Abstract

The effect of substituting the fossil fuel partly with gaseous fuels on CO₂ emission in sinter plants was assessed. Fuel gases such as coke oven gas (COG) and liquefied petroleum gas (LPG) were injected into the sinter pot, to see the effect on sintering speed and quality parameters. Densification was predominant in the case of COG and LPG, leading to an increase in both cold and hot strength. Acceleration of the sintering process was noticed when oxygen was injected. The various phases formed as a result of injecting COG, LPG, and oxygen were identified with the help of X-ray diffractometer (XRD). Dicalcium silicate, a detrimental phase, was found in the range of 16–25% when COG and LPG were injected and was absent when oxygen was injected. Magnetite (Fe₃O₄) and silico ferrite of calcium and aluminum (SFCA) formation got enhanced with oxygen injection. Injection of oxygen along with COG and LPG reduced dicalcium silicate and resulted in acceleration of the sintering process as well as superior quality parameters. The presence of manganese in the iron ore up to 2% resulted in MnFe₂O₄, a spinel phase that enriched the magnetite. No adverse effect of goethite was noticed due to gas injection. A reduction of 0.65 million tons in CO₂ emissions per annum was envisaged by substituting 10 kg solid fuel with gaseous fuel per ton of sinter. After successful pot tests and encouraging results therein, a COG injection system was designed and installed in an industrial-scale sinter plant.

Graphical Abstract

中文翻译：

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将液化石油气，焦炉煤气和氧气注入针铁矿烧结过程中的热力学和矿物学方面

摘要

评估了在烧结厂中用气态燃料部分替代化石燃料对CO ₂排放的影响。将诸如焦炉气（COG）和液化石油气（LPG）之类的燃料气体注入烧结罐，以观察其对烧结速度和质量参数的影响。在COG和LPG的情况下，致密化作用最为明显，导致冷强度和热强度均增加。当注入氧气时，烧结过程加速。借助X射线衍射仪（XRD）识别了由于注入COG，LPG和氧气而形成的各个相。注入COG和LPG时发现有害相的硅酸二钙在16–25％的范围内，而注入氧气时则不存在。磁铁矿（Fe ₃ O ₄）和氧注入增加了钙和铝的硅铁氧体（SFCA）的形成。与COG和LPG一起注入氧气还原了硅酸二钙，并加快了烧结过程，并提高了质量参数。铁矿石中锰含量高达2％会产生MnFe ₂ O ₄，这是一种尖晶石相，富集了磁铁矿。由于注气，未发现针铁矿的不利影响。设想通过每吨烧结矿用10千克固体燃料替换为气体燃料，每年可减少65万吨CO ₂排放。在成功进行罐测试并获得令人鼓舞的结果之后，设计并安装了COG喷射系统，并将其安装在工业规模的烧结厂中。

图形概要