Coal is used
to make Coke for Iron and Steel industry. Coke is made by
baking a blend of selected Bituminious coals (called
Coking coal or Metallurgical Coal) in special high
temperature ovens without contact with air until almost
all of the volatile matter is driven off. The resulting
product, COKE, consist principally of Carbon. A short ton
of coal yeilds about 1,400 pounds of coke and a variety
of by-products such as crude coal tar, light oils, and
ammonia, which are refined to obtain various chemical
products. About 1,000 pounds of coke are consumed for
every short ton of pig iron produced.
Traditionally, chemistry, size & strength have been
considered the most important properties for use in the
blast furnace. The quality of the constituent coals
determine the charecteristicts of the resultant coke.
Coke is used chiefly to smelt iron ore and other bearing
materials in blast furnaces, acting both as a source of
heat and as a chemical reducing agent to produce pig iron
or hot metal. Coke, iron-ore and limestone are fed into
blast furnace, which runs continously. Hot air blown into
the furnace burns the coke, which serves as source of heat
and as an oxygen reducing agent to produce metallic iron.
Limestone acts as a flux and also combines with
impurities to form slag. Coke also serves as a structural
material to support the deep bed of coke/iron
oxide/limestone that makes up much of the furnace volume.
It is in this last role that its properties are crucial.
It is important that it does not degrade (e.g break up
into small particles) during its drescent through the
oxidising hot gases passing through the stock region of
the furnace.
To produce high quality blast furnace coal, high quality
coal must be used. High quality coal are those coals that
when coked together produce the highest stability and CSR (Coke strength after reactivity) to
support the blast furnace burden and allow maximum & even
maximum production.
Coke is produced and sized according to the reqirement of
each INDIVIDUAL consumer.
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