Mechanical Properties and Toxicity Risks of Lead-Zinc Sulfide Tailing-Based Construction Materials.

Yang Zhou,Tao Chen,Xinlian Duan,Bo Yan,Lili Li

doi:10.3390/ma14112940

Abstract

The leaching residue of the lead–zinc sulfide tailing (LRT) is the only residue generated from the tailing leaching recovery process; it is a typical hazardous material for its high heavy-metal contents and high acidity. Due to the large output of LRT, and because its main components are Ca, Si, and Al, the preparation of building construction materials with LRT was studied. The results showed that when the LRT addition is less than 47%, with the ordinary Portland cement (OPC) and fly ash (FA) added and the curing conditions appropriate, the strength values of the tested specimens meet the M15 Class of the autoclaved lime sand brick standard (GB/T 16753-1997). The carbonization coefficient and drying shrinkage of the specimen were 0.79 and smaller than 0.42, respectively. As the SEM, TG, and XRD analysis have shown, the LRT can chemically react with additives to form stable minerals. The heavy metal contents that were leached out well met the limits in GB5085.3-2007. Based on the high addition of the LRT, the good strength and lower heavy metals were leached out of the prepared test specimen, and the tailing could be reused completely with the leaching recovery and the LRT reuse process. LRT can be used to replace OPC, allowing more sustainable concrete production and improved ecological properties of LRT.

Highlights

Millions of tons of Pb–Zn tailings have been stored in tailing impoundments without any protection
After metals recovery from Lead–Zinc Sulfide Tailings, a large amount of leaching residue of Lead–Zinc Sulfide Tailings (LRT) will be produced [1], and little attention has been paid to its disposal so far
The LRT output was varied based upon the different leaching recovery procedures [2,3], and its storage was stint by its acidity and the heavy metals

Summary

Introduction

Millions of tons of Pb–Zn tailings have been stored in tailing impoundments without any protection. Metals could be recycled from the tailings with separation and intensive leaching process. The LRT output was varied based upon the different leaching recovery procedures [2,3], and its storage was stint by its acidity and the heavy metals. LRT was one classical type of solid waste, and its main components are elements such as Si, Ca, Al, and Fe [4,5,6] These elements are just the main components of construction materials [5,7]. The recycling of the residue could realize zero emissions from the tailings’ recovery but would offer a huge material for the building industry, which is a more effective resource recovery alternative [8,9,10,11,12]. There are varied and huge demands for this material, such as the reclamation of the tailings impoundments, the hardening of the mining area, and the filling for mining wells

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Results

Conclusion