Study On Migration Characteristics Of Heavy Metals Pb And Cu In Waste Incineration Under Chlorine Conditions

In this paper,Sk2-4-12 tubular incinerator is selected to simulate the waste incineration process.The experimental raw material is the actual classified domestic waste in Shanghai.The contents of heavy metals Pb and Cu in the incineration products are determined by inductively coupled plasma atomic emission spectrometry(ICP-AES).The additive sulfur and sulfide(S,Na2S and Na2SO4)are investigated respectively Effects of oxides(CaO,SiO2 and Al2O3)on the migration characteristics of heavy metals Pb and Cu in waste incineration under different chlorine containing conditions(PVC and NaCl).The effects of sulfur and sulfide on Pb migration characteristics are as follows:when NaCl is added,sulfur and sulfide inhibit Pb volatilization at 600℃ and 700℃,and the inhibition effect is Na2S>Na2SO4>S;At 800℃ and 900℃,sulfur and sulfide promote Pb volatilization,and the promotion effect is Na2SO4>Na2S>S.When PVC was added,sulfur and sulfide inhibited Pb volatilization at 600℃,700℃ and 800℃,and the inhibition effect was Na2S>Na2SO4>S;At 900℃,sulfur and sulfide turn to promote Pb volatilization,and the promotion effect is Na2SO4>Na2S>S.The effects of sulfur and sulfide on Cu migration characteristics are as follows:when NaCl is added,sulfur and sulfide inhibit Cu volatilization at 600℃ and 700℃,and the inhibition effect is Na2SO4>Na2S>S;At 800℃,Na2S and Na2SO4 promoted the volatilization of Cu,the promoting effect was Na2SO4>Na2S,and S still inhibited the volatilization of Cu;When the temperature rises to 900℃,sulfur and sulfide promote the volatilization of Cu,and the promotion effect is Na2SO4>Na2S>S.When PVC was added,sulfur and sulfide inhibited Cu volatilization at 600℃ and 700℃,and the inhibition effect was Na2SO4>Na2S>S;At 800℃,the inhibition effect is S>Na2SO4>Na2S;At 900 ℃,Na2S and Na2SO4 promoted the volatilization of Cu,and the promoting effect was Na2SO4>Na2S,but s still inhibited the volatilization of Cu.The effects of oxides on Pb migration characteristics are as follows:when NaCl is added,SiO2 and Cao inhibit Pb volatilization.At 600 ℃,700℃ and 800℃,SiO2>CaO,and CaO is slightly stronger than SiO2 at 900℃;Al2O3 has no significant effect on Pb volatilization at 600℃ and 700℃,but Al2O3 promotes Pb volatilization at 800℃ and 900℃.When PVC was added,Al2O3 had no significant effect on the migration characteristics of Pb;SiO2 and CaO inhibited Pb volatilization at all experimental temperatures,and the inhibition effect was SiO2>CaO.The effect of oxide on Cu migration characteristics is that when NaCl or PVC is added,SiO2,Al2O3 and CaO inhibit Cu volatilization at all experimental temperatures,and the inhibition effect is SiO2>Al2O3>CaO.In addition,the thermodynamic simulation software HSC chemistry 6.0 is used to calculate the thermodynamic equilibrium of the transformation and distribution of heavy metals Pb and Cu in the process of waste incineration.According to the thermodynamic simulation results,the transformation process of heavy metals is deeply expounded,and the influence mechanism of various additives on the migration and distribution characteristics of Pb and Cu is further verified and analyzed.The thermodynamic simulation results are also in good agreement with the experimental phenomena.