利用除尘灰降低铁水碳析出的实验研究

Experimental study on reducing carbon precipitation in molten iron with dust removal ash

为解决高炉到转炉转运过程中铁水的碳析出问题,采用钢铁厂含铁氧化物除尘灰作为氧化剂,并通过高温实验研究了除尘灰在降低铁水碳含量中的应用效果。考察的除尘灰有:转炉LT(Lurgi and Thyssen)除尘灰、转炉二次灰、电炉灰和高炉灰。分析了除尘灰种类、加入量、反应温度以及加料顺序对降碳效果的影响。实验研究结果表明,直接加入粉状除尘灰,氧化反应十分剧烈,并且会发生喷溅。压块后,能使除尘灰100%被利用。高炉灰碳含量过高,不能直接作为铁水降碳的氧化剂使用,其余3种灰的降碳效果依次为:转炉LT除尘灰>电炉灰>转炉二次灰。3种除尘灰加入量均为铁水质量的2%~5%时,LT除尘灰能使铁水中碳降低0.19%~0.59%,电炉灰和转炉二次灰分别为0.12%~0.47%和0.05%~0.12%。

In order to solve the problem of carbon precipitation in hot metal during the transfer process from blast furnace to converter, the dust iron containing oxide from iron and steel plant was used as oxidant, and the application effect of dust on reducing carbon content in hot metal was investigated through high-temperature experiments. The dusts under consideration included converter LT(Lurgi and Thyssen) dust, converter secondary dust, EAF(electric arc furnace) dust and blast furnace dust. The effects of dust type, addition amount, reaction temperature and feeding sequence of dust on carbon reduction were analyzed. The experimental results show that when the powdered dust is directly added into hot metal, the oxidation reaction is fairly intensive and splashing occurs. After briquetting, the dust can be utilized completely. The blast furnace dust cannot be directly used as oxidant since its carbon content is overly high. The carbon reduction effect of the other three types of dust is as follows: converter LT dust>EAF dust>converter secondary dust. When the addition amount of these three types of dust is 2%-5% of hot metal(in mass), the carbon in hot meal can be reduced by 0.19%-0.59%, 0.12%-0.47% and 0.05%-0.12%, respectively.