IMPROVEMENTS IN THE TREATMENT OF SCORIA OR SLAG OF COPPER ORES OR SCORIA FROM OTHER ORES CONTAINING IRON IN ORDER TO EXTRACT THE IRON THEREFROM, AND IN REFINING PIG OR CAST IRON TO IMPROVE THE QUALITY OF WROUGHT OR CAST IRON
Year: 1866

page_text: ETTERS PATENT to George Crawshay, of the Firm of Hawks, Crawshay,
and Sons, Iron Works, Gateshead-on-Tyne, in the County of Durham,
and John Thomas, of Newcastle-on-Tyne, in the County of Northum-
berland, for the Invention of "IMPROVEMENTS IN THE TREATMENT OF SCORIA
OR SLAG OF COPPER ORES OR SCORIA FROM OTHER ORES CONTAINING IRON IN
ORDER TO EXTRACT THE IRON THEREFROM, AND IN REFINING PIG OR CAST IRON
TO IMPROVE THE QUALITY OF WROUGHT OR CAST IRON."
ealed the 7th May 1867, and dated the 10th November 1866.
PROVISIONAL SPECIFICATION left by the said George Crawshay and
John Thomas at the Office of the Commissioners of Patents, with their
Petition, on the 10th November 1866.
We, GEORGE CRAWSHAY, of the Firm of Hawks, Crawshay, and Sons,
Iron Works, Gateshead-on-Tyne, in the County of Durham, and JOHN
THOMAS, of Newcastle-on-Tyne, in the County of Northumberland, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE TREATMENT
OF SCORIA OR SLAG OF COPPER ORES OR SCORIA FROM OTHER ORES CONTAINING
IRON IN ORDER TO EXTRACT THE IRON THEREFROM, AND IN REFINING PIG OR CAST
IRON TO IMPROVE THE QUALITY OF WROUGHT OR CAST IRON," to be as follows:-
This Invention consists, firstly, in the treatment of scoria or slag, the residue
or waste from the manufacture of iron and from the smelting of copper ores or
scoria resulting from the smelting of any other ores. which contain iron, for the
extraction therefrom of metallic iron.

page_text: And, secondly, in the better refining of pig or cast iron generally, so as tO
produce and improve the quality of wrought or cast iron so that it shall be in
a state fit for puddling into malleable or wrought iron, or for being manu-
factured into steel, or for making iron castings of superior quality.
We proceed as follows:-We treat the slag or scoria according to the
method described in the Patent of John Thomas and Alexander Prince,
dated May 17th, 1866, No. 1403. The slags or scoria, if in too large lumps,
are to be broken, and we prefer to break them into small pieces, which may
be done by hand labour with hammers, or with a machine, or by heating the
slags red-hot and immersing them while red-hot in water, which will rend or
break the very hardest slag or scoria, and so better prepare the said slag for
future operations. When the slag or scoria is broken into a convenient size
it is ready for the operation of smelting.
-
The furnace for smelting may be of the ordinary construction used in
smelting iron ores, or any smaller size down to a common foundry cupola
furnace will perform the operation, but of course the quantity of iron produced
will be proportionate to the size of the furnace. We heat the furnace to a
high heat, such as is usual in the smelting of ores of iron, and when the
furnace is sufficiently heated we charge it with the following materials in the
usual way in which iron ores and fluxes are charged for smelting iron in the
following ratio, or thereabouts, as the quantities may be subdivided according
to the size of the furnace or the convenience of the operator, viz., one ton
of slag or scoria; one ton of pig or cast iron; four hundredweight clay, raw
or burnt; five hundredweight chalk or limestone; ten hundredweight of good
coke; if it is desirable lime may be used instead of chalk or limestone. If
the scoria operated on is of average quality, such as refinery slag, tap cinder,
or mill cinder, or any of the scoria produced from the manufacture of iron,
the product from the smelting of the above quantities would be one ton and
ten hundredweight (1 ton 10 cwts.) of good iron, and in the general way will
need no further operation preparatory to puddling into malleable or wrought
iron. Thus by the aid of pig or cast iron and clay we extract from the slag
or scoria about fifty per cent. of metallic iron; but we do not limit ourselves
to the use of the quantities named (only), but we intend to claim to use them
in any proportion that we may require, so as to produce iron if needed of
different qualities.
We have made an excellent wrought iron from the following quantities in
proportions of slag and cast iron, namely, eight hundredweight of pig iron and
twenty hundredweight of slag or scoria smelted with a proper proportion of the
fluxes named, and have produced eighteen hundredweight, three quarters, four-

