An Improved Method of Making Cement from Chalk, Marls and Argillaceous Limestones and of Utilizing Poor Clays for the Purpose of Making Cement, and Apparatus therefor.
Year: 1889

page_text: Date of Application, 16th May, 1889
Complete Specification Left, 6th Feb., 1890-Accepted, 22nd Mar.,
1890
PROVISIONAL SPECIFICATION.
An Improved Method of Making Cement from Chalk, Marls and
Argillaceous Limestones and of Utilizing Poor Clays for the
Purpose of Making Cement, and Apparatus therefor.
I GEORGE PERCY GILDEA of 12 Warwick Road, Ipswich, in the County of Suffolk,
gentleman, do hereby declare the nature of this invention to be as follows:-
The objects are to enable Portland and the like cement of high quality to be
manufactured from chalk marls, argillaceous limestones and other natural mixtures
of carbonate of lime with silicate of alumina and iron oxide, and to render suitable for
cement making purposes clays which do not naturally possess the property of readily
combining with lime on kilning, and to provide suitable apparatus for carrying this
my invention into effect.
Marls, limestones and clays of this character exist in enormous deposits in Great
Britain and other countries, but cements hitherto made wholly or partly from them
have been found to be deficient in the qualities of setting and hardening under.water,
and do not attain any great degree of hardness in air for lengthened periods
(extending to several weeks or months) after they have been gauged.
The invention consists essentially in intermixing with the marls, limestones or clays
a small proportion of oil or fat or oily or fatty matter.
The oily or fatty matter is mixed with the marl, limestone or clay (previously
reduced by means of suitable machinery to powder or paste) thro' the agency of
water heated to boiling point.
In this intermixture I do not regard the small quantity of oily or fatty matter as
fuel, but as a chemical agent for imparting to the silicate of alumina the property of
readily combining with the line on kilning. I use any crude oil or fat whether
derived from animal, vegetable or mineral sources.
Apparatus for reducing the mineral substances to powder or paste may be horizontal,
millstones, disintegrators or mortar mills, and for mixing the oil or fat with hot water
and incorporating the oily mixture with the mineral powder or paste, agitators or
mixers may be used.
The resulting plastic mixture is then dried and calcined in the usual way.
G. P. GILDEA.
COMPLETE SPECIFICATION.
An Improved Method of Making Cement from Chalk. Marls and
Argillaceous Limestones and of Utilizing Poor Clays for the
Purpose of Making Cement, and Apparatus therefor.
1, GEORGE PERCY GULDEA of 12 Warwick Road, Ipswich, in the County of Suffolk,
Gentleman, 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 :-
My invention relates to "Portland" and other hydraulic cement and more
especially to the manufacture of cement of a superior quality from argillaceous
limestones and calcareous marls, containing carbonate of lime and combined silica
"natural".
and alumina and iron oxide in natural admixture, and commonly known as
cement rocks and marls: and to utilizing for the same purpose poor clays, that is to
ɛay, clays which, although composed mainly of a combination of silica and alumina,
nevertheless do not possess in a high degree the property of combining with lime
when mixed with and calcined along, with the latter.

