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钢铁厂产生的矿渣中很大一部分来自氧气顶吹转炉(LD转炉)和吹氧转炉工序。LD工序的主要目的是将熔融的铁水和废钢转化为优质钢。在印度,每年产生的熔融钢渣超过400~450万t。总体看来,生产每吨钢会产生150~200 kg的钢渣,对这些钢渣的处理已经成为了严重的环境问题。金达尔钢公司是年产700万t的联合钢厂,每天产生钢渣3 200 t,其中2 000~2 500 t来自LD转炉。LD转炉渣中含有47.75%的CaO,22.0%的Fe以及8.22%MgO,由于CaO含量很高,LD转炉渣可直接替代烧结工序中的生石灰。目前在实验室范围已进行了一些研究,以确定烧结工序中所允许的LD转炉渣的最大投加量以及转炉渣的投加对烧结产率和性能的影响。实验中,LD转炉渣在烧结矿里的添加量从0依次到60 kg/。t随着添加率的增大,烧结料层温度的降低致使FeO含量降低,而烧结配矿中烧损的降低以及由于避免了石灰石煅烧过程带来的的重量损失,使得烧结产率上升。与此同时,LD转炉渣中缺少自由的CaO,使烧结矿强度及还原粉化指数变差,可参加反应的CaO的减少也导致了铁酸钙相减少,及残存Fe2O3自由相增加。试验结果最终得出:烧结矿中LD转炉渣的投加量为30~35 kg/t时,可获得预期的烧结矿性能。
A large proportion of the slag produced by steel mills comes from oxygen top-blown converters (LD converters) and oxygen-blown converter processes. The main purpose of the LD process is to convert molten hot metal and scrap into quality steel. In India, more than 4 million to 4.5 million tonnes of molten slag are produced each year. Overall, 150 to 200 kg of steel slag is produced per tonne of steel produced, and handling of these steel slags has become a serious environmental problem. Jindal steel company is an annual output of 7 million tons of steel mills, steel slag produced 3 200 t, of which 2 000 ~ 2 500 t from the LD converter. The LD converter slag contains 47.75% CaO, 22.0% Fe and 8.22% MgO. Because of the high CaO content, LD converter slag can directly replace the quicklime in the sintering process. At present, a number of studies have been conducted in the laboratory to determine the maximum dosage of LD converter slag allowed in the sintering process and the effect of converter slag dosing on the sintering yield and performance. Experiment, LD converter slag in the sinter to add 0 to 60 kg /. t As the addition rate increases, the reduction of the sintering bed temperature leads to a decrease of the FeO content, whereas the reduction of the burning loss in the sintering of the ore and the increase of the sintering yield are avoided by avoiding the weight loss caused by the calcination of the limestone. At the same time, the lack of free CaO in LD converter slag leads to poor sinter strength and reducing powdering index. The decrease of CaO that can participate in the reaction also leads to the decrease of calcium ferrite phase and the increase of residual free Fe2O3 phase. The test results show that the expected sinter performance can be obtained when the dosage of LD converter slag in sinter is 30 ~ 35 kg / t.