机械炼焦过程生成飞灰中含碳组分分布特征

Characterization of carbon contents in fly ash from coking processes

为了明确炼焦过程生成飞灰中含碳组分的污染特征,采集了山西省3座典型焦化厂的飞灰样品,利用碳元素分析仪对有机碳(OC)和元素碳(EC)组分进行测试,研究了EC/OC比值及排放因子.结果表明:炼焦飞灰中OC、EC的浓度范围分别为4.03×10~2~4.34×10~2mg/g、3.25×10~2~3.74×10~2mg/g,均值分别为4.20×10~2,3.52×10~2mg/g,飞灰中OC浓度均高于EC;不同焦化厂排放飞灰中EC/OC比值接近,范围在0.80~0.88之间,均值为0.84,煤焦化过程中EC/TC比值明显大于工业燃煤,且炼焦飞灰中EC含量高于烟气;炼焦过程OC、EC的排放因子范围分别为2970~3205g/t和2395~2756g/t,均值分别为3100,2596g/t.根据排放因子估算2016年山西省机械炼焦生成飞灰中OC、EC排放量分别为253725.1,212467.7t.

In order to clarify the characteristics of carbon contents(OC,EC) in the fly ash generated from coking process, the fly ash samples from three typical coking plants in Shanxi Province were collected. The contents of OC and EC were tested by carbon element analyzer and the EC/OC as well as emission factors were studied. The mass concentration of OC was higher than EC in fly ash. The concentration ranges of OC and EC in fly ash were 4.03×10~2~4.34×10~2 mg/g, 3.25×10~2~3.74×10~2 mg/g, with the mean values of 4.2×10~2 and 3.52×10~2 mg/g, respectively. The EC/OC in fly ash emitted from different coking plants ranged from 0.80 to 0.88 with an average of 0.84. The ratios obtained in this study are obviously higher than those from industrial coal combustion, and the EC content in fly ash is higher than that in flue gas during coking processes. Emission factors of OC and EC in coking process were 2970~3205 g/t and 2395~2756 g/t, with the mean values of 3100 and 2596 g/t, respectively. According to the emission factors, the estimated emissions of the OC and EC from fly ash during coking process in Shanxi Province in 2016 were 253725.1 and 212467.7 t, respectively.