page_text: Cements hitherto produced by calcining "natural" cement rocks and marls have
been found to vary considerably in quality, and moreover, when gauged or tempered
with water, to be greatly inferior to "Portland" cement in strength and in
hydraulicity, or the power of setting and hardening under water.
In the manufacture of "Portland" cement as commonly practised it- is usual to
employ carbonate of lime in the form of chalk or limestone, and hydrous silicate of
alumina in the form of clay or shale, which are disintegrated or reduced to a state of
extreme fineness and mixed together by means of any suitable apparatus with a
greater or less quantity of water: the proportions of the said inixture being
approximately three parts by weight of carbonate of lime to one part of silica and
alumina and iron oxide, or thereabouts. The mixture is then dried and calcined
under suitable conditions, and the silica and alumina enter into chemical combination
with the lime, and what is commonly known as " Portland cement is produced.
Now I have discovered that the clays and shales which are suitable for and are
commonly used in the manufacture of "Portland" or hydraulic cement of superior.
quality contain organic matter in varying proportions, but frequently to the extent of
five or six per cent. of their weight, whilst on the contrary "natural" cement rocks.
and marls (with rare exceptions) and clays which are not suitable for use in ther
manufacture of high class cements do not contain organic matter, or contain only
in minute quantities. Furthermore I have discovered by practical experiments that
by mixing a small quantity of organic matter in the form of fat or oil or fatty or oily.
matter with such cement rocks, marls, or clays as hereinafter described, and allowing
the said mixture to rest or soak for a suitable time, hydraulic or "Portland" cement;
of superior quality can be produced therefrom.
In carrying my said invention into practice I prefer to employ crude oils and fats,
such as the rough fat obtained by boiling or melting down animal substances, the coarser
oils extracted from seeds or other parts of vegetables, native rock oil, or the oil.
derived from the first distillation of oil-shale, and I use these fats and oils separately,
or any two or more of them may be mixed together. In treating the clay separately
I have found the following to be advantageous proportions, ciz.:-about four parts by.
weight of oil or fat to one hundred parts of (dry) clay. In the case of comminuted.
cement rocks or marls however, the proportion of oil or fat may be increased to about
eight or ten parts by weight to every hundred parts of clay present in the said
comminuted material, which is equivalent to using from 2 to 21 per cent. of oil or fat:
to the total quantity of raw mineral material. I have found moreover little or no:
advantage to result from exceeding this proportion of oil or fat.
12 1
I effect the thorough admixture or incorporation of the said oil or fat, or oily or
fatty matter with the comminuted or disintegrated cement rock or marl, or with the
clay, as the case may be, through the agency of hot water.
The mineral material is, if of a hard nature reduced to powder, and if of a softer
nature to paste. In the latter case water raised to a high temperature should be used
in the levigating process.
The incorporation of the fatty or oily organic matter with the comminuted or.
levigated cement rock or marl, or with the clay, is effected in a harrow-mill, or
pug-mill or mechanical mixer, or agitator of any suitable design, or by a combination
of any of these machines. I employ moreover a suitable fluid-mixer or stirrer in
which the oil or fat is rapidly agitated with water maintained as nearly as possible at
boiling point: The partial or temporary emulsion thus formed is passed quickly into
one of the above mentioned mixing machines where it is incorporated with the mineral:
powder or paste.
Sufficient hot water should be employed to make a comparatively thin and easily.
worked paste, and the mixing operation should be continued until the oil, or fat is
thoroughly diffused throughout the mass.
73
The raw mixture is then passed on to backs or reservoirs where it is permitted to,
rest or soak for about a week; the period of time will vary however according to the.
physical characteristics of the mineral material being operated upon. During this.
period of rest or soaking the affinity. possessed by the wet clay for greasy organic,

page_text: In the title of the Provisional and Complete Specifications, page 1, and in
the headings on pages 2 and 3, for
:: Chalk, marls and &c. read Chalk marls
and &c.
In the signature of the Antio

page_text: matter, and the solvent influence of the latter upon the clay come into operation. If
the treated paste is derived from cement rocks or marls, it is then pressed into bricks
or lumps (if necessary), dried, calcined and the resultant "clinker" ground to powder
by any usual and well-known means.
Clays treated in the above described manner are mixed, after the necessary period
of rest or soaking, with the proper proportion of carbonate of lime or slacked lime,
and the mixture dried, calcined, and ground to powder in a similar manner.
It will generally be found that "natural" cement rocks and marls, although
containing carbonate of lime, silica and alumina in proportions approximating more or
less to those required for the production of Portland" cement, will nevertheloss
require the addition of a certain proportion of either limestone or clay, as the case
may be, from some convenient extraneous source in order to render them entirely
suitable for serving as the raw material for manufacturing hydraulic or
"Portland
cement of a superior quality. It will in most cases be advisable to add the said
necessary proportion of extraneous limestone or clay to the cement rock or marl when
the latter is passing through the first reducing machinery.
+
Having now described and ascertained the nature of my said invention, I
wish it to be understood that I am aware that liquid hydro-carbons and other
oils or liquid combustibles have been added to cement materials to act as fuel during
the burning or calcination process, but the small quantity of oil or fat employed in my
process and in the manner and under the conditions hereinbefore set forth is intended
to act solely as a solvent and not to perform in any useful degree the office of fuel.
And I do not claim the mixing of oil or fat with the cement materials when such oil
or fat is used simply as a combustible, but I claim :-
The herein described method of utilizing oil or fat or other suitable organic matter
as a solvent in the manufacture of "Portland or other hydraulic cement.
1040
GEORGE PERCY GILDEA.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.