IMPROVE- MENTS IN CONVERTING GLASSY SLAG RESULTING FROM METALLURGICAL PROVISIONAL SPECIFICATION
Year: 1875

page_text: LETTERS PATENT to Frederick William Dahne, of Swansea, in the
County of Glamorgan, Engineer, for the Invention of "IMPROVE-
MENTS IN CONVERTING GLASSY SLAG RESULTING FROM METALLURGICAL
PROVISIONAL SPECIFICATION left by the said Frederick William
Dahne at the Office of the Commissioners of Patents, with his
Petition, on the 22nd March 1875.
I, FREDERICK WILLIAM DAHNE, of Swansea, in the County of
Glamorgan, Engineer, do hereby declare the nature of the said In-
vention for "IMPROVEMENTS IN CONVERTING GLASSY SLAG RESULTING FROM
METALURGICAL OPERATIONS FOR THE UTILIZATION THEREOF," to be as follows:-
The object of this Invention is to convert the glassy slag into a stony
or basaltic mass and cast it into any shape that may be desired. Hitherto
such glassy slag resulting from iron blast furnaces and other metallurgical

page_text: operations have been thrown away, being worthless on account of their
glassy and brittle texture.
My improvements consist in casting such slag into hot moulds,
receptacles, or vessels of any desired shape, and to keep such moulds,
receptacles, or vessels at a high temperature for about twenty-four hours,
whereby through a slow cooling process the slag in such receptacles or
vessels becomes crystalline and of a stony or basaltic texture and
therefore hard and durable for utilization.
The moulds, receptacles, or vessels I employ for this purpose consist
of a bottom plate and of sides in two parts on which is placed the top
plate or cover. Such moulds, receptacles, or vessels may of course be
made of any desired shape and might also be heated and kept at a
high temperature by various means previous to the slag being cast into
them.
By preference I adopt the following plan for heating the moulds,
receptacles, or vessels:- -I construct a trench or pit in sand or such
material as is best capable of retaining the heat. In this trench or pit
I place one or more moulds, receptacles, or vessels completely put
together on supports. I then take the slag as it comes from the furnaces
in the usual receptacles and pour it first into the trench or pit, so
as to surround and heat the moulds, receptacles, or vessels to a high
temperature before it enters the same through a hole made in the top
cover of each of same. As soon as the mould or moulds is or are filled
I cover the whole of the pit and mould or moulds with ashes or sand,
and allow the whole of the contents of the pit and moulds to cool down, 2
say, for about twenty-four hours, by which slow cooling process the slag
in the moulds looses its glassy character, taking a crystalline or basaltic
character or texture.
The sides of the pit or trench and bottom of said pit or trench may be
constructed of bricks or slag tempered by the process before described,
and as soon as such sides and bottom have by repeated use obtained a
high temperature the slag may be cast direct into such trench or pit,
thus dispensing in many cases with the moulds.
It is to be noted that a special point in my Invention is to cast into
hot moulds which by preference are heated and kept at a high temperature
the slag as before described, and allow same to cool slowly for about
twenty-four hours.

page_text: The moulds, receptacles, or vessels might be placed (instead of in a pit
or trench) in a waggon or similar construction, and such moulds,
receptacles, or vessels are then placed in said waggon on a plate and
supports, and surrounded with a moveable iron mantel. The slags would
then be allowed to run direct from the furnace into the space between
the mantel and the moulds, receptacles, or vessels, and finally into the
moulds, receptacles, or vessels, as above described.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick William Dahne in the Great Seal
Patent Office on the 22nd September 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
WILLIAM DAHINE, of Swansea, in the County of Glamorgan, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-second day of March, in
the year of our Lord One thousand eight hundred and seventy-five,
in the thirty-eighth year of Her reign, did, for Herself, Her heirs
and successors, give and grant unto me, the said Frederick William
Dahne, Her special licence that I, the said Frederick William Dahne,
my executors, administrators, and assigns, or such others as I, the
said Frederick William Dahne, 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 "IMPROVEMENTS IN CONVERTING GLASSY
SLAG RESULTING FROM METALLURGICAL OPERATIONS FOR THE UTILIZATION THEREOF,"
upon the condition (amongst others) that I, the said Frederick William
Dahne, my executors 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.

