China Nonferrous Metallurgy

Aiming at the problem of low activity of copper slag due to high iron content in copper slag, a method of removing magnetic ore powder in copper slag by magnetic separation pretreatment is proposed to improve activity of copper slag. SEM, XRD and other methods were used to study the change of the phase structure of copper slag by magnetic separation, and the copper slag powder without magnetic separation and one with magnetic separation were used as the main material to prepare copper slag powder cementitious materials.The effects of magnetic separation on compressive strength of cementitious materials were investigated.The results showed that the magnetic separation pretreatment of the copper slag could reduce the content of magnetic oxides in some areas of the copper slag, which would change the mineral structure; the magnetic separation rate could increase with the decrease of the particle size of the copper slag, and when the particle size of the copper slag was less than 74, the magnetic separation rate reached 9.8%; the compressive strength of the cementitious material prepared by using the magnetic separation copper slag increased by 25%, 32.5%, and 61.6% respectively after 3d, 7d, and 28d of curing, the 28d strength reached 20.18MPa; and magnetic separation could change mineral structure of copper slag and improve compressive strength of cementitious materials. Magnetic separation pretreatment provides new ideas for further improving the activity of copper slag powder, and has certain reference value for practical engineering.