碱金属在高炉内的反应及分配

Reaction and Distribution of Alkali Metals in Blast Furnace

为了解新配矿条件下碱金属对高炉炉料性能的影响,研究了碱金属在高炉内的反应及分配。结果表明:在高温区,碱金属硅酸盐大量分解形成碱金属蒸气随煤气上升;在中温区炉料吸附的碱金属含量为2.8%左右;在低温区约为0.3%。炉料吸附碱金属的含量随其粒度的增大而减小,炉料平均粒度从11 mm增大到17 mm时,碱金属含量从1.3%下降到0.3%。碱金属化合物对焦炭的溶损和铁矿石的还原有催化作用:当K2O含量超过1.5%时,焦炭的反应性(CRI)提高23%左右,焦炭反应后的强度(CSR)约降低40%;K2O含量增加到2.56%时,烧结矿的低温还原粉化率(RDI)约提高30%;K2O含量增加1.5%时,球团矿的RDI提高15%左右。

In order to determine the influence of alkali metals on charge properties for new burdening, the reaction and distribution of alkali metals in Blast Furnace were presented. The results show that alkali metal silicate is decomposed into alkali metal steam that rises with gas in the high temperature zone. The content of alkali metals absorbed by charge is 2. 8% in medium temperature zone, and it is about 0. 3% in the low temperature zone; it decreases with increasing the charge size when the charge size decreases from 17 mm to 11 mm and the content of alkali metals absorbed increases from 0. 3 % to 1.3 %. The alkali metals adhering to charges have a catalytic action on gasification reaction of coke; When K2O% is above 1.5, the CRI of coke will be increased by 23% and CSR will be decreased by 40%. The alkali metals also can accelerate the reduction of the iron ore. When K2O% is above 2. 56%, the RDI of sinter is increased by 30% ; When K2O% is above 1.5%, the RDI of pellet is increased by 15%.