Research On Using Lead-zinc Tailings As An Ingredient Of Cement

Abstract:The large number of metal tailings discharged in the process of mining leads to serious environmental problems and security risks. The most effective way to solve this problem is comprehensive utilization of tailings. Metal tailings which have similar chemical composition to cement raw materials, low melting point and rich trace elements are favorable materials to producing cement. This paper introduced the research on using lead-zinc tailings as a cement ingredient. Six prescriptions were designed according to the characteristics of raw material. The raw materials were calcined at the temperatures of1300℃,1350℃and1400℃respectively. Based on the results of burnability test, the experimental research of performance was carried out by adjusting the calcination temperature to1350℃,1400℃,1450℃and expanding the scope of the tailings. The curing effect of heavy metals for Pb, Zn, Cd in clinker was researched by determining the content of Pb, Zn, Cd in the raw and clinker of performance testing samples.Meanwhile,the performance of lead-zinc tailings used as mixed material was researched.The results of f-CaO and X-diffraction analysis of clinker show that the raw prescriptions of lead-zinc tailings have good burnability. The clinkers could be produced in temperature at least50℃lower than prescriptions of Hunan south cement company.The compressive strength of30.4MPa achieved with the addition of7%tailings at the calcined temperature of1350℃,which closes to the standard of R32.5. The content of Pb, Zn, Cd in samples of performance research were tested.The results show that the cure rate of Pb and Cd are about10%and25%respectively, the cure rate of Zn is up to98.23%.The results of mixed material experiment show that the lead-zinc tailings is a potential raw material of cement.As mixed percentage of tailings keeps under25percent, cement can reach32.5R under conditions that the compressive strength of clinker itself is only37.1MPa.