AN IMPROVED METHOD OF AND APPARATUS FOR CASTING AND ANNEALING FURNACE SLAG OR وو
Year: 1875

page_text: LETTERS PATENT to Frederic Augustus Luckenbach, of the City and
State of New York, United States of America, now of No. 8, South-
ampton Buildings, London, for the Invention of "AN IMPROVED
METHOD OF AND APPARATUS FOR CASTING AND ANNEALING FURNACE SLAG OR
وو
'
PROVISIONAL SPECIFICATION left by the said Frederic Augustus
Luckenbach at the Office of the Commissioners of Patents, with
his Petition, on the 21st January 1875.
I, FREDERIC AUGUSTUS. LUCKENBACH, of the City and State of New
York, United States of America, now of No. 8, Southampton Buildings,
London, do hereby declare the nature of the said Invention for "AN
IMPROVED METHOD OF AND APPARATUS FOR CASTING AND ANNEALING FURNACE SLAG
OR CINDER," to be as follows:-

page_text: thereof, described in the specification of former Letters Patent, dated
23rd May, A.D. 1872, No. 1585.
According to my present Invention in order to cool the slag slowly in
the moulds and properly anneal it to render it tenacious and free from
the brittle and vitreous quality which ordinarily characterizes blocks
moulded from slag I employ a cooling oven of the following peculiar
construction:-The said oven is oblong or tunnel shaped, and has
successive compartments in the direction of its length, through which a
railway extends for trucks to travel on. The said compartments are
closed at the outer ends and separated from one another by movable
partitions or doors; or the movable partitions may be dispensed with and
openings made between the compartments just large enough to allow
the trucks and moulds thereon to pass through. I have found that the
moulds must be made of a material or combination of materials that not
only can withstand without injury the intense heat of the melted slag,
but which is a non-conductor of heat to a very great extent, in order to
prevent unequal cooling and irregular molecular arrangement of the slág,
material while in the moulds. For this purpose I formerly made the moulds
either of fire-clay, or of the iron furnace slag itself, or of a mixture of the two
materials, but I now make them of wrought or cast iron. These moulds
may have any desired form or shape. The aforesaid trucks which carry
the moulds have a floor of the same material or materials to form the
bottoms of the moulds placed thercon. The said moulds are arranged
side by side on the truck contiguous.to each other. There are openings
through the adjacent sides of the moulds near the bottom whereby com-
munication exists between one mould and all of the others in the set, and
the slag when poured into one of the moulds flows therefrom into all of
the other moulds, and as the moulds are thus filled at the bottom tho
gases escape freely upward at the open tops of the moulds. The mould
filling compartment of the oven having received as many trucks of
moulds as it will hold at once, and the moulds therein being filled, the
innermost truck is moved forward into the next compartment, giving
place for another truck to be introduced from the outside, and when the
latter compartment is filled with trucks transferred, from this compart-
ment the most advanced truck therein is transferred to the next com-
partment until that is filled, and if that compartment is the last in the
oven the trucks remain therein until sufficiently cooled to be withdrawn
from the oven. The cooling compartments together should hold all the

page_text: trucks of moulds filled in twenty-four hours or longer before the final
discharge of the moulds from the oven.
The new material produced by the above process may be advan-
tageously employed for many purposes. For instance, for the manu-
facture of paving and building blocks, firebricks, and other articles which
require to be of even and uniform texture and of a homogeneous
character throughout; and such articles will be refractory in a degree
hitherto unknown, and possessed of unusual hardness and consequent
capacity for resisting wear, concussion, and attrition, and the action of
fire.
My Invention comprises novel means for annealing such castings by
providing around them an external mass of molten slag, which, enclosing
the castings and slowly cooling, retards radiation of heat from the
castings, and thus insures the correspondingly slow cooling of the
castings with even and uniform contraction in all their parts, thereby
insuring their homogenity and solidity throughout.
•
My Invention further comprises the combination of one or more
moulds within a surrounding box or case, and a chamber or chambers
between for receiving the mass of molten slag externally to the moulds
simultaneously with the filling of the said moulds, whereby my aforesaid
process may be cheaply and conveniently carried into practice.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederic Augustus Luckenbach in the Great Seal
Patent Office on the 10th June 1875.
.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERIC
AUGUSTUS LUCKENBACH, of the City and State of New York, United
States of America; now of No. 8, Southampton Buildings, London, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date the Twenty-first day of January, in the year.
of our Lord One thousand eight hundred and seventy-four, in the thirty-
cighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Frederic Augustus Luckenbach, Her
special licence that I, the said Frederic Augustus Luckenbach, my execu-
.
'

