Blast furnace lining engineering

The high capital investment of blast furnace relines mandates that iron makers pursue the longest possible campaign life. While the hearth remains the most critical zone for repair, the stack can always be re-profiled. Robotic repairs or manual installation by lifting platform are the usual, long experienced techniques used worldwide.

Furnace life extension is optimized by advanced engineering refractory products.

Engineering support is provided for product selection and turn key installations based on extensive international experience. The blast furnace service life extension, the environmental issues and the costs reduction are aims of an open and mutual vision.

Dalmia Seven offers a complete range of monolithic and precasted shape products suitable for any blast furnace repair.

Casthouse engineering

Casthouse performance is determined by runner and through design, product engineering and application technology. Seven’s main focus is to provide reliable high alumina and silicon corbide/carbon products for all refractory linings.

Safety lining characteristics

  • Long service life
  • No crack formations
  • Oxidation resistant
  • Iron and slag corrosion resistant
  • High mechanical properties
  • Casted on site or supplied in precasted blocks
  • Designed for zoned lining
  • Pitch-free and no toxic emission

Working lining characteristics

  • Designed for long campaign service life
  • Low, ultra-low cement and cement-free castables
  • Brown fused alumina and silicon carbide base
  • Highly erosion resistant
  • Slag resistance
  • Thermal cycling resistant
  • Low cracking behaviour
  • Pitch-free and no toxic emission

Dalmia Seven offers different lining solutions for your casthouse based on layout, installation technique, experience and user preference.


Taphole clays

Dalmia Seven taphole clay is the answer to:

  • Daily iron production of up to 12,000 t/d
  • Short intermediate tapping tap time, 20 mins
  • Long operation on the same hole, more than 20 days
  • Easy drilling at the scheduled time, no O2
  • Long stable taphole length, > 1/3 H
  • Low plugging consumption: 3 times (r*r*π*L)
  • Long cast duration, up to 200 mins
  • Low emission into the atmosphere
  • Controlled cast rate

Cast rate, corrosion resistance and balancing the taphole wear and the renewal of the “mushroom” are all aspects creating synergy between the user’s demand and the producer’s capability.

Special attention is paid to the taphole design and manufacture to ensure stable blast furnace operation and protect the hearth walls.

Dalmia Seven clays are designed for any type of mudgun. Their binding system has an improved temperature threshold preventing hardening in the mudgun barrel and cone.