Inorganic Chemicals Industry ›› 2025, Vol. 57 ›› Issue (9): 110-116.doi: 10.19964/j.issn.1006-4990.2024-0334

• Environment·Health·Safety • Previous Articles     Next Articles

Study on preparation of portland cement clinker from zinc tailings and its Zn2+ solidification

GAO Huafeng(), DONG Linlin, LIU Wei   

  1. Department of Civil Engineering,Zhengzhou College of Finance and Economics,Zhengzhou 450000,China
  • Received:2024-06-12 Online:2025-09-10 Published:2025-09-23

Abstract:

Zinc tailings are harmful industrial wastes.Clean and efficient utilization of zinc tailings not only has important environmental value,but also generates significant economic benefits.In this study,a silicate cement clinker was prepared with sphalerite tailings as additive,and the effect of tailings on the phase composition,microstructure,and hydration performance of clinker was studied.The transfer behavior of Zn2+ during the hydration process of clinker was explored.The passivation mechanism of Zn2+ leaching activity was also investigated at last.The results showed that the introduction of sphalerite tailings promoted the dissolution of f-CaO into liquid phase,thus accelerating C3S grain growth.While the synthesis of C3A phase was prevented after the addition of the sphalerite tailings,because of a reaction occurrence between ZnO and C3A to generate Ca14Al10Zn6O35.As a consequence,the 3 d compressive strength of cement slurry was gradually decreased,but the gradual improvements in 7 d and 28 d compressive strengths were present as a function of tailings addition.When 12% sphalerite tailings was introduced.A rubber sand specimen exhibited a 43.49 MPa compressive strength after 28 d curing.The passivation mechanism of Zn2+ leaching activity showed that some Zn2+ could be solid dissolved in C3S phase.But most of Zn2+ were distributed in the intermediate phase,and it was solidified through the synthesis of anhydrous Ca14Al10Zn6O35. More over,C3S containing Zn2+ generated hydrated calcium silicate gel after hydration,which could physically wrap the ion and restrain its leaching activity,thus collectively endowing the product with good environmental safety.The research results provided a new approach for the clean and efficient utilization of zinc tailings.

Key words: zinc tailings, cement clinker, Zn2+ solidification, composition and microstructure, performance

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