IMPROVEMENTS IN THE UTILIZATION OF FURNACE SLAG OR SIMILAR PRODUCTS, AND IN APPARATUS THEREFOR."
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Jasper Wetter at the Office of the
Commissioners of Patents on the 22nd June 1880. A communication from
abroad by Gustav Moysan, of Champigneulles, in the Republic of France.
JASPER WETTER, of the Firm of Herbert and Company, Solicitors of Patents, of
67, Strand, in the City of Westminster, Civil Engineer. "IMPROVEMENTS IN THE
UTILIZATION OF FURNACE SLAG OR SIMILAR PRODUCTS, AND IN APPARATUS
THEREFOR." A communication from abroad by Gustav 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 remolten 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 in 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 rectilenear grooves or conduits of the width
of a tile, and in sufficient number to retain the tiles for 40 hours or there abouts
while in continuous operation. The furnace may be built from refractory earthen
ware 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 wasto
flame may be utilized for the generation of steam, or for heating the annealing

page_text: 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 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
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.