Han Weiwei, Han Fanghui, Zhang Ke
Beijing Key Laboratory of Urban Underground Space Engineering, Department of Civil Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Jiangsu Key Laboratory of Construction Materials, School of Materials Science and Engineering, Southeast University, Nanjing 211189, China.
Materials (Basel). 2022 Aug 16;15(16):5612. doi: 10.3390/ma15165612.
Copper and zinc tailing powder (CZTP) is finely ground waste after copper minerals and zinc minerals have been extracted from ores during beneficiation. CZTP has certain potential cementitious properties and can be used in composite cementitious materials. The pore size distribution and hydrate phase assemblage of the hardened samples are investigated using MIP and XRD. SEM is employed to examine the microstructure of the specimens. The chemically bonded water is used to measure the degree of hydration. CZTP lowers the hydration heat evolution rate and the total hydration heat. The hydration heat evolution rate reduces as the w/b ratio rises, whereas the total hydration heat of blended cement paste rises. CZTP diminishes the strength development of the Portland-CZTP system, and the strength decreases as the CZTP level increases. CZTP reduces the critical pore diameters of the Portland-CZTP system with w/b = 0.3 after curing for 3 d and 28 d, while increasing the critical pore diameters of samples with w/b = 0.45 at the same age. CZTP increases the gel micropores of Portland-CZTP. Although CZTP increases the pore volume content of blended cement pastes with w/b = 0.3, the volume of harmful pores decreases. The pore volume content of the Portland-CZTP system decreases as the w/b ratio increases. However, the volume of harmful pores increases with a higher w/b ratio. The main hydration products in the Portland-CZTP system are portlandite, ettringite, and C-S-H. CZTP mainly played the role of filling or acting as a microaggregate in the Portland-CZTP system.
铜锌尾矿粉（CZTP）是选矿过程中从矿石中提取铜矿物和锌矿物后经过细磨的废弃物。CZTP具有一定的潜在胶凝性能，可用于复合胶凝材料中。采用压汞法（MIP）和X射线衍射（XRD）研究硬化样品的孔径分布和水合物相组成。利用扫描电子显微镜（SEM）检测试样的微观结构。采用化学结合水来测量水化程度。CZTP降低了水化热释放速率和总水化热。随着水灰比（w/b）的增加，水化热释放速率降低，而混合水泥浆体的总水化热增加。CZTP降低了波特兰水泥-CZTP体系的强度发展，且随着CZTP掺量的增加强度降低。养护3天和28天后，CZTP降低了水灰比为0.3的波特兰水泥-CZTP体系的临界孔径，而在相同龄期增加了水灰比为0.45的样品的临界孔径。CZTP增加了波特兰水泥-CZTP体系的凝胶微孔。尽管CZTP增加了水灰比为0.3的混合水泥浆体的孔隙体积含量，但有害孔隙的体积减少。波特兰水泥-CZTP体系的孔隙体积含量随着水灰比的增加而降低。然而，较高的水灰比会使有害孔隙的体积增加。波特兰水泥-CZTP体系中的主要水化产物是氢氧化钙、钙矾石和C-S-H。在波特兰水泥-CZTP体系中，CZTP主要起到填充或作为微集料的作用。