page_text: tors, administrators, and assigns, or such others as I, the said Frederic
Augustus Luckenbach, 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 "AN IMPROVED METHOD OF AND APPARATUS FOR CASTING AND.
ANNEALING FURNACE SLAG OR CINDER," upon the condition (amongst others)
that I, the said Frederic Augustus Luckenbach, my executors or admini-
strators, 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 per-
formed, 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 Frederic Augustus Luckenbach, 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, reference being had to the accom-
panying Drawing forming a part of this Specification:-
My said Invention relates to the treatment of furnace slag or cinder
for the manufacture of various articles, and consists in further improve-
ments upon the Invention described in the Specification of former Letters
Patent, dated May 23rd, A.D. 1872, No. 1585.
My present Invention comprises novel means for moulding and
annealing castings of blast furnace slag by providing around them an
external mass of molten slag, which enclosing the castings of slag and
thereby slowly cooling them by retarding the radiation of the heat
within, and from them insures the correspondingly slow and uniform
contraction of the molten slag during its solidification, consequently
producing an even homogenity throughout the mass, and freedom from
flaws or fractures.
My Invention further comprises the combination of one or more
moulds placed within a surrounding enclosure or encasement, whose
purpose is to hold or contain moulds filled or to be filled with molten ;
slag, the same to remain therein during the time of its cooling or change.

page_text: The heating and cooling oven c is only required when a thin plate
iron encasements a, as shewn in Figure 2, is used to receive and
surround the moulds b, and the molten slag which surrounds them
within the said encasement. The first compartment of the said oven is
designed to gently heat the moulds 6 and encasement a to about 600 or
800° F., and when filled to assist in preventing rapid radiation of the
increased heat from the molten slag and prevent its rapid cooling during
the first stages of its solidification or contraction. This compartment is
therefore provided or connected with a furnace or other suitable means
for heating the same.
The modified encasement illustrated in Figures 6, 7, and 8, for holding
the moulds can be used to advantage when required independently of
the heating and cooling oven c above described. This modified form of
encasement may be made square, oblong, or circular, and may be con-
structed of cast or wrought iron, with or without an inside lining ƒ of
any non-conducting material, such as fire or other brick or clay, slag,
sand, or analagous substances. The said encasements a may be built or
placed upon wheeled trucks or waggons, or may be built upon a
permanent foundation, either singly or in series, attached to or detached
from each other. The said encasements a when square or oblong with`
the moulds placed thereon are arranged to be filled with molten slag
tapped from the bottom of a kettle g or ladle placed upon a railway
truck directly over them. To permit the mass of cold and solid slag in
which the moulds 6 and castings are embedded to be easily removed
from the encasement the doors or sides i of the same are supported by
hinges and arranged to rise or fall so that the mass of cooled slag will be
exposed and may be conveniently separated and removed.
In my said former Specification I have described moulds composed of
fire-brick clay, and of the furnace slag itself, to be heated to a high
temperature previous to being filled with the molten slag, and after they
were filled I depended upon the heated air of the oven in which they
were placed to prevent the molten slag in the moulds from cooling and
contracting too rapidly. I have however ascertained that the heated
moulds and heated air surrounding them could not be depended upon to
secure the desired results. But by making use of the molten slag itself
as a heating and annealing clement upon the outside of the moulds and
completely surrounding the moulds with it at the same time that the
moulds were being filled with the molten slag, as hercin described, the

