High value-added resource treatment of antimony tailings: preparation of high-strength lightweight foam concrete materials

Abstract

The continuous exploitation of global mineral resources leaves ever increasing tailings, which leads to the accumulation of antimony tailings and causes antimony pollution accidents. The complex chemical composition and associated harmful elements of antimony tailings limit their large-scale consumption and high-value comprehensive utilization. To realize the solidification/stabilization of antimony tailings with heavy metals and achieve large-scale high-value utilization, in this paper, high-strength and lightweight concrete materials based on antimony tailing powder were prepared by using antimony tailing powder as the main raw material, and cement clinker, activator, coagulant and foaming agent as the supplements. In this manner, the performance of high-strength and lightweight concrete materials were investigated and optimized in terms of mechanical properties, waterproofing properties, micromorphology, etc. The experiment results show that the decrease of the compressive strength and apparent density of the specimen slurry is due to the increased amount of antimony tailing micronized powder. Additionally, the influence of different foaming agents on the material is significant. With the addition of antimony tailing of 50% and H2O2 of 0.6% into the cementitious material of PC42.5, the material presents optimal high-strength and lightweight performance. Moreover, the compressive strength at 28 d reaches up to 36.2 MPa, and the dry apparent density is as high as 1449.2188 kg/m3. In addition, the optimal system has been optimized in terms of waterproof performance. Softening coefficient of the composite with optimized composition was increased by 55.1%, reaching 0.86, which is sufficiently high for waterproof application.