(中南大学 资源加工与生物工程学院，长沙 410083)
摘 要: 不锈钢行业每年会产生大量的不锈钢尘泥，其中含有Fe、Cr、Ni等有价元素。目前不锈钢尘泥常用的处理方法如简单填埋和堆存，存在处理不完全、易产生二次污染、处理成本高等问题。本文提出了一种以球团预还原-熔炼来综合利用不锈钢酸洗污泥、除尘灰、氧化铁皮的新工艺。结果表明：不锈钢尘泥球团在预还原温度1250 ℃，预还原时间80 min，C、Fe质量比为1.5，内配炭量2%的条件下还原时，所得预还原球团抗压强度为685 N，金属化率为82.84%。该预还原球团在配焦量为8%和温度1625 ℃下熔炼20 min，得到铬铁合金中Fe、Cr、Ni含量分别为66.90%、20.28%和0.96%，回收率分别为97.62%、97.91%、96.45%。该工艺可以高效地回收不锈钢尘泥中的有价金属，获得的铬铁合金可作为200系、300系不锈钢冶炼的炉料。
关键字: 不锈钢尘泥；球团；预还原；熔炼；铬铁合金
（School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:Stainless steel, a corrosion-resistant and high-hardness material, has been widely used in chemical, medical, industrial, and other fields. However, large amounts of stainless steel dust and sludge were produced annually from the stainless steel industry, including stainless steel pickling sludge, dedusting ash, and iron oxide scale, etc. The stainless steel dust and sludge were crucial secondary resource with a high utilization value for valuable metal elements (i.e., Fe, Cr, and Ni). At present, the simple landfill and stacking treatment methods for handling stainless steel dust and sludge generally has limitations in incomplete treatment, secondary pollution, and high processing cost. Therefore, for improving the disadvantages of traditional methods, this study proposed a new process with pre-reducing and smelting to comprehensively utilize stainless steel pickling sludge, dedusting ash, and iron oxide scale. The results show that the compressive strength of pre-reduced pellets is 685N each pellet, and the metallization rate is 82.84%, under the conditions of pre-reduction temperature of 1250 ℃, pre-reduction time of 80 min, total carbon-iron mass ratio of 1.5, carbon-burdened amount of 2%. Then, the pre-reduced pellets are smelted for 20 min at coke amount of 8% and temperature of 1625 ℃. Fe, Cr, and Ni contents in the ferrochromium alloy are 66.90%, 20.28%, and 0.96%, respectively, and the corresponding recovery rates are 97.62%, 97.91%, and 96.45%, respectively. Thus, it indicates that the pellet pre-reduction-smelting process can efficiently recover valuable metals from stainless steel dust and sludge. Besides, the obtained ferrochrome alloy material can be applied in 200 series and 300 series stainless steel smelting charges. In summary, the process shows great potential to realize the resource utilization of stainless steel dust and sludge and makes feasible reference to deal with the solid waste in the stainless steel industry.
Key words: stainless steel dust and sludge; pellet; pre-reduction; smelting; ferrochromium alloy
