REFRACTORIES IN HEAT UNITS
STARTING MIXES MADE FROM DOMESTIC MATERIALS
FOR METAL CONTINUOUS CASTING
K. G. Zemlyanoi
and A. A. Kurovskii
Translated from Novye Ogneupory,No.5,pp.3–5,May2009.
Original article submitted March 4, 009.
Requirements are formulated for starting mixes for continuous metal casting. Results are provided for devel
opment of starting mix compositions made from domestic materials that satisfy the contemporary require
ments of ferrous metallurgy enterprises. Analysis of the behavior during operation of individual starting mix
components during warm up and operation is provided.
Keywords: staring mixes, steel-delivery channel, steel continuous casting, CBCM.
With a low position of the shut-off device (gate) during
pouring liquid metal fills the steel delivery channel, solidifies
within it and gives rise to a requirement for burning out the
channel with oxygen in order to open the tap to the CBCM or
with pouring from above (into a mould). Use of oxygen for
opening a tap disturbs the rhythmic work of a CBCM during
steel casting by the “melt-by-melt” method, it has a negative
effect on poured steel quality, it leads to destruction of
refractories of the slide gate, and the steel delivery assembly.
In order to exclude “blocking” of the steel delivery chan
nel it is filled with powder material during preparation of the
steel-pouring ladle for receiving the melt. Studies have made
it possible to determine the requirements laid down for
charge materials, making it possible to open a tap without us
ing oxygen. The material should have high fluidity and
looseness during heating for free emergence of it from the
steel-pouring ladle channel; a single-fraction nature and
isothermetric grain shape; inertness with respect to melt in
the ladle. In addition, the material should not have a dust
fraction (<0.063 mm), that promotes compaction and sin
Start-up of the majority of smelting units into operation
is unavoidably connected with use of a starting mix, i.e. a
charge mix preventing filling of the delivery channel with
metal and freezing of metal within it. The role of a starting
mix has increased recently in view of the more extensive use
of continuous metal pouring in CBCM. A starting mix serves
once, it is impossible to replace it, and it is not amenable to
Stopperless pouring of metal gave rise to development of
starting mix compositions. A number of examples are de-
scribed used in slide gates in the first stages, but their use did
not reach widespread application . The complexity of
structural solutions and a number of requirements, whose
fulfilment is uncontrollable, made it impossible to introduce
these developments into production. In publication  bot
tom (window) delivery of metal from an arc furnace was
considered, with which the steel-pouring channel was filled
with periclase or dunite powder of prescribed grain size com
position. The most complete basic functions and require
ments for a starting mix taking account of overseas experi
ence are provided in , within which two main require
ments are formulated: a starting mix should have high fluid
ity and looseness on heating for free flow of it from the
steel-pouring ladle channel and it should not sinter under
thermal and chemical actions of the molten metal. Thus, the
powder should exhibit good fluidity, be neutral with respect
to metal, slag and it should entirely not sinter.
The grain size composition of a starting mix is selected
taking account of formation of a finely-porous structure,
within which there should not be metal or slag. In order to
prevent mix sintering, as already noted above, it should not
contain fractions finer than 0.063 mm. Thus, currently the
following main requirements are laid down for starting
Refractories and Industrial Ceramics Vol. 50, No. 3, 2009
1083-4877/09/5003-0157 © 2009 Springer Science+Business Media, Inc.
1GOUVPO UGTU-UPI, Ekaterinburg, Russia.
OOOGranit Ekaterinburg, Russia.