SL/RN process

SL/RN Process. In the SL/RN process (Fig. 4), sized iron ore, coal, and dolomite are fed to the rotary kiln wherein the coal is gasified and the iron ore is reduced. The endothermic heat of reduction and the sensible energy that is required to heat the reactants is provided by combustion of volatiles and carbon monoxide leaving the bed with air introduced into the free space above the bed. The temperature profile in the kiln is controlled by radial air ports in the preheat zone and axial air ports in the reduction zone. Part of the coal is injected through the centerline of the kiln at the discharge end. The hot reduced iron and char is discharged into an indirect rotary dmm cooler. The cooled product is screened and magnetically separated to remove char and ash. 

The latest installations incorporate a waste heat boiler in the off-gas cleaning system to recover sensible heat from the rotary kiln off-gas. There is sufficient sensible heat in the off-gas from the SL/RN process to generate 500 to 700 kWh/t of DRJ, depending on the type of reductant used. 

Other DR Processes. The other DR processes, eg, the CODIR, DRC, ACCAR, and Dav Steel processes, make up 4.4% of worldwide production and mosdy consist of coal-based, rotary-kiln processes. Ah of these are similar to the SL/RN process. In addition, one small coal-based, shaft-furnace plant based on the Kinglor-Metor process is operating. 

Slow-wave microwave applicator structures, 16 522 SL/RN process, 24 516, 518 Sludge... 

SL/RN process -urea-formaldehyde [FORMALDEITYDE] (Vol 11) -direct reduction of iron [IRON BY DIRECT REDUCTION] (Vol 14)... 

Codir A direct reduction ironmaking process. It uses coal as the reductant in a rotary kiln. Developed by Krupp, Germany. First operated at the Dunswart plant in South Africa in 1973 two plants were operating in India in 1994. See also DR, SL/RN. 

Processes of great industrial significance Allis-Chalmers, Armco, Esso Fior, HIB, HyL, Kawasaki, Kinglor-Metor, Koho, Krupp sponge iron, MIDREX, NSC, SDR, SL/RN, SPM. 

SL/RN A DR ironmaking process, using coal as the reductant in a rotary kiln. First operated in New Zealand in 1970 and now in operation in several other countries. Six plants were in operation as of 1997. The Codir process is similar to this process. See DR. 

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