page_text: NOW KNOW YE, that I, the said Frederick William Dahne, do
hereby dclare 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:-
The object of this Invention is to convert the glassy slag into a stony
or basaltic mass and cast it into any shape that may be desired. Hitherto
such glassy slag resulting from iron blast furnaces and other metallurgical
operations have been thrown away, being worthless on account of their
glassy and brittle texture.
My improvements consist in casting such slag into hot moulds,
receptacles, or vessels, of any desired shape, and to keep such moulds,
receptacles, or vessels at a high temperature for about twenty-four hours,
whereby through a slow cooling process the slag in such receptacles or
vessels becomes crystalline and of a stony or basaltic texture, and
therefore hard and durable for utilization.
The moulds, receptacles, or vessels I employ for this purpose, consist
of a bottom plate and sides in two parts on which is placed the top
plate or cover. Such moulds, receptacles, or vessels may of course be
made of any desired shape, and might also be heated and kept at a
high temperature by various means previous to the slag being cast into
them.
By preference I adopt the following plan for heating the moulds,
receptacles, or vessels:-I construct a trench or pit in sand, or such
material that is best capable of retaining the heat. In this trench or pit
I place ono or more moulds, receptacles, or vessels, completely put
together on supports. I then take the slag as it comes from the furnaces
in the usual receptacle and pour it first into the trench or pit, so
as to surround and heat the moulds, receptacles, or vessels, to a high
temperature before it enters the same through a hole made in the top
cover of each of same. As soon as the mould or moulds is or are filled
I cover the whole of the pit and mould or moulds with ashes or sand,
and allow the whole of the contents of the pit and moulds to cool down,
say, for about twenty-four hours, by which slow cooling process the
slag in the moulds loses its glassy character, takes a crystalline or
basaltic character or texture.
The sides of the pit or trench and bottom of said pit or trench may be
1

page_text: and as soon as such sides and bottom have by repeated use obtained a
high temperature the slag may be cast direct into such trench or pit,
thus dispensing in many cases with the moulds.
It is to be noted that a special point in my Invention is to cast into
hot moulds which by preference are heated and kept at a high temperature-
the slag as before described, and allow the same to cool slowly for about
twenty-four hours.
The moulds, receptacles, or vessels, might be placed (instead of in a
pit or trench) in a waggon, or similar construction, and such moulds,
receptacles, or vessels, are then placed in said waggon on a plate and
supports, and surrounded with a movable iron mantel. The slag would'
then be allowed to run direct from the furnace into the space between
the mantel and the moulds, receptacles, or vessels, and finally into the
moulds, receptacles, or vessels, as before described.
.
Having now described the nature of the said Invention, and in what
manner the same is to be performed or carried out in practice, I will
now proceed, with the aid of the accompanying Drawings to more fully
and particularly describe and ascertain the nature and object of the said
Invention, and in what manner the same is to be performed or carried
out in practice, that is to say:—

page_text: In Fig. 5 a modified arrangement is shewn, whereby the slag is
conveyed direct from the furnace, and instead of converting it into a
stony or basaltic mass it is granulated by the aid of steam and converted
into a woolly mass. The slag issues from furnace %; thence as it comes
from the furnace a jet of steam at is directed against it, throwing the
slag through a bell mouth opening fitted to the receptacle n, into which
said receptacle it falls in a mass partaking of a woolly texture, which
may
be utilized for suitable purposes, as for instance, as a good non-
conductor for covering for steam boilers or pipes, or for water filters, and
such like.
Having now particularly described and ascertained the nature and
object of my said Invention, and in what manner the same is to be
performed or carried out in practice, I hereby declare that I claim the
Invention of "Improvements in Converting Glassy Slag resulting from
Metallurgical Operations for the Utilization thereof," substantially as the
same is herein-before set forth and described, and illustrated by the
accompanying Drawings.
In witness. whereof, I, the said Frederick William Dahne, have
hereunto set my hand and seal, this Sixteenth day of September,
in the year of our Lord One thousand eight hundred and seventy-
Live
Witness,
R. M. MопкBUTTER,
17, Somerset Place.
F. W. DÄHNE. (L.S.)