隧道窑工艺处理不锈钢除尘灰的实验研究

Experimental research on the tunnel kiln process for processing stainless steel dust

利用隧道窑工艺对宝钢不锈钢除尘灰进行处理.该工艺过程是将焦粉(添加量为除尘灰质量的35%)外置在除尘灰周围,并添加三种不同比例的铁鳞,在碳化硅罐中还原42 h,还原温度为1200℃.研究表明:该工艺条件能够实现不锈钢除尘灰的烧结,且通过加入铁鳞(添加量为除尘灰质量的20%)可以经济有效地提高烧结物的强度;铁鳞的加入提高了铁品位,但会降低镍、铬品位.针对金属化球团中镍、铬的金属化率难以检测出的情况,提出了一种金属还原率的估测方法,并将其应用到本实验中,得出在隧道窑工艺条件下铁和镍的金属化率分别为92.55%和97.83%,铬的金属化率最少可达到35.5%.

A tunnel kiln was used to process stainless steel dust from the Stainless Steel Branch of Baosteel. The technical process is that coke, 35% of the dust mass in dosage, was placed outside around the dust, and different proportions of iron scales were reduced in the silicon carbide tank for 42 h at 1 200 ℃. It is shown that the sintering of the dust can be realized in the tunnel kiln process and the strength of the sinter is improved economically and effectively by adding the iron scale （20% of the dust mass in dosage）. The iron grade increases by adding the iron scale, but the nickel and chromium grades decrease. A method of estimating the reduction rate was proposed since the metallization rates of nickel and chromium were difficult to be measured. This method was applied to this test, and it is found that under the condition of the tunnel kiln process, the metallization rates of iron and nickel are 92.55% and 97.83% , respectively, and the metallization rate of chromium can reach at least 35.5%.