Mechanical and Electrical Characteristics of Graphite Tailing Concrete

Hongbo Liu,Kun Liu,Zhu Lan,Dashuang Zhang

doi:10.1155/2018/9297628

Abstract

The graphite tailing causes serious environmental pollution, and the pollution problem becomes worse and worse with the increase in graphite demands. This paper focuses on the graphite tailing concrete, which can alleviate the environment problem through utilizing graphite tailings. With the orthogonal experimental design, 16 groups of specimens were designed to investigate the compressive strength of the graphite tailing concrete, and each group had 6 specimens. The significance sequence of the influencing factors for the compressive strength was studied, including the ratio of water to cement, sand ratio, graphite tailings content, and carbon fiber content. The optimal contents of graphite tailings and carbon fiber were obtained from the further experimental study on the electrical characteristics of the graphite tailing concrete, and a regression analysis was conducted to develop the predictive mixture design relationships for the electrical resistivity of the conductive graphite tailing concrete. The experimental results show that the conductive concrete mixture containing graphite tailings and carbon fiber has satisfactory mechanical strength along with well electrical conductivity. With the increase in graphite tailings content, the compressive strength decreases slowly, but the electrical resistivity decreases much more obviously. Predictions with the proposed relationship are in reasonable agreement with experimental results. This study provides references for the graphite tailing utilization alleviating the environment problems.

Highlights

Graphite tailings are derived from froth flotation process of graphite ores [1]
Conductive materials [10,11,12] that replace ordinary concrete aggregates provide with high electrical conductivity, and conductive materials usually include graphite, steel fiber, and carbon fiber [13]
When the graphite dosage is greater than 15%, the increase of the conductivity is not obvious, but the compressive strength decreases remarkably [15]. ere is some graphite left in the graphite tailings, so the graphite tailings can provide conductive materials for the conductive concrete [1]. e additions of graphite tailings can reduce the electrical resistivity of concrete, and the tailings have less effect on the strength of concrete than pure graphite because the graphite fuses with rock

Summary

Introduction

Graphite tailings are derived from froth flotation process of graphite ores [1]. With the increase in graphite production, the massive tailings containing hydrocarbon oil, diesel oil, and heavy metals have been generated during the past years in China, which pollute environment and occupy a large amount of land. e tailing dust flies with the wind, which causes serious air contamination. Based on the above discussion, the steel fiber is not considered and the carbon fiber is adopted in the graphite tailing concrete as additional conductive material in this study, because the stability is a key issue for construction material. There are four key factors affecting the compressive strength of the conductive concrete including the ratio of water to cement, sand ratio, graphite tailings content, and carbon fiber content. E effects of the ratio of water to cement, sand ratio, graphite tailings content, and carbon fiber content on mechanical characteristics are studied experimentally based on the orthogonal experimental design, and the electrical characteristics are studied with the four-electrode method. E optimal contents of graphite tailings and carbon fiber are studied, and the mixture design relationships for the electrical resistivity are predicted by regression analysis Graphite tailings are added to the conventional concrete to make the conductive graphite tailing concrete, and carbon fibers are added to further improve the electrical conductivity. e effects of the ratio of water to cement, sand ratio, graphite tailings content, and carbon fiber content on mechanical characteristics are studied experimentally based on the orthogonal experimental design, and the electrical characteristics are studied with the four-electrode method. e optimal contents of graphite tailings and carbon fiber are studied, and the mixture design relationships for the electrical resistivity are predicted by regression analysis

Experimental Materials

Compressive Strength

Findings

Electrical Characteristics