page_text: teen pounds of refined iron, and the bolt iron from the puddled bar was of
excellent quality, and stood a high test. When the iron from slag or scoria
contains those elements which produce when puddled into malleable iron, red
short or cold short iron, or both red and cold short, we then melt it again in
a similar blast furnace or cupola, with what we term our refining flux, and
this furnace is what may be termed the melting refinery; and in this furnace
we also refine pig or cast iron so as to prepare it for the operation of puddling
into malleable iron; this melting refinery we also heat, as before described,
for smelting slag or scoria, and when sufficiently heated we charge the furnace
with the following quantities of materials, but which quantities may be sub-
divided or re-arranged according to the magnitude of the furnace or according
to the quality of the materials to be named, as follows:-One ton of pig or.
cast iron, three hundredweight of clay; six hundredweight of cinder or scoria
from previous smelting, the glassy cinder preferred, and some wrought-iron
scraps which may be varied in quantity according to the quality of iron
required; but from two to five hundredweight of wrought scraps according to
the quality of cast iron would produce a good result, and to smelt this quantity.
five hundredweight of good coke would be sufficient, but even these quantities
must be subject to the qualities of the several ingredients, and be arranged
accordingly. In this refining process the iron and fluxes are charged in the usual.
way adopted for smelting iron. The tap hole is stopped so as to form a bath of:
flux; when the iron melts it gravitates to and percolates through the flux in
a divided state, and is in consequence cleansed of many of its impurities.
A test of our process may be made in any works, and with the
material in the neighbourhood of such works, firstly, by a crucible, which
crucible should be of plumbago, and afterwards by a small cupola, which
with a few experiments will give the proper quantities to produce good
iron from almost any of such materials as we have named. When we smelt
or refine iron for the purpose of converting it into malleable or wrought iron.
we prefer to run it out of the furnace into iron moulds or chills, but if the
iron is to be used for casting purposes, we then prefer to run it out into sand
moulds or pigs.
We have now described our Invention, and the manner in which it is to
be carried into effect, namely, by the smelting of slag or scoria with pig or
cast iron in combination with clay for our flux and lime or limestone so as to
extract the iron from such scoria or cinder, and for the better refining such
iron, omitting the lime or limestone if desirable, thereby shewing that. as iron
in smelting with lime fluxes will take up lime in its composition, and that
such lime greatly. deteriorates the iron, so will pig or cast iron by being

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Crawshay and John Thomas in the Great Seal Patent
Office on the 10th May 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, GEORGE
CRAWSHAY, of the Firm of Hawks, Crawshay, and Sons, Iron Works,
Gateshead-on-Tyne, in the County of Durham, and JOHN THOMAS, of New-
castle-on-Tyne, in the County of Northumberland, send greeting....
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of November, in the year of our Lord
One thousand eight hundred and sixty-six, in the thirtieth year of Her reign,.
did, for Herself, Her heirs and successors, give and grant unto us; the said
George Crawshay and John Thomas, Her special licence that we, the said
George Crawshay and John Thomas, our executors, administrators, and
assigns, or such others as we, the said George Crawshay and John Thomas,
our 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 THE
TREATMENT OF SCORIA OR SLAG OF COPPER ORES OR SCORIA FROM OTHER.ORES
CONTAINING IRON IN ORDER TO EXTRACT THE IRON THEREFROM, AND IN REFINING
PIG OR CAST IRON TO IMPROVE THE QUALITY OF WROUGHT OR CAST IRON," upon
the condition (amongst others) that we, the said George Crawshay and
John Thomas, our executors or administrators, by an instrument in writing.
under our, 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 George Crawshay, do hereby declare.
the nature of our said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
This Invention consists, firstly, in the treatment of scoria or slag, the residue.

