Cetma

Sintering technologies
Over the years, we have developed a number of innovative technologies that increase the performance and reduce the capital and operating costs. Long-term research and testing with raw materials of different origins and process parameters, coupled with continuous development and improvements in mechanical design and process automation have made us an unparalleled technologypartner. 40% of the world’s sintering Iron ore sintering has stood at the heart of the ferrous metallurgical processes for over half a century. Outotec has solid experience in agglomeration of fi ne-grained iron ores. We have built over 400 sintering plants with capacities ranging from 600 to 20,000 tons per day since 1920. Today, 40% of the world’s sinter is produced by our technology. Besidesiron ores, it can also be applied for sintering of manganese ore fines.

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Tata Iron and Steel Co., India, has already three Outotec sintering plants in operation.

Outotec sintering process
Outotec sintering process begins with the preparation of raw mix from iron ores, fl uxes, in-plant dust and spillage fi nes, solid fuel and return fi nes. These materials are mixed andgranulated in one or more stages. Water is added in order to assist the raw mix in obtaining optimum permeability for lower electricity consumption, maintained by conveying the raw mix carefully onto the sinter machine. Its surface is then ignited, air being induced through the ignited layer and sintering proceeding in the vertical direction in the sinter strand’s material bed. Subsequently, thesinter is cooled, usually in a separate sinter cooler, located at the sinter machine’s discharge outlet. The cooled sinter is crushed to a pre-determined maximum particle size. Undersized sinter that is not suitable for the blast furnace is recycled to the return fines bin. A certain quantity, usually 10–20 mm, is screened out and recirculated to the sinter machine, where it serves as a hearth layer,protecting the grate bars of the pallets during the sintering process. The product obtained from the process is a blast furnace feed of superior quality. Sintering is the agglomeration of fi ne-grained iron ores for blast furnace burden preparation. Manganese ores can also be sintered before smelting in the electric arc furnace. Sintering produces a feed of extremely consistent quality in terms ofits:
n n n n

Why sinter?

Chemical composition Grain size distribution Reducibility Sinter strength

Environmental safety
Outotec sinter plants are designed to meet the most stringent environmental regulations. For effective dust collection, electrostatic precipitators and/or bag filters dedust the sinter waste gas and air from the plant dedusting system. We provide processes for limitingdioxin, SOx and NOx emissions, while incorporating noise attenuation equipment to meet local regulations.

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EOS ® Emission optimized sintering for lower costs Iron ore sintering creates substantial off-gas volumes, and treating these in order to meet increasingly stringent environmental standards is expensive. That is why we have developed the emission optimized sinteringprocess. EOS ® uses recycling technology to reduce off-gas volumes by 40 to 50%, resulting in smaller secondary gas treatment systems. This means:
n n

Energy savings and reduced emissions What is more, CO and pollutants like SO x , NO x , dust and dioxins/furans are passed through the sinter layer together with the recirculated gas. While CO is postcombusted, substantially saving on solidfuel, the pollutants are partially retained in the sinter layer and/or thermically decomposed. In integrated steel plants about 75% of the CO 2 emissions are generated in the blast furnace and about 12% in the sintering process. When following the international CO 2 policy, the Kyoto protocol, and as there is only a minimum technical margin for CO 2 reduction measures in the blast furnace, EOS ®...