Development of a new controlled low strength filling material from the activation of copper slag: Influencing factors and mechanism analysis

Abstract

During copper ore smelting process, large amount of copper slag is created, which has excellent use in variance ways. In the common case, copper slag were deposited on the surface without treatment, which inevitably caused serious environmental problems. To deal with the pollution created and better utilize copper slag, a new controlled low strength filling material (CLSFM) was proposed for the copper slag from a mine in Africa.The filling cost of using CLSFM is equivalent to that of cement, as well as the method is more ecological and conforms to the local government environment policy. In order to study the influencing factors of this material, orthogonal test method and data visualization were used in the experiment, which make it possible to observe the effect of multifactor composite action on copper slag and the optimum ratio. The experimental results show that mechanical activation and alkali excitation can effectively activate the copper slag. Microscopic analysis shows that the main hydration product of CLSFM, C–S–H, makes the copper slag cementitious, and improves its structural strength. • The impact of Mechanical activation and Chemical activation on the copper slag was investigated. • Orthogonal test, regression analysis and data visualization were used to optimize the ratio. • The microstructure and hydration products of copper slag after mechanical and chemical excitation were analyzed.