A Novel Model of Aggregate Gradation for Autoclaved Bricks from Tailings

Minerals

Hongqiang Li¹  Qiwu Zhang²  Shaoxian Song²  Wei Wang²  Tingting Zhang²  Yunliang Zhao²  Hao Yi² 

[1] School of Resources and Environmental Engineering, Wuhan Institute of Technology, Wuhan 430205, China;School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan 430070, China;

关键词: aggregate gradation;    model;    tailings;    autoclaved bricks;    strength;   

DOI  :  10.3390/min7070112

来源: DOAJ

【 摘 要 】

Mining tailings as a raw material for preparing autoclaved bricks have attracted much attention. The tailings subjected to milling always have the characteristic of fine granularity. However, the proportion of the fine aggregates in autoclaved bricks was very low using the current gradation formula, which impeded the utilization of the tailings. In this work, a novel model of aggregate gradation for autoclaved bricks from tailings has been presented, which was established through the following steps: (1) 91 groups of autoclaved bricks with different aggregate gradations were prepared, with the proportion of the fine aggregates (−0.15 mm) in the range of 40% to 100%; and (2) the particle size distributions of the finest and coarsest aggregates in the high-strength region were fitted to establish the model. The proportion of the fine aggregates calculated by the model could increase significantly compared with that using the current formula. To verify the novel model, autoclaved bricks from iron ore tailings were prepared using the model, with their mechanical and freezing resistance properties meeting the requirement of the highest-strength level. It was observed by SEM that the autoclaved bricks had compact structures with a few small pores owing to the reasonable aggregate gradation.

【 授权许可】

Unknown