IMPROVED PROCESS FOR THE MANUFACTURE OR PORTLAND CEMENT. AND IN APPARATUS TO BE EMPLOYED THEREIN, AND FOR
Year: 1872

page_text: LETTERS PATENT to Vitale Domenico de Michele, of Delahay Street,
in the City of Westminster, in the County of Middlesex, Civil
Engineer, for the Invention of "IMPROVED PROCESS FOR THE MANUFACTURE
OR PORTLAND CEMENT. AND IN APPARATUS TO BE EMPLOYED THEREIN, AND FOR
Sealed the 6th May 1873, and dated the 12th November 1872.
PROVISIONAL SPECIFICATION left by the said Vitale Domenico de
Michele at the Office of the. Commissioners of Patents, with his
Petition, on the 12th November 1872.
I, VITALE DOMENICO DE MICHELE, of Delahay Street, in the City of
Westminster, in the County of Middlesex, Civil Engineer, do hereby
declare the nature of the said Invention for "IMPROVED PROCESS FOR
THE MANUFACTURE OF PORTLAND CEMENT, AND IN APPARATUS TO BE EMPLOYED
THEREIN, AND FOR OTHER PURPOSES," to be as follows:-
This Invention relates to improved processes for manufacturing Port-
land cement, and to the construction and arrangement of apparatus to
be employed therein, and for other purposes.

page_text: The novelty of the first part of my Invention consists in arranging the
several appliances or apparatus necessary for the production of Portland
cement in proximity, and the passing of the material from stage to stage
automatically, thereby, firstly, dispensing with manual labour to a
greater extent than is possible under the present system; secondly, in
saving much of the time now occupied for the removal of the subsided
or precipitated particles, and in drying; and, thirdly, facilitating the
grinding of the crude cement by means of rolls. Portland cement thus
made is increased in value, the particles being more regular in size, and
uniform, and the cost of production is reduced. I take the rough or
crude chalk and clay in proper proportions, and agitate them with water,
so as to produce the required semi-liquid mixture, which is then passed
or allowed to flow into a precipitating tank of novel construction, which
tank (the second part of my Invention) may in the same manner be used
for the receipt and removal of any precipitated matters, especially chalk,
in the manufacture of whiting. In this tank for the manufacture of
Portland cement, the subsiding particles of chalk and clay, termed slip or
slurry, are allowed to precipitate or deposit themselves on an endless
band or bands working singly, or by reduplication, either on one side,
both sides, or in length, which band or bands pass through and over one
side of the tank, and the slip or slurry is by this means carried either
directly or by means of the same or other band or bands into a flue or
spent heat chamber, at the entrance of which there is a gauge, scraper, or
presser to regulate the thickness of the body carried. After the requisite
amount of moisture has been extracted the consolidated mass thus
formed is passed into a kiln to be burnt in the usual way in combination
with coke, and when sufficiently calcined it is passed between the rollers
to reduce it to a fine powder, after which it is fit for use as cement.
In lieu of burning the dried material in a kiln a reverberatory or
other furnace may be used, and in that case I dispense with the admix-
ture of coke with the dried chalk and clay.
The burning of material to form Portland cement without the direct
presence of coke is entirely new, and forms part of my Invention.
According to the third part of my Invention I dispense with the
travelling band in the tank and draw by pump, syphon, or otherwise the
slip or slurry from the bottom of the precipitating tank, and deposit it

page_text: upon an endless band or bands running within the flue or spent heat
chamber, and provided with a gauge, scraper, or presser for regulating
the supply in the manner above mentioned, or allow it to run into a
small tank of carriages having bottoms made of wire gauze or other
percolating material, or on to the bottom of the flue or spent heat
chamber itself, from whence it may be scraped, allowed to fall, or other-
wise removed. This modification is intended to be used in combination
with the other appliances for my process.
The first described form of precipitating tank with its endless band at
an angle is applicable for receiving and removing all semi-liquid bodies,
such as whiting, pigments, sugar, chemicals, sewage, and other deposits.
The details of the process are subject to such variations as are necessary
to the position or climate, or required by the quality or nature of the
materials.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Vitale Domenico de Michele in the Great Seal
Patent Office on the 12th May 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, VITALE
DOMENICO DE MICHELE, of Delahay Street, in the City of Westminster,
in the County of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of November, in the year
of our Lord One thousand eight hundred and seventy-two, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Vitale Domenico de Michele, Her special
licence that I, the said Vitale Domenico de Michele, my executors, admini-
strators, and assigns, or such others as I, the said Vitale Domenico de
Michele, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IM-
PROVED PROCESS FOR THE MANUFACTURE OF PORTLAND CEMENT, AND IN APPARATUS

