The blast furnace is the heart of any iron production facility. Its optimal functioning ensures the well-being of the entire plant. Seven Refractories prides itself in being a blast furnace specialist. The company’s subsidiaries and teams have performed dozens of refractory projects on blast furnaces over the past years, from small and simple repairs to highly complex activities.

Each project is highly individual and unique, and Seven works with the entire palette of refractory materials and techniques. Where this is not enough, we develop new products to perfectly suit the project needs at hand. In a recent and highly complex project, Seven conducted a comprehensive repair of an entire blast furnace, involving several technical teams.


We help extend furnace life. Our customers benefit from an integrated offer of monolithic and pre-shaped products, engineering, installation, and technical support:

  • Blast furnace repair: platform, robotic
  • Runner Lining, casting, gunning, grouting, ramming
  • Manual and robotic shotcreting
  • Special projects and product development

russia_cheglov-roman_180px“Our clients in the iron industry not only appreciate the quality of our products, but also our clear service approach. We see it as our goal to perform set-up and maintenance work efficiently to decrease down time and project cost. A well-run furnace can save considerable amounts of fuel and cost.”

Roman Cheglov
Managing Director of Seven Refractories Russia


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.

Seven Refractories 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

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

Taphole clays

Seven Refractories 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.

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.

Four families of products for different requirements have been designed:

Seven Tap 100 suitable for little blast furnace
Seven Tap 200 is engineered for consistant performance in small and medium sizes blast furnaces.
Seven Tap 300 a higher content for anti-abrasives increases the taphole performance and makes it more suitable for medium and large blast furnaces.
Seven Tap 375 is the top grades of the range where the high content os SIC, Si3N4 and carbon make the products suited to extreme operating blast furnace conditions.