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Abstract This study addresses the challenge of high volatility and low solidification rates of the semi-volatile heavy metal Pb during the co-processing of waste in cement kilns. To mitigate this, three modified mineral adsorbents(high-silicon, high-aluminum, and high-calcium), were synthesized using kaolin as the base material with equal mass substitution of silica fume, aluminum hydroxide, and calcium carbonate, respectively. The phase evolution of these systems was investigated across a temperature range of 0~1 450 ℃, and their influence on Pb solidification behavior was assessed. Clinker calcination experiments, determination of free calcium oxide content, total heavy metal content analysis, chemical form extraction, and leaching toxicity testing were employed to comprehensively evaluate the effects of each adsorbent on clinker burnability, Pb solidification rate, elemental distribution, and environmental safety. The results demonstrate that the high-silicon modified adsorbent, when added at a 1% dosage, significantly enhances the Pb solidification rate in clinker to 3.63 times that of the reference group and promotes a more uniform distribution of Pb within the clinker. Furthermore, Pb in KS predominantly exists in residual form(accounting for 95%), indicating strong chemical stability. The leaching concentration of Pb in the prepared cement slurry is substantially below the national standard limit, suggesting a low environmental risk. Consequently, this research offers both a theoretical foundation and a practical reference for selecting and implementing efficient, high-temperature resistant mineral adsorbents in cement kiln co-processing applications
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Published: 31 December 2025
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2026, Vol. 0 
