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Preparation of environmentally friendly and energy-saving autoclaved aerated concrete using gold tailings

Year: 2019

Type: article

Abstract: Gold tailings (GTS) are solid wastes from gold mining operations by mining enterprises.At present, China's GTS are basically in a state of tailings storage.According to statistics, from 2014 to 2018, the national GTS emissions reached 920 million tons, which brought serious environmental and safety problems to the mining area.Therefore, it has become a top priority to conduct secondary development and utilization of resources for the GTS [1].Due to its high silicon content, the GTS can be used as the admixtures to prepare autoclaved aerated concrete (AAC).This can effectively absorb a large amount of GTS, which makes it one of the key projects of the 12th Five-Year Plan for comprehensive utilization of bulk industrial solid wastes [2].AAC is a porous building material, and one of its most outstanding advantages is light weight, while the porosity is the cause of its light weigh [3,4].Some literatures show that the reason why the AAC's strength can be ensured under light weight is that during the autoclaving process, the hardened aerated concrete produced a large amount of well-crystalline tobermorite and crystalline phase calcium silicate hydrate (CSH), which cross-grow with gel-like substances to compact the structure and thus improve product strength and performance [5][6][7][8][9][10][11][12].After crushing, grinding and beneficiation, the fine-grained GTS are rich in silicate minerals.They differ greatly in the physical and chemical characteristics from acid materials such as fly ash and river sand that are commonly used in the production of aerated concrete [13,14].The active ingredients of silicate minerals, such as Al 2 O 3 and

Source: Journal of New Materials for Electrochemical Systems

DOI: 10.14447/jnmes.v22i3.a08

Authors: Feihua Yang, Xiaoying Liang, Yi Zhu, Changlong Wang, Gaofei Zhao, Xiaowei Cui