Effect of the Content of Micro-Active Copper Tailing on the Strength and Pore Structure of Cementitious Materials.

Liming Zhang,Dongsheng Song,Songbai Liu

doi:10.3390/ma12111861

Abstract

This study investigates the effect of micr-oaggregate filling with copper tailing on the pore structure of cement paste containing copper tailing (CPCT). The particle size of the CPCT and the pore structure of CPCT were analyzed by laser particle size analysis and mercury instruction porosimetry (MIP). Results showed that at the early stage of curing time, with increasing copper tailing content, the compressive strength of cement mortar with copper tailing (CMCT) was lower, and the porosity and pore diameter of CPCT were higher and greater; with the extension of curing age, when the content of copper tailing was less than 30%, the compressive strength of CMCT and the porosity of CPCT changed slightly with the increase of the content of copper tailing. However, the maximum hole diameter of CPCT decreased gradually (a curing age between 7 d and 365 d under standard conditions). Scanning electron microscopy analysis showed that at the early stage of cement hydration in the CPCT, the copper tailing did not fill the pores in CPCT well, while in the later stage of cement hydration, the microaggregates of copper tailing filled the pores well and closely combined with the surrounding hydration products. In the later stage of cement hydration, the microaggregate filling of copper tailing was primarily responsible for the strength increase of the CMCT.

Highlights

The inventory of copper tailings in Jiangxi (Figure 1) is 496.17 million tons [1], with an annual increase of 44 million tons—the highest in Asia
When the curing age was less than 180 d, the porosity of the cement paste containing tailing (CPCT) increased with increasing copper tailing content; on the other hand, when the curing age was more than 180 d, the copper tailing content had little influence on the porosity of the (c) 365 d
When the curing age was less than d, the porosity of the porosity of the CPCT increased with increasing copper tailing content; on the other hand, when the tailing content; on the other whenon the curing ageof was curingincreased age was with moreincreasing than 180 d,copper the copper tailing content had littlehand, influence the porosity the more than 180 d, the copper tailing content had little influence on the porosity of the CPCT

Summary

Introduction

The inventory of copper tailings in Jiangxi (Figure 1) is 496.17 million tons [1], with an annual increase of 44 million tons—the highest in Asia. Domestic and international experts [4,5,6,7,8] have focused on the preparation of concrete as a mineral admixture and studied its performance. They found that when the content of copper tailing slag is 5% of the cementing material, the performance of concrete can be improved, but beyond this content, the performance is deteriorated. There is little research on the microscopic mechanism, especially on the pore structure of cement mortar with copper tailing (CMCT).

Methods

Results

Conclusion