page_text: or waste from the manufacture of iron and from the smelting of copper ores
or scoria resulting from the smelting of any other ores which contain iron for
the extraction therefrom of metallic iron.
And, secondly, in the better refining of pig or cast iron generally so as to
produce and improve the quality of wrought or cast iron, so that it.shall be
in a state fit for puddling into malleable or wrought iron, or for being manu-
factured into steel, or for making iron castings of superior quality...
We proceed as follows:-We treat the slag or scoria according to the
method described in the Patent of John Thomas and Alexander Prince, dated
May 17th, 1866, No. 1403. The slags or scoria if in too. large lumps are to:
be broken, and we prefer to break them into small pieces, which may. be
done by hand labor with hammers, or with a machine, .or by heating the
slags red-hot and immersing them while red-hot in water, which will. rend.or
break the very hardest, slag or scoria, and so better prepare the said 'slag for:
future operations. When the slag or scoria is broken into a convenient size
it is ready for the operation of smelting.
The furnace for smelting may be of the ordinary construction used in
smelting iron ores, or any smaller size down to a common foundry cupola
furnace will perform the operation, but of course the quantity of iron
produced will be proportionate to the. size of the furnace. We heat the
furnace to a high heat, such as is usual in the smelting of. ores of iron, and
when the furnace is sufficiently heated we charge it with the following:
materials in the usual way in which iron ores and fluxes are charged for
smelting iron in the following ratio, or thereabouts, as the quantities. may be
subdivided according to the size of the furnace or the convenience of the
operator, viz., one ton of slag or scoria; one ton of pig or cast iron; four
hundredweight of clay, raw or burnt; five hundredweight of chalk or lime-
stone; ten hundredweight of good coke. If it is desirable lime may be used:
instead of chalk or limestone. If the scoria operated on is of average quality,
such as refinery slag, tap cinder, or mill cinder, or any of the scoria produced'
from the manufacture of iron, the product from the smelting of the above.
quantities would be one ton and ten hundredweights (ton 1, cwt. 10,) of good.
iron, and in. the general way will need no further operation preparatory to.
puddling into malleable or wrought iron. Thus by the aid of pig or cast iron,
and clay we extract from the slag or scoria about fifty per cent. of metallic
iron, but we do not limit ourselves to the use of the quantities-named (only),
but we claim to use them in any proportion that we may require so as. to.
produce iron if needed of different.qualities.
"
. We have made an excellent wrought-iron from the following quantities or

page_text: proportions of slag and cast iron, namely, eight hundredweight of pig iron,
and twenty hundredweight of slag or scoria smelted with a proper proportion
of the fluxes named, and have produced cwt. 18, qrs. 3, lbs. 14 of refined iron,
and the bolt iron from the puddled bar was of excellent quality, and stood a
high test. When the iron from slag or scoria contains those elements which
produce when puddled into malleable iron red short or cold short iron, or
both red and. cold short, we then melt it again in a similar blast furnace or
cupola with what we term our refining flux, and this furnace is what may be
termed. the melting refinery, and in this furnace we also refine pig or cast iron
so as to prepare it for the operation of puddling into malleable iron; this
melting refinery we also heat as before described. for smelting slag or scoria,
and when sufficiently heated we charge the furnace with the following
quantities of materials, but which quantities may be subdivided or re
arranged .according to the magnitude of the furnace, or according to the
quality of the materials to be named:-One ton of pig or cast iron, three
hundredweight of clay, six hundredweight of cinder or scoria from previous
smelting (the glassy cinder preferred), and some wrought-iron scraps, which
may be varied in quantity according to the quality of iron required; but from
two to five hundredweight of wrought scraps according to the quality of cast
iron would produce a good result, and to smelt this quantity five hundred-
weight of good coke would be sufficient, but even these quantities must be
subject to the qualities of the several ingredients and be arranged accordingly.
In this refining process the iron and fluxes are charged in the usual way
adopted for smelting iron. The tap hole is stopped so as to form a bath of
flux; when the iron melts it gravitates to and percolates through the flux in a
divided state, and is in consequence cleansed of many of its impurities. A
test of our process may be made in any works, and with the materials in the.
neighbourhood of such works; firstly, by a crucible, which crucible should be
of plumbago, and afterwards by a small cupola, which with a few experiments
will give the proper quantities to produce good iron from almost any of such
materials as we have named. When we smelt or refine iron for the purpose
of converting it into malleable or wrought iron we prefer to run it out of
the furnace into iron moulds or chills; but if the iron is to be used for casting
purposes, we then prefer to run it out into sand moulds or pigs.
We have now described our Invention and the manner in which it is to be
carried into effect, namely, by the smelting of slag or scoria with pig or cast.
iron in combination with clay for our flux, and lime or limestone, so as to
extract the iron from such cinder or slag, and for the better refining such iron
omitting the lime or limestone if desirable, thereby shewing that as iron in

page_text: smelting with lime fluxes will take up lime in its composition, and that such
lime greatly deteriorates the iron, so will pig or cast iron by being melted
again in the clay flux without lime be deprived of its lime, and will take up
in its stead a portion of aluminium.
3 We claim the "Improvements in the Treatment of Scoria or Slag of Copper
Ores or Scoria from other Ores containing Iron in order to Extract the Iron
therefrom, and in Refining Pig or Cast Iron to Improve the Quality of
Wrought or Cast Iron," substantially as herein specified.
In witness whereof, I, the said George Crawshay, have hereunto set my
hand and seal, this Third day of May, in the year of our Lord One
thousand eight hundred and sixty-seven.
Witness,
ALEX. C. M. PRINCE,
Office for Patents,
4, Trafalgar Square,
Charing Cross.
GEORGE CRAWSHAY. (L.s.)