Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L9/00—Treating solid fuels to improve their combustion
  • C10L9/10—Treating solid fuels to improve their combustion by using additives
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B1/00—Preliminary treatment of ores or scrap
  • C22B1/14—Agglomerating; Briquetting; Binding; Granulating
  • C22B1/16—Sintering; Agglomerating

Definitions

• the invention relates to a method for reducing pollutant emissions in sintering processes in which a fuel-containing mixture, in particular a coke bed, is ignited and the pore-rich fuel fraction, in particular the coke, of the mixture rolls before the task of the fuel-containing mixture with Ca (OH) 2 or soaked in a slurry of hydrated lime.
• the known method aimed to reduce the emission of pollutants, in particular an almost complete desulphurization of the exhaust gases without expensive flue gas desulfurization, without increasing the amount of material to be handled, which is enriched with pollutants.
• the additives mentioned for the pore-rich fuel, in particular coke have a positive influence on the ignition temperature.
• the ignition temperature of the coke could be maintained almost unchanged, and when using slurries of hydrated lime, the ignition temperature of the pretreated coke could even be reduced.
• the known method in particular when using 5 to 30% by weight Ca (OH) 2, an effective desulfurization with a sulfur incorporation of over 90% was achieved. A not insignificant part of the sulfur set in this way was integrated in the finished sinter.
• Lime milk was preferably used as the basic slurry in this process, with values between 2.5 and 15 cm being proposed as the layer thickness for the grate at a bed height of the sintered mixture in order to achieve effective desulfurization. In particular with a higher layer thickness, there is a relatively large amount of sulfur-containing waste product.
• the invention now aims to improve a method of the type mentioned in such a way that with a further significant increase in sulfur incorporation and substantial reduction in SO2 emissions in the sintered exhaust gas, other pollutants, such as in particular the chlorine and fluorine emissions, in the sintered exhaust gas and NO x emissions can be significantly reduced. Furthermore, the invention aims to achieve such a reduction of the pollutants in the sintered exhaust gas with the smallest possible amounts of solid waste contaminated with pollutants.
• the invention consists essentially in that, starting from a method of the type mentioned at the outset, a grate of granular material is applied between the sintered grate and the raw mixture to be sintered, which grate has been enriched with limestone or quicklime or soaked with hydrated lime and rolled.
• the combined use of lime-treated sintered coke and lime-treated rust leads to a further reduction in SO2 emissions in the sintered exhaust gas while at the same time significantly reducing the chlorine and fluorine emissions in the sintered exhaust gas and reducing the NO x emissions by about a third.
• the improvement in exhaust gas values is achieved at the same time as a noticeable increase in performance on the sintering belt.
• impregnation with hydrated lime or roller burnishing it has surprisingly been found that a much more economical simple mixing with limestone or quicklime already brings about substantial improvements.
• the iron coating is rich in iron Minerals with a high proportion of free CaO, such as siderite or ankerite, can be used.
• the coke for the material to be sintered in an amount of 7.5 to 10 wt .-%, preferably 8.5 wt .-%, coke treated with hydrated lime, based on the material to be sintered, preferably the amount of applied Ca (OH) 2 in coke and rust coating in a ratio of 1: 1 to 4: 1, preferably 3: 1, is chosen.
• the sulfur content in the finished sinter was increased in the order of magnitude from 0.01 to up to 0.03% by weight, which has no significant disadvantages for the further use of the finished sinter.
• the amount of SO2 in the exhaust gas compared to untreated coke and untreated rust was reduced from 650 to about 350 mg / Nm3.
• a reduction of chlorine exhaust gas of 30 mg / Nm3 when using untreated coke and untreated rust to about 8 mg / Nm3 and in the case of fluorine from about 5 mg / Nm3 to 3 mg / Nm3 could be achieved.
• the NO x emission could be reduced by at least a third.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Geology (AREA)
• Geochemistry & Mineralogy (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Environmental & Geological Engineering (AREA)
• Combustion & Propulsion (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Manufacture And Refinement Of Metals (AREA)

Applications Claiming Priority (2)

Publications (2)

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Cited By (2)

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• 1991
  • 1991-06-28 AT AT129991A patent/AT395828B/de not_active IP Right Cessation
• 1992
  • 1992-06-25 EP EP19920890156 patent/EP0526446A3/de not_active Withdrawn
  • 1992-06-29 JP JP17093792A patent/JPH05179369A/ja active Pending

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