Pollution characteristics of residues from coal coking process

In order to reduce residue from coal coking,tar,tar slag,coke powder,precipitator dust Ⅰ and Ⅱ were as test objects. Two different leaching solutions were obtained from five residues using sulfuric and nitric acid method and horizontal vibration method respectively. These leaching solutions were tested for the 13 heavy metal ion concentrations using inductive coupling plasma emission spectrograph.Meanwhile,16 prior pollutants of all PAHs,listed by US EPA,from residues were analyzed through ultrasonic extraction and GC- MS. The composition of PAHs,different ring distribution of PAHs and ∑BEQ were investigated. The results showed that,only Cr6 +was not detected,the other 12 heavy metal ion concentrations of the ten leaching solutions did not exceed the limitation concentration of national standard. The∑PAHs concentrations( mg / kg) of five residues in sequence from high to low was tar( 175000),tar slag( 75630),precipitator dustⅠ( 405. 76),coke powder( 210. 35),precipitator dustⅡ( 37. 69),and the PAHs concentrations were much higher than the regulations of international public environment organization. The∑BEQ( mg / kg) of five residues in sequence from high to low was tar( 5761. 3),tar slag( 2058. 42),coke powder( 6. 59),precipitator dustⅠ( 0. 99),precipitator dustⅡ( 0. 07). Tar slag and tar were potentially more carcinogenic.