IMPROVEMENTS IN THE MANUFACTURE OF CEMENT to be as follows:-
Year: 1884

page_text: I FREDERICK RANSOME of Lower Norwood in the County of Surrey, Civil
Engineer, do hereby declare the nature of my invention for "IMPROVEMENTS IN
THE MANUFACTURE OF CEMENT to be as follows:-
"
In the Specification of a former Patent granted to me No 4664 in the year 1878
I have described a method for the manufacture of cement by the calcination of
slag sand with chalk or other like calcarious mineral. The practice as described in
the said Specification is to grind the slag sand with the chalk and calcine them
together. I have now discovered that it is sometimes desirable to mix the lime in
a caustic or hydrated condition with the slag sand and that spent lime which has
been used in the purification of gas may be employed.
In using gas lime I find it advisable in order to get rid of the sulphur it contains
to add to the mixture of lime and slag sand a small quantity of fuel such as coal
or coke before calcining or igniting it in the furnace and during the process of
calcination or ignition I introduce a jet of steam into the furnace.
I prefer to conduct the calcination or ignition in a rotating or revolving furnace.
The mixture is admitted in the state of fine powder and is kept in motion in the
furuace. It is discharged after calcination or ignition still in the state of powder
and ready for use without further grinding. This method of burning is also
applicable to cements made from the slurry ordinarily employed as well as other
mixtures.
Dated this 18th day of April 1884

page_text: I, FREDERICK RANSOME of Lower Norwood in the County of Surrey, Civil
Engineer do hereby declare the nature of my invention for "IMPROVEMENTS IN
THE MANUFACTURE OF CEMENT" and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement
In the specification of a former Patent granted to me No 4664 in the year 1878 5
I have described a method for the manufacture of cement by the calcination of slag
sand with chalk or other like calcareous mineral. The practice as described in the
said specification is to grind the slag sand with the chalk and calcine them together.
I have now discovered that spent lime which has been used in the purification of
gas may be employed.
In using gas lime I find it advisable in order to get rid of the sulphur it contains
to add to the mixture of lime and slag sand a small quantity of fuel such as coal
coke or petroleum before calcining or igniting it in the furnace and during the
process of calcination or ignition I introduce a jet of steam into the furnace.
1
I prefer to conduct-the-calcination or ignition in a rotating or revolving furnace. 1
In manufacturing cement from slag sand and spent lime from gas-or-other works
the following proportions will generally be found suitable :-
Slag sand
Spent lime
Coal or coke
100 parts
45 to 65 "
15 to 25 "
I grind these materials together under edge runners in a mill like a mortar mill
or in other convenient manner I obtain an intimate admixture.
The materials should be used in such proportions that an analysis of the product
may show approximately,
Lime and other alkaline earth
Silica
Alumina
60 parts.
22
"
-
12
"
I then calcine the mixture by preference in a cylindrical retort or revolving
furnace set in an inclined position and revolved slowly. The retort is heated by
fuel burnt in a fire chamber at the lower end of the retort. The retort serves as a
flue to connect the fire chamber with a chimney. The mixture of materials in the
form of powder is fed continuously into the retort near the upper end by a self
acting feeder. A red heat should be maintained in the retort and matters should
be so arranged that the material in passing through the retort attains to the same
temperature which should be sufficient to insure combination of the lime and slag
Annd.
I introduce a small jet of steam into the retort at the lower end.
The cement is discharged at the lower end of the retort by an opening which is
closed against the admission of air. The cement is received into metal boxes or
receptacles and when cool is ready for use or it may be sifted by passing it through
screens of different sizes.
In some cases I may make use of the ordinary cement kiln to burn my cement.
In this case I grind the materials with a small quantity of water into a stiff mortar
which I dry and then burn in the usual way. Then after burning I grind the
cement and pass it through sieves.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declaro that what
I claim is:-
(1). The manufacture of cement from slag sand and spent limo which has been
used in the purification of gas substantially as described.
(2). The manufacture of cement by burning a mixture of slag sand spent lime
and coal or carbonaceous matter substantially as described.
(3). The manufacture of cement by burning a mixture of alag sand and spent
lime in a rotating retort substantially as described.