page_text: heat thereof both inside and outside the moulds will be of equal tem-
perature, and as no direct radiation of the heat could take place from the
moulds thus enclosed entirely by molten slag the annealing and .
contraction of the slag during its progress of solidification will be slow
and uniform throughout the entire mass, consequently insuring with
certainty the production of castings of slag possessing the firmest, most
refractory, and homogeneous character.
The moulds may have any desired form or shape, according to the
purposes for which the slag castings are required. The said moulds aro
arranged side by side within the encasement a contiguous to each other,
and with small spaces between, as shewn in Figures 2, 6, and. 7.
There are openings through the adjacent sides of the said moulds b
near the bottom, whereby communication exists between all of the
moulds within the encasement a, and the slag when poured into one of
the moulds bor the spaces surrounding it will flow therefrom into all of
the other moulds b, and as all the moulds are thus filled simultaneously
from the bottom the gases escape freely upward to and from the open
tops of the moulds 6.
The materials best adapted for the construction of the moulds are
plate iron and cast iron. I prefer the former, as when a large number
of moulds is required they can be made cheaply thereof by being stamped
into the proper shape between prepared dies under a steam hammer.
They should be made in two or four parts or sides with fastening clips 6ª ·
to hold them in place, as shewn in Figure 4; they should be made of a
length or height to make at least three blocks, each about twelve inches
long, and in order that these blocks may be readily separated grooves or
indentations are cast around their sides at regular intervals by means of
projecting ribs 6ª formed around inside of the mould b.
The operation of casting and annealing the slag according to my
Invention is as follows:-The first or mould-filling compartment of the
oven being properly heated a truck d containing one or more thin plate-
iron encasements a, filled with the moulds b, is placed therein, and
when filled with molten slag from the ladle or kettle g placed on top of
the oven c the truck d is forced along the oven c into the next compart-
ment thereof by means of a pinion geared into a rack on the side of the
truck d, and operated by a hand wheel on the top of the oven o or by
other suitable means, thereby leaving the heating and filling compart-
'

page_text: manner.
ment c vacant for the immediate reception of another truck in a similar
The same operation may be repeated until and after all of the
cooling compartments c are filled with trucks d and moulds b. The
truck first filled is then removed into the open air again, leaving place
within the heating oven for another, and so on in continuous succession.
The ovens c should be built or arranged in pairs or in duplicate, and of
sufficient length to permit the work to be carried on continuously for
about twenty-four hours in order that the molten slag may be kept from
the action of a lower temperature than that in the cooling oven during
the first few hours.
The importance of utilising what has hitherto been a waste substance,
and which exists in great quantities, is very great, as the new material
or moulded articles produced by the above described process may be
advantageously employed for many commercial purposes; for instance,
for the manufacture of pavement blocks for streets or roadways, slabs or
flagging for side walks, gutter curbing, pipes for sewers and drains, fire-
proof deposit vaults, and for the production of many other articles used
in building and engineering work, and which require an even and
uniform surface, great strength of texture, and homogeneous character
throughout, and such articles will be refractory in a degree hitherto
unattainable, of unusual hardness and consequent capacity for resisting
wear, concussion, and attrition, and the action of great heat without
injury.
Having thus fully described my said Invention, and the manner of
performing the same, I wish it understood that I claim,-
First. In the production of castings from molten furnace slag or
cinder the application and use of liquid or molten slag for surrounding
the exterior surface of the moulds, whereby the heat of the said moulds
and the slag within the same is closely confined, and the radiation there-
from greatly retarded for the purpose of producing a uniform contraction
of the slag while it is cooling and solidifying.
Second. The encasement or enclosure with the moulds so placed
therein that spaces or chambers are left between and around them,
which enclosure, moulds, and spaces are filled with molten slag for
preventing the radiation of heat from the moulds and obtaining the slow
cooling and uniform contraction of the slag within the said moulds.
Third. The heating and graduated cooling oven, as herein described,

page_text: employed in combination with railway trucks running through the same
for conveying, heating, and cooling the encasements containing the
moulds and castings of furnace slag, as herein set forth.
Fourth. The encasements, shewn in Figures 6, 7, 8 of the Drawing,
which are constructed entirely or partly of iron, clay, brick, slag, sand,
earth, or other analagous non-conducting material, to be used singly or
in series, and either fixed or movable, so that they may be used either
with or without a heating and cooling oven, as herein set forth.
In witness whereof, I, the said Frederic Augustus Luckenbach, have
hereunto set my hand and seal, this Fifth day of April, in
the year of our Lord One thousand eight hundred and seventy-
five.
Witness,
HY. JA. NOONE.
F. A. LUCKENBACH. (L.S.).