page_text: ΤΟ BE EMPLOYED THEREIN, AND FOR OTHER PURPOSES," upon the condition
(amongst others) that I, the said Vitale Domenico de Michele, my exe-
cutors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said Vitale Domenico de Michele, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, reference being had to the Drawings
hereunto annexed, that is to say :-
This Invention relates to an improved process for manufacturing
Portland cement, and to the construction and arrangement of apparatus
to be employed therein, and for other purposes, the several appliances or
apparatus necessary for the production of Portland cement under my
process being placed in proximity.
The novelty of the first part of my Invention consists in withdrawing
the material as soon as possible after washing, and passing it from stage
to stage automatically, thereby, firstly, dispensing with manual labour to
a greater extent than is possible under the present system; secondly,
using considerably less fuel than heretofore; thirdly, saving much of
the time now occupied for the removal of the subsided or precipitated
particles, and in drying; and fourthly, facilitating the grinding of the
crude cement by meansof rolls. Portland cement thus made is increased
in value, the particles being more regular in size and uniform, and the cost
of production is reduced. I take the rough or crude chalk and clay in
proper proportions, and agitate them with water so as to produce the
required semi-liquid mixture, which is then passed or allowed to flow
into a precipitating tank of novel construction, which tank (the second
part of my Invention) may in the same manner be used for the receipt
and removal of any precipitated matters, especially chalk, in the
manufacture of whiting. In this tank for the manufacture of Portland
cement the subsiding particles of chalk and clay, termed slip or slurry,
are allowed to precipitate or deposit themselves on an endless band or
bands working singly or by reduplication either on one side, both

page_text: sides, or in length, which band or bands pass through and over one side
of the tank, and the slip or slurry is by this means carried either directly
or by means of the same or other band or bands into a flue or spent heat
chamber, at the entrance of which there is a gauge, scraper, or presser,
to regulate the thickness of the body carried. The wet slip enters at the
chimney or cool end of the flue, gradually passing to the hottest part,
thereby utilizing the waste heat in the most advantageous manner, and
drying the stuff uniformly. After the requisite amount of moisture has
been extracted the consolidated mass thus formed is passed into a kiln of
the usual or other construction to be burnt in the usual way in com-
bination with coke, and when sufficiently calcined it is passed between
either millstones in the usual way, orrollers to reduce it to a fine
powder, after which it is fit for use as cement.
In lieu of burning the dried material in a kiln a reverberatory or
other furnace may be used, and in that case I dispense with the
admixture of coke with the dried chalk and clay.
The burning of material to form Portland cement without the direct
presence of coke or other fuel is entirely new, and forms part of my
Invention.
According to the third part of my Invention I dispense with the
travelling band in the tank and draw by pump, syphon, or otherwise, the
slip or slurry from the bottom of the precipitating tank, and deposit it
upon an endless band or bands running within the flue or spent heat
chamber, and provided with a gauge, scraper, or presser for regulating
the supply in the manner above-mentioned, or allow it to run into a
small tank of carriages having bottoms made of wire gauze or other
percolating material. This modification is intended to be used in com-
bination with the other appliances for my process.
The first described form of precipitating tank, with its endless band at
an angle, is applicable for receiving and removing all semi-liquid bodies,
such as whiting, pigments, sugar, chemicals, sewage, and other deposits.
The details of the process are subject to such variations as are necessary
to the position or climate, or as required by the quality or nature of the
materials.
The manner of carrying my Invention practically into effect is
represented in the annexed Drawings. Figures 1 and 2 show sectional
clevation and plan views of the apparatus in its complete state for

page_text: treating the slip or slurry from the time of leaving the washing or mixing
pit to the grinding operation after the burning.
a is a trough for conveying the slip into the tank by the shoot or
spout c; this tank has an inclined false bottom d which is lower at the
slip receiving end than at the opposite end e; above this false bottom is
one portion or web of an endless belt f, and this is kept almost in contact
by a roller g, the roller being adjustable by screws h or other appliances
arranged in or to the side walls of the tank at those parts. I prefer that
this false bottom be made of some porous plastic body for water to
percolate through; below the false bottom and between it and the
bottom proper of the tank, the other web or portion of the endless
band travels, the band being kept taut and guided by rollers i, j, and k,
the latter of which is preferably the driver by which the band is moved;
the band travels in the direction of the arrows and the slip is kept
nearly level with the top of the end wall of the tank, so that the
supernatant water can be led away at that part. The precipitated body
resting upon the band is gradually removed from the water by the
onward travel of the band, its highest end roller being a few inches
above the level of the overflow wall ɩ, the slip upon the band then passes
under a gauge plate m where its surface is levelled before it enters the
fluen, there being a separate endless band p or a continuation of the
band within it for conveying the slip along to the opposite end
situated between the upper parts of two kilns, so that when the slip
arrives at that end it falls over into one or other of the shoots q, q,
Figure 2, into the kiln open to receive it. The shoots are shown double,
so that while one kiln is burning, the other is being filled, thus a
succession of burnings can be kept up; the waste heat and gases from
the burning mass in one kiln being utilized for drying the slip
preparatory to its falling into the neighbouring kiln, the end of the
flue n is so arranged that either side opening can be closed at will to
compel the draught to pass along it to the chimney or uptake r; s is a
shoot, down which coke can flow or be pushed for mixing with the slip,
so that the two bodies, slip and coke, fall together into the kiln in
the requisite proportions for the burning operation.
I propose to arrange an endless band in a flue to and between every
two kilns of a series, and to feed the slip and coke through side openings
at the upper part, the caps of the kilns having flap valves or dampers so

