Strength Characteristics of Iron Tailings Blended Soil as a Road Base Material

Jiannan Tong,Yonghua Wang,Xujing Niu,Yunhua Lu

doi:10.3390/app11167587

Abstract

Cement and ionic curing agent were blended with iron tailings (ITS) and natural soil to prepare a new road base material. 7-d unconfined compressive strength (UCS) was selected as the evaluation index for determining the optimal mix ratio. The results reveal that the 7-d UCS always increases with the increase of cement content, and firstly increases with the increase of curing agent content and then tends to remain stable, exhibiting an increasing trend first and then dropping with the increase of ITS content. In lieu of this, the optimum ratio of iron tailings blended soil (ITBS) is determined as follows: ITS and soil are mixed in ratio of 50:50, and cement and soil curing agent account for 5% and 2% of the total mass, respectively. The results of splitting strength and flexural-tensile strength tests show that these strengths of the ITBS always increase with the curing age, and firstly increases and then decreases with the increase in ITS content. XRD and SEM analyses show that the ratio of ITS to soil significantly influences the micro-pore structure of the blended soil. At an ITS to soil ratio of 50%:50%, the combination of soil and ITS particles is the closest which results in the highest strength attainment.

Highlights

With the rapid development of Chinese society across China, the process of road transportation is constantly advancing and cutting-edge technologies are being applied
Iron tailings were obtained from an iron mine area situated in Anhui Province for 70.82%, while Fe2 O3 and Al2 O3 account for 13.66% and 5.08%, respectively
The iron tailings (ITS) and soil were mixed and stirred and the soil curing agent was added to the weighed water for dilution such that 80% diluted solution was sprayed into the modified soil to ensure uniform stirring

Summary

Introduction

With the rapid development of Chinese society across China, the process of road transportation is constantly advancing and cutting-edge technologies are being applied. The highway construction system has improved to a large extent, the shortage of the raw materials such as sand and gravel and the escalating prices increase project costa [1], resulting in a series of constraints. As an important part of its mineral resources, iron ore mining in China discharges nearly 300 million tons of iron tailings (ITS). Annually, such that a large amount of these can only be piled up in the form of tailings ponds. The utilization rate of ITS resources in China is only about 50% [2,3]. The elevated levels of the tailing ponds are largely attributed to the increase of ITS discharge. The rational utilization of ITS resources is of immense significance

Methods

Results

Conclusion