IMPROVE- MENTS IN THE UTILIZATION OF FURNACE SLAG OR SIMILAR PRODUCTS AND IN APPARATUS THEREFOR."
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by Herbert John Haddan at the Office
of the Commissioners of Patents on the 23rd December 1879. A com-
munication from abroad by Gustave Moysan, of Champigneulles, in the
Republic of France.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. "IMPROVE-
MENTS IN THE UTILIZATION OF FURNACE SLAG OR SIMILAR PRODUCTS AND IN
APPARATUS THEREFOR." A communication from abroad by Gustave Moysan, of
Champigneulles, in the Republic of France.
The Invention has for its object the utilization of the slag or similar residuum of
blast furnaces or kilns, and consists in manufacturing from the said waste products,
tiles, bricks or analogous articles either by treating them when coming hot from the
blast furnace or after having been left to cool and re-molten in a special oven. The
process is carried out in three stages: -1. The refining of the slag when necessary
by reason of the bad quality of the slag. 2. The moulding of the articles to be
manufactured; and 3, the annealing of the same.
If the slag produced by the furnace is sufficiently malleable or in a pasty state, it
is let off from the furnace through a channel and collected on a ladle in which it is
taken to the mould, preferably of metal, to be moulded by a press analogous to that
used for the manufacture of terra cotta.
The piece is taken off the mould while red hot and treated in an annealing
furnace having rectilencar grooves or conduits of the width of a tile and in sufficient
number to retain the tiles for 40 hours or thereabouts while in continuous operation.
The furnace may be built from refractory earthenware plates and heated so as to
keep its bottom at a dull red heat, the internal pressure being somewhat stronger
than the external, so as to prevent any influx of cold air, and the products are made
to advance automatically by giving to the bottom of the furnace an inclination of
about 30 degrees. For small quantities or intermittent manufacture any ordinary
oven for annealing glass may be used instead of the special oven described. The
refining furnace may also serve for melting the slag where the latter has not been
collected from the blast furnace in a molten state, and is preferably made cylindrical
with a sheet metal casing lined internally with refractory material. The two ends
(where the flames enter and where they leave) are made smaller and the cylinder
obtains a rotary motion round its horizontal axis. The hearth or focus is placed
before the flame inlet, and the waste flame may be utilized for the generation of

page_text: steam or for heating the annealing ovens or for heating the air used for combustion.
The revolution is effected on four rollers attached to a frame mounted on wheels
which may run on rails. The cylinder having been filled with molten slag from the
blast furnace, is placed before the said hearth or focus, slowly revolved, and the
molten mass stirred or puddled, if desirable, with the addition of silicate of iron or 5
equivalent substances, and with or without suitable alcaline compounds.
For this purpose a mixture of molten slag and alkalis may be made separately
and then added to the molten slag in the oven.
After the refining process the slag is drawn off through a hole in the centre of
the oven and made to run into the ladles above described. In order to prevent any 1
sliding of the tiles when placed on the roofs their surface may be grooved or roughed,
for instance, by sand placed in the mould. Instead, of moulding the tiles under a
press they may be subjected to a press roller in a manner analogous to the rolling
of molten glass.