenty fourth day of December 188four

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Portland Cement.
I WILLIAM SMITH of 27 Waterloo Road in the City of Dublin Civil Engineer
do hereby declare the nature of my invention for IMPROVEMENTS IN THE MANU-
FACTURE OF PORTLAND CEMENT and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :-
I convert the Calcareous Sands which occur along parts of the Irish Coast, and
which contain a larger proportion of Calcium Carbonate than is sufficient for the
manufacture of Portland Cement, into Portland Cement, by mixing therewith
suitable clay or shale or other natural combination of Silica Alumina and iron
oxides, so that the mixture shall contain when calcined the proper proportions of
Calcium Oxide, Silica, Alumina and iron oxides, which proportions I have found to
be such as shall result when calcined, in a mixture containing about from 60 to 64
per cent of Calcium Oxide, 20 to 23 per cent of Silica, and 6 to 12 per cent of
Alumina and Iron Oxides. The mixture I convert into an exceedingly fine powder
or slip, so that it shall pass through a sieve having about 2000 divisions to the
square inch this mixture I then make into suitable forms either by passing
through a dry press machine, or I dry in form of slurry, or make into bricks or
other forms and then dry, and afterwards calcine at a high temperature. After
calcining I crush and finely grind the resulting clinker, and produce the best
quality of Portland Cement.
Having now particularly described and ascertained the nature of my said s
Invention, and in what manner the same is to be performed, I declare that what
I claim is
The Manufacture of Portland Cement from the Calcareous Sands which occur
along the Coast of Ireland, substantially as hereinbefore described.