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(Coal-based DRI Plant)

Production of sponge iron by Tunnel Kiln technology was developed in 1911 as Höganäs method. Now very popular, the technology has become an effective method for sponge iron production. With the Tunnel Kiln technology, it is possible to build small plants with low investment costs.

iron & steel

The main machineries in sponge iron production through tunnel kiln technology are:

  • material handling and storage equipment;
  • magnetic separators, screens, tunnel kiln, burners, wagons;
  • SiC crucibles;
  • charging and dis-charging systems;
  • crushing and milling machines;
  • briquetting machine; and
  • iron powder reduction furnace.


  • Tunnel kiln has uniform product quality.
  • Compared to rotary kilns, production cost from tunnel kiln is lower.
  • Tunnel kiln is very low on environmental pollution.
  • It is quite comfortable with coal fines and mill scale.
  • Tunnel kiln is capable of using soft ore.


Our Research & Development department has produced sponge iron for several projects with the Tunnel Kiln technology

The department has also produced sponge iron from our 25TPD Tunnel Kiln at our steel making complex.

Based on our findings, the quality of sponge iron made by the Tunnel Kiln technology is superior compared to that produced from the rotary kilns for various reasons:

At Paras, we currently have the capacity to provide tunnel kilns up to 50, 100 and 150TPD capacity.