page_text: that should the heat be too great in the flue a portion of the heat
can be caused to escape at the top, and the dust allowed to escape.
The band in the flue is shown in the Drawing at an angle, but it
may be arranged horizontally or in other suitable manner for leading the
slip to the kiln.
Figures 3 and 4 are cross sectional views of the tank taken through
the lines and
Д
respectively.
The precipitating tank with its travelling band at an angle is an im-
portant part of my Invention, and is applicable to the precipitation of
other bodies besides cement slip, and claim is made to it for all and every
purpose it which it can be made available for precipitating and separating
solids from liquids.
In the process just described the burnt mass is when cold removed
from the kiln and ground to powder between stones, or it can be ground
between rolls such as I describe with reference to the next process, the
rolls running in pairs superposed to reduce the material gradually to fine
powder of uniform size and particles.
A precipitating tank like that previously described is employed in this
case, and the slip is carried by an endless band through a spent heat
chamber or flue to a reverberatory kind of furnace, over or in the roof
of which a boiler can be arranged for the generation of steam by which
the rolls and the band or bands can be worked. In this view the
appliances for completely operating upon the slip are shown as will be
understood by the following:-The slip from the mixing pit is pumped
up to the trough from which it flows into the tank b in which the pre-
cipitation takes place, the mass being lifted gradually to the higher level
where it becomes scraped and rendered of uniform thickness, it then
passes through the flue n, and in its travel becomes perfectly dry and
ultimately falls over the end of the band and is burnt in the furnace q,
it then runs down an incline t into and between a pair of rolls of a fixed
gauge apart; the cake is here cracked and broken sufficient to fall
between the next pair of rolls to further reduce the size of the broken
pieces; from these the material passes to other rolls in succession
until it issues in fine dust (cement powder) into a receptacle beneath.
The rolls of each pair are arranged closer together to gradually reduce

page_text: the material, and one roll of each pair or of any of them may run at
different speeds to the others for properly acting upon the body to bring
it to a fine powder. The powder (cement) is afterwards lifted from the
receptacle by buckets on an endless belt or chain from whence it falls
into a spout, to the bottom of which bags or casks are arranged for
being filled previous to being transported to their destination as desired.
By this means the whole process of Portland cement making is carried on
from the admixture of the chalk, clay, and water to the filling of the bags
or casks of the burnt and ground powder without hand labour, and in a
very short space of time, coke being dispensed with in the burning
portion of the treatment.
The last part of my Invention is shown in Figure 6, where is the
precipitating tank supplied by the nozzle c with slip from the mixing
pit. The precipitated portion is drawn from the bottom of the tank by
the pump v, and forced through the spreader y on to the endless band p
within the flue or drying chamber n, the slip having been levelled by the
scraper w in its travel. I limit the quantity drawn from the tank by
the pump by a sluice valve x at the part of the pipe between the tank
and the pump, but other arrangements can be adopted as found con-
venient. A travelling belt or other appliance may be fitted in this tank
to receive the precipitated material previous to its being drawn away
from the pump.
And having now described the nature of my said Invention and in
what manner the same is to be performed, I declare that I claim,—
-
Firstly. The method of operating upon slip or slurry from which
Portland cement is made as described, also the appliances in combina-
tion for that purpose as shown in Figures 1 and 2 of the Drawings
annexed.
Secondly. The automatic method as described with reference to
Figure 5 of the Drawings annexed, whereby Portland cement slip is
acted upon in continuous stages from and between the mixing of the
crude materials to a state of powder.
Thirdly. I claim the appliances shown in Figure 6 and their method of
action, as and for the purposes set forth.
Fourthly. I claim the construction of a tank in which an endless belt
set at an inclination is employed for the purpose of receiving and

page_text: removing the precipitants from liquid bodies as set forth, whether such
precipitants are intended for cements or for other purposes.
I also claim burning Portland cement, slip, or slurry without the direct
presence of coke, as herein-before described.
0
In witness whereof, I, the said Vitale Domenico de Michele, have
hereunto set my hand and seal, this Twelfth day of May,
One thousand eight hundred and seventy-three.
V. DE MICHELE. (L.S.)