Details

Autor(en) / Beteiligte

• Liu, Lang
• Xin, Jie
• Huan, Chao
• Qi, Chongchong
• Zhou, Wenwu
• Song, KI-IL

Titel

Pore and strength characteristics of cemented paste backfill using sulphide tailings: Effect of sulphur content

Ist Teil von

• Construction & building materials, 2020-03, Vol.237, p.117452, Article 117452

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [Display omitted] •ACCNN and PCAS were efficient for the quantitative analysis of SEM images.•Sulphur content had a significant influence on the pore and strength characteristics of CPB.•UCS of CPB with increasing sulphur content was increased first and then decreased.•12% sulphur content was found to be an inflexion point for pore characteristics of CPB.•Porosity and the number of pores were found to be strongly correlated to the UCS of CPB. Cemented paste backfill (CPB) is a special composite prepared from recycled tailings, cement, and water. To ensure safe and efficient application of CPB for sulphide tailings, its pore and strength characteristics should be investigated. Although the strength of CPB has been determined well, identification of pore characteristics often requires manually adjusted threshold during the pre-treatment of microscopic images. In this study, an annealed chaotic competitive neural network was used for the pre-treatment of microscopic images and analysis of particles (pores) and cracks for quantitative pore analysis. The effect of sulphur content on the pore and strength characteristics of CPB specimens was evaluated in this study. Microscopic parameters (porosity, fractal dimension, etc.) were used to represent the pore characteristics, and unconfined compressive strength (UCS) was used to represent the CPB strength. The results show that the sulphur content plays a critical role in the pore and strength characteristics of CPB. For example, the porosity first decreased from 9.5% to 8.2% and then increased from 8.2% to 12.89% when the sulphur content was increased from 6.1% to 25%. Instead, the UCS of CPB specimens showed a slight increase from 2.51 MPa to 2.90 MPa before a clear decrease from 2.90 MPa to 0.571 MPa. The results indicate that it is necessary to evaluate the effect of sulphur content before the sulphide mineral tailings are recycled in CPB.