ITmk3® Process Detail
The process begins with mixing of iron ore concentrate and fine coal. The mixture is pelletized, dried, and fed to the RHF. The pellets are reduced and melted within approximately ten minutes, then discharged. The final step is separation of iron nuggets and slag. During reduction, volatiles from the coal and carbon monoxide (CO), produced from reduction, evolve into the gas space above the hearth and are combusted with air.
ITmk3® RHF Reduction Technology
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The heat thus generated, plus heat from the burners, provides the energy required for reduction and melting. The offgas from the RHF is fully combusted, but does contain considerable sensible heat. The offgas first passes through a heat recovery system to preheat combustion air, and then it goes to a gas cleaning system to remove particulates before being discharged to the atmosphere.
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Operating Parameters
While operating parameters will vary depending on the specifics of the project, the table below should be indicative of performance for a new installation.
ITmk3® Specific Consumption Figures Per Ton of Nuggets
| Iron-bearing Feed (t) | 1.5 |
| Coal (t) | 0.5 |
| Natural Gas Burner Fuel (GJ) | 4.6 |
| Electricity (kWh) | 200 |
| Water (m3) | 2.0 |
| Air (m3) | 85 |
| Nitrogen (m3) | 12 |
| Direct Labor (personnel) | 50 total |
| Maintenance ($) | 5 |
| Other ($) | 15 |
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Raw Material Parameters
For ITmk3®, the feed material is typically iron ore concentrate with the iron content 60 percent or higher for efficient performance. The figures in the table reflect general characteristics for best performance. Materials not meeting these characteristics may be acceptable, depending on economics.
Typical ITmk3® Input Characteristics
| Preferred | |
| Iron Ore Feed (Pellet Feed Grade) | |
| Total Iron | > 60% |
| SiO2 | < 8% |
| Coal | |
| Volatiles | < 30% |
| Ash/Fixed C | < 0.25 |
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Environmental Compatibility
Environmental issues are a major concern of today’s steel industry. Gaseous emissions, including SOx, NOx, CO2 and PM10 are being carefully scrutinized by government agencies and others. ITmk3® has much lower levels of these pollutants than does the